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Sample records for metalloproteinase cleavage sites

  1. Degradation of tropoelastin by matrix metalloproteinases--cleavage site specificities and release of matrikines

    DEFF Research Database (Denmark)

    Heinz, Andrea; Jung, Michael C; Duca, Laurent

    2010-01-01

    To provide a basis for the development of approaches to treat elastin-degrading diseases, the aim of this study was to investigate the degradation of the natural substrate tropoelastin by the elastinolytic matrix metalloproteinases MMP-7, MMP-9, and MMP-12 and to compare the cleavage site...

  2. Cleavage/alteration of interleukin-8 by matrix metalloproteinase-9 in the female lower genital tract.

    Science.gov (United States)

    Zariffard, M Reza; Anastos, Kathryn; French, Audrey L; Munyazesa, Elisaphane; Cohen, Mardge; Landay, Alan L; Spear, Gregory T

    2015-01-01

    Interleukin-8 (IL-8, CXCL8) plays important roles in immune responses at mucosal sites including in the lower genital tract. Since several types of bacteria produce proteases that cleave IL-8 and many types of bacteria can be present in lower genital tract microbiota, we assessed genital fluids for IL-8 cleavage/alteration. Genital fluids collected by lavage from 200 women (23 HIV-seronegative and 177 HIV-seropositive) were tested for IL-8 cleavage/alteration by ELISA. IL-8 cleaving/altering activity was observed in fluids from both HIV-positive (28%) and HIV-negative women (35%). There was no clear relationship between the activity and the types of bacteria present in the lower genital tract as determined by high-throughput sequencing of the 16S rRNA gene. Protease inhibitors specific for matrix metalloproteinases (MMPs) reduced the activity and a multiplex assay that detects both inactive and active MMPs showed the presence of multiple MMPs, including MMP-1, -3, -7, -8, -9, -10 and -12 in genital secretions from many of the women. The IL-8-cleaving/altering activity significantly correlated with active MMP-9 as well as with cleavage of a substrate that is acted on by several active MMPs. These studies show that multiple MMPs are present in the genital tract of women and strongly suggest that MMP-9 in genital secretions can cleave IL-8 at this mucosal site. These studies suggest that MMP-mediated cleavage of IL-8 can modulate inflammatory responses in the lower genital tract.

  3. Inhibition of Cellular Adhesion by Immunological Targeting of Osteopontin Neoepitopes Generated through Matrix Metalloproteinase and Thrombin Cleavage.

    Science.gov (United States)

    Jürets, Alexander; Le Bras, Marie; Staffler, Günther; Stein, Gesine; Leitner, Lukas; Neuhofer, Angelika; Tardelli, Matteo; Turkof, Edvin; Zeyda, Maximilian; Stulnig, Thomas M

    2016-01-01

    Osteopontin (OPN), a secreted protein involved in inflammatory processes and cancer, induces cell adhesion, migration, and activation of inflammatory pathways in various cell types. Cells bind OPN via integrins at a canonical RGD region in the full length form as well as to a contiguous cryptic site that some have shown is unmasked upon thrombin or matrix metalloproteinase cleavage. Thus, the adhesive capacity of osteopontin is enhanced by proteolytic cleavage that may occur in inflammatory conditions such as obesity, atherosclerosis, rheumatoid arthritis, tumor growth and metastasis. Our aim was to inhibit cellular adhesion to recombinant truncated proteins that correspond to the N-terminal cleavage products of thrombin- or matrix metalloproteinase-cleaved OPN in vitro. We specifically targeted the cryptic integrin binding site with monoclonal antibodies and antisera induced by peptide immunization of mice. HEK 293 cells adhered markedly stronger to truncated OPN proteins than to full length OPN. Without affecting cell binding to the full length form, the raised monoclonal antibodies specifically impeded cellular adhesion to the OPN fragments. Moreover, we show that the peptides used for immunization were able to induce antisera, which impeded adhesion either to all OPN forms, including the full-length form, or selectively to the corresponding truncated recombinant proteins. In conclusion, we developed immunological tools to selectively target functional properties of protease-cleaved OPN forms, which could find applications in treatment and prevention of various inflammatory diseases and cancers.

  4. Trichomonas vaginalis Metalloproteinase Induces mTOR Cleavage of SiHa Cells

    Science.gov (United States)

    Quan, Juan-Hua; Choi, In-Wook; Yang, Jung-Bo; Zhou, Wei; Cha, Guang-Ho; Zhou, Yu; Ryu, Jae-Sook

    2014-01-01

    Trichomonas vaginalis secretes a number of proteases which are suspected to be the cause of pathogenesis; however, little is understood how they manipulate host cells. The mammalian target of rapamycin (mTOR) regulates cell growth, cell proliferation, cell motility, cell survival, protein synthesis, and transcription. We detected various types of metalloproteinases including GP63 protein from T. vaginalis trophozoites, and T. vaginalis GP63 metalloproteinase was confirmed by sequencing and western blot. When SiHa cells were stimulated with live T. vaginalis, T. vaginalis excretory-secretory products (ESP) or T. vaginalis lysate, live T. vaginalis and T. vaginalis ESP induced the mTOR cleavage in both time- and parasite load-dependent manner, but T. vaginalis lysate did not. Pretreatment of T. vaginalis with a metalloproteinase inhibitor, 1,10-phenanthroline, completely disappeared the mTOR cleavage in SiHa cells. Collectively, T. vaginalis metallopeptidase induces host cell mTOR cleavage, which may be related to survival of the parasite. PMID:25548410

  5. Dataset of cocoa aspartic protease cleavage sites

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    Katharina Janek

    2016-09-01

    Full Text Available The data provide information in support of the research article, “The cleavage specificity of the aspartic protease of cocoa beans involved in the generation of the cocoa-specific aroma precursors” (Janek et al., 2016 [1]. Three different protein substrates were partially digested with the aspartic protease isolated from cocoa beans and commercial pepsin, respectively. The obtained peptide fragments were analyzed by matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF-MS/MS and identified using the MASCOT server. The N- and C-terminal ends of the peptide fragments were used to identify the corresponding in-vitro cleavage sites by comparison with the amino acid sequences of the substrate proteins. The same procedure was applied to identify the cleavage sites used by the cocoa aspartic protease during cocoa fermentation starting from the published amino acid sequences of oligopeptides isolated from fermented cocoa beans. Keywords: Aspartic protease, Cleavage sites, Cocoa, In-vitro proteolysis, Mass spectrometry, Peptides

  6. Matrix metalloproteinase-1 facilitates MSC migration via cleavage of IGF-2/IGFBP2 complex.

    Science.gov (United States)

    Guan, Shou P; Lam, Alan T L; Newman, Jennifer P; Chua, Kevin L M; Kok, Catherine Y L; Chong, Siao T; Chua, Melvin L K; Lam, Paula Y P

    2018-01-01

    The specific mechanism underlying the tumor tropism of human mesenchymal stem cells (MSCs) for cancer is not well defined. We previously showed that the migration potential of MSCs correlated with the expression and protease activity of matrix metalloproteinase (MMP)-1. Furthermore, highly tumor-tropic MSCs expressed higher levels of MMP-1 and insulin-like growth factor (IGF)-2 than poorly migrating MSCs. In this study, we examined the functional roles of IGF-2 and MMP-1 in mediating the tumor tropism of MSCs. Exogenous addition of either recombinant IGF-2 or MMP-1 could stimulate MSC migration. The correlation between IGF-2, MMP-1 expression, and MSC migration suggests that MMP-1 may play a role in regulating MSC migration via the IGF-2 signaling cascade. High concentrations of IGF binding proteins (IGFBPs) can inhibit IGF-stimulated functions by blocking its binding to its receptors and proteolysis of IGFBP is an important mechanism for the regulation of IGF signaling. We thus hypothesized that MMP-1 acts as an IGFBP2 proteinase, resulting in the cleavage of IGF-2/IGFBP2 complex and extracellular release of free IGF-2. Indeed, our results showed that conditioned media from highly migrating MSCs, which expressed high levels of MMP-1, cleaved the IGF-2/IGFBP2 complex. Taken together, these results showed that the MMP-1 secreted by highly tumor-tropic MSCs cleaved IGF-2/IGFBP2 complex. Free IGF-2 released from the complex may facilitate MSC migration toward tumor.

  7. Pripper: prediction of caspase cleavage sites from whole proteomes

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    Salmi Jussi

    2010-06-01

    Full Text Available Abstract Background Caspases are a family of proteases that have central functions in programmed cell death (apoptosis and inflammation. Caspases mediate their effects through aspartate-specific cleavage of their target proteins, and at present almost 400 caspase substrates are known. There are several methods developed to predict caspase cleavage sites from individual proteins, but currently none of them can be used to predict caspase cleavage sites from multiple proteins or entire proteomes, or to use several classifiers in combination. The possibility to create a database from predicted caspase cleavage products for the whole genome could significantly aid in identifying novel caspase targets from tandem mass spectrometry based proteomic experiments. Results Three different pattern recognition classifiers were developed for predicting caspase cleavage sites from protein sequences. Evaluation of the classifiers with quality measures indicated that all of the three classifiers performed well in predicting caspase cleavage sites, and when combining different classifiers the accuracy increased further. A new tool, Pripper, was developed to utilize the classifiers and predict the caspase cut sites from an arbitrary number of input sequences. A database was constructed with the developed tool, and it was used to identify caspase target proteins from tandem mass spectrometry data from two different proteomic experiments. Both known caspase cleavage products as well as novel cleavage products were identified using the database demonstrating the usefulness of the tool. Pripper is not restricted to predicting only caspase cut sites, but it gives the possibility to scan protein sequences for any given motif(s and predict cut sites once a suitable cut site prediction model for any other protease has been developed. Pripper is freely available and can be downloaded from http://users.utu.fi/mijopi/Pripper. Conclusions We have developed Pripper, a tool for

  8. Variable context Markov chains for HIV protease cleavage site prediction.

    Science.gov (United States)

    Oğul, Hasan

    2009-06-01

    Deciphering the knowledge of HIV protease specificity and developing computational tools for detecting its cleavage sites in protein polypeptide chain are very desirable for designing efficient and specific chemical inhibitors to prevent acquired immunodeficiency syndrome. In this study, we developed a generative model based on a generalization of variable order Markov chains (VOMC) for peptide sequences and adapted the model for prediction of their cleavability by certain proteases. The new method, called variable context Markov chains (VCMC), attempts to identify the context equivalence based on the evolutionary similarities between individual amino acids. It was applied for HIV-1 protease cleavage site prediction problem and shown to outperform existing methods in terms of prediction accuracy on a common dataset. In general, the method is a promising tool for prediction of cleavage sites of all proteases and encouraged to be used for any kind of peptide classification problem as well.

  9. Active site mutations change the cleavage specificity of neprilysin.

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    Travis Sexton

    Full Text Available Neprilysin (NEP, a member of the M13 subgroup of the zinc-dependent endopeptidase family is a membrane bound peptidase capable of cleaving a variety of physiological peptides. We have generated a series of neprilysin variants containing mutations at either one of two active site residues, Phe(563 and Ser(546. Among the mutants studied in detail we observed changes in their activity towards leucine(5-enkephalin, insulin B chain, and amyloid β(1-40. For example, NEP(F563I displayed an increase in preference towards cleaving leucine(5-enkephalin relative to insulin B chain, while mutant NEP(S546E was less discriminating than neprilysin. Mutants NEP(F563L and NEP(S546E exhibit different cleavage site preferences than neprilysin with insulin B chain and amyloid ß(1-40 as substrates. These data indicate that it is possible to alter the cleavage site specificity of neprilysin opening the way for the development of substrate specific or substrate exclusive forms of the enzyme with enhanced therapeutic potential.

  10. Active site specificity profiling datasets of matrix metalloproteinases (MMPs 1, 2, 3, 7, 8, 9, 12, 13 and 14

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    Ulrich Eckhard

    2016-06-01

    Full Text Available The data described provide a comprehensive resource for the family-wide active site specificity portrayal of the human matrix metalloproteinase family. We used the high-throughput proteomic technique PICS (Proteomic Identification of protease Cleavage Sites to comprehensively assay 9 different MMPs. We identified more than 4300 peptide cleavage sites, spanning both the prime and non-prime sides of the scissile peptide bond allowing detailed subsite cooperativity analysis. The proteomic cleavage data were expanded by kinetic analysis using a set of 6 quenched-fluorescent peptide substrates designed using these results. These datasets represent one of the largest specificity profiling efforts with subsequent structural follow up for any protease family and put the spotlight on the specificity similarities and differences of the MMP family. A detailed analysis of this data may be found in Eckhard et al. (2015 [1]. The raw mass spectrometry data and the corresponding metadata have been deposited in PRIDE/ProteomeXchange with the accession number http://www.ebi.ac.uk/pride/archive/projects/PXD002265.

  11. P-I Snake Venom Metalloproteinase Is Able to Activate the Complement System by Direct Cleavage of Central Components of the Cascade

    Science.gov (United States)

    Pidde-Queiroz, Giselle; Magnoli, Fábio Carlos; Portaro, Fernanda C. V.; Serrano, Solange M. T.; Lopes, Aline Soriano; Paes Leme, Adriana Franco; van den Berg, Carmen W.; Tambourgi, Denise V.

    2013-01-01

    Background Snake Venom Metalloproteinases (SVMPs) are amongst the key enzymes that contribute to the high toxicity of snake venom. We have recently shown that snake venoms from the Bothrops genus activate the Complement system (C) by promoting direct cleavage of C-components and generating anaphylatoxins, thereby contributing to the pathology and spread of the venom. The aim of the present study was to isolate and characterize the C-activating protease from Bothrops pirajai venom. Results Using two gel-filtration chromatography steps, a metalloproteinase of 23 kDa that activates Complement was isolated from Bothrops pirajai venom. The mass spectrometric identification of this protein, named here as C-SVMP, revealed peptides that matched sequences from the P-I class of SVMPs. C-SVMP activated the alternative, classical and lectin C-pathways by cleaving the α-chain of C3, C4 and C5, thereby generating anaphylatoxins C3a, C4a and C5a. In vivo, C-SVMP induced consumption of murine complement components, most likely by activation of the pathways and/or by direct cleavage of C3, leading to a reduction of serum lytic activity. Conclusion We show here that a P-I metalloproteinase from Bothrops pirajai snake venom activated the Complement system by direct cleavage of the central C-components, i.e., C3, C4 and C5, thereby generating biologically active fragments, such as anaphylatoxins, and by cleaving the C1-Inhibitor, which may affect Complement activation control. These results suggest that direct complement activation by SVMPs may play a role in the progression of symptoms that follow envenomation. PMID:24205428

  12. Cleavage sites within the poliovirus capsid protein precursors

    International Nuclear Information System (INIS)

    Larsen, G.R.; Anderson, C.W.; Dorner, A.J.; Semler, B.L.; Wimmer, E.

    1982-01-01

    Partial amino-terminal sequence analysis was performed on radiolabeled poliovirus capsid proteins VP1, VP2, and VP3. A computer-assisted comparison of the amino acid sequences obtained with that predicted by the nucleotide sequence of the poliovirus genome allows assignment of the amino terminus of each capsid protein to a unique position within the virus polyprotein. Sequence analysis of trypsin-digested VP4, which has a blocked amino terminus, demonstrates that VP4 is encoded at or very near to the amino terminus of the polyprotein. The gene order of the capsid proteins is VP4-VP2-VP3-VP1. Cleavage of VP0 to VP4 and VP2 is shown to occur between asparagine and serine, whereas the cleavages that separate VP2/VP3 and VP3/VP1 occur between glutamine and glycine residues. This finding supports the hypothesis that the cleavage of VP0, which occurs during virion morphogenesis, is distinct from the cleavages that separate functional regions of the polyprotein

  13. Coronavirus 3CLpro proteinase cleavage sites: Possible relevance to SARS virus pathology

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    Blom Nikolaj

    2004-06-01

    Full Text Available Abstract Background Despite the passing of more than a year since the first outbreak of Severe Acute Respiratory Syndrome (SARS, efficient counter-measures are still few and many believe that reappearance of SARS, or a similar disease caused by a coronavirus, is not unlikely. For other virus families like the picornaviruses it is known that pathology is related to proteolytic cleavage of host proteins by viral proteinases. Furthermore, several studies indicate that virus proliferation can be arrested using specific proteinase inhibitors supporting the belief that proteinases are indeed important during infection. Prompted by this, we set out to analyse and predict cleavage by the coronavirus main proteinase using computational methods. Results We retrieved sequence data on seven fully sequenced coronaviruses and identified the main 3CL proteinase cleavage sites in polyproteins using alignments. A neural network was trained to recognise the cleavage sites in the genomes obtaining a sensitivity of 87.0% and a specificity of 99.0%. Several proteins known to be cleaved by other viruses were submitted to prediction as well as proteins suspected relevant in coronavirus pathology. Cleavage sites were predicted in proteins such as the cystic fibrosis transmembrane conductance regulator (CFTR, transcription factors CREB-RP and OCT-1, and components of the ubiquitin pathway. Conclusions Our prediction method NetCorona predicts coronavirus cleavage sites with high specificity and several potential cleavage candidates were identified which might be important to elucidate coronavirus pathology. Furthermore, the method might assist in design of proteinase inhibitors for treatment of SARS and possible future diseases caused by coronaviruses. It is made available for public use at our website: http://www.cbs.dtu.dk/services/NetCorona/.

  14. Activity-dependent shedding of the NMDA receptor glycine binding site by matrix metalloproteinase 3: a PUTATIVE mechanism of postsynaptic plasticity.

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    Thorsten Pauly

    Full Text Available Functional and structural alterations of clustered postsynaptic ligand gated ion channels in neuronal cells are thought to contribute to synaptic plasticity and memory formation in the human brain. Here, we describe a novel molecular mechanism for structural alterations of NR1 subunits of the NMDA receptor. In cultured rat spinal cord neurons, chronic NMDA receptor stimulation induces disappearance of extracellular epitopes of NMDA receptor NR1 subunits, which was prevented by inhibiting matrix metalloproteinases (MMPs. Immunoblotting revealed the digestion of solubilized NR1 subunits by MMP-3 and identified a fragment of about 60 kDa as MMPs-activity-dependent cleavage product of the NR1 subunit in cultured neurons. The expression of MMP-3 in the spinal cord culture was shown by immunoblotting and immunofluorescence microscopy. Recombinant NR1 glycine binding protein was used to identify MMP-3 cleavage sites within the extracellular S1 and S2-domains. N-terminal sequencing and site-directed mutagenesis revealed S542 and L790 as two putative major MMP-3 cleavage sites of the NR1 subunit. In conclusion, our data indicate that MMPs, and in particular MMP-3, are involved in the activity dependent alteration of NMDA receptor structure at postsynaptic membrane specializations in the CNS.

  15. Activity-dependent shedding of the NMDA receptor glycine binding site by matrix metalloproteinase 3: a PUTATIVE mechanism of postsynaptic plasticity.

    Science.gov (United States)

    Pauly, Thorsten; Ratliff, Miriam; Pietrowski, Eweline; Neugebauer, Rainer; Schlicksupp, Andrea; Kirsch, Joachim; Kuhse, Jochen

    2008-07-16

    Functional and structural alterations of clustered postsynaptic ligand gated ion channels in neuronal cells are thought to contribute to synaptic plasticity and memory formation in the human brain. Here, we describe a novel molecular mechanism for structural alterations of NR1 subunits of the NMDA receptor. In cultured rat spinal cord neurons, chronic NMDA receptor stimulation induces disappearance of extracellular epitopes of NMDA receptor NR1 subunits, which was prevented by inhibiting matrix metalloproteinases (MMPs). Immunoblotting revealed the digestion of solubilized NR1 subunits by MMP-3 and identified a fragment of about 60 kDa as MMPs-activity-dependent cleavage product of the NR1 subunit in cultured neurons. The expression of MMP-3 in the spinal cord culture was shown by immunoblotting and immunofluorescence microscopy. Recombinant NR1 glycine binding protein was used to identify MMP-3 cleavage sites within the extracellular S1 and S2-domains. N-terminal sequencing and site-directed mutagenesis revealed S542 and L790 as two putative major MMP-3 cleavage sites of the NR1 subunit. In conclusion, our data indicate that MMPs, and in particular MMP-3, are involved in the activity dependent alteration of NMDA receptor structure at postsynaptic membrane specializations in the CNS.

  16. PROSPER: an integrated feature-based tool for predicting protease substrate cleavage sites.

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    Jiangning Song

    Full Text Available The ability to catalytically cleave protein substrates after synthesis is fundamental for all forms of life. Accordingly, site-specific proteolysis is one of the most important post-translational modifications. The key to understanding the physiological role of a protease is to identify its natural substrate(s. Knowledge of the substrate specificity of a protease can dramatically improve our ability to predict its target protein substrates, but this information must be utilized in an effective manner in order to efficiently identify protein substrates by in silico approaches. To address this problem, we present PROSPER, an integrated feature-based server for in silico identification of protease substrates and their cleavage sites for twenty-four different proteases. PROSPER utilizes established specificity information for these proteases (derived from the MEROPS database with a machine learning approach to predict protease cleavage sites by using different, but complementary sequence and structure characteristics. Features used by PROSPER include local amino acid sequence profile, predicted secondary structure, solvent accessibility and predicted native disorder. Thus, for proteases with known amino acid specificity, PROSPER provides a convenient, pre-prepared tool for use in identifying protein substrates for the enzymes. Systematic prediction analysis for the twenty-four proteases thus far included in the database revealed that the features we have included in the tool strongly improve performance in terms of cleavage site prediction, as evidenced by their contribution to performance improvement in terms of identifying known cleavage sites in substrates for these enzymes. In comparison with two state-of-the-art prediction tools, PoPS and SitePrediction, PROSPER achieves greater accuracy and coverage. To our knowledge, PROSPER is the first comprehensive server capable of predicting cleavage sites of multiple proteases within a single substrate

  17. Rendering one autolysis site in Bacillus subtilis neutral protease resistant to cleavage reveals a new fission

    NARCIS (Netherlands)

    Van den Burg, B; Eijsink, VGH; Vriend, G; Veltman, OR; Venema, G

    Autolytic degradation of the thermolysin-like proteinase of Bacillus subtilis (TLP-sub) is responsible for the irreversible inactivation of the enzyme at elevated temperatures. Previously we have reported five cleavage sites in Tip-sub [Van den Burg et al, (1990) Biochem. J. 272, 93-97]. In an

  18. Mapping of matrix metalloproteinase cleavage sites on syndecan-1 and syndecan-4 ectodomains

    DEFF Research Database (Denmark)

    Manon-Jensen, Tina; Multhaupt, Hinke A B; Couchman, John R

    2013-01-01

    Syndecans are transmembrane heparan sulfate proteoglycans with roles in cell proliferation, differentiation, adhesion, and migration. They have been associated with multiple functions in tumour progression, through their ability to interact with a wide range of ligands as well as other receptors,...

  19. Characterization of a Non-Canonical Signal Peptidase Cleavage Site in a Replication Protein from Tomato Ringspot Virus.

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    Ting Wei

    Full Text Available The NTB-VPg polyprotein from tomato ringspot virus is an integral membrane replication protein associated with endoplasmic reticulum membranes. A signal peptidase (SPase cleavage was previously detected in the C-terminal region of NTB-VPg downstream of a 14 amino acid (aa-long hydrophobic region (termed TM2. However, the exact location of the cleavage site was not determined. Using in vitro translation assays, we show that the SPase cleavage site is conserved in the NTB-VPg protein from various ToRSV isolates, although the rate of cleavage varies from one isolate to another. Systematic site-directed mutagenesis of the NTB-VPg SPase cleavage sites of two ToRSV isolates allowed the identification of sequences that affect cleavage efficiency. We also present evidence that SPase cleavage in the ToRSV-Rasp2 isolate occurs within a GAAGG sequence likely after the AAG (GAAG/G. Mutation of a downstream MAAV sequence to AAAV resulted in SPase cleavage at both the natural GAAG/G and the mutated AAA/V sequences. Given that there is a distance of seven aa between the two cleavage sites, this indicates that there is flexibility in the positioning of the cleavage sites relative to the inner surface of the membrane and the SPase active site. SPase cleavage sites are typically located 3-7 aa downstream of the hydrophobic region. However, the NTB-VPg GAAG/G cleavage site is located 17 aa downstream of the TM2 hydrophobic region, highlighting unusual features of the NTB-VPg SPase cleavage site. A putative 11 aa-long amphipathic helix was identified immediately downstream of the TM2 region and five aa upstream of the GAAG/G cleavage site. Based on these results, we present an updated topology model in which the hydrophobic and amphipathic domains form a long tilted helix or a bent helix in the membrane lipid bilayer, with the downstream cleavage site(s oriented parallel to the membrane inner surface.

  20. Hemoglobin cleavage site-specificity of the Plasmodium falciparum cysteine proteases falcipain-2 and falcipain-3.

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    Shoba Subramanian

    Full Text Available The Plasmodium falciparum cysteine proteases falcipain-2 and falcipain-3 degrade host hemoglobin to provide free amino acids for parasite protein synthesis. Hemoglobin hydrolysis has been described as an ordered process initiated by aspartic proteases, but cysteine protease inhibitors completely block the process, suggesting that cysteine proteases can also initiate hemoglobin hydrolysis. To characterize the specific roles of falcipains, we used three approaches. First, using random P(1 - P(4 amino acid substrate libraries, falcipain-2 and falcipain-3 demonstrated strong preference for cleavage sites with Leu at the P(2 position. Second, with overlapping peptides spanning alpha and beta globin and proteolysis-dependent (18O labeling, hydrolysis was seen at many cleavage sites. Third, with intact hemoglobin, numerous cleavage products were identified. Our results suggest that hemoglobin hydrolysis by malaria parasites is not a highly ordered process, but rather proceeds with rapid cleavage by falcipains at multiple sites. However, falcipain-2 and falcipain-3 show strong specificity for P(2 Leu in small peptide substrates, in agreement with the specificity in optimized small molecule inhibitors that was identified previously. These results are consistent with a principal role of falcipain-2 and falcipain-3 in the hydrolysis of hemoglobin by P. falciparum and with the possibility of developing small molecule inhibitors with optimized specificity as antimalarial agents.

  1. Signal peptide discrimination and cleavage site identification using SVM and NN.

    Science.gov (United States)

    Kazemian, H B; Yusuf, S A; White, K

    2014-02-01

    About 15% of all proteins in a genome contain a signal peptide (SP) sequence, at the N-terminus, that targets the protein to intracellular secretory pathways. Once the protein is targeted correctly in the cell, the SP is cleaved, releasing the mature protein. Accurate prediction of the presence of these short amino-acid SP chains is crucial for modelling the topology of membrane proteins, since SP sequences can be confused with transmembrane domains due to similar composition of hydrophobic amino acids. This paper presents a cascaded Support Vector Machine (SVM)-Neural Network (NN) classification methodology for SP discrimination and cleavage site identification. The proposed method utilises a dual phase classification approach using SVM as a primary classifier to discriminate SP sequences from Non-SP. The methodology further employs NNs to predict the most suitable cleavage site candidates. In phase one, a SVM classification utilises hydrophobic propensities as a primary feature vector extraction using symmetric sliding window amino-acid sequence analysis for discrimination of SP and Non-SP. In phase two, a NN classification uses asymmetric sliding window sequence analysis for prediction of cleavage site identification. The proposed SVM-NN method was tested using Uni-Prot non-redundant datasets of eukaryotic and prokaryotic proteins with SP and Non-SP N-termini. Computer simulation results demonstrate an overall accuracy of 0.90 for SP and Non-SP discrimination based on Matthews Correlation Coefficient (MCC) tests using SVM. For SP cleavage site prediction, the overall accuracy is 91.5% based on cross-validation tests using the novel SVM-NN model. © 2013 Published by Elsevier Ltd.

  2. Conservation of a proteinase cleavage site between an insect retrovirus (gypsy) Env protein and a baculovirus envelope fusion protein

    International Nuclear Information System (INIS)

    Pearson, Margot N.; Rohrmann, George F.

    2004-01-01

    The predicted Env protein of insect retroviruses (errantiviruses) is related to the envelope fusion protein of a major division of the Baculoviridae. The highest degree of homology is found in a region that contains a furin cleavage site in the baculovirus proteins and an adjacent sequence that has the properties of a fusion peptide. In this investigation, the homologous region in the Env protein of the gypsy retrovirus of Drosophila melanogaster (DmegypV) was investigated. Alteration of the predicted DmegypV Env proteinase cleavage site from RIAR to AIAR significantly reduced cleavage of Env in both Spodoptera frugiperda (Sf-9) and D. melanogaster (S2) cell lines. When the predicted DmegypV Env cleavage site RIAR was substituted for the cleavage sequence RRKR in the Lymantria dispar nucleopolyhedrovirus fusion protein (LD130) sequence, cleavage of the hybrid LD130 molecules still occurred, although at a reduced level. The conserved 21-amino acid sequence just downstream of the cleavage site, which is thought to be the fusion peptide in LD130, was also characterized. When this sequence from DmegypV Env was substituted for the homologous sequence in LD130, cleavage still occurred, but no fusion was observed in either cell type. In addition, although a DmegypV-Env-green fluorescent protein construct localized to cell membranes, no cell fusion was observed

  3. ADAM13 cleavage of cadherin-11 promotes CNC migration independently of the homophilic binding site.

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    Abbruzzese, Genevieve; Becker, Sarah F; Kashef, Jubin; Alfandari, Dominique

    2016-07-15

    The cranial neural crest (CNC) is a highly motile population of cells that is responsible for forming the face and jaw in all vertebrates and perturbing their migration can lead to craniofacial birth defects. Cell motility requires a dynamic modification of cell-cell and cell-matrix adhesion. In the CNC, cleavage of the cell adhesion molecule cadherin-11 by ADAM13 is essential for cell migration. This cleavage generates a shed extracellular fragment of cadherin-11 (EC1-3) that possesses pro-migratory activity via an unknown mechanism. Cadherin-11 plays an important role in modulating contact inhibition of locomotion (CIL) in the CNC to regulate directional cell migration. Here, we show that while the integral cadherin-11 requires the homophilic binding site to promote CNC migration in vivo, the EC1-3 fragment does not. In addition, we show that increased ADAM13 activity or expression of the EC1-3 fragment increases CNC invasiveness in vitro and blocks the repulsive CIL response in colliding cells. This activity requires the presence of an intact homophilic binding site on the EC1-3 suggesting that the cleavage fragment may function as a competitive inhibitor of cadherin-11 adhesion in CIL but not to promote cell migration in vivo. Copyright © 2015. Published by Elsevier Inc.

  4. Identification of succinimide sites in proteins by N-terminal sequence analysis after alkaline hydroxylamine cleavage.

    Science.gov (United States)

    Kwong, M. Y.; Harris, R. J.

    1994-01-01

    Under favorable conditions, Asp or Asn residues can undergo rearrangement to a succinimide (cyclic imide), which may also serve as an intermediate for deamidation and/or isoaspartate formation. Direct identification of such succinimides by peptide mapping is hampered by their lability at neutral and alkaline pH. We determined that incubation in 2 M hydroxylamine, 0.2 M Tris buffer, pH 9, for 2 h at 45 degrees C will specifically cleave on the C-terminal side of succinimides without cleavage at Asn-Gly bonds; yields are typically approximately 50%. N-terminal sequence analysis can then be used to identify an internal sequence generated by cleavage of the succinimide, hence identifying the succinimide site. PMID:8142891

  5. Mutation in Spike Protein Cleavage Site and Pathogenesis of Feline Coronavirus

    Science.gov (United States)

    Licitra, Beth N.; Millet, Jean K.; Regan, Andrew D.; Hamilton, Brian S.; Rinaldi, Vera D.; Duhamel, Gerald E.

    2013-01-01

    Feline coronaviruses (FCoV) exist as 2 biotypes: feline enteric coronavirus (FECV) and feline infectious peritonitis virus (FIPV). FECV causes subclinical infections; FIPV causes feline infectious peritonitis (FIP), a systemic and fatal disease. It is thought that mutations in FECV enable infection of macrophages, causing FIP. However, the molecular basis for this biotype switch is unknown. We examined a furin cleavage site in the region between receptor-binding (S1) and fusion (S2) domains of the spike of serotype 1 FCoV. FECV sequences were compared with FIPV sequences. All FECVs had a conserved furin cleavage motif. For FIPV, there was a correlation with the disease and >1 substitution in the S1/S2 motif. Fluorogenic peptide assays confirmed that the substitutions modulate furin cleavage. We document a functionally relevant S1/S2 mutation that arises when FIP develops in a cat. These insights into FIP pathogenesis may be useful in development of diagnostic, prevention, and treatment measures against coronaviruses. PMID:23763835

  6. Analysis of the Proteolytic Processing of ABCA3: Identification of Cleavage Site and Involved Proteases.

    Directory of Open Access Journals (Sweden)

    Nicole Hofmann

    Full Text Available ABCA3 is a lipid transporter in the limiting membrane of lamellar bodies in alveolar type II cells. Mutations in the ABCA3 gene cause respiratory distress syndrome in new-borns and childhood interstitial lung disease. ABCA3 is N-terminally cleaved by an as yet unknown protease, a process believed to regulate ABCA3 activity.The exact site where ABCA3 is cleaved was localized using mass spectrometry (MS. Proteases involved in ABCA3 processing were identified using small molecule inhibitors and siRNA mediated gene knockdown. Results were verified by in vitro digestion of a synthetic peptide substrate mimicking ABCA3's cleavage region, followed by MS analysis.We found that cleavage of ABCA3 occurs after Lys174 which is located in the proteins' first luminal loop. Inhibition of cathepsin L and, to a lesser extent, cathepsin B resulted in attenuation of ABCA3 cleavage. Both enzymes showed activity against the ABCA3 peptide in vitro with cathepsin L being more active.We show here that, like some other proteins of the lysosomal membrane, ABCA3 is a substrate of cathepsin L. Therefore, cathepsin L may represent a potential target to therapeutically influence ABCA3 activity in ABCA3-associated lung disease.

  7. Snake venom serine proteinases specificity mapping by proteomic identification of cleavage sites.

    Science.gov (United States)

    Zelanis, André; Huesgen, Pitter F; Oliveira, Ana Karina; Tashima, Alexandre K; Serrano, Solange M T; Overall, Christopher M

    2015-01-15

    Many snake venom toxins are serine proteases but their specific in vivo targets are mostly unknown. Various act on components of the coagulation cascade, and fibrinolytic and kallikrein-kinin systems to trigger various pathological effects observed in the envenomation. Despite showing high similarity in terms of primary structure snake venom serine proteinases (SVSPs) show exquisite specificity towards macromolecular substrates. Therefore, the characterization of their peptide bond specificity is important for understanding the active site preference associated with effective proteolysis as well as for the design of peptide substrates and inhibitors. Bothrops jararaca contains various SVSPs among which Bothrops protease A is a specific fibrinogenolytic agent and PA-BJ is a platelet-activating enzyme. In this study we used proteome derived peptide libraries in the Proteomic Identification of protease Cleavage Sites (PICS) approach to explore the peptide bond specificity of Bothrops protease A and PA-BJ in order to determine their individual peptide cleavage sequences. A total of 371 cleavage sites (208 for Bothrops protease A and 163 for PA-BJ) were detected and both proteinases displayed a clear preference for arginine at the P1 position. Moreover, the analysis of the specificity profiles of Bothrops protease A and PA-BJ revealed subtle differences in the preferences along P6-P6', despite a common yet unusual preference for Pro at P2. Taken together, these results map the subsite specificity of both SVSPs and shed light in the functional differences between these proteinases. Proteolysis is key to various pathological effects observed upon envenomation by viperid snakes. The use of the Proteomic Identification of protease Cleavage Sites (PICS) approach for the easy mapping of proteinase subsite preferences at both the prime- and non-prime sides concurrently gives rise to a fresh understanding of the interaction of the snake venom serine proteinases with peptide and

  8. Base substitutions at scissile bond sites are sufficient to alter RNA-binding and cleavage activity of RNase III.

    Science.gov (United States)

    Kim, Kyungsub; Sim, Se-Hoon; Jeon, Che Ok; Lee, Younghoon; Lee, Kangseok

    2011-02-01

    RNase III, a double-stranded RNA-specific endoribonuclease, degrades bdm mRNA via cleavage at specific sites. To better understand the mechanism of cleavage site selection by RNase III, we performed a genetic screen for sequences containing mutations at the bdm RNA cleavage sites that resulted in altered mRNA stability using a transcriptional bdm'-'cat fusion construct. While most of the isolated mutants showed the increased bdm'-'cat mRNA stability that resulted from the inability of RNase III to cleave the mutated sequences, one mutant sequence (wt-L) displayed in vivo RNA stability similar to that of the wild-type sequence. In vivo and in vitro analyses of the wt-L RNA substrate showed that it was cut only once on the RNA strand to the 5'-terminus by RNase III, while the binding constant of RNase III to this mutant substrate was moderately increased. A base substitution at the uncleaved RNase III cleavage site in wt-L mutant RNA found in another mutant lowered the RNA-binding affinity by 11-fold and abolished the hydrolysis of scissile bonds by RNase III. Our results show that base substitutions at sites forming the scissile bonds are sufficient to alter RNA cleavage as well as the binding activity of RNase III. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  9. Effects of mutations in the VP2/VP4 cleavage site of Swine vesicular disease virus on RNA encapsidation and viral infectivity

    NARCIS (Netherlands)

    Rebel, J.M.J.; Leendertse, C.H.; Dekker, A.; Moormann, R.J.M.

    2003-01-01

    We studied VP0 cleavage of Swine vesicular disease virus (SVDV), a member of the Picornaviridae using a full-length cDNA copy of the Dutch SVDV isolate. The influences of mutations, introduced at the cleavage site of SVDV, on VP0 cleavage, RNA encapsidation and viral infection were studied. Double

  10. ChloroP, a neural network-based method for predicting chloroplast transitpeptides and their cleavage sites

    DEFF Research Database (Denmark)

    Emanuelsson, O.; Nielsen, Henrik; von Heijne, Gunnar

    1999-01-01

    the cleavage sites given in SWISS-PROT. An analysis of 715 Arabidopsis thaliana sequences from SWISS-PROT suggests that the ChloroP method should be useful for the identification of putative transit peptides in genome-wide sequence data. The ChloroP predictor is available as a web-server at http......We present a neural network based method (ChloroP) for identifying chloroplast transit peptides and their cleavage sites. Using cross-validation, 88% of the sequences in our homology reduced training set were correctly classified as transit peptides or nontransit peptides. This performance level...

  11. Isolation of recombinant phage antibodies targeting the hemagglutinin cleavage site of highly pathogenic avian influenza virus.

    Directory of Open Access Journals (Sweden)

    Jinhua Dong

    Full Text Available Highly pathogenic avian influenza (HPAI H5N1 viruses, which have emerged in poultry and other wildlife worldwide, contain a characteristic multi-basic cleavage site (CS in the hemagglutinin protein (HA. Because this arginine-rich CS is unique among influenza virus subtypes, antibodies against this site have the potential to specifically diagnose pathogenic H5N1. By immunizing mice with the CS peptide and screening a phage display library, we isolated four antibody Fab fragment clones that specifically bind the antigen peptide and several HPAI H5N1 HA proteins in different clades. The soluble Fab fragments expressed in Escherichia coli bound the CS peptide and the H5N1 HA protein with nanomolar affinity. In an immunofluorescence assay, these Fab fragments stained cells infected with HPAI H5N1 but not those infected with a less virulent strain. Lastly, all the Fab clones could detect the CS peptide and H5N1 HA protein by open sandwich ELISA. Thus, these recombinant Fab fragments will be useful novel reagents for the rapid and specific detection of HPAI H5N1 virus.

  12. Model for how type I restriction enzymes select cleavage sites in DNA

    International Nuclear Information System (INIS)

    Studier, F.W.; Bandyopadhyay, P.K.

    1988-01-01

    Under appropriate conditions, digestion of phage T7 DNA by the type I restriction enzyme EcoK produces an orderly progression of discrete DNA fragments. All details of the fragmentation pattern can be explained on the basis of the known properties of type I enzymes, together with two further assumptions: (i) in the ATP-stimulated translocation reaction, the enzyme bound at the recognition sequence translocates DNA toward itself from both directions simultaneously; and (ii) when translocation causes neighboring enzymes to meet, they cut the DNA between them. The kinetics of digestion at 37 degree C indicates that the rate of translocation of DNA from each side of a bound enzyme is about 200 base pairs per second, and the cuts are completed within 15-25 sec of the time neighboring enzymes meet. The resulting DNA fragments each contain a single recognition site with an enzyme (or subunit) remaining bound to it. At high enzyme concentrations, such fragments can bu further degraded, apparently by cooperation between the specifically bound and excess enzymes. This model is consistent with a substantial body of previous work on the nuclease activity of EcoB and EcoK, and it explains in a simple way how cleavage sites are selected

  13. A neural network method for identification of prokaryotic and eukaryotic signal peptides and prediction of their cleavage sites

    DEFF Research Database (Denmark)

    Nielsen, Henrik; Engelbrecht, Jacob; Brunak, Søren

    1997-01-01

    We have developed a new method for the identication of signal peptides and their cleavage sites based on neural networks trained on separate sets of prokaryotic and eukaryotic sequences. The method performs signicantly better than previous prediction schemes, and can easily be applied to genome...

  14. Acquisition of a novel eleven amino acid insertion directly N-terminal to a tetrabasic cleavage site confers intracellular cleavage of an H7N7 influenza virus hemagglutinin

    International Nuclear Information System (INIS)

    Hamilton, Brian S.; Sun, Xiangjie; Chung, Changik; Whittaker, Gary R.

    2012-01-01

    A critical feature of highly pathogenic avian influenza viruses (H5N1 and H7N7) is the efficient intracellular cleavage of the hemagglutinin (HA) protein. H7N7 viruses also exist in equine species, and a unique feature of the equine H7N7 HA is the presence of an eleven amino acid insertion directly N-terminal to a tetrabasic cleavage site. Here, we show that three histidine residues within the unique insertion of the equine H7N7 HA are essential for intracellular cleavage. An asparagine residue within the insertion-derived glycosylation site was also found to be essential for intracellular cleavage. The presence of the histidine residues also appear to be involved in triggering fusion, since mutation of the histidine residues resulted in a destabilizing effect. Importantly, the addition of a tetrabasic site and the eleven amino acid insertion conferred efficient intracellular cleavage to the HA of an H7N3 low pathogenicity avian influenza virus. Our studies show that acquisition of the eleven amino acid insertion offers an alternative mechanism for intracellular cleavage of influenza HA.

  15. Acquisition of a novel eleven amino acid insertion directly N-terminal to a tetrabasic cleavage site confers intracellular cleavage of an H7N7 influenza virus hemagglutinin

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, Brian S.; Sun, Xiangjie; Chung, Changik [Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca NY 14853 (United States); New York Center of Excellence for Influenza Research and Surveillance, University of Rochester Medical Center, Rochester NY 14627 (United States); Whittaker, Gary R., E-mail: grw7@cornell.edu [Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca NY 14853 (United States); New York Center of Excellence for Influenza Research and Surveillance, University of Rochester Medical Center, Rochester NY 14627 (United States)

    2012-12-05

    A critical feature of highly pathogenic avian influenza viruses (H5N1 and H7N7) is the efficient intracellular cleavage of the hemagglutinin (HA) protein. H7N7 viruses also exist in equine species, and a unique feature of the equine H7N7 HA is the presence of an eleven amino acid insertion directly N-terminal to a tetrabasic cleavage site. Here, we show that three histidine residues within the unique insertion of the equine H7N7 HA are essential for intracellular cleavage. An asparagine residue within the insertion-derived glycosylation site was also found to be essential for intracellular cleavage. The presence of the histidine residues also appear to be involved in triggering fusion, since mutation of the histidine residues resulted in a destabilizing effect. Importantly, the addition of a tetrabasic site and the eleven amino acid insertion conferred efficient intracellular cleavage to the HA of an H7N3 low pathogenicity avian influenza virus. Our studies show that acquisition of the eleven amino acid insertion offers an alternative mechanism for intracellular cleavage of influenza HA.

  16. A camel-derived MERS-CoV with a variant spike protein cleavage site and distinct fusion activation properties

    Science.gov (United States)

    Millet, Jean Kaoru; Goldstein, Monty E; Labitt, Rachael N; Hsu, Hung-Lun; Daniel, Susan; Whittaker, Gary R

    2016-01-01

    Middle East respiratory syndrome coronavirus (MERS-CoV) continues to circulate in both humans and camels, and the origin and evolution of the virus remain unclear. Here we characterize the spike protein of a camel-derived MERS-CoV (NRCE-HKU205) identified in 2013, early in the MERS outbreak. NRCE-HKU205 spike protein has a variant cleavage motif with regard to the S2′ fusion activation site—notably, a novel substitution of isoleucine for the otherwise invariant serine at the critical P1′ cleavage site position. The substitutions resulted in a loss of furin-mediated cleavage, as shown by fluorogenic peptide cleavage and western blot assays. Cell–cell fusion and pseudotyped virus infectivity assays demonstrated that the S2′ substitutions decreased spike-mediated fusion and viral entry. However, cathepsin and trypsin-like protease activation were retained, albeit with much reduced efficiency compared with the prototypical EMC/2012 human strain. We show that NRCE-HKU205 has more limited fusion activation properties possibly resulting in more restricted viral tropism and may represent an intermediate in the complex pattern of MERS-CoV ecology and evolution. PMID:27999426

  17. Coronavirus 3CL(pro) proteinase cleavage sites: Possible relevance to SARS virus pathology

    DEFF Research Database (Denmark)

    Kiemer, Lars; Lund, Ole; Brunak, Søren

    2004-01-01

    the picornaviruses it is known that pathology is related to proteolytic cleavage of host proteins by viral proteinases. Furthermore, several studies indicate that virus proliferation can be arrested using specific proteinase inhibitors supporting the belief that proteinases are indeed important during infection...

  18. Identification of prokaryotic and eukaryotic signal peptides and prediction of their cleavage sites

    DEFF Research Database (Denmark)

    Nielsen, Henrik; Engelbrecht, Jacob; Brunak, Søren

    1997-01-01

    We have developed a new method for the identification of signal peptides and their cleavage based on neural networks trained on separate sets of prokaryotic and eukaryotic sequence. The method performs significantly better than previous prediction schemes and can easily be applied on genome...

  19. Sequence motif upstream of the Hendra virus fusion protein cleavage site is not sufficient to promote efficient proteolytic processing

    International Nuclear Information System (INIS)

    Craft, Willie Warren; Dutch, Rebecca Ellis

    2005-01-01

    The Hendra virus fusion (HeV F) protein is synthesized as a precursor, F 0 , and proteolytically cleaved into the mature F 1 and F 2 heterodimer, following an HDLVDGVK 109 motif. This cleavage event is required for fusogenic activity. To determine the amino acid requirements for processing of the HeV F protein, we constructed multiple mutants. Individual and simultaneous alanine substitutions of the eight residues immediately upstream of the cleavage site did not eliminate processing. A chimeric SV5 F protein in which the furin site was substituted for the VDGVK 109 motif of the HeV F protein was not processed but was expressed on the cell surface. Another chimeric SV5 F protein containing the HDLVDGVK 109 motif of the HeV F protein underwent partial cleavage. These data indicate that the upstream region can play a role in protease recognition, but is neither absolutely required nor sufficient for efficient processing of the HeV F protein

  20. Molecular pathogenesis of H5 highly pathogenic avian influenza: the role of the haemagglutinin cleavage site motif

    Science.gov (United States)

    Luczo, Jasmina M.; Stambas, John; Durr, Peter A.; Michalski, Wojtek P.

    2015-01-01

    Summary The emergence of H5N1 highly pathogenic avian influenza has caused a heavy socio‐economic burden through culling of poultry to minimise human and livestock infection. Although human infections with H5N1 have to date been limited, concerns for the pandemic potential of this zoonotic virus have been greatly intensified following experimental evidence of aerosol transmission of H5N1 viruses in a mammalian infection model. In this review, we discuss the dominance of the haemagglutinin cleavage site motif as a pathogenicity determinant, the host‐pathogen molecular interactions driving cleavage activation, reverse genetics manipulations and identification of residues key to haemagglutinin cleavage site functionality and the mechanisms of cell and tissue damage during H5N1 infection. We specifically focus on the disease in chickens, as it is in this species that high pathogenicity frequently evolves and from which transmission to the human population occurs. With >75% of emerging infectious diseases being of zoonotic origin, it is necessary to understand pathogenesis in the primary host to explain spillover events into the human population. © 2015 The Authors. Reviews in Medical Virology published by John Wiley & Sons Ltd. PMID:26467906

  1. Action of matrix metalloproteinases at restricted sites in colon anastomosis repair

    DEFF Research Database (Denmark)

    Ågran, Magnus S.; Levin Andersen, Thomas; Mirastschijski, Ursula

    2006-01-01

    compared with adjacent micro-areas of 3-day-old anastomoses. Only this specific tissue compartment underwent a dramatic and significant increase in collagenolysis, amounting to a loss of 10% of existing collagen molecules in 24 hours, and was abolished by metalloproteinase inhibitors. The tissue....... CONCLUSIONS: The unique finding of this study was that the specific tissue holding the sutures of a colon anastomosis lost the most collagen presumably through induction and activation of multiple MMPs that may explain the beneficial effects of treatment with non-selective MMP antagonists....

  2. Identification of E-cadherin signature motifs functioning as cleavage sites for Helicobacter pylori HtrA

    Science.gov (United States)

    Schmidt, Thomas P.; Perna, Anna M.; Fugmann, Tim; Böhm, Manja; Jan Hiss; Haller, Sarah; Götz, Camilla; Tegtmeyer, Nicole; Hoy, Benjamin; Rau, Tilman T.; Neri, Dario; Backert, Steffen; Schneider, Gisbert; Wessler, Silja

    2016-03-01

    The cell adhesion protein and tumour suppressor E-cadherin exhibits important functions in the prevention of gastric cancer. As a class-I carcinogen, Helicobacter pylori (H. pylori) has developed a unique strategy to interfere with E-cadherin functions. In previous studies, we have demonstrated that H. pylori secretes the protease high temperature requirement A (HtrA) which cleaves off the E-cadherin ectodomain (NTF) on epithelial cells. This opens cell-to-cell junctions, allowing bacterial transmigration across the polarised epithelium. Here, we investigated the molecular mechanism of the HtrA-E-cadherin interaction and identified E-cadherin cleavage sites for HtrA. Mass-spectrometry-based proteomics and Edman degradation revealed three signature motifs containing the [VITA]-[VITA]-x-x-D-[DN] sequence pattern, which were preferentially cleaved by HtrA. Based on these sites, we developed a substrate-derived peptide inhibitor that selectively bound and inhibited HtrA, thereby blocking transmigration of H. pylori. The discovery of HtrA-targeted signature sites might further explain why we detected a stable 90 kDa NTF fragment during H. pylori infection, but also additional E-cadherin fragments ranging from 105 kDa to 48 kDa in in vitro cleavage experiments. In conclusion, HtrA targets E-cadherin signature sites that are accessible in in vitro reactions, but might be partially masked on epithelial cells through functional homophilic E-cadherin interactions.

  3. Positioning the 5'-flap junction in the active site controls the rate of flap endonuclease-1-catalyzed DNA cleavage

    KAUST Repository

    Song, Bo

    2018-02-09

    Flap endonucleases catalyze cleavage of single-stranded DNA flaps formed during replication, repair and recombination, and are therefore essential for genome processing and stability. Recent crystal structures of DNA-bound human flap endonuclease (hFEN1) offer new insights into how conformational changes in the DNA and hFEN1 may facilitate the reaction mechanism. For example, previous biochemical studies of DNA conformation performed under non-catalytic conditions with Ca2+ have suggested that base unpairing at the 5\\'-flap:template junction is an important step in the reaction, but the new structural data suggest otherwise. To clarify the role of DNA changes in the kinetic mechanism, we measured a series of transient steps - from substrate binding to product release - during the hFEN1-catalyzed reaction in the presence of Mg2+. We found that while hFEN1 binds and bends DNA at a fast, diffusion-limited rate, much slower Mg2+-dependent conformational changes in DNA around the active site are subsequently necessary and rate-limiting for 5\\'-flap cleavage. These changes are reported overall by fluorescence of 2-aminopurine at the 5\\'-flap:template junction, indicating that local DNA distortion (e.g., disruption of base stacking observed in structures), associated with positioning the 5\\'-flap scissile phosphodiester bond in the hFEN1 active site, controls catalysis. hFEN1 residues with distinct roles in the catalytic mechanism, including those binding metal ions (Asp-34, Asp-181), steering the 5\\'-flap through the active site and binding the scissile phosphate (Lys-93, Arg-100), and stacking against the base 5\\' to the scissile phosphate (Tyr-40), all contribute to these rate-limiting conformational changes, ensuring efficient and specific cleavage of 5\\'-flaps.

  4. Positioning the 5'-flap junction in the active site controls the rate of flap endonuclease-1-catalyzed DNA cleavage

    KAUST Repository

    Song, Bo; Hamdan, Samir; Hingorani, Manju M

    2018-01-01

    Flap endonucleases catalyze cleavage of single-stranded DNA flaps formed during replication, repair and recombination, and are therefore essential for genome processing and stability. Recent crystal structures of DNA-bound human flap endonuclease (hFEN1) offer new insights into how conformational changes in the DNA and hFEN1 may facilitate the reaction mechanism. For example, previous biochemical studies of DNA conformation performed under non-catalytic conditions with Ca2+ have suggested that base unpairing at the 5'-flap:template junction is an important step in the reaction, but the new structural data suggest otherwise. To clarify the role of DNA changes in the kinetic mechanism, we measured a series of transient steps - from substrate binding to product release - during the hFEN1-catalyzed reaction in the presence of Mg2+. We found that while hFEN1 binds and bends DNA at a fast, diffusion-limited rate, much slower Mg2+-dependent conformational changes in DNA around the active site are subsequently necessary and rate-limiting for 5'-flap cleavage. These changes are reported overall by fluorescence of 2-aminopurine at the 5'-flap:template junction, indicating that local DNA distortion (e.g., disruption of base stacking observed in structures), associated with positioning the 5'-flap scissile phosphodiester bond in the hFEN1 active site, controls catalysis. hFEN1 residues with distinct roles in the catalytic mechanism, including those binding metal ions (Asp-34, Asp-181), steering the 5'-flap through the active site and binding the scissile phosphate (Lys-93, Arg-100), and stacking against the base 5' to the scissile phosphate (Tyr-40), all contribute to these rate-limiting conformational changes, ensuring efficient and specific cleavage of 5'-flaps.

  5. The prototype HIV-1 maturation inhibitor, bevirimat, binds to the CA-SP1 cleavage site in immature Gag particles

    Directory of Open Access Journals (Sweden)

    Nguyen Albert T

    2011-12-01

    Full Text Available Abstract Background Bevirimat, the prototype Human Immunodeficiency Virus type 1 (HIV-1 maturation inhibitor, is highly potent in cell culture and efficacious in HIV-1 infected patients. In contrast to inhibitors that target the active site of the viral protease, bevirimat specifically inhibits a single cleavage event, the final processing step for the Gag precursor where p25 (CA-SP1 is cleaved to p24 (CA and SP1. Results In this study, photoaffinity analogs of bevirimat and mass spectrometry were employed to map the binding site of bevirimat to Gag within immature virus-like particles. Bevirimat analogs were found to crosslink to sequences overlapping, or proximal to, the CA-SP1 cleavage site, consistent with previous biochemical data on the effect of bevirimat on Gag processing and with genetic data from resistance mutations, in a region predicted by NMR and mutational studies to have α-helical character. Unexpectedly, a second region of interaction was found within the Major Homology Region (MHR. Extensive prior genetic evidence suggests that the MHR is critical for virus assembly. Conclusions This is the first demonstration of a direct interaction between the maturation inhibitor, bevirimat, and its target, Gag. Information gained from this study sheds light on the mechanisms by which the virus develops resistance to this class of drug and may aid in the design of next-generation maturation inhibitors.

  6. Cleavage sites in the polypeptide precursors of poliovirus protein P2-X

    International Nuclear Information System (INIS)

    Selmer, B.L.; Hanecak, R.; Anderson, C.W.; Wimmer, E.

    1981-01-01

    Partial amino-terminal sequence analysis has been performed on the three major polypeptide products (P2-3b, P2-5b, and P2-X) from the central region (P2) of the poliovirus polyprotein, and this analysis precisely locates the amino termini of these products with respect to the nucleotide sequence of the poliovirus RNA genome. Like most of the products of the replicase region (P3), the amino termini of P2-5b and P2-X are generated by cleavage between glutamine and glycine residues. Thus, P2-5b and P2-X are probably both produced by the action of a singly (virus-encoded.) proteinase. The amino terminus of P2-3b, on the other hand, is produced by a cleavage between the carboxy-terminal tyrosine of VP1 and the glycine encoded by nucleotides 3381-3383. This result may suggest that more than one proteolytic activity is required for the complete processing of the poliovirus polyprotein

  7. SVM-based prediction of propeptide cleavage sites in spider toxins identifies toxin innovation in an Australian tarantula.

    Directory of Open Access Journals (Sweden)

    Emily S W Wong

    Full Text Available Spider neurotoxins are commonly used as pharmacological tools and are a popular source of novel compounds with therapeutic and agrochemical potential. Since venom peptides are inherently toxic, the host spider must employ strategies to avoid adverse effects prior to venom use. It is partly for this reason that most spider toxins encode a protective proregion that upon enzymatic cleavage is excised from the mature peptide. In order to identify the mature toxin sequence directly from toxin transcripts, without resorting to protein sequencing, the propeptide cleavage site in the toxin precursor must be predicted bioinformatically. We evaluated different machine learning strategies (support vector machines, hidden Markov model and decision tree and developed an algorithm (SpiderP for prediction of propeptide cleavage sites in spider toxins. Our strategy uses a support vector machine (SVM framework that combines both local and global sequence information. Our method is superior or comparable to current tools for prediction of propeptide sequences in spider toxins. Evaluation of the SVM method on an independent test set of known toxin sequences yielded 96% sensitivity and 100% specificity. Furthermore, we sequenced five novel peptides (not used to train the final predictor from the venom of the Australian tarantula Selenotypus plumipes to test the accuracy of the predictor and found 80% sensitivity and 99.6% 8-mer specificity. Finally, we used the predictor together with homology information to predict and characterize seven groups of novel toxins from the deeply sequenced venom gland transcriptome of S. plumipes, which revealed structural complexity and innovations in the evolution of the toxins. The precursor prediction tool (SpiderP is freely available on ArachnoServer (http://www.arachnoserver.org/spiderP.html, a web portal to a comprehensive relational database of spider toxins. All training data, test data, and scripts used are available from

  8. The Conserved ATM Kinase RAG2-S365 Phosphorylation Site Limits Cleavage Events in Individual Cells Independent of Any Repair Defect

    Directory of Open Access Journals (Sweden)

    Susannah L. Hewitt

    2017-10-01

    Full Text Available Many DNA lesions associated with lymphoid malignancies are linked to off-target cleavage by the RAG1/2 recombinase. However, off-target cleavage has mostly been analyzed in the context of DNA repair defects, confounding any mechanistic understanding of cleavage deregulation. We identified a conserved SQ phosphorylation site on RAG2 365 to 366 that is involved in feedback control of RAG cleavage. Mutation of serine 365 to a non-phosphorylatable alanine permits bi-allelic and bi-locus RAG-mediated breaks in the same cell, leading to reciprocal translocations. This phenomenon is analogous to the phenotype we described for ATM kinase inactivation. Here, we establish deregulated cleavage itself as a driver of chromosomal instability without the associated repair defect. Intriguingly, a RAG2-S365E phosphomimetic rescues the deregulated cleavage of ATM inactivation, reducing the incidence of reciprocal translocations. These data support a model in which feedback control of cleavage and maintenance of genome stability involves ATM-mediated phosphorylation of RAG2.

  9. Factor VIII S373L: mutation at P1' site confers thrombin cleavage resistance, causing mild haemophilia A.

    Science.gov (United States)

    Johnson, D J; Pemberton, S; Acquila, M; Mori, P G; Tuddenham, E G; O'Brien, D P

    1994-04-01

    A novel CRM+ mutation, factor VIII position 373 serine to leucine substitution (FVIII 373-Leu) was identified during a survey of Factor VIII (FVIII) mutations. We have purified the variant protein from the patient's plasma in order to allow further characterisation of the molecule. The CRM+ plasma contained 120% Factor VIII antigen (FVIII:Ag) and 6% Factor VIII coagulant activity (FVIII:C). After purification the mutant FVIII was subjected to thrombin proteolysis, and was thereby activated 5.6-fold compared with 7-fold for wild type molecule. Subsequently, spontaneous inactivation of the mutant was much slower than noted for wild type FVIII. Western blot analysis using monoclonal antibodies demonstrated that thrombin cleavage of FVIII 373-Leu at positions 740 and 1689 were normal but that cleavage at position 372 was completely absent. Crystallographic coordinates of the active site of thrombin complexed to fibrinopeptide A were used to explore possible mechanistic reasons for the failure of thrombin to cleave the mutant FVIII at position 372. Steric hindrance between the mutant side chain and the side chain of the P1 residue was apparent. We conclude that the functional defect of FVIII 373-Leu results from the inability of thrombin to cleave the mutant at position 372-373, and propose that this is due to steric hindrance by the side chain of leucine 373, preventing correct formation of the enzyme substrate complex.

  10. Functional role of proteolytic cleavage at arginine-275 of human tissue plasminogen activator as assessed by site-directed mutagenesis

    International Nuclear Information System (INIS)

    Tate, K.M.; Higgins, D.L.; Holmes, W.E.; Winkler, M.E.; Heyneker, H.L.; Vehar, G.A.

    1987-01-01

    Activation of the zymogen form of a serine protease is associated with a conformational change that follows proteolysis at a specific site. Tissue-type plasminogen activator (t-PA) is homologous to mammalian serine proteases and contains an apparent activation cleavage site at arginine-275. To clarify the functional consequences of cleavage at arginine-275 of t-PA, site-specific mutagenesis was performed to convert arginine-275 to a glutamic acid. The mutant enzyme (designated Arg-275 → Glu t-PA) could be converted to the two-chain form by Staphylococcus aureus V8 protease but not by plasmin. The one-chain form was 8 times less active against the tripeptide substrate H-D-isoleucyl-L-prolyl-L-arginine-rho-nitroanilide (S-2288), and the ability of the enzyme to activate plasminogen in the absence of fibrinogen was reduced 20-50 times compared to the two-chain form. In contrast, one-chain Arg-275 → Glu t-PA has equal activity to the two-chain form when assayed in the presence of physiological levels of fibrinogen and plasminogen. Fibrin bound significantly more of the one-chain form of t-PA than the two-chain form for both the wild-type and mutated enzymes. One- and two-chain forms of the wild-type and mutated plasminogen activators slowly formed complexes with plasma protease inhibitors, although the one-chain forms showed decreased complex formation with → 2 -macroglobulin. The one-chain form of t-PA therefore is fully functional under physiologic conditions and has a increased fibrin binding compared to the two-chain form

  11. A Molecular Sensor To Characterize Arenavirus Envelope Glycoprotein Cleavage by Subtilisin Kexin Isozyme 1/Site 1 Protease

    Science.gov (United States)

    Oppliger, Joel; da Palma, Joel Ramos; Burri, Dominique J.; Khatib, Abdel-Majid; Spiropoulou, Christina F.

    2015-01-01

    ABSTRACT Arenaviruses are emerging viruses including several causative agents of severe hemorrhagic fevers in humans. The advent of next-generation sequencing technology has greatly accelerated the discovery of novel arenavirus species. However, for many of these viruses, only genetic information is available, and their zoonotic disease potential remains unknown. During the arenavirus life cycle, processing of the viral envelope glycoprotein precursor (GPC) by the cellular subtilisin kexin isozyme 1 (SKI-1)/site 1 protease (S1P) is crucial for productive infection. The ability of newly emerging arenaviruses to hijack human SKI-1/S1P appears, therefore, to be a requirement for efficient zoonotic transmission and human disease potential. Here we implement a newly developed cell-based molecular sensor for SKI-1/S1P to characterize the processing of arenavirus GPC-derived target sequences by human SKI-1/S1P in a quantitative manner. We show that only nine amino acids flanking the putative cleavage site are necessary and sufficient to accurately recapitulate the efficiency and subcellular location of arenavirus GPC processing. In a proof of concept, our sensor correctly predicts efficient processing of the GPC of the newly emergent pathogenic Lujo virus by human SKI-1/S1P and defines the exact cleavage site. Lastly, we employed our sensor to show efficient GPC processing of a panel of pathogenic and nonpathogenic New World arenaviruses, suggesting that GPC cleavage represents no barrier for zoonotic transmission of these pathogens. Our SKI-1/S1P sensor thus represents a rapid and robust test system for assessment of the processing of putative cleavage sites derived from the GPCs of newly discovered arenavirus by the SKI-1/S1P of humans or any other species, based solely on sequence information. IMPORTANCE Arenaviruses are important emerging human pathogens that can cause severe hemorrhagic fevers with high mortality in humans. A crucial step in productive arenavirus

  12. Two tandem RNase III cleavage sites determine betT mRNA stability in response to osmotic stress in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Minji Sim

    Full Text Available While identifying genes regulated by ribonuclease III (RNase III in Escherichia coli, we observed that steady-state levels of betT mRNA, which encodes a transporter mediating the influx of choline, are dependent on cellular concentrations of RNase III. In the present study, we also observed that steady-state levels of betT mRNA are dependent on RNase III activity upon exposure to osmotic stress, indicating the presence of cis-acting elements controlled by RNase III in betT mRNA. Primer extension analyses of betT mRNA revealed two tandem RNase III cleavage sites in its stem-loop region, which were biochemically confirmed via in vitro cleavage assays. Analyses of cleavage sites suggested the stochastic selection of cleavage sites by RNase III, and mutational analyses indicated that RNase III cleavage at either site individually is insufficient for efficient betT mRNA degradation. In addition, both the half-life and abundance of betT mRNA were significantly increased in association with decreased RNase III activity under hyper-osmotic stress conditions. Our findings demonstrate that betT mRNA stability is controlled by RNase III at the post-transcriptional level under conditions of osmotic stress.

  13. Identification of the protease cleavage sites in a reconstituted Gag polyprotein of an HERV-K(HML-2 element

    Directory of Open Access Journals (Sweden)

    Kurth Reinhard

    2011-05-01

    Full Text Available Abstract Background The human genome harbors several largely preserved HERV-K(HML-2 elements. Although this retroviral family comes closest of all known HERVs to producing replication competent virions, mutations acquired during their chromosomal residence have rendered them incapable of expressing infectious particles. This also holds true for the HERV-K113 element that has conserved open reading frames (ORFs for all its proteins in addition to a functional LTR promoter. Uncertainty concerning the localization and impact of post-insertional mutations has greatly hampered the functional characterization of these ancient retroviruses and their proteins. However, analogous to other betaretroviruses, it is known that HERV-K(HML-2 virions undergo a maturation process during or shortly after release from the host cell. During this process, the subdomains of the Gag polyproteins are released by proteolytic cleavage, although the nature of the mature HERV-K(HML-2 Gag proteins and the exact position of the cleavage sites have until now remained unknown. Results By aligning the amino acid sequences encoded by the gag-pro-pol ORFs of HERV-K113 with the corresponding segments from 10 other well-preserved human specific elements we identified non-synonymous post-insertional mutations that have occurred in this region of the provirus. Reversion of these mutations and a partial codon optimization facilitated the large-scale production of maturation-competent HERV-K113 virus-like particles (VLPs. The Gag subdomains of purified mature VLPs were separated by reversed-phase high-pressure liquid chromatography and initially characterized using specific antibodies. Cleavage sites were identified by mass spectrometry and N-terminal sequencing and confirmed by mutagenesis. Our results indicate that the gag gene product Pr74Gag of HERV-K(HML-2 is processed to yield p15-MA (matrix, SP1 (spacer peptide of 14 amino acids, p15, p27-CA (capsid, p10-NC (nucleocapsid and two

  14. Identification of the protease cleavage sites in a reconstituted Gag polyprotein of an HERV-K(HML-2) element.

    Science.gov (United States)

    George, Maja; Schwecke, Torsten; Beimforde, Nadine; Hohn, Oliver; Chudak, Claudia; Zimmermann, Anja; Kurth, Reinhard; Naumann, Dieter; Bannert, Norbert

    2011-05-09

    The human genome harbors several largely preserved HERV-K(HML-2) elements. Although this retroviral family comes closest of all known HERVs to producing replication competent virions, mutations acquired during their chromosomal residence have rendered them incapable of expressing infectious particles. This also holds true for the HERV-K113 element that has conserved open reading frames (ORFs) for all its proteins in addition to a functional LTR promoter. Uncertainty concerning the localization and impact of post-insertional mutations has greatly hampered the functional characterization of these ancient retroviruses and their proteins. However, analogous to other betaretroviruses, it is known that HERV-K(HML-2) virions undergo a maturation process during or shortly after release from the host cell. During this process, the subdomains of the Gag polyproteins are released by proteolytic cleavage, although the nature of the mature HERV-K(HML-2) Gag proteins and the exact position of the cleavage sites have until now remained unknown. By aligning the amino acid sequences encoded by the gag-pro-pol ORFs of HERV-K113 with the corresponding segments from 10 other well-preserved human specific elements we identified non-synonymous post-insertional mutations that have occurred in this region of the provirus. Reversion of these mutations and a partial codon optimization facilitated the large-scale production of maturation-competent HERV-K113 virus-like particles (VLPs). The Gag subdomains of purified mature VLPs were separated by reversed-phase high-pressure liquid chromatography and initially characterized using specific antibodies. Cleavage sites were identified by mass spectrometry and N-terminal sequencing and confirmed by mutagenesis. Our results indicate that the gag gene product Pr74Gag of HERV-K(HML-2) is processed to yield p15-MA (matrix), SP1 (spacer peptide of 14 amino acids), p15, p27-CA (capsid), p10-NC (nucleocapsid) and two C-terminally encoded glutamine- and

  15. A novel functional site of extracellular matrix metalloproteinase inducer (EMMPRIN) that limits the migration of human uterine cervical carcinoma cells.

    Science.gov (United States)

    Sato, Takashi; Watanabe, Mami; Hashimoto, Kei; Ota, Tomoko; Akimoto, Noriko; Imada, Keisuke; Nomizu, Motoyoshi; Ito, Akira

    2012-01-01

    EMMPRIN (extracellular matrix metalloproteinase inducer)/CD147, a membrane-bound glycoprotein with two extracellular loop domains (termed loops I and II), progresses tumor invasion and metastasis by increasing the production of matrix metalloproteinase (MMP) in peritumoral stoma cells. EMMPRIN has also been associated with the control of migration activity in some tumor cells, but little is known about how EMMPRIN regulates tumor cell migration. In the present study, EMMPRIN siRNA suppressed the gene expression and production of EMMPRIN in human uterine cervical carcinoma SKG-II cells. An in vitro scratch wound assay showed enhancement of migration of EMMPRIN-knockdown SKG-II cells. In addition, the SKG-II cell migration was augmented by adding an E. coli-expressed human EMMPRIN mutant with two extracellular loop domains (eEMP-I/II), which bound to the cell surface of SKG-II cells. However, eEMP-I/II suppressed the native EMMPRIN-mediated augmentation of proMMP-1/procollagenase-1 production in a co-culture of the SKG-II cells and human uterine cervical fibroblasts, indicating that the augmentation of SKG-II cell migration resulted from the interference of native EMMPRIN functions by eEMP-I/II on the cell surface. Furthermore, a systematic peptide screening method using nine synthetic EMMPRIN peptides coding the loop I and II domains (termed EM1-9) revealed that EM9 (170HIENLNMEADPGQYR184) facilitated SKG-II cell migration. Moreover, SKG-II cell migration was enhanced by administration of an antibody against EM9, but not EM1 which is a crucial site for the MMP inducible activity of EMMPRIN. Therefore, these results provide novel evidence that EMMPRIN on the cell surface limits the cell migration of human uterine cervical carcinoma cells through 170HIENLNMEADPGQYR184 in the loop II domain. Finally, these results should provide an increased understanding of the functions of EMMPRIN in malignant cervical carcinoma cells, and could contribute to the development of

  16. Identification of Cleavage Sites Recognized by the 3C-Like Cysteine Protease within the Two Polyproteins of Strawberry Mottle Virus

    Directory of Open Access Journals (Sweden)

    Hélène Sanfaçon

    2017-04-01

    Full Text Available Strawberry mottle virus (SMoV, family Secoviridae, order Picornavirales is one of several viruses found in association with strawberry decline disease in Eastern Canada. The SMoV genome consists of two positive-sense single-stranded RNAs, each encoding one large polyprotein. The RNA1 polyprotein (P1 includes the domains for a putative helicase, a VPg, a 3C-like cysteine protease and an RNA-dependent RNA polymerase at its C-terminus, and one or two protein domains at its N-terminus. The RNA2 polyprotein (P2 is predicted to contain the domains for a movement protein (MP and one or several coat proteins at its N-terminus, and one or more additional domains for proteins of unknown function at its C-terminus. The RNA1-encoded 3C-like protease is presumed to cleave the two polyproteins in cis (P1 and in trans (P2. Using in vitro processing assays, we systematically scanned the two polyproteins for cleavage sites recognized by this protease. We identified five cis-cleavage sites in P1, with cleavage between the putative helicase and VPg domains being the most efficient. The presence of six protein domains in the SMoV P1, including two upstream of the putative helicase domain, is a feature shared with nepoviruses but not with comoviruses. Results from trans-cleavage assays indicate that the RNA1-encoded 3C-like protease recognized a single cleavage site, which was between the predicted MP and coat protein domains in the P2 polyprotein. The cleavage site consensus sequence for the SMoV 3C-like protease is AxE (E or Q/(G or S.

  17. Defining a similarity threshold for a functional proteinsequence pattern: The signal peptide cleavage site

    DEFF Research Database (Denmark)

    Nielsen, Henrik; Engelbrecht, Jacob; von Heijne, Gunnar

    1996-01-01

    When preparing data sets of amino acid or nucleotide sequences it is necessary to exclude redundant or homologous sequences in order to avoid overestimating the predictive performance of an algorithm. For some time methods for doing this have been available in the area of protein structure...... prediction. We have developed a similar procedure based on pair-wise alignments for sequences with functional sites. We show how a correlation coefficient between sequence similarity and functional homology can be used to compare the efficiency of different similarity measures and choose a nonarbitrary...

  18. A consistency-based feature selection method allied with linear SVMs for HIV-1 protease cleavage site prediction.

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    Orkun Oztürk

    Full Text Available BACKGROUND: Predicting type-1 Human Immunodeficiency Virus (HIV-1 protease cleavage site in protein molecules and determining its specificity is an important task which has attracted considerable attention in the research community. Achievements in this area are expected to result in effective drug design (especially for HIV-1 protease inhibitors against this life-threatening virus. However, some drawbacks (like the shortage of the available training data and the high dimensionality of the feature space turn this task into a difficult classification problem. Thus, various machine learning techniques, and specifically several classification methods have been proposed in order to increase the accuracy of the classification model. In addition, for several classification problems, which are characterized by having few samples and many features, selecting the most relevant features is a major factor for increasing classification accuracy. RESULTS: We propose for HIV-1 data a consistency-based feature selection approach in conjunction with recursive feature elimination of support vector machines (SVMs. We used various classifiers for evaluating the results obtained from the feature selection process. We further demonstrated the effectiveness of our proposed method by comparing it with a state-of-the-art feature selection method applied on HIV-1 data, and we evaluated the reported results based on attributes which have been selected from different combinations. CONCLUSION: Applying feature selection on training data before realizing the classification task seems to be a reasonable data-mining process when working with types of data similar to HIV-1. On HIV-1 data, some feature selection or extraction operations in conjunction with different classifiers have been tested and noteworthy outcomes have been reported. These facts motivate for the work presented in this paper. SOFTWARE AVAILABILITY: The software is available at http

  19. The Role of G-Protein-Coupled Receptor Proteolysis Site Cleavage of Polycystin-1 in Renal Physiology and Polycystic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Marie Trudel

    2016-01-01

    Full Text Available Polycystin-1 (PC1 plays an essential role in renal tubular morphogenesis, and PC1 dysfunction causes human autosomal dominant polycystic kidney disease. A fundamental characteristic of PC1 is post-translational modification via cleavage at the juxtamembrane GPCR proteolysis site (GPS motif that is part of the larger GAIN domain. Given the considerable biochemical complexity of PC1 molecules generated in vivo by this process, GPS cleavage has several profound implications on the intracellular trafficking and localization in association with their particular function. The critical nature of GPS cleavage is further emphasized by the increasing numbers of PKD1 mutations that significantly affect this cleavage process. The GAIN domain with the GPS motif therefore represents the key structural element with fundamental importance for PC1 and might be polycystic kidney disease’s (PKD Achilles’ heel in a large spectrum of PKD1 missense mutations. We highlight the central roles of PC1 cleavage for the regulation of its biogenesis, intracellular trafficking and function, as well as its significance in polycystic kidney disease.

  20. A catalytic metal ion interacts with the cleavage site G•U wobble in the HDV ribozyme†

    Science.gov (United States)

    Chen, Jui-Hui; Gong, Bo; Bevilacqua, Philip C.; Carey, Paul R.; Golden, Barbara L.

    2009-01-01

    The HDV ribozyme self-cleaves by a chemical mechanism involving general acid-base catalysis to generate a 2′,3′-cyclic phosphate and a 5′-hydroxyl termini. Biochemical studies from several laboratories have implicated C75 as the general acid and hydrated magnesium as the general base. We have previously shown that C75 has a pKa shifted > 2 pH units toward neutrality [Gong, B., Chen, J. H., Chase, E., Chadalavada, D. M., Yajima, R., Golden, B. L., Bevilacqua, P. C., and Carey, P. R. (2007) J. Am. Chem. Soc. 129, 13335–13342.], while in crystal structures, it is well-positioned for proton transfer. However no crystallographic evidence for a hydrated magnesium poised to serve as a general base in the reaction has been observed in high-resolution crystal structures of various reaction states and mutants. Herein, we use solution kinetic experiments and parallel Raman crystallographic studies to examine the effects of pH on rate and Mg2+-binding properties of wild-type and 7-deazaguanosine mutants of the HDV ribozyme. These data suggest that a previously-unobserved hydrated magnesium ion interacts with the N7 of the cleavage site G•U wobble base pair. Integrating this metal ion binding site with the available crystal structures provides a new three-dimensional model for the active site of the ribozyme that accommodates all available biochemical data and appears competent for catalysis. The position of this metal is consistent with a role of a magnesium-bound hydroxide as a general base as dictated by biochemical data. PMID:19178151

  1. Engineering D-Amino Acid Containing Collagen Like Peptide at the Cleavage Site of Clostridium histolyticum Collagenase for Its Inhibition.

    Directory of Open Access Journals (Sweden)

    Punitha Velmurugan

    Full Text Available Collagenase is an important enzyme which plays an important role in degradation of collagen in wound healing, cancer metastasis and even in embryonic development. However, the mechanism of this degradation has not yet been completely understood. In the field of biomedical and protein engineering, the design and development of new peptide based materials is of main concern. In the present work an attempt has been made to study the effect of DAla in collagen like peptide (imino-poor region of type I collagen on the structure and stability of peptide against enzyme hydrolysis. Effect of replacement of DAla in the collagen like peptide has been studied using circular dichroic spectroscopy (CD. Our findings suggest that, DAla substitution leads to conformational changes in the secondary structure and favours the formation of polyproline II conformation than its L-counterpart in the imino-poor region of collagen like peptides. Change in the chirality of alanine at the cleavage site of collagenase in the imino-poor region inhibits collagenolytic activity. This may find application in design of peptides and peptidomimics for enzyme-substrate interaction, specifically with reference to collagen and other extra cellular matrix proteins.

  2. Mutations near the cleavage site of enterocin NKR-5-3B prepeptide reveal new insights into its biosynthesis.

    Science.gov (United States)

    Perez, Rodney H; Sugino, Haruki; Ishibashi, Naoki; Zendo, Takeshi; Wilaipun, Pongtep; Leelawatcharamas, Vichien; Nakayama, Jiro; Sonomoto, Kenji

    2017-04-01

    Enterocin NKR-5-3B (Ent53B) is a 64-residue novel circular bacteriocin synthesized from an 87-residue prepeptide. Albeit through a still unknown mechanism, the EnkB1234 biosynthetic enzyme complex processes the prepeptide to yield its mature active, circular form. To gain insights into the key region/residue that plays a role in Ent53 maturation, several mutations near the cleavage site on the precursor peptide were generated. The interaction of the precursor peptide and EnkB1234 appeared to be hydrophobic in nature. At the Leu1 position, only mutations with helix structure-promoting hydrophobic residues (Ala, Ile, Val or Phe) were able to yield the mature Ent53B derivative. In this study, we also highlight the possible conformation-stabilizing role of the Ent53B leader peptide on the precursor peptide for its interaction with its biosynthetic enzyme complex. Any truncations of the leader peptide moiety interfered in the processing of the prepeptide. However, when propeptides of other circular bacteriocins (circularin A, leucocyclicin Q or lactocyclicin Q) were cloned at the C-terminus of the leader peptide, EnkB1234 could not process them to yield a mature bacteriocin. Taken together, these findings offer new perspectives in our understanding of the possible molecular mechanism of the biosynthesis of this circular bacteriocin. These new perspectives will help advance our current understanding to eventually elucidate circular bacteriocin biosynthesis. Understanding the biosynthetic mechanism of circular bacteriocins will materialize their application potential.

  3. Crystal structure of Bombyx mori arylphorins reveals a 3:3 heterohexamer with multiple papain cleavage sites

    Science.gov (United States)

    Hou, Yong; Li, Jianwei; Li, Yi; Dong, Zhaoming; Xia, Qingyou; Yuan, Y Adam

    2014-01-01

    In holometabolous insects, the accumulation and utilization of storage proteins (SPs), including arylphorins and methionine-rich proteins, are critical for the insect metamorphosis. SPs function as amino acids reserves, which are synthesized in fat body, secreted into the larval hemolymph and taken up by fat body shortly before pupation. However, the detailed molecular mechanisms of digestion and utilization of SPs during development are largely unknown. Here, we report the crystal structure of Bombyx mori arylphorins at 2.8 Å, which displays a heterohexameric structural arrangement formed by trimerization of dimers comprising two structural similar arylphorins. Our limited proteolysis assay and microarray data strongly suggest that papain-like proteases are the major players for B. mori arylphorins digestion in vitro and in vivo. Consistent with the biochemical data, dozens of papain cleavage sites are mapped on the surface of the heterohexameric structure of B. mori arylphorins. Hence, our results provide the insightful information to understand the metamorphosis of holometabolous insects at molecular level. PMID:24639361

  4. Inhibition of Lassa virus glycoprotein cleavage and multicycle replication by site 1 protease-adapted alpha(1-antitrypsin variants.

    Directory of Open Access Journals (Sweden)

    Anna Maisa

    2009-06-01

    Full Text Available Proteolytic processing of the Lassa virus envelope glycoprotein precursor GP-C by the host proprotein convertase site 1 protease (S1P is a prerequisite for the incorporation of the subunits GP-1 and GP-2 into viral particles and, hence, essential for infectivity and virus spread. Therefore, we tested in this study the concept of using S1P as a target to block efficient virus replication.We demonstrate that stable cell lines inducibly expressing S1P-adapted alpha(1-antitrypsin variants inhibit the proteolytic maturation of GP-C. Introduction of the S1P recognition motifs RRIL and RRLL into the reactive center loop of alpha(1-antitrypsin resulted in abrogation of GP-C processing by endogenous S1P to a similar level observed in S1P-deficient cells. Moreover, S1P-specific alpha(1-antitrypsins significantly inhibited replication and spread of a replication-competent recombinant vesicular stomatitis virus expressing the Lassa virus glycoprotein GP as well as authentic Lassa virus. Inhibition of viral replication correlated with the ability of the different alpha(1-antitrypsin variants to inhibit the processing of the Lassa virus glycoprotein precursor.Our data suggest that glycoprotein cleavage by S1P is a promising target for the development of novel anti-arenaviral strategies.

  5. Disclosure of key stereoelectronic factors for efficient H2 binding and cleavage in the active site of [NiFe]-hydrogenases.

    Science.gov (United States)

    Bruschi, Maurizio; Tiberti, Matteo; Guerra, Alessandro; De Gioia, Luca

    2014-02-05

    A comparative analysis of a series of DFT models of [NiFe]-hydrogenases, ranging from minimal NiFe clusters to very large systems including both the first and second coordination sphere of the bimetallic cofactor, was carried out with the aim of unraveling which stereoelectronic properties of the active site of [NiFe]-hydrogenases are crucial for efficient H2 binding and cleavage. H2 binding to the Ni-SIa redox state is energetically favored (by 4.0 kcal mol(-1)) only when H2 binds to Ni, the NiFe metal cluster is in a low spin state, and the Ni cysteine ligands have a peculiar seesaw coordination geometry, which in the enzyme is stabilized by the protein environment. The influence of the Ni coordination geometry on the H2 binding affinity was then quantitatively evaluated and rationalized analyzing frontier molecular orbitals and populations. Several plausible reaction pathways leading to H2 cleavage were also studied. It turned out that a two-step pathway, where H2 cleavage takes place on the Ni-SIa redox state of the enzyme, is characterized by very low reaction barriers and favorable reaction energies. More importantly, the seesaw coordination geometry of Ni was found to be a key feature for facile H2 cleavage. The discovery of the crucial influence of the Ni coordination geometry on H2 binding and activation in the active site of [NiFe]-hydrogenases could be exploited in the design of novel biomimetic synthetic catalysts.

  6. Novel factor VIII variants with a modified furin cleavage site improve the efficacy of gene therapy for hemophilia A.

    Science.gov (United States)

    Nguyen, G N; George, L A; Siner, J I; Davidson, R J; Zander, C B; Zheng, X L; Arruda, V R; Camire, R M; Sabatino, D E

    2017-01-01

    Essentials Factor (F) VIII is an inefficiently expressed protein. Furin deletion FVIII variants were purified and characterized using in vitro and in vivo assays. These minimally modified novel FVIII variants have enhanced function. These variants provide a strategy for increasing FVIII expression in hemophilia A gene therapy. Background The major challenge for developing gene-based therapies for hemophilia A is that human factor VIII (hFVIII) has intrinsic properties that result in inefficient biosynthesis. During intracellular processing, hFVIII is predominantly cleaved at a paired basic amino acid cleaving enzyme (PACE) or furin cleavage site to yield a heterodimer that is the major form of secreted protein. Previous studies with B-domain-deleted (BDD) canine FVIII and hFVIII-R1645H, both differing from hFVIII by a single amino acid at this site, suggested that these proteins are secreted mainly in a single polypeptide chain (SC) form and exhibit enhanced function. Objective We hypothesized that deletion(s) of the furin site modulates FVIII biology and may enhance its function. Methods A series of recombinant hFVIII-furin deletion variants were introduced into hFVIII-BDD [Δ1645, 1645-46(Δ2), 1645-47(Δ3), 1645-48(Δ4), or Δ1648] and characterized. Results In vitro, recombinant purified Δ3 and Δ4 were primarily SC and, interestingly, had 2-fold higher procoagulant activity compared with FVIII-BDD. In vivo, the variants also have improved hemostatic function. After adeno-associated viral (AAV) vector delivery, the expression of these variants is 2-4-fold higher than hFVIII-BDD. Protein challenges of each variant in mice tolerant to hFVIII-BDD showed no anti-FVIII immune response. Conclusions These data suggest that the furin deletion hFVIII variants are superior to hFVIII-BDD without increased immunogenicity. In the setting of gene-based therapeutics, these novel variants provide a unique strategy to increase FVIII expression, thus lowering the vector dose, a

  7. A comparative study of matrix metalloproteinase and aggrecanase mediated release of latent cytokines at arthritic joints.

    Science.gov (United States)

    Mullen, Lisa; Adams, Gill; Foster, Julie; Vessillier, Sandrine; Köster, Mario; Hauser, Hansjörg; Layward, Lorna; Gould, David; Chernajovsky, Yuti

    2014-09-01

    Latent cytokines are engineered by fusing the latency associated peptide (LAP) derived from transforming growth factor-β (TGF-β) with the therapeutic cytokine, in this case interferon-β (IFN-β), via an inflammation-specific matrix metalloproteinase (MMP) cleavage site. To demonstrate latency and specific delivery in vivo and to compare therapeutic efficacy of aggrecanase-mediated release of latent IFN-β in arthritic joints to the original MMP-specific release. Recombinant fusion proteins with MMP, aggrecanase or devoid of cleavage site were expressed in CHO cells, purified and characterised in vitro by Western blotting and anti-viral protection assays. Therapeutic efficacy and half-life were assessed in vivo using the mouse collagen-induced arthritis model (CIA) of rheumatoid arthritis and a model of acute paw inflammation, respectively. Transgenic mice with an IFN-regulated luciferase gene were used to assess latency in vivo and targeted delivery to sites of disease. Efficient localised delivery of IFN-β to inflamed paws, with low levels of systemic delivery, was demonstrated in transgenic mice using latent IFN-β. Engineering of latent IFN-β with an aggrecanase-sensitive cleavage site resulted in efficient cleavage by ADAMTS-4, ADAMTS-5 and synovial fluid from arthritic patients, with an extended half-life similar to the MMP-specific molecule and greater therapeutic efficacy in the CIA model. Latent cytokines require cleavage in vivo for therapeutic efficacy, and they are delivered in a dose dependent fashion only to arthritic joints. The aggrecanase-specific cleavage site is a viable alternative to the MMP cleavage site for the targeting of latent cytokines to arthritic joints. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  8. Possible cleavage sites of glutelin partial degradation confirmed by immunological analysis in globulin-less mutants of rice (Oryza sativa L.).

    Science.gov (United States)

    Khan, Nadar; Yamaguchi, Satoru; Katsube-Tanaka, Tomoyuki

    2017-10-01

    Proteolytic cleavage or partial degradation of proteins is one of the important post-translational modifications for various biological processes, but it is difficult to analyze. Previously, we demonstrated that some subunits of the major rice (Oryza sativa L.) seed storage protein glutelin are partially degraded to produce newly identified polypeptides X1-X5 in mutants in which another major seed storage protein globulin is absent. In this study, the new polypeptides X3 and X4/X5 were immunologically confirmed to be derived from GluA3 and GluA1/GluA2 subunits, respectively. Additionally, the new polypeptides X1 and X2 were at least in part the α polypeptides of the GluB4 subunit partially degraded at the C-terminus. Simulated 2D-PAGE migration patterns of intact and partially degraded α polypeptides based on the calculation of their MWs and pIs enabled us to narrow or predict the possible locations of cleavage sites. The predicted cleavage sites were also verified by the comparison of 2D-PAGE patterns between seed-extracted and E. coli-expressed proteins of the intact and truncated α polypeptides. The results and methodologies demonstrated here would be useful for analyses of partial degradation of proteins and the structure-function relationships of rice seed protein bodies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Mapping DNA cleavage by the Type ISP restriction-modification enzymes following long-range communication between DNA sites in different orientations

    Science.gov (United States)

    van Aelst, Kara; Saikrishnan, Kayarat; Szczelkun, Mark D.

    2015-01-01

    The prokaryotic Type ISP restriction-modification enzymes are single-chain proteins comprising an Mrr-family nuclease, a superfamily 2 helicase-like ATPase, a coupler domain, a methyltransferase, and a DNA-recognition domain. Upon recognising an unmodified DNA target site, the helicase-like domain hydrolyzes ATP to cause site release (remodeling activity) and to then drive downstream translocation consuming 1–2 ATP per base pair (motor activity). On an invading foreign DNA, double-strand breaks are introduced at random wherever two translocating enzymes form a so-called collision complex following long-range communication between a pair of target sites in inverted (head-to-head) repeat. Paradoxically, structural models for collision suggest that the nuclease domains are too far apart (>30 bp) to dimerise and produce a double-strand DNA break using just two strand-cleavage events. Here, we examined the organisation of different collision complexes and how these lead to nuclease activation. We mapped DNA cleavage when a translocating enzyme collides with a static enzyme bound to its site. By following communication between sites in both head-to-head and head-to-tail orientations, we could show that motor activity leads to activation of the nuclease domains via distant interactions of the helicase or MTase-TRD. Direct nuclease dimerization is not required. To help explain the observed cleavage patterns, we also used exonuclease footprinting to demonstrate that individual Type ISP domains can swing off the DNA. This study lends further support to a model where DNA breaks are generated by multiple random nicks due to mobility of a collision complex with an overall DNA-binding footprint of ∼30 bp. PMID:26507855

  10. CleavPredict: A Platform for Reasoning about Matrix Metalloproteinases Proteolytic Events.

    Directory of Open Access Journals (Sweden)

    Sonu Kumar

    Full Text Available CleavPredict (http://cleavpredict.sanfordburnham.org is a Web server for substrate cleavage prediction for matrix metalloproteinases (MMPs. It is intended as a computational platform aiding the scientific community in reasoning about proteolytic events. CleavPredict offers in silico prediction of cleavage sites specific for 11 human MMPs. The prediction method employs the MMP specific position weight matrices (PWMs derived from statistical analysis of high-throughput phage display experimental results. To augment the substrate cleavage prediction process, CleavPredict provides information about the structural features of potential cleavage sites that influence proteolysis. These include: secondary structure, disordered regions, transmembrane domains, and solvent accessibility. The server also provides information about subcellular location, co-localization, and co-expression of proteinase and potential substrates, along with experimentally determined positions of single nucleotide polymorphism (SNP, and posttranslational modification (PTM sites in substrates. All this information will provide the user with perspectives in reasoning about proteolytic events. CleavPredict is freely accessible, and there is no login required.

  11. Fluorescence quenching of graphene oxide combined with the site-specific cleavage of restriction endonuclease for deoxyribonucleic acid demethylase activity assay

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Lijuan; Qian, Yingdan; Wu, Ping; Zhang, Hui; Cai, Chenxin, E-mail: cxcai@njnu.edu.cn

    2015-04-15

    Highlights: • An approach for sensitive and selective DNA demethylase activity assay is reported. • This assay is based on the fluorescence quenching of GO and site-specific cleavage of endonuclease. • It can determine as low as 0.05 ng mL{sup −1} of MBD2 with a linear range of 0.2–300 ng mL{sup −1}. • It has an ability to recognize MBD2 from other possibly coexisting proteins and cancer cell extracts. • It can avoid false signals, requiring no bisulfite conversion, PCR amplification, radioisotope-labeling. - Abstract: We report on the development of a sensitive and selective deoxyribonucleic acid (DNA) demethylase (using MBD2 as an example) activity assay by coupling the fluorescence quenching of graphene oxide (GO) with the site-specific cleavage of HpaII endonuclease to improve the selectivity. This approach was developed by designing a single-stranded probe (P1) that carries a binding region to facilitate the interaction with GO, which induces fluorescence quenching of the labeled fluorophore (FAM, 6-carboxyfluorescein), and a sensing region, which contains a hemi-methylated site of 5′-CmCGG-3′, to specifically recognize the target (T1, a 32-mer DNA from the promoter region of p53 gene) and hybridize with it to form a P1/T1 duplex. After demethylation with MBD2, the duplex can be specifically cleaved using HpaII, which releases the labeled FAM from the GO surface and results in the recovery of fluorescence. However, this cleavage is blocked by the hemi-methylation of this site. Thus, the magnitude of the recovered fluorescence signal is related to the MBD2 activity, which establishes the basis of the DNA demethylase activity assay. This assay can determine as low as ∼(0.05 ± 0.01) ng mL{sup −1} (at a signal/noise of 3) of MBD2 with a linear range of 0.2–300 ng mL{sup −1} and recognize MBD2 from other possibly coexisting proteins and cancer cell extracts. The advantage of this assay is its ability to avoid false signals and no

  12. Analysis of apolipoprotein A-I as a substrate for matrix metalloproteinase-14

    International Nuclear Information System (INIS)

    Park, Jun Hyoung; Park, Sung-Min; Park, Ki-Hoon; Cho, Kyung-Hyun; Lee, Seung-Taek

    2011-01-01

    Highlights: → MMP-14 degrades apoA-I more efficiently than other tested MMPs. → Lipid-free apoA-I is more susceptible to MMPs than lipid-bound apoA-I. → MMP-14 cleavage sites on apoA-I have been determined. → Cleavage of apoA-I by MMP-14 impairs its ability to form HDL. -- Abstract: Substrates for matrix metalloproteinase (MMP)-14 were previously identified in human plasma using proteomic techniques. One putative MMP-14 substrate was apolipoprotein A-I (apoA-I), a major component of high-density lipoprotein (HDL). In vitro cleavage assays showed that lipid-free apoA-I is a more accessible substrate for MMP-14 compared to lipid-bound apoA-I, and that MMP-14 is more prone to digest apoA-I than MMP-3. The 28-kDa apoA-I was cleaved into smaller fragments of 27, 26, 25, 22, and 14-kDa by MMP-14. ApoA-I sites cleaved by MMP-14 were determined by isotope labeling of C-termini derived from the cleavage and analysis of the labeled peptides by mass spectrometry, along with N-terminal sequencing of the fragments. Cleavage of apoA-I by MMP-14 resulted in a loss of ability to form HDL. Our results suggest that cleavage of lipid-free apoA-I by MMP-14 may contribute to reduced HDL formation, and this may be occurring during the development of various vascular diseases as lipid metabolism is disrupted.

  13. Beneficial effect of antibodies against β- secretase cleavage site of APP on Alzheimer's-like pathology in triple-transgenic mice.

    Directory of Open Access Journals (Sweden)

    Inna Rabinovich-Nikitin

    Full Text Available The toxicity of amyloid β and tau, the two hallmark proteins in Alzheimer's disease (AD, has been extensively studied individually. Recently new data suggest their possible interactions and synergistic effects in the disease. In this study, we investigate the ability of antibodies against the β secretase cleavage site on APP, named BBS1, to affect tau pathology, besides their well established effect on intracellular Aβ and amyloid load. For this purpose we treated the triple transgenic mice model of AD (3x Tg-AD with mAb BBS1 intracerebroventricularly, using mini osmotic pumps for one month. The experimental data demonstrated reduction in total and phosphorylated tau levels, explained by significant reduction in GSK3β which phosphorylates tau on sites recognized by antibodies against PHF1 and AT-8. The treatment increased the cognitive capabilities and reduced the brain inflammation levels which accompany AD pathology. The data showing that tau pathology was significantly reduced by BBS1 antibodies suggest a close interaction between tau and Aβ in the development of AD, and may serve as an efficient novel immunotherapy against both hallmarks of this disease.

  14. Albumin Redhill (-1 Arg, 320 Ala → Thr): A glycoprotein variant of human serum albumin whose precursor has an aberrant signal peptidase cleavage site

    International Nuclear Information System (INIS)

    Brennan, S.O.; Myles, T.; Peach, R.J.; George, P.M.; Donaldson, D.

    1990-01-01

    Albumin Redhill is an electrophoretically slow genetic variant of human serum albumin that does not bind 63 Ni 2+ and has a molecular mass 2.5 kDa higher than normal albumin. Its inability to bind Ni 2+ was explained by the finding of an additional residue of Arg at position -1. This did not explain the molecular basis of the genetic variation or the increase in apparent molecular mass. Fractionation of tryptic digests on concanavalin A-Sepharose followed by peptide mapping of the bound and unbound fractions and sequence analysis of the glycopeptides identified a mutation of 320 Ala → Thr. This introduces as Asn-Tyr-Thr oligosaccharide attachment sequence centered on Asn-318 and explains the increase in molecular mass. This, however, did not satisfactorily explain the presence of the additional Arg residue at position -1. DNA sequencing of polymerase chain reaction-amplified genomic DNA encoding the prepro sequence of albumin indicated an additional mutation of -2 Arg → Cys. The authors propose that the new Phe-Cys-Arg sequence in the propeptide is an aberrant signal peptidase cleavage site and that the signal peptidase cleaves the propeptide of albumin Redhill in the lumen of the endoplasmic reticulum before it reaches the Golgi vesicles, the site of the diarginyl-specific proalbumin convertase

  15. Group I-like ribozymes with a novel core organization perform obligate sequential hydrolytic cleavages at two processing sites

    DEFF Research Database (Denmark)

    Einvik, C; Nielsen, Henrik; Westhof, E

    1998-01-01

    A new category of self-splicing group I introns with conserved structural organization and function is found among the eukaryotic microorganisms Didymium and Naegleria. These complex rDNA introns contain two distinct ribozymes with different functions: a regular group I splicing...... available GIR1 sequences and propose a common RNA secondary structure resembling that of group I splicing-ribozymes, but with some important differences. The GIR1s lack most peripheral sequence components, as well as a P1 segment, and, at approximately 160-190 nt, they are the smallest functional group I...... ribozymes known from nature. All GIR1s were found to contain a novel 6-bp pseudoknot (P15) within their catalytic core region. Experimental support of the proposed structure was obtained from the Didymium GIR1 by RNA structure probing and site-directed mutagenesis. Three-dimensional modeling indicates...

  16. Systematic Design of Trypsin Cleavage Site Mutated Exendin4-Cysteine 1, an Orally Bioavailable Glucagon-Like Peptide-1 Receptor Agonist

    Directory of Open Access Journals (Sweden)

    Wenbo Sai

    2017-03-01

    Full Text Available Exendin-4 is a strong therapeutic candidate for the treatment of metabolic syndrome. Related receptor agonist drugs have been on the market since 2005. However, technical limitations and the pain caused by subcutaneous injection have severely limited patient compliance. The goal of the study is to investigate a biologically active exendin-4 analog could be administered orally. Using intraperitoneal glucose tolerance tests, we discovered that exendin4-cysteine administered by oral gavage had a distinct hypoglycemic effect in C57BL/6J mice. Using Rosetta Design and Amber, we designed and screened a series of exendin4-cysteine analogs to identify those that retained biological activity while resisting trypsin digestion. Trypsin Cleavage Site Mutated Exendin4-cysteine 1 (TSME-1, an analog whose bioactivity was similar to exendin-4 and was almost completely resistant to trypsin, was screened out. In addition, TSME-1 significantly normalized the blood glucose levels and the availability of TSME-1 was significantly higher than that of exendin-4 and exendin4-cysteine. Collectively orally administered TSME-1, a trypsin-resistant exendin-4 analog obtained by the system, is a strong candidate for future treatments of type 2 diabetes.

  17. Mutation in the protease cleavage site of GDF9 increases ovulation rate and litter size in heterozygous ewes and causes infertility in homozygous ewes.

    Science.gov (United States)

    Souza, C J H; McNeilly, A S; Benavides, M V; Melo, E O; Moraes, J C F

    2014-10-01

    Litter size (LS) in sheep is determined mainly by ovulation rate (OR). Several polymorphisms have been identified in the growth differentiation factor 9 (GDF9) gene that result in an increase in OR and prolificacy of sheep. Screening the databank of the Brazilian Sheep Breeders Association for triplet delivery, we identified flocks of prolific Ile de France ewes. After resequencing of GDF9, a point mutation (c.943C>T) was identified, resulting in a non-conservative amino acid change (p.Arg315Cys) in the cleavage site of the propeptide. This new allele was called Vacaria (FecG(v) ). A flock of half-sib ewes was evaluated for OR in the first three breeding seasons, and Vacaria heterozygotes had higher OR (P develop up to small antral stages, although with abnormal oocyte morphology and altered arrangement of granulosa cells. After the collapse of the oocyte in most follicles, the remaining cells formed clusters that persisted in the ovary. This SNP is useful to improve selection for dam prolificacy and also as a model to investigate GDF9 post-translation processing and the fate of the follicular cells that remain after the oocyte demise. © 2014 Stichting International Foundation for Animal Genetics.

  18. [Prokaryotic expression and immunogenicity analysis of the chimeric HBcAg containing APP beta cleavage site peptide and Aβ(1-15);].

    Science.gov (United States)

    Feng, Gai-feng; Wang, Jun-yang; Jin, Hui; Wang, Wei-xi; Qian, Yi-hua; Yang, Wei-na; Wang, Quan-ying; Yang, Guang-xiao

    2011-11-01

    To construct the recombinant prokaryotic expression plasmid pET/c-ABCSP-Aβ(15-c);, and evaluate the immunogenicity of the fusion protein expressed in E.coli. The gene fragment HBc88-144 was amplified by PCR and subcloned to pUC19. The APP beta cleavage site peptide(ABCSP) and Aβ(1-15); gene(ABCSP-Aβ(15);) was amplified by PCR and inserted downstream of HBc1-71 in pGEMEX/c1-71. After restriction enzyme digestion, c1-17-ABCSP-Aβ(15); were connected with HBc88-144, yielding the recombinant gene c-ABCSP-Aβ(15-c);. c-ABCSP-Aβ(15-c); gene was subcloned into pET-28a(+).The fusion protein expressed in transformed E.coli BL21 was induced with IPTG and analyzed by SDS-PAGE. The virus-like particles (VLP) formed by fusion protein was observed with Transmission Electron Microscope (TEM). 4 Kunming (KM) mice received intraperitoneal injection (i.p) of fusion protein VLP. The antibody was detected by indirect ELISA. The recombinant gene was confirmed by restriction enzyme digestion and DNA sequencing. After IPTG induction, fusion protein was expressed and mainly existed in the sediment of the bacterial lysate. The expression level was 40% of all the proteins in the sediment. The fusion protein could form VLP. After 5 times of immunization, the titer of anti-ABCSP and anti-Aβantibody in sera of KM mice reached up to 1:5 000 and 1:10 000 respectively, while the anti-HBc antibody was undetectable. Recombinant c-ABCSP-Aβ(15-c); gene can be expressed in E.coli. The expressed protein could form VLP and has a strong immunogenicity. This study lays the foundation for the study of AD genetic engineering vaccine.

  19. Matrix Metalloproteinase Enzyme Family

    Directory of Open Access Journals (Sweden)

    Ozlem Goruroglu Ozturk

    2013-04-01

    Full Text Available Matrix metalloproteinases play an important role in many biological processes such as embriogenesis, tissue remodeling, wound healing, and angiogenesis, and in some pathological conditions such as atherosclerosis, arthritis and cancer. Currently, 24 genes have been identified in humans that encode different groups of matrix metalloproteinase enzymes. This review discuss the members of the matrix metalloproteinase family and their substrate specificity, structure, function and the regulation of their enzyme activity by tissue inhibitors. [Archives Medical Review Journal 2013; 22(2.000: 209-220

  20. In vitro maturation of Drosophila melanogaster Spätzle protein with refolded Easter reveals a novel cleavage site within the prodomain.

    Science.gov (United States)

    Ursel, Christian; Fandrich, Uwe; Hoffmann, Anita; Sieg, Torsten; Ihling, Christian; Stubbs, Milton T

    2013-08-01

    Dorsoventral patterning during Drosophila melanogaster embryogenesis is mediated by a well-defined gradient of the mature NGF-like ligand Spätzle. Easter, the ultimate protease of a ventrally-restricted serine protease cascade, plays a key role in the regulation of the morphogenic gradient, catalyzing the activation cleavage of proSpätzle. As a result of alternative splicing, proSpätzle exists in multiple isoforms, almost all of which differ only in their prodomain. Although this domain is unstructured in isolation, it has a stabilizing influence on the mature cystine knot domain and is involved in the binding to the Toll receptor. Here, we report the expression and refolding of Easter, and show that the renatured enzyme performs the activation cleavage of two Spätzle isoforms. We determine the affinity of the prodomain for the cystine knot domain, and show that Easter performs a previously unknown secondary cleavage in each prodomain.

  1. Snake Venom Metalloproteinases

    Directory of Open Access Journals (Sweden)

    Gâz Florea Şerban Andrei

    2016-03-01

    Full Text Available As more data are generated from proteome and transcriptome analysis revealing that metalloproteinases represent most of the Viperid and Colubrid venom components authors decided to describe in a short review a classification and some of the multiple activities of snake venom metalloproteinases. SVMPs are classified in three major classes (P-I, P-II and P-III classes based on the presence of various domain structures and according to their domain organization. Furthermore, P-II and P-III classes were separated in subclasses based on distinctive post-translational modifications. SVMPs are synthesized in a latent form, being activated through a Cys-switch mechanism similar to matrix metalloproteinases. Most of the metalloproteinases of the snake venom are responsible for the hemorrhagic events but also have fibrinogenolytic activity, poses apoptotic activity, activate blood coagulation factor II and X, inhibit platelet aggregation, demonstrating that SVMPs have multiple functions in addition to well-known hemorrhagic function.

  2. Snake Venom Metalloproteinases

    OpenAIRE

    Gâz Florea Şerban Andrei; Gâz Florea Adriana; Kelemen Hajnal; Muntean Daniela-Lucia

    2016-01-01

    As more data are generated from proteome and transcriptome analysis revealing that metalloproteinases represent most of the Viperid and Colubrid venom components authors decided to describe in a short review a classification and some of the multiple activities of snake venom metalloproteinases. SVMPs are classified in three major classes (P-I, P-II and P-III classes) based on the presence of various domain structures and according to their domain organization. Furthermore, P-II and P-III clas...

  3. Human adenovirus serotype 12 virion precursors pMu and pVI are cleaved at amino-terminal and carboxy-terminal sites that conform to the adenovirus 2 endoproteinase cleavage consensus sequence.

    Science.gov (United States)

    Freimuth, P; Anderson, C W

    1993-03-01

    The sequence of a 1158-base pair fragment of the human adenovirus serotype 12 (Ad12) genome was determined. This segment encodes the precursors for virion components Mu and VI. Both Ad12 precursors contain two sequences that conform to a consensus sequence motif for cleavage by the endoproteinase of adenovirus 2 (Ad2). Analysis of the amino terminus of VI and of the peptide fragments found in Ad12 virions demonstrated that these sites are cleaved during Ad12 maturation. This observation suggests that the recognition motif for adenovirus endoproteinases is highly conserved among human serotypes. The adenovirus 2 endoproteinase polypeptide requires additional co-factors for activity (C. W. Anderson, Protein Expression Purif., 1993, 4, 8-15). Synthetic Ad12 or Ad2 pVI carboxy-terminal peptides each permitted efficient cleavage of an artificial endoproteinase substrate by recombinant Ad2 endoproteinase polypeptide.

  4. In vivo analysis of the Notch receptor S1 cleavage.

    Directory of Open Access Journals (Sweden)

    Robert J Lake

    2009-08-01

    Full Text Available A ligand-independent cleavage (S1 in the extracellular domain of the mammalian Notch receptor results in what is considered to be the canonical heterodimeric form of Notch on the cell surface. The in vivo consequences and significance of this cleavage on Drosophila Notch signaling remain unclear and contradictory. We determined the cleavage site in Drosophila and examined its in vivo function by a transgenic analysis of receptors that cannot be cleaved. Our results demonstrate a correlation between loss of cleavage and loss of in vivo function of the Notch receptor, supporting the notion that S1 cleavage is an in vivo mechanism of Notch signal control.

  5. Functional study of elafin cleaved by Pseudomonas aeruginosa metalloproteinases.

    LENUS (Irish Health Repository)

    Guyot, Nicolas

    2010-06-01

    Elafin is a 6-kDa innate immune protein present at several epithelial surfaces including the pulmonary epithelium. It is a canonical protease inhibitor of two neutrophil serine proteases [neutrophil elastase (NE) and proteinase 3] with the capacity to covalently bind extracellular matrix proteins by transglutamination. In addition to these properties, elafin also possesses antimicrobial and immunomodulatory activities. The aim of the present study was to investigate the effect of Pseudomonas aeruginosa proteases on elafin function. We found that P. aeruginosa PAO1-conditioned medium and two purified Pseudomonas metalloproteases, pseudolysin (elastase) and aeruginolysin (alkaline protease), are able to cleave recombinant elafin. Pseudolysin was shown to inactivate the anti-NE activity of elafin by cleaving its protease-binding loop. Interestingly, antibacterial properties of elafin against PAO1 were found to be unaffected after pseudolysin treatment. In contrast to pseudolysin, aeruginolysin failed to inactivate the inhibitory properties of elafin against NE. Aeruginolysin cleaves elafin at the amino-terminal Lys6-Gly7 peptide bond, resulting in a decreased ability to covalently bind purified fibronectin following transglutaminase activity. In conclusion, this study provides evidence that elafin is susceptible to proteolytic cleavage at alternative sites by P. aeruginosa metalloproteinases, which can affect different biological functions of elafin.

  6. N-Glycosylation Improves the Pepsin Resistance of Histidine Acid Phosphatase Phytases by Enhancing Their Stability at Acidic pHs and Reducing Pepsin's Accessibility to Its Cleavage Sites

    Science.gov (United States)

    Niu, Canfang; Luo, Huiying; Shi, Pengjun; Huang, Huoqing; Wang, Yaru; Yang, Peilong

    2015-01-01

    N-Glycosylation can modulate enzyme structure and function. In this study, we identified two pepsin-resistant histidine acid phosphatase (HAP) phytases from Yersinia kristensenii (YkAPPA) and Yersinia rohdei (YrAPPA), each having an N-glycosylation motif, and one pepsin-sensitive HAP phytase from Yersinia enterocolitica (YeAPPA) that lacked an N-glycosylation site. Site-directed mutagenesis was employed to construct mutants by altering the N-glycosylation status of each enzyme, and the mutant and wild-type enzymes were expressed in Pichia pastoris for biochemical characterization. Compared with those of the N-glycosylation site deletion mutants and N-deglycosylated enzymes, all N-glycosylated counterparts exhibited enhanced pepsin resistance. Introduction of the N-glycosylation site into YeAPPA as YkAPPA and YrAPPA conferred pepsin resistance, shifted the pH optimum (0.5 and 1.5 pH units downward, respectively) and improved stability at acidic pH (83.2 and 98.8% residual activities at pH 2.0 for 1 h). Replacing the pepsin cleavage sites L197 and L396 in the immediate vicinity of the N-glycosylation motifs of YkAPPA and YrAPPA with V promoted their resistance to pepsin digestion when produced in Escherichia coli but had no effect on the pepsin resistance of N-glycosylated enzymes produced in P. pastoris. Thus, N-glycosylation may improve pepsin resistance by enhancing the stability at acidic pH and reducing pepsin's accessibility to peptic cleavage sites. This study provides a strategy, namely, the manipulation of N-glycosylation, for improvement of phytase properties for use in animal feed. PMID:26637601

  7. Purification and characterization of a novel milk-clotting metalloproteinase from Paenibacillus spp. BD3526.

    Science.gov (United States)

    Hang, Feng; Wang, Qinbo; Hong, Qing; Liu, Peiyi; Wu, Zhengjun; Liu, Zhenmin; Zhang, Hao; Chen, Wei

    2016-04-01

    In this study, a milk-clotting enzyme (MCE) isolated from Paenibacillus spp. BD3526 was purified and characterized. The MCE was purified 8.9-fold with a 10.11% recovery using ammonium sulfate precipitation and anion-exchange chromatography and the specific milk-clotting activity (MCA) reached 6791.73 SU/mg. The enzyme was characterized as a 35kDa metalloproteinase, and the zymogen of which was encoded by a 1671 bp gene named zinc metalloproteinase precursor (zmp) with a predicted molecular weight of 59.6 kDa. The optimal temperature for MCA and proteolytic activity (PA) was 65°C and 60°C, respectively. The enzyme was stable over a pH range of 5.0-9.0 and at temperatures below 50°C. The MCA was completely inactivated when the enzyme was heated at 60°C for 30 min, and the PA was totally inactivated for 20 and 10 min when the enzyme was heated at 55°C and 60°C, respectively. The BD3526 enzyme was preferentially active towards κ-casein (κ-CN) and β-casein (β-CN), as determined by sodium dodecyl sulfate-polyacrylamide gels (SDS-PAGE), whereas the hydrolysis of αs-casein (αs-CN) was slow and comparable to that caused by chymosin and asparatic acid proteinase from Rhizomucor miehei. The cleavage site of the metalloproteinase in κ-CN was located at the Met106-Ala107 bond, as determined by mass spectrometry analysis. Copyright © 2016. Published by Elsevier B.V.

  8. Mechanistic Studies on the Triggered Release of Liposomal Contents by Matrix Metalloproteinase-9

    Science.gov (United States)

    Elegbede, Adekunle I.; Banerjee, Jayati; Hanson, Andrea J.; Tobwala, Shakila; Ganguli, Bratati; Wang, Rongying; Lu, Xiaoning; Srivastava, D. K.; Mallik, Sanku

    2009-01-01

    Matrix metalloproteinases (MMPs) are a class of extracellular matrix degrading enzymes over-expressed in many cancers and contribute to the metastatic ability of the cancer cells. We have recently demonstrated that liposomal contents can be released when triggered by the enzyme MMP-9. Herein, we report our results on the mechanistic studies of the MMP-9 triggered release of the liposomal contents. We synthesized peptides containing the cleavage site for MMP-9 and conjugated them with fatty acids to prepare the corresponding lipopeptides. By employing Circular Dichroism spectroscopy, we demonstrate that the lipopeptides, when incorporated in liposomes, are de-mixed in the lipid bilayers and generate triple helical structures. MMP-9 cleaves the triple helical peptides, leading to the release of the liposomal contents. Other MMPs, which cannot hydrolyze triple helical peptides, failed to release the contents from the liposomes. We also observed that the rate and the extent of release of the liposomal contents depend on the mismatch between acyl chains of the synthesized lipopeptide and phospholipid components of the liposomes. Circular Dichroism spectroscopic studies imply that the observed differences in the release reflect the ability of the liposomal membrane to anneal the defects following the enzymatic cleavage of the liposome-incorporated lipopeptides. PMID:18642903

  9. H9N2 influenza virus acquires intravenous pathogenicity on the introduction of a pair of di-basic amino acid residues at the cleavage site of the hemagglutinin and consecutive passages in chickens

    Directory of Open Access Journals (Sweden)

    Sakoda Yoshihiro

    2011-02-01

    Full Text Available Abstract Background Outbreaks of avian influenza (AI caused by infection with low pathogenic H9N2 viruses have occurred in poultry, resulting in serious economic losses in Asia and the Middle East. It has been difficult to eradicate the H9N2 virus because of its low pathogenicity, frequently causing in apparent infection. It is important for the control of AI to assess whether the H9N2 virus acquires pathogenicity as H5 and H7 viruses. In the present study, we investigated whether a non-pathogenic H9N2 virus, A/chicken/Yokohama/aq-55/2001 (Y55 (H9N2, acquires pathogenicity in chickens when a pair of di-basic amino acid residues is introduced at the cleavage site of its HA molecule. Results rgY55sub (H9N2, which had four basic amino acid residues at the HA cleavage site, replicated in MDCK cells in the absence of trypsin after six consecutive passages in the air sacs of chicks, and acquired intravenous pathogenicity to chicken after four additional passages. More than 75% of chickens inoculated intravenously with the passaged virus, rgY55sub-P10 (H9N2, died, indicating that it is pathogenic comparable to that of highly pathogenic avian influenza viruses (HPAIVs defined by World Organization for Animal Health (OIE. The chickens inoculated with the virus via the intranasal route, however, survived without showing any clinical signs. On the other hand, an avirulent H5N1 strain, A/duck/Hokkaido/Vac-1/2004 (Vac1 (H5N1, acquired intranasal pathogenicity after a pair of di-basic amino acid residues was introduced into the cleavage site of the HA, followed by two passages by air sac inoculation in chicks. Conclusion The present results demonstrate that an H9N2 virus has the potential to acquire intravenous pathogenicity in chickens although the morbidity via the nasal route of infection is lower than that of H5N1 HPAIV.

  10. Mapping DNA cleavage by the Type ISP restriction-modification enzymes following long-range communication between DNA sites in different orientations

    OpenAIRE

    van Aelst, Kara; Saikrishnan, Kayarat; Szczelkun, Mark D

    2015-01-01

    The prokaryotic Type ISP restriction-modification enzymes are single-chain proteins comprising an Mrr-family nuclease, a superfamily 2 helicase-like ATPase, a coupler domain, a methyltransferase, and a DNA-recognition domain. Upon recognising an unmodified DNA target site, the helicase-like domain hydrolyzes ATP to cause site release (remodeling activity) and to then drive downstream translocation consuming 1-2 ATP per base pair (motor activity). On an invading foreign DNA, double-strand brea...

  11. Prion Fragment Peptides Are Digested with Membrane Type Matrix Metalloproteinases and Acquire Enzyme Resistance through Cu2+-Binding

    Directory of Open Access Journals (Sweden)

    Aya Kojima

    2014-05-01

    Full Text Available Prions are the cause of neurodegenerative disease in humans and other mammals. The structural conversion of the prion protein (PrP from a normal cellular protein (PrPC to a protease-resistant isoform (PrPSc is thought to relate to Cu2+ binding to histidine residues. In this study, we focused on the membrane-type matrix metalloproteinases (MT-MMPs such as MT1-MMP and MT3-MMP, which are expressed in the brain as PrPC-degrading proteases. We synthesized 21 prion fragment peptides. Each purified peptide was individually incubated with recombinant MT1-MMP or MT3-MMP in the presence or absence of Cu2+ and the cleavage sites determined by LC-ESI-MS analysis. Recombinant MMP-7 and human serum (HS were also tested as control. hPrP61-90, from the octapeptide-repeat region, was cleaved by HS but not by the MMPs tested here. On the other hand, hPrP92-168 from the central region was cleaved by MT1-MMP and MT3-MMP at various sites. These cleavages were inhibited by treatment with Cu2+. The C-terminal peptides had higher resistance than the central region. The data obtained from this study suggest that MT-MMPs expressed in the brain might possess PrPC-degrading activity.

  12. Collagenolytic Matrix Metalloproteinase Activities toward Peptomeric Triple-Helical Substrates.

    Science.gov (United States)

    Stawikowski, Maciej J; Stawikowska, Roma; Fields, Gregg B

    2015-05-19

    Although collagenolytic matrix metalloproteinases (MMPs) possess common domain organizations, there are subtle differences in their processing of collagenous triple-helical substrates. In this study, we have incorporated peptoid residues into collagen model triple-helical peptides and examined MMP activities toward these peptomeric chimeras. Several different peptoid residues were incorporated into triple-helical substrates at subsites P3, P1, P1', and P10' individually or in combination, and the effects of the peptoid residues were evaluated on the activities of full-length MMP-1, MMP-8, MMP-13, and MMP-14/MT1-MMP. Most peptomers showed little discrimination between MMPs. However, a peptomer containing N-methyl Gly (sarcosine) in the P1' subsite and N-isobutyl Gly (NLeu) in the P10' subsite was hydrolyzed efficiently only by MMP-13 [nomenclature relative to the α1(I)772-786 sequence]. Cleavage site analysis showed hydrolysis at the Gly-Gln bond, indicating a shifted binding of the triple helix compared to the parent sequence. Favorable hydrolysis by MMP-13 was not due to sequence specificity or instability of the substrate triple helix but rather was based on the specific interactions of the P7' peptoid residue with the MMP-13 hemopexin-like domain. A fluorescence resonance energy transfer triple-helical peptomer was constructed and found to be readily processed by MMP-13, not cleaved by MMP-1 and MMP-8, and weakly hydrolyzed by MT1-MMP. The influence of the triple-helical structure containing peptoid residues on the interaction between MMP subsites and individual substrate residues may provide additional information about the mechanism of collagenolysis, the understanding of collagen specificity, and the design of selective MMP probes.

  13. Matrix Metalloproteinases Contribute to Neuronal Dysfunction in Animal Models of Drug Dependence, Alzheimer's Disease, and Epilepsy

    Directory of Open Access Journals (Sweden)

    Hiroyuki Mizoguchi

    2011-01-01

    Full Text Available Matrix metalloproteinases (MMPs and tissue inhibitors of metalloproteinases (TIMPs remodel the pericellular environment by regulating the cleavage of extracellular matrix proteins, cell surface components, neurotransmitter receptors, and growth factors that mediate cell adhesion, synaptogenesis, synaptic plasticity, and long-term potentiation. Interestingly, increased MMP activity and dysregulation of the balance between MMPs and TIMPs have also been implicated in various pathologic conditions. In this paper, we discuss various animal models that suggest that the activation of the gelatinases MMP-2 and MMP-9 is involved in pathogenesis of drug dependence, Alzheimer's disease, and epilepsy.

  14. Biochemical properties of the matrix metalloproteinase NtMMP1 from Nicotiana tabacum cv. BY-2 suspension cells.

    Science.gov (United States)

    Mandal, Manoj K; Fischer, Rainer; Schillberg, Stefan; Schiermeyer, Andreas

    2010-09-01

    A zinc-dependent matrix metalloproteinase (NtMMP1) found in the plasma membrane of Nicotiana tabacum cv. Bright Yellow 2 (BY-2) suspension cells is thought to be responsible for the degradation of recombinant proteins secreted into the culture supernatant. We have characterized the proteolytic activity of NtMMP1 by expressing a recombinant derivative lacking the C-terminal transmembrane domain in yeast. After purifying the protein by affinity chromatography, its autocatalytic activity was analyzed using monoclonal antibodies raised against its N-terminal and C-terminal portions. Both the unprocessed and processed forms of NtMMP1 displayed caseinolytic activity and N-terminal sequencing identified an autocatalytic cleavage site within the sequence motif HFSFFP, which is similar to the corresponding sequences of the human matrix metalloproteinases stromelysin-1 (MMP-3) and stromelysin-2 (MMP-10). Unlike all other matrix metalloproteinases investigated so far, NtMMP1 contains a disulfide bond within its propeptide thus rendering the proenzyme catalytically active. Kinetic analysis of NtMMP1 with a synthetic substrate revealed a K(m) of 10.55 +/- 0.9 microM, a k(cat) of 0.6 +/- 0.01 s(-1) and maximum activity at pH 7.5. We found that NtMMP1 degrades Desmodus rotundus salivary plasminogen activator alpha 1 (DSPAalpha1), a biopharmaceutical protein, that has proven difficult to produce in tobacco BY-2 cells. This provides a likely explanation for the frequent instability of secreted recombinant biopharmaceuticals produced in plant suspension cell cultures. Our data suggest new avenues that can be explored to improve the production of pharmaceutical proteins in plants and plant cells.

  15. Matrix metalloproteinases outside vertebrates.

    Science.gov (United States)

    Marino-Puertas, Laura; Goulas, Theodoros; Gomis-Rüth, F Xavier

    2017-11-01

    The matrix metalloproteinase (MMP) family belongs to the metzincin clan of zinc-dependent metallopeptidases. Due to their enormous implications in physiology and disease, MMPs have mainly been studied in vertebrates. They are engaged in extracellular protein processing and degradation, and present extensive paralogy, with 23 forms in humans. One characteristic of MMPs is a ~165-residue catalytic domain (CD), which has been structurally studied for 14 MMPs from human, mouse, rat, pig and the oral-microbiome bacterium Tannerella forsythia. These studies revealed close overall coincidence and characteristic structural features, which distinguish MMPs from other metzincins and give rise to a sequence pattern for their identification. Here, we reviewed the literature available on MMPs outside vertebrates and performed database searches for potential MMP CDs in invertebrates, plants, fungi, viruses, protists, archaea and bacteria. These and previous results revealed that MMPs are widely present in several copies in Eumetazoa and higher plants (Tracheophyta), but have just token presence in eukaryotic algae. A few dozen sequences were found in Ascomycota (within fungi) and in double-stranded DNA viruses infecting invertebrates (within viruses). In contrast, a few hundred sequences were found in archaea and >1000 in bacteria, with several copies for some species. Most of the archaeal and bacterial phyla containing potential MMPs are present in human oral and gut microbiomes. Overall, MMP-like sequences are present across all kingdoms of life, but their asymmetric distribution contradicts the vertical descent model from a eubacterial or archaeal ancestor. This article is part of a Special Issue entitled: Matrix Metalloproteinases edited by Rafael Fridman. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Capturing the Alternative Cleavage and Polyadenylation Sites of 14 NAC Genes in Populus Using a Combination of 3′-RACE and High-Throughput Sequencing

    Directory of Open Access Journals (Sweden)

    Haoran Wang

    2018-03-01

    Full Text Available Detection of complex splice sites (SSs and polyadenylation sites (PASs of eukaryotic genes is essential for the elucidation of gene regulatory mechanisms. Transcriptome-wide studies using high-throughput sequencing (HTS have revealed prevalent alternative splicing (AS and alternative polyadenylation (APA in plants. However, small-scale and high-depth HTS aimed at detecting genes or gene families are very few and limited. We explored a convenient and flexible method for profiling SSs and PASs, which combines rapid amplification of 3′-cDNA ends (3′-RACE and HTS. Fourteen NAC (NAM, ATAF1/2, CUC2 transcription factor genes of Populus trichocarpa were analyzed by 3′-RACE-seq. Based on experimental reproducibility, boundary sequence analysis and reverse transcription PCR (RT-PCR verification, only canonical SSs were considered to be authentic. Based on stringent criteria, candidate PASs without any internal priming features were chosen as authentic PASs and assumed to be PAS-rich markers. Thirty-four novel canonical SSs, six intronic/internal exons and thirty 3′-UTR PAS-rich markers were revealed by 3′-RACE-seq. Using 3′-RACE and real-time PCR, we confirmed that three APA transcripts ending in/around PAS-rich markers were differentially regulated in response to plant hormones. Our results indicate that 3′-RACE-seq is a robust and cost-effective method to discover SSs and label active regions subjected to APA for genes or gene families. The method is suitable for small-scale AS and APA research in the initial stage.

  17. Photoaffinity labeling of human serum vitamin D binding protein and chemical cleavage of the labeled protein: Identification of an 11.5-kDa peptide containing the putative 25-hydroxyvitamin D3 binding site

    International Nuclear Information System (INIS)

    Ray, R.; Holick, M.F.; Bouillon, R.; Baelen, H.V.

    1991-01-01

    In this paper, the authors describe photoaffinity labeling and related studies of human serum vitamin D binding protein (hDBP) with 25-hydroxyvitamin D 3 3β-3'-[N-(4-azido-2-nitrophenyl)amino]propyl ether (25-ANE) and its radiolabeled counterpart, i.e., 25-hydroxyvitamin D 3 3β-3'-[N-(4-azido-2-nitro-[3,5- 3 H]phenyl)amino]propyl ether ( 3 H-25-ANE). They have carried out studies to demonstrate that (1) 25-ANE competes with 25-OH-D 3 for the binding site of the latter in hDBP and (2) 3 H-25-ANE is capable of covalently labeling the hDBP molecule when exposed ot UV light. Treatment of a sample of purified hDBP, labeled with 3 H-25-ANE, with BNPS-skatole produced two Coomassie Blue stained peptide fragments, and the majority of the radioactivity was assoicated with the smaller of the two peptide fragments (16.5 kDa). On the other hand, cleavage of the labeled protein with cyanogen bromide produced a peptide (11.5 kDa) containing most of the covalently attached radioactivity. Considering the primary amino acid structure of hDBP, this peptide fragment (11.5 kDa) represents the N-terminus through residue 108 of the intact protein. Thus, the results tentatively identify this segment of the protein containing the binding pocket for 25-OH-D 3

  18. Detection of nucleic acid sequences by invader-directed cleavage

    Science.gov (United States)

    Brow, Mary Ann D.; Hall, Jeff Steven Grotelueschen; Lyamichev, Victor; Olive, David Michael; Prudent, James Robert

    1999-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The 5' nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof. The present invention further relates to methods and devices for the separation of nucleic acid molecules based by charge.

  19. Intermolecular cleavage by UmuD-like mutagenesis proteins

    Science.gov (United States)

    McDonald, John P.; Frank, Ekaterina G.; Levine, Arthur S.; Woodgate, Roger

    1998-01-01

    The activity of a number of proteins is regulated by self-processing reactions. Elegant examples are the cleavage of the prokaryotic LexA and λCI transcriptional repressors and the UmuD-like mutagenesis proteins. Various studies support the hypothesis that LexA and λCI cleavage reactions are predominantly intramolecular in nature. The recently described crystal structure of the Escherichia coli UmuD′ protein (the posttranslational cleavage product of the UmuD protein) suggests, however, that the region of the protein corresponding to the cleavage site is at least 50 Å away from the catalytic active site. We considered the possibility, therefore, that the UmuD-like proteins might undergo self-processing that, in contrast to LexA and λCI, occurs via an intermolecular rather than intramolecular reaction. To test this hypothesis, we introduced into E. coli compatible plasmids with mutations at either the cleavage or the catalytic site of three UmuD-like proteins. Cleavage of these proteins only occurs in the presence of both plasmids, indicating that the reaction is indeed intermolecular in nature. Furthermore, this intermolecular reaction is completely dependent upon the multifunctional RecA protein and leads to the restoration of cellular mutagenesis in nonmutable E. coli strains. Intermolecular cleavage of a biotinylated UmuD active site mutant was also observed in vitro in the presence of the wild-type UmuD′ protein, indicating that in addition to the intact UmuD protein, the normal cleavage product (UmuD′) can also act as a classical enzyme. PMID:9465040

  20. Prediction of proprotein convertase cleavage sites

    DEFF Research Database (Denmark)

    Duckert, Peter; Brunak, Søren; Blom, Nikolaj

    2004-01-01

    by members of the subtilisin/kexin-like proprotein convertase (PC) family. In mammals, seven members have been identified, with furin being the one first discovered and best characterized. Recently, the involvement of furin in diseases ranging from Alzheimer's disease and cancer to anthrax and Ebola fever...

  1. Vertebrate Embryonic Cleavage Pattern Determination.

    Science.gov (United States)

    Hasley, Andrew; Chavez, Shawn; Danilchik, Michael; Wühr, Martin; Pelegri, Francisco

    2017-01-01

    The pattern of the earliest cell divisions in a vertebrate embryo lays the groundwork for later developmental events such as gastrulation, organogenesis, and overall body plan establishment. Understanding these early cleavage patterns and the mechanisms that create them is thus crucial for the study of vertebrate development. This chapter describes the early cleavage stages for species representing ray-finned fish, amphibians, birds, reptiles, mammals, and proto-vertebrate ascidians and summarizes current understanding of the mechanisms that govern these patterns. The nearly universal influence of cell shape on orientation and positioning of spindles and cleavage furrows and the mechanisms that mediate this influence are discussed. We discuss in particular models of aster and spindle centering and orientation in large embryonic blastomeres that rely on asymmetric internal pulling forces generated by the cleavage furrow for the previous cell cycle. Also explored are mechanisms that integrate cell division given the limited supply of cellular building blocks in the egg and several-fold changes of cell size during early development, as well as cytoskeletal specializations specific to early blastomeres including processes leading to blastomere cohesion. Finally, we discuss evolutionary conclusions beginning to emerge from the contemporary analysis of the phylogenetic distributions of cleavage patterns. In sum, this chapter seeks to summarize our current understanding of vertebrate early embryonic cleavage patterns and their control and evolution.

  2. Sequence specific inhibition of DNA restriction enzyme cleavage by PNA

    DEFF Research Database (Denmark)

    Nielsen, P.E.; Egholm, M.; Berg, R.H.

    1993-01-01

    Plasmids containing double-stranded 10-mer PNA (peptide nucleic acid chimera) targets proximally flanked by two restriction enzyme sites were challenged with the complementary PNA or PNAs having one or two mismatches, and the effect on the restriction enzyme cleavage of the flanking sites was ass...

  3. Matrix Metalloproteinase Responsive Delivery of Myostatin Inhibitors.

    Science.gov (United States)

    Braun, Alexandra C; Gutmann, Marcus; Ebert, Regina; Jakob, Franz; Gieseler, Henning; Lühmann, Tessa; Meinel, Lorenz

    2017-01-01

    The inhibition of myostatin - a member of the transforming growth factor (TGF-β) family - drives regeneration of functional skeletal muscle tissue. We developed a bioresponsive drug delivery system (DDS) linking release of a myostatin inhibitor (MI) to inflammatory flares of myositis to provide self-regulated MI concentration gradients within tissues of need. A protease cleavable linker (PCL) - responding to MMP upregulation - is attached to the MI and site-specifically immobilized on microparticle surfaces. The PCL disintegrated in a matrix metalloproteinase (MMP) 1, 8, and particularly MMP-9 concentration dependent manner, with MMP-9 being an effective surrogate biomarker correlating with the activity of myositis. The bioactivity of particle-surface bound as well as released MI was confirmed by luciferase suppression in stably transfected HEK293 cells responding to myostatin induced SMAD phosphorylation. We developed a MMP-responsive DDS for MI delivery responding to inflammatory flare of a diseased muscle matching the kinetics of MMP-9 upregulation, with MMP-9 kinetics matching (patho-) physiological myostatin levels. ᅟ: Graphical Abstract Schematic illustration of the matrix metalloproteinase responsive delivery system responding to inflammatory flares of muscle disease. The protease cleavable linker readily disintegrates upon entry into the diseased tissue, therby releasing the mystatin inhibitor.

  4. Prediction of proteasome cleavage motifs by neural networks

    DEFF Research Database (Denmark)

    Kesimir, C.; Nussbaum, A.K.; Schild, H.

    2002-01-01

    physiological conditions. Our algorithm has been trained not only on in vitro data, but also on MHC Class I ligand data, which reflect a combination of immunoproteasome and constitutive proteasome specificity. This feature, together with the use of neural networks, a non-linear classification technique, make...... the prediction of MHC Class I ligand boundaries more accurate: 65% of the cleavage sites and 85% of the non-cleavage sites are correctly determined. Moreover, we show that the neural networks trained on the constitutive proteasome data learns a specificity that differs from that of the networks trained on MHC...

  5. Ramiprilate inhibits functional matrix metalloproteinase activity in Crohn's disease fistulas

    DEFF Research Database (Denmark)

    Efsen, Eva; Saermark, Torben; Hansen, Alastair

    2011-01-01

    Increased expression of matrix metalloproteinase (MMP)-2, -3 and -9 has been demonstrated in Crohn's disease fistulas, but it is unknown whether these enzymes are biologically active and represent a therapeutic target. Therefore, we investigated the proteolytic activity of MMPs in fistula tissue...... from six controls were also included. Total functional MMP activity was measured by a high-pressure liquid chromatography (HPLC)-based, fluorogenic MMP-substrate cleavage assay, and the specific activity of MMP-2, -3 and -9 by the MMP Biotrak Activity Assay. The MMP inhibitors comprised ethylene......-9.83) compared with non-Crohn's fistulas, [0.32 ng/ml, range 0-2.66, (p MMP-9 activity [0.64 ng/ml, range 0-5.66 and 0.17 ng/ml, range 0-1.1, respectively (p MMP activity level by 42% and suppressed the specific MMP-3...

  6. Structural properties of matrix metalloproteinases.

    Science.gov (United States)

    Bode, W; Fernandez-Catalan, C; Tschesche, H; Grams, F; Nagase, H; Maskos, K

    1999-04-01

    Matrix metalloproteinases (MMPs) are involved in extracellular matrix degradation. Their proteolytic activity must be precisely regulated by their endogenous protein inhibitors, the tissue inhibitors of metalloproteinases (TIMPs). Disruption of this balance results in serious diseases such as arthritis, tumour growth and metastasis. Knowledge of the tertiary structures of the proteins involved is crucial for understanding their functional properties and interference with associated dysfunctions. Within the last few years, several three-dimensional MMP and MMP-TIMP structures became available, showing the domain organization, polypeptide fold and main specificity determinants. Complexes of the catalytic MMP domains with various synthetic inhibitors enabled the structure-based design and improvement of high-affinity ligands, which might be elaborated into drugs. A multitude of reviews surveying work done on all aspects of MMPs have appeared in recent years, but none of them has focused on the three-dimensional structures. This review was written to close the gap.

  7. Circulating levels of matrix metalloproteinases and tissue inhibitors of metalloproteinases in patients with incisional hernia

    DEFF Research Database (Denmark)

    Henriksen, Nadia A; Sørensen, Lars T; Jorgensen, Lars N

    2013-01-01

    Incisional hernia formation is a common complication to laparotomy and possibly associated with alterations in connective tissue metabolism. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are closely involved in the metabolism of the extracellular matrix. Our...

  8. Matrix metalloproteinase-9-mediated type III collagen degradation as a novel serological biochemical marker for liver fibrogenesis

    DEFF Research Database (Denmark)

    Veidal, Sanne S; Vassiliadis, Efstathios; Barascuk, Natasha

    2010-01-01

    During fibrogenesis in the liver, in which excessive remodelling of the extracellular matrix (ECM) occurs, both the quantity of type III collagen (CO3) and levels of matrix metalloproteinases (MMPs), including MMP-9, increase significantly. MMPs play major roles in ECM remodelling, via...... their activity in the proteolytic degradation of extracellular macromolecules such as collagens, resulting in the generation of specific cleavage fragments. These neo-epitopes may be used as markers of fibrosis....

  9. Cleavage of desmin by cysteine proteases: Calpains and cathepsin B

    DEFF Research Database (Denmark)

    Baron, Caroline; Jacobsen, S.; Purslow, P.P.

    2004-01-01

    The intermediate filament protein, desmin, was purified from pork longissimus dorsi and incubated with either P-calpain, m-calpain or cathepsin B. Proteolysis of desmin was followed using SDS-PAGE and Western blotting. After incubation of desmin with the proteases, cleavage sites on the desmin mo...

  10. Unexpected tolerance of alpha-cleavage of the prion protein to sequence variations.

    Directory of Open Access Journals (Sweden)

    José B Oliveira-Martins

    Full Text Available The cellular form of the prion protein, PrP(C, undergoes extensive proteolysis at the alpha site (109K [see text]H110. Expression of non-cleavable PrP(C mutants in transgenic mice correlates with neurotoxicity, suggesting that alpha-cleavage is important for PrP(C physiology. To gain insights into the mechanisms of alpha-cleavage, we generated a library of PrP(C mutants with mutations in the region neighbouring the alpha-cleavage site. The prevalence of C1, the carboxy adduct of alpha-cleavage, was determined for each mutant. In cell lines of disparate origin, C1 prevalence was unaffected by variations in charge and hydrophobicity of the region neighbouring the alpha-cleavage site, and by substitutions of the residues in the palindrome that flanks this site. Instead, alpha-cleavage was size-dependently impaired by deletions within the domain 106-119. Almost no cleavage was observed upon full deletion of this domain. These results suggest that alpha-cleavage is executed by an alpha-PrPase whose activity, despite surprisingly limited sequence specificity, is dependent on the size of the central region of PrP(C.

  11. Short RNA guides cleavage by eukaryotic RNase III.

    Directory of Open Access Journals (Sweden)

    Bruno Lamontagne

    Full Text Available In eukaryotes, short RNAs guide a variety of enzymatic activities that range from RNA editing to translation repression. It is hypothesized that pre-existing proteins evolved to bind and use guide RNA during evolution. However, the capacity of modern proteins to adopt new RNA guides has never been demonstrated. Here we show that Rnt1p, the yeast orthologue of the bacterial dsRNA-specific RNase III, can bind short RNA transcripts and use them as guides for sequence-specific cleavage. Target cleavage occurred at a constant distance from the Rnt1p binding site, leaving the guide RNA intact for subsequent cleavage. Our results indicate that RNase III may trigger sequence-specific RNA degradation independent of the RNAi machinery, and they open the road for a new generation of precise RNA silencing tools that do not trigger a dsRNA-mediated immune response.

  12. Metalloproteinases and their regulators in colorectal cancer.

    NARCIS (Netherlands)

    Jagt, M.F.P. van der; Wobbes, T.; Strobbe, L.J.; Sweep, F.C.; Span, P.N.

    2010-01-01

    Metalloproteinases (MPs) such as the matrix metalloproteinases (MMPs) and adamalysins (ADAMs and ADAMTS) are expressed in various stages of colorectal cancer (CRC), and some correlate with survival and prognosis. The MPs are regulated by various factors including EMMPRIN, TIMPs, and RECK. In

  13. Flanking signal and mature peptide residues influence signal peptide cleavage

    Directory of Open Access Journals (Sweden)

    Ranganathan Shoba

    2008-12-01

    Full Text Available Abstract Background Signal peptides (SPs mediate the targeting of secretory precursor proteins to the correct subcellular compartments in prokaryotes and eukaryotes. Identifying these transient peptides is crucial to the medical, food and beverage and biotechnology industries yet our understanding of these peptides remains limited. This paper examines the most common type of signal peptides cleavable by the endoprotease signal peptidase I (SPase I, and the residues flanking the cleavage sites of three groups of signal peptide sequences, namely (i eukaryotes (Euk (ii Gram-positive (Gram+ bacteria, and (iii Gram-negative (Gram- bacteria. Results In this study, 2352 secretory peptide sequences from a variety of organisms with amino-terminal SPs are extracted from the manually curated SPdb database for analysis based on physicochemical properties such as pI, aliphatic index, GRAVY score, hydrophobicity, net charge and position-specific residue preferences. Our findings show that the three groups share several similarities in general, but they display distinctive features upon examination in terms of their amino acid compositions and frequencies, and various physico-chemical properties. Thus, analysis or prediction of their sequences should be separated and treated as distinct groups. Conclusion We conclude that the peptide segment recognized by SPase I extends to the start of the mature protein to a limited extent, upon our survey of the amino acid residues surrounding the cleavage processing site. These flanking residues possibly influence the cleavage processing and contribute to non-canonical cleavage sites. Our findings are applicable in defining more accurate prediction tools for recognition and identification of cleavage site of SPs.

  14. Detection of functional matrix metalloproteinases by zymography.

    Science.gov (United States)

    Hu, Xueyou; Beeton, Christine

    2010-11-08

    Matrix metalloproteinases (MMPs) are zinc-containing endopeptidases. They degrade proteins by cleavage of peptide bonds. More than twenty MMPs have been identified and are separated into six groups based on their structure and substrate specificity (collagenases, gelatinases, membrane type [MT-MMP], stromelysins, matrilysins, and others). MMPs play a critical role in cell invasion, cartilage degradation, tissue remodeling, wound healing, and embryogenesis. They therefore participate in both normal processes and in the pathogenesis of many diseases, such as rheumatoid arthritis, cancer, or chronic obstructive pulmonary disease. Here, we will focus on MMP-2 (gelatinase A, type IV collagenase), a widely expressed MMP. We will demonstrate how to detect MMP-2 in cell culture supernatants by zymography, a commonly used, simple, and yet very sensitive technique first described in 1980 by C. Heussen and E.B. Dowdle. This technique is semi-quantitative, it can therefore be used to determine MMP levels in test samples when known concentrations of recombinant MMP are loaded on the same gel. Solutions containing MMPs (e.g. cell culture supernatants, urine, or serum) are loaded onto a polyacrylamide gel containing sodium dodecyl sulfate (SDS; to linearize the proteins) and gelatin (substrate for MMP-2). The sample buffer is designed to increase sample viscosity (to facilitate gel loading), provide a tracking dye (bromophenol blue; to monitor sample migration), provide denaturing molecules (to linearize proteins), and control the pH of the sample. Proteins are then allowed to migrate under an electric current in a running buffer designed to provide a constant migration rate. The distance of migration is inversely correlated with the molecular weight of the protein (small proteins move faster through the gel than large proteins do and therefore migrate further down the gel). After migration, the gel is placed in a renaturing buffer to allow proteins to regain their tertiary

  15. Post-transcription cleavage generates the 3' end of F17R transcripts in vaccinia virus

    International Nuclear Information System (INIS)

    D'Costa, Susan M.; Antczak, James B.; Pickup, David J.; Condit, Richard C.

    2004-01-01

    Most vaccinia virus intermediate and late mRNAs possess 3' ends that are extremely heterogeneous in sequence. However, late mRNAs encoding the cowpox A-type inclusion protein (ATI), the second largest subunit of the RNA polymerase, and the late telomeric transcripts possess homogeneous 3' ends. In the case of the ATI mRNA, it has been shown that the homogeneous 3' end is generated by a post-transcriptional endoribonucleolytic cleavage event. We have determined that the F17R gene also produces homogeneous transcripts generated by a post-transcriptional cleavage event. Mapping of in vivo mRNA shows that the major 3' end of the F17R transcript maps 1262 nt downstream of the F17R translational start site. In vitro transcripts spanning the in vivo 3' end are cleaved in an in vitro reaction using extracts from virus infected cells, and the site of cleavage is the same both in vivo and in vitro. Cleavage is not observed using extract from cells infected in the presence of hydroxyurea; therefore, the cleavage factor is either virus-coded or virus-induced during the post-replicative phase of virus replication. The cis-acting sequence responsible for cleavage is orientation specific and the factor responsible for cleavage activity has biochemical properties similar to the factor required for cleavage of ATI transcripts. Partially purified cleavage factor generates cleavage products of expected size when either the ATI or F17R substrates are used in vitro, strongly suggesting that cleavage of both transcripts is mediated by the same factor

  16. Matrix metalloproteinases in lung biology

    Directory of Open Access Journals (Sweden)

    Parks William C

    2000-12-01

    Full Text Available Abstract Despite much information on their catalytic properties and gene regulation, we actually know very little of what matrix metalloproteinases (MMPs do in tissues. The catalytic activity of these enzymes has been implicated to function in normal lung biology by participating in branching morphogenesis, homeostasis, and repair, among other events. Overexpression of MMPs, however, has also been blamed for much of the tissue destruction associated with lung inflammation and disease. Beyond their role in the turnover and degradation of extracellular matrix proteins, MMPs also process, activate, and deactivate a variety of soluble factors, and seldom is it readily apparent by presence alone if a specific proteinase in an inflammatory setting is contributing to a reparative or disease process. An important goal of MMP research will be to identify the actual substrates upon which specific enzymes act. This information, in turn, will lead to a clearer understanding of how these extracellular proteinases function in lung development, repair, and disease.

  17. Structural differences of matrix metalloproteinases. Homology modeling and energy minimization of enzyme-substrate complexes

    DEFF Research Database (Denmark)

    Terp, G E; Christensen, I T; Jørgensen, Flemming Steen

    2000-01-01

    Matrix metalloproteinases are extracellular enzymes taking part in the remodeling of extracellular matrix. The structures of the catalytic domain of MMP1, MMP3, MMP7 and MMP8 are known, but structures of enzymes belonging to this family still remain to be determined. A general approach...... to the homology modeling of matrix metalloproteinases, exemplified by the modeling of MMP2, MMP9, MMP12 and MMP14 is described. The models were refined using an energy minimization procedure developed for matrix metalloproteinases. This procedure includes incorporation of parameters for zinc and calcium ions...... in the AMBER 4.1 force field, applying a non-bonded approach and a full ion charge representation. Energy minimization of the apoenzymes yielded structures with distorted active sites, while reliable three-dimensional structures of the enzymes containing a substrate in active site were obtained. The structural...

  18. Correlation between matrix metalloproteinase-9 and endometriosis.

    Science.gov (United States)

    Liu, Haiping; Wang, Jianye; Wang, Haiyu; Tang, Ning; Li, Yunfei; Zhang, Yan; Hao, Tianyu

    2015-01-01

    Endometrial implantation is the major cause of endometriosis (EMS). Matrix metalloproteinase (MMPs) can degrade multiple extracellular matrix and has been postulated to be related with EMC occurrence. This study thus investigated serum and ascites levels of MMP-9 in EMS patients, in an attempt to discuss the correlation between MMP-9 and EMS. A total of 100 EMS patients, including eutopic endometrium and ectopic endometrium, were recruited in this study along with hysteromyoma patients as the control group. Peripheral blood and ascites samples were collected and tested for MMP-9 levels using gelatin zymogram and enzyme-linked immunosorbent assay (ELISA). In EMS patients, MMP-9 levels in serum and ascites were 6.24 ± 0.53 mM and 38.57 ± 4.93 mM, respectively. Both of them were significantly higher than those in control group (P<0.05). Eutopic endometrium group had higher MMP-9 levels compared to those in ectopic endometrium ones (P<0.05). With advancement of disease stage, EMS patients had progressively elevated MMP-9 levels (P<0.05). Patients at proliferative stage had higher MMP-9 secretion (P<0.05). In summary, site of endometrium, clinical stage and proliferative cycle were independent risk factors for EMS. The elevation of serum and ascites MMP-9 existed in EMS patients, of which those had ectopic endometrium, advanced stage and at proliferative stage had higher MMP-9 expression.

  19. Matrix metalloproteinases: structures, evolution, and diversification.

    Science.gov (United States)

    Massova, I; Kotra, L P; Fridman, R; Mobashery, S

    1998-09-01

    A comprehensive sequence alignment of 64 members of the family of matrix metalloproteinases (MMPs) for the entire sequences, and subsequently the catalytic and the hemopexin-like domains, have been performed. The 64 MMPs were selected from plants, invertebrates, and vertebrates. The analyses disclosed that as many as 23 distinct subfamilies of these proteins are known to exist. Information from the sequence alignments was correlated with structures, both crystallographic as well as computational, of the catalytic domains for the 23 representative members of the MMP family. A survey of the metal binding sites and two loops containing variable sequences of amino acids, which are important for substrate interactions, are discussed. The collective data support the proposal that the assembly of the domains into multidomain enzymes was likely to be an early evolutionary event. This was followed by diversification, perhaps in parallel among the MMPs, in a subsequent evolutionary time scale. Analysis indicates that a retrograde structure simplification may have accounted for the evolution of MMPs with simple domain constituents, such as matrilysin, from the larger and more elaborate enzymes.

  20. EMMPRIN Modulates Epithelial Barrier Function through a MMP–Mediated Occludin Cleavage

    Science.gov (United States)

    Huet, Eric; Vallée, Benoit; Delbé, Jean; Mourah, Samia; Prulière-Escabasse, Virginie; Tremouilleres, Magali; Kadomatsu, Kenji; Doan, Serge; Baudouin, Christophe; Menashi, Suzanne; Gabison, Eric E.

    2011-01-01

    Dry eye is a common disease that develops as a result of alteration of tear fluid, leading to osmotic stress and a perturbed epithelial barrier. Matrix metalloproteinase-9 (MMP-9) may be important in dry eye disease, as its genetic knockout conferred resistance to the epithelial disruption. We show that extracellular matrix metalloproteinase inducer (EMMPRIN; also termed CD147), an inducer of MMP expression, participates in the pathogenesis of dry eye through MMP-mediated cleavage of occludin, an important component of tight junctions. EMMPRIN expression was increased on the ocular surface of dry eye patients and correlated with those of MMP-9. High osmolarity in cell culture, mimicking dry eye conditions, increased both EMMPRIN and MMP-9 and resulted in the disruption of epithelial junctions through the cleavage of occludin. Exogenously added recombinant EMMPRIN had similar effects that were abrogated in the presence of the MMP inhibitor marimastat. Membrane occludin immunostaining was markedly increased in the apical corneal epithelium of both EMMPRIN and MMP-9 knock-out mice. Furthermore, an inverse correlation between EMMPRIN and occludin membrane staining was consistently observed both in vitro and in vivo as a function of corneal epithelial cells differentiation. These data suggest a possible role of EMMPRIN in regulating the amount of occludin at the cell surface in homeostasis beyond pathological situations such as dry eye disease, and EMMPRIN may be essential for the formation and maintenance of organized epithelial structure. PMID:21777561

  1. Matrix metalloproteinase 9 (MMP-9) mediated release of MMP-9 resistant stromal cell-derived factor 1α (SDF-1α) from surface modified polymer films.

    Science.gov (United States)

    Steinhagen, Max; Hoffmeister, Peter-Georg; Nordsieck, Karoline; Hötzel, Rudi; Baumann, Lars; Hacker, Michael C; Schulz-Siegmund, Michaela; Beck-Sickinger, Annette G

    2014-04-23

    Preparation of smart materials by coatings of established surfaces with biomolecules will lead to the next generation of functionalized biomaterials. Rejection of implants is still a major problem in medical applications but masking the implant material with protein coatings is a promising approach. These layers not only disguise the material but also equip it with a certain biological function. The anti-inflammatory chemokine stromal cell-derived factor 1α (SDF-1α) is well suited to take over this function, because it efficiently attracts stem cells and promotes their differentiation and proliferation. At least the initial stem cell homing requires the formation of a concentration gradient. Thus, a reliable and robust release mechanism of SDF-1α from the material is essential. Several proteases, most notably matrix metalloproteinases, are upregulated during inflammation, which, in principle, can be exploited for a tightly controlled release of SDF-1α. Herein, we present the covalent immobilization of M-[S4V]-SDF-1α on novel biodegradable polymer films, which consist of heterobifunctional poly(ethylene glycol) and oligolactide-based functionalized macromers. A peptidic linker with a trimeric matrix metalloproteinase 9 (MMP-9) cleavage site (MCS) was used as connection and the linkage between the three components was achieved by combination of expressed protein ligation and Cu(I) catalyzed azide/alkyne cycloaddition. The MCS was used for MMP-9 mediated release of M-[S4V]-SDF-1α from the biomaterial and the released SDF-1α derivative was biologically active and induced strong cell migration, which demonstrates the great potential of this system.

  2. Acrolein-activated matrix metalloproteinase 9 contributes to persistent mucin production.

    Science.gov (United States)

    Deshmukh, Hitesh S; Shaver, Colleen; Case, Lisa M; Dietsch, Maggie; Wesselkamper, Scott C; Hardie, William D; Korfhagen, Thomas R; Corradi, Massimo; Nadel, Jay A; Borchers, Michael T; Leikauf, George D

    2008-04-01

    Chronic obstructive pulmonary disease (COPD), a global public health problem, is characterized by progressive difficulty in breathing, with increased mucin production, especially in the small airways. Acrolein, a constituent of cigarette smoke and an endogenous mediator of oxidative stress, increases airway mucin 5, subtypes A and C (MUC5AC) production; however, the mechanism remains unclear. In this study, increased mMUC5AC transcripts and protein were associated with increased lung matrix metalloproteinase 9 (mMMP9) transcripts, protein, and activity in acrolein-exposed mice. Increased mMUC5AC transcripts and mucin protein were diminished in gene-targeted Mmp9 mice [Mmp9((-/-))] or in mice treated with an epidermal growth factor receptor (EGFR) inhibitor, erlotinib. Acrolein also decreased mTissue inhibitor of metalloproteinase protein 3 (an MMP9 inhibitor) transcript levels. In a cell-free system, acrolein increased pro-hMMP9 cleavage and activity in concentrations (100-300 nM) found in sputum from subjects with COPD. Acrolein increased hMMP9 transcripts in human airway cells, which was inhibited by an MMP inhibitor, EGFR-neutralizing antibody, or a mitogen-activated protein kinase (MAPK) 3/2 inhibitor. Together these findings indicate that acrolein can initiate cleavage of pro-hMMP9 and EGFR/MAPK signaling that leads to additional MMP9 formation. Augmentation of hMMP9 activity, in turn, could contribute to persistent excessive mucin production.

  3. Glutamic Acid Selective Chemical Cleavage of Peptide Bonds.

    Science.gov (United States)

    Nalbone, Joseph M; Lahankar, Neelam; Buissereth, Lyssa; Raj, Monika

    2016-03-04

    Site-specific hydrolysis of peptide bonds at glutamic acid under neutral aqueous conditions is reported. The method relies on the activation of the backbone amide chain at glutamic acid by the formation of a pyroglutamyl (pGlu) imide moiety. This activation increases the susceptibility of a peptide bond toward hydrolysis. The method is highly specific and demonstrates broad substrate scope including cleavage of various bioactive peptides with unnatural amino acid residues, which are unsuitable substrates for enzymatic hydrolysis.

  4. The effect of tomatine on metastasis related matrix metalloproteinase (MMP) activities in breast cancer cell model.

    Science.gov (United States)

    Yelken, Besra Özmen; Balcı, Tuğçe; Süslüer, Sunde Yılmaz; Kayabaşı, Çağla; Avcı, Çığır Biray; Kırmızıbayrak, Petek Ballar; Gündüz, Cumhur

    2017-09-05

    Breast cancer is one of the most common malignancies in women and metastasis is the cause of morbidity and mortality in patients. In the development of metastasis, the matrix metalloproteinase (MMP) family has a very important role in tumor development. MMP-2 and MMP-9 work together for extracellular matrix (ECM) cleavage to increase migration. Tomatine is a secondary metabolite that has a natural defense role against plants, fungi, viruses and bacteria that are synthesized from tomato. In additıon, tomatine is also known that it breaks down the cell membrane and is a strong inhibitor in human cancer cells. In this study, it was aimed to evaluate the effect of tomatine on cytotoxicity, apoptosis and matrix metalloproteinase inhibition in MCF-7 cell lines. Human breast cancer cell line (MCF-7) was used as a cell line. In MCF-7 cells, the IC 50 dose of tomatine was determined to be 7.07μM. According to the control cells, apoptosis increased 3.4 fold in 48thh. Activation of MMP-2, MMP-9 and MMP-9\\NGAL has been shown to decrease significantly in cells treated with tomatine by gelatin zymography compared to the control. As a result, matrix metalloproteinase activity and cell proliferation were suppressed by tomatine and this may provide support in treatment methods. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Matrix metalloproteinases and tissue inhibitors of metalloproteinases in gingival crevicular fluid during orthodontic tooth movement.

    NARCIS (Netherlands)

    Bildt, M.M.; Bloemen, M.; Kuijpers-Jagtman, A.M.; Hoff, J.W. Von den

    2009-01-01

    Orthodontic tooth movement requires extensive re-modelling of the periodontium. Matrix metalloproteinases (MMPs) degrade the extracellular matrix during re-modelling, while their activity is regulated by the tissue inhibitors of metalloproteinases (TIMPs). The aim of this study was to investigate

  6. Matrix metalloproteinases and tissue inhibitors of metalloproteinases in gingival crevicular fluid during orthodontic tooth movement

    NARCIS (Netherlands)

    Bildt, Miriam; Bloemen, M; Kuijpers-Jagtman, A.M.; Von Den Hoff, Johannes W

    2009-01-01

    Orthodontic tooth movement requires extensive re-modelling of the periodontium. Matrix metalloproteinases (MMPs) degrade the extracellular matrix during re-modelling, while their activity is regulated by the tissue inhibitors of metalloproteinases (TIMPs). The aim of this study was to investigate

  7. Cleavage and creep fracture of rock salt

    International Nuclear Information System (INIS)

    Chan, K.S.; Munson, D.E.; Bodner, S.R.

    1996-01-01

    The dominant failure mechanism in rock salt at ambient temperature is either cleavage or creep fracture. Since the transition of creep fracture to cleavage in a compressive stress field is not well understood, failure of rock salt by cleavage and creep fracture is analyzed in this paper to elucidate the effect of stress state on the competition between these two fracture mechanisms. For cleavage fracture, a shear crack is assumed to cause the formation and growth of a symmetric pair of wing cracks in a predominantly compressive stress field. The conditions for wing-crack instability are derived and presented as the cleavage fracture boundary in the fracture mechanism map. Using an existing creep fracture model, stress conditions for the onset of creep fracture and isochronous failure curves of specified times-to-rupture are calculated and incorporated into the fracture mechanism map. The regimes of dominance by cleavage and creep fracture are established and compared with experimental data. The result indicates that unstable propagation of cleavage cracks occurs only in the presence of tensile stress. The onset of creep fracture is promoted by a tensile stress, but can be totally suppressed by a high confining pressure. Transition of creep fracture to cleavage occurs when critical conditions of stress difference and tensile stress for crack instability are exceeded

  8. Microstructure and cleavage in lath martensitic steels

    International Nuclear Information System (INIS)

    Morris, John W Jr; Kinney, Chris; Pytlewski, Ken; Adachi, Y

    2013-01-01

    In this paper we discuss the microstructure of lath martensitic steels and the mechanisms by which it controls cleavage fracture. The specific experimental example is a 9Ni (9 wt% Ni) steel annealed to have a large prior austenite grain size, then examined and tested in the as-quenched condition to produce a relatively coarse lath martensite. The microstructure is shown to approximate the recently identified ‘classic’ lath martensite structure: prior austenite grains are divided into packets, packets are subdivided into blocks, and blocks contain interleaved laths whose variants are the two Kurjumov–Sachs relations that share the same Bain axis of the transformation. When the steel is fractured in brittle cleavage, the laths in the block share {100} cleavage planes and cleave as a unit. However, cleavage cracks deflect or blunt at the boundaries between blocks with different Bain axes. It follows that, as predicted, the block size governs the effective grain size for cleavage. (paper)

  9. Downstream element determines RNase Y cleavage of the saePQRS operon in Staphylococcus aureus.

    Science.gov (United States)

    Marincola, Gabriella; Wolz, Christiane

    2017-06-02

    In gram-positive bacteria, RNase J1, RNase J2 and RNase Y are thought to be major contributors to mRNA degradation and maturation. In Staphylococcus aureus, RNase Y activity is restricted to regulating the mRNA decay of only certain transcripts. Here the saePQRS operon was used as a model to analyze RNase Y specificity in living cells. A RNase Y cleavage site is located in an intergenic region between saeP and saeQ. This cleavage resulted in rapid degradation of the upstream fragment and stabilization of the downstream fragment. Thereby, the expression ratio of the different components of the operon was shifted towards saeRS, emphasizing the regulatory role of RNase Y activity. To assess cleavage specificity different regions surrounding the sae CS were cloned upstream of truncated gfp, and processing was analyzed in vivo using probes up- and downstream of CS. RNase Y cleavage was not determined by the cleavage site sequence. Instead a 24-bp double-stranded recognition structure was identified that was required to initiate cleavage 6 nt upstream. The results indicate that RNase Y activity is determined by secondary structure recognition determinants, which guide cleavage from a distance. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  10. Fluorescent Water Soluble Polymers for Isozyme-Selective Interactions with Matrix Metalloproteinase-9

    Science.gov (United States)

    Dutta, Rinku; Scott, Michael D.; Haldar, Manas K.; Ganguly, Bratati; Srivastava, D. K.; Friesner, Daniel L.; Mallik, Sanku

    2011-01-01

    Matrix metalloproteinases (MMPs) are overexpressed in various pathological conditions, including various cancers. Although these isozymes have similar active sites, the patterns of exposed amino acids on their surfaces are different. Herein, we report the synthesis and molecular interactions of two water-soluble, fluorescent polymers which demonstrate selective interactions with MMP-9 compared to MMP-7 and -10. PMID:21367603

  11. Structure of matrix metalloproteinase-3 with a platinum-based inhibitor.

    Science.gov (United States)

    Belviso, Benny Danilo; Caliandro, Rocco; Siliqi, Dritan; Calderone, Vito; Arnesano, Fabio; Natile, Giovanni

    2013-06-18

    An X-ray investigation has been performed with the aim of characterizing the binding sites of a platinum-based inhibitor (K[PtCl3(DMSO)]) of matrix metalloproteinase-3 (stromelysin-1). The platinum complex targets His224 in the S1' specificity loop, representing the first step in the selective inhibition process (PDB ID code 4JA1).

  12. Cleavage and Cell Adhesion Properties of Human Epithelial Cell Adhesion Molecule (HEPCAM)*

    Science.gov (United States)

    Tsaktanis, Thanos; Kremling, Heidi; Pavšič, Miha; von Stackelberg, Ricarda; Mack, Brigitte; Fukumori, Akio; Steiner, Harald; Vielmuth, Franziska; Spindler, Volker; Huang, Zhe; Jakubowski, Jasmine; Stoecklein, Nikolas H.; Luxenburger, Elke; Lauber, Kirsten; Lenarčič, Brigita; Gires, Olivier

    2015-01-01

    Human epithelial cell adhesion molecule (HEPCAM) is a tumor-associated antigen frequently expressed in carcinomas, which promotes proliferation after regulated intramembrane proteolysis. Here, we describe extracellular shedding of HEPCAM at two α-sites through a disintegrin and metalloprotease (ADAM) and at one β-site through BACE1. Transmembrane cleavage by γ-secretase occurs at three γ-sites to generate extracellular Aβ-like fragments and at two ϵ-sites to release human EPCAM intracellular domain HEPICD, which is efficiently degraded by the proteasome. Mapping of cleavage sites onto three-dimensional structures of HEPEX cis-dimer predicted conditional availability of α- and β-sites. Endocytosis of HEPCAM warrants acidification in cytoplasmic vesicles to dissociate protein cis-dimers required for cleavage by BACE1 at low pH values. Intramembrane cleavage sites are accessible and not part of the structurally important transmembrane helix dimer crossing region. Surprisingly, neither chemical inhibition of cleavage nor cellular knock-out of HEPCAM using CRISPR-Cas9 technology impacted the adhesion of carcinoma cell lines. Hence, a direct function of HEPCAM as an adhesion molecule in carcinoma cells is not supported and appears to be questionable. PMID:26292218

  13. Characterization of SNARE Cleavage Products Generated by Formulated Botulinum Neurotoxin Type-A Drug Products

    Directory of Open Access Journals (Sweden)

    Jack Xie

    2010-08-01

    Full Text Available The study evaluated substrate cleavage product(s generated by three botulinum neurotoxin serotype A (BoNT/A medicinal drug products utilizing a novel and highly specific, light-chain activity, high-performance liquid chromatography (LCA-HPLC method. Samples were reacted with a commercially available BoNT/A fluorescent substrate derived from the SNAP-25 sequence. Reaction products were separated by reversed-phase HPLC. The method detected an atypical cleavage pattern by one of the formulated drug products. IncobotulinumtoxinA produced two cleavage fragments rather than the single fragment typically generated by BoNT/A. Identification confirmed the secondary cleavage at a position corresponding to SNAP-25 Arg198–Ala199 (normal BoNT/A cleavage is Gln197–Arg198. Arg198–Ala199 is also the cleavage site for trypsin and serotype C toxin. Normal cleavage was observed for all other BoNT/A drug product samples, as well as 900-kD and 150-kD bulk toxin BoNT/A. The reason for this unexpected secondary cleavage pattern by one formulated BoNT/A drug product is unknown. Possible explanations include a contaminating protease and/or damage to the 150-kD type-A toxin causing nonspecific substrate recognition and subsequent cleavage uncharacteristic of type-A toxin. The BoNT/A drug products were also analyzed via the LCA-HPLC assay using a commercial BoNT/C fluorescent substrate derived from the syntaxin sequence. Cleavage of the serotype C substrate by incobotulinumtoxinA was also confirmed whilst neither of the other drug products cleaved the syntaxin substrate.

  14. A study on expression levels of matrix metalloproteinases and their ...

    African Journals Online (AJOL)

    Keywords: Ulcerative colitis, Matrix metalloproteinases, Tissue inhibitors of metalloproteinases, Lamina propria ... The symptoms of UC include diarrhea with blood, fever ..... Eisen A, Jeffrey J, Gross J. Human skin collagenase. Isolation and ...

  15. Sequence specificity of DNA cleavage by Micrococcus luteus γ endonuclease

    International Nuclear Information System (INIS)

    Hentosh, P.; Henner, W.D.; Reynolds, R.J.

    1985-01-01

    DNA fragments of defined sequence have been used to determine the sites of cleavage by γ-endonuclease activity in extracts prepared from Micrococcus luteus. End-labeled DNA restriction fragments of pBR322 DNA that had been irradiated under nitrogen in the presence of potassium iodide or t-butanol were treated with M. luteus γ endonuclease and analyzed on irradiated DNA preferentially at the positions of cytosines and thymines. DNA cleavage occurred immediately to the 3' side of pyrimidines in irradiated DNA and resulted in fragments that terminate in a 5'-phosphoryl group. These studies indicate that both altered cytosines and thymines may be important DNA lesions requiring repair after exposure to γ radiation

  16. Discovery of a highly selective chemical inhibitor of matrix metalloproteinase-9 (MMP-9) that allosterically inhibits zymogen activation.

    Science.gov (United States)

    Scannevin, Robert H; Alexander, Richard; Haarlander, Tara Mezzasalma; Burke, Sharon L; Singer, Monica; Huo, Cuifen; Zhang, Yue-Mei; Maguire, Diane; Spurlino, John; Deckman, Ingrid; Carroll, Karen I; Lewandowski, Frank; Devine, Eric; Dzordzorme, Keli; Tounge, Brett; Milligan, Cindy; Bayoumy, Shariff; Williams, Robyn; Schalk-Hihi, Celine; Leonard, Kristi; Jackson, Paul; Todd, Matthew; Kuo, Lawrence C; Rhodes, Kenneth J

    2017-10-27

    Aberrant activation of matrix metalloproteinases (MMPs) is a common feature of pathological cascades observed in diverse disorders, such as cancer, fibrosis, immune dysregulation, and neurodegenerative diseases. MMP-9, in particular, is highly dynamically regulated in several pathological processes. Development of MMP inhibitors has therefore been an attractive strategy for therapeutic intervention. However, a long history of failed clinical trials has demonstrated that broad-spectrum MMP inhibitors have limited clinical utility, which has spurred the development of inhibitors selective for individual MMPs. Attaining selectivity has been technically challenging because of sequence and structural conservation across the various MMPs. Here, through a biochemical and structural screening paradigm, we have identified JNJ0966, a highly selective compound that inhibited activation of MMP-9 zymogen and subsequent generation of catalytically active enzyme. JNJ0966 had no effect on MMP-1, MMP-2, MMP-3, MMP-9, or MMP-14 catalytic activity and did not inhibit activation of the highly related MMP-2 zymogen. The molecular basis for this activity was characterized as an interaction of JNJ0966 with a structural pocket in proximity to the MMP-9 zymogen cleavage site near Arg-106, which is distinct from the catalytic domain. JNJ0966 was efficacious in reducing disease severity in a mouse experimental autoimmune encephalomyelitis model, demonstrating the viability of this therapeutic approach. This discovery reveals an unprecedented pharmacological approach to MMP inhibition, providing an opportunity to improve selectivity of future clinical drug candidates. Targeting zymogen activation in this manner may also allow for pharmaceutical exploration of other enzymes previously viewed as intractable drug targets. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Structural and Biochemical Characterization of a Copper-Binding Mutant of the Organomercurial Lyase MerB: Insight into the Key Role of the Active Site Aspartic Acid in Hg-Carbon Bond Cleavage and Metal Binding Specificity.

    Science.gov (United States)

    Wahba, Haytham M; Lecoq, Lauriane; Stevenson, Michael; Mansour, Ahmed; Cappadocia, Laurent; Lafrance-Vanasse, Julien; Wilkinson, Kevin J; Sygusch, Jurgen; Wilcox, Dean E; Omichinski, James G

    2016-02-23

    In bacterial resistance to mercury, the organomercurial lyase (MerB) plays a key role in the detoxification pathway through its ability to cleave Hg-carbon bonds. Two cysteines (C96 and C159; Escherichia coli MerB numbering) and an aspartic acid (D99) have been identified as the key catalytic residues, and these three residues are conserved in all but four known MerB variants, where the aspartic acid is replaced with a serine. To understand the role of the active site serine, we characterized the structure and metal binding properties of an E. coli MerB mutant with a serine substituted for D99 (MerB D99S) as well as one of the native MerB variants containing a serine residue in the active site (Bacillus megaterium MerB2). Surprisingly, the MerB D99S protein copurified with a bound metal that was determined to be Cu(II) from UV-vis absorption, inductively coupled plasma mass spectrometry, nuclear magnetic resonance, and electron paramagnetic resonance studies. X-ray structural studies revealed that the Cu(II) is bound to the active site cysteine residues of MerB D99S, but that it is displaced following the addition of either an organomercurial substrate or an ionic mercury product. In contrast, the B. megaterium MerB2 protein does not copurify with copper, but the structure of the B. megaterium MerB2-Hg complex is highly similar to the structure of the MerB D99S-Hg complexes. These results demonstrate that the active site aspartic acid is crucial for both the enzymatic activity and metal binding specificity of MerB proteins and suggest a possible functional relationship between MerB and its only known structural homologue, the copper-binding protein NosL.

  18. On the formation and nature of quasi-cleavage fracture surfaces in hydrogen embrittled steels

    Energy Technology Data Exchange (ETDEWEB)

    Martin, May L.; Fenske, Jamey A.; Liu, Grace S.; Sofronis, Petros [University of Illinois, Dept. of Materials Science and Engineering, 1304 W. Green St., Urbana, IL 61801 (United States); Robertson, Ian M., E-mail: ianr@illinois.edu [University of Illinois, Dept. of Materials Science and Engineering, 1304 W. Green St., Urbana, IL 61801 (United States)

    2011-02-15

    Quasi-cleavage, a common feature of hydrogen-induced fracture surfaces, is generally taken as being cleavage-like but not along a known cleavage plane. Despite the frequency with which this surface is observed, the relationship to the underlying microstructure remains unknown. Through a combination of topographical reconstruction of secondary electron microscope fractographs and a transmission electron microscopy study of the microstructure from site-specific locations, it will be shown that the features on quasi-cleavage surfaces are ridges that can be correlated with sub-surface intense and highly localized deformation bands. It will be demonstrated that the fracture surface arises from the growth and coalescence of voids that initiate at and extend along slip band intersections. This mechanism and process is fully consistent with hydrogen enhancing and localizing plastic processes.

  19. Structure of the cleavage-activated prefusion form of the parainfluenza virus 5 fusion protein.

    Science.gov (United States)

    Welch, Brett D; Liu, Yuanyuan; Kors, Christopher A; Leser, George P; Jardetzky, Theodore S; Lamb, Robert A

    2012-10-09

    The paramyxovirus parainfluenza virus 5 (PIV5) enters cells by fusion of the viral envelope with the plasma membrane through the concerted action of the fusion (F) protein and the receptor binding protein hemagglutinin-neuraminidase. The F protein folds initially to form a trimeric metastable prefusion form that is triggered to undergo large-scale irreversible conformational changes to form the trimeric postfusion conformation. It is thought that F refolding couples the energy released with membrane fusion. The F protein is synthesized as a precursor (F0) that must be cleaved by a host protease to form a biologically active molecule, F1,F2. Cleavage of F protein is a prerequisite for fusion and virus infectivity. Cleavage creates a new N terminus on F1 that contains a hydrophobic region, known as the FP, which intercalates target membranes during F protein refolding. The crystal structure of the soluble ectodomain of the uncleaved form of PIV5 F is known; here we report the crystal structure of the cleavage-activated prefusion form of PIV5 F. The structure shows minimal movement of the residues adjacent to the protease cleavage site. Most of the hydrophobic FP residues are buried in the uncleaved F protein, and only F103 at the newly created N terminus becomes more solvent-accessible after cleavage. The conformational freedom of the charged arginine residues that compose the protease recognition site increases on cleavage of F protein.

  20. Identification of accelerated evolution in the metalloproteinase ...

    African Journals Online (AJOL)

    U

    2016-02-24

    Feb 24, 2016 ... drugs for different diseases. Key words: SVMPs, evolution, multiple sequence alignment, phylogenic tree, secondary structure, homology. ... in matrix metalloproteinase genes MMP1, MMP9 and. MMP12 are shown to be ... Evolution and diversification of snake venom is a very interesting phenomenon.

  1. Programmable RNA recognition and cleavage by CRISPR/Cas9.

    Science.gov (United States)

    O'Connell, Mitchell R; Oakes, Benjamin L; Sternberg, Samuel H; East-Seletsky, Alexandra; Kaplan, Matias; Doudna, Jennifer A

    2014-12-11

    The CRISPR-associated protein Cas9 is an RNA-guided DNA endonuclease that uses RNA-DNA complementarity to identify target sites for sequence-specific double-stranded DNA (dsDNA) cleavage. In its native context, Cas9 acts on DNA substrates exclusively because both binding and catalysis require recognition of a short DNA sequence, known as the protospacer adjacent motif (PAM), next to and on the strand opposite the twenty-nucleotide target site in dsDNA. Cas9 has proven to be a versatile tool for genome engineering and gene regulation in a large range of prokaryotic and eukaryotic cell types, and in whole organisms, but it has been thought to be incapable of targeting RNA. Here we show that Cas9 binds with high affinity to single-stranded RNA (ssRNA) targets matching the Cas9-associated guide RNA sequence when the PAM is presented in trans as a separate DNA oligonucleotide. Furthermore, PAM-presenting oligonucleotides (PAMmers) stimulate site-specific endonucleolytic cleavage of ssRNA targets, similar to PAM-mediated stimulation of Cas9-catalysed DNA cleavage. Using specially designed PAMmers, Cas9 can be specifically directed to bind or cut RNA targets while avoiding corresponding DNA sequences, and we demonstrate that this strategy enables the isolation of a specific endogenous messenger RNA from cells. These results reveal a fundamental connection between PAM binding and substrate selection by Cas9, and highlight the utility of Cas9 for programmable transcript recognition without the need for tags.

  2. Matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in diagnosis of pleural effusion of malignant origin.

    Science.gov (United States)

    Fiorelli, Alfonso; Ricci, Serena; Feola, Antonia; Mazzella, Antonio; D'Angelo, Luigi; Santini, Mario; Di Domenico, Marina; Di Carlo, Angelina

    2016-04-01

    The aim of the present study was to evaluate the diagnostic accuracy of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in differentiating benign from malignant exudative pleural effusions. This is a unicentre observational study including 97 consecutive patients with exudative pleural effusions. Metalloproteinase-9, tissue inhibitor of metalloproteinase-1, lactate dehydrogenase, ferritin, carcinoembryonic antigen and carbohydrate antigen 15-3 were measured in pleural effusion and serum by enzyme-linked immunosorbent assay. The activity of metalloproteinase-9 was also evaluated by substrate zymography. The data were correlated with final diagnosis of pleural effusions to evaluate the diagnostic accuracy. Of the 97 eligible patients, 6 were excluded. Of the 91 patients included in the study, 70 had malignant pleural effusions and 21 had benign pleural effusions. Both in sera and pleural effusions, matrix metalloproteinase-9 (P effusion (P effusion metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 levels showed higher value of sensitivity (97 and 91%, respectively) and specificity (90 and 95%, respectively) compared with other standard markers. Serum metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 levels showed similar results. Among 70 neoplastic patients, 29 had negative pleural cytology. Of these, 25 presented elevated levels of metalloproteinase-9 and tissue inhibitor of metalloproteinase-1, whereas 4 patients had elevated levels of one of the two markers. Our results showed that metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 might be valuable markers in differentiating benign from malignant pleural effusions. Their levels are neither influenced by the histology and tumour origin nor by the presence of tumour cells in pleural effusions. Thus, their use in clinical practice could help in the selection of patients needing more invasive procedures, such as thoracoscopic biopsy. © The Author 2016

  3. Dentin matrix degradation by host Matrix Metalloproteinases: inhibition and clinical perspectives towards regeneration.

    Directory of Open Access Journals (Sweden)

    Catherine eChaussain

    2013-11-01

    Full Text Available Bacterial enzymes have long been considered solely accountable for the degradation of the dentin matrix during the carious process. However, the emerging literature suggests that host-derived enzymes, and in particular the matrix metalloproteinases (MMPs contained in dentin and saliva can play a major role in this process by their ability to degrade the dentin matrix from within. These findings are important since they open new therapeutic options for caries prevention and treatment. The possibility of using MMP inhibitors to interfere with dentin caries progression is discussed. Furthermore, the potential release of bioactive peptides by the enzymatic cleavage of dentin matrix proteins by MMPs during the carious process is discussed. These peptides, once identified, may constitute promising therapeutical tools for tooth and bone regeneration.

  4. The large terminase DNA packaging motor grips DNA with its ATPase domain for cleavage by the flexible nuclease domain

    Science.gov (United States)

    Hilbert, Brendan J.; Hayes, Janelle A.; Stone, Nicholas P.; Xu, Rui-Gang

    2017-01-01

    Abstract Many viruses use a powerful terminase motor to pump their genome inside an empty procapsid shell during virus maturation. The large terminase (TerL) protein contains both enzymatic activities necessary for packaging in such viruses: the adenosine triphosphatase (ATPase) that powers DNA translocation and an endonuclease that cleaves the concatemeric genome at both initiation and completion of genome packaging. However, how TerL binds DNA during translocation and cleavage remains mysterious. Here we investigate DNA binding and cleavage using TerL from the thermophilic phage P74-26. We report the structure of the P74-26 TerL nuclease domain, which allows us to model DNA binding in the nuclease active site. We screened a large panel of TerL variants for defects in binding and DNA cleavage, revealing that the ATPase domain is the primary site for DNA binding, and is required for nuclease activity. The nuclease domain is dispensable for DNA binding but residues lining the active site guide DNA for cleavage. Kinetic analysis of DNA cleavage suggests flexible tethering of the nuclease domains during DNA cleavage. We propose that interactions with the procapsid during DNA translocation conformationally restrict the nuclease domain, inhibiting cleavage; TerL release from the capsid upon completion of packaging unlocks the nuclease domains to cleave DNA. PMID:28082398

  5. EMMPRIN modulates epithelial barrier function through a MMP-mediated occludin cleavage: implications in dry eye disease.

    Science.gov (United States)

    Huet, Eric; Vallée, Benoit; Delbé, Jean; Mourah, Samia; Prulière-Escabasse, Virginie; Tremouilleres, Magali; Kadomatsu, Kenji; Doan, Serge; Baudouin, Christophe; Menashi, Suzanne; Gabison, Eric E

    2011-09-01

    Dry eye is a common disease that develops as a result of alteration of tear fluid, leading to osmotic stress and a perturbed epithelial barrier. Matrix metalloproteinase-9 (MMP-9) may be important in dry eye disease, as its genetic knockout conferred resistance to the epithelial disruption. We show that extracellular matrix metalloproteinase inducer (EMMPRIN; also termed CD147), an inducer of MMP expression, participates in the pathogenesis of dry eye through MMP-mediated cleavage of occludin, an important component of tight junctions. EMMPRIN expression was increased on the ocular surface of dry eye patients and correlated with those of MMP-9. High osmolarity in cell culture, mimicking dry eye conditions, increased both EMMPRIN and MMP-9 and resulted in the disruption of epithelial junctions through the cleavage of occludin. Exogenously added recombinant EMMPRIN had similar effects that were abrogated in the presence of the MMP inhibitor marimastat. Membrane occludin immunostaining was markedly increased in the apical corneal epithelium of both EMMPRIN and MMP-9 knock-out mice. Furthermore, an inverse correlation between EMMPRIN and occludin membrane staining was consistently observed both in vitro and in vivo as a function of corneal epithelial cells differentiation. These data suggest a possible role of EMMPRIN in regulating the amount of occludin at the cell surface in homeostasis beyond pathological situations such as dry eye disease, and EMMPRIN may be essential for the formation and maintenance of organized epithelial structure. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  6. Calicivirus 3C-like proteinase inhibits cellular translation by cleavage of poly(A)-binding protein.

    Science.gov (United States)

    Kuyumcu-Martinez, Muge; Belliot, Gaël; Sosnovtsev, Stanislav V; Chang, Kyeong-Ok; Green, Kim Y; Lloyd, Richard E

    2004-08-01

    Caliciviruses are single-stranded RNA viruses that cause a wide range of diseases in both humans and animals, but little is known about the regulation of cellular translation during infection. We used two distinct calicivirus strains, MD145-12 (genus Norovirus) and feline calicivirus (FCV) (genus Vesivirus), to investigate potential strategies used by the caliciviruses to inhibit cellular translation. Recombinant 3C-like proteinases (r3CL(pro)) from norovirus and FCV were found to cleave poly(A)-binding protein (PABP) in the absence of other viral proteins. The norovirus r3CL(pro) PABP cleavage products were indistinguishable from those generated by poliovirus (PV) 3C(pro) cleavage, while the FCV r3CL(pro) products differed due to cleavage at an alternate cleavage site 24 amino acids downstream of one of the PV 3C(pro) cleavage sites. All cleavages by calicivirus or PV proteases separated the C-terminal domain of PABP that binds translation factors eIF4B and eRF3 from the N-terminal RNA-binding domain of PABP. The effect of PABP cleavage by the norovirus r3CL(pro) was analyzed in HeLa cell translation extracts, and the presence of r3CL(pro) inhibited translation of both endogenous and exogenous mRNAs. Translation inhibition was poly(A) dependent, and replenishment of the extracts with PABP restored translation. Analysis of FCV-infected feline kidney cells showed that the levels of de novo cellular protein synthesis decreased over time as virus-specific proteins accumulated, and cleavage of PABP occurred in virus-infected cells. Our data indicate that the calicivirus 3CL(pro), like PV 3C(pro), mediates the cleavage of PABP as part of its strategy to inhibit cellular translation. PABP cleavage may be a common mechanism among certain virus families to manipulate cellular translation.

  7. Multifaceted role of matrix metalloproteinases (MMPs)

    OpenAIRE

    Singh, Divya; Srivastava, Sanjeev K.; Chaudhuri, Tapas K.; Upadhyay, Ghanshyam

    2015-01-01

    Matrix metalloproteinases (MMPs), a large family of calcium-dependent zinc-containing endopeptidases, are involved in the tissue remodeling and degradation of the extracellular matrix. MMPs are widely distributed in the brain and regulate various processes including microglial activation, inflammation, dopaminergic apoptosis, blood-brain barrier disruption, and modulation of ?-synuclein pathology. High expression of MMPs is well documented in various neurological disorders including Parkinson...

  8. Detection of Matrix Metalloproteinases by Zymography.

    Science.gov (United States)

    Tajhya, Rajeev B; Patel, Rutvik S; Beeton, Christine

    2017-01-01

    Matrix metalloproteinases (MMPs) represent more than 20 zinc-containing endopeptidases that cleave internal peptide bonds, leading to protein degradation. They play a critical role in many physiological cell functions, including tissue remodeling, embryogenesis, and angiogenesis. They are also involved in the pathogenesis of a vast array of diseases, including but not limited to systemic inflammation, various cancers, and cardiovascular, neurological, and autoimmune diseases. Here, we describe gel zymography to detect MMPs in cell and tissue samples and in cell culture supernatants.

  9. Matrix metalloproteinases in exercise and obesity

    OpenAIRE

    Jaoude, Jonathan; Koh, Yunsuk

    2016-01-01

    Jonathan Jaoude,1 Yunsuk Koh2 1Department of Biology, 2Department of Health, Human Performance, and Recreation, Baylor University, Waco, TX, USA Abstract: Matrix metalloproteinases (MMPs) are zinc- and calcium-dependent endoproteinases that have the ability to break down extracellular matrix. The large range of MMPs’ functions widens their spectrum of potential role as activators or inhibitors in tissue remodeling, cardiovascular diseases, and obesity. In particular, MMP-1, -2, and ...

  10. Caspase activation increases beta-amyloid generation independently of caspase cleavage of the beta-amyloid precursor protein (APP).

    Science.gov (United States)

    Tesco, Giuseppina; Koh, Young Ho; Tanzi, Rudolph E

    2003-11-14

    The amyloid precursor protein (APP) undergoes "alternative" proteolysis mediated by caspases. Three major caspase recognition sites have been identified in the APP, i.e. one at the C terminus (Asp720) and two at the N terminus (Asp197 and Asp219). Caspase cleavage at Asp720 has been suggested as leading to increased production of Abeta. Thus, we set out to determine which putative caspase sites in APP, if any, are cleaved in Chinese hamster ovary cell lines concurrently with the increased Abeta production that occurs during apoptosis. We found that cleavage at Asp720 occurred concurrently with caspase 3 activation and the increased production of total secreted Abeta and Abeta1-42 in association with staurosporine- and etoposide-induced apoptosis. To investigate the contribution of caspase cleavage of APP to Abeta generation, we expressed an APP mutant truncated at Asp720 that mimics APP caspase cleavage at the C-terminal site. This did not increase Abeta generation but, in contrast, dramatically decreased Abeta production in Chinese hamster ovary cells. Furthermore, the ablation of caspase-dependent cleavage at Asp720, Asp197, and Asp219 (by site-directed mutagenesis) did not prevent enhanced Abeta production following etoposide-induced apoptosis. These findings indicate that the enhanced Abeta generation associated with apoptosis does not require cleavage of APP at its C-terminal (Asp720) and/or N-terminal caspase sites.

  11. Cleavage specificity analysis of six type II transmembrane serine proteases (TTSPs using PICS with proteome-derived peptide libraries.

    Directory of Open Access Journals (Sweden)

    Olivier Barré

    Full Text Available Type II transmembrane serine proteases (TTSPs are a family of cell membrane tethered serine proteases with unclear roles as their cleavage site specificities and substrate degradomes have not been fully elucidated. Indeed just 52 cleavage sites are annotated in MEROPS, the database of proteases, their substrates and inhibitors.To profile the active site specificities of the TTSPs, we applied Proteomic Identification of protease Cleavage Sites (PICS. Human proteome-derived database searchable peptide libraries were assayed with six human TTSPs (matriptase, matriptase-2, matriptase-3, HAT, DESC and hepsin to simultaneously determine sequence preferences on the N-terminal non-prime (P and C-terminal prime (P' sides of the scissile bond. Prime-side cleavage products were isolated following biotinylation and identified by tandem mass spectrometry. The corresponding non-prime side sequences were derived from human proteome databases using bioinformatics. Sequencing of 2,405 individual cleaved peptides allowed for the development of the family consensus protease cleavage site specificity revealing a strong specificity for arginine in the P1 position and surprisingly a lysine in P1' position. TTSP cleavage between R↓K was confirmed using synthetic peptides. By parsing through known substrates and known structures of TTSP catalytic domains, and by modeling the remainder, structural explanations for this strong specificity were derived.Degradomics analysis of 2,405 cleavage sites revealed a similar and characteristic TTSP family specificity at the P1 and P1' positions for arginine and lysine in unfolded peptides. The prime side is important for cleavage specificity, thus making these proteases unusual within the tryptic-enzyme class that generally has overriding non-prime side specificity.

  12. Yeast ribonuclease III uses a network of multiple hydrogen bonds for RNA binding and cleavage.

    Science.gov (United States)

    Lavoie, Mathieu; Abou Elela, Sherif

    2008-08-19

    Members of the bacterial RNase III family recognize a variety of short structured RNAs with few common features. It is not clear how this group of enzymes supports high cleavage fidelity while maintaining a broad base of substrates. Here we show that the yeast orthologue of RNase III (Rnt1p) uses a network of 2'-OH-dependent interactions to recognize substrates with different structures. We designed a series of bipartite substrates permitting the distinction between binding and cleavage defects. Each substrate was engineered to carry a single or multiple 2'- O-methyl or 2'-fluoro ribonucleotide substitutions to prevent the formation of hydrogen bonds with a specific nucleotide or group of nucleotides. Interestingly, introduction of 2'- O-methyl ribonucleotides near the cleavage site increased the rate of catalysis, indicating that 2'-OH are not required for cleavage. Substitution of nucleotides in known Rnt1p binding site with 2'- O-methyl ribonucleotides inhibited cleavage while single 2'-fluoro ribonucleotide substitutions did not. This indicates that while no single 2'-OH is essential for Rnt1p cleavage, small changes in the substrate structure are not tolerated. Strikingly, several nucleotide substitutions greatly increased the substrate dissociation constant with little or no effect on the Michaelis-Menten constant or rate of catalysis. Together, the results indicate that Rnt1p uses a network of nucleotide interactions to identify its substrate and support two distinct modes of binding. One mode is primarily mediated by the dsRNA binding domain and leads to the formation of stable RNA/protein complex, while the other requires the presence of the nuclease and N-terminal domains and leads to RNA cleavage.

  13. Monoclonal antibodies to the reactive centre loop (RCL) of human corticosteroid-binding globulin (CBG) can protect against proteolytic cleavage.

    Science.gov (United States)

    Lewis, John G; Elder, Peter A

    2017-07-01

    Corticosteroid-binding globulin (CBG) binds most of the cortisol in circulation and is a non-functional member of the family of serine protease inhibitors (serpins) with an exposed elastase sensitive reactive centre loop (RCL). The RCL can be cleaved by human neutrophil elastase, released from activated neutrophils, and can also be cleaved at nearby site(s) by elastase released by Pseudomonas aeruginosa, and at two further sites, also within the RCL, by bovine chymotrypsin. Cleavage of the RCL results in a conformational change accompanied by a marked decrease in affinity for cortisol and hence its release at the site of proteolysis. These cleavages are irreversible and the similar half-lives of cleaved and intact CBG could mean that there may be some advantage in slowing the rate of CBG cleavage in acute inflammation thereby increasing the proportion of intact CBG in circulation. Here we show, for the first time, that pre-incubation of tethered human CBG with two monoclonal antibodies to the RCL of CBG protects against cleavage by all three enzymes. Furthermore, in plasma, pre-incubation with both RCL monoclonal antibodies delays neutrophil elastase cleavage of the RCL and one of these RCL monoclonal antibodies also delays bovine chymotrypsin cleavage of the RCL. These findings may provide a basis and rationale for the concept of the use of RCL antibodies as therapeutic agents to effectively increase the proportion of intact CBG in circulation which may be of benefit in acute inflammation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Predicting proteasomal cleavage sites: a comparison of available methods

    DEFF Research Database (Denmark)

    Saxova, P.; Buus, S.; Brunak, Søren

    2003-01-01

    -terminal, in particular, of CTL epitopes is cleaved precisely by the proteasome, whereas the N-terminal is produced with an extension, and later trimmed by peptidases in the cytoplasm and in the endoplasmic reticulum. Recently, three publicly available methods have been developed for prediction of the specificity...

  15. Chemically modified tetracyclines stimulate matrix metalloproteinase-s production by periodontal ligament cells

    NARCIS (Netherlands)

    Bildt, M.M.; Snoek-van Beurden, A.M.P.; Groot, J. de; El, B. van; Kuijpers-Jagtman, A.M.; Hoff, J.W. van den

    2006-01-01

    Background and Objective: The purpose of this study was to investigate the effects of chemically modified tetracyclines (CMTs) on the production of gelatinases [matrix metalloproteinase (MMP)-2 and -9] by human periodontal ligament (PDL) cells, and on the activity of recombinant gelatinases.

  16. [Cleavage of DNA fragments induced by UV nanosecond laser excitation at 193 nm].

    Science.gov (United States)

    Vtiurina, N N; Grokhovskiĭ, S L; Filimonov, I V; Medvedkov, O I; Nechipurenko, D Iu; Vasil'ev, S A; Nechipurenko, Iu D

    2011-01-01

    The cleavage of dsDNA fragments in aqueous solution after irradiation with UV laser pulses at 193 nm has been studied. Samples were investigated using polyacrylamide gel electrophoresis. The intensity of damage of particular phosphodiester bond after hot alkali treatment was shown to depend on the base pair sequence. It was established that the probability of cleavage is twice higher for sites of DNA containing two or more successively running guanine residues. A possible mechanism of damage to the DNA molecule connected with the migration of holes along the helix is discussed.

  17. Assessment of Matrix Metalloproteinases by Gelatin Zymography.

    Science.gov (United States)

    Cathcart, Jillian

    2016-01-01

    Matrix metalloproteinases are endopeptidases responsible for remodeling of the extracellular matrix and have been identified as critical contributors to breast cancer progression. Gelatin zymography is a valuable tool which allows the analysis of MMP expression. In this approach, enzymes are resolved electrophoretically on a sodium dodecyl sulfate-polyacrylamide gel copolymerized with the substrate for the MMP of interest. Post electrophoresis, the enzymes are refolded in order for proteolysis of the incorporated substrate to occur. This assay yields valuable information about MMP isoforms or changes in activation and can be used to analyze the role of MMPs in normal versus pathological conditions.

  18. Matrix metalloproteinase-12 (MMP-12) in osteoclasts

    DEFF Research Database (Denmark)

    Hou, Peng; Troen, Tine; Ovejero, Maria C

    2004-01-01

    Osteoclasts require matrix metalloproteinase (MMP) activity and cathepsin K to resorb bone, but the critical MMP has not been identified. Osteoclasts express MMP-9 and MMP-14, which do not appear limiting for resorption, and the expression of additional MMPs is not clear. MMP-12, also called...... bone show MMP-12 expression in osteoclasts in calvariae and long bones. We also demonstrate that recombinant MMP-12 cleaves the putative functional domains of osteopontin and bone sialoprotein, two bone matrix proteins that strongly influence osteoclast activities, such as attachment, spreading...

  19. Stimulation of topoisomerase II mediated DNA cleavage at specific sequence elements by the 2-nitroimidazole Ro 15-0216

    International Nuclear Information System (INIS)

    Sorensen, B.S.; Jensen, P.S.; Andersen, A.H.; Christiansen, K.; Alsner, J.; Thomsen, B.; Westergaard, O.

    1990-01-01

    The effect of the 2-nitroimidazole Ro 15-0216 upon the interaction between purified topoisomerase II and its DNA substrate was investigated. The cleavage reaction in the presence of this DNA-nonintercalative drug took place with the hallmarks of a regular topoisomerase II mediated cleavage reaction, including covalent linkage of the enzyme to the cleaved DNA. In the presence of Ro 15-0216, topoisomerase II mediated cleavage was extensively stimulated at major cleavage sites of which only one existed in the 4363 base pair pBR322 molecule. The sites stimulated by Ro 15-0216 shared a pronounced sequence homology, indicating that a specific nucleotide sequence is crucial for the action of this drug. The effect of Ro 15-0216 thus differs from that of the clinically important topoisomerase II targeted agents such as mAMSA, VM26, and VP16, which enhance enzyme-mediated cleavage at a multiple number of sites. In contrast to the previous described drugs, Ro 15-0216 did not exert any inhibitory effect on the enzyme's catalytic activity. This observation might be ascribed to the low stability of the cleavage complexes formed in the presence of Ro 15-0216 as compared to the stability of the ones formed in the presence of traditional topoisomerase II targeted drugs

  20. Mutation G805R in the transmembrane domain of the LDL receptor gene causes familial hypercholesterolemia by inducing ectodomain cleavage of the LDL receptor in the endoplasmic reticulum

    Directory of Open Access Journals (Sweden)

    Thea Bismo Strøm

    2014-01-01

    Full Text Available More than 1700 mutations in the low density lipoprotein receptor (LDLR gene have been found to cause familial hypercholesterolemia (FH. These are commonly divided into five classes based upon their effects on the structure and function of the LDLR. However, little is known about the mechanism by which mutations in the transmembrane domain of the LDLR gene cause FH. We have studied how the transmembrane mutation G805R affects the function of the LDLR. Based upon Western blot analyses of transfected HepG2 cells, mutation G805R reduced the amounts of the 120 kDa precursor LDLR in the endoplasmic reticulum. This led to reduced amounts of the mature 160 kDa LDLR at the cell surface. However, significant amounts of a secreted 140 kDa G805R-LDLR ectodomain fragment was observed in the culture media. Treatment of the cells with the metalloproteinase inhibitor batimastat largely restored the amounts of the 120 and 160 kDa forms in cell lysates, and prevented secretion of the 140 kDa ectodomain fragment. Together, these data indicate that a metalloproteinase cleaved the ectodomain of the 120 kDa precursor G805R-LDLR in the endoplasmic reticulum. It was the presence of the polar Arg805 and not the lack of Gly805 which led to ectodomain cleavage. Arg805 also prevented γ-secretase cleavage within the transmembrane domain. It is conceivable that introducing a charged residue within the hydrophobic membrane lipid bilayer, results in less efficient incorporation of the 120 kDa G805R-LDLR in the endoplasmic reticulum membrane and makes it a substrate for metalloproteinase cleavage.

  1. A study on the expression levels of matrix metalloproteinases and ...

    African Journals Online (AJOL)

    Conclusion: MMP-2, MMP-7, and MMP-9 are potential targets for therapeutic control of UC. Keywords: Glandular epithelium, Inflammatory cells, Inhibitors, Matrix metalloproteinases (MMPs),. Tissue inhibitors of metalloproteinases, Ulcerative colitis. Tropical Journal of Pharmaceutical Research is indexed by Science ...

  2. Urinary metalloproteinases: noninvasive biomarkers for breast cancer risk assessment

    DEFF Research Database (Denmark)

    Pories, Susan E; Zurakowski, David; Roy, Roopali

    2008-01-01

    Matrix metalloproteinases (MMP) and a disintegrin and metalloprotease 12 (ADAM 12) can be detected in the urine of breast cancer patients and provide independent prediction of disease status. To evaluate the potential of urinary metalloproteinases as biomarkers to predict breast cancer risk statu...

  3. Controllable laser thermal cleavage of sapphire wafers

    Science.gov (United States)

    Xu, Jiayu; Hu, Hong; Zhuang, Changhui; Ma, Guodong; Han, Junlong; Lei, Yulin

    2018-03-01

    Laser processing of substrates for light-emitting diodes (LEDs) offers advantages over other processing techniques and is therefore an active research area in both industrial and academic sectors. The processing of sapphire wafers is problematic because sapphire is a hard and brittle material. Semiconductor laser scribing processing suffers certain disadvantages that have yet to be overcome, thereby necessitating further investigation. In this work, a platform for controllable laser thermal cleavage was constructed. A sapphire LED wafer was modeled using the finite element method to simulate the thermal and stress distributions under different conditions. A guide groove cut by laser ablation before the cleavage process was observed to guide the crack extension and avoid deviation. The surface and cross section of sapphire wafers processed using controllable laser thermal cleavage were characterized by scanning electron microscopy and optical microscopy, and their morphology was compared to that of wafers processed using stealth dicing. The differences in luminous efficiency between substrates prepared using these two processing methods are explained.

  4. Pressure modulates the self-cleavage step of the hairpin ribozyme

    Science.gov (United States)

    Schuabb, Caroline; Kumar, Narendra; Pataraia, Salome; Marx, Dominik; Winter, Roland

    2017-03-01

    The ability of certain RNAs, denoted as ribozymes, to not only store genetic information but also catalyse chemical reactions gave support to the RNA world hypothesis as a putative step in the development of early life on Earth. This, however, might have evolved under extreme environmental conditions, including the deep sea with pressures in the kbar regime. Here we study pressure-induced effects on the self-cleavage of hairpin ribozyme by following structural changes in real-time. Our results suggest that compression of the ribozyme leads to an accelerated transesterification reaction, being the self-cleavage step, although the overall process is retarded in the high-pressure regime. The results reveal that favourable interactions between the reaction site and neighbouring nucleobases are strengthened under pressure, resulting therefore in an accelerated self-cleavage step upon compression. These results suggest that properly engineered ribozymes may also act as piezophilic biocatalysts in addition to their hitherto known properties.

  5. Fetal hemoglobin is much less prone to DNA cleavage compared to the adult protein

    Directory of Open Access Journals (Sweden)

    Sandeep Chakane

    2017-08-01

    Full Text Available Hemoglobin (Hb is well protected inside the red blood cells (RBCs. Upon hemolysis and when free in circulation, Hb can be involved in a range of radical generating reactions and may thereby attack several different biomolecules. In this study, we have examined the potential damaging effects of cell-free Hb on plasmid DNA (pDNA. Hb induced cleavage of supercoiled pDNA (sc pDNA which was proportional to the concentration of Hb applied. Almost 70% of sc pDNA was converted to open circular or linear DNA using 10 µM of Hb in 12 h. Hb can be present in several different forms. The oxy (HbO2 and met forms are most reactive, while the carboxy-protein shows only low hydrolytic activity. Hemoglobin A (HbA could easily induce complete pDNA cleavage while fetal hemoglobin (HbF was three-fold less reactive. By inserting, a redox active cysteine residue on the surface of the alpha chain of HbF by site-directed mutagenesis, the DNA cleavage reaction was enhanced by 82%. Reactive oxygen species were not directly involved in the reaction since addition of superoxide dismutase and catalase did not prevent pDNA cleavage. The reactivity of Hb with pDNA can rather be associated with the formation of protein based radicals. Keywords: Adult hemoglobin, Fetal hemoglobin, Supercoiled plasmid DNA, DNA cleavage, Cysteine, Protein radicals

  6. Serum matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 levels in patients with tick-borne encephalitis

    Czech Academy of Sciences Publication Activity Database

    Palus, Martin; Žampachová, E.; Elsterová, Jana; Růžek, Daniel

    2014-01-01

    Roč. 68, č. 2 (2014), s. 165-169 ISSN 0163-4453 R&D Projects: GA ČR GAP502/11/2116 Institutional support: RVO:60077344 Keywords : tick-borne encephalitis * matrix metalloproteinase-9 * tissue inhibitor of metalloproteinase-1 * bloodebrain barrier Subject RIV: EC - Immunology Impact factor: 4.441, year: 2014

  7. Tumorigenic Potential of Extracellular Matrix Metalloproteinase Inducer

    Science.gov (United States)

    Zucker, Stanley; Hymowitz, Michelle; Rollo, Ellen E.; Mann, Richard; Conner, Cathleen E.; Cao, Jian; Foda, Hussein D.; Tompkins, David C.; Toole, Bryan P.

    2001-01-01

    Extracellular matrix metalloproteinase inducer (EMMPRIN), a glycoprotein present on the cancer cell plasma membrane, enhances fibroblast synthesis of matrix metalloproteinases (MMPs). The demonstration that peritumoral fibroblasts synthesize most of the MMPs in human tumors rather than the cancer cells themselves has ignited interest in the role of EMMPRIN in tumor dissemination. In this report we have demonstrated a role for EMMPRIN in cancer progression. Human MDA-MB-436 breast cancer cells, which are tumorigenic but slow growing in vivo, were transfected with EMMPRIN cDNA and injected orthotopically into mammary tissue of female NCr nu/nu mice. Green fluorescent protein was used to visualize metastases. In three experiments, breast cancer cell clones transfected with EMMPRIN cDNA were considerably more tumorigenic and invasive than plasmid-transfected cancer cells. Increased gelatinase A and gelatinase B expression (demonstrated by in situ hybridization and gelatin substrate zymography) was demonstrated in EMMPRIN-enhanced tumors. In contrast to de novo breast cancers in humans, human tumors transplanted into mice elicited minimal stromal or inflammatory cell reactions. Based on these experimental studies and our previous demonstration that EMMPRIN is prominently displayed in human cancer tissue, we propose that EMMPRIN plays an important role in cancer progression by increasing synthesis of MMPs. PMID:11395366

  8. Mast cell-restricted, tetramer-forming tryptases induce aggrecanolysis in articular cartilage by activating matrix metalloproteinase-3 and -13 zymogens.

    Science.gov (United States)

    Magarinos, Natalia J; Bryant, Katherine J; Fosang, Amanda J; Adachi, Roberto; Stevens, Richard L; McNeil, H Patrick

    2013-08-01

    Mouse mast cell protease (mMCP)-6-null C57BL/6 mice lost less aggrecan proteoglycan from the extracellular matrix of their articular cartilage during inflammatory arthritis than wild-type (WT) C57BL/6 mice, suggesting that this mast cell (MC)-specific mouse tryptase plays prominent roles in articular cartilage catabolism. We used ex vivo mouse femoral head explants to determine how mMCP-6 and its human ortholog hTryptase-β mediate aggrecanolysis. Exposure of the explants to recombinant hTryptase-β, recombinant mMCP-6, or lysates harvested from WT mouse peritoneal MCs (PMCs) significantly increased the levels of enzymatically active matrix metalloproteinases (MMP) in cartilage and significantly induced aggrecan loss into the conditioned media, relative to replicate explants exposed to medium alone or lysates collected from mMCP-6-null PMCs. Treatment of cartilage explants with tetramer-forming tryptases generated aggrecan fragments that contained C-terminal DIPEN and N-terminal FFGVG neoepitopes, consistent with MMP-dependent aggrecanolysis. In support of these data, hTryptase-β was unable to induce aggrecan release from the femoral head explants obtained from Chloe mice that resist MMP cleavage at the DIPEN↓FFGVG site in the interglobular domain of aggrecan. In addition, the abilities of mMCP-6-containing lysates from WT PMCs to induce aggrecanolysis were prevented by inhibitors of MMP-3 and MMP-13. Finally, recombinant hTryptase-β was able to activate latent pro-MMP-3 and pro-MMP-13 in vitro. The accumulated data suggest that human and mouse tetramer-forming tryptases are MMP convertases that mediate cartilage damage and the proteolytic loss of aggrecan proteoglycans in arthritis, in part, by activating the zymogen forms of MMP-3 and MMP-13, which are constitutively present in articular cartilage.

  9. Fusobacterium nucleatum binding to complement regulatory protein CD46 modulates the expression and secretion of cytokines and matrix metalloproteinases by oral epithelial cells.

    Science.gov (United States)

    Mahtout, Hayette; Chandad, Fatiha; Rojo, Jose M; Grenier, Daniel

    2011-02-01

    Periodontitis is a chronic inflammatory disease that results in the destruction of the supporting tissues of the teeth. Gingival epithelial cells are an important mechanical barrier and participate in the host inflammatory response to periodontopathogens. The aim of the present study is to investigate the capacity of Fusobacterium nucleatum to bind to the complement regulatory protein CD46 expressed by oral epithelial cells and to determine the impact of the binding on the gene expression and protein secretion of interleukin (IL)-6, IL-8, and matrix metalloproteinase (MMP)-9 by oral epithelial cells. Binding of recombinant human CD46 to the surface of F. nucleatum was demonstrated by immunologic assays. After stimulation of oral epithelial cells with F. nucleatum, gene expression was determined by real-time polymerase chain reaction analysis while protein secretion was monitored by enzyme-linked immunosorbent assays. Heat and protease treatments of bacterial cells reduced CD46 binding. F. nucleatum-bound CD46 mediated the cleavage of C3b in the presence of factor I. Stimulating oral epithelial cells with F. nucleatum at a multiplicity of infection of 50 resulted in a significant upregulation of the gene expression and protein secretion of IL-6, IL-8, and MMP-9 by oral epithelial cells. However, pretreating the epithelial cells with an anti-CD46 polyclonal antibody attenuated the production of IL-6, IL-8, and MMP-9 in response to F. nucleatum. Such an inhibitory effect was not observed with non-specific antibodies. The present study demonstrates that F. nucleatum can bind the complement regulatory protein CD46. The interaction of F. nucleatum with epithelial cell surface CD46 may contribute to increasing the levels of proinflammatory mediators and MMPs in periodontal sites and consequently modulate tissue destruction.

  10. Computational analysis and modeling of cleavage by the immunoproteasome and the constitutive proteasome

    Directory of Open Access Journals (Sweden)

    Lafuente Esther M

    2010-09-01

    Full Text Available Abstract Background Proteasomes play a central role in the major histocompatibility class I (MHCI antigen processing pathway. They conduct the proteolytic degradation of proteins in the cytosol, generating the C-terminus of CD8 T cell epitopes and MHCI-peptide ligands (P1 residue of cleavage site. There are two types of proteasomes, the constitutive form, expressed in most cell types, and the immunoproteasome, which is constitutively expressed in mature dendritic cells. Protective CD8 T cell epitopes are likely generated by the immunoproteasome and the constitutive proteasome, and here we have modeled and analyzed the cleavage by these two proteases. Results We have modeled the immunoproteasome and proteasome cleavage sites upon two non-overlapping sets of peptides consisting of 553 CD8 T cell epitopes, naturally processed and restricted by human MHCI molecules, and 382 peptides eluted from human MHCI molecules, respectively, using N-grams. Cleavage models were generated considering different epitope and MHCI-eluted fragment lengths and the same number of C-terminal flanking residues. Models were evaluated in 5-fold cross-validation. Judging by the Mathew's Correlation Coefficient (MCC, optimal cleavage models for the proteasome (MCC = 0.43 ± 0.07 and the immunoproteasome (MCC = 0.36 ± 0.06 were obtained from 12-residue peptide fragments. Using an independent dataset consisting of 137 HIV1-specific CD8 T cell epitopes, the immunoproteasome and proteasome cleavage models achieved MCC values of 0.30 and 0.18, respectively, comparatively better than those achieved by related methods. Using ROC analyses, we have also shown that, combined with MHCI-peptide binding predictions, cleavage predictions by the immunoproteasome and proteasome models significantly increase the discovery rate of CD8 T cell epitopes restricted by different MHCI molecules, including A*0201, A*0301, A*2402, B*0702, B*2705. Conclusions We have developed models that are specific

  11. Levels of matrix metalloproteinase-1 and tissue inhibitors of metalloproteinase-1 in gastric cancer

    Science.gov (United States)

    Kemik, Ozgur; Kemik, Ahu Sarbay; Sümer, Aziz; Dulger, Ahmet Cumhur; Adas, Mine; Begenik, Huseyin; Hasirci, Ismail; Yilmaz, Ozkan; Purisa, Sevim; Kisli, Erol; Tuzun, Sefa; Kotan, Cetin

    2011-01-01

    AIM: To evaluate the levels of preoperative serum matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in gastric cancer. METHODS: One hundred gastric cancer patients who underwent gastrectomy were enrolled in this study. The serum concentrations of MMP-1 and TIMP-1 in these patients and in fifty healthy controls were determined using an enzyme-linked immunosorbent assay. RESULTS: Higher serum MMP-1 and TIMP-1 levels were observed in patients than in controls (P < 0.001). Serum MMP-1 and TIMP-1 levels were positively associated with morphological appearance, tumor size, depth of wall invasion, lymph node metastasis, liver metastasis, perineural invasion, and pathological stage. They were not significantly associated with age, gender, tumor location, or histological type. CONCLUSION: Increased MMP-1 and TIMP-1 were associated with gastric cancer. Although these markers are not good markers for diagnosis, these markers show in advanced gastric cancer. PMID:21547130

  12. Can laccases catalyze bond cleavage in lignin?

    DEFF Research Database (Denmark)

    Munk, Line; Sitarz, Anna Katarzyna; Kalyani, Dayanand

    2015-01-01

    illustrations of the putative laccase catalyzed reactions, including the possible reactions of the reactive radical intermediates taking place after the initial oxidation of the phenol-hydroxyl groups, we show that i) Laccase activity is able to catalyze bond cleavage in low molecular weight phenolic lignin......-substituted phenols, benzenethiols, polyphenols, and polyamines, which may be oxidized. In addition, the currently available analytical methods that can be used to detect enzyme catalyzed changes in lignin are summarized, and an improved nomenclature for unequivocal interpretation of the action of laccases on lignin...

  13. Abyssal fiction: common shares, colonial cleavages

    Directory of Open Access Journals (Sweden)

    Alexandre Montaury

    2016-12-01

    Full Text Available The paper aims to develop a reflection on the interaction between the legacies of colonialism and traditional symbolic and cultural practices in African Portuguese-speaking spaces. From a preliminary analysis of fictional texts of wide circulation in Brazil, aims to examine the cleavages, or “abyssal lines” that constitute experiences printed in the daily life of the former Portuguese colony of Cape Verde, Mozambique and Angola.---DOI: http://dx.doi.org/10.21881/abriluff.2016n17a378

  14. Transcriptional down-regulation and rRNA cleavage in Dictyostelium discoideum mitochondria during Legionella pneumophila infection.

    Directory of Open Access Journals (Sweden)

    Chenyu Zhang

    2009-05-01

    Full Text Available Bacterial pathogens employ a variety of survival strategies when they invade eukaryotic cells. The amoeba Dictyostelium discoideum is used as a model host to study the pathogenic mechanisms that Legionella pneumophila, the causative agent of Legionnaire's disease, uses to kill eukaryotic cells. Here we show that the infection of D. discoideum by L. pneumophila results in a decrease in mitochondrial messenger RNAs, beginning more than 8 hours prior to detectable host cell death. These changes can be mimicked by hydrogen peroxide treatment, but not by other cytotoxic agents. The mitochondrial large subunit ribosomal RNA (LSU rRNA is also cleaved at three specific sites during the course of infection. Two LSU rRNA fragments appear first, followed by smaller fragments produced by additional cleavage events. The initial LSU rRNA cleavage site is predicted to be on the surface of the large subunit of the mitochondrial ribosome, while two secondary sites map to the predicted interface with the small subunit. No LSU rRNA cleavage was observed after exposure of D. discoideum to hydrogen peroxide, or other cytotoxic chemicals that kill cells in a variety of ways. Functional L. pneumophila type II and type IV secretion systems are required for the cleavage, establishing a correlation between the pathogenesis of L. pneumophila and D. discoideum LSU rRNA destruction. LSU rRNA cleavage was not observed in L. pneumophila infections of Acanthamoeba castellanii or human U937 cells, suggesting that L. pneumophila uses distinct mechanisms to interrupt metabolism in different hosts. Thus, L. pneumophila infection of D. discoideum results in dramatic decrease of mitochondrial RNAs, and in the specific cleavage of mitochondrial rRNA. The predicted location of the cleavage sites on the mitochondrial ribosome suggests that rRNA destruction is initiated by a specific sequence of events. These findings suggest that L. pneumophila specifically disrupts mitochondrial

  15. Binding of matrix metalloproteinase inhibitors to extracellular matrix: 3D-QSAR analysis.

    Science.gov (United States)

    Zhang, Yufen; Lukacova, Viera; Bartus, Vladimir; Nie, Xiaoping; Sun, Guorong; Manivannan, Ethirajan; Ghorpade, Sandeep R; Jin, Xiaomin; Manyem, Shankar; Sibi, Mukund P; Cook, Gregory R; Balaz, Stefan

    2008-10-01

    Binding to the extracellular matrix, one of the most abundant human protein complexes, significantly affects drug disposition. Specifically, the interactions with extracellular matrix determine the free concentrations of small molecules acting in tissues, including signaling peptides, inhibitors of tissue remodeling enzymes such as matrix metalloproteinases, and other drug candidates. The nature of extracellular matrix binding was elucidated for 63 matrix metalloproteinase inhibitors, for which the association constants to an extracellular matrix mimic were reported here. The data did not correlate with lipophilicity as a common determinant of structure-nonspecific, orientation-averaged binding. A hypothetical structure of the binding site of the solidified extracellular matrix surrogate was analyzed using the Comparative Molecular Field Analysis, which needed to be applied in our multi-mode variant. This fact indicates that the compounds bind to extracellular matrix in multiple modes, which cannot be considered as completely orientation-averaged and exhibit structural dependence. The novel comparative molecular field analysis models, exhibiting satisfactory descriptive and predictive abilities, are suitable for prediction of the extracellular matrix binding for the untested chemicals, which are within applicability domains. The results contribute to a better prediction of the pharmacokinetic parameters such as the distribution volume and the tissue-blood partition coefficients, in addition to a more imminent benefit for the development of more effective matrix metalloproteinase inhibitors.

  16. Neutrophil Protease Cleavage of Von Willebrand Factor in Glomeruli – An Anti-thrombotic Mechanism in the Kidney

    Directory of Open Access Journals (Sweden)

    Ramesh Tati

    2017-02-01

    Full Text Available Adequate cleavage of von Willebrand factor (VWF prevents formation of thrombi. ADAMTS13 is the main VWF-cleaving protease and its deficiency results in development of thrombotic microangiopathy. Besides ADAMTS13 other proteases may also possess VWF-cleaving activity, but their physiological importance in preventing thrombus formation is unknown. This study investigated if, and which, proteases could cleave VWF in the glomerulus. The content of the glomerular basement membrane (GBM was studied as a reflection of processes occurring in the subendothelial glomerular space. VWF was incubated with human GBMs and VWF cleavage was assessed by multimer structure analysis, immunoblotting and mass spectrometry. VWF was cleaved into the smallest multimers by the GBM, which contained ADAMTS13 as well as neutrophil proteases, elastase, proteinase 3 (PR3, cathepsin-G and matrix-metalloproteinase 9. The most potent components of the GBM capable of VWF cleavage were in the serine protease or metalloprotease category, but not ADAMTS13. Neutralization of neutrophil serine proteases inhibited GBM-mediated VWF-cleaving activity, demonstrating a marked contribution of elastase and/or PR3. VWF-platelet strings formed on the surface of primary glomerular endothelial cells, in a perfusion system, were cleaved by both elastase and the GBM, a process blocked by elastase inhibitor. Ultramorphological studies of the human kidney demonstrated neutrophils releasing elastase into the GBM. Neutrophil proteases may contribute to VWF cleavage within the subendothelium, adjacent to the GBM, and thus regulate thrombus size. This anti-thrombotic mechanism would protect the normal kidney during inflammation and could also explain why most patients with ADAMTS13 deficiency do not develop severe kidney failure.

  17. Matrix Metalloproteinases in Normal Pregnancy and Preeclampsia

    Science.gov (United States)

    Chen, Juanjuan; Khalil, Raouf A.

    2017-01-01

    Normal pregnancy is associated with marked hemodynamic and uterine changes that allow adequate uteroplacental blood flow and uterine expansion for the growing fetus. These pregnancy-associated changes involve significant uteroplacental and vascular remodeling. Matrix metalloproteinases (MMPs) are important regulators of vascular and uterine remodeling. Increases in MMP-2 and MMP-9 have been implicated in vasodilation, placentation and uterine expansion during normal pregnancy. The increases in MMPs could be induced by the increased production of estrogen and progesterone during pregnancy. MMP expression/activity may be altered during complications of pregnancy. Decreased vascular MMP-2 and MMP-9 may lead to decreased vasodilation, increased vasoconstriction, hypertensive pregnancy and preeclampsia. Abnormal expression of uteroplacental integrins, cytokines and MMPs may lead to decreased maternal tolerance, apoptosis of invasive trophoblast cells, inadequate remodeling of spiral arteries, and reduced uterine perfusion pressure (RUPP). RUPP may cause imbalance between the anti-angiogenic factors soluble fms-like tyrosine kinase-1 and soluble endoglin and the pro-angiogenic vascular endothelial growth factor and placental growth factor, or stimulate the release of inflammatory cytokines, hypoxia-inducible factor, reactive oxygen species, and angiotensin AT1 receptor agonistic autoantibodies. These circulating factors could target MMPs in the extracellular matrix as well as endothelial and vascular smooth muscle cells, causing generalized vascular dysfunction, increased vasoconstriction and hypertension in pregnancy. MMP activity can also be altered by endogenous tissue inhibitors of metalloproteinases (TIMPs) and changes in the MMP/TIMP ratio. In addition to their vascular effects, decreases in expression/activity of MMP-2 and MMP-9 in the uterus could impede uterine growth and expansion and lead to premature labor. Understanding the role of MMPs in uteroplacental and

  18. Regioselectivity in the Reductive Bond Cleavage of Diarylalkylsulfonium Salts

    DEFF Research Database (Denmark)

    Kampmeier, Jack; Mansurul Hoque, AKM; D. Saeva, Franklin

    2009-01-01

    products vary from regiospecific alkyl cleavage to predominant aryl cleavage as a function of the potential of the reducing agent. We conclude that differences between the reductive cleavages of mono- and diarylsulfonium salts are direct consequences of the structures of the sulfuranyl radical......- tolylethylsulfonium and di-4-tolyl-2-phenylethylsulfonium salts by a variety of one-electron reducing agents ranging in potential from -0.77 to +2.5 eV (vs SCE) and including thermal reductants, indirect electrolyses mediated by a series of cyanoaromatics, and excited singlet states. We report that the cleavage...... intermediates and the bond dissociation energies of the alkyl and aryl bonds. Competitions between the rates of cleavage and oxidation of the intermediate sulfuranyl radicals and between concerted and stepwise mechanisms are discussed to explain the variations in bond cleavage products as a function...

  19. Kinetic analysis of the inhibition of matrix metalloproteinases: lessons from the study of tissue inhibitors of metalloproteinases.

    Science.gov (United States)

    Willenbrock, Frances; Thomas, Daniel A; Amour, Augustin

    2010-01-01

    Tissue inhibitors of metalloproteinases (TIMPs) are a group of highly potent inhibitors of matrix metalloproteinases (MMPs) and disintegrin metalloproteinases (ADAMs). The high affinity and "tight-binding" nature of the inhibition of MMPs or ADAMs by TIMPs presents challenges for the determination of both equilibrium and dissociation rate constants of these inhibitory events. Methodologies that enable some of these challenges to be overcome are described in this chapter and represent valuable lessons for the in vitro assessment of MMP or ADAM inhibitors within a drug discovery context.

  20. A Metalloproteinase Mirolysin of Tannerella forsythia Inhibits All Pathways of the Complement System

    DEFF Research Database (Denmark)

    Jusko, Monika; Potempa, Jan; Mizgalska, Danuta

    2015-01-01

    Recent reports focusing on virulence factors of periodontal pathogens implicated proteinases as major determinants of remarkable pathogenicity of these species, with special emphasis on their capacity to modulate complement activity. In particular, bacteria-mediated cleavage of C5 and subsequent...... release of C5a seems to be an important phenomenon in the manipulation of the local inflammatory response in periodontitis. In this study, we present mirolysin, a novel metalloproteinase secreted by Tannerella forsythia, a well-recognized pathogen strongly associated with periodontitis. Mirolysin...... with karilysin, as well as a cysteine proteinase of another periodontal pathogen, Prevotella intermedia, resulted in a strong synergistic effect on complement. Furthermore, mutant strains of T. forsythia, devoid of either mirolysin or karilysin, showed diminished survival in human serum, providing further...

  1. Cobalt (III) complexes as novel matrix metalloproteinase-9 inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jiyoun [Sungshin Women' s Univ., Seoul (Korea, Republic of)

    2012-04-15

    We have synthesized a series of novel MMP-9 inhibitors containing cobalt(III) complexes. The synthesized cobalt(III) complexes are effective as enzyme inhibitors and the attachment of a biphenyl group enhanced the efficiency of enzyme inhibition up to 6-fold. When compared to the reported non-hydroxamate MMP inhibitors, the synthesized complexes showed comparable in vitro potency. The enzyme assay showed that the cobalt(III) complex can disrupt the zinc binding active site of MMP-9 and is proposed to work via a ligand exchange mechanism. Since histidine residues are essential for the catalytic activity of a large percentage of enzymes and zinc finger proteins, these cobalt(III) complexes can serve as a prototype inhibitor towards various zinc containing enzymes and proteins. Matrix metalloproteinases (MMPs) are a family of zinc binding endopeptidases that play crucial roles in various physiological processes and diseases such as embryogenic growth, angiogenesis, arthritis, skin ulceration, liver fibrosis and tumor metastasis. Because of their implications in a wide range of diseases, MMPs are considered as intriguing drug targets. The majority of MMP inhibitors are organic small molecules containing a hydroxamate functionality for the zinc binding group. This hydroxamate group binds to a zinc(II) center in a bidentate fashion and creates a distorted trigonal bipyramidal geometry.

  2. Cobalt (III) complexes as novel matrix metalloproteinase-9 inhibitors

    International Nuclear Information System (INIS)

    Lee, Jiyoun

    2012-01-01

    We have synthesized a series of novel MMP-9 inhibitors containing cobalt(III) complexes. The synthesized cobalt(III) complexes are effective as enzyme inhibitors and the attachment of a biphenyl group enhanced the efficiency of enzyme inhibition up to 6-fold. When compared to the reported non-hydroxamate MMP inhibitors, the synthesized complexes showed comparable in vitro potency. The enzyme assay showed that the cobalt(III) complex can disrupt the zinc binding active site of MMP-9 and is proposed to work via a ligand exchange mechanism. Since histidine residues are essential for the catalytic activity of a large percentage of enzymes and zinc finger proteins, these cobalt(III) complexes can serve as a prototype inhibitor towards various zinc containing enzymes and proteins. Matrix metalloproteinases (MMPs) are a family of zinc binding endopeptidases that play crucial roles in various physiological processes and diseases such as embryogenic growth, angiogenesis, arthritis, skin ulceration, liver fibrosis and tumor metastasis. Because of their implications in a wide range of diseases, MMPs are considered as intriguing drug targets. The majority of MMP inhibitors are organic small molecules containing a hydroxamate functionality for the zinc binding group. This hydroxamate group binds to a zinc(II) center in a bidentate fashion and creates a distorted trigonal bipyramidal geometry

  3. Staggering in the cleavage pattern of E. coli ABC-excinuclease

    International Nuclear Information System (INIS)

    Myles, G.M.; Van Houten, B.; Sancar, A.

    1986-01-01

    E. coli ABC excinuclease is a complex of three proteins encoded by the uvrA, uvrB, and uvrC genes. The enzyme repairs DNA mono and diadducts by the single strand cleavage of DNA eight phosphodiester bond 5' and four or five phosphodiester bonds 3' to a DNA lesion and facilitates the removal of the resulting twelve or thirteen nucleotide fragment. In this study, the authors have investigated the excision pattern for ultraviolet (UV) induced diadducts, i.e. cyclobutane pyrimidine dimers and pyrimidine-pyrimidone (6-4) photoproducts. Terminally (5' or 3') labeled DNA was irradiated with 254nm UV and treated with ABC excinuclease before and after photoreactivation of cyclobutane dimers by E. coli DNA photolyase. In this way, the authors were able to differentiate between the cleavage pattern of pyrimidine dimers and of (6-4) photoproducts. Their results show that certain TT cyclobutane dimers and rare TT (6-4) photoproducts are excised by cleavage seven and, less frequently, six phosphodiester bonds to the 5' side of the DNA lesion in addition to the primary cutting site at the eight 5' phosphodiester bond. The 3' cleavage sites are maintained at the fourth and fifth phosphodiester bonds for the these UV induced lesions. These data indicate that the cleavage pattern of the ABC excinuclease may be dependent upon both the type of DNA lesion as well as it surrounding nucleotide sequence. In addition, the authors analysis shows that (6-4) photoproducts are much better substrates for ABC excinuclease than are pyrimidine dimers

  4. The dimer interfaces of protease and extra-protease domains influence the activation of protease and the specificity of GagPol cleavage.

    Science.gov (United States)

    Pettit, Steven C; Gulnik, Sergei; Everitt, Lori; Kaplan, Andrew H

    2003-01-01

    Activation of the human immunodeficiency virus type 1 (HIV-1) protease is an essential step in viral replication. As is the case for all retroviral proteases, enzyme activation requires the formation of protease homodimers. However, little is known about the mechanisms by which retroviral proteases become active within their precursors. Using an in vitro expression system, we have examined the determinants of activation efficiency and the order of cleavage site processing for the protease of HIV-1 within the full-length GagPol precursor. Following activation, initial cleavage occurs between the viral p2 and nucleocapsid proteins. This is followed by cleavage of a novel site located in the transframe domain. Mutational analysis of the dimer interface of the protease produced differential effects on activation and specificity. A subset of mutations produced enhanced cleavage at the amino terminus of the protease, suggesting that, in the wild-type precursor, cleavages that liberate the protease are a relatively late event. Replacement of the proline residue at position 1 of the protease dimer interface resulted in altered cleavage of distal sites and suggests that this residue functions as a cis-directed specificity determinant. In summary, our studies indicate that interactions within the protease dimer interface help determine the order of precursor cleavage and contribute to the formation of extended-protease intermediates. Assembly domains within GagPol outside the protease domain also influence enzyme activation.

  5. Preventing cleavage of Mer promotes efferocytosis and suppresses acute lung injury in bleomycin treated mice

    International Nuclear Information System (INIS)

    Lee, Ye-Ji; Lee, Seung-Hae; Youn, Young-So; Choi, Ji-Yeon; Song, Keung-Sub; Cho, Min-Sun; Kang, Jihee Lee

    2012-01-01

    Mer receptor tyrosine kinase (Mer) regulates macrophage activation and promotes apoptotic cell clearance. Mer activation is regulated through proteolytic cleavage of the extracellular domain. To determine if membrane-bound Mer is cleaved during bleomycin-induced lung injury, and, if so, how preventing the cleavage of Mer enhances apoptotic cell uptake and down-regulates pulmonary immune responses. During bleomycin-induced acute lung injury in mice, membrane-bound Mer expression decreased, but production of soluble Mer and activity as well as expression of disintegrin and metalloproteinase 17 (ADAM17) were enhanced . Treatment with the ADAM inhibitor TAPI-0 restored Mer expression and diminished soluble Mer production. Furthermore, TAPI-0 increased Mer activation in alveolar macrophages and lung tissue resulting in enhanced apoptotic cell clearance in vivo and ex vivo by alveolar macrophages. Suppression of bleomycin-induced pro-inflammatory mediators, but enhancement of hepatocyte growth factor induction were seen after TAPI-0 treatment. Additional bleomycin-induced inflammatory responses reduced by TAPI-0 treatment included inflammatory cell recruitment into the lungs, levels of total protein and lactate dehydrogenase activity in bronchoalveolar lavage fluid, as well as caspase-3 and caspase-9 activity and alveolar epithelial cell apoptosis in lung tissue. Importantly, the effects of TAPI-0 on bleomycin-induced inflammation and apoptosis were reversed by coadministration of specific Mer-neutralizing antibodies. These findings suggest that restored membrane-bound Mer expression by TAPI-0 treatment may help resolve lung inflammation and apoptosis after bleomycin treatment. -- Highlights: ►Mer expression is restored by TAPI-0 treatment in bleomycin-stimulated lung. ►Mer signaling is enhanced by TAPI-0 treatment in bleomycin-stimulated lung. ►TAPI-0 enhances efferocytosis and promotes resolution of lung injury.

  6. Restriction enzyme cleavage of ultraviolet-damaged Simian virus 40 and pBR322 DNA

    International Nuclear Information System (INIS)

    Cleaver, J.E.

    1983-01-01

    Cleavage of specific DNA sequences by the restriction enzymes EcoRI, HindIII and TaqI was prevented when the DNA was irradiated with ultraviolet light. Most of the effects were attributed to cyclobutane pyrimidine dimers in the recognition sequences; the effectiveness of irradiation was directly proportional to the number of potential dimer sites in the DNA. Combining EcoRI with dimer-specific endonuclease digestion revealed that pyrimidine dimers blocked cleavage within one base-pair on the strand opposite to the dimer but did not block cleavage three to four base-pairs away on the same strand. These are the probable limits for the range of influence of pyrimidine dimers along the DNA, at least for this enzyme. The effect of irradiation on cleavage by TaqI seemed far greater than expected for the cyclobutane dimer yield, possibly because of effects from photoproducts flanking the tetranucleotide recognition sequence and the effect of non-cyclobutane (6-4)pyrimidine photoproducts involving adjacent T and C bases. (author)

  7. Structural and functional basis for RNA cleavage by Ire1

    Directory of Open Access Journals (Sweden)

    Stroud Robert M

    2011-07-01

    Full Text Available Abstract Background The unfolded protein response (UPR controls the protein folding capacity of the endoplasmic reticulum (ER. Central to this signaling pathway is the ER-resident bifunctional transmembrane kinase/endoribonuclease Ire1. The endoribonuclease (RNase domain of Ire1 initiates a non-conventional mRNA splicing reaction, leading to the production of a transcription factor that controls UPR target genes. The mRNA splicing reaction is an obligatory step of Ire1 signaling, yet its mechanism has remained poorly understood due to the absence of substrate-bound crystal structures of Ire1, the lack of structural similarity between Ire1 and other RNases, and a scarcity of quantitative enzymological data. Here, we experimentally define the active site of Ire1 RNase and quantitatively evaluate the contribution of the key active site residues to catalysis. Results This analysis and two new crystal structures suggest that Ire1 RNase uses histidine H1061 and tyrosine Y1043 as the general acid-general base pair contributing ≥ 7.6 kcal/mol and 1.4 kcal/mol to transition state stabilization, respectively, and asparagine N1057 and arginine R1056 for coordination of the scissile phosphate. Investigation of the stem-loop recognition revealed that additionally to the stem-loops derived from the classic Ire1 substrates HAC1 and Xbp1 mRNA, Ire1 can site-specifically and rapidly cleave anticodon stem-loop (ASL of unmodified tRNAPhe, extending known substrate specificity of Ire1 RNase. Conclusions Our data define the catalytic center of Ire1 RNase and suggest a mechanism of RNA cleavage: each RNase monomer apparently contains a separate catalytic apparatus for RNA cleavage, whereas two RNase subunits contribute to RNA stem-loop docking. Conservation of the key residues among Ire1 homologues suggests that the mechanism elucidated here for yeast Ire1 applies to Ire1 in metazoan cells, and to the only known Ire1 homologue RNase L.

  8. Peptide-Based Selective Inhibitors of Matrix Metalloproteinase-Mediated Activities

    Directory of Open Access Journals (Sweden)

    Margaret W. Ndinguri

    2012-11-01

    Full Text Available The matrix metalloproteinases (MMPs exhibit a broad array of activities, some catalytic and some non-catalytic in nature. An overall lack of selectivity has rendered small molecule, active site targeted MMP inhibitors problematic in execution. Inhibitors that favor few or individual members of the MMP family often take advantage of interactions outside the enzyme active site. We presently focus on peptide-based MMP inhibitors and probes that do not incorporate conventional Zn2+ binding groups. In some cases, these inhibitors and probes function by binding only secondary binding sites (exosites, while others bind both exosites and the active site. A myriad of MMP mediated-activities beyond selective catalysis can be inhibited by peptides, particularly cell adhesion, proliferation, motility, and invasion. Selective MMP binding peptides comprise highly customizable, unique imaging agents. Areas of needed improvement for MMP targeting peptides include binding affinity and stability.

  9. Determinants of the VP1/2A junction cleavage by the 3C protease in foot-and-mouth disease virus-infected cells.

    Science.gov (United States)

    Kristensen, Thea; Normann, Preben; Gullberg, Maria; Fahnøe, Ulrik; Polacek, Charlotta; Rasmussen, Thomas Bruun; Belsham, Graham J

    2017-03-01

    The foot-and-mouth disease virus (FMDV) capsid precursor, P1-2A, is cleaved by FMDV 3C protease to yield VP0, VP3, VP1 and 2A. Cleavage of the VP1/2A junction is the slowest. Serotype O FMDVs with uncleaved VP1-2A (having a K210E substitution in VP1; at position P2 in cleavage site) have been described previously and acquired a second site substitution (VP1 E83K) during virus rescue. Furthermore, introduction of the VP1 E83K substitution alone generated a second site change at the VP1/2A junction (2A L2P, position P2' in cleavage site). These virus adaptations have now been analysed using next-generation sequencing to determine sub-consensus level changes in the virus; this revealed other variants within the E83K mutant virus population that changed residue VP1 K210. The construction of serotype A viruses with a blocked VP1/2A cleavage site (containing K210E) has now been achieved. A collection of alternative amino acid substitutions was made at this site, and the properties of the mutant viruses were determined. Only the presence of a positively charged residue at position P2 in the cleavage site permitted efficient cleavage of the VP1/2A junction, consistent with analyses of diverse FMDV genome sequences. Interestingly, in contrast to the serotype O virus results, no second site mutations occurred within the VP1 coding region of serotype A viruses with the blocked VP1/2A cleavage site. However, some of these viruses acquired changes in the 2C protein that is involved in enterovirus morphogenesis. These results have implications for the testing of potential antiviral agents targeting the FMDV 3C protease.

  10. Full Length Research Paper Curcumin induces cleavage of -catenin ...

    African Journals Online (AJOL)

    β-Catenin/Tcf-4 signaling pathway plays important roles in colorectal tumorigenesis. RT-PCR, western blotting and immunoprecipitation were used to study the effects of curcumin on β-catenin/Tcf-4 signaling pathway in HT-29 cells. Treatment of curcumin could induce cleavage of β-catenin and the cleavage could be ...

  11. Modeling and inferring cleavage patterns in proliferating epithelia.

    Directory of Open Access Journals (Sweden)

    Ankit B Patel

    2009-06-01

    Full Text Available The regulation of cleavage plane orientation is one of the key mechanisms driving epithelial morphogenesis. Still, many aspects of the relationship between local cleavage patterns and tissue-level properties remain poorly understood. Here we develop a topological model that simulates the dynamics of a 2D proliferating epithelium from generation to generation, enabling the exploration of a wide variety of biologically plausible cleavage patterns. We investigate a spectrum of models that incorporate the spatial impact of neighboring cells and the temporal influence of parent cells on the choice of cleavage plane. Our findings show that cleavage patterns generate "signature" equilibrium distributions of polygonal cell shapes. These signatures enable the inference of local cleavage parameters such as neighbor impact, maternal influence, and division symmetry from global observations of the distribution of cell shape. Applying these insights to the proliferating epithelia of five diverse organisms, we find that strong division symmetry and moderate neighbor/maternal influence are required to reproduce the predominance of hexagonal cells and low variability in cell shape seen empirically. Furthermore, we present two distinct cleavage pattern models, one stochastic and one deterministic, that can reproduce the empirical distribution of cell shapes. Although the proliferating epithelia of the five diverse organisms show a highly conserved cell shape distribution, there are multiple plausible cleavage patterns that can generate this distribution, and experimental evidence suggests that indeed plants and fruitflies use distinct division mechanisms.

  12. Matrix metalloproteinase activity assays: Importance of zymography.

    Science.gov (United States)

    Kupai, K; Szucs, G; Cseh, S; Hajdu, I; Csonka, C; Csont, T; Ferdinandy, P

    2010-01-01

    Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases capable of degrading extracellular matrix, including the basement membrane. MMPs are associated with various physiological processes such as morphogenesis, angiogenesis, and tissue repair. Moreover, due to the novel non-matrix related intra- and extracellular targets of MMPs, dysregulation of MMP activity has been implicated in a number of acute and chronic pathological processes, such as arthritis, acute myocardial infarction, chronic heart failure, chronic obstructive pulmonary disease, inflammation, and cancer metastasis. MMPs are considered as viable drug targets in the therapy of the above diseases. For the development of selective MMP inhibitor molecules, reliable methods are necessary for target validation and lead development. Here, we discuss the major methods used for MMP assays, focusing on substrate zymography. We highlight some problems frequently encountered during sample preparations, electrophoresis, and data analysis of zymograms. Zymography is a widely used technique to study extracellular matrix-degrading enzymes, such as MMPs, from tissue extracts, cell cultures, serum or urine. This simple and sensitive technique identifies MMPs by the degradation of their substrate and by their molecular weight and therefore helps to understand the widespread role of MMPs in different pathologies and cellular pathways. Copyright 2010 Elsevier Inc. All rights reserved.

  13. Matrix Metalloproteinases in Non-Neoplastic Disorders

    Science.gov (United States)

    Tokito, Akinori; Jougasaki, Michihisa

    2016-01-01

    The matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases belonging to the metzincin superfamily. There are at least 23 members of MMPs ever reported in human, and they and their substrates are widely expressed in many tissues. Recent growing evidence has established that MMP not only can degrade a variety of components of extracellular matrix, but also can cleave and activate various non-matrix proteins, including cytokines, chemokines and growth factors, contributing to both physiological and pathological processes. In normal conditions, MMP expression and activity are tightly regulated via interactions between their activators and inhibitors. Imbalance among these factors, however, results in dysregulated MMP activity, which causes tissue destruction and functional alteration or local inflammation, leading to the development of diverse diseases, such as cardiovascular disease, arthritis, neurodegenerative disease, as well as cancer. This article focuses on the accumulated evidence supporting a wide range of roles of MMPs in various non-neoplastic diseases and provides an outlook on the therapeutic potential of inhibiting MMP action. PMID:27455234

  14. Matrix metalloproteinases in exercise and obesity.

    Science.gov (United States)

    Jaoude, Jonathan; Koh, Yunsuk

    2016-01-01

    Matrix metalloproteinases (MMPs) are zinc- and calcium-dependent endoproteinases that have the ability to break down extracellular matrix. The large range of MMPs' functions widens their spectrum of potential role as activators or inhibitors in tissue remodeling, cardiovascular diseases, and obesity. In particular, MMP-1, -2, and -9 may be associated with exercise and obesity. Thus, the current study reviewed the effects of different types of exercise (resistance and aerobic) on MMP-1, -2, and -9. Previous studies report that the response of MMP-2 and -9 to resistance exercise is dependent upon the length of exercise training, since long-term resistance exercise training increased both MMP-2 and -9, whereas acute bout of resistance exercise decreased these MMPs. Aerobic exercise produces an inconsistent result on MMPs, although some studies showed a decrease in MMP-1. Obesity is related to a relatively lower level of MMP-9, indicating that an exercise-induced increase in MMP-9 may positively influence obesity. A comprehensive understanding of the relationship between exercise, obesity, and MMPs does not exist yet. Future studies examining the acute and chronic responses of these MMPs using different subject models may provide a better understanding of the molecular mechanisms that are associated with exercise, obesity, and cardiovascular disease.

  15. The matrix metalloproteinase in larynx cancer

    Directory of Open Access Journals (Sweden)

    Weronika Lucas Grzelczyk

    2016-12-01

    Full Text Available One of the most common carcinoma occurring in the head and neck is laryngeal cancer. Despite the rapid scientific advances in medicine the prognosis for patients with such type of disease is not satisfying. In the last few years matrix metalloproteinases ‑ MMPs and their tissue inhibitors – TIMPs, mostly MMP‑2 and MMP‑9, arouses a great interest, especially in the process of carcinogenesis. It seems that their impact in the formation and development of laryngeal cancer is significant. MMPs a group of zinc‑ and calcium‑ dependent endopeptidases play crucial role extracellular matrix collagen degradation. That are enzymes, that degrade and the basement membrane by facilitating tumor growth, cell migration and tumor invasion. They are implicated in metastasis and angiogenesis potentiate within the tumor. Clear tendency was observed towards the higher MMPs and TIMPs expression in larynx cancer than in the stroma. Recent studies show correlations between increased MMP‑2 gene expression in the tumor tissue and clinical status, histopathological grading and metastases occurrence. The similar MMP2 over expression dependence were found on tumor recurrence and survival. Many authors pointed out, significant higher MMP‑2 expression as a potential marker of tumor invasiveness and worse prognosis in patients with larynx cancer. However, association of MMP 9 gene expression with laryngeal cancer clinicopathological features and survival of patients are ambiguous. Although, numerous researches show that this relationship does exists. Similar correlations could be found in TIMPs, but further studies are necessary because of small amount of literature.

  16. PARP-1 cleavage fragments: signatures of cell-death proteases in neurodegeneration

    Directory of Open Access Journals (Sweden)

    Alexander Jonathan S

    2010-12-01

    Full Text Available Abstract The normal function of poly (ADP-ribose polymerase-1 (PARP-1 is the routine repair of DNA damage by adding poly (ADP ribose polymers in response to a variety of cellular stresses. Recently, it has become widely appreciated that PARP-1 also participates in diverse physiological and pathological functions from cell survival to several forms of cell death and has been implicated in gene transcription, immune responses, inflammation, learning, memory, synaptic functions, angiogenesis and aging. In the CNS, PARP inhibition attenuates injury in pathologies like cerebral ischemia, trauma and excitotoxicity demonstrating a central role of PARP-1 in these pathologies. PARP-1 is also a preferred substrate for several 'suicidal' proteases and the proteolytic action of suicidal proteases (caspases, calpains, cathepsins, granzymes and matrix metalloproteinases (MMPs on PARP-1 produces several specific proteolytic cleavage fragments with different molecular weights. These PARP-1 signature fragments are recognized biomarkers for specific patterns of protease activity in unique cell death programs. This review focuses on specific suicidal proteases active towards PARP-1 to generate signature PARP-1 fragments that can identify key proteases and particular forms of cell death involved in pathophysiology. The roles played by some of the PARP-1 fragments and their associated binding partners in the control of different forms of cell death are also discussed.

  17. The Generation of Dehydroalanine Residues in Protonated Polypeptides: Ion/Ion Reactions for Introducing Selective Cleavages

    Science.gov (United States)

    Peng, Zhou; Bu, Jiexun; McLuckey, Scott A.

    2017-09-01

    We examine a gas-phase approach for converting a subset of amino acid residues in polypeptide cations to dehydroalanine (Dha). Subsequent activation of the modified polypeptide ions gives rise to specific cleavage N-terminal to the Dha residue. This process allows for the incorporation of selective cleavages in the structural characterization of polypeptide ions. An ion/ion reaction within the mass spectrometer between a multiply protonated polypeptide and the sulfate radical anion introduces a radical site into the multiply protonated polypeptide reactant. Subsequent collisional activation of the polypeptide radical cation gives rise to radical side chain loss from one of several particular amino acid side chains (e.g., leucine, asparagine, lysine, glutamine, and glutamic acid) to yield a Dha residue. The Dha residues facilitate preferential backbone cleavages to produce signature c- and z-ions, demonstrated with cations derived from melittin, mechano growth factor (MGF), and ubiquitin. The efficiencies for radical side chain loss and for subsequent generation of specific c- and z-ions have been examined as functions of precursor ion charge state and activation conditions using cations of ubiquitin as a model for a small protein. It is noted that these efficiencies are not strongly dependent on ion trap collisional activation conditions but are sensitive to precursor ion charge state. Moderate to low charge states show the greatest overall yields for the specific Dha cleavages, whereas small molecule losses (e.g., water/ammonia) dominate at the lowest charge states and proton catalyzed amide bond cleavages that give rise to b- and y-ions tend to dominate at high charge states. [Figure not available: see fulltext.

  18. Maximizing Selective Cleavages at Aspartic Acid and Proline Residues for the Identification of Intact Proteins

    Science.gov (United States)

    Foreman, David J.; Dziekonski, Eric T.; McLuckey, Scott A.

    2018-04-01

    A new approach for the identification of intact proteins has been developed that relies on the generation of relatively few abundant products from specific cleavage sites. This strategy is intended to complement standard approaches that seek to generate many fragments relatively non-selectively. Specifically, this strategy seeks to maximize selective cleavage at aspartic acid and proline residues via collisional activation of precursor ions formed via electrospray ionization (ESI) under denaturing conditions. A statistical analysis of the SWISS-PROT database was used to predict the number of arginine residues for a given intact protein mass and predict a m/z range where the protein carries a similar charge to the number of arginine residues thereby enhancing cleavage at aspartic acid residues by limiting proton mobility. Cleavage at aspartic acid residues is predicted to be most favorable in the m/z range of 1500-2500, a range higher than that normally generated by ESI at low pH. Gas-phase proton transfer ion/ion reactions are therefore used for precursor ion concentration from relatively high charge states followed by ion isolation and subsequent generation of precursor ions within the optimal m/z range via a second proton transfer reaction step. It is shown that the majority of product ion abundance is concentrated into cleavages C-terminal to aspartic acid residues and N-terminal to proline residues for ions generated by this process. Implementation of a scoring system that weights both ion fragment type and ion fragment area demonstrated identification of standard proteins, ranging in mass from 8.5 to 29.0 kDa. [Figure not available: see fulltext.

  19. Expressions of matrix metalloproteinase-2 and extracellular matrix metalloproteinase inducer in retinoblastoma

    Directory of Open Access Journals (Sweden)

    Yu-Hong Cheng

    2015-07-01

    Full Text Available AIM: To investigate expressions of matrix metalloproteinase-2(MMP-2and extracellular matrix metalloproteinase inducer(EMMPRINin retinoblastoma(Rband the relationships between MMP-2, EMMPRIN and tumor development.METHODS:Immunohistochemical technique was used to detect expressions of MMP-2 and EMMPRIN in 39 cases of paraffin embedded Rb samples. Quantitative analysis of expressions of MMP-2 and EMMPRIN were assessed by measuring the mean gray scale of Rb tissue with LEICA IM50 Color Pathologic Analysis System. The differences of expressions of MMP-2 and EMMPRIN in each clinical and pathological stage were statistically analyzed, and the same step was also undertaken to study the relationship between Rb with MMP-2 positive expression and that with EMMPRIN positive expression.RESULTS: The positive expression rate of MMP-2 was 90%(Gray value: 109.64±14.52; 35/39, and that of EMMPRIN was 85%(Gray value: 108.01±13.60; 33/39. The expressions of MMP-2 and EMMPRIN were significantly higher in tumors of glaucomatous stage(Gray value: 108.21±11.47 and 107.56±14.32than those in intraocular stage(Gray value: 121.13±11.32 and 119.34±12.66; PPPPPPCONCLUSION: The positive expression levels of MMP-2 and EMMPRIN may correlate with tumor infiltration and metastasis.

  20. Proliferative effects of apical, but not basal, matrix metalloproteinase-7 activity in polarized MDCK cells

    International Nuclear Information System (INIS)

    Harrell, Permila C.; McCawley, Lisa J.; Fingleton, Barbara; McIntyre, J. Oliver; Matrisian, Lynn M.

    2005-01-01

    Matrix metalloproteinase-7 (MMP-7) is primarily expressed in glandular epithelium. Therefore, its mechanism of action may be influenced by its regulated vectorial release to either the apical and/or basolateral compartments, where it would act on its various substrates. To gain a better understanding of where MMP-7 is released in polarized epithelium, we have analyzed its pattern of secretion in polarized MDCK cells expressing stably transfected human MMP-7 (MDCK-MMP-7), and HCA-7 and Caco2 human colon cancer cell lines. In all cell lines, latent MMP-7 was secreted to both cellular compartments, but was 1.5- to 3-fold more abundant in the basolateral compartment as compared to the apical. However, studies in the MDCK system demonstrated that MMP-7 activity was 2-fold greater in the apical compartment of MDCK-MMP-7 HIGH -polarized monolayers, which suggests the apical co-release of an MMP-7 activator. In functional assays, MMP-7 over-expression increased cell saturation density as a result of increased cell proliferation with no effect on apoptosis. Apical MMP-7 activity was shown to be responsible for the proliferative effect, which occurred, as demonstrated by media transfer experiments, through cleavage of an apical substrate and not through the generation of a soluble factor. Taken together, our findings demonstrate the importance of MMP-7 secretion in relation to its mechanism of action when expressed in a polarized epithelium

  1. cDNA cloning of a snake venom metalloproteinase from the eastern diamondback rattlesnake (Crotalus adamanteus), and the expression of its disintegrin domain with anti-platelet effects

    Science.gov (United States)

    Suntravat, Montamas; Jia, Ying; Lucena, Sara E.; Sánchez, Elda E.; Pérez, John C.

    2013-01-01

    A 5′ truncated snake venom metalloproteinase was identified from a cDNA library constructed from venom glands of an eastern diamondback rattlesnake (Crotalus adamanteus). The 5′-rapid amplification of cDNA ends (RACE) was used to obtain the 1865 bp full-length cDNA sequence of a snake venom metalloproteinase (CamVMPII). CamVMPII encodes an open reading frame of 488 amino acids, which includes a signal peptide, a pro-domain, a metalloproteinase domain, a spacer, and an RGD-disintegrin domain. The predicted amino acid sequence of CamVMPII showed a 91%, 90%, 83%, and 82% sequence homology to the P-II class enzymes of C. adamanteus metalloproteinase 2, C. atrox CaVMP-II, Gloydius halys agkistin, and Protobothrops jerdonii jerdonitin, respectively. Disintegrins are potent inhibitors of both platelet aggregation and integrin-dependent cell adhesion. Therefore, the disintegrin domain (Cam-dis) of CamVMPII was amplified by PCR, cloned into a pET-43.1a vector, and expressed in Escherichia coli BL21. Affinity purified recombinantly modified Cam-dis (r-Cam-dis) with a yield of 8.5 mg/L culture medium was cleaved from the fusion tags by enterokinase cleavage. r-Cam-dis was further purified by two-step chromatography consisting of HiTrap™ Benzamidine FF column, followed by Talon Metal affinity column with a final yield of 1 mg/L culture. r-Cam-dis was able to inhibit all three processes of platelet thrombus formation including platelet adhesion with an estimated IC50 of 1 nM, collagen- and ADP-induced platelet aggregation with the estimated IC50s of 18 and 6 nM, respectively, and platelet function on clot retraction. It is a potent anti-platelet inhibitor, which should be further investigated for drug discovery to treat stroke patients or patients with thrombotic disorders. PMID:23313448

  2. Porcine deltacoronavirus nsp5 inhibits interferon-β production through the cleavage of NEMO.

    Science.gov (United States)

    Zhu, Xinyu; Fang, Liurong; Wang, Dang; Yang, Yuting; Chen, Jiyao; Ye, Xu; Foda, Mohamed Frahat; Xiao, Shaobo

    2017-02-01

    Porcine deltacoronavirus (PDCoV) causes acute enteric disease and mortality in seronegative neonatal piglets. Previously we have demonstrated that PDCoV infection suppresses the production of interferon-beta (IFN-β), while the detailed mechanisms are poorly understood. Here, we demonstrate that nonstructural protein 5 (nsp5) of PDCoV, the 3C-like protease, significantly inhibits Sendai virus (SEV)-induced IFN-β production by targeting the NF-κB essential modulator (NEMO), confirmed by the diminished function of NEMO cleaved by PDCoV. The PDCoV nsp5 cleavage site in the NEMO protein was identified as glutamine 231, and was identical to the porcine epidemic diarrhea virus nsp5 cleavage site, revealing the likelihood of a common target in NEMO for coronaviruses. Furthermore, this cleavage impaired the ability of NEMO to activate the IFN response and downstream signaling. Taken together, our findings reveal PDCoV nsp5 to be a newly identified IFN antagonist and enhance the understanding of immune evasion by deltacoronaviruses. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Quantification of DNA cleavage specificity in Hi-C experiments.

    Science.gov (United States)

    Meluzzi, Dario; Arya, Gaurav

    2016-01-08

    Hi-C experiments produce large numbers of DNA sequence read pairs that are typically analyzed to deduce genomewide interactions between arbitrary loci. A key step in these experiments is the cleavage of cross-linked chromatin with a restriction endonuclease. Although this cleavage should happen specifically at the enzyme's recognition sequence, an unknown proportion of cleavage events may involve other sequences, owing to the enzyme's star activity or to random DNA breakage. A quantitative estimation of these non-specific cleavages may enable simulating realistic Hi-C read pairs for validation of downstream analyses, monitoring the reproducibility of experimental conditions and investigating biophysical properties that correlate with DNA cleavage patterns. Here we describe a computational method for analyzing Hi-C read pairs to estimate the fractions of cleavages at different possible targets. The method relies on expressing an observed local target distribution downstream of aligned reads as a linear combination of known conditional local target distributions. We validated this method using Hi-C read pairs obtained by computer simulation. Application of the method to experimental Hi-C datasets from murine cells revealed interesting similarities and differences in patterns of cleavage across the various experiments considered. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  4. Zymographic techniques for the analysis of matrix metalloproteinases and their inhibitors.

    NARCIS (Netherlands)

    Snoek, P.A.; Hoff, J.W. Von den

    2005-01-01

    The balance between matrix metalloproteinases (MMPs) and their inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), is largely responsible for the remodeling of tissues. Deregulation of this balance is a characteristic of extensive tissue degradation in certain degenerative diseases. To

  5. A Subset of Membrane-Altering Agents and γ-Secretase Modulators Provoke Nonsubstrate Cleavage by Rhomboid Proteases

    Directory of Open Access Journals (Sweden)

    Siniša Urban

    2014-09-01

    Full Text Available Rhomboid proteases are integral membrane enzymes that regulate cell signaling, adhesion, and organelle homeostasis pathways, making substrate specificity a key feature of their function. Interestingly, we found that perturbing the membrane pharmacologically in living cells had little effect on substrate processing but induced inappropriate cleavage of nonsubstrates by rhomboid proteases. A subclass of drugs known to modulate γ-secretase activity acted on the membrane directly and induced nonsubstrate cleavage by rhomboid proteases but left true substrate cleavage sites unaltered. These observations highlight an active role for the membrane in guiding rhomboid selectivity and caution that membrane-targeted drugs should be evaluated for cross-activity against membrane-resident enzymes that are otherwise unrelated to the intended drug target. Furthermore, some γ-secretase-modulating activity or toxicity could partly result from global membrane effects.

  6. Metalloproteinase inhibition prevents acute respiratory distress syndrome.

    Science.gov (United States)

    Carney, D E; McCann, U G; Schiller, H J; Gatto, L A; Steinberg, J; Picone, A L; Nieman, G F

    2001-08-01

    The acute respiratory distress syndrome (ARDS) occurs in patients with clearly identifiable risk factors, and its treatment remains merely supportive. We postulated that patients at risk for ARDS can be protected against lung injury by a prophylactic treatment strategy that targets neutrophil-derived proteases. We hypothesized that a chemically modified tetracycline 3 (COL-3), a potent inhibitor of neutrophil matrix metalloproteinases (MMPs) and neutrophil elastase (NE) with minimal toxicity, would prevent ARDS in our porcine endotoxin-induced ARDS model. Yorkshire pigs were anesthetized, intubated, surgically instrumented for hemodynamic monitoring, and randomized into three groups: (1) control (n = 4), surgical instrumentation only; (2) lipopolysaccharide (LPS) (n = 4), infusion of Escherichia coli lipopolysaccharide at 100 microg/kg; and (3) COL-3 + LPS (n = 5), ingestion of COL-3 (100 mg/kg) 12 h before LPS infusion. All animals were monitored for 6 h following LPS or sham LPS infusion. Serial bronchoalveolar lavage (BAL) samples were analyzed for MMP concentration by gelatin zymography. Lung tissue was fixed for morphometric assessment at necropsy. LPS infusion was marked by significant (P decrement in arterial oxygen partial pressure (P(a)O(2)) (LPS = 66 +/- 15 mm Hg, Control = 263 +/- 25 mm Hg) 6 h following LPS or sham LPS infusion, respectively. Pretreatment with COL-3 reduced the above pathophysiological changes 6 h following LPS infusion (P(plat) = 18.5 +/- 1.7 mm Hg, P(a)O(2) = 199 +/- 35 mm Hg; P = NS vs control). MMP-9 and MMP-2 concentration in BAL fluid was significantly increased between 2 and 4 h post-LPS infusion; COL-3 reduced the increase in MMP-9 and MMP-2 concentration at all time periods. Morphometrically LPS caused a significant sequestration of neutrophils and monocytes into pulmonary tissue. Pretreatment with COL-3 ameliorated this response. The wet/dry lung weight ratio was significantly greater (P single prophylactic treatment with COL

  7. Implementation of a combinatorial cleavage and deprotection scheme

    DEFF Research Database (Denmark)

    Nielsen, John; Rasmussen, Palle H.

    1996-01-01

    Phthalhydrazide libraries are synthesized in solution from substituted hydrazines and phthalimides in several different library formats including single compounds, indexed sub-libraries and a full library. When carried out during solid-phase synthesis, this combinatorial cleavage and deprotection...

  8. Stimuli-Responsive Nanodiamond-Based Biosensor for Enhanced Metastatic Tumor Site Detection.

    Science.gov (United States)

    Wang, Xin; Gu, Mengjie; Toh, Tan Boon; Abdullah, Nurrul Lissa Binti; Chow, Edward Kai-Hua

    2018-02-01

    Metastasis is often critical to cancer progression and linked to poor survival and drug resistance. Early detection of metastasis, as well as identification of metastatic tumor sites, can improve cancer patient survival. Thus, developing technology to improve the detection of cancer metastasis biomarkers can improve both diagnosis and treatment. In this study, we investigated the use of nanodiamonds to develop a stimuli-responsive metastasis detection complex that utilizes matrix metalloproteinase 9 (MMP9) as a metastasis biomarker, as MMP9 increased expression has been shown to be indicative of metastasis. The nanodiamond-MMP9 biosensor complex consists of nanodiamonds functionalized with MMP9-specific fluorescent-labeled substrate peptides. Using this design, protease activity of MMP9 can be accurately measured and correlated to MMP9 expression. The nanodiamond-MMP9 biosensor also demonstrated an enhanced ability to protect the base sensor peptide from nonspecific serum protease cleavage. This enhanced peptide stability, combined with a quantitative stimuli-responsive output function, provides strong evidence for the further development of a nanodiamond-MMP9 biosensor for metastasis site detection. More importantly, this work provides the foundation for use of nanodiamonds as a platform for stimuli-responsive biosensors and theranostic complexes that can be implemented across a wide range of biomedical applications.

  9. Cleavage events and sperm dynamics in chick intrauterine embryos.

    Directory of Open Access Journals (Sweden)

    Hyung Chul Lee

    Full Text Available This study was undertaken to elucidate detailed event of early embryogenesis in chicken embryos using a noninvasive egg retrieval technique before oviposition. White Leghorn intrauterine eggs were retrieved from 95 cyclic hens aged up to 54-56 weeks and morphogenetic observation was made under both bright field and fluorescent image in a time course manner. Differing from mammals, asymmetric cleavage to yield preblastodermal cells was observed throughout early embryogenesis. The first two divisions occurred synchronously and four polarized preblastodermal cells resulted after cruciform cleavage. Then, asynchronous cleavage continued in a radial manner and overall cell size in the initial cleavage region was smaller than that in the distal area. Numerous sperms were visible, regardless of zygotic nuclei formation. Condensed sperm heads were present mainly in the perivitelline space and cytoplasm, and rarely in the yolk region, while decondensed sperm heads were only visible in the yolk. In conclusion, apparent differences in sperm dynamics and early cleavage events compared with mammalian embryos were detected in chick embryo development, which demonstrated polarized cleavage with penetrating supernumerary sperm into multiple regions.

  10. Dynamics of bleomycin interaction with a strongly bound hairpin DNA substrate, and implications for cleavage of the bound DNA.

    Science.gov (United States)

    Bozeman, Trevor C; Nanjunda, Rupesh; Tang, Chenhong; Liu, Yang; Segerman, Zachary J; Zaleski, Paul A; Wilson, W David; Hecht, Sidney M

    2012-10-31

    Recent studies involving DNAs bound strongly by bleomycins have documented that such DNAs are degraded by the antitumor antibiotic with characteristics different from those observed when studying the cleavage of randomly chosen DNAs in the presence of excess Fe·BLM. In the present study, surface plasmon resonance has been used to characterize the dynamics of BLM B(2) binding to a strongly bound hairpin DNA, to define the effects of Fe(3+), salt, and temperature on BLM-DNA interaction. One strong primary DNA binding site, and at least one much weaker site, were documented. In contrast, more than one strong cleavage site was found, an observation also made for two other hairpin DNAs. Evidence is presented for BLM equilibration between the stronger and weaker binding sites in a way that renders BLM unavailable to other, less strongly bound DNAs. Thus, enhanced binding to a given site does not necessarily result in increased DNA degradation at that site; i.e., for strongly bound DNAs, the facility of DNA cleavage must involve other parameters in addition to the intrinsic rate of C-4' H atom abstraction from DNA sugars.

  11. SKI2 mediates degradation of RISC 5′-cleavage fragments and prevents secondary siRNA production from miRNA targets in Arabidopsis

    Science.gov (United States)

    Branscheid, Anja; Marchais, Antonin; Schott, Gregory; Lange, Heike; Gagliardi, Dominique; Andersen, Stig Uggerhøj; Voinnet, Olivier; Brodersen, Peter

    2015-01-01

    Small regulatory RNAs are fundamental in eukaryotic and prokaryotic gene regulation. In plants, an important element of post-transcriptional control is effected by 20–24 nt microRNAs (miRNAs) and short interfering RNAs (siRNAs) bound to the ARGONAUTE1 (AGO1) protein in an RNA induced silencing complex (RISC). AGO1 may cleave target mRNAs with small RNA complementarity, but the fate of the resulting cleavage fragments remains incompletely understood. Here, we show that SKI2, SKI3 and SKI8, subunits of a cytoplasmic cofactor of the RNA exosome, are required for degradation of RISC 5′, but not 3′-cleavage fragments in Arabidopsis. In the absence of SKI2 activity, many miRNA targets produce siRNAs via the RNA-dependent RNA polymerase 6 (RDR6) pathway. These siRNAs are low-abundant, and map close to the cleavage site. In most cases, siRNAs were produced 5′ to the cleavage site, but several examples of 3′-spreading were also identified. These observations suggest that siRNAs do not simply derive from RDR6 action on stable 5′-cleavage fragments and hence that SKI2 has a direct role in limiting secondary siRNA production in addition to its function in mediating degradation of 5′-cleavage fragments. PMID:26464441

  12. SKI2 mediates degradation of RISC 5'-cleavage fragments and prevents secondary siRNA production from miRNA targets in Arabidopsis.

    Science.gov (United States)

    Branscheid, Anja; Marchais, Antonin; Schott, Gregory; Lange, Heike; Gagliardi, Dominique; Andersen, Stig Uggerhøj; Voinnet, Olivier; Brodersen, Peter

    2015-12-15

    Small regulatory RNAs are fundamental in eukaryotic and prokaryotic gene regulation. In plants, an important element of post-transcriptional control is effected by 20-24 nt microRNAs (miRNAs) and short interfering RNAs (siRNAs) bound to the ARGONAUTE1 (AGO1) protein in an RNA induced silencing complex (RISC). AGO1 may cleave target mRNAs with small RNA complementarity, but the fate of the resulting cleavage fragments remains incompletely understood. Here, we show that SKI2, SKI3 and SKI8, subunits of a cytoplasmic cofactor of the RNA exosome, are required for degradation of RISC 5', but not 3'-cleavage fragments in Arabidopsis. In the absence of SKI2 activity, many miRNA targets produce siRNAs via the RNA-dependent RNA polymerase 6 (RDR6) pathway. These siRNAs are low-abundant, and map close to the cleavage site. In most cases, siRNAs were produced 5' to the cleavage site, but several examples of 3'-spreading were also identified. These observations suggest that siRNAs do not simply derive from RDR6 action on stable 5'-cleavage fragments and hence that SKI2 has a direct role in limiting secondary siRNA production in addition to its function in mediating degradation of 5'-cleavage fragments. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  13. Matrix metalloproteinase-8 overexpression prevents proper tissue repair

    DEFF Research Database (Denmark)

    Danielsen, Patricia L; Holst, Anders V; Maltesen, Henrik R

    2011-01-01

    The collagenolytic matrix metalloproteinase-8 (MMP-8) is essential for normal tissue repair but is often overexpressed in wounds with disrupted healing. Our aim was to study the impact of a local excess of this neutrophil-derived proteinase on wound healing using recombinant adenovirus...

  14. Role of matrix metalloproteinases in recurrent corneal melting

    Czech Academy of Sciences Publication Activity Database

    Brejchová, K.; Lisková, P.; Čejková, Jitka; Jirsová, K.

    2010-01-01

    Roč. 90, č. 5 (2010), s. 583-590 ISSN 0014-4835 Institutional research plan: CEZ:AV0Z50390512 Keywords : corneal melting * extracellular matrix degradation * matrix metalloproteinases Subject RIV: FF - HEENT, Dentistry Impact factor: 2.817, year: 2010

  15. Snake venom metalloproteinases and disintegrins: interactions with cells

    Directory of Open Access Journals (Sweden)

    Kamiguti A.S.

    1998-01-01

    Full Text Available Metalloproteinases and disintegrins are important components of most viperid and crotalid venoms. Large metalloproteinases referred to as MDC enzymes are composed of an N-terminal Metalloproteinase domain, a Disintegrin-like domain and a Cys-rich C-terminus. In contrast, disintegrins are small non-enzymatic RGD-containing cysteine-rich polypeptides. However, the disintegrin region of MDC enzymes bears a high degree of structural homology to that of the disintegrins, although it lacks the RGD motif. Despite these differences, both components share the property of being able to recognize integrin cell surface receptors and thereby to inhibit integrin-dependent cell reactions. Recently, several membrane-bound MDC enzymes, closely related to soluble venom MDC enzymes, have been described in mammalian cells. This group of membrane-anchored mammalian enzymes is also called the ADAM family of proteins due to the structure revealing A Disintegrin And Metalloproteinase domains. ADAMs are involved in the shedding of molecules from the cell surface, a property which is also shared by some venom MDC enzymes.

  16. Inhibition of matrix metalloproteinase-14 in osteosarcoma cells by clodronate

    NARCIS (Netherlands)

    Heikkilä, P.; Teronen, O.; Hirn, M.Y.; Sorsa, T.; Tervahartiala, T.; Salo, T.; Konttinen, Y.T.; Halttunen, T.; Moilanen, M.; Hanemaaijer, R.; Laitinen, M.

    2003-01-01

    Background. Bisphosphonates reduce the bone metastasis formation and angiogenesis but the exact molecular mechanisms involved are unclear. Progelatinase A (proMMP-2; 78 KDa) is activated up during the tumor spread and metastasis by a cell surface-associated matrix metalloproteinase (membrane-type

  17. Plasma tissue inhibitor of metalloproteinases-1 as a biological marker?

    DEFF Research Database (Denmark)

    Lomholt, Anne F.; Frederiksen, Camilla B.; Christensen, Ib J.

    2007-01-01

    Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) may be a valuable biological marker in Colorectal Cancer (CRC). However, prospective validation of TIMP-1 as a biological marker should include a series of pre-analytical considerations. TIMP-1 is stored in platelets, which may degranulate during...

  18. Spontaneous metastasis in matrix metalloproteinase 3-deficient mice

    DEFF Research Database (Denmark)

    Juncker-Jensen, Anna; Rømer, John; Pennington, Caroline J

    2009-01-01

    Matrix metalloproteinases (MMPs) have been linked to the metastatic potential of tumor cells due to their ability to degrade the extracellular matrix. MMP-3 (stromelysin-1) is upregulated in a wide variety of human tumors. We used the MMTV-PyMT breast cancer model to determine if MMP-3 is involved...

  19. Cas9-catalyzed DNA Cleavage Generates Staggered Ends: Evidence from Molecular Dynamics Simulations

    Science.gov (United States)

    Zuo, Zhicheng; Liu, Jin

    2016-11-01

    The CRISPR-associated endonuclease Cas9 from Streptococcus pyogenes (spCas9) along with a single guide RNA (sgRNA) has emerged as a versatile toolbox for genome editing. Despite recent advances in the mechanism studies on spCas9-sgRNA-mediated double-stranded DNA (dsDNA) recognition and cleavage, it is still unclear how the catalytic Mg2+ ions induce the conformation changes toward the catalytic active state. It also remains controversial whether Cas9 generates blunt-ended or staggered-ended breaks with overhangs in the DNA. To investigate these issues, here we performed the first all-atom molecular dynamics simulations of the spCas9-sgRNA-dsDNA system with and without Mg2+ bound. The simulation results showed that binding of two Mg2+ ions at the RuvC domain active site could lead to structurally and energetically favorable coordination ready for the non-target DNA strand cleavage. Importantly, we demonstrated with our simulations that Cas9-catalyzed DNA cleavage produces 1-bp staggered ends rather than generally assumed blunt ends.

  20. Direct Fibrinolytic Snake Venom Metalloproteinases Affecting Hemostasis: Structural, Biochemical Features and Therapeutic Potential.

    Science.gov (United States)

    Sanchez, Eladio F; Flores-Ortiz, Renzo J; Alvarenga, Valeria G; Eble, Johannes A

    2017-12-05

    Snake venom metalloproteinases (SVMPs) are predominant in viperid venoms, which provoke hemorrhage and affect hemostasis and thrombosis. P-I class enzymes consist only of a single metalloproteinase domain. Despite sharing high sequence homology, only some of them induce hemorrhage. They have direct fibrin(ogen)olytic activity. Their main biological substrate is fibrin(ogen), whose Aα-chain is degraded rapidly and independently of activation of plasminogen. It is important to understand their biochemical and physiological mechanisms, as well as their applications, to study the etiology of some human diseases and to identify sites of potential intervention. As compared to all current antiplatelet therapies to treat cardiovascular events, the SVMPs have outstanding biochemical attributes: (a) they are insensitive to plasma serine proteinase inhibitors; (b) they have the potential to avoid bleeding risk; (c) mechanistically, they are inactivated/cleared by α2-macroglobulin that limits their range of action in circulation; and (d) few of them also impair platelet aggregation that represent an important target for therapeutic intervention. This review will briefly highlight the structure-function relationships of these few direct-acting fibrinolytic agents, including, barnettlysin-I, isolated from Bothrops barnetti venom, that could be considered as potential agent to treat major thrombotic disorders. Some of their pharmacological advantages are compared with plasmin.

  1. Direct Fibrinolytic Snake Venom Metalloproteinases Affecting Hemostasis: Structural, Biochemical Features and Therapeutic Potential

    Directory of Open Access Journals (Sweden)

    Eladio F. Sanchez

    2017-12-01

    Full Text Available Snake venom metalloproteinases (SVMPs are predominant in viperid venoms, which provoke hemorrhage and affect hemostasis and thrombosis. P-I class enzymes consist only of a single metalloproteinase domain. Despite sharing high sequence homology, only some of them induce hemorrhage. They have direct fibrin(ogenolytic activity. Their main biological substrate is fibrin(ogen, whose Aα-chain is degraded rapidly and independently of activation of plasminogen. It is important to understand their biochemical and physiological mechanisms, as well as their applications, to study the etiology of some human diseases and to identify sites of potential intervention. As compared to all current antiplatelet therapies to treat cardiovascular events, the SVMPs have outstanding biochemical attributes: (a they are insensitive to plasma serine proteinase inhibitors; (b they have the potential to avoid bleeding risk; (c mechanistically, they are inactivated/cleared by α2-macroglobulin that limits their range of action in circulation; and (d few of them also impair platelet aggregation that represent an important target for therapeutic intervention. This review will briefly highlight the structure–function relationships of these few direct-acting fibrinolytic agents, including, barnettlysin-I, isolated from Bothrops barnetti venom, that could be considered as potential agent to treat major thrombotic disorders. Some of their pharmacological advantages are compared with plasmin.

  2. Determinants of the VP1/2A junction cleavage by the 3C protease in foot-and-mouth disease virus infected cells

    DEFF Research Database (Denmark)

    Kristensen, Thea; Normann, Preben; Gullberg, Maria

    2017-01-01

    . Interestingly, in contrast to the serotype O virus results, no second site mutations occurred within the VP1 coding region of serotype A viruses with the blocked VP1/2A cleavage site. However, some of these viruses acquired changes in the 2C protein that is involved in enterovirus morphogenesis. These results...

  3. Peptidomimetic hydroxamate metalloproteinase inhibitors abrogate local and systemic toxicity induced by Echis ocellatus (saw-scaled) snake venom.

    Science.gov (United States)

    Arias, Ana Silvia; Rucavado, Alexandra; Gutiérrez, José María

    2017-06-15

    The ability of two peptidomimetic hydroxamate metalloproteinase inhibitors, Batimastat and Marimastat, to abrogate toxic and proteinase activities of the venom of Echis ocellatus from Cameroon and Ghana was assessed. Since this venom largely relies for its toxicity on the action of zinc-dependent metalloproteinases (SVMPs), the hypothesis was raised that toxicity could be largely eliminated by using SVMP inhibitors. Both hydroxamate molecules inhibited local and pulmonary hemorrhagic, in vitro coagulant, defibrinogenating, and proteinase activities of the venoms in conditions in which venom and inhibitors were incubated prior to the test. In addition, the inhibitors prolonged the time of death of mice receiving 4 LD 50 s of venom by the intravenous route. Lower values of IC 50 were observed for in vitro and local hemorrhagic activities than for systemic effects. When experiments were performed in conditions that simulated the actual circumstances of snakebite, i.e. by administering the inhibitor after envenoming, Batimastat completely abrogated local hemorrhage if injected immediately after venom. Moreover, it was also effective at inhibiting lethality and defibrinogenation when venom and inhibitor were injected by the intraperitoneal route. Results suggest that these, and possibly other, metalloproteinase inhibitors may become an effective adjunct therapy in envenomings by E. ocellatus when administered at the anatomic site of venom injection rapidly after the bite. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4.  The role of metalloproteinases in modification of extracellular matrix in invasive tumor growth, metastasis and angiogenesis

    Directory of Open Access Journals (Sweden)

    Krzysztof Fink

    2012-09-01

    Full Text Available Extracellular matrix metalloproteinases (MMPs are a family of endopeptydases which recquire a zinc ion at their active site, for proteolityc activity. There are six members of the MMP family: matrilysins, collagenases, stromelysins, gelatinases, membrane MMPs and other MMPs. Activity of MMPs is regulated at the level of gene transcription, mRNA stability, zymogene proteolitic activation, inhibition of an active enzyme and MMP degradation. Tissue inhibitors of metalloproteinases (TIMPs are main intracellular inhibitors of MMPs. Host cells can be stimulated by tumor cells to produce MMPs by secreted interleukins, interferons, growth factors and an extracellular matrix metalloproteinase inducer (EMMPRIN. MMPs are produced by tumor cells, fibroblasts, macrophages, mast cells, polimorphonuclear neutrophiles (PMNs and endothelial cells (ECs. MMPs affect many stages of tumor development, facilitating its growth through promoting tumor cells proliferation, invasion and migration, new blood vessels formation and blocking tumor cells apoptosis. MMPs can promote tumor development in several ways. ECM degradation results in release of peptide growth factors. Growth factors linked with cell surface or binding proteins can also be liberated by MMPs. MMPs can indirectly regulate integrin signalling or cleave E-cadherins, facilitating cell migration. MMPs support metastasis inducing an epithelial to mesenchymal transition (EMT. MMP also support transendothelial migration. MMPs support angiogenesis by releasing pro-angiogenic factors and degrading ECM to support ECs migration. Cell surface growth factor receptors are also cleaved by MMPs, which results in inhibition of tumor development, so is release of anti-angiogenic factors from ECM. 

  5. Messenger RNA for membrane-type 2 matrix metalloproteinase, MT2-MMP, is expressed in human placenta of first trimester.

    Science.gov (United States)

    Bjørn, S F; Hastrup, N; Larsen, J F; Lund, L R; Pyke, C

    2000-01-01

    An intimately regulated cell surface activation of matrix metalloproteinases (MMPs) is believed to be of critical importance for the control of trophoblast invasion. A histological investigation of the expression and localization of three different MMPs, the membrane-type matrix metalloproteinases 1 and 2 (MT1-MMP, MT2-MMP) and matrix metalloproteinase 2 (MMP-2/gelatinase A) was performed by in situ hybridization on consecutive sections from human placentae of first trimester pregnancies. Cytokeratin immunostaining identified trophoblast cells. Both normal and tubal implantation sites were studied. We observed a high degree of coexpression of MT2-MMP, MT1-MMP and MMP-2 mRNAs in single extravillous cytotrophoblasts that had invaded the endometrium and tubal wall. Furthermore, mRNAs for all three genes were also seen in cytotrophoblasts of cell islands. In contrast to this coexpression pattern, MT2-MMP expression was absent from cell columns and decidual cells, in which signals for MT1-MMP and MMP-2 mRNAs were seen. The present data on the cellular expression of MT2-MMP mRNA in placenta extend our knowledge of the proteolytic events that take place during early pregnancy. The data suggest that MT2-MMP, capable of activating MMP-2 in vitro, is involved in the invasion of extravillous cytotrophoblast, possibly related to the physiological activation of MMP-2. Copyright 2000 Harcourt Publishers Ltd.

  6. Perturbation with intrabodies reveals that calpain cleavage is required for degradation of huntingtin exon 1.

    Directory of Open Access Journals (Sweden)

    Amber L Southwell

    2011-01-01

    Full Text Available Proteolytic processing of mutant huntingtin (mHtt, the protein that causes Huntington's disease (HD, is critical for mHtt toxicity and disease progression. mHtt contains several caspase and calpain cleavage sites that generate N-terminal fragments that are more toxic than full-length mHtt. Further processing is then required for the degradation of these fragments, which in turn, reduces toxicity. This unknown, secondary degradative process represents a promising therapeutic target for HD.We have used intrabodies, intracellularly expressed antibody fragments, to gain insight into the mechanism of mutant huntingtin exon 1 (mHDx-1 clearance. Happ1, an intrabody recognizing the proline-rich region of mHDx-1, reduces the level of soluble mHDx-1 by increasing clearance. While proteasome and macroautophagy inhibitors reduce turnover of mHDx-1, Happ1 is still able to reduce mHDx-1 under these conditions, indicating Happ1-accelerated mHDx-1 clearance does not rely on these processes. In contrast, a calpain inhibitor or an inhibitor of lysosomal pH block Happ1-mediated acceleration of mHDx-1 clearance. These results suggest that mHDx-1 is cleaved by calpain, likely followed by lysosomal degradation and this process regulates the turnover rate of mHDx-1. Sequence analysis identifies amino acid (AA 15 as a potential calpain cleavage site. Calpain cleavage of recombinant mHDx-1 in vitro yields fragments of sizes corresponding to this prediction. Moreover, when the site is blocked by binding of another intrabody, V(L12.3, turnover of soluble mHDx-1 in living cells is blocked.These results indicate that calpain-mediated removal of the 15 N-terminal AAs is required for the degradation of mHDx-1, a finding that may have therapeutic implications.

  7. Evidence of Alternative Cystatin C Signal Sequence Cleavage Which Is Influenced by the A25T Polymorphism.

    Directory of Open Access Journals (Sweden)

    Annie Nguyen

    Full Text Available Cystatin C (Cys C is a small, potent, cysteine protease inhibitor. An Ala25Thr (A25T polymorphism in Cys C has been associated with both macular degeneration and late-onset Alzheimer's disease. Previously, studies have suggested that this polymorphism may compromise the secretion of Cys C. Interestingly, we found that untagged A25T, A25T tagged C-terminally with FLAG, or A25T FLAG followed by green fluorescent protein (GFP, were all secreted as efficiently from immortalized human cells as their wild-type (WT counterparts (e.g., 112%, 100%, and 88% of WT levels from HEK-293T cells, respectively. Supporting these observations, WT and A25T Cys C variants also showed similar intracellular steady state levels. Furthermore, A25T Cys C did not activate the unfolded protein response and followed the same canonical endoplasmic reticulum (ER-Golgi trafficking pathway as WT Cys C. WT Cys C has been shown to undergo signal sequence cleavage between residues Gly26 and Ser27. While the A25T polymorphism did not affect Cys C secretion, we hypothesized that it may alter where the Cys C signal sequence is preferentially cleaved. Under normal conditions, WT and A25T Cys C have the same signal sequence cleavage site after Gly26 (referred to as 'site 2' cleavage. However, in particular circumstances when the residues around site 2 are modified (such as by the presence of an N-terminal FLAG tag immediately after Gly26, or by a Gly26Lys (G26K mutation, A25T has a significantly higher likelihood than WT Cys C of alternative signal sequence cleavage after Ala20 ('site 1' or even earlier in the Cys C sequence. Overall, our results indicate that the A25T polymorphism does not cause a significant reduction in Cys C secretion, but instead predisposes the protein to be cleaved at an alternative signal sequence cleavage site if site 2 is hindered. Additional N-terminal amino acids resulting from alternative signal sequence cleavage may, in turn, affect the protease

  8. Expression of matrix metalloproteinase-2 and metalloproteinase-9 in the skin of dogs with visceral leishmaniasis.

    Science.gov (United States)

    Jacintho, Ana Paula Prudente; Melo, Guilherme D; Machado, Gisele F; Bertolo, Paulo Henrique Leal; Moreira, Pamela Rodrigues Reina; Momo, Claudia; Souza, Thiago A; Vasconcelos, Rosemeri de Oliveira

    2018-06-01

    The skin is the first organ to be infected by the parasite in canine visceral leishmaniasis. The enzyme matrix metalloproteinase (MMP) acts towards degradation of the extracellular matrix (ECM) and modulation of the inflammatory response against many kinds of injuries. The aims of this study were to evaluate the expression of MMP-2 and MMP-9 through immunohistochemistry and zymography on the skin (muzzle, ears, and abdomen) of dogs that were naturally infected by Leishmania spp. and to compare these results with immunodetection of the parasite and with alterations to the dermal ECM. Picrosirius red staining was used to differentiate collagen types I and III in three regions of the skin. The parasite load, intensity of inflammation, and production of MMP-2 (latent) and MMP-9 (active and latent) were higher in the ear and muzzle regions. MMP-9 (active) predominated in the infected group of dogs and its production was significantly different to that of the control group. Macrophages, lymphocytes, and plasma cells predominated in the dermal inflammation and formed granulomas in association with degradation of mature collagen (type I) and with discrete deposition of young collagen (type III). This dermal change was more pronounced in dogs with high parasite load in the skin. Therefore, it was concluded that the greater parasite load and intensity of inflammation in the skin led consequently to increased degradation of mature collagen, caused by increased production of MMPs, particularly active MMP-9, in dogs with visceral leishmaniasis. This host response profile possibly favors systemic dissemination of the parasite.

  9. Matrix metalloproteinase-7 and matrix metalloproteinase-25 in oral tongue squamous cell carcinoma.

    Science.gov (United States)

    Mäkinen, Laura K; Häyry, Valtteri; Hagström, Jaana; Sorsa, Timo; Passador-Santos, Fabricio; Keski-Säntti, Harri; Haukka, Jari; Mäkitie, Antti A; Haglund, Caj; Atula, Timo

    2014-12-01

    Predicting the clinical course of early-stage oral tongue squamous cell carcinoma (SCC) is challenging. As matrix metalloproteinases (MMPs) are enzymes associated with invasion, metastasis, and poor survival in many cancers, we examined MMP-7 and MMP-25 in oral tongue SCC. We used tissue microarray (TMA) technique and immunohistochemistry to study the expression of MMP-7 and MMP-25 in 73 patients with stage I to II oral tongue SCC and compared their immunoexpressions with clinical data. Immunohistochemistry revealed MMP-7 and MMP-25 expression in 90% (n = 63 of 70) and 90% (n = 64 of 71) of the tumors, respectively. MMP-7 protein expression was associated with presence of occult cervical metastases (odds ratio [OR], 3.67; p = .013), increased invasion depth (OR, 4.60; p = .005), and higher tumor grade (OR, 3.30; p = .007). MMP-7 expression was predictive for poor outcome (p = .021). Immunostaining of MMP-25 did not correlate with any clinical parameters. We conclude that MMP-7, but not MMP-25, expression may have prognostic significance in early-stage oral tongue SCC. © 2014 Wiley Periodicals, Inc.

  10. Structure of the Cpf1 endonuclease R-loop complex after target DNA cleavage

    DEFF Research Database (Denmark)

    Stella, Stefano; Alcón, Pablo; Montoya, Guillermo

    2017-01-01

    involved in DNA unwinding to form a CRISPR RNA (crRNA)-DNA hybrid and a displaced DNA strand. The protospacer adjacent motif (PAM) is recognized by the PAM-interacting domain. The loop-lysine helix-loop motif in this domain contains three conserved lysine residues that are inserted in a dentate manner...... and the crRNA-DNA hybrid, avoiding DNA re-annealing. Mutations in key residues reveal a mechanism linking the PAM and DNA nuclease sites. Analysis of the Cpf1 structures proposes a singular working model of RNA-guided DNA cleavage, suggesting new avenues for redesign of Cpf1....

  11. Secondary isotope effects on alpha-cleavage reactions

    International Nuclear Information System (INIS)

    Ingemann, S.; Hammerum, S.

    1980-01-01

    Kinetic deuterium isotope effects on mass spectral reactions have in several instances been utilized to provide structural information and to answer mechanistic questions. Typically, the influence of the deuterium label on the rate of one of a number of competing reactions has been studied. Secondary isotope effects have usually been assumed to be relatively insignificant in comparison with the observed kinetic effects, even though various workers have shown that secondary isotope effects may indeed exert a considerable influence on the rates of competing simple cleavages. Recent studies have provided quantitative data to show that the mere presence of deuterium atoms up to six bonds away may influence the rate of a simple cleavage reaction. In relation to an investigation of rearrangements accompanying simple cleavage reactions, a semi-quantitative measure was needed of the variation of the secondary isotope effect with the number of bonds between the deuterium label and the point of rupture. The influence has therefore been examined of the presence of remote deuterium atoms on a typical simple cleavage reaction, the α-cleavage of aliphatic amines. As a model compound, N-methyldipentylamine was chosen, systematically labelled with deuterium. (author)

  12. Identification of accelerated evolution in the metalloproteinase ...

    African Journals Online (AJOL)

    U

    2016-02-24

    Feb 24, 2016 ... rich (about 194 residues long) domains are aligned separately. Cys- switch sites (PKMCGV) and Zn2+ binding motifs (HEXXHXXGXXH) are marked in the box of black color. Phylogenetic tree and homology construction. Phylogenetic tree of 12 SVMPs sequences was done using. *Corresponding author.

  13. Matrix metalloproteinases in the brain and blood–brain barrier: Versatile breakers and makers

    Science.gov (United States)

    Rempe, Ralf G; Hartz, Anika MS

    2016-01-01

    Matrix metalloproteinases are versatile endopeptidases with many different functions in the body in health and disease. In the brain, matrix metalloproteinases are critical for tissue formation, neuronal network remodeling, and blood–brain barrier integrity. Many reviews have been published on matrix metalloproteinases before, most of which focus on the two best studied matrix metalloproteinases, the gelatinases MMP-2 and MMP-9, and their role in one or two diseases. In this review, we provide a broad overview of the role various matrix metalloproteinases play in brain disorders. We summarize and review current knowledge and understanding of matrix metalloproteinases in the brain and at the blood–brain barrier in neuroinflammation, multiple sclerosis, cerebral aneurysms, stroke, epilepsy, Alzheimer’s disease, Parkinson’s disease, and brain cancer. We discuss the detrimental effects matrix metalloproteinases can have in these conditions, contributing to blood–brain barrier leakage, neuroinflammation, neurotoxicity, demyelination, tumor angiogenesis, and cancer metastasis. We also discuss the beneficial role matrix metalloproteinases can play in neuroprotection and anti-inflammation. Finally, we address matrix metalloproteinases as potential therapeutic targets. Together, in this comprehensive review, we summarize current understanding and knowledge of matrix metalloproteinases in the brain and at the blood–brain barrier in brain disorders. PMID:27323783

  14. Inhibition of Matrix Metalloproteinase Activity Prevents Increases in Myocardial Tumor Necrosis Factor-α

    Science.gov (United States)

    Murray, David B.; Levick, Scott P; Brower, Gregory L.; Janicki, Joseph S.

    2010-01-01

    Aim TNF-α is known to cause adverse myocardial remodeling. While we have previously shown a role for cardiac mast cells in mediating myocardial TNF-α, matrix metalloproteinases (MMP) activation of TNF-α may also be contributory. We sought to determine the relative roles of MMPs and cardiac mast cells in the activation of TNF-α in the hearts of rats subjected to chronic volume overload. Methods Interventions with the broad spectrum MMP inhibitor, GM6001, or the mast cell stabilizer, nedocromil, were performed in the rat aortocaval fistula (ACF) model of volume overload. Results Myocardial TNF-α levels were significantly increased in the ACF. This increase was prevented by MMP inhibition with GM6001 (p ≤ 0.001 vs. ACF). Conversely, myocardial TNF-α levels were increased in the ACF + nedocromil treated fistula groups (p ≤ 0.001 vs. sham). The degradation of interstitial collagen volume fraction seen in the untreated ACF group was prevented in both the GM6001 and nedocromil treated hearts. Significant increases in LV myocardial ET-1 levels also occurred in the ACF group at 3 days post-fistula. Whereas administration of GM6001 significantly attenuated this increase, mast cell stabilization with nedocromil markedly exacerbated the increase, producing ET-1 levels 6.5 fold and 2 fold greater than that in the sham-operated control and ACF group, respectively. Conclusion The efficacy of the MMP inhibitor, GM6001, to prevent increased levels of myocardial TNF-α is indicative of MMP-mediated cleavage of latent extracellular membrane bound TNF-α protein as the primary source of bioactive TNF-α in the myocardium of the volume-overload heart. PMID:20403361

  15. Matrix metalloproteinase-20 mediates dental enamel biomineralization by preventing protein occlusion inside apatite crystals.

    Science.gov (United States)

    Prajapati, Saumya; Tao, Jinhui; Ruan, Qichao; De Yoreo, James J; Moradian-Oldak, Janet

    2016-01-01

    Reconstruction of enamel-like materials is a central topic of research in dentistry and material sciences. The importance of precise proteolytic mechanisms in amelogenesis to form a hard tissue with more than 95% mineral content has already been reported. A mutation in the Matrix Metalloproteinase-20 (MMP-20) gene results in hypomineralized enamel that is thin, disorganized and breaks from the underlying dentin. We hypothesized that the absence of MMP-20 during amelogenesis results in the occlusion of amelogenin in the enamel hydroxyapatite crystals. We used spectroscopy and electron microscopy techniques to qualitatively and quantitatively analyze occluded proteins within the isolated enamel crystals from MMP-20 null and Wild type (WT) mice. Our results showed that the isolated enamel crystals of MMP-20 null mice had more organic macromolecules occluded inside them than enamel crystals from the WT. The crystal lattice arrangements of MMP-20 null enamel crystals analyzed by High Resolution Transmission Electron Microscopy (HRTEM) were found to be significantly different from those of the WT. Raman studies indicated that the crystallinity of the MMP-20 null enamel crystals was lower than that of the WT. In conclusion, we present a novel functional mechanism of MMP-20, specifically prevention of unwanted organic material entrapped in the forming enamel crystals, which occurs as the result of precise amelogenin cleavage. MMP-20 action guides the growth morphology of the forming hydroxyapatite crystals and enhances their crystallinity. Elucidating such molecular mechanisms can be applied in the design of novel biomaterials for future clinical applications in dental restoration or repair. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. A new cultural cleavage in post-modern society

    Directory of Open Access Journals (Sweden)

    Jan-Erik Lane

    2007-09-01

    Full Text Available The attitudes towards gender and homosexuality tend to be linked at the micro level (individuals, which explains the political saliency of this newly emerging cleavage. At the macro level (country, the main finding is that the value orientations towards gender and homosexuality are strongly embedded in the basic cultural or civilisation differences among countries. As developing countries modernise and enter post-modernity, they will also experience the gender cleavage, especially when they adhere to an individualistic culture. Cultural cleavages in the post-modern society, whether in rich or developing countries, can only be properly researched by the survey method. It opens up a large area for both micro and macro analyses in the social sciences.

  17. New Insight into the Cleavage Reaction of Nostoc sp. Strain PCC 7120 Carotenoid Cleavage Dioxygenase in Natural and Nonnatural Carotenoids

    Science.gov (United States)

    Heo, Jinsol; Kim, Se Hyeuk

    2013-01-01

    Carotenoid cleavage dioxygenases (CCDs) are enzymes that catalyze the oxidative cleavage of carotenoids at a specific double bond to generate apocarotenoids. In this study, we investigated the activity and substrate preferences of NSC3, a CCD of Nostoc sp. strain PCC 7120, in vivo and in vitro using natural and nonnatural carotenoid structures. NSC3 cleaved β-apo-8′-carotenal at 3 positions, C-13C-14, C-15C-15′, and C-13′C-14′, revealing a unique cleavage pattern. NSC3 cleaves the natural structure of carotenoids 4,4′-diaponeurosporene, 4,4′-diaponeurosporen-4′-al, 4,4′-diaponeurosporen-4′-oic acid, 4,4′-diapotorulene, and 4,4′-diapotorulen-4′-al to generate novel cleavage products (apo-14′-diaponeurosporenal, apo-13′-diaponeurosporenal, apo-10′-diaponeurosporenal, apo-14′-diapotorulenal, and apo-10′-diapotorulenal, respectively). The study of carotenoids with natural or nonnatural structures produced by using synthetic modules could provide information valuable for understanding the cleavage reactions or substrate preferences of other CCDs in vivo and in vitro. PMID:23524669

  18. Identification of Rbd2 as a candidate protease for sterol regulatory element binding protein (SREBP) cleavage in fission yeast

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jinsil; Ha, Hye-Jeong [Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Kim, Sujin [Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Department of Functional Genomics, University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon 34113 (Korea, Republic of); Choi, Ah-Reum [Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Lee, Sook-Jeong [Department of New Drug Discovery and Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134 (Korea, Republic of); Hoe, Kwang-Lae, E-mail: kwanghoe@cnu.ac.kr [Department of New Drug Discovery and Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134 (Korea, Republic of); Kim, Dong-Uk, E-mail: kimdongu@kribb.re.kr [Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of)

    2015-12-25

    Lipid homeostasis in mammalian cells is regulated by sterol regulatory element-binding protein (SREBP) transcription factors that are activated through sequential cleavage by Golgi Site-1 and Site-2 proteases. Fission yeast SREBP, Sre1, engages a different mechanism involving the Golgi Dsc E3 ligase complex, but it is not clearly understood exactly how Sre1 is proteolytically cleaved and activated. In this study, we screened the Schizosaccharomyces pombe non-essential haploid deletion collection to identify missing components of the Sre1 cleavage machinery. Our screen identified an additional component of the SREBP pathway required for Sre1 proteolysis named rhomboid protein 2 (Rbd2). We show that an rbd2 deletion mutant fails to grow under hypoxic and hypoxia-mimetic conditions due to lack of Sre1 activity and that this growth phenotype is rescued by Sre1N, a cleaved active form of Sre1. We found that the growth inhibition phenotype under low oxygen conditions is specific to the strain with deletion of rbd2, not any other fission yeast rhomboid-encoding genes. Our study also identified conserved residues of Rbd2 that are required for Sre1 proteolytic cleavage. All together, our results suggest that Rbd2 is a functional SREBP protease with conserved residues required for Sre1 cleavage and provide an important piece of the puzzle to understand the mechanisms for Sre1 activation and the regulation of various biological and pathological processes involving SREBPs. - Highlights: • An rbd2-deleted yeast strain shows defects in growth in response to low oxygen levels. • rbd2-deficient cells fail to generate cleaved Sre1 (Sre1N) under hypoxic conditions. • Expression of Sre1N rescues the rbd2 deletion mutant growth phenotype. • Rbd2 contains conserved residues potentially critical for catalytic activity. • Mutation of the conserved Rbd2 catalytic residues leads to defects in Sre1 cleavage.

  19. Collagenolytic Matrix Metalloproteinase Structure-Function Relationships: Insights From Molecular Dynamics Studies.

    Science.gov (United States)

    Karabencheva-Christova, Tatyana G; Christov, Christo Z; Fields, Gregg B

    2017-01-01

    Several members of the zinc-dependent matrix metalloproteinase (MMP) family catalyze collagen degradation. Experimental data reveal a collaboration between different MMP domains in order to achieve efficient collagenolysis. Molecular dynamics (MD) simulations have been utilized to provide atomistic details of the collagenolytic process. The triple-helical structure of collagen exhibits local regions of flexibility, with modulation of interchain salt bridges and water bridges contributing to accessibility of individual chains by the enzyme. In turn, the hemopexin-like (HPX) domain of the MMP initially binds the triple helix and facilitates the presentation of individual strands to active site in the catalytic (CAT) domain. Extensive positive and negative correlated motions are observed between the CAT and HPX domains when collagen is bound. Ultimately, the MD simulation studies have complemented structural (NMR spectroscopy, X-ray crystallography) and kinetic analyses to provide a more detailed mechanistic view of MMP-catalyzed collagenolysis. © 2017 Elsevier Inc. All rights reserved.

  20. Sensitive and fast mutation detection by solid phase chemical cleavage

    DEFF Research Database (Denmark)

    Hansen, Lise Lotte; Justesen, Just; Kruse, Torben A

    1996-01-01

    We have developed a solid phase chemical cleavage method (SpCCM) for screening large DNA fragments for mutations. All reactions can be carried out in microtiterwells from the first amplification of the patient (or test) DNA through the search for mutations. The reaction time is significantly...... reduced compared to the conventional chemical cleavage method (CCM), and even by using a uniformly labelled probe, the exact position and nature of the mutation can be revealed. The SpCCM is suitable for automatization using a workstation to carry out the reactions and a fluorescent detection-based DNA...

  1. Matrix metalloproteinases during and outside of migraine attacks without aura

    DEFF Research Database (Denmark)

    Ashina, M.; Tvedskov, J.F.; Thiesen, Kerstin Lipka

    2010-01-01

    Ashina M, Tvedskov JF, Lipka K, Bilello J, Penkowa M & Olesen J. Matrix metalloproteinases during and outside of migraine attacks without aura. Cephalalgia 2009. London. ISSN 0333-1024To test the hypothesis that permeability of the blood-brain barrier (BBB) is altered during migraine attack due...... to enhanced activation of matrix metalloproteinases (MMPs), we investigated MMP-3, MMP-9 and tissue inhibitor of metalloproteases (TIMP)-1 in the external jugular vein during and outside of migraine attacks in 21 patients with migraine without aura. In addition, we measured plasma levels of several other...... of MMP-3 in the external jugular (P = 0.002) and cubital (P = 0.008) vein during attacks compared with outside of attacks. We found no correlation of ictal or interictal MMP-3, MMP-9 and TIMP-1 to migraine duration and frequency analysed in 21 patients (P > 0.05). There was no difference between ictal...

  2. Matrix metalloproteinases in acute coronary syndromes: current perspectives.

    Science.gov (United States)

    Kampoli, Anna-Maria; Tousoulis, Dimitris; Papageorgiou, Nikolaos; Antoniades, Charalambos; Androulakis, Emmanuel; Tsiamis, Eleftherios; Latsios, George; Stefanadis, Christodoulos

    2012-01-01

    Matrix metalloproteinases (MMPs) are a family of zinc metallo-endopeptidases secreted by cells and are responsible for much of the turnover of matrix components. Several studies have shown that MMPs are involved in all stages of the atherosclerotic process, from the initial lesion to plaque rupture. Recent evidence suggests that MMP activity may facilitate atherosclerosis, plaque destabilization, and platelet aggregation. In the heart, matrix metalloproteinases participate in vascular remodeling, plaque instability, and ventricular remodelling after cardiac injury. The aim of the present article is to review the structure, function, regulation of MMPs and to discuss their potential role in the pathogenesis of acute coronary syndromes, as well as their contribution and usefullness in the setting of the disease.

  3. Two Divalent Metal Ions and Conformational Changes Play Roles in the Hammerhead Ribozyme Cleavage Reaction

    Science.gov (United States)

    Mir, Aamir; Chen, Ji; Robinson, Kyle; Lendy, Emma; Goodman, Jaclyn; Neau, David; Golden, Barbara L.

    2016-01-01

    The hammerhead ribozyme is a self-cleaving RNA broadly dispersed across all kingdoms of life. Although it was the first of the small, nucleolytic ribozymes discovered, the mechanism by which it catalyzes its reaction remains elusive. The nucleobase of G12 is well positioned to be a general base, but it is unclear if or how this guanine base becomes activated for proton transfer. Metal ions have been implicated in the chemical mechanism, but no interactions between divalent metal ions and the cleavage site have been observed crystallographically. To better understand how this ribozyme functions, we have solved crystal structures of wild-type and G12A mutant ribozymes. We observe a pH-dependent conformational change centered around G12, consistent with this nucleotide becoming deprotonated. Crystallographic and kinetic analysis of the G12A mutant reveals a Zn2+ specificity switch suggesting a direct interaction between a divalent metal ion and the purine at position 12. The metal ion specificity switch and the pH–rate profile of the G12A mutant suggest that the minor imino tautomer of A12 serves as the general base in the mutant ribozyme. We propose a model in which the hammerhead ribozyme rearranges prior to the cleavage reaction, positioning two divalent metal ions in the process. The first metal ion, positioned near G12, becomes directly coordinated to the O6 keto oxygen, to lower the pKa of the general base and organize the active site. The second metal ion, positioned near G10.1, bridges the N7 of G10.1 and the scissile phosphate and may participate directly in the cleavage reaction. PMID:26398724

  4. Abnormal early cleavage events predict early embryo demise: sperm oxidative stress and early abnormal cleavage.

    Science.gov (United States)

    Burruel, Victoria; Klooster, Katie; Barker, Christopher M; Pera, Renee Reijo; Meyers, Stuart

    2014-10-13

    Human embryos resulting from abnormal early cleavage can result in aneuploidy and failure to develop normally to the blastocyst stage. The nature of paternal influence on early embryo development has not been directly demonstrated although many studies have suggested effects from spermatozoal chromatin packaging, DNA damage, centriolar and mitotic spindle integrity, and plasma membrane integrity. The goal of this study was to determine whether early developmental events were affected by oxidative damage to the fertilizing sperm. Survival analysis was used to compare patterns of blastocyst formation based on P2 duration. Kaplan-Meier survival curves demonstrate that relatively few embryos with short (P2 times reached blastocysts, and the two curves diverged beginning on day 4, with nearly all of the embryos with longer P2 times reaching blastocysts by day 6 (p < .01). We determined that duration of the 2nd to 3rd mitoses were sensitive periods in the presence of spermatozoal oxidative stress. Embryos that displayed either too long or too short cytokineses demonstrated an increased failure to reach blastocyst stage and therefore survive for further development. Although paternal-derived gene expression occurs later in development, this study suggests a specific role in early mitosis that is highly influenced by paternal factors.

  5. Human trophoblast survival at low oxygen concentrations requires metalloproteinase-mediated shedding of heparin-binding EGF-like growth factor.

    Science.gov (United States)

    Armant, D Randall; Kilburn, Brian A; Petkova, Anelia; Edwin, Samuel S; Duniec-Dmuchowski, Zophia M; Edwards, Holly J; Romero, Roberto; Leach, Richard E

    2006-02-01

    Heparin-binding EGF-like growth factor (HBEGF), which is expressed in the placenta during normal pregnancy, is down regulated in pre-eclampsia, a human pregnancy disorder associated with poor trophoblast differentiation and survival. This growth factor protects against apoptosis during stress, suggesting a role in trophoblast survival in the relatively low O(2) ( approximately 2%) environment of the first trimester conceptus. Using a well-characterized human first trimester cytotrophoblast cell line, we found that a 4-hour exposure to 2% O(2) upregulates HBEGF synthesis and secretion independently of an increase in its mRNA. Five other expressed members of the EGF family are largely unaffected. At 2% O(2), signaling via HER1 or HER4, known HBEGF receptors, is required for both HBEGF upregulation and protection against apoptosis. This positive-feedback loop is dependent on metalloproteinase-mediated cleavage and shedding of the HBEGF ectodomain. The restoration of trophoblast survival by the addition of soluble HBEGF in cultures exposed to low O(2) and metalloproteinase inhibitor suggests that the effects of HBEGF are mediated by autocrine/paracrine, rather than juxtacrine, signaling. Our results provide evidence that a post-transcriptional mechanism induced in trophoblasts by low O(2) rapidly amplifies HBEGF signaling to inhibit apoptosis. These findings have a high clinical significance, as the downregulation of HBEGF in pre-eclampsia is likely to be a contributing factor leading to the demise of trophoblasts.

  6. Beneficial Regulation of Matrix Metalloproteinases for Skin Health

    Directory of Open Access Journals (Sweden)

    Neena Philips

    2011-01-01

    Full Text Available Matrix metalloproteinases (MMPs are essential to the remodeling of the extracellular matrix. While their upregulation facilitates aging and cancer, they are essential to epidermal differentiation and the prevention of wound scars. The pharmaceutical industry is active in identifying products that inhibit MMPs to prevent or treat aging and cancer and products that stimulate MMPs to prevent epidermal hyperproliferative diseases and wound scars.

  7. Periodontal Disease, Matrix Metalloproteinases and Chemically Modified Tetracyclines

    OpenAIRE

    Steinsvoll, Svein

    2011-01-01

    Matrix metalloproteinases (MMPs) are crucial in the degradation of the main components in the extracellular matrix and thereby play important roles in cell migration, wound healing and tissue remodelling. MMPs have pathogenic roles in arthritis, periodontitis, hepatitis, glomerulonephritis, atherosclerosis and cancer cell invasion. MMPs are activators of pro-inflammatory mediators that occur in latent forms, such as interleukin (IL)-1β, membrane-bound tumour necrosis factor (TNF) and dif...

  8. Matrix Metalloproteinases as Therapeutic Targets for Idiopathic Pulmonary Fibrosis

    OpenAIRE

    Craig, Vanessa J.; Zhang, Li; Hagood, James S.; Owen, Caroline A.

    2015-01-01

    Idiopathic pulmonary fibrosis (IPF) is a restrictive lung disease that is associated with high morbidity and mortality. Current medical therapies are not fully effective at limiting mortality in patients with IPF, and new therapies are urgently needed. Matrix metalloproteinases (MMPs) are proteinases that, together, can degrade all components of the extracellular matrix and numerous nonmatrix proteins. MMPs and their inhibitors, tissue inhibitors of MMPs (TIMPs), have been implicated in the p...

  9. Matrix metalloproteinases in stem cell regulation and cancer

    OpenAIRE

    Kessenbrock, K; Wang, CY; Wang, CY; Werb, Z

    2014-01-01

    © 2015. Since Gross and Lapiere firstly discovered matrix metalloproteinases (MMPs) as important collagenolytic enzymes during amphibian tadpole morphogenesis in 1962, this intriguing family of extracellular proteinases has been implicated in various processes of developmental biology. However, the pathogenic roles of MMPs in human diseases such as cancer have also garnered widespread attention. The most straightforward explanation for their role in cancer is that MMPs, through extracellular ...

  10. Correlation between expression of extracellular matrix metalloproteinase inducer and matrix metalloproteinase-2 and cervical lymph node metastasis of nasopharyngeal carcinoma.

    Science.gov (United States)

    Huang, Tian; Chen, Mao-Huai; Wu, Ming-Yao; Wu, Xian-Ying

    2013-03-01

    We evaluated the expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase-2 (MMP-2) in nasopharyngeal carcinoma (NPC) and studied their relationship with cervical lymph node metastasis. Immunohistochemical staining was used to detect the expression of EMMPRIN and MMP-2 in specimens from patients with chronic nasopharyngitis (CN), nonmetastastic NPC (NM-NPC), and lymph node-metastatic NPC (LNM-NPC). The rates of positive EMMPRIN expression in CN, NM-NPC, and LNM-NPC were 13.3%, 30.0%, and 66.7%, respectively. Significant differences were found between the rates in CN and LNM-NPC (p correlated (rs = 0.466; p <0.01). Nasopharyngeal carcinoma cells may attain enhanced metastastic capability through the expression of MMP-2 induced by EMMPRIN.

  11. Matrix metalloproteinase 2 and membrane type 1 matrix metalloproteinase co-regulate axonal outgrowth of mouse retinal ganglion cells

    DEFF Research Database (Denmark)

    Gaublomme, Djoere; Buyens, Tom; De Groef, Lies

    2014-01-01

    regenerative therapies, an improved understanding of axonal outgrowth and the various molecules influencing it, is highly needed. Matrix metalloproteinases (MMPs) constitute a family of zinc-dependent proteases that were sporadically reported to influence axon outgrowth. Using an ex vivo retinal explant model......, but not MMP-9, are involved in this process. Furthermore, administration of a novel antibody to MT1-MMP that selectively blocks pro-MMP-2 activation revealed a functional co-involvement of these proteinases in determining RGC axon outgrowth. Subsequent immunostainings showed expression of both MMP-2 and MT1...... nervous system is lacking in adult mammals, thereby impeding recovery from injury to the nervous system. Matrix metalloproteinases (MMPs) constitute a family of zinc-dependent proteases that were sporadically reported to influence axon outgrowth. Inhibition of specific MMPs reduced neurite outgrowth from...

  12. Single-stranded DNA cleavage by divergent CRISPR-Cas9 enzymes

    Science.gov (United States)

    Ma, Enbo; Harrington, Lucas B.; O’Connell, Mitchell R.; Zhou, Kaihong; Doudna, Jennifer A.

    2015-01-01

    Summary Double-stranded DNA (dsDNA) cleavage by Cas9 is a hallmark of type II CRISPR-Cas immune systems. Cas9–guide RNA complexes recognize 20-base-pair sequences in DNA and generate a site-specific double-strand break, a robust activity harnessed for genome editing. DNA recognition by all studied Cas9 enzymes requires a protospacer adjacent motif (PAM) next to the target site. We show that Cas9 enzymes from evolutionarily divergent bacteria can recognize and cleave single-stranded DNA (ssDNA) by an RNA-guided, PAM-independent recognition mechanism. Comparative analysis shows that in contrast to the type II-A S. pyogenes Cas9 that is widely used for genome engineering, the smaller type II-C Cas9 proteins have limited dsDNA binding and unwinding activity and promiscuous guide-RNA specificity. These results indicate that inefficiency of type II-C Cas9 enzymes for genome editing results from a limited ability to cleave dsDNA, and suggest that ssDNA cleavage was an ancestral function of the Cas9 enzyme family. PMID:26545076

  13. The Conformational Dynamics of Cas9 Governing DNA Cleavage Are Revealed by Single-Molecule FRET.

    Science.gov (United States)

    Yang, Mengyi; Peng, Sijia; Sun, Ruirui; Lin, Jingdi; Wang, Nan; Chen, Chunlai

    2018-01-09

    Off-target binding and cleavage by Cas9 pose major challenges in its application. How the conformational dynamics of Cas9 govern its nuclease activity under on- and off-target conditions remains largely unknown. Here, using intra-molecular single-molecule fluorescence resonance energy transfer measurements, we revealed that Cas9 in apo, sgRNA-bound, and dsDNA/sgRNA-bound forms spontaneously transits among three major conformational states, mainly reflecting significant conformational mobility of the catalytic HNH domain. We also uncovered surprising long-range allosteric communication between the HNH domain and the RNA/DNA heteroduplex at the PAM-distal end to ensure correct positioning of the catalytic site, which demonstrated that a unique proofreading mechanism served as the last checkpoint before DNA cleavage. Several Cas9 residues were likely to mediate the allosteric communication and proofreading step. Modulating interactions between Cas9 and heteroduplex at the PAM-distal end by introducing mutations on these sites provides an alternative route to improve and optimize the CRISPR/Cas9 toolbox. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  14. Impaired Cleavage of Preproinsulin Signal Peptide Linked to Autosomal-Dominant Diabetes

    Science.gov (United States)

    Liu, Ming; Lara-Lemus, Roberto; Shan, Shu-ou; Wright, Jordan; Haataja, Leena; Barbetti, Fabrizio; Guo, Huan; Larkin, Dennis; Arvan, Peter

    2012-01-01

    Recently, missense mutations upstream of preproinsulin’s signal peptide (SP) cleavage site were reported to cause mutant INS gene-induced diabetes of youth (MIDY). Our objective was to understand the molecular pathogenesis using metabolic labeling and assays of proinsulin export and insulin and C-peptide production to examine the earliest events of insulin biosynthesis, highlighting molecular mechanisms underlying β-cell failure plus a novel strategy that might ameliorate the MIDY syndrome. We find that whereas preproinsulin-A(SP23)S is efficiently cleaved, producing authentic proinsulin and insulin, preproinsulin-A(SP24)D is inefficiently cleaved at an improper site, producing two subpopulations of molecules. Both show impaired oxidative folding and are retained in the endoplasmic reticulum (ER). Preproinsulin-A(SP24)D also blocks ER exit of coexpressed wild-type proinsulin, accounting for its dominant-negative behavior. Upon increased expression of ER–oxidoreductin-1, preproinsulin-A(SP24)D remains blocked but oxidative folding of wild-type proinsulin improves, accelerating its ER export and increasing wild-type insulin production. We conclude that the efficiency of SP cleavage is linked to the oxidation of (pre)proinsulin. In turn, impaired (pre)proinsulin oxidation affects ER export of the mutant as well as that of coexpressed wild-type proinsulin. Improving oxidative folding of wild-type proinsulin may provide a feasible way to rescue insulin production in patients with MIDY. PMID:22357960

  15. TRAIL-induced cleavage and inactivation of SPAK sensitizes cells to apoptosis

    International Nuclear Information System (INIS)

    Polek, Tara C.; Talpaz, Moshe; Spivak-Kroizman, Taly R.

    2006-01-01

    Ste20-related proline-alanine-rich kinase (SPAK) has been linked to various cellular processes, including proliferation, differentiation, and ion transport regulation. Recently, we showed that SPAK mediates signaling by the TNF receptor, RELT. The presence of a caspase cleavage site in SPAK prompted us to study its involvement in apoptotic signaling induced by another TNF member, TRAIL. We show that TRAIL stimulated caspase 3-like proteases that cleaved SPAK at two distinct sites. Cleavage had little effect on the activity of SPAK but removed its substrate-binding domain. In addition, TRAIL reduced the activity of SPAK in HeLa cells in a caspase-independent manner. Thus, TRAIL inhibited SPAK by two mechanisms: activation of caspases, which removed its substrate-binding domain, and caspase-independent down-regulation of SPAK activity. Furthermore, reducing the amount of SPAK by siRNA increased the sensitivity of HeLa cells to TRAIL-induced apoptosis. Thus, TRAIL down-regulation of SPAK is an important event that enhances its apoptotic effects

  16. The presence of promatrix metalloproteinase-3 and its relation with different categories of coal workers' pneumoconiosis

    Directory of Open Access Journals (Sweden)

    Remzi Altin

    2004-01-01

    Full Text Available Extracellular matrix formation (ECM and remodeling are critical events related to the pathogenesis of pulmonary fibrosis. Matrix metalloproteinases play an essential role in degrading and remodeling the ECM. In this study, we tried to show the presence and correlation of promatrix metalloproteinase-3 (proMMP-3 (the inactive form of metalloproteinase-3 levels in coal workers' pneumoconiosis (CWP with different categories.

  17. DNA Cleavage Activity of Diazonium Salts: Chemical Nucleases

    OpenAIRE

    KIZIL, Murat

    2014-01-01

    4-Fenoldiazonium tetrafluoroborate and 4-benzoicaciddiazonium tetrafluoroborate was prepared and was shown to be an effective DNA cleavage agent in the presence of the 1-electron donor copper(II) chloride. Its mechanism involves the generation of the aryl radical cleaving DNA by hydrogen atom abstraction from deoxyribose sugar.

  18. Fe-Catalyzed Oxidative Cleavage of Unsaturated Fatty Acids

    NARCIS (Netherlands)

    Spannring, P.

    2013-01-01

    The oxidative cleavage of unsaturated fatty acids into aldehydes or carboxylic acids gives access to valuable products. The products can be used as chemical building blocks, as emulsifiers or in the paint or polymer industry. Ozonolysis is applied industrially to cleave the fatty acid oleic acid

  19. Kinetics of phycocyanobilin cleavage from C-phycocyanin by methanolysis

    DEFF Research Database (Denmark)

    Malwade, Chandrakant Ramkrishna; Roda Serrat, Maria Cinta; Christensen, Knud Villy

    2016-01-01

    Phycocyanobilin (PCB) is an important linear tetrapyrrolic molecule for food as well as pharmaceutical industry. It is obtained from blue-green algae, where it is attached covalently to phycobiliproteins (C-PC and APC) present in the light harvesting complexes. In this work, cleavage of PCB from...

  20. Cell-surface acceleration of urokinase-catalyzed receptor cleavage

    DEFF Research Database (Denmark)

    Høyer-Hansen, G; Ploug, M; Behrendt, N

    1997-01-01

    by a prior incubation of the cells with uPA inactivated by diisopropyl fluorophosphate, demonstrating a requirement for specific receptor binding of the active uPA to obtain the high-efficiency cleavage of cell-bound uPAR. Furthermore, amino-terminal sequence analysis revealed that uPAR(2+3), purified from U...

  1. Modulation of Matrix Metalloproteinase 14, Tissue Inhibitor of Metalloproteinase 3, Tissue Inhibitor of Metalloproteinase 4, and Inducible Nitric Oxide Synthase in the Development of Periapical Lesions.

    Science.gov (United States)

    Cassanta, Lorena Teodoro de Castro; Rodrigues, Virmondes; Violatti-Filho, Jose Roberto; Teixeira Neto, Benedito Alves; Tavares, Vinícius Marques; Bernal, Eduarda Castelo Branco Araujo; Souza, Danila Malheiros; Araujo, Marcelo Sivieri; de Lima Pereira, Sanivia Aparecida; Rodrigues, Denise Bertulucci Rocha

    2017-07-01

    Periapical cysts and granulomas are chronic lesions caused by an inflammatory immune response against microbial challenge in the root canal. Different cell types, cytokines, and molecules have been associated with periapical lesion formation and expansion. Therefore, because of the chronic inflammatory state of these lesions, the aim of this study was to evaluate the in situ expression of matrix metalloproteinase (MMP)-14 and -19, tissue inhibitor of metalloproteinase (TIMP)-3 and -4, CD68, and inducible nitric oxide synthase (iNOS) in periapical cysts and granulomas. Sixteen cases of periapical cysts and 15 cases of periapical granulomas were analyzed. Ten normal dental pulps were used as the negative control. Immunohistochemistry was performed with anti-MMP-19, anti-MMP-14, anti-TIMP-3, anti-TIMP-4, anti-iNOS, and anti-CD68 antibodies. The expression of TIMP-3, TIMP-4, iNOS, and CD68 was significantly higher in both the cyst and granuloma groups than in the control group. TIMP-4 was also significantly higher in cases of chronic apical abscess. There was also a significant difference in the expression of MMP-14 between the cyst and control groups. However, there were no differences in the expression of MMP-19 between the 3 groups. Our data suggest that the expression of MMP-14, TIMP-3, and TIMP-4 is associated with the development of periapical lesions. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  2. Developmental roles of the BMP1/TLD metalloproteinases.

    Science.gov (United States)

    Ge, Gaoxiang; Greenspan, Daniel S

    2006-03-01

    The astacin family (M12A) of the metzincin subclan MA(M) of metalloproteinases has been detected in developing and mature individuals of species that range from hydra to humans. Functions of this family of metalloproteinase vary from digestive degradation of polypeptides, to biosynthetic processing of extracellular proteins, to activation of growth factors. This review will focus on a small subgroup of the astacin family; the bone morphogenetic protein 1 (BMP1)/Tolloid (TLD)-like metalloproteinases. In vertebrates, the BMP1/TLD-like metalloproteinases play key roles in regulating formation of the extracellular matrix (ECM) via biosynthetic processing of various precursor proteins into mature functional enzymes, structural proteins, and proteins involved in initiating mineralization of the ECM of hard tissues. Roles in ECM formation include: processing of the C-propeptides of procollagens types I-III, to yield the major fibrous components of vertebrate ECM; proteolytic activation of the enzyme lysyl oxidase, necessary to formation of covalent cross-links in collagen and elastic fibers; processing of NH2-terminal globular domains and C-propeptides of types V and XI procollagen chains to yield monomers that are incorporated into and control the diameters of collagen type I and II fibrils, respectively; processing of precursors for laminin 5 and collagen type VII, both of which are involved in securing epidermis to underlying dermis; and maturation of small leucine-rich proteoglycans. The BMP1/TLD-related metalloproteinases are also capable of activating the vertebrate transforming growth factor-beta (TGF-beta)-like "chalones" growth differentiation factor 8 (GDF8, also known as myostatin), and GDF11 (also known as BMP11), involved in negative feedback inhibition of muscle and neural tissue growth, respectively; by freeing them from noncovalent latent complexes with their cleaved prodomains. BMP1/TLD-like proteinases also liberate the vertebrate TGF

  3. Matrix metalloproteinase 2 and tissue inhibitor of matrix metalloproteinases 2 in the diagnosis of colorectal adenoma and cancer patients

    Directory of Open Access Journals (Sweden)

    Magdalena Groblewska

    2010-04-01

    Full Text Available The aim of the study was to assess the importance of the measurement of matrix metalloproteinase 2 (MMP-2and tissue inhibitor of matrix metalloproteinases 2 (TIMP-2 in patients with colorectal cancer (CRC in relation to clinicopathologicalfeatures of tumor and patients' survival. Additionally, we determined serum MMP-2 and TIMP-2 in colorectaladenoma (CA patients and healthy controls and compared them with tumor markers, CEA and CA 19-9. The serum levelsof MMP-2 and TIMP-2 in 91 CRC patients, 28 CA subjects and 91 healthy controls were determined by ELISA method, butconcentrations of CEA and CA 19-9 using MEIA method. Nonparametric statistical analyses were used. Serum levels ofMMP-2 and TIMP-2 were significantly lower in CRC patients than in healthy subjects and decreased with tumor stage.Additionally, MMP-2 concentrations were significantly lower in patients with CRC than in CA group. Diagnostic sensitivityof TIMP-2 (59% was the highest among biomarkers tested and increased in combined use with CEA (79%. Moreover,the area under ROC curve (AUC of TIMP-2 was larger than AUC of MMP-2 in differentiation between CRC and healthysubjects, but lower than AUC of matrix metalloproteinase 2 in differentiation between colorectal cancer and adenoma. Ourfindings suggest clinical usefulness of TIMP-2 as a biomarker in the diagnosis of CRC, especially in combination with CEA.However, further investigation is necessary.

  4. Matrix metalloproteinase 2 and tissue inhibitor of matrix metalloproteinases 2 in the diagnosis of colorectal adenoma and cancer patients.

    Directory of Open Access Journals (Sweden)

    Barbara Mroczko

    2011-04-01

    Full Text Available The aim of the study was to assess the importance of the measurement of matrix metalloproteinase 2 (MMP-2 and tissue inhibitor of matrix metalloproteinases 2 (TIMP-2 in patients with colorectal cancer (CRC in relation to clinicopathological features of tumor and patients' survival. Additionally, we determined serum MMP-2 and TIMP-2 in colorectal adenoma (CA patients and healthy controls and compared them with tumor markers, CEA and CA 19-9. The serum levels of MMP-2 and TIMP-2 in 91 CRC patients, 28 CA subjects and 91 healthy controls were determined by ELISA method, but concentrations of CEA and CA 19-9 using MEIA method. Nonparametric statistical analyses were used. Serum levels of MMP-2 and TIMP-2 were significantly lower in CRC patients than in healthy subjects and decreased with tumor stage. Additionally, MMP-2 concentrations were significantly lower in patients with CRC than in CA group. Diagnostic sensitivity of TIMP-2 (59% was the highest among biomarkers tested and increased in combined use with CEA (79%. Moreover, the area under ROC curve (AUC of TIMP-2 was larger than AUC of MMP-2 in differentiation between CRC and healthy subjects, but lower than AUC of matrix metalloproteinase 2 in differentiation between colorectal cancer and adenoma. Our findings suggest clinical usefulness of TIMP-2 as a biomarker in the diagnosis of CRC, especially in combination with CEA. However, further investigation is necessary.

  5. High-resolution characterization of sequence signatures due to non-random cleavage of cell-free DNA.

    Science.gov (United States)

    Chandrananda, Dineika; Thorne, Natalie P; Bahlo, Melanie

    2015-06-17

    High-throughput sequencing of cell-free DNA fragments found in human plasma has been used to non-invasively detect fetal aneuploidy, monitor organ transplants and investigate tumor DNA. However, many biological properties of this extracellular genetic material remain unknown. Research that further characterizes circulating DNA could substantially increase its diagnostic value by allowing the application of more sophisticated bioinformatics tools that lead to an improved signal to noise ratio in the sequencing data. In this study, we investigate various features of cell-free DNA in plasma using deep-sequencing data from two pregnant women (>70X, >50X) and compare them with matched cellular DNA. We utilize a descriptive approach to examine how the biological cleavage of cell-free DNA affects different sequence signatures such as fragment lengths, sequence motifs at fragment ends and the distribution of cleavage sites along the genome. We show that the size distributions of these cell-free DNA molecules are dependent on their autosomal and mitochondrial origin as well as the genomic location within chromosomes. DNA mapping to particular microsatellites and alpha repeat elements display unique size signatures. We show how cell-free fragments occur in clusters along the genome, localizing to nucleosomal arrays and are preferentially cleaved at linker regions by correlating the mapping locations of these fragments with ENCODE annotation of chromatin organization. Our work further demonstrates that cell-free autosomal DNA cleavage is sequence dependent. The region spanning up to 10 positions on either side of the DNA cleavage site show a consistent pattern of preference for specific nucleotides. This sequence motif is present in cleavage sites localized to nucleosomal cores and linker regions but is absent in nucleosome-free mitochondrial DNA. These background signals in cell-free DNA sequencing data stem from the non-random biological cleavage of these fragments. This

  6. Cleavage of influenza RNA by using a human PUF-based artificial RNA-binding protein–staphylococcal nuclease hybrid

    International Nuclear Information System (INIS)

    Mori, Tomoaki; Nakamura, Kento; Masaoka, Keisuke; Fujita, Yusuke; Morisada, Ryosuke; Mori, Koichi; Tobimatsu, Takamasa; Sera, Takashi

    2016-01-01

    Various viruses infect animals and humans and cause a variety of diseases, including cancer. However, effective methodologies to prevent virus infection have not yet been established. Therefore, development of technologies to inactivate viruses is highly desired. We have already demonstrated that cleavage of a DNA virus genome was effective to prevent its replication. Here, we expanded this methodology to RNA viruses. In the present study, we used staphylococcal nuclease (SNase) instead of the PIN domain (PilT N-terminus) of human SMG6 as an RNA-cleavage domain and fused the SNase to a human Pumilio/fem-3 binding factor (PUF)-based artificial RNA-binding protein to construct an artificial RNA restriction enzyme with enhanced RNA-cleavage rates for influenzavirus. The resulting SNase-fusion nuclease cleaved influenza RNA at rates 120-fold greater than the corresponding PIN-fusion nuclease. The cleaving ability of the PIN-fusion nuclease was not improved even though the linker moiety between the PUF and RNA-cleavage domain was changed. Gel shift assays revealed that the RNA-binding properties of the PUF derivative used was not as good as wild type PUF. Improvement of the binding properties or the design method will allow the SNase-fusion nuclease to cleave an RNA target in mammalian animal cells and/or organisms. - Highlights: • A novel RNA restriction enzyme using SNase was developed tor cleave viral RNA. • Our enzyme cleaved influenza RNA with rates >120-fold higher rates a PIN-fusion one. • Our artificial enzyme with the L5 linker showed the highest RNA cleavage rate. • Our artificial enzyme site-selectively cleaved influenza RNA in vitro.

  7. Ramiprilate inhibits functional matrix metalloproteinase activity in Crohn's disease fistulas

    DEFF Research Database (Denmark)

    Efsen, Eva; Saermark, Torben; Hansen, Alastair

    2011-01-01

    from six controls were also included. Total functional MMP activity was measured by a high-pressure liquid chromatography (HPLC)-based, fluorogenic MMP-substrate cleavage assay, and the specific activity of MMP-2, -3 and -9 by the MMP Biotrak Activity Assay. The MMP inhibitors comprised ethylene...

  8. Cleavage of nicotinamide adenine dinucleotide by the ribosome-inactivating protein from Momordica charantia.

    Science.gov (United States)

    Vinkovic, M; Dunn, G; Wood, G E; Husain, J; Wood, S P; Gill, R

    2015-09-01

    The interaction of momordin, a type 1 ribosome-inactivating protein from Momordica charantia, with NADP(+) and NADPH has been investigated by X-ray diffraction analysis of complexes generated by co-crystallization and crystal soaking. It is known that the proteins of this family readily cleave the adenine-ribose bond of adenosine and related nucleotides in the crystal, leaving the product, adenine, bound to the enzyme active site. Surprisingly, the nicotinamide-ribose bond of oxidized NADP(+) is cleaved, leaving nicotinamide bound in the active site in the same position but in a slightly different orientation to that of the five-membered ring of adenine. No binding or cleavage of NADPH was observed at pH 7.4 in these experiments. These observations are in accord with current views of the enzyme mechanism and may contribute to ongoing searches for effective inhibitors.

  9. Endothelial sirtuin 1 deficiency perpetrates nephrosclerosis through downregulation of matrix metalloproteinase-14: relevance to fibrosis of vascular senescence.

    Science.gov (United States)

    Vasko, Radovan; Xavier, Sandhya; Chen, Jun; Lin, Chi Hua Sarah; Ratliff, Brian; Rabadi, May; Maizel, Julien; Tanokuchi, Rina; Zhang, Frank; Cao, Jian; Goligorsky, Michael S

    2014-02-01

    Sirtuin 1 (SIRT1) depletion in vascular endothelial cells mediates endothelial dysfunction and premature senescence in diverse cardiovascular and renal diseases. However, the molecular mechanisms underlying these pathologic effects remain unclear. Here, we examined the phenotype of a mouse model of vascular senescence created by genetically ablating exon 4 of Sirt1 in endothelial cells (Sirt1(endo-/-)). Under basal conditions, Sirt1(endo-/-) mice showed impaired endothelium-dependent vasorelaxation and angiogenesis, and fibrosis occurred spontaneously at low levels at an early age. In contrast, induction of nephrotoxic stress (acute and chronic folic acid-induced nephropathy) in Sirt1(endo-/-) mice resulted in robust acute renal functional deterioration followed by an exaggerated fibrotic response compared with control animals. Additional studies identified matrix metalloproteinase-14 (MMP-14) as a target of SIRT1. In the kidneys of Sirt1(endo-/-) mice, impaired angiogenesis, reduced matrilytic activity, and retention of the profibrotic cleavage substrates tissue transglutaminase and endoglin accompanied MMP-14 suppression. Furthermore, restoration of MMP-14 expression in SIRT1-depeleted mice improved angiogenic and matrilytic functions of the endothelium, prevented renal dysfunction, and attenuated nephrosclerosis. Our findings establish a novel mechanistic molecular link between endothelial SIRT1 depletion, downregulation of MMP-14, and the development of nephrosclerosis.

  10. A reduced graphene oxide-based fluorescence resonance energy transfer sensor for highly sensitive detection of matrix metalloproteinase 2.

    Science.gov (United States)

    Xi, Gaina; Wang, Xiaoping; Chen, Tongsheng

    2016-01-01

    A novel fluorescence nanoprobe (reduced nano-graphene oxide [nrGO]/fluorescein isothiocyanate-labeled peptide [Pep-FITC]) for ultrasensitive detection of matrix metalloproteinase 2 (MMP2) has been developed by engineering the Pep-FITC comprising the specific MMP2 substrate domain (PLGVR) onto the surface of nrGO particles through non-covalent linkage. The nrGO was obtained by water bathing nano-graphene oxide under 90°C for 4 hours. After mixing the nrGO and Pep-FITC for 30 seconds, the fluorescence from Pep-FITC was almost completely quenched due to the fluorescence resonance energy transfer between fluorescein isothiocyanate (FITC) and nrGO. Upon cleavage of the amide bond between Leu and Gly in the Pep-FITC by protease-MMP2, the FITC bound to nrGO was separated from nrGO surface, disrupting the fluorescence resonance energy transfer process and resulting in fluorescence recovery of FITC. Under optimal conditions, the fluorescence recovery of nrGO/Pep-FITC was found to be directly proportional to the concentration of MMP2 within 0.02-0.1 nM. The detection limit of the nrGO/Pep-FITC was determined to be 3 pM, which is approximately tenfold lower than that of the unreduced carboxylated nano-graphene oxide/Pep-FITC probe.

  11. The role of extracellular matrix metalloproteinase inducer (EMMPRIN) in the regulation of bovine endometrial cell functions.

    Science.gov (United States)

    Mishra, Birendra; Kizaki, Keiichiro; Sato, Takashi; Ito, Akira; Hashizume, Kazuyoshi

    2012-06-01

    Extracellular matrix metalloproteinase inducer (EMMPRIN) is a cell surface glycoprotein that stimulates the production of several matrix metalloproteinases (MMPs) for tissue remodeling. Previously, we detected EMMPRIN in the bovine endometrium, and it is mainly expressed in the luminal and glandular epithelium whereas MMPs are expressed in the underlying stroma. From this expression pattern, we hypothesized that EMMPRIN may regulate stromal MMPs in endometrial cell functions. To test this hypothesis, a coculture of epithelial and stromal cells was performed using a transwell system. In the coculture, epithelial cells were cultured on the insert membrane and stromal cell on the surface of well plates. Expression of stromal MMP-2 and MMP-14 was significantly higher in coculture with epithelial cell. Further, with the addition of anti-EMMPRIN antibody into the epithelial cell compartment, the expression of stromal EMMPRIN and MMP-2 and MMP-14 was decreased. To identify the active site of EMMPRIN for the augmentation of MMPs, EMMPRIN synthetic peptides that correspond to the extracellular loop domain-I (EM1, EM2, EM3, and EM4) were added into the epithelial cell compartment, and only EM2 at a higher dose interfered with EMMPRIN-mediated expression of MMP-14. Next, we examined the effects of progesterone and/or estrogen on the expression of EMMPRIN, MMP-2, and MMP-14. Progesterone (300 nM) significantly stimulated the expression of EMMPRIN but had no effects on any of the MMPs. These results suggest that EMMPRIN derived from epithelial cells regulates MMPs in the endometrium under progesterone-rich conditions and may thereby modulate bovine endometrial cell functions during gestation.

  12. Elevation of Matrix Metalloproteinases in Different Areas of Ascending Aortic Aneurysms in Patients with Bicuspid and Tricuspid Aortic Valves

    Directory of Open Access Journals (Sweden)

    Salah A. Mohamed

    2012-01-01

    Full Text Available Our aim is to investigate the elevation of matrix proteins in tissues obtained from distal, above the sinotubular junction (proximal, concave, and convex sites of aneurysms in the ascending aorta using a simultaneous multiplex protein detection system. Tissues were collected from 41 patients with ascending aortic aneurysms. A total of 31 patients had a bicuspid aortic valve (BAV, whereas 10 had a tricuspid aortic valve (TAV. Concave and convex aortic site samples were collected from all patients, whereas proximal and distal convexity samples were obtained from 19 patients with BAV and 7 patients with TAV. Simultaneous detection of matrix metalloproteinases (MMPs and their inhibitors (TIMPs was performed at each of the four aortic sites. MMP-2 levels were higher in the concave aortic sites than in the convex aortic sites. In contrast, MMP-8 levels were higher in the convex sites than in the concave sites, as were MMP-9 levels. In both BAV and TAV patients, TIMP-3 levels were higher in the concave sites than in the convex sites. However, TIMP-2 and TIMP-4 levels were significantly elevated in the sinotubular proximal aorta of BAV patients. Simultaneous detection of MMPs and TIMPs revealed different levels at different aortic sites in the same patient.

  13. Detection of siRNA Mediated Target mRNA Cleavage Activities in Human Cells by a Novel Stem-Loop Array RT-PCR Analysis

    Science.gov (United States)

    2016-09-07

    sequences of the target mRNA, and a double stranded stem at the 5′ end that forms a stem -loop to function as a forceps to stabilize the secondary...E-mjournal homepage: www.elsevier.com/locate/bbrepDetection of siRNA-mediated target mRNA cleavage activities in human cells by a novel stem -loop...challenges for the accurate and efficient detection and verification of cleavage sites on target mRNAs. Here we used a sensitive stem -loop array reverse

  14. Cleavage of a recombinant human immunoglobulin A2 (IgA2)-IgA1 hybrid antibody by certain bacterial IgA1 proteases

    DEFF Research Database (Denmark)

    Senior, B; Dunlop, JI; Batten, MR

    2000-01-01

    , Streptococcus pneumoniae, S. sanguis, Neisseria meningitidis types 1 and 2, N. gonorrhoeae types 1 and 2, and Haemophilus influenzae type 2. Thus, for these enzymes the recognition site for IgA1 cleavage is contained within half of the IgA1 hinge region; additional distal elements, if required, are provided...... by either an IgA1 or an IgA2 framework. In contrast, the IgA2/A1 hybrid appeared to be resistant to cleavage with S. oralis and some H. influenzae type 1 IgA1 proteases, suggesting these enzymes require additional determinants for efficient substrate recognition....

  15. Structure-Based Design and Synthesis of Potent and Selective Matrix Metalloproteinase 13 Inhibitors.

    Science.gov (United States)

    Choi, Jun Yong; Fuerst, Rita; Knapinska, Anna M; Taylor, Alexander B; Smith, Lyndsay; Cao, Xiaohang; Hart, P John; Fields, Gregg B; Roush, William R

    2017-07-13

    We describe the use of comparative structural analysis and structure-guided molecular design to develop potent and selective inhibitors (10d and (S)-17b) of matrix metalloproteinase 13 (MMP-13). We applied a three-step process, starting with a comparative analysis of the X-ray crystallographic structure of compound 5 in complex with MMP-13 with published structures of known MMP-13·inhibitor complexes followed by molecular design and synthesis of potent but nonselective zinc-chelating MMP inhibitors (e.g., 10a and 10b). After demonstrating that the pharmacophores of the chelating inhibitors (S)-10a, (R)-10a, and 10b were binding within the MMP-13 active site, the Zn 2+ chelating unit was replaced with nonchelating polar residues that bridged over the Zn 2+ binding site and reached into a solvent accessible area. After two rounds of structural optimization, these design approaches led to small molecule MMP-13 inhibitors 10d and (S)-17b, which bind within the substrate-binding site of MMP-13 and surround the catalytically active Zn 2+ ion without chelating to the metal. These compounds exhibit at least 500-fold selectivity versus other MMPs.

  16. of Matrix Metalloproteinase-9 and Neutrophil Gelatinase-Associated Lipocalin

    Directory of Open Access Journals (Sweden)

    De Caridi Giovanni

    2015-01-01

    Full Text Available The association of an axillary artery aneurysm and an abdominal aortic aneurysm is extremely rare. In this study, we describe this association in a 69 year-old-man. We measured this patient’s metalloproteinases (MMPs and Neutrophil Gelatinase - Associated Lipocalin (NGAL levels over a three years period before the abdominal aortic aneurysm rupture. We speculate that high serium levels of MMPs and NGAL may have a prognostic role and may predict aneurysm rupture in patients with an uncommon association of arterial aneurysms.

  17. Drosha regulates gene expression independently of RNA cleavage function

    DEFF Research Database (Denmark)

    Gromak, Natalia; Dienstbier, Martin; Macias, Sara

    2013-01-01

    Drosha is the main RNase III-like enzyme involved in the process of microRNA (miRNA) biogenesis in the nucleus. Using whole-genome ChIP-on-chip analysis, we demonstrate that, in addition to miRNA sequences, Drosha specifically binds promoter-proximal regions of many human genes in a transcription......-dependent manner. This binding is not associated with miRNA production or RNA cleavage. Drosha knockdown in HeLa cells downregulated nascent gene transcription, resulting in a reduction of polyadenylated mRNA produced from these gene regions. Furthermore, we show that this function of Drosha is dependent on its N......-terminal protein-interaction domain, which associates with the RNA-binding protein CBP80 and RNA Polymerase II. Consequently, we uncover a previously unsuspected RNA cleavage-independent function of Drosha in the regulation of human gene expression....

  18. Polycystin-1 Cleavage and the Regulation of Transcriptional Pathways

    Science.gov (United States)

    Merrick, David; Bertuccio, Claudia A.; Chapin, Hannah C.; Lal, Mark; Chauvet, Veronique; Caplan, Michael J.

    2013-01-01

    Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic cause of end stage renal disease, affecting ~1 in 1,000 people. The disease is characterized by the development of numerous large fluid filled renal cysts over the course of decades. These cysts compress the surrounding renal parenchyma and impair its function. Mutations in two genes are responsible for ADPKD. The protein products of both of these genes, polycystin-1 and polycystin-2, localize to the primary cilium and participate in a wide variety of signaling pathways. Polycystin-1 undergoes several proteolytic cleavages that produce fragments that manifest biological activities. Recent results suggest that the production of polycystin-1 cleavage fragments is necessary and sufficient to account for at least some, although certainly not all, of the physiological functions of the parent protein. PMID:23824180

  19. Matrix metalloproteinases in gastric inflammation and cancer : clinical relevance and prognostic impact

    NARCIS (Netherlands)

    Kubben, Francois Jozef Gerard Marie

    2007-01-01

    The studies in this thesis describe the clinical impact of several matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in H. pylori-induced gastritis and gastric cancer. In patients with H. pylori-induced gastritis, significantly increased mucosal MMP-9 levels were

  20. Cleavage of cohesin rings coordinates the separation of centrioles and chromatids.

    Science.gov (United States)

    Schöckel, Laura; Möckel, Martin; Mayer, Bernd; Boos, Dominik; Stemmann, Olaf

    2011-07-10

    Cohesin pairs sister chromatids by forming a tripartite Scc1-Smc1-Smc3 ring around them. In mitosis, cohesin is removed from chromosome arms by the phosphorylation-dependent prophase pathway. Centromeric cohesin is protected by shugoshin 1 and protein phosphatase 2A (Sgo1-PP2A) and opened only in anaphase by separase-dependent cleavage of Scc1 (refs 4-6). Following chromosome segregation, centrioles loosen their tight orthogonal arrangement, which licenses later centrosome duplication in S phase. Although a role of separase in centriole disengagement has been reported, the molecular details of this process remain enigmatic. Here, we identify cohesin as a centriole-engagement factor. Both premature sister-chromatid separation and centriole disengagement are induced by ectopic activation of separase or depletion of Sgo1. These unscheduled events are suppressed by expression of non-cleavable Scc1 or inhibition of the prophase pathway. When endogenous Scc1 is replaced by artificially cleavable Scc1, the corresponding site-specific protease triggers centriole disengagement. Separation of centrioles can alternatively be induced by ectopic cleavage of an engineered Smc3. Thus, the chromosome and centrosome cycles exhibit extensive parallels and are coordinated with each other by dual use of the cohesin ring complex.

  1. Relationship between synthesis and cleavage of poliovirus-specific proteins.

    OpenAIRE

    Thomas, A A; Voorma, H O; Boeye, A

    1983-01-01

    Poliovirus proteinase was studied in vitro in lysates from poliovirus-infected HeLa cells. Preincubation of these lysates caused (i) a reduction in poliovirus proteinase activity and (ii) a partial dependence on exogenous mRNA for optimal translation. Proteins translated from endogenous poliovirus RNA in preincubated extracts from virus-infected HeLa cells are poorly cleaved. This cleavage deficiency is alleviated by adding fresh poliovirus RNA to the translation system, thus, allowing re-ini...

  2. Effects of Cysteamine on Sheep Embryo Cleavage Rates

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    Sinem Ö. ENGİNLER

    2015-01-01

    Full Text Available Oxidative stress during in vitro culture leads to defects in development of gametes and embryos. Several antioxidants such as cysteamine, L-ascorbic acid, beta mercaptoethanol, cysteine, glutathione, proteins, vitamins have been used to supplement culture media to counter the oxidative stress. This study was conducted to detect the effect of adding cysteamine to the maturation medium to subsequent cleavage rates of sheep embryos. Totally 604 ovaries were obtained by ten replica and 2060 oocytes were collected. The cumulus oocyte complexes were recovered by the slicing method. A total of 1818 selected oocytes were divided into two groups and used for maturation (88.25%. The first group was created as supplemented with cysteamine (Group A and second group (Group B, control without cysteamine in TCM-199. The two groups were incubated for 24 h at 38.8 °C in an atmosphere of 5% CO2 in humidified air for in vitro maturation (IVM. After IVM, oocytes were fertilized with 50 x 107 / mL fresh ram semen in BSOF medium for 18 h. After fertilization, maturation groups were divided into two subgroups with different culture media: Group AI-SOF (Synthetic Oviduct Fluid medium, Group AII-CR1aa (Charles Rosencrans medium, Group BI-SOF and Group BII-CR1aa were achieved. Cleavage rates were evaluated at day 2. post insemination. The rates of cleavage were detected as 59.54% (184/309, 55.44% (173/312, 65.34% (215/329, 59.34% (200/337 respectively, with showing no statistically significant difference between the groups at the level of P>0.05. In conclusion, supplementing cysteamine to maturation media in TCM-199 did not affect the cleavage rates of sheep embryos in SOF and CR1aa culture media.

  3. Deletion of the thrombin cleavage domain of osteopontin mediates breast cancer cell adhesion, proteolytic activity, tumorgenicity, and metastasis

    International Nuclear Information System (INIS)

    Beausoleil, Michel S; Schulze, Erika B; Goodale, David; Postenka, Carl O; Allan, Alison L

    2011-01-01

    Osteopontin (OPN) is a secreted phosphoprotein often overexpressed at high levels in the blood and primary tumors of breast cancer patients. OPN contains two integrin-binding sites and a thrombin cleavage domain located in close proximity to each other. To study the role of the thrombin cleavage site of OPN, MDA-MB-468 human breast cancer cells were stably transfected with either wildtype OPN (468-OPN), mutant OPN lacking the thrombin cleavage domain (468-ΔTC) or an empty vector (468-CON) and assessed for in vitro and in vivo functional differences in malignant/metastatic behavior. All three cell lines were found to equivalently express thrombin, tissue factor, CD44, αvβ5 integrin and β1 integrin. Relative to 468-OPN and 468-CON cells, 468-ΔTC cells expressing OPN with a deleted thrombin cleavage domain demonstrated decreased cell adhesion (p < 0.001), decreased mRNA expression of MCAM, maspin and TRAIL (p < 0.01), and increased uPA expression and activity (p < 0.01) in vitro. Furthermore, injection of 468-ΔTC cells into the mammary fat pad of nude mice resulted in decreased primary tumor latency time (p < 0.01) and increased primary tumor growth and lymph node metastatic burden (p < 0.001) compared to 468-OPN and 468-CON cells. The results presented here suggest that expression of thrombin-uncleavable OPN imparts an early tumor formation advantage as well as a metastatic advantage for breast cancer cells, possibly due to increased proteolytic activity and decreased adhesion and apoptosis. Clarification of the mechanisms responsible for these observations and the translation of this knowledge into the clinic could ultimately provide new therapeutic opportunities for combating breast cancer

  4. Numerical modeling of ductile tearing effects on cleavage fracture toughness

    International Nuclear Information System (INIS)

    Dodds, R.H. Jr.; Tang, M.; Anderson, T.L.

    1994-05-01

    Experimental studies demonstrate a significant effect of specimen size, a/W ratio and prior ductile tearing on cleavage fracture toughness values (J c ) measured in the ductile-to-brittle transition region of ferritic materials. In the lower-transition region, cleavage fracture often occurs under conditions of large-scale yielding but without prior ductile crack extension. The increased toughness develops when plastic zones formed at the crack tip interact with nearby specimen surfaces which relaxes crack-tip constraint (stress triaxiality). In the mid-to-upper transition region, small amounts of ductile crack extension (often c -values. Previous work by the authors described a micromechanics fracture model to correct measured J c -values for the mechanistic effects of large-scale yielding. This new work extends the model to also include the influence of ductile crack extension prior to cleavage. The paper explores development of the new model, provides necessary graphs and procedures for its application and demonstrates the effects of the model on fracture data sets for two pressure vessel steels (A533B and A515)

  5. Cleavage mechanoluminescence in elemental and III-V semiconductors

    International Nuclear Information System (INIS)

    Chandra, B.P.; Patel, R.P.; Gour, Anubha S.; Chandra, V.K.; Gupta, R.K.

    2003-01-01

    The present paper reports the theory of mechanoluminescence (ML) produced during cleavage of elemental and III-V semiconductors. It seems that the formation of crack-induced localized states is responsible for the ML excitation produced during the cleavage of elemental and III-V semiconductors. According to this mechanism, as the atoms are drawn away from each other in an advancing crack tip, the decreasing wave function overlap across the crack may result in localized states which is associated with increasing electron energy. If the energy of these localized states approach that of the conduction band, transition to the conduction band via tunnelling would be possible, creating minority carriers, and consequently the electron-hole recombination may give rise to mechanoluminescence. When an elemental or III-V semiconductor is cleaved, initially the ML intensity increases with time, attains a peak value I m at the time t m corresponding to completion of the cleavage of the semiconductor, and then it decreases following power law decay. Expressions are derived for the ML intensity I m corresponding to the peak of the ML intensity versus time curve and for the total ML intensity I T . It is shown that both I m and I T should increase directly with the area of the newly created surfaces of the crystals. From the measurements of the ML intensity, the velocity of crack propagation in material can be determined by using the relation v=H/t m

  6. Specific in vitro cleavage of Mason-Pfizer monkey virus capsid protein: evidence for a potential role of retroviral protease in early stages of infection

    International Nuclear Information System (INIS)

    Rumlova, Michaela; Ruml, Tomas; Pohl, Jan; Pichova, Iva

    2003-01-01

    Processing of Gag polyproteins by viral protease (PR) leads to reorganization of immature retroviral particles and formation of a ribonucleoprotein core. In some retroviruses, such as HIV and RSV, cleavage of a spacer peptide separating capsid and nucleocapsid proteins is essential for the core formation. We show here that no similar spacer peptide is present in the capsid-nucleocapsid (CA-NC) region of Mason-Pfizer monkey virus (M-PMV) and that the CA protein is cleaved in vitro by the PR within the major homology region (MHR) and the NC protein in several sites at the N-terminus. The CA cleavage product was also identified shortly after penetration of M-PMV into COS cells, suggesting that the protease-catalyzed cleavage is involved in core disintegration

  7. Sequence adaptations affecting cleavage of the VP1/2A junction by the 3C protease in foot-and-mouth disease virus-infected cells

    DEFF Research Database (Denmark)

    Gullberg, Maria; Polacek, Charlotta; Belsham, Graham

    2014-01-01

    The foot-and-mouth disease virus (FMDV) capsid protein precursor P1-2A is cleaved by the virus-encoded 3C protease to VP0, VP3, VP1 and 2A. It was shown previously that modification of a single amino acid residue (K210E) within the VP1 protein and close to the VP1/2A cleavage site, inhibited...... cleavage of this junction and produced 'self-tagged' virus particles. A second site substitution (E83K) within VP1 was also observed within the rescued virus [Gullberg et al. (2013). J Virol 87: , 11591-11603]. It was shown here that introduction of this E83K change alone into a serotype O virus resulted...... in the rapid accumulation of a second site substitution within the 2A sequence (L2P), which also blocked VP1/2A cleavage. This suggests a linkage between the E83K change in VP1 and cleavage of the VP1/2A junction. Cells infected with viruses containing the VP1 K210E or the 2A L2P substitutions contained...

  8. [Recent knowledge about intestinal absorption and cleavage of carotenoids].

    Science.gov (United States)

    Borel, P; Drai, J; Faure, H; Fayol, V; Galabert, C; Laromiguière, M; Le Moël, G

    2005-01-01

    Our knowledge about intestinal absorption and cleavage of carotenoids has rapidly grown during the last years. New facts about carotenoid absorption have emerged while some controversies about cleavage are close to end. The knowledge of the absorption and conversion processes is indispensable to understand and interpret the perturbations that can occur in the metabolism of carotenoids and vitamin A. Recently, it has been shown that the absorption of certain carotenoids is not passive - as believed for a long time - but is a facilitated process that requires, at least for lutein, the class B-type 1 scavenger receptor (SR-B1). Various epidemiological and clinical studies have shown wide variations in carotenoid absorption from one subject to another, such differences are now explained by the structure of the concerned carotenoid, by the nature of the food that is absorbed with the carotenoid, by diverse exogenous factors like the intake of medicines or interfering components, by diet factors, by genetic factors, and by the nutritional status of the subject. Recently, the precise mechanism of beta-carotene cleavage by betabeta-carotene 15,15' monooxygenase (EC 1.14.99.36) - formerly called beta-carotene 15,15' dioxygenase (ex EC 1.13.11.21) - has been discovered, and a second enzyme which cleaves asymmetrically the beta-carotene molecule has been found. beta-carotene 15,15' monooxygenase only acts on the 15,15' bond, thus forming two molecules of retinal from one molecule of beta-carotene by central cleavage. Even though the betabeta-carotene 15,15' monooxygenase is much more active on the beta-carotene molecule, a study has shown that it can act on all carotenoids. Searchers now agree that other enzymes that can catalyse an eccentric cleavage of carotenoids probably exist, but under physiological conditions the betabeta-carotene 15,15' monooxygenase is by far the most active, and it is mainly effective in the small bowel mucosa and in the liver. However the

  9. Structure and evolutionary aspects of matrix metalloproteinases: a brief overview.

    Science.gov (United States)

    Das, Sudip; Mandal, Malay; Chakraborti, Tapati; Mandal, Amritlal; Chakraborti, Sajal

    2003-11-01

    The matrix metalloproteinases (MMPs) are zinc dependent endopeptidases known for their ability to cleave one or several extracellular matrix (ECM) constituents, as well as non-matrix proteins. They comprise a large family of proteinases that share common structural and functional elements and are products of different genes. All members of this family contain a signal peptide, a propeptide and a catalytic domain. The catalytic domain contains two zinc ions and at least one calcium ion coordinated to various residues. All MMPs, with the exception matrilysin, have a hemopexin/vitronectin-like domain that is connected to the catalytic domain by a hinge or linker region. The hemopexin-like domain influences tissue inhibitor of metalloproteinases (TIMP) binding, the binding of certain substrates, membrane activation, and some proteolytic activities. It has been proposed that the origin of MMPs could be traced to before the emergence of vertebrates from invertebrates. It appears conceivable that the domain assemblies occurred at an early stage of the diversification of different MMPs and that they progressed through the evolutionary process independent of one another, and perhaps parallel to each other.

  10. Expression of extracellular matrix metalloproteinase inducer in odontogenic cysts.

    Science.gov (United States)

    Ali, Mohammad Abdulhadi Abbas

    2008-08-01

    Extracellular matrix metalloproteinase inducer (EMMPRIN) is known to induce matrix metalloproteinase (MMP) production. The expression of EMMPRIN in odontogenic cysts has not been previously studied. This study was done to determine the presence and the variability of EMMPRIN expression in various types of odontogenic cysts. An immunohistochemical study using a polyclonal anti-EMMPRIN antibody was done using 48 odontogenic cyst cases: 13 odontogenic keratocysts (OKCs), 18 dentigerous cysts (DCs), and 17 periapical cysts (PAs). Twelve cases of normal dental follicles (DFs) were also included in this study for comparison. EMMPRIN immunoreactivity was detected in all of the cysts and DFs studied. In odontogenic cysts, EMMPRIN immunoreactivity was generally higher in basal cells than in suprabasal cells. The overall EMMPRIN expression in the epithelial lining of the 3 different types of odontogenic cyst was significantly higher than in the DFs. Overall EMMPRIN expression was also found to be significantly higher in the epithelial lining of OKCs than in the other types of cysts. This study confirmed that EMMPRIN is present in odontogenic cysts and DFs. The higher EMMPRIN expression in OKCs suggests that it may be involved in the aggressive behavior of this type of cyst.

  11. New intracellular activities of matrix metalloproteinases shine in the moonlight.

    Science.gov (United States)

    Jobin, Parker G; Butler, Georgina S; Overall, Christopher M

    2017-11-01

    Adaption of a single protein to perform multiple independent functions facilitates functional plasticity of the proteome allowing a limited number of protein-coding genes to perform a multitude of cellular processes. Multifunctionality is achievable by post-translational modifications and by modulating subcellular localization. Matrix metalloproteinases (MMPs), classically viewed as degraders of the extracellular matrix (ECM) responsible for matrix protein turnover, are more recently recognized as regulators of a range of extracellular bioactive molecules including chemokines, cytokines, and their binders. However, growing evidence has convincingly identified select MMPs in intracellular compartments with unexpected physiological and pathological roles. Intracellular MMPs have both proteolytic and non-proteolytic functions, including signal transduction and transcription factor activity thereby challenging their traditional designation as extracellular proteases. This review highlights current knowledge of subcellular location and activity of these "moonlighting" MMPs. Intracellular roles herald a new era of MMP research, rejuvenating interest in targeting these proteases in therapeutic strategies. This article is part of a Special Issue entitled: Matrix Metalloproteinases edited by Rafael Fridman. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Curcumin: a potential candidate for matrix metalloproteinase inhibitors.

    Science.gov (United States)

    Kumar, Dileep; Kumar, Manish; Saravanan, Chinnadurai; Singh, Sushil Kumar

    2012-10-01

    Curcumin, a natural yellow pigment of turmeric, has become focus of interest with regard to its role in regulation of matrix metalloproteinases (MMPs). MMPs are metal-dependent endopeptidases capable of degrading components of the extracellular matrix. MMPs are involved in chronic diseases such as arthritis, Alzheimer's disease, psoriasis, chronic obstructive pulmonary disease, asthma, cancer, neuropathic pain, and atherosclerosis. Curcumin regulates the expression and secretion of various MMPs. This review documents the matrix metalloproteinase inhibitory activity of curcumin on various diseases viz., cancer, arthritis, and ulcer. Finally, the steps to be taken for getting potent curcuminoids have also been discussed in the structure-activity relationship (SAR) section. From this review, readers can get answer to the question: Is curcumin a potential MMPI candidate? Numerous approaches have been taken to beget a molecule with specificity restricted to a particular MMP as well as good oral bioavailability; however, nearly all the molecules lack these criteria. Using quantitative structure-activity relationship (QSAR) modeling and virtual screening, new analogs of curcumin can be designed which will be selectively inhibiting different MMPs.

  13. Remote Exosites of the Catalytic Domain of Matrix Metalloproteinase-12 Enhance Elastin Degradation┼

    Science.gov (United States)

    Fulcher, Yan G.; Van Doren, Steven R.

    2011-01-01

    How does matrix metalloproteinase-12 (MMP-12 or metalloelastase) degrade elastin with high specific activity? NMR suggested soluble elastin to cover surfaces of MMP-12 far from its active site. Two of these surfaces have been found, by mutagenesis guided by the BINDSIght approach, to affect degradation and affinity for elastin substrates but not a small peptide substrate. Main exosite 1 has been extended out to Asp124 that binds calcium. Novel exosite 2 comprises residues from the II–III loop and β-strand I near the back of the catalytic domain. The high exposure of these distal exosites may make them accessible to elastin made more flexible by partial hydrolysis. Importantly, combination of a lesion at each of exosites 1 and 2 and active site decreased catalytic competence towards soluble elastin by 13- to 18-fold to the level of MMP-3, homologue and poor elastase. Double mutant cycle analysis of conservative mutations of Met156 (exosite 2) and either Asp124 (exosite 1) or Ile180 (active site) had additive effects. Compared to polar substitutions observed in other MMPs, Met156 enhanced affinity and Ile180 kcat for soluble elastin. Both residues detracted from the higher folding stability with polar mutations. This resembles the trend in enzymes of an inverse relationship between folding stability and activity. Restoring Asp124 from combination mutants enhanced kcat for soluble elastin. In elastin degradation, exosites 1 and 2 contributed independently of each other and Ile180 at the active site, but with partial coupling to Ala182 near the active site. The concept of weak, separated interactions coalescing somewhat independently can be extended to this proteolytic digestion of a protein from fibrils. PMID:21967233

  14. DIDS prevents ischemic membrane degradation in cultured hippocampal neurons by inhibiting matrix metalloproteinase release.

    Directory of Open Access Journals (Sweden)

    Matthew E Pamenter

    Full Text Available During stroke, cells in the infarct core exhibit rapid failure of their permeability barriers, which releases ions and inflammatory molecules that are deleterious to nearby tissue (the penumbra. Plasma membrane degradation is key to penumbral spread and is mediated by matrix metalloproteinases (MMPs, which are released via vesicular exocytosis into the extracellular fluid in response to stress. DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid preserves membrane integrity in neurons challenged with an in vitro ischemic penumbral mimic (ischemic solution: IS and we asked whether this action was mediated via inhibition of MMP activity. In cultured murine hippocampal neurons challenged with IS, intracellular proMMP-2 and -9 expression increased 4-10 fold and extracellular latent and active MMP isoform expression increased 2-22 fold. MMP-mediated extracellular gelatinolytic activity increased ∼20-50 fold, causing detachment of 32.1±4.5% of cells from the matrix and extensive plasma membrane degradation (>60% of cells took up vital dyes and >60% of plasma membranes were fragmented or blebbed. DIDS abolished cellular detachment and membrane degradation in neurons and the pathology-induced extracellular expression of latent and active MMPs. DIDS similarly inhibited extracellular MMP expression and cellular detachment induced by the pro-apoptotic agent staurosporine or the general proteinase agonist 4-aminophenylmercuric acetate (APMA. Conversely, DIDS-treatment did not impair stress-induced intracellular proMMP production, nor the intracellular cleavage of proMMP-2 to the active form, suggesting DIDS interferes with the vesicular extrusion of MMPs rather than directly inhibiting proteinase expression or activation. In support of this hypothesis, an antagonist of the V-type vesicular ATPase also inhibited extracellular MMP expression to a similar degree as DIDS. In addition, in a proteinase-independent model of vesicular exocytosis, DIDS

  15. Analysis of X-ray structures of matrix metalloproteinases via chaotic map clustering.

    Science.gov (United States)

    Giangreco, Ilenia; Nicolotti, Orazio; Carotti, Angelo; De Carlo, Francesco; Gargano, Gianfranco; Bellotti, Roberto

    2010-10-08

    Matrix metalloproteinases (MMPs) are well-known biological targets implicated in tumour progression, homeostatic regulation, innate immunity, impaired delivery of pro-apoptotic ligands, and the release and cleavage of cell-surface receptors. With this in mind, the perception of the intimate relationships among diverse MMPs could be a solid basis for accelerated learning in designing new selective MMP inhibitors. In this regard, decrypting the latent molecular reasons in order to elucidate similarity among MMPs is a key challenge. We describe a pairwise variant of the non-parametric chaotic map clustering (CMC) algorithm and its application to 104 X-ray MMP structures. In this analysis electrostatic potentials are computed and used as input for the CMC algorithm. It was shown that differences between proteins reflect genuine variation of their electrostatic potentials. In addition, the analysis has been also extended to analyze the protein primary structures and the molecular shapes of the MMP co-crystallised ligands. The CMC algorithm was shown to be a valuable tool in knowledge acquisition and transfer from MMP structures. Based on the variation of electrostatic potentials, CMC was successful in analysing the MMP target family landscape and different subsites. The first investigation resulted in rational figure interpretation of both domain organization as well as of substrate specificity classifications. The second made it possible to distinguish the MMP classes, demonstrating the high specificity of the S1' pocket, to detect both the occurrence of punctual mutations of ionisable residues and different side-chain conformations that likely account for induced-fit phenomena. In addition, CMC demonstrated a potential comparable to the most popular UPGMA (Unweighted Pair Group Method with Arithmetic mean) method that, at present, represents a standard clustering bioinformatics approach. Interestingly, CMC and UPGMA resulted in closely comparable outcomes, but often

  16. Analysis of X-ray Structures of Matrix Metalloproteinases via Chaotic Map Clustering

    Directory of Open Access Journals (Sweden)

    Gargano Gianfranco

    2010-10-01

    Full Text Available Abstract Background Matrix metalloproteinases (MMPs are well-known biological targets implicated in tumour progression, homeostatic regulation, innate immunity, impaired delivery of pro-apoptotic ligands, and the release and cleavage of cell-surface receptors. With this in mind, the perception of the intimate relationships among diverse MMPs could be a solid basis for accelerated learning in designing new selective MMP inhibitors. In this regard, decrypting the latent molecular reasons in order to elucidate similarity among MMPs is a key challenge. Results We describe a pairwise variant of the non-parametric chaotic map clustering (CMC algorithm and its application to 104 X-ray MMP structures. In this analysis electrostatic potentials are computed and used as input for the CMC algorithm. It was shown that differences between proteins reflect genuine variation of their electrostatic potentials. In addition, the analysis has been also extended to analyze the protein primary structures and the molecular shapes of the MMP co-crystallised ligands. Conclusions The CMC algorithm was shown to be a valuable tool in knowledge acquisition and transfer from MMP structures. Based on the variation of electrostatic potentials, CMC was successful in analysing the MMP target family landscape and different subsites. The first investigation resulted in rational figure interpretation of both domain organization as well as of substrate specificity classifications. The second made it possible to distinguish the MMP classes, demonstrating the high specificity of the S1' pocket, to detect both the occurrence of punctual mutations of ionisable residues and different side-chain conformations that likely account for induced-fit phenomena. In addition, CMC demonstrated a potential comparable to the most popular UPGMA (Unweighted Pair Group Method with Arithmetic mean method that, at present, represents a standard clustering bioinformatics approach. Interestingly, CMC and

  17. The plasma and peritoneal fluid concentrations of matrix metalloproteinase-9 are elevated in patients with endometriosis.

    Science.gov (United States)

    Liu, Haiping; Wang, Jianye; Wang, Haiyu; Tang, Ning; Li, Yunfei; Zhang, Yan; Hao, Tianyu

    2016-09-01

    Enzyme matrix metalloproteinase-9 is a member of the matrix metalloproteinase family, which is critical to normal tissue remodelling during embryogenesis and wound healing. In patients with endometriosis, increased expression and activity of matrix metalloproteinase-9 have been observed in ectopic endometrium, but the plasma and peritoneal fluid concentrations of matrix metalloproteinase-9 in patients with endometriosis and their relation to disease severity have not been clear. The aim of the study was to investigate the concentrations of matrix metalloproteinase-9 in plasma and peritoneal fluid of patients with endometriosis. A prospective case-control study was conducted in Jinan Military General Hospital between January 2010 and December 2013. Fifty patients with proven endometriosis and 26 endometriosis-free controls were enrolled in this study. Patients with endometriosis were evaluated and divided into moderate/severe endometriosis group (stage I-II, n = 26) and minimal/mild endometriosis group (stage III-IV, n = 24) according to the revised criteria of the American Society for Reproductive Medicine. Blood samples and peritoneal fluid were obtained from both patients and controls. Matrix metalloproteinase-9 was measured using enzyme-linked immunosorbent assay in plasma and peritoneal fluid. The concentration of matrix metalloproteinase-9 between different groups was compared and its correlation to disease severity was analysed. Plasma and peritoneal fluid concentrations of matrix metalloproteinase-9 in patients with endometriosis were higher than that in controls. In addition, those patients with moderate/severe endometriosis had significantly higher plasma and peritoneal fluid concentrations of matrix metalloproteinase-9 compared to those with minimal/mild endometriosis. Matrix metalloproteinase-9 concentrations in plasma and peritoneal fluid were both positively correlated with severity of endometriosis and plasma matrix metalloproteinase-9

  18. Matrix metalloproteinase 2 (MMP-2) levels are increased in active acromegaly patients.

    Science.gov (United States)

    Karci, Alper Cagri; Canturk, Zeynep; Tarkun, Ilhan; Cetinarslan, Berrin

    2017-07-01

    During follow-up of acromegaly patients, there is a discordance rate of 30% between the measurements of growth hormone and insulin-like growth factor-1 levels. Further tests are required to determine disease activity in patients with discordant results. This study was planned to investigate an association of serum levels of matrix metalloproteinase-2, matrix metalloproteinase-9, and cathepsin B with disease activity in acromegaly patients. In this study, 64 acromegaly patients followed in our clinic were divided into two groups according to the 2010 consensus criteria for cure of acromegaly as patients with active disease (n = 24) and patients with controlled disease (n = 40). Serum matrix metalloproteinase-2, matrix metalloproteinase-9, and cathepsin B levels were measured by the enzyme-linked immunosorbent assay method. The mean serum matrix metalloproteinase-2 level was significantly higher in the active acromegaly patients than in the controlled acromegaly patients (150.1 ± 54.5 ng/mL vs. 100.2 ± 44.6 ng/mL; p matrix metalloproteinase-9 and cathepsin B levels (p = 0.205 and p = 0.598, respectively). Serum matrix metalloproteinase-2 levels of 118.3 ng/mL and higher had a sensitivity of 75% and a specificity of 77.5% in determining active disease. The risk of active acromegaly was 3.3 fold higher in the patients with a matrix metalloproteinase-2 level of >118.3 ng/mL than in the patients with a matrix metalloproteinase-2 level of matrix metalloproteinase-2 level is increased in the active acromegaly patients and a threshold value in determining active disease was defined for serum matrix metalloproteinase-2 level. This study is the first to compare acromegaly patients having active or controlled disease in terms of matrix metalloproteinase-2 and matrix metalloproteinase-9 levels. The results need to be confirmed by a study that will be conducted in a larger patient group also including a healthy control group to demonstrate the

  19. Identification of potent inhibitors against snake venom metalloproteinase (SVMP) using molecular docking and molecular dynamics studies.

    Science.gov (United States)

    Chinnasamy, Sathishkumar; Chinnasamy, Selvakkumar; Nagamani, Selvaraman; Muthusamy, Karthikeyan

    2015-01-01

    Snake venom metalloproteinase (SVMP) (Echis coloratus (Carpet viper) is a multifunctional enzyme that is involved in producing several symptoms that follow a snakebite, such as severe local hemorrhage, nervous system effects and tissue necrosis. Because the three-dimensional (3D) structure of SVMP is not known, models were constructed, and the best model was selected based on its stereo-chemical quality. The stability of the modeled protein was analyzed through molecular dynamics (MD) simulation studies. Structure-based virtual screening was performed, and 15 potential molecules with the highest binding energies were selected. Further analysis was carried out with induced fit docking, Prime/MM-GBSA (ΔGBind calculations), quantum-polarized ligand docking, and density functional theory calculations. Further, the stability of the lead molecules in the SVMP-active site was examined using MD simulation. The results showed that the selected lead molecules were highly stable in the active site of SVMP. Hence, these molecules could potentially be selective inhibitors of SVMP. These lead molecules can be experimentally validated, and their backbone structural scaffold could serve as building blocks in designing drug-like molecules for snake antivenom.

  20. Identification of GPR65, a novel regulator of matrix metalloproteinases using high through-put screening

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Hongbo; Chen, Xiaohong; Huang, Junwei [Department of Otolaryngology-Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Key Laboratory of Otolaryngology Head and Neck Surgery, Beijing (China); Deng, Weiwei [Functional Genomics Group, Chinese National Human Genome Center (CHGB) at Beijing (China); Zhong, Qi [Department of Otolaryngology-Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Key Laboratory of Otolaryngology Head and Neck Surgery, Beijing (China); Yue, Changli [Department of Pathology, Beijing Tongren Hospital, Capital Medical University, Beijing (China); Wang, Pingzhang, E-mail: wangpzh@bjmu.edu.cn [Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Peking University Center for Human Disease Genomics, Key Laboratory of Medical Immunology, Ministry of Health (China); Functional Genomics Group, Chinese National Human Genome Center (CHGB) at Beijing (China); Huang, Zhigang, E-mail: enthuangzhigang@sohu.com [Department of Otolaryngology-Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Key Laboratory of Otolaryngology Head and Neck Surgery, Beijing (China)

    2013-06-21

    Highlights: •A novel mechanism of MMP3 regulation by proton-sensing G-protein-coupled receptors was defined. •GPR65 was identified to induce the MMP3 expression. •GPR65 mediated MMP induction under acidic conditions. •AP-1 binding site in MMP3 promoter was crucial for MMP3 induction. •GPR65 overexpression can accelerate the invision of A549 cells. -- Abstract: Matrix metalloproteinases (MMPs) are over-expressed in nearly all cancers. To study novel regulatory factors of MMP expression in head and neck cancer (HNC), we screened a total of 636 candidate genes encoding putative human transmembrane proteins using MMP promoter reporter in a dual luciferase assay system. Three genes GPR65, AXL and TNFRSF10B dramatically activated the induction of MMP3 expression. The induction of MMP expression by GPR65 was further confirmed in A549 and/or FaDu cells. GPR65 mediated MMP induction under acidic conditions. The AP-1 binding site in MMP3 promoter was crucial for MMP3 induction. Moreover, the A549 cells infected by recombinant adenovirus of GPR65 showed accelerated cell invasion. In conclusion, we validate that GPR65 is vital regulatory genes upstream of MMP3, and define a novel mechanism of MMP3 regulation by proton-sensing G-protein-coupled receptors.

  1. Identification of GPR65, a novel regulator of matrix metalloproteinases using high through-put screening

    International Nuclear Information System (INIS)

    Xu, Hongbo; Chen, Xiaohong; Huang, Junwei; Deng, Weiwei; Zhong, Qi; Yue, Changli; Wang, Pingzhang; Huang, Zhigang

    2013-01-01

    Highlights: •A novel mechanism of MMP3 regulation by proton-sensing G-protein-coupled receptors was defined. •GPR65 was identified to induce the MMP3 expression. •GPR65 mediated MMP induction under acidic conditions. •AP-1 binding site in MMP3 promoter was crucial for MMP3 induction. •GPR65 overexpression can accelerate the invision of A549 cells. -- Abstract: Matrix metalloproteinases (MMPs) are over-expressed in nearly all cancers. To study novel regulatory factors of MMP expression in head and neck cancer (HNC), we screened a total of 636 candidate genes encoding putative human transmembrane proteins using MMP promoter reporter in a dual luciferase assay system. Three genes GPR65, AXL and TNFRSF10B dramatically activated the induction of MMP3 expression. The induction of MMP expression by GPR65 was further confirmed in A549 and/or FaDu cells. GPR65 mediated MMP induction under acidic conditions. The AP-1 binding site in MMP3 promoter was crucial for MMP3 induction. Moreover, the A549 cells infected by recombinant adenovirus of GPR65 showed accelerated cell invasion. In conclusion, we validate that GPR65 is vital regulatory genes upstream of MMP3, and define a novel mechanism of MMP3 regulation by proton-sensing G-protein-coupled receptors

  2. Immunohistochemical correlation of matrix metalloproteinase-2 and tissue inhibitors of metalloproteinase-2 in tobacco associated epithelial dysplasia.

    Science.gov (United States)

    Bajracharya, Dipshikha; Shrestha, Bijayatha; Kamath, Asha; Menon, Aparna; Radhakrishnan, Raghu

    2014-01-01

    To study the immunohistochemical expression of matrix metalloproteinase and tissue inhibitors of matrix metalloproteinase-2 in different histological grades of tobacco associated epithelial dysplasia and correlate the association between these proteases. Potentially malignant oral disorders (PMODs) progressing to oral cancer are related to the severity of epithelial dysplasia. A retrospective immunohistochemical study was carried out on 30 clinically and histologically proven cases of leukoplakia with dysplasia and 10 cases of normal buccal mucosa using anti-MMP-2 and anti-TIMP-2 monoclonal antibodies. Mann Whitney U test, for comparing the expression of both MMP-2 and TIMP-2 in normal mucosa with dysplasia, was highly significant (P correlation between MMP-2 and TIMP-2 through different grades of dysplasia and cells observed showed positive correlation. Concomitant increase in the expression of both MMP-2 and TIMP-2 suggested that the activation of MMP-2 is dependent on TIMP-2 acting as a cofactor. Changes in TIMP-2 levels are considered important because they directly affect the level of MMP-2 activity.

  3. Relationship between Serum Levels of Metalloproteinase-8 and Tissue Inhibitor of Metalloproteinases-1 and Exercise Test Results in Postmenopausal Women

    Directory of Open Access Journals (Sweden)

    J. Mieczkowska

    2016-01-01

    Full Text Available Physical activity as a part of the lifestyle is a significant factor influencing health condition. Exercises that require stamina are of particular importance. Oxygen metabolism, which is a significant part of all longer training processes, has an influence on cardiovascular and respiratory system functioning as well as all the processes taking part in maintenance of efficient homeostasis. Presentation of the correlation between exercise test results and MMP-8 (metalloproteinase-8 and TIMP-1 (tissue inhibitor of metalloproteinases-1 levels was attempted in this work. MMP-8 is a proteolytic enzyme taking part in progression of diseases related to process of ageing. 62 healthy women in postmenopausal period were qualified for the study (mean age: 54±3.6. There was exercise test on the treadmill according to Bruce’s protocol performed. MMP-8 and TIMP-1 serum levels were measured. There was statistically important correlation between increased level of MMP-8 and increased level of TIMP-1 with lower results of exercise test observed. The conducted study provides further biochemical arguments for prophylactic role of physical activity, which lowers the risk of noninfectious diseases, typical for middle adulthood, by influencing physical capacity.

  4. Fractional Excretion of Survivin, Extracellular Matrix Metalloproteinase Inducer, and Matrix Metalloproteinase 7 in Children with Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Agnieszka Bargenda

    2016-07-01

    Full Text Available Background: Epithelial–mesenchymal transition (EMT is defined as a transformation of tubular epithelial cells into mesenchymal ones. These cells migrate through the extracellular matrix and change into active myofibroblasts, which are responsible for excessive matrix deposition. Such changes may lead to tubular dysfunction and fibrosis of the renal parenchyma, characteristic of chronic kidney disease (CKD. However, there are no data on potential EMT markers in children with CKD. The aim of our study was to assess the usefulness of fractional excretion (FE of survivin, E-cadherin, extracellular matrix metalloproteinase inducer (EMMPRIN, matrix metalloproteinase (MMP7, and transforming growth factor beta 1 (TGF-β1 as potential markers of CKD-related complications such as tubular damage and fibrosis. Methods: Forty-one pre-dialysis children with CKD Stages 3–5 and 23 age-matched controls were enrolled in the study. The serum and urine concentrations of analysed parameters were assessed by an enzyme-linked immunosorbent assay test. Results: Tubular reabsorption of all analysed parameters was >99% in the control group. All FE values rose significantly in children with CKD, yet they remained 1%. Conclusions: FE of the examined markers may become a useful tool in the assessment of tubular dysfunction during the course of CKD. The FE of survivin, EMMPRIN, and MMP7 warrant further research as potential independent markers of kidney-specific EMT.

  5. Epigallocatechin-3-gallate ameliorates intrahepatic cholestasis of pregnancy by inhibiting matrix metalloproteinase-2 and matrix metalloproteinase-9.

    Science.gov (United States)

    Zhang, Mei; Xu, Meimei

    2017-10-01

    Matrix metalloproteinase (MMP)-2 and matrix metalloproteinase-9 are involved in many illnesses affecting pregnant women, including intrahepatic cholestasis of pregnancy (ICP), a serious liver abnormality during pregnancy. Epigallocatechin-3-gallate (EGCG) has been widely reported to inhibit activities of MMP-2 and MMP-9. We aimed to investigate the role of EGCG in ameliorating ICP symptoms in a rat model. Using 17α-ethinylestradiol to induce ICP in pregnant rats, we investigated the efficacy of EGCG administration on ICP symptoms, including bile flow rate, total bile acids (TBA) and MMP-2 and MMP-9 activities. Correlation study was conducted among levels of the two MMPs with other ICP symptoms. In ICP rats, activities of both MMP-2 and MMP-9 were significantly elevated. EGCG administration could inhibit the upregulation of MMP-2 and MMP-9 post-transcriptionally. Furthermore, EGCG ameliorated ICP symptoms, as evidenced by restored bile flow rate and TBA, showing efficient treatment outcomes. At last, levels of TBA and the two MMPs were found to be strongly correlated. Our study demonstrates that, for the first time, the efficacy of EGCG in ameliorating ICP symptoms by inhibiting both MMP-2 and MMP-9, which supports its potential as a novel drug in ameliorating ICP. © 2017 Société Française de Pharmacologie et de Thérapeutique.

  6. Immunohistochemical Correlation of Matrix Metalloproteinase-2 and Tissue Inhibitors of Metalloproteinase-2 in Tobacco Associated Epithelial Dysplasia

    Directory of Open Access Journals (Sweden)

    Dipshikha Bajracharya

    2014-01-01

    Full Text Available Aim. To study the immunohistochemical expression of matrix metalloproteinase and tissue inhibitors of matrix metalloproteinase-2 in different histological grades of tobacco associated epithelial dysplasia and correlate the association between these proteases. Potentially malignant oral disorders (PMODs progressing to oral cancer are related to the severity of epithelial dysplasia. Methods. A retrospective immunohistochemical study was carried out on 30 clinically and histologically proven cases of leukoplakia with dysplasia and 10 cases of normal buccal mucosa using anti-MMP-2 and anti-TIMP-2 monoclonal antibodies. Results. Mann Whitney U test, for comparing the expression of both MMP-2 and TIMP-2 in normal mucosa with dysplasia, was highly significant (P<0.001. Kruskal-Wallis test to compare the median score of MMP-2 and TIMP-2 in different grades of dysplasia showed statistical significance (P<0.001, and a Spearman’s correlation between MMP-2 and TIMP-2 through different grades of dysplasia and cells observed showed positive correlation. Conclusion. Concomitant increase in the expression of both MMP-2 and TIMP-2 suggested that the activation of MMP-2 is dependent on TIMP-2 acting as a cofactor. Changes in TIMP-2 levels are considered important because they directly affect the level of MMP-2 activity.

  7. Essential Structural and Functional Roles of the Cmr4 Subunit in RNA Cleavage by the Cmr CRISPR-Cas Complex

    Directory of Open Access Journals (Sweden)

    Nancy F. Ramia

    2014-12-01

    Full Text Available Summary: The Cmr complex is the multisubunit effector complex of the type III-B clustered regularly interspaced short palindromic repeats (CRISPR-Cas immune system. The Cmr complex recognizes a target RNA through base pairing with the integral CRISPR RNA (crRNA and cleaves the target at multiple regularly spaced locations within the complementary region. To understand the molecular basis of the function of this complex, we have assembled information from electron microscopic and X-ray crystallographic structural studies and mutagenesis of a complete Pyrococcus furiosus Cmr complex. Our findings reveal that four helically packed Cmr4 subunits, which make up the backbone of the Cmr complex, act as a platform to support crRNA binding and target RNA cleavage. Interestingly, we found a hook-like structural feature associated with Cmr4 that is likely the site of target RNA binding and cleavage. Our results also elucidate analogies in the mechanisms of crRNA and target molecule binding by the distinct Cmr type III-A and Cascade type I-E complexes. : Ramia et al. show that the helical core of the type III-B Cmr CRISPR-Cas effector complex, made up of multiple Cmr4 subunits, forms the platform for a corresponding number of cleavages of the target RNA. Comparison with the type I-E Cascade structure reveals strikingly similar mechanisms of crRNA and target binding.

  8. Targeted cleavage of hepatitis E virus 3' end RNA mediated by hammerhead ribozymes inhibits viral RNA replication

    International Nuclear Information System (INIS)

    Sriram, Bandi; Thakral, Deepshi; Panda, Subrat Kumar

    2003-01-01

    The 3' end of hepatitis E virus (HEV) contains cis-acting regulatory element, which plays an important role in viral replication. To develop specific replication inhibitor at the molecular level, mono- and di-hammerhead ribozymes (Rz) were designed and synthesized against the conserved 3' end sequences of HEV, which cleave at nucleotide positions 7125 and 7112/7125, respectively. Di-hammerhead ribozyme with two catalytic motifs in tandem was designed to cleave simultaneously at two sites spaced 13 nucleotides apart, which increases the overall cleavage efficiency and prevents the development of escape mutants. Specific cleavage products were obtained with both the ribozymes in vitro at physiological conditions. The inactive control ribozymes showed no cleavage. The ribozymes showed specific inhibition of HEV 3' end fused-luciferase reporter gene expression by ∼37 and ∼60%, respectively in HepG2 cells. These results demonstrate a feasible approach to inhibit the HEV replication to a limited extent by targeting the cis-acting 3' end of HEV with hammerhead ribozymes

  9. In vitro measurement of beta-carotene cleavage activity : methodological considerations and the effect of other carotenoids on beta-carotene cleavage

    NARCIS (Netherlands)

    Vliet, T. van; Schaik, F. van; Schreurs, W.H.P.; Berg, H. van den

    1996-01-01

    In view of controversies about assessment of the β-carotene cleavage activity, methodological aspects and problems of the dioxygenase assay are described. Using rat and hamster intestinal preparations the method was optimized on retinal formation, the only cleavage product we could demonstrate. It

  10. The Conformational Dynamics of Cas9 Governing DNA Cleavage Are Revealed by Single-Molecule FRET

    Directory of Open Access Journals (Sweden)

    Mengyi Yang

    2018-01-01

    Full Text Available Summary: Off-target binding and cleavage by Cas9 pose major challenges in its application. How the conformational dynamics of Cas9 govern its nuclease activity under on- and off-target conditions remains largely unknown. Here, using intra-molecular single-molecule fluorescence resonance energy transfer measurements, we revealed that Cas9 in apo, sgRNA-bound, and dsDNA/sgRNA-bound forms spontaneously transits among three major conformational states, mainly reflecting significant conformational mobility of the catalytic HNH domain. We also uncovered surprising long-range allosteric communication between the HNH domain and the RNA/DNA heteroduplex at the PAM-distal end to ensure correct positioning of the catalytic site, which demonstrated that a unique proofreading mechanism served as the last checkpoint before DNA cleavage. Several Cas9 residues were likely to mediate the allosteric communication and proofreading step. Modulating interactions between Cas9 and heteroduplex at the PAM-distal end by introducing mutations on these sites provides an alternative route to improve and optimize the CRISPR/Cas9 toolbox. : Yang et al. revealed significant conformational dynamics of Cas9 at global and local scales using single-molecule FRET. They uncovered surprising long-range allosteric communication between the HNH nuclease domain and the RNA/DNA heteroduplex at the PAM-distal end that serves as a proofreading checkpoint to govern the nuclease activity and specificity of Cas9. Keywords: CRISPR, Cas9, single-molecule, FRET, conformational dynamics, proofreading, off-target, allosteric communication, genome editing

  11. Autolysis at the disintegrin domain of patagonfibrase, a metalloproteinase from Philodryas patagoniensis (Patagonia Green Racer; Dipsadidae) venom.

    Science.gov (United States)

    Peichoto, María E; Paes Leme, Adriana F; Pauletti, Bianca A; Batista, Isabel Correia; Mackessy, Stephen P; Acosta, Ofelia; Santoro, Marcelo L

    2010-09-01

    Patagonfibrase is a 57.5-kDa hemorrhagic metalloproteinase isolated from the venom of Philodryas patagoniensis (Patagonia Green Racer), a South American rear-fanged snake. Herein we demonstrate that patagonfibrase undergoes autolysis at its pH optimum (7.5) and at 37 degrees C, primarily producing a approximately 32.6 kDa fragment composed of disintegrin-like and cysteine-rich domains, as identified by mass spectrometry and N-terminal sequencing. The autolysis site for production of this fragment is similar to that observed for metalloproteinases from front-fanged Viperidae snake venoms. In the presence of Ca(2+), patagonfibrase was only partially autolysed, giving rise mainly to one fragment of approximately 52.2 kDa. In addition, calcium markedly enhanced the azocaseinolytic activity of patagonfibrase. Our findings contribute to the understanding of the structural and mechanistic bases of this family of metalloenzymes that are widely distributed among snake venoms, demonstrating that important post-translational modifications such as proteolysis can also contribute to the diversity and complexity of proteins found in rear-fanged snake venoms. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. Overexpression of membrane sialic acid-specific sialidase Neu3 inhibits matrix metalloproteinase-9 expression in vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Moon, Sung-Kwon; Cho, Seung-Hak; Kim, Kyung-Woon; Jeon, Jae Heung; Ko, Jeong-Heon; Kim, Bo Yeon; Kim, Cheorl-Ho

    2007-01-01

    The ganglioside-specific sialidase Neu3 has been suggested to participate in cell growth, migration, and differentiation. Recent reports suggest that sialidase may be involved in intimal thickening, an early stage in the development of atherosclerosis. However, the role of the Neu3 gene in vascular smooth muscle cells (VSMC) responses has not yet been elucidated. To determine whether a Neu3 is able to modulate VSMC growth, the effect of overexpression of the Neu3 gene on cell proliferation was examined. However, the results show that the overexpression of this gene has no effect on DNA synthesis and ERK phosphorylation in cultured VSMC in the presence of TNF-α. Because atherogenic effects need not be limited to proliferation, we decided to examine whether Neu3 exerted inhibitory effects on matrix metalloproteinase-9 (MMP-9) activity in TNF-α-induced VSMC. The expression of the Neu3 gene led to the inhibition of TNF-α-induced matrix metalloproteinase-9 (MMP-9) expression in VSMC as determined by zymography and immunoblot. Furthermore, Neu3 gene expression strongly decreased MMP-9 promoter activity in response to TNF-α. This inhibition was characterized by the down-regulation of MMP-9, which was transcriptionally regulated at NF-κB and activation protein-1 (AP-1) sites in the MMP-9 promoter. These findings suggest that the Neu3 gene represents a physiological modulator of VSMC responses that may contribute to plaque instability in atherosclerosis

  13. Delayed-type hypersensitivity lesions in the central nervous system are prevented by inhibitors of matrix metalloproteinases.

    Science.gov (United States)

    Matyszak, M K; Perry, V H

    1996-09-01

    We have studied the effect of an inhibitor of matrix metalloproleinases, BB-1101, on a delayed-type hypersensitivity (DTH) response in the CNS. We used a recently described model in which heat-killed bacillus Calmette-Guérin (BCG) sequestered behind the blood-brain barrier (BBB) is targeted by a T-cell mediated response after subcutaneous injection of BCG (Matyszak and Perry, 1995). The DTH lesions are characterised by breakdown of the BBB, macrophage and lymphocyte infiltration and tissue damage including myelin loss. Treatment with BB-1101, which is not only a potent inhibitor of matrix metalloproteinases but also strongly inhibits TNF-alpha release, dramatically attenuated the CNS lesions. Breakdown of the BBB and the recruitment of T-cells into the site of the lesion were significantly reduced. There were many fewer inflammatory macrophages in DTH lesions than in comparable lesions from untreated animals. There was also significantly less myelin damage (assessed by staining with anti-MBP antibody). The DTH response in animals treated with dexamethasone was also reduced, but to a lesser degree. No significant effect was seen after administration of pentoxifylline, a phosphodiesterase inhibitor with effects including the inhibition of TNF-alpha production. Our results suggest that inhibitors of matrix metalloproteinases may be of considerable therapeutic benefit in neuroinflammatory diseases.

  14. The extracellular matrix metalloproteinase inducer EMMPRIN is a target of nitric oxide in myocardial ischemia/reperfusion.

    Science.gov (United States)

    Tarin, Carlos; Lavin, Begoña; Gomez, Monica; Saura, Marta; Diez-Juan, Antonio; Zaragoza, Carlos

    2011-07-15

    Nitric oxide (NO) is an important defense against myocardial ischemia/reperfusion (I/R) injury. Although matrix metalloproteinase (MMP)-mediated necrosis of cardiac myocytes is well characterized, the role of inducible NO synthase (iNOS)-derived NO in this process is poorly understood. I/R injury was increased in iNOS-deficient mice and in mice treated with 1400 W (a pharmacological iNOS inhibitor) and was associated with significantly increased expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and EMMPRIN-associated MMPs. Transcriptional activity of an EMMPRIN luciferase promoter reporter expressed in cardiac myocytes was inhibited by NO in a cGMP-dependent manner, and this transcriptional inhibition was abolished by mutation of a putative E2F site. Consistent with these findings, EMMPRIN null mice, in which iNOS is normally induced, are partially protected against I/R injury. Pharmacological inhibition of iNOS in EMMPRIN null mice had no additional protective effect, suggesting that EMMPRIN is a downstream target of NO. Administration of anti-EMMPRIN neutralizing antibodies partly reduced the excess heart damage and MMP-9 expression induced by I/R in iNOS null mice, indicating that regulation of EMMPRIN is an important mechanism of NO-mediated cardioprotection. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Carotenoid-cleavage activities of crude enzymes from Pandanous amryllifolius.

    Science.gov (United States)

    Ningrum, Andriati; Schreiner, Matthias

    2014-11-01

    Carotenoid degradation products, known as norisoprenoids, are aroma-impact compounds in several plants. Pandan wangi is a common name of the shrub Pandanus amaryllifolius. The genus name 'Pandanus' is derived from the Indonesian name of the tree, pandan. In Indonesia, the leaves from the plant are used for several purposes, e.g., as natural colorants and flavor, and as traditional treatments. The aim of this study was to determine the cleavage of β-carotene and β-apo-8'-carotenal by carotenoid-cleavage enzymes isolated from pandan leaves, to investigate dependencies of the enzymatic activities on temperature and pH, to determine the enzymatic reaction products by using Headspace Solid Phase Microextraction Gas Chromatography/Mass Spectrophotometry (HS-SPME GC/MS), and to investigate the influence of heat treatment and addition of crude enzyme on formation of norisoprenoids. Crude enzymes from pandan leaves showed higher activity against β-carotene than β-apo-8'-carotenal. The optimum temperature of crude enzymes was 70°, while the optimum pH value was 6. We identified β-ionone as the major volatile reaction product from the incubations of two different carotenoid substrates, β-carotene and β-apo-8'-carotenal. Several treatments, e.g., heat treatment and addition of crude enzymes in pandan leaves contributed to the norisoprenoid content. Our findings revealed that the crude enzymes from pandan leaves with carotenoid-cleavage activity might provide a potential application, especially for biocatalysis, in natural-flavor industry. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

  16. High cleavage efficiency of a 2A peptide derived from porcine teschovirus-1 in human cell lines, zebrafish and mice.

    Directory of Open Access Journals (Sweden)

    Jin Hee Kim

    Full Text Available When expression of more than one gene is required in cells, bicistronic or multicistronic expression vectors have been used. Among various strategies employed to construct bicistronic or multicistronic vectors, an internal ribosomal entry site (IRES has been widely used. Due to the large size and difference in expression levels between genes before and after IRES, however, a new strategy was required to replace IRES. A self-cleaving 2A peptide could be a good candidate to replace IRES because of its small size and high cleavage efficiency between genes upstream and downstream of the 2A peptide. Despite the advantages of the 2A peptides, its use is not widespread because (i there are no publicly available cloning vectors harboring a 2A peptide gene and (ii comprehensive comparison of cleavage efficiency among various 2A peptides reported to date has not been performed in different contexts. Here, we generated four expression plasmids each harboring different 2A peptides derived from the foot-and-mouth disease virus, equine rhinitis A virus, Thosea asigna virus and porcine teschovirus-1, respectively, and evaluated their cleavage efficiency in three commonly used human cell lines, zebrafish embryos and adult mice. Western blotting and confocal microscopic analyses revealed that among the four 2As, the one derived from porcine teschovirus-1 (P2A has the highest cleavage efficiency in all the contexts examined. We anticipate that the 2A-harboring cloning vectors we generated and the highest efficiency of the P2A peptide we demonstrated would help biomedical researchers easily adopt the 2A technology when bicistronic or multicistronic expression is required.

  17. Activity of matrix metalloproteinases during antimycobacterial therapy in mice with simulated tuberculous inflammation.

    Science.gov (United States)

    Sumenkova, D V; Russkikh, G S; Poteryaeva, O N; Polyakov, L M; Panin, L E

    2013-05-01

    Matrix metalloproteinases are shown to be involved in the pathogenesis of tuberculosis inflammation. In the early stages of BCG-granuloma formation in mouse liver and lungs, the serum levels of matrix metalloproteinases 2 and 7 increased by 4.5 times and remained unchanged while the pathology developed. Antimycobacterial therapy with isoniazid reduced enzyme activity almost to the level of intact control. The decrease in activity of matrix metalloproteinases 2 and 7 that play the most prominent role in the development of destructive forms of tuberculosis is of great therapeutic importance.

  18. Collagenolytic Matrix Metalloproteinases in Chronic Obstructive Lung Disease and Cancer

    Directory of Open Access Journals (Sweden)

    Denzel Woode

    2015-02-01

    Full Text Available Chronic obstructive pulmonary disease (COPD and lung cancer result in significant morbidity and mortality worldwide. In addition to the role of environmental smoke exposure in the development of both diseases, recent epidemiological studies suggests a connection between the development of COPD and lung cancer. Furthermore, individuals with concomitant COPD and cancer have a poor prognosis when compared with individuals with lung cancer alone. The modulation of molecular pathways activated during emphysema likely lead to an increased susceptibility to lung tumor growth and metastasis. This review summarizes what is known in the literature examining the molecular pathways affecting matrix metalloproteinases (MMPs in this process as well as external factors such as smoke exposure that have an impact on tumor growth and metastasis. Increased expression of MMPs provides a unifying link between lung cancer and COPD.

  19. Collagenolytic Matrix Metalloproteinases in Chronic Obstructive Lung Disease and Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Woode, Denzel; Shiomi, Takayuki; D’Armiento, Jeanine, E-mail: jmd12@cumc.columbia.edu [Department of Anesthesiology, Columbia University, College of Physicians and Surgeons, New York, NY 10033 (United States)

    2015-02-05

    Chronic obstructive pulmonary disease (COPD) and lung cancer result in significant morbidity and mortality worldwide. In addition to the role of environmental smoke exposure in the development of both diseases, recent epidemiological studies suggests a connection between the development of COPD and lung cancer. Furthermore, individuals with concomitant COPD and cancer have a poor prognosis when compared with individuals with lung cancer alone. The modulation of molecular pathways activated during emphysema likely lead to an increased susceptibility to lung tumor growth and metastasis. This review summarizes what is known in the literature examining the molecular pathways affecting matrix metalloproteinases (MMPs) in this process as well as external factors such as smoke exposure that have an impact on tumor growth and metastasis. Increased expression of MMPs provides a unifying link between lung cancer and COPD.

  20. New Insights into the Role of Matrix Metalloproteinases in Preeclampsia.

    Science.gov (United States)

    Espino Y Sosa, Salvador; Flores-Pliego, Arturo; Espejel-Nuñez, Aurora; Medina-Bastidas, Diana; Vadillo-Ortega, Felipe; Zaga-Clavellina, Veronica; Estrada-Gutierrez, Guadalupe

    2017-07-20

    Preeclampsia is a severe pregnancy complication globally, characterized by poor placentation triggering vascular dysfunction. Matrix metalloproteinases (MMPs) exhibit proteolytic activity implicated in the efficiency of trophoblast invasion to the uterine wall, and a dysregulation of these enzymes has been linked to preeclampsia. A decrease in MMP-2 and MMP-9 interferes with the normal remodeling of spiral arteries at early pregnancy stages, leading to the initial pathophysiological changes observed in preeclampsia. Later in pregnancy, an elevation in MMP-2 and MMP-9 induces abnormal release of vasoactive factors conditioning hypertension. Although these two enzymes lead the scene, other MMPs like MMP-1 and MMP-14 seem to have a role in this pathology. This review gathers published recent evidence about the implications of different MMPs in preeclampsia, and the potential use of these enzymes as emergent biomarkers and biological therapeutic targets, focusing on studies involving human subjects.

  1. Collagenolytic Matrix Metalloproteinases in Chronic Obstructive Lung Disease and Cancer

    International Nuclear Information System (INIS)

    Woode, Denzel; Shiomi, Takayuki; D’Armiento, Jeanine

    2015-01-01

    Chronic obstructive pulmonary disease (COPD) and lung cancer result in significant morbidity and mortality worldwide. In addition to the role of environmental smoke exposure in the development of both diseases, recent epidemiological studies suggests a connection between the development of COPD and lung cancer. Furthermore, individuals with concomitant COPD and cancer have a poor prognosis when compared with individuals with lung cancer alone. The modulation of molecular pathways activated during emphysema likely lead to an increased susceptibility to lung tumor growth and metastasis. This review summarizes what is known in the literature examining the molecular pathways affecting matrix metalloproteinases (MMPs) in this process as well as external factors such as smoke exposure that have an impact on tumor growth and metastasis. Increased expression of MMPs provides a unifying link between lung cancer and COPD

  2. Neuronal matrix metalloproteinase-9 is a determinant of selective neurodegeneration.

    Science.gov (United States)

    Kaplan, Artem; Spiller, Krista J; Towne, Christopher; Kanning, Kevin C; Choe, Ginn T; Geber, Adam; Akay, Turgay; Aebischer, Patrick; Henderson, Christopher E

    2014-01-22

    Selective neuronal loss is the hallmark of neurodegenerative diseases. In patients with amyotrophic lateral sclerosis (ALS), most motor neurons die but those innervating extraocular, pelvic sphincter, and slow limb muscles exhibit selective resistance. We identified 18 genes that show >10-fold differential expression between resistant and vulnerable motor neurons. One of these, matrix metalloproteinase-9 (MMP-9), is expressed only by fast motor neurons, which are selectively vulnerable. In ALS model mice expressing mutant superoxide dismutase (SOD1), reduction of MMP-9 function using gene ablation, viral gene therapy, or pharmacological inhibition significantly delayed muscle denervation. In the presence of mutant SOD1, MMP-9 expressed by fast motor neurons themselves enhances activation of ER stress and is sufficient to trigger axonal die-back. These findings define MMP-9 as a candidate therapeutic target for ALS. The molecular basis of neuronal diversity thus provides significant insights into mechanisms of selective vulnerability to neurodegeneration. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. New Insights into the Role of Matrix Metalloproteinases in Preeclampsia

    Directory of Open Access Journals (Sweden)

    Salvador Espino Y. Sosa

    2017-07-01

    Full Text Available Preeclampsia is a severe pregnancy complication globally, characterized by poor placentation triggering vascular dysfunction. Matrix metalloproteinases (MMPs exhibit proteolytic activity implicated in the efficiency of trophoblast invasion to the uterine wall, and a dysregulation of these enzymes has been linked to preeclampsia. A decrease in MMP-2 and MMP-9 interferes with the normal remodeling of spiral arteries at early pregnancy stages, leading to the initial pathophysiological changes observed in preeclampsia. Later in pregnancy, an elevation in MMP-2 and MMP-9 induces abnormal release of vasoactive factors conditioning hypertension. Although these two enzymes lead the scene, other MMPs like MMP-1 and MMP-14 seem to have a role in this pathology. This review gathers published recent evidence about the implications of different MMPs in preeclampsia, and the potential use of these enzymes as emergent biomarkers and biological therapeutic targets, focusing on studies involving human subjects.

  4. Tissue inhibitor of metalloproteinases-1 in breast cancer

    DEFF Research Database (Denmark)

    Würtz, Sidse Ørnbjerg; Rasmussen, Anne-Sofie Schrohl; Sørensen, Nanna Møller

    2005-01-01

    Whether patients diagnosed with primary breast cancer are offered adjuvant systemic therapy following surgical removal of the tumor is based on prognosis. Prognosis is estimated in every patient using established prognostic variables. Unfortunately, when using the currently available prognostic...... parameters a significant proportion of patients are over-treated. Thus, in order to improve stratification of breast cancer patients, additional prognostic factors need to be identified. Tissue inhibitor of metalloproteinases-1 (TIMP-1) is one of the promising candidates for new prognostic markers in breast...... cancer, as a number of studies have demonstrated an association between high tumor-tissue levels of TIMP-1 mRNA as well as TIMP-1 protein and a poor prognosis of breast cancer patients. TIMP-1 is a member of the TIMP family, currently comprising four members (TIMP-1-4), and its main function...

  5. Matrix metalloproteinase-2 gene variants and abdominal aortic aneurysm.

    Science.gov (United States)

    Smallwood, L; Warrington, N; Allcock, R; van Bockxmeer, F; Palmer, L J; Iacopetta, B; Golledge, J; Norman, P E

    2009-08-01

    To investigate associations between two polymorphisms of the matrix metalloproteinase-2 gene (MMP2) and the incidence and progression of abdominal aortic aneurysm (AAA). Cases and controls were recruited from a trial of screening for AAAs. The association between two variants of MMP2 (-1360C>T, and +649C>T) in men with AAA (n=678) and in controls (n=659) was examined using multivariate analyses. The association with AAA expansion (n=638) was also assessed. In multivariate analyses with adjustments for multiple testing, no association between either SNP and AAA presence or expansion was detected. MMP2 -1360C>T and +649C>T variants are not risk factors for AAA.

  6. Structural and functional characterization of cleavage and inactivation of human serine protease inhibitors by the bacterial SPATE protease EspPα from enterohemorrhagic E. coli.

    Directory of Open Access Journals (Sweden)

    André Weiss

    Full Text Available EspPα and EspI are serine protease autotransporters found in enterohemorrhagic Escherichia coli. They both belong to the SPATE autotransporter family and are believed to contribute to pathogenicity via proteolytic cleavage and inactivation of different key host proteins during infection. Here, we describe the specific cleavage and functional inactivation of serine protease inhibitors (serpins by EspPα and compare this activity with the related SPATE EspI. Serpins are structurally related proteins that regulate vital protease cascades, such as blood coagulation and inflammatory host response. For the rapid determination of serpin cleavage sites, we applied direct MALDI-TOF-MS or ESI-FTMS analysis of coincubations of serpins and SPATE proteases and confirmed observed cleavage positions using in-gel-digest of SDS-PAGE-separated degradation products. Activities of both serpin and SPATE protease were assessed in a newly developed photometrical assay using chromogenic peptide substrates. EspPα cleaved the serpins α1-protease inhibitor (α1-PI, α1-antichymotrypsin, angiotensinogen, and α2-antiplasmin. Serpin cleavage led to loss of inhibitory function as demonstrated for α1-PI while EspPα activity was not affected. Notably, EspPα showed pronounced specificity and cleaved procoagulatory serpins such as α2-antiplasmin while the anticoagulatory antithrombin III was not affected. Together with recently published research, this underlines the interference of EspPα with hemostasis or inflammatory responses during infection, while the observed interaction of EspI with serpins is likely to be not physiologically relevant. EspPα-mediated serpin cleavage occurred always in flexible loops, indicating that this structural motif might be required for substrate recognition.

  7. The Metalloproteinase ADAM28 Promotes Metabolic Dysfunction in Mice

    Directory of Open Access Journals (Sweden)

    Lakshini Herat

    2017-04-01

    Full Text Available Obesity and diabetes are major causes of morbidity and mortality globally. The current study builds upon our previous association studies highlighting that A Disintegrin And Metalloproteinase 28 (ADAM28 appears to be implicated in the pathogenesis of obesity and type 2 diabetes in humans. Our novel study characterised the expression of ADAM28 in mice with the metabolic syndrome and used molecular inhibition approaches to investigate the functional role of ADAM28 in the pathogenesis of high fat diet-induced obesity. We identified that ADAM28 mRNA and protein expression was markedly increased in the livers of mice with the metabolic syndrome. In addition, noradrenaline, the major neurotransmitter of the sympathetic nervous system, results in elevated Adam28 mRNA expression in human monocytes. Downregulation of ADAM28 with siRNA technology resulted in a lack of weight gain, promotion of insulin sensitivity/glucose tolerance and decreased liver tumour necrosis factor-α (TNF-α levels in our diet-induced obesity mouse model as well as reduced blood urea nitrogen, alkaline phosphatase and aspartate aminotransferase. In addition, we show that ADAM28 knock-out mice also displayed reduced body weight, elevated high density lipoprotein cholesterol levels, and reductions in blood urea nitrogen, alkaline phosphatase, and aspartate aminotransferase. The results of this study provide important insights into the pathogenic role of the metalloproteinase ADAM28 in the metabolic syndrome and suggests that downregulation of ADAM28 may be a potential therapeutic strategy in the metabolic syndrome.

  8. CDP-choline modulates matrix metalloproteinases in rat sciatic injury.

    Science.gov (United States)

    Gundogdu, Elif Basaran; Bekar, Ahmet; Turkyilmaz, Mesut; Gumus, Abdullah; Kafa, Ilker Mustafa; Cansev, Mehmet

    2016-02-01

    CDP-choline (cytidine-5'-diphosphocholine) improves functional recovery, promotes nerve regeneration, and decreases perineural scarring in rat peripheral nerve injury. The aim of the present study was to investigate the mechanism of action of CDP-choline with regard to matrix metalloproteinase (MMP) activity in the rat-transected sciatic nerve injury model. Male Wistar rats were randomized into Sham, Saline, and CDP-choline groups. Rats in Sham group received Sham surgery, whereas rats in Saline and CDP-choline groups underwent right sciatic nerve transection followed by immediate primary saturation and injected intraperitoneally with 0.9% NaCl (1 mL/kg) and CDP-choline (600 μg/kg), respectively. Sciatic nerve samples were obtained 1, 3, and 7 d after the surgery and analyzed for levels and activities of MMP-2 and MMP-9, levels of tissue inhibitor of metalloproteinases-1 (TIMP-1) and TIMP-3, and axonal regeneration. CDP-choline treatment decreased the levels and activities of MMP-2 and MMP-9, whereas increasing levels of TIMP-1 and TIMP-3 significantly on the third and seventh day after injury compared to Saline group. In addition, CDP-choline administration resulted in new axon formation and formation and advancement of myelination on newly formed islets (compartments) of axonal regrowth. Our data show, for the first time, that CDP-choline modulates MMP activity and promotes the expression of TIMPs to stimulate axonal regeneration. These data help to explain one mechanism by which CDP-choline provides neuroprotection in peripheral nerve injury. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Caspase-2 cleavage of tau reversibly impairs memory.

    Science.gov (United States)

    Zhao, Xiaohui; Kotilinek, Linda A; Smith, Benjamin; Hlynialuk, Chris; Zahs, Kathleen; Ramsden, Martin; Cleary, James; Ashe, Karen H

    2016-11-01

    In Alzheimer's disease (AD) and other tauopathies, the tau protein forms fibrils, which are believed to be neurotoxic. However, fibrillar tau has been dissociated from neuron death and network dysfunction, suggesting the involvement of nonfibrillar species. Here we describe a novel pathological process in which caspase-2 cleavage of tau at Asp314 impairs cognitive and synaptic function in animal and cellular models of tauopathies by promoting the missorting of tau to dendritic spines. The truncation product, Δtau314, resists fibrillation and is present at higher levels in brains from cognitively impaired mice and humans with AD. The expression of tau mutants that resisted caspase-2 cleavage prevented tau from infiltrating spines, dislocating glutamate receptors and impairing synaptic function in cultured neurons, and it prevented memory deficits and neurodegeneration in mice. Decreasing the levels of caspase-2 restored long-term memory in mice that had existing deficits. Our results suggest an overall treatment strategy for re-establishing synaptic function and restoring memory in patients with AD by preventing tau from accumulating in dendritic spines.

  10. Comparison of the cleavage of pyrimidine dimers by the bacteriophage T4 and Micrococcus luteus uv-specific endonucleases

    International Nuclear Information System (INIS)

    Gordon, L.K.; Haseltine, W.A.

    1980-01-01

    A comparison was made of the activity of the uv-specific endonucleases of bacteriophage T4 (T4 endonuclease V) and of Micrococcus luteus on ultraviolet light-irradiated DNA substrates of defined sequence. The two enzyms cleave DNA at the site of pyrimidine dimers with the same frequency. The products of the cleavage reaction are the same. The pyrimidine dimer DNA-glycosylase activity of both enzymes is more active on double-stranded DNA than it is on single-stranded DNA

  11. Altered cleavage patterns in human tripronuclear embryos and their association to fertilization method

    DEFF Research Database (Denmark)

    Joergensen, Mette Warming; Agerholm, Inge; Hindkjaer, Johnny

    2014-01-01

    PURPOSE: To analyze the cleavage patterns in dipronuclear (2PN) and tripronuclear (3PN) embryos in relation to fertilization method. METHOD: Time-lapse analysis. RESULTS: Compared to 2PN, more 3PN IVF embryos displayed early cleavage into 3 cells (p ... stage (p embryos, the 2nd and 3rd cleavage cycles were completed within the expected time frame. However, timing of the cell divisions within the cleavage cycles differed between the two groups. In contrast......, the completion of the 1st, 2nd, and 3rd cleavage cycle was delayed, but with a similar division pattern for 3PN ICSI compared with the 2PN ICSI embryos. 3PN, more often than 2PN ICSI embryos, displayed early cleavage into 3 cells (p = 0.03) and arrested development from the compaction stage and onwards (p = 0...

  12. Cleavage of phosphorothioated DNA and methylated DNA by the type IV restriction endonuclease ScoMcrA.

    Directory of Open Access Journals (Sweden)

    Guang Liu

    2010-12-01

    Full Text Available Many taxonomically diverse prokaryotes enzymatically modify their DNA by replacing a non-bridging oxygen with a sulfur atom at specific sequences. The biological implications of this DNA S-modification (phosphorothioation were unknown. We observed that simultaneous expression of the dndA-E gene cluster from Streptomyces lividans 66, which is responsible for the DNA S-modification, and the putative Streptomyces coelicolor A(32 Type IV methyl-dependent restriction endonuclease ScoA3McrA (Sco4631 leads to cell death in the same host. A His-tagged derivative of ScoA3McrA cleaved S-modified DNA and also Dcm-methylated DNA in vitro near the respective modification sites. Double-strand cleavage occurred 16-28 nucleotides away from the phosphorothioate links. DNase I footprinting demonstrated binding of ScoA3McrA to the Dcm methylation site, but no clear binding could be detected at the S-modified site under cleavage conditions. This is the first report of in vitro endonuclease activity of a McrA homologue and also the first demonstration of an enzyme that specifically cleaves S-modified DNA.

  13. Association of matrix metalloproteinase inducer (EMMPRIN) with the expression of matrix metalloproteinases-1, -2 and -9 during periapical lesion development.

    Science.gov (United States)

    Sousa, Natália Guimarães Kalatzis; Cardoso, Cristina Ribeiro de Barros; Silva, João Satana da; Kuga, Milton Carlos; Tanomaru-Filho, Mário; Faria, Gisele

    2014-09-01

    To evaluate the expression of matrix metalloproteinase inducer (EMMPRIN) and its correlation with the expression of matrix metalloproteinases (MMPs)-1, -2 and -9 during the development of periapical lesion in mice. Periapical lesions were induced in the lower first molars of mice and after 7, 14, 21 and 42 days the mandibles were removed. The periapical lesions were measured by micro-computed tomography. The expression of EMMPRIN, MMPs-1, -2, and -9 genes were determined by real-time RT-PCR. The location and expression of EMMPRIN and MMPs were evaluated by immunohistochemistry. At 14 days, the periapical lesion area was higher than at 7 days. At 21 and 42 days no statistically significant bone loss was observed in comparison to 14 days. The control group showed discrete and occasional EMMPRIM, MMP-1, -2 and -9 immunostaining in the periodontal ligament fibroblasts. At 7, 14, 21 and 42 days intense immunoexpression was observed for EMMPRIN, MMPs-1, -2 and -9 in the region adjacent to the apical foramen. The EMMPRIN immunoexpression was higher at 7, 14, 21 and 42 days compared with the control. There was a positive correlation between gene expression of EMMPRIN and MMPs in the active phase of periapical lesion development. There is a high expression of EMMPRIM mainly by the inflammatory infiltrate in the region adjacent to the apical foramen during periapical lesion development. Furthermore, the positive correlation with MMP-1, -2, and -9 during the first days after periapical lesion induction indicates that EMMPRIM may be involved in the active phase of periapical lesions development. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Serum Matrix Metalloproteinase-9 and Tissue Inhibitor of Metalloproteinase-1 Expression in Patients with Non-alcoholic Fatty Liver Disease

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    Taner Akyol

    2015-06-01

    Full Text Available Non-alcoholic fatty liver disease (NAFLD is the most common chronic liver disease in developed countries. NAFLD may progress to non-alcoholic steatohepatitis (NASH and cirrhosis. Emerging evidence suggests that NAFLD is the hepatic manifestation of metabolic syndrome (MetS. NAFLD is closely linked to MetS, with a significant increase in cardiovascular risk. Several matrix metalloproteinases (MMPs and tissue inhibitors of MMPs (TIMPs play important roles in the pathophysiology of atherosclerosis and liver fibrosis. In this study we investigated the usefulness of serum metalloproteinases as noninvasive markers of NAFLD. Forty-six patients with NAFLD and twenty-six healthy controls were enrolled into the study, in Gulhane Military Medical Academy, Haydarpasa Training Hospital. Liver biopsies were performed on all patients with NAFLD and histopathological evaluations were made by an experienced pathologist. All NAFLD patients were divided into 2 subgroups according to MetS status using ATP III criteria. MMP-9 and TIMP-1 were studied in serum samples of all groups. Results were compared between both groups and subgroups. In this study, the NAFLD and control groups did not differ significantly on MMP-9, TIMP-1 and TIMP-1/MMP-9 ratio (p > 0.05. However, we found a significant relationship between the HOMA and TIMP-1 (p<0.05. Moreover, MMP-9 and TIMP-1/MMP-9 levels were significantly correlated with waist circumference (p<0.05. Our findings are not sufficient to suggest that MMP-9, TIMP-1 and TIMP-1/MMP-9 ratio might be used as noninvasive biochemical diagnostic tests among NAFLD patients. [Dis Mol Med 2015; 3(2.000: 11-17

  15. Liposome-mediated amplified detection of cell-secreted matrix metalloproteinase-9†

    Science.gov (United States)

    Banerjee, Jayati; Hanson, Andrea J.; Nyren-Erickson, Erin K.; Ganguli, Bratati; Wagh, Anil; Muhonen, Wallace W.; Law, Benedict; Shabb, John B.; Srivastava, D. K.; Mallik, Sanku

    2018-01-01

    A liposome-based amplified detection system is presented for the cancer cell secreted pathogenic enzyme matrix metalloproteinase-9 which does not require the use of biological antibodies. PMID:20424776

  16. Matrix metalloproteinase 2 genotype is associated with nonanastomotic biliary strictures after orthotopic liver transplantation

    NARCIS (Netherlands)

    Ten Hove, W. Rogier; Korkmaz, Kerem S.; den Dries, Sanna Op; de Rooij, Bert-Jan F.; van Hoek, Bart; Porte, Robert J.; van der Reijden, Johan J.; Coenraad, Minneke J.; Dubbeld, Jeroen; Hommes, Daniel W.; Verspaget, Hein W.

    Background: Nonanastomotic biliary strictures (NAS) are a serious complication after orthotopic liver transplantation (OLT). Matrix metalloproteinases (MMPs) are involved in connective tissue remodelling in chronic liver disease and complications after OLT. Aim: To evaluate the relationship between

  17. Metalloproteinase Profiling in Lung Transplant Recipients With Good Outcome and Bronchiolitis Obliterans Syndrome

    NARCIS (Netherlands)

    Heijink, Irene H.; Rozeveld, Dennie; van der Heide, Sicco; Bij, van der Wim; Bischoff, Rainer; Oosterhout, van Antoon J,; van der Toorn, Marco

    Background. Bronchiolitis obliterans syndrome (BOS), the major cause of death on lung transplantation, is characterized by bronchiolar inflammation and tissue remodeling. Matrix metalloproteinases (MMPs) have been implicated in these processes, although it is still unclear whether MMP activity and

  18. Matrix metalloproteinases in inflammatory bowel disease : expression, regulation and clinical relevance

    NARCIS (Netherlands)

    Meijer, Martin Jan-Willem

    2009-01-01

    Crohn’s disease (CD) is characterized by chronic, patchy, transmural inflammation of the entire gastrointestinal tract, while ulcerative colitis (UC) is manifested by chronic, continuous, superficial inflammation of the colon. Matrix metalloproteinases (MMPs) constitute a family of matrix degrading

  19. Matrix metalloproteinase 2 and 9 activity in patients with colorectal cancer liver metastasis.

    NARCIS (Netherlands)

    Waas, E.T.; Wobbes, Th.; Lomme, R.M.L.M.; Groot, J.H. de; Ruers, T.J.M.; Hendriks, T.

    2003-01-01

    BACKGROUND: Matrix metalloproteinases (MMPs) have been reported to play an important role in tumour cell invasion and metastasis. The bioactivity of MMPs in liver metastasis from colorectal cancer was investigated and correlated with clinicopathological variables. METHOD: Thirty-two patients

  20. Increased expression of matrix metalloproteinases in the murine zymosan-induced multiple organ dysfunction syndrome.

    NARCIS (Netherlands)

    Volman, T.J.H.; Goris, R.J.A.; Lomme, R.M.L.M.; Groot, J. de; Verhofstad, A.A.J.; Hendriks, T.

    2004-01-01

    Matrix metalloproteinases (MMPs) have been implicated as mediators of tissue damage in several inflammatory diseases. Since the multiple organ dysfunction syndrome (MODS) is thought to result from systemic inflammation, overactivation of MMPs could contribute to the organ damage observed. The

  1. Matrix metalloproteinase inhibition reduces intimal hyperplasia in a porcine arteriovenous-graft model

    NARCIS (Netherlands)

    Rotmans, Joris I.; Velema, Evelyn; Verhagen, Hence J. M.; Blankensteijn, Jan D.; de kleijn, Dominique P. V.; Stroes, Erik S. G.; Pasterkamp, Gerard

    2004-01-01

    Background: The patency of arteriovenous (AV) polytetrafluoroethylene grafts for hemodialysis is impaired by intimal hyperplasia (IH) at the venous outflow tract. IH mainly consists of vascular smooth muscle cells, fibroblasts, and extracellular matrix proteins. Because matrix metalloproteinases

  2. Matrix metalloproteinase inhibition reduces intimal hyperplasia in a porcine arteriovenous-graft model.

    NARCIS (Netherlands)

    Rotmans, J.I.; Velema, E.; Verhagen, H.J.; Blankensteijn, J.D.; Kleijn, D.P. de; Stroes, E.S.; Pasterkamp, G.

    2004-01-01

    BACKGROUND: The patency of arteriovenous (AV) polytetrafluoroethylene grafts for hemodialysis is impaired by intimal hyperplasia (IH) at the venous outflow tract. IH mainly consists of vascular smooth muscle cells, fibroblasts, and extracellular matrix proteins. Because matrix metalloproteinases

  3. Matrix metalloproteinase inhibition reduces intimal hyperplasia in a porcine arteriovenous-graft model

    NARCIS (Netherlands)

    Rotmans, JI; Velema, E; Verhagen, HJM; Blankensteijn, JD; de Kleijn, DPV; Stroes, ESG; Pasterkamp, G

    Background: The patency of arteriovenous (AV) polytetrafluoroethylene grafts for hemodialysis is impaired by intimal hyperplasia (IH) at the venous outflow tract. IH mainly consists of vascular smooth muscle cells, fibroblasts, and extracellular matrix proteins. Because matrix metalloproteinases

  4. Unraveling the distinctive features of hemorrhagic and non-hemorrhagic snake venom metalloproteinases using molecular simulations

    Science.gov (United States)

    de Souza, Raoni Almeida; Díaz, Natalia; Nagem, Ronaldo Alves Pinto; Ferreira, Rafaela Salgado; Suárez, Dimas

    2016-01-01

    Snake venom metalloproteinases are important toxins that play fundamental roles during envenomation. They share a structurally similar catalytic domain, but with diverse hemorrhagic capabilities. To understand the structural basis for this difference, we build and compare two dynamical models, one for the hemorrhagic atroxlysin-I from Bothrops atrox and the other for the non-hemorraghic leucurolysin-a from Bothrops leucurus. The analysis of the extended molecular dynamics simulations shows some changes in the local structure, flexibility and surface determinants that can contribute to explain the different hemorrhagic activity of the two enzymes. In agreement with previous results, the long Ω-loop (from residue 149 to 177) has a larger mobility in the hemorrhagic protein. In addition, we find some potentially-relevant differences at the base of the S1' pocket, what may be interesting for the structure-based design of new anti-venom agents. However, the sharpest differences in the computational models of atroxlysin-I and leucurolysin-a are observed in the surface electrostatic potential around the active site region, suggesting thus that the hemorrhagic versus non-hemorrhagic activity is probably determined by protein surface determinants.

  5. Inhibition of Snake Venom Metalloproteinase by β-Lactoglobulin Peptide from Buffalo (Bubalus bubalis) Colostrum.

    Science.gov (United States)

    Arpitha, Ashok; Sebastin Santhosh, M; Rohit, A C; Girish, K S; Vinod, D; Aparna, H S

    2017-08-01

    Bioactive peptide research has experienced considerable therapeutic interest owing to varied physiological functions, efficacy in excretion, and tolerability of peptides. Colostrum is a rich natural source of bioactive peptides with many properties elucidated such as anti-thrombotic, anti-hypertensive, opioid, immunomodulatory, etc. In this study, a variant peptide derived from β-lactoglobulin from buffalo colostrum was evaluated for the anti-ophidian property by targeting snake venom metalloproteinases. These are responsible for rapid local tissue damages that develop after snakebite such as edema, hemorrhage, myonecrosis, and extracellular matrix degradation. The peptide identified by LC-MS/MS effectively neutralized hemorrhagic activity of the Echis carinatus venom in a dose-dependent manner. Histological examinations revealed that the peptide mitigated basement membrane degradation and accumulation of inflammatory leucocytes at the venom-injected site. Inhibition of proteolytic activity was evidenced in both casein and gelatin zymograms. Also, inhibition of fibrinolytic and fibrinogenolytic activities was seen. The UV-visible spectral study implicated Zn 2+ chelation, which was further confirmed by molecular docking and dynamic studies by assessing molecular interactions, thus implicating the probable mechanism for inhibition of venom-induced proteolytic and hemorrhagic activities. The present investigation establishes newer vista for the BLG-col peptide with anti-ophidian efficacy as a promising candidate for therapeutic interventions.

  6. Matrix metalloproteinase (MMP) 9 transcription in mouse brain induced by fear learning.

    Science.gov (United States)

    Ganguly, Krishnendu; Rejmak, Emilia; Mikosz, Marta; Nikolaev, Evgeni; Knapska, Ewelina; Kaczmarek, Leszek

    2013-07-19

    Memory formation requires learning-based molecular and structural changes in neurons, whereas matrix metalloproteinase (MMP) 9 is involved in the synaptic plasticity by cleaving extracellular matrix proteins and, thus, is associated with learning processes in the mammalian brain. Because the mechanisms of MMP-9 transcription in the brain are poorly understood, this study aimed to elucidate regulation of MMP-9 gene expression in the mouse brain after fear learning. We show here that contextual fear conditioning markedly increases MMP-9 transcription, followed by enhanced enzymatic levels in the three major brain structures implicated in fear learning, i.e. the amygdala, hippocampus, and prefrontal cortex. To reveal the role of AP-1 transcription factor in MMP-9 gene expression, we have used reporter gene constructs with specifically mutated AP-1 gene promoter sites. The constructs were introduced into the medial prefrontal cortex of neonatal mouse pups by electroporation, and the regulation of MMP-9 transcription was studied after contextual fear conditioning in the adult animals. Specifically, -42/-50- and -478/-486-bp AP-1 binding motifs of the mouse MMP-9 promoter sequence have been found to play a major role in MMP-9 gene activation. Furthermore, increases in MMP-9 gene promoter binding by the AP-1 transcription factor proteins c-Fos and c-Jun have been demonstrated in all three brain structures under investigation. Hence, our results suggest that AP-1 acts as a positive regulator of MMP-9 transcription in the brain following fear learning.

  7. Identification of dihydrogambogic acid as a matrix metalloproteinase 1 inhibitor by high-throughput screening

    Directory of Open Access Journals (Sweden)

    Li Y

    2017-12-01

    Full Text Available Yong Li, John J Voorhees, Gary J FisherDepartment of Dermatology, University of Michigan, Ann Arbor, MI, USAType I collagen (COL1 is the predominant structural protein in the skin. COL1 forms densely packed fibrils which are essential for maintaining skin mechanical properties and youthful appearance.1 The enzyme matrix metalloproteinase-1 (MMP1 cleaves COL1 fibrils at a single site.2 Once cleaved by MMP1, COL1 fibrils can be degraded by other proteases. MMP1 expression is elevated during natural aging and chronic sun exposure, ie, photoaging, leading to excessive degradation of COL1.3 This excessive degradation contributes to COL1 deficiency in the skin of the elderly. COL1 deficiency impairs skin structural integrity and appearance.Given the detrimental role of MMP1 in mediating age-associated fragmentation of COL1 fibrils, it would be beneficial to include MMP1 inhibitors in topical antiaging skin care products. Naturally existing substances that are safe for human use, such as botanical extracts, are often used in skin care products. We have utilized highthroughput screening (HTS to identify naturally existing MMP1 inhibitors that could be used for cosmetic purposes.

  8. Matrix Metalloproteinase-9 (MMP-9 polymorphisms in patients with cutaneous malignant melanoma

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    Busam Klaus

    2007-03-01

    Full Text Available Abstract Background Cutaneous Malignant Melanoma causes over 75% of skin cancer-related deaths, and it is clear that many factors may contribute to the outcome. Matrix Metalloproteinases (MMPs play an important role in the degradation and remodeling of the extracellular matrix and basement membrane that, in turn, modulate cell division, migration and angiogenesis. Some polymorphisms are known to influence gene expression, protein activity, stability, and interactions, and they were shown to be associated with certain tumor phenotypes and cancer risk. Methods We tested seven polymorphisms within the MMP-9 gene in 1002 patients with melanoma in order to evaluate germline genetic variants and their association with progression and known risk factors of melanoma. The polymorphisms were selected based on previously published reports and their known or potential functional relevance using in-silico methods. Germline DNA was then genotyped using pyrosequencing, melting temperature profiles, heteroduplex analysis, and fragment size analysis. Results We found that reference alleles were present in higher frequency in patients who tend to sunburn, have family history of melanoma, higher melanoma stage, intransit metastasis and desmoplastic melanomas among others. However, after adjustment for age, sex, phenotypic index, moles, and freckles only Q279R, P574R and R668Q had significant associations with intransit metastasis, propensity to tan/sunburn and primary melanoma site. Conclusion This study does not provide strong evidence for further investigation into the role of the MMP-9 SNPs in melanoma progression.

  9. Serum Matrix Metalloproteinase-9 and Cognitive Impairment After Acute Ischemic Stroke.

    Science.gov (United States)

    Zhong, Chongke; Bu, Xiaoqing; Xu, Tan; Guo, Libing; Wang, Xuemei; Zhang, Jintao; Cui, Yong; Li, Dong; Zhang, Jianhui; Ju, Zhong; Chen, Chung-Shiuan; Chen, Jing; Zhang, Yonghong; He, Jiang

    2018-01-06

    The impact of serum matrix metalloproteinases-9 (MMP-9) on cognitive impairment after ischemic stroke is unclear. We aimed to investigate the association between serum MMP-9 in the short-term acute phase of ischemic stroke and cognitive impairment at 3 months. Our study was based on a subsample from the CATIS (China Antihypertensive Trial in Acute Ischemic Stroke); a total of 558 patients with serum MMP-9 levels from 7 of 26 participating sites of the trial were included in this analysis. Cognitive impairment severity was categorized as severe, mild, or none (Mini-Mental State Examination score, impairment was defined as a score of impairment and 153 (27.4%) had severe cognitive impairment at 3 months. After adjustment for age, National Institutes of Health stroke score, education, and other covariates, the odds ratio for the highest quartile of serum MMP-9 compared with the lowest quartile was 3.20 (95% confidence interval, 1.87-5.49) for cognitive impairment. Multiple-adjusted spline regression model showed a linear association between MMP-9 levels and cognitive impairment ( P impairment was defined by Montreal Cognitive Assessment score. Increased serum MMP-9 levels in the short-term phase of ischemic stroke were associated with 3-month cognitive impairment, independently of established risk factors. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  10. EMMPRIN mediates beta-adrenergic receptor-stimulated matrix metalloproteinase activity in cardiac myocytes.

    OpenAIRE

    Siwik Deborah A; Kuster Gabriela M; Brahmbhatt Jamin V; Zaidi Zaheer; Malik Julia; Ooi Henry; Ghorayeb Ghassan

    2008-01-01

    Extracellular matrix metalloproteinase inducer (EMMPRIN) expression is increased in myocardium from patients with dilated cardiomyopathy and animal models of heart failure. However little is known about the regulated expression or functional role of EMMPRIN in the myocardium. In rat cardiac cells EMMPRIN is expressed on myocytes but not endothelial cells or fibroblasts. Therefore we tested the hypothesis that EMMPRIN expression regulates matrix metalloproteinase (MMP) activity in rat ventricu...

  11. Reduced Levels of Tissue Inhibitors of Metalloproteinases in UVB-Irradiated Corneal Epithelium

    Czech Academy of Sciences Publication Activity Database

    Ardan, Taras; Němcová, Lucie; Bohuslavová, Božena; Klezlová, A.; Popelka, Štěpán; Studenovská, Hana; Hrnčiarová, Eva; Čejková, Jitka; Motlík, Jan

    2016-01-01

    Roč. 92, č. 5 (2016), s. 720-727 ISSN 0031-8655 R&D Projects: GA ČR GPP302/10/P155; GA MŠk(CZ) LO1609 Institutional support: RVO:67985904 ; RVO:61389013 ; RVO:68378041 Keywords : tissue inhibitors of metalloproteinases * matrix metalloproteinases Subject RIV: EB - Genetics ; Molecular Biology; CD - Macromolecular Chemistry (UMCH-V) Impact factor: 2.121, year: 2016

  12. Embryo apoptosis identification: Oocyte grade or cleavage stage?

    Science.gov (United States)

    Bakri, Noraina Mohd; Ibrahim, Siti Fatimah; Osman, Nurul Atikah; Hasan, Nurhaslina; Jaffar, Farah Hanan Fathihah; Rahman, Zulaiha Abdul; Osman, Khairul

    2015-01-01

    Apoptosis is a programed cell death that is vital for tissue homeostasis. However, embryo apoptosis had been known to be related to embryo fragmentation which should be avoided in in vitro fertilization (IVF). The purpose of this study was to evaluate the relationship of embryo apoptosis with the grade of immature oocytes and cleavage stage of in vitro produced (IVP) cattle embryos. This study consisted of 345 oocytes collected through ovary slicing. Immature oocytes were graded as A, B and C. This grading was based on cumulus cell thickness and compactness. All oocytes then underwent an in vitro maturation (IVM) procedure. An IVF was done 24 h after IVM culture. Prior to staining, stage of cleaved embryos was determined and classified as either 2, 4, 8 or >8-cell embryo stage. Apoptosis status of cleaved IVP embryos was determined by using annexin V-FITC staining technique at 48 and 72 h post insemination (hpi). Apoptosis status for each embryo was classified as either early or late. The result showed that there was no significant difference (p > 0.05) of apoptosis status among grade A, B and C embryos. All grades of oocytes showed embryo apoptosis where 1.5% late apoptosis for grade A, 4.5% and 10.4% of early and late apoptosis for grade B and grade C. Early apoptosis was not seen in grade A embryo. We also noted no significant difference (p > 0.05) of apoptosis status between 2, 4, 8 and >8-cell embryo stage. Early apoptosis was also not seen in >8-cell stage. Even though there were no differences in apoptosis expression between the three classes, the cleavage rate of grade A oocytes was significantly higher (p < 0.01) than grade B and grade C. In conclusion, the apoptosis expression in the embryo can occur regardless of the oocyte quality and the cleavage stage of the embryo produced. PMID:26858565

  13. Zinc and metalloproteinases 2 and 9: What is their relation with breast cancer?

    Directory of Open Access Journals (Sweden)

    Aldenora Oliveira do Nascimento Holanda

    Full Text Available Summary Zinc is the catalytic component of proteins that regulate responses to DNA damage, intracellular signaling enzymes, and matrix metalloproteinases, which are important proteins in carcinogenesis. The objective of this review is to bring current information on the participation of zinc and matrix metalloproteinases types 2 and 9 in mechanisms involved in the pathogenesis of breast cancer. We conducted a literature review, in consultation with the PubMed, Lilacs, and Scielo databases. The zinc and cysteine residues are structural elements shared by all members of the family of matrix metalloproteinases, and these proteins appear to be involved in the propagation of various types of neoplasms, including breast cancer. Moreover, transported zinc is likely to be used for the metalation of the catalytic domain of the newly synthesized metalloproteinases before the latter are secreted. Accordingly, increase in zinc concentrations in cellular compartments and the reduction of this trace element in the blood of patients with breast cancer appear to alter the activity of metalloproteinases 2 and 9, contributing to the occurrence of malignancy. Thus, it is necessary to carry out further studies with a view to clarify the role of zinc and metalloproteinases 2 and 9 in the pathogenesis of breast cancer.

  14. ADAM and ADAMTS Family Proteins and Snake Venom Metalloproteinases: A Structural Overview

    Directory of Open Access Journals (Sweden)

    Soichi Takeda

    2016-05-01

    Full Text Available A disintegrin and metalloproteinase (ADAM family proteins constitute a major class of membrane-anchored multidomain proteinases that are responsible for the shedding of cell-surface protein ectodomains, including the latent forms of growth factors, cytokines, receptors and other molecules. Snake venom metalloproteinases (SVMPs are major components in most viper venoms. SVMPs are primarily responsible for hemorrhagic activity and may also interfere with the hemostatic system in envenomed animals. SVMPs are phylogenetically most closely related to ADAMs and, together with ADAMs and related ADAM with thrombospondin motifs (ADAMTS family proteinases, constitute adamalysins/reprolysins or the M12B clan (MEROPS database of metalloproteinases. Although the catalytic domain structure is topologically similar to that of other metalloproteinases such as matrix metalloproteinases, the M12B proteinases have a modular structure with multiple non-catalytic ancillary domains that are not found in other proteinases. Notably, crystallographic studies revealed that, in addition to the conserved metalloproteinase domain, M12B members share a hallmark cysteine-rich domain designated as the “ADAM_CR” domain. Despite their name, ADAMTSs lack disintegrin-like structures and instead comprise two ADAM_CR domains. This review highlights the current state of our knowledge on the three-dimensional structures of M12B proteinases, focusing on their unique domains that may collaboratively participate in directing these proteinases to specific substrates.

  15. Matrix metalloproteinase 9 level as an indicator for restenosis following cervical and intracranial angioplasty and stenting

    Directory of Open Access Journals (Sweden)

    Jun-peng Liu

    2015-01-01

    Full Text Available Cervical and intracranial angioplasty and stenting is an effective and safe method of reducing the risk of ischemic stroke, but it may be affected by in-stent restenosis. The present study investigated serum level of matrix metalloproteinase 9 as a predictor of restenosis after 40 patients underwent cervical and/or intracranial angioplasty and stenting. Results showed that restenosis occurred in 30% (3/10 of patients when the serum level of matrix metalloproteinase 9 at 3 days after surgery was 2.5 times higher than preoperative level. No restenosis occurred when the serum level of matrix metalloproteinase 9 at 3 days after surgery was not 2.5 times higher than preoperative level. Restenosis occurred in 12% (2/17 of patients when the serum level of matrix metalloproteinase 9 was higher than preoperative level for more than 30 days after surgery, but only occurred in 4% (1/23 of patients when the serum level of matrix metalloproteinase 9 was higher than preoperative level for less than 30 days after surgery. However, the differences observed were not statistically significant (P > 0.05. Experimental findings indicate that when the serum level of matrix metalloproteinase 9 is 2.5 times higher than preoperative level at 3 days after cervical and intracranial angioplasty and stenting, it may serve as a predictor of in-stent restenosis.

  16. Structural differences of matrix metalloproteinases with potential implications for inhibitor selectivity examined by the GRID/CPCA approach

    DEFF Research Database (Denmark)

    Terp, Gitte Elgaard; Cruciani, Gabriele; Christensen, Inge Thøger

    2002-01-01

    The matrix metalloproteinases (MMPs) are a family of proteolytic enzymes, which have been the focus of a lot of research in recent years because of their involvement in various disease conditions. In this study, structures of 10 enzymes (MMP1, MMP2, MMP3, MMP7, MMP8, MMP9, MMP12, MMP13, MMP14......, and MMP20) were examined with the intention of highlighting regions that could be potential sites for obtaining selectivity. For this purpose, the GRID/CPCA approach as implemented in GOLPE was used. Counterions were included to take into account the different electrostatic properties of the proteins......, and the GRID calculations were performed, allowing the protein side chains to move in response to interaction with the probes. In the search for selectivity, the MMPs are known to be a very difficult case because the enzymes of this family are very similar. The well-known differences in the S1' pocket were...

  17. Human aqueous humor levels of transforming growth factor-β2: Association with matrix metalloproteinases/tissue inhibitors of matrix metalloproteinases

    OpenAIRE

    Jia, Yan; Yue, Yu; Hu, Dan-Ning; Chen, Ji-Li; Zhou, Ji-Bo

    2017-01-01

    The present study aims to investigate the association of transforming growth factor-β2 (TGF-β2) and matrix metalloproteinases (MMPs), MMP-2 and MMP-3, and tissue inhibitors of matrix metalloproteinases (TIMPs), TIMP-1, TIMP-2 and TIMP-3 in the aqueous humor of patients with high myopia or cataracts. The levels of TGF-β2 and MMPs/TIMPs were measured with the Luminex xMAP Technology using commercially available Milliplex xMAP kits. The association between TGF-β2 and MMPs/TIMPs levels was analyz...

  18. Granzyme B mediates both direct and indirect cleavage of extracellular matrix in skin after chronic low-dose ultraviolet light irradiation.

    Science.gov (United States)

    Parkinson, Leigh G; Toro, Ana; Zhao, Hongyan; Brown, Keddie; Tebbutt, Scott J; Granville, David J

    2015-02-01

    Extracellular matrix (ECM) degradation is a hallmark of many chronic inflammatory diseases that can lead to a loss of function, aging, and disease progression. Ultraviolet light (UV) irradiation from the sun is widely considered as the major cause of visible human skin aging, causing increased inflammation and enhanced ECM degradation. Granzyme B (GzmB), a serine protease that is expressed by a variety of cells, accumulates in the extracellular milieu during chronic inflammation and cleaves a number of ECM proteins. We hypothesized that GzmB contributes to ECM degradation in the skin after UV irradiation through both direct cleavage of ECM proteins and indirectly through the induction of other proteinases. Wild-type and GzmB-knockout mice were repeatedly exposed to minimal erythemal doses of solar-simulated UV irradiation for 20 weeks. GzmB expression was significantly increased in wild-type treated skin compared to nonirradiated controls, colocalizing to keratinocytes and to an increased mast cell population. GzmB deficiency significantly protected against the formation of wrinkles and the loss of dermal collagen density, which was related to the cleavage of decorin, an abundant proteoglycan involved in collagen fibrillogenesis and integrity. GzmB also cleaved fibronectin, and GzmB-mediated fibronectin fragments increased the expression of collagen-degrading matrix metalloproteinase-1 (MMP-1) in fibroblasts. Collectively, these findings indicate a significant role for GzmB in ECM degradation that may have implications in many age-related chronic inflammatory diseases. © 2014 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  19. Single-Molecule Analysis for RISC Assembly and Target Cleavage.

    Science.gov (United States)

    Sasaki, Hiroshi M; Tadakuma, Hisashi; Tomari, Yukihide

    2018-01-01

    RNA-induced silencing complex (RISC) is a small RNA-protein complex that mediates silencing of complementary target RNAs. Biochemistry has been successfully used to characterize the molecular mechanism of RISC assembly and function for nearly two decades. However, further dissection of intermediate states during the reactions has been warranted to fill in the gaps in our understanding of RNA silencing mechanisms. Single-molecule analysis with total internal reflection fluorescence (TIRF) microscopy is a powerful imaging-based approach to interrogate complex formation and dynamics at the individual molecule level with high sensitivity. Combining this technique with our recently established in vitro reconstitution system of fly Ago2-RISC, we have developed a single-molecule observation system for RISC assembly. In this chapter, we summarize the detailed protocol for single-molecule analysis of chaperone-assisted assembly of fly Ago2-RISC as well as its target cleavage reaction.

  20. 3' RNA ligase mediated rapid amplification of cDNA ends for validating viroid induced cleavage at the 3' extremity of the host mRNA.

    Science.gov (United States)

    Adkar-Purushothama, Charith Raj; Bru, Pierrick; Perreault, Jean-Pierre

    2017-12-01

    5' RNA ligase-mediated rapid amplification of cDNA ends (5' RLM-RACE) is a widely-accepted method for the validation of direct cleavage of a target gene by a microRNA (miRNA) and viroid-derived small RNA (vd-sRNA). However, this method cannot be used if cleavage takes place in the 3' extremity of the target RNA, as this gives insufficient sequence length to design nested PCR primers for 5' RLM RACE. To overcome this hurdle, we have developed 3' RNA ligase-mediated rapid amplification of cDNA ends (3' RLM RACE). In this method, an oligonucleotide adapter having 5' adenylated and 3' blocked is ligated to the 3' end of the cleaved RNA followed by PCR amplification using gene specific primers. In other words, in 3' RLM RACE, 3' end is mapped using 5' fragment instead of small 3' fragment. The method developed here was verified by examining the bioinformatics predicted and parallel analysis of RNA ends (PARE) proved cleavage sites of chloride channel protein CLC-b-like mRNA in Potato spindle tuber viroid infected tomato plants. The 3' RLM RACE developed in this study has the potential to validate the miRNA and vd-sRNA mediated cleavage of mRNAs at its 3' untranslated region (3' UTR). Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Proteolytic processing of the cilium adhesin MHJ_0194 (P123J ) in Mycoplasma hyopneumoniae generates a functionally diverse array of cleavage fragments that bind multiple host molecules.

    Science.gov (United States)

    Raymond, Benjamin B A; Jenkins, Cheryl; Seymour, Lisa M; Tacchi, Jessica L; Widjaja, Michael; Jarocki, Veronica M; Deutscher, Ania T; Turnbull, Lynne; Whitchurch, Cynthia B; Padula, Matthew P; Djordjevic, Steven P

    2015-03-01

    Mycoplasma hyopneumoniae, the aetiological agent of porcine enzootic pneumonia, regulates the presentation of proteins on its cell surface via endoproteolysis, including those of the cilial adhesin P123 (MHJ_0194). These proteolytic cleavage events create functional adhesins that bind to proteoglycans and glycoproteins on the surface of ciliated and non-ciliated epithelial cells and to the circulatory host molecule plasminogen. Two dominant cleavage events of the P123 preprotein have been previously characterized; however, immunoblotting studies suggest that more complex processing events occur. These extensive processing events are characterized here. The functional significance of the P97 cleavage fragments is also poorly understood. Affinity chromatography using heparin, fibronectin and plasminogen as bait and peptide arrays were used to expand our knowledge of the adhesive capabilities of P123 cleavage fragments and characterize a novel binding motif in the C-terminus of P123. Further, we use immunohistochemistry to examine in vivo, the biological significance of interactions between M. hyopneumoniae and fibronectin and show that M. hyopneumoniae induces fibronectin deposition at the site of infection on the ciliated epithelium. Our data supports the hypothesis that M. hyopneumoniae possesses the molecular machinery to influence key molecular communication pathways in host cells. © 2014 John Wiley & Sons Ltd.

  2. Ultrarapid mutation detection by multiplex, solid-phase chemical cleavage

    Energy Technology Data Exchange (ETDEWEB)

    Rowley, G.; Saad, S.; Giannelli, F.; Green, P.M. [Guy`s & St. Thomas`s Hospitals, London (United Kingdom)

    1995-12-10

    The chemical cleavage of mismatches in heteroduplexes formed by probe and test DNA detects and locates any sequence change in long DNA segments ({approximately}1.8 kb), and its efficiency has been well tested in the analysis of both average (e.g., coagulation factor IX) and large, complex genes (e.g., coagulation factor VIII and dystrophin). In the latter application RT/PCR products allow the examination of all essential sequences of the gene in a minimum number of reactions. We use two specific chemical reactants (hydroxylamine and osmium tetroxide) and piperidine cleavage of the above procedure to develop a very fast mutation screening method. This is based on: (1) 5{prime} or internal fluorescent labeling to allow concurrent screening of three to four DNA fragments and (2) solid-phase chemistry to use a microliter format and reduce the time required for the procedure, from amplification of sequence to gel loading inclusive, to one person-working-day. We test the two variations of the method, one entailing 5{prime} labeling of probe DNA and the other uniform labeling of both probe and target DNA, by detecting 114 known hemophilia B (coagulation factor IX) mutations and by analyzing 129 new patients. Uniform labeling of both probe and target DNA prior to formation of the heteroduplexes leads to almost twofold redundancy in the ability to detect mutations. Alternatively, the latter procedure may offer very efficient though less than 100% screening for sequence changes with only hydroxylamine. The full method with two chemical reactions (hydroxylamine and osmium tetroxide) should allow one person to screen with virtually 100% accuracy more than 300 kb of sequence in three ABI 373 gels in 1 day. 26 refs., 7 figs., 1 tab.

  3. Modelling of ductile and cleavage fracture by local approach

    International Nuclear Information System (INIS)

    Samal, M.K.; Dutta, B.K.; Kushwaha, H.S.

    2000-08-01

    This report describes the modelling of ductile and cleavage fracture processes by local approach. It is now well known that the conventional fracture mechanics method based on single parameter criteria is not adequate to model the fracture processes. It is because of the existence of effect of size and geometry of flaw, loading type and rate on the fracture resistance behaviour of any structure. Hence, it is questionable to use same fracture resistance curves as determined from standard tests in the analysis of real life components because of existence of all the above effects. So, there is need to have a method in which the parameters used for the analysis will be true material properties, i.e. independent of geometry and size. One of the solutions to the above problem is the use of local approaches. These approaches have been extensively studied and applied to different materials (including SA33 Gr.6) in this report. Each method has been studied and reported in a separate section. This report has been divided into five sections. Section-I gives a brief review of the fundamentals of fracture process. Section-II deals with modelling of ductile fracture by locally uncoupled type of models. In this section, the critical cavity growth parameters of the different models have been determined for the primary heat transport (PHT) piping material of Indian pressurised heavy water reactor (PHWR). A comparative study has been done among different models. The dependency of the critical parameters on stress triaxiality factor has also been studied. It is observed that Rice and Tracey's model is the most suitable one. But, its parameters are not fully independent of triaxiality factor. For this purpose, a modification to Rice and Tracery's model is suggested in Section-III. Section-IV deals with modelling of ductile fracture process by locally coupled type of models. Section-V deals with the modelling of cleavage fracture process by Beremins model, which is based on Weibulls

  4. Micromechanisms and toughness for cleavage fracture of steel

    International Nuclear Information System (INIS)

    Rosenfield, A.R.; Majumdar, B.S.

    1987-01-01

    A complete understanding of the fracture mechanisms of steel in the ductile/brittle transition region requires analysis not only of crack initiation, but also of crack propagation. This paper reviews micrographic and fractographic experiments that give insight into both phenomena, and suggests a frame-work through which both may be related. Unstable cleavage crack initiation can occur after some blunting of the original fatigue precrack or after some stable crack growth. In either event, instability appears to be triggered by the fracture of a brittle micro-constituent ahead of the precrack. The large scatter in reported K IC values within the transition region reflects the size distribution and relative scarcity of these 'trigger' particles. While a large number of models have attempted to correlate toughness in the ductile/brittle transition regime to events occurring ahead of the crack tip, surprisingly little attention has been paid to events occurring behind the crack front. Fractographic evidence as well as metallographic sectioning of arrested cracks show that the mechanism of rapid crack propagation by cleavage is affected strongly by partial crack-plane deflection which leaves unbroken ligaments in its wake. The tearing of these ligaments by dimple-rupture is the dominant energy-absorbing mechanism. Etch-pit experiments using an Fe-Si alloy show that the crack-tip stress intensity based on plastic zone size is extremely low. It is suggested that the mechanism of crack arrest should be modeled using a sharp crack which is restrained by a distribution of discrete pinching forces along its faces. The same model is applied to crack initiation. (orig.)

  5. Cell Death-Associated Ribosomal RNA Cleavage in Postmortem Tissues and Its Forensic Applications.

    Science.gov (United States)

    Kim, Ji Yeon; Kim, Yunmi; Cha, Hyo Kyeong; Lim, Hye Young; Kim, Hyungsub; Chung, Sooyoung; Hwang, Juck-Joon; Park, Seong Hwan; Son, Gi Hoon

    2017-06-30

    Estimation of postmortem interval (PMI) is a key issue in the field of forensic pathology. With the availability of quantitative analysis of RNA levels in postmortem tissues, several studies have assessed the postmortem degradation of constitutively expressed RNA species to estimate PMI. However, conventional RNA quantification as well as biochemical and physiological changes employed thus far have limitations related to standardization or normalization. The present study focuses on an interesting feature of the subdomains of certain RNA species, in which they are site-specifically cleaved during apoptotic cell death. We found that the D8 divergent domain of ribosomal RNA (rRNA) bearing cell death-related cleavage sites was rapidly removed during postmortem RNA degradation. In contrast to the fragile domain, the 5' terminal region of 28S rRNA was remarkably stable during the postmortem period. Importantly, the differences in the degradation rates between the two domains in mammalian 28S rRNA were highly proportional to increasing PMI with a significant linear correlation observed in mice as well as human autopsy tissues. In conclusion, we demonstrate that comparison of the degradation rates between domains of a single RNA species provides quantitative information on postmortem degradation states, which can be applied for the estimation of PMI.

  6. Bothrops jararaca venom metalloproteinases are essential for coagulopathy and increase plasma tissue factor levels during envenomation.

    Directory of Open Access Journals (Sweden)

    Karine M Yamashita

    2014-05-01

    Full Text Available BACKGROUND/AIMS: Bleeding tendency, coagulopathy and platelet disorders are recurrent manifestations in snakebites occurring worldwide. We reasoned that by damaging tissues and/or activating cells at the site of the bite and systemically, snake venom toxins might release or decrypt tissue factor (TF, resulting in activation of blood coagulation and aggravation of the bleeding tendency. Thus, we addressed (a whether TF and protein disulfide isomerase (PDI, an oxireductase involved in TF encryption/decryption, were altered in experimental snake envenomation; (b the involvement and significance of snake venom metalloproteinases (SVMP and serine proteinases (SVSP to hemostatic disturbances. METHODS/PRINCIPAL FINDINGS: Crude Bothrops jararaca venom (BjV was preincubated with Na2-EDTA or AEBSF, which are inhibitors of SVMP and SVSP, respectively, and injected subcutaneously or intravenously into rats to analyze the contribution of local lesion to the development of hemostatic disturbances. Samples of blood, lung and skin were collected and analyzed at 3 and 6 h. Platelet counts were markedly diminished in rats, and neither Na2-EDTA nor AEBSF could effectively abrogate this fall. However, Na2-EDTA markedly reduced plasma fibrinogen consumption and hemorrhage at the site of BjV inoculation. Na2-EDTA also abolished the marked elevation in TF levels in plasma at 3 and 6 h, by both administration routes. Moreover, increased TF activity was also noticed in lung and skin tissue samples at 6 h. However, factor VII levels did not decrease over time. PDI expression in skin was normal at 3 h, and downregulated at 6 h in all groups treated with BjV. CONCLUSIONS: SVMP induce coagulopathy, hemorrhage and increased TF levels in plasma, but neither SVMP nor SVSP are directly involved in thrombocytopenia. High levels of TF in plasma and TF decryption occur during snake envenomation, like true disseminated intravascular coagulation syndrome, and might be implicated in

  7. A Genetic Programming Method for the Identification of Signal Peptides and Prediction of Their Cleavage Sites

    Directory of Open Access Journals (Sweden)

    David Lennartsson

    2004-01-01

    Full Text Available A novel approach to signal peptide identification is presented. We use an evolutionary algorithm for automatic evolution of classification programs, so-called programmatic motifs. The variant of evolutionary algorithm used is called genetic programming where a population of solution candidates in the form of full computer programs is evolved, based on training examples consisting of signal peptide sequences. The method is compared with a previous work using artificial neural network (ANN approaches. Some advantages compared to ANNs are noted. The programmatic motif can perform computational tasks beyond that of feed-forward neural networks and has also other advantages such as readability. The best motif evolved was analyzed and shown to detect the h-region of the signal peptide. A powerful parallel computer cluster was used for the experiment.

  8. Haemophilia B caused by mutation of a potential thrombin cleavage site in factor IX

    Energy Technology Data Exchange (ETDEWEB)

    Winship, P.R. (Univ. of Oxford (England))

    1990-03-11

    Haemophilia B is a blood coagulation disorder caused by mutations in the factor IX gene giving functionally defective or reduced levels of factor IX protein circulating in the plasma. The mutation in the Caucasian patient under investigation, Haemophilia B Oxford h5 (Oxh5), was characterized at the DNA level by constructing a genomic library using leucocyte-derived DNA from the patient. Overlapping recombinant clones spanning the entire factor IX locus were isolated which then allowed the generation of a series of sub-clones across all eight exons (a-h) plus the 5{prime} and 3{prime} flanking sequences known to be important in regulation of the gene and polyadenylation of the mRNA species.

  9. Using model complexes to augment and advance metalloproteinase inhibitor design.

    Science.gov (United States)

    Jacobsen, Faith E; Cohen, Seth M

    2004-05-17

    The tetrahedral zinc complex [(Tp(Ph,Me))ZnOH] (Tp(Ph,Me) = hydrotris(3,5-phenylmethylpyrazolyl)borate) was combined with 2-thenylmercaptan, ethyl 4,4,4-trifluoroacetoacetate, salicylic acid, salicylamide, thiosalicylic acid, thiosalicylamide, methyl salicylate, methyl thiosalicyliate, and 2-hydroxyacetophenone to form the corresponding [(Tp(Ph,Me))Zn(ZBG)] complexes (ZBG = zinc-binding group). X-ray crystal structures of these complexes were obtained to determine the mode of binding for each ZBG, several of which had been previously studied with SAR by NMR (structure-activity relationship by nuclear magnetic resonance) as potential ligands for use in matrix metalloproteinase inhibitors. The [(Tp(Ph,Me))Zn(ZBG)] complexes show that hydrogen bonding and donor atom acidity have a pronounced effect on the mode of binding for this series of ligands. The results of these studies give valuable insight into how ligand protonation state and intramolecular hydrogen bonds can influence the coordination mode of metal-binding proteinase inhibitors. The findings here suggest that model-based approaches can be used to augment drug discovery methods applied to metalloproteins and can aid second-generation drug design.

  10. Evaluation of matrix metalloproteinase-9 expressions in nasopharyngeal carcinoma patients

    Science.gov (United States)

    Farhat; Asnir, R. A.; Yudhistira, A.; Daulay, E. R.; Puspitasari, D.; Yulius, S.

    2018-03-01

    Nasopharyngeal carcinoma (NPC) is one of head and neck cancer with a poor prognosis because of the position of the tumor adjacent to the skull base and vital structures. Degradation of extracellular matrix that will cause tumor cells to invade surrounding tissues, vascular or lymphatic vessels. One that plays a role in the extracellular matrix degradation process is matrix metalloproteinase-9 (MMP-9). MMP-9 plays a role in tumor invasion process, metastasis and induction of tumor tissue vascularization. To determine the expression of MMP-9 in patients with nasopharyngeal carcinoma, a descriptive study was conducted by examining immunohistochemistry MMP-9 in 30 NPC tissues that had never received radiotherapy, chemotherapy or combination. Frequency distribution of NPC patient mostly in the age group 41-50 years old and 51-60 years were nine people (30.0%); men (73.3%) and non-keratinizing squamous cell carcinoma (53.3%) histopathology type. The overexpression of MMP-9 in patients with nasopharyngeal carcinoma were mostly found in advance stage.

  11. Matrix metalloproteinase expression in excimer laser wounded rabbit corneas

    Science.gov (United States)

    Hahn, Taewon; Chamon, Wallace; Akova, Yonja; Stark, Walter J.; Stetler-Stevenson, William G.; Azar, Dimitri T.

    1994-06-01

    This study was performed to obtain information about matrix metalloproteinase (MMP) expression in excimer-wounded corneas and to determine whether MMPs expression correlates with the depth of the ablation. 6-mm excimer keratectomy (60 or 180 micrometers ) was performed using the 193-mm ArF excimer laser on 12 NZW rabbits. Corneas treated with mechanical epithelial debridement and untreated corneas served as controls. Rabbits were killed at 20 and 30 hr after laser ablation. Zymography after SDS extraction was performed on regenerated central epithelium and the central stroma to determine MMPs expression. We observed enzymatic activity of a 92 KDa band in the epithelium of excimer-ablated corneas but not in that following debridement wounds and untreated controls. The expression of the 92 KDa MMP was most pronounced with the deeper excimer ablation. A 72 KDa band of enzymatic activity present in the stroma of all treated and control eyes was also seen in the epithelium of excimer-ablated corneas. These proteolytic enzymes may play an important role in wound healing and remodelling after excimer keratectomy.

  12. Matrix metalloproteinases with gelatinolytic activity induced by Paracoccidioides brasiliensis infection

    Science.gov (United States)

    Nishikaku, Angela Satie; Ribeiro, Luciana Cristina; Molina, Raphael Fagnani Sanchez; Albe, Bernardo Paulo; Cunha, Cláudia da Silva; Burger, Eva

    2009-01-01

    Matrix metalloproteinases (MMPs) modulate extracellular matrix turnover, inflammation and immunity. We studied MMP-9 and MMP-2 in experimental paracoccidioidomycosis. At 15 and 120 days after infection (DAI) with virulent Paracoccidioides brasiliensis, MMP-9 was positive by immunohistochemistry in multinucleated giant cells, in mononuclear cells with macrophage and lymphocyte morphologies and also in fungal cells in the lesions of susceptible and resistant mice. Using gelatin zymography, pro- and active MMP-9 and active MMP-2 were detected in all infected mice, but not in controls. Gelatinolytic activity was not observed in P. brasiliensis extracts. Semiquantitative analysis of gelatinolytic activities revealed weak or absent MMP-2 and strong MMP-9 activity in both mouse strains at 15 DAI, declining at 120 DAI. Avirulent P. brasiliensis-infected mice had residual lesions with MMP-9-positive pseudoxantomatous macrophages, but no gelatinase activity at 120 DAI. Our findings demonstrate the induction of MMPs, particularly MMP-9, in experimental paracoccidioidomycosis, suggesting a possible influence in the pattern of granulomas and in fungal dissemination. PMID:19765107

  13. Expression of matrix metalloproteinases in patients with bipolar disorder

    Directory of Open Access Journals (Sweden)

    Fábria Chiarani

    2013-12-01

    Full Text Available Objective: High cardiovascular mortality rates have been reported in patients with bipolar disorder (BD. Studies indicate that matrix metalloproteinases (MMPs are implicated in cardiovascular diseases. We evaluated the expression pattern of MMP-2 and MMP-9 in blood from patients with BD during acute mania and after euthymia, in comparison with healthy controls. Methods: Twenty patients and 20 controls were recruited and matched for sex and age. MMP messenger RNA (mRNA levels were measured using real-time quantitative polymerase chain reaction (PCR. Body mass index (BMI was calculated for all subjects. Results: There were no significant differences in MMP-2 and MMP-9 mRNA expression between patients and controls. mRNA levels were not significantly different during mania and euthymia. However, MMP-2 mRNA levels were negatively associated with BMI in BD patients and positively associated with BMI in controls. There was no difference in the pattern of MMP-9 expression between patients and controls. Conclusions: Our results suggest a different pattern of association between MMP-2 and BMI in BD patients as compared with controls. Despite some study limitations, we believe that the role of MMPs in BD should be further investigated to elucidate its relationship with cardiovascular risk.

  14. Omentin-1 prevents cartilage matrix destruction by regulating matrix metalloproteinases.

    Science.gov (United States)

    Li, Zhigang; Liu, Baoyi; Zhao, Dewei; Wang, BenJie; Liu, Yupeng; Zhang, Yao; Li, Borui; Tian, Fengde

    2017-08-01

    Matrix metalloproteinases (MMPs) play a crucial role in the degradation of the extracellular matrix and pathological progression of osteoarthritis (OA). Omentin-1 is a newly identified anti-inflammatory adipokine. Little information regarding the protective effects of omentin-1 in OA has been reported before. In the current study, our results indicated that omentin-1 suppressed expression of MMP-1, MMP-3, and MMP-13 induced by the proinflammatory cytokine interleukin-1β (IL-1β) at both the mRNA and protein levels in human chondrocytes. Importantly, administration of omentin-1 abolished IL-1β-induced degradation of type II collagen (Col II) and aggrecan, the two major extracellular matrix components in articular cartilage, in a dose-dependent manner. Mechanistically, omentin-1 ameliorated the expression of interferon regulatory factor 1 (IRF-1) by blocking the JAK-2/STAT3 pathway. Our results indicate that omentin-1 may have a potential chondroprotective therapeutic capacity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  15. Inhibition of matrix metalloproteinase-2 by PARP inhibitors

    International Nuclear Information System (INIS)

    Nicolescu, Adrian C.; Holt, Andrew; Kandasamy, Arulmozhi D.; Pacher, Pal; Schulz, Richard

    2009-01-01

    Matrix metalloproteinase-2 (MMP-2), a ubiquitously expressed zinc-dependent endopeptidase, and poly(ADP-ribosyl) polymerase (PARP), a nuclear enzyme regulating DNA repair, are activated by nitroxidative stress associated with various pathologies. As MMP-2 plays a detrimental role in heart injuries resulting from enhanced nitroxidative stress, where PARP and MMP inhibitors are beneficial, we hypothesized that PARP inhibitors may affect MMP-2 activity. Using substrate degradation assays to determine MMP-2 activity we found that four PARP inhibitors (3-AB, PJ-34, 5-AIQ, and EB-47) inhibited 64 kDa MMP-2 in a concentration-dependent manner. The IC 50 values of PJ-34 and 5-AIQ were in the high micromolar range and comparable to those of known MMP-2 inhibitors doxycycline, minocycline or o-phenanthroline, whereas those for 3-AB and EB-47 were in the millimolar range. Co-incubation of PARP inhibitors with doxycycline showed an additive inhibition of MMP-2 that was significant for 3-AB alone. These data demonstrate that the protective effects of some PARP inhibitors may include inhibition of MMP-2 activity.

  16. Inhibition of matrix metalloproteinase-2 by PARP inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Nicolescu, Adrian C.; Holt, Andrew; Kandasamy, Arulmozhi D. [Departments of Pharmacology and Pediatrics, Cardiovascular Research Centre, University of Alberta, Edmonton, Alta., Canada T6G 2S2 (Canada); Pacher, Pal [National Institutes of Health, NIAAA, Laboratory of Physiologic Studies, Bethesda, MD (United States); Schulz, Richard, E-mail: richard.schulz@ualberta.ca [Departments of Pharmacology and Pediatrics, Cardiovascular Research Centre, University of Alberta, Edmonton, Alta., Canada T6G 2S2 (Canada)

    2009-10-02

    Matrix metalloproteinase-2 (MMP-2), a ubiquitously expressed zinc-dependent endopeptidase, and poly(ADP-ribosyl) polymerase (PARP), a nuclear enzyme regulating DNA repair, are activated by nitroxidative stress associated with various pathologies. As MMP-2 plays a detrimental role in heart injuries resulting from enhanced nitroxidative stress, where PARP and MMP inhibitors are beneficial, we hypothesized that PARP inhibitors may affect MMP-2 activity. Using substrate degradation assays to determine MMP-2 activity we found that four PARP inhibitors (3-AB, PJ-34, 5-AIQ, and EB-47) inhibited 64 kDa MMP-2 in a concentration-dependent manner. The IC{sub 50} values of PJ-34 and 5-AIQ were in the high micromolar range and comparable to those of known MMP-2 inhibitors doxycycline, minocycline or o-phenanthroline, whereas those for 3-AB and EB-47 were in the millimolar range. Co-incubation of PARP inhibitors with doxycycline showed an additive inhibition of MMP-2 that was significant for 3-AB alone. These data demonstrate that the protective effects of some PARP inhibitors may include inhibition of MMP-2 activity.

  17. High matrix metalloproteinase activity is a hallmark of periapical granulomas.

    Science.gov (United States)

    de Paula-Silva, Francisco Wanderley Garcia; D'Silva, Nisha J; da Silva, Léa Assed Bezerra; Kapila, Yvonne Lorraine

    2009-09-01

    The inability to distinguish periapical cysts from granulomas before performing root canal treatment leads to uncertainty in treatment outcomes because cysts have lower healing rates. Searching for differential expression of molecules within cysts or granulomas could provide information with regard to the identity of the lesion or suggest mechanistic differences that may form the basis for future therapeutic intervention. Thus, we investigated whether granulomas and cysts exhibit differential expression of extracellular matrix (ECM) molecules. Human periapical granulomas, periapical cysts, and healthy periodontal ligament tissues were used to investigate the differential expression of ECM molecules by microarray analysis. Because matrix metalloproteinases (MMP) showed the highest differential expression in the microarray analysis, MMPs were further examined by in situ zymography and immunohistochemistry. Data were analyzed by using one-way analysis of variance followed by the Tukey test. We observed that cysts and granulomas differentially expressed several ECM molecules, especially those from the MMP family. Compared with cysts, granulomas exhibited higher MMP enzymatic activity in areas stained for MMP-9. These areas were composed of polymorphonuclear cells (PMNs) in contrast to cysts. Similarly, MMP-13 was expressed by a greater number of cells in granulomas compared with cysts. Our findings indicate that high enzymatic MMP activity in PMNs together with MMP-9 and MMP-13 stained cells could be a molecular signature of granulomas unlike periapical cysts.

  18. Role of matrix metalloproteinases in radicular cysts and periapical granulomas.

    Science.gov (United States)

    D'addazio, G; Artese, L; Piccirilli, M; Perfetti, G

    2014-01-01

    The aim of the present study was to evaluate the expression and distribution of different classes of matrix metalloproteinases (MMPs) in radicular cysts and periapical granulomas. Twenty consecutive specimens of radicular cysts and 20 of periapical granulomas were selected. Expression of MMP-2, -9, -8, -13, -3 was immunohistochemically evaluated. The intensity of expression of the MMPs was evaluated using a semi-quantitative analysis: low = +; intermediate = ++; high = +++. Positive expression of MMPs was present with different distribution. MMP-9 expressed differently in the lesions. Indeed, in periapical granulomas low expression was found in endothelial cells and fibroblasts, whilst high intensities were only detected in inflammatory cells. On the contrary, in radicular cysts the high intensities were mainly present in keratinocytes and fibroblasts. MMP-8 was mainly expressed in inflammatory cells of periapical granulomas. MMP-2 and -3 presented a low intensity of expression in both groups. MMP-13 showed a variable pattern of distribution in the different cell types of the two different lesions. The present investigation supports the role of MMPs in the inflammatory process leading to the development of radicular cysts and periapical granulomas. The results of the present study suggested that the increased enlargement of radicular cysts, compared to periapical granulomas, might be related to a higher expression of MMP-9. On the other hands, the higher intensity of expression of MMP-8 in periapical granulomas could be related to an active inflammatory process. MMP-8 could play an important role in the inflammation processes during the development of periapical lesions.

  19. Matrix metalloproteinase gene polymorphisms in patients with coronary artery disease

    Directory of Open Access Journals (Sweden)

    Vanessa L.N. Dalepiane

    2007-01-01

    Full Text Available Matrix metalloproteinases (MMPs play an important role in the pathogenesis of atherosclerosis, the pathology underlying the majority of coronary artery disease (CAD. In this study we tested the hypothesis that polymorphic variation in the MMP genes influences the risk of developing atherosclerosis. We analyzed functional polymorphisms in the promoter of the MMP-1, MMP-3, MMP-9 and MMP-12 genes in 183 Brazilian Caucasian individuals submitted to coronary angiography, of which 67 (37% had normal coronary arteries (control group and 116 (63% had CAD (CAD patient group. The -1607 1G/2G MMP-1, -1171 5A/6A MMP-3, -1562 C/T MMP-9, -82 A/G MMP-12 polymorphisms were analyzed by PCR followed by restriction digestion. No significant differences were observed in allele frequencies between the CAD patients and controls. Haplotype analysis showed no differences between the CAD patients and controls. There was a significant difference in the severity of CAD, as assessed by the number of diseased vessels, in MMP-1 1G/1G homozygous individuals and in those homozygous for the 6A allele of the MMP-3 polymorphism. However, multivariate analysis showed that diabetes mellitus was the only variable independently associated with CAD severity. Our findings indicated that MMP polymorphisms have no significant impact on the risk and severity of CAD.

  20. Immunohistochemical expression of matrix metalloproteinase 13 in chronic periodontitis.

    Science.gov (United States)

    Nagasupriya, Alapati; Rao, Donimukkala Bheemalingeswara; Ravikanth, Manyam; Kumar, Nalabolu Govind; Ramachandran, Cinnamanoor Rajmani; Saraswathi, Thillai Rajashekaran

    2014-01-01

    The extracellular matrix is a complex integrated system responsible for the physiologic properties of connective tissue. Collagen is the major extracellular component that is altered in pathologic conditions, mainly periodontitis. The destruction involves proteolytic enzymes, primarily matrix metalloproteinases (MMPs), which play a key role in mediating and regulating the connective tissue destruction in periodontitis. The study group included 40 patients with clinically diagnosed chronic periodontitis. The control group included 20 patients with clinically normal gingiva covering impacted third molars undergoing extraction or in areas where crown-lengthening procedures were performed. MMP-13 expression was demonstrated using immunohistochemistry in all the gingival biopsies, and the data were analyzed statistically. MMP-13 expression was observed more in chronic periodontitis when compared with normal gingiva. MMP-13 expression was expressed by fibroblasts, lymphocytes, macrophages, plasma cells, and basal cells of the sulcular epithelium. Comparative evaluation of all the clinical and histologic parameters with MMP-13 expression showed high statistical significance with Spearman correlation coefficient. Elevated levels of MMP-13 may play a role in the pathogenesis of chronic periodontitis. There is a direct correlation of increased expression of MMP-13 with various clinical and histologic parameters in disease severity.

  1. Correlation of bacterial coinfection versus matrix metalloproteinase 9 and tissue inhibitor of metalloproteinase 1 expression in aortic aneurysm and atherosclerosis.

    Science.gov (United States)

    Roggério, Alessandra; Sambiase, Nádia Vieira; Palomino, Suely A P; de Castro, Maria Alice Pedreira; da Silva, Erasmo Simão; Stolf, Noedir G; de Lourdes Higuchi, Maria

    2013-10-01

    We searched for any relationship between Chlamydophila pneumoniae, Mycoplasma pneumoniae, matrix metalloproteinase 9 (MMP-9), and tissue inhibitor of metalloproteinase 1 (TIMP-1) in aneurysmatic atherosclerotic lesions, and whether this relationship differed from that in atherosclerotic nonaneurysmatic lesions. Twenty-eight tissue samples paired by age and sex were grouped as follows: group 1 included 14 nonaneurysmal atherosclerotic fragments obtained from abdominal aortas collected from necropsies; group 2 included 14 aneurysmatic atherosclerotic aortic fragments obtained from patients during corrective surgery. Immunohistochemistry reactions were evaluated for C pneumoniae, M pneumoniae, MMP-9, and TIMP-1 antigens. Both groups were compared using the Mann-Whitney test, and the correlations among variables were obtained using the Spearman correlation test. P ≤ 0.05 was considered statistically significant. C pneumoniae and M pneumoniae antigens were detected in 100% of cases. A higher amount of C pneumoniae (P = 0.005), M pneumoniae (P = 0.002), and MMP-9 (P = 0.021) was found in adventitia of group 2 with aneurysm. A positive correlation was found in the aneurysm group, as follows: intima C pneumoniae versus adventitia thickness (r = 0.70; P = 0.01), media C pneumoniae versus adventitia C pneumoniae (r = 0.75; P = 0.002), intima C pneumoniae versus media C pneumoniae (r = 0.8; P = 0.00), and adventitia C pneumoniae versus intima M pneumoniae (r = 0.54; P = 0.05); negative correlations were as follows: adventitia thickness and adventitia M pneumoniae (r = -0.65; P = 0.01), media MMP-9 and media thickness (r = -0.55; P = 0.04), TIMP-1 media versus adventitia C pneumoniae (r = -0.86; P = 0.00), and TIMP-1 media versus M pneumoniae intima (r = -0.67; P = 0.03). Nonaneurysmal atherosclerotic group 1 results are as follows: adventitia C pneumoniae versus TIMP-1 media (r = 0.75; P = 0.01) and media C pneumoniae and adventitia C pneumoniae (r = 0.59; P = 0.03). The

  2. Matrix metalloproteinases, tissue inhibitors of matrix metalloproteinases and angiogenic cytokines in peripheral blood of patients with thyroid cancer.

    Science.gov (United States)

    Komorowski, Jan; Pasieka, Z; Jankiewicz-Wika, J; Stepień, H

    2002-08-01

    Stimulation of growth of endothelial cells from preexisting blood vessels, i.e., angiogenesis, is one of the essential elements necessary to create a permissive environment in which a tumor can grow. During angiogenesis, the matrix metalloproteinase (MMP) family of tissue enzymes contributes to normal (embriogenesis or wound repair) and pathologic tissue remodeling (chronic inflammation and tumor genesis). The proposed pathogenic roles of MMPs in cancer are tissue breakdown and remodeling during invasive tumor growth and tumor angiogenesis. Tissue inhibitors of metalloproteinases (TIMPs) form a complex with MMPs, which in turn inhibits active MMPs. Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are unique among mediators of angiogenesis with synergistic effect, and both can also be secreted by thyroid cancer cells. The goal of the study was to evaluate the plasma blood concentration of VEGF, bFGF, MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, TIMP-1, and TIMP-2 in patients with cancer and in normal subjects. Twenty-two patients with thyroid cancers (papillary cancer, 11; partly papillary and partly follicular cancer, 3; anaplastic cancer, 5; medullary cancer, 3) and 16 healthy subjects (controls) were included in the study. VEGF, bFGF MMPs, and TIMPs were evaluated by enzyme-linked immunosorbent assay (ELISA). In patients with thyroid cancer, normal VEGF concentrations (74.29 +/- 13.38 vs. 84.85 +/- 21.71 pg/mL; p > 0.05) and increased bFGF (29.52 +/- 4.99 vs. 6.05 +/- 1.43 pg/mL; p < 0.001), MMP-2 (605.95 +/- 81.83 vs. 148.75 +/- 43.53 ng/mL; p < 0.001), TIMP-2 (114.19 +/- 6.62 vs. 60.75 +/- 9.18 ng/mL; p < 0.001), as well as lower MMP-1 (0.70 +/- 0.42 vs. 3.87 +/- 0.53; p < 0.001) levels have been noted. Increased plasma levels of MMP-3 and MMP-9 were also found in patients with medullary carcinoma. In conclusion, predominance of MMP-2 over TIMP-2 and TIMP-1 over MMP-1 as well as increased concentration of bFGF in peripheral blood are

  3. Comparative and phylogenetic perspectives of the cleavage process in tailed amphibians.

    Science.gov (United States)

    Desnitskiy, Alexey G; Litvinchuk, Spartak N

    2015-10-01

    The order Caudata includes about 660 species and displays a variety of important developmental traits such as cleavage pattern and egg size. However, the cleavage process of tailed amphibians has never been analyzed within a phylogenetic framework. We use published data on the embryos of 36 species concerning the character of the third cleavage furrow (latitudinal, longitudinal or variable) and the magnitude of synchronous cleavage period (up to 3-4 synchronous cell divisions in the animal hemisphere or a considerably longer series of synchronous divisions followed by midblastula transition). Several species from basal caudate families Cryptobranchidae (Andrias davidianus and Cryptobranchus alleganiensis) and Hynobiidae (Onychodactylus japonicus) as well as several representatives from derived families Plethodontidae (Desmognathus fuscus and Ensatina eschscholtzii) and Proteidae (Necturus maculosus) are characterized by longitudinal furrows of the third cleavage and the loss of synchrony as early as the 8-cell stage. By contrast, many representatives of derived families Ambystomatidae and Salamandridae have latitudinal furrows of the third cleavage and extensive period of synchronous divisions. Our analysis of these ontogenetic characters mapped onto a phylogenetic tree shows that the cleavage pattern of large, yolky eggs with short series of synchronous divisions is an ancestral trait for the tailed amphibians, while the data on the orientation of third cleavage furrows seem to be ambiguous with respect to phylogeny. Nevertheless, the midblastula transition, which is characteristic of the model species Ambystoma mexicanum (Caudata) and Xenopus laevis (Anura), might have evolved convergently in these two amphibian orders.

  4. RecA-mediated cleavage reaction of Lambda repressor and DNA ...

    African Journals Online (AJOL)

    PRECIOUS

    2010-01-11

    Jan 11, 2010 ... hydrolyze ATP at all, but fulfills RecA functions such as cleavage of Lambda repressor and strand .... DNA binding properties of RecA and may result in an in- .... AMP-PNP there is no cleavage of Lambda repressor (Figure.

  5. Temporal and spatial expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 in trophoblast and endometrial epithelium during pregnancy of pig

    Czech Academy of Sciences Publication Activity Database

    Georgieva, R.; Rashev, P.; Pěknicová, Jana; Michailova, A.

    2004-01-01

    Roč. 52, Suppl.1 (2004), s. 42-43 ISSN 1046-7408. [International Congress of Reproductive Immunology /9./. Hakone, 11.10.2004-15.10.2004] Institutional research plan: CEZ:AV0Z5052915 Keywords : matrix metalloproteinase * trophoblast * endometrium Subject RIV: EC - Immunology Impact factor: 1.808, year: 2004

  6. Role of aberrant metalloproteinase activity in the pro-inflammatory phenotype of bronchial epithelium in COPD

    Directory of Open Access Journals (Sweden)

    Postma Dirkje S

    2011-08-01

    Full Text Available Abstract Background Cigarette smoke, the major risk factor for COPD, is known to activate matrix metalloproteinases in airway epithelium. We investigated whether metalloproteinases, particularly A Disintegrin and Metalloproteinase (ADAM17, contribute to increased pro-inflammatory epithelial responses with respect to the release of IL-8 and TGF-α, cytokines implicated in COPD pathogenesis. Methods We studied the effects of cigarette smoke extract (CSE and metalloproteinase inhibitors on TGF-α and IL-8 release in primary bronchial epithelial cells (PBECs from COPD patients, healthy smokers and non-smokers. Results We observed that TGF-α was mainly shed by ADAM17 in PBECs from all groups. Interestingly, IL-8 production occurred independently from ADAM17 and TGF-α shedding, but was significantly inhibited by broad-spectrum metalloproteinase inhibitor TAPI-2. CSE did not induce ADAM17-dependent TGF-α shedding, while it slightly augmented the production of IL-8. This was accompanied by reduced endogenous inhibitor of metalloproteinase (TIMP-3 levels, suggesting that CSE does not directly but rather indirectly alter activity of ADAM17 through the regulation of its endogenous inhibitor. Furthermore, whereas baseline TGF-α shedding was lower in COPD PBECs, the early release of IL-8 (likely due to its shedding was higher in PBECs from COPD than healthy smokers. Importantly, this was accompanied by lower TIMP-2 levels in COPD PBECs, while baseline TIMP-3 levels were similar between groups. Conclusions Our data indicate that IL-8 secretion is regulated independently from ADAM17 activity and TGF-α shedding and that particularly its early release is differentially regulated in PBECs from COPD and healthy smokers. Since TIMP-2-sensitive metalloproteinases could potentially contribute to IL-8 release, these may be interesting targets to further investigate novel therapeutic strategies in COPD.

  7. Omega-3 and Omega-6 Fatty Acids Act as Inhibitors of the Matrix Metalloproteinase-2 and Matrix Metalloproteinase-9 Activity.

    Science.gov (United States)

    Nicolai, Eleonora; Sinibaldi, Federica; Sannino, Gianpaolo; Laganà, Giuseppina; Basoli, Francesco; Licoccia, Silvia; Cozza, Paola; Santucci, Roberto; Piro, Maria Cristina

    2017-08-01

    Polyunsaturated fatty acids have been reported to play a protective role in a wide range of diseases characterized by an increased metalloproteinases (MMPs) activity. The recent finding that omega-3 and omega-6 fatty acids exert an anti-inflammatory effect in periodontal diseases has stimulated the present study, designed to determine whether such properties derive from a direct inhibitory action of these compounds on the activity of MMPs. To this issue, we investigated the effect exerted by omega-3 and omega-6 fatty acids on the activity of MMP-2 and MMP-9, two enzymes that actively participate to the destruction of the organic matrix of dentin following demineralization operated by bacteria acids. Data obtained (both in vitro and on ex-vivo teeth) reveal that omega-3 and omega-6 fatty acids inhibit the proteolytic activity of MMP-2 and MMP-9, two enzymes present in dentin. This observation is of interest since it assigns to these compounds a key role as MMPs inhibitors, and stimulates further study to better define their therapeutic potentialities in carious decay.

  8. In vitro induction of matrix metalloproteinase-2 and matrix metalloproteinase-9 expression in keratinocytes by boron and manganese.

    Science.gov (United States)

    Chebassier, Nathalie; El Houssein, Ouijja; Viegas, Isabelle; Dréno, Brigitte

    2004-08-01

    Matrix metalloproteinase (MMP)-2 and MMP-9 are involved in keratinocyte migration and granulation tissue remodeling during wound healing. Thermal water cures are sometimes proposed as complementary treatment for accelerating healing of wounds resulting from burns and/or surgery, but their mechanisms of action remain unknown. Some thermal waters are rich in trace elements such as boron and manganese. Interestingly, clinical studies have shown the beneficial effects of trace elements such as boron and manganese for human wound healing. To try to specify the role of trace elements in cutaneous healing, the present study investigated the effects of these trace elements on the production of MMP-2 and MMP-9 by normal human keratinocytes cultured in vitro. Immunohistochemistry and Western blot showed that intracellular MMP-9 expression in keratinocytes was induced when incubated for 6 h with boron at 10 micro g/ml or manganese at 0.2 micro g/ml. Moreover, gelatin zymography on keratinocyte supernatants showed an increase of gelatinase secretion after 24 h of incubation of keratinocytes with boron or manganese, regardless of concentration. Gelatinase secretion was not associated with keratinocyte proliferation induced by trace elements. Thus, our results suggest that boron and manganese could play a role in the clinical efficiency of thermal water on wound healing.

  9. Matrix Metalloproteinase Stromelysin-1 Triggers a Cascade of Molecular Alterations that leads to stable epithelial-to-Mesenchymal Conversion and a Premalignant Phenotype in Mammary Epithelial Cells

    Energy Technology Data Exchange (ETDEWEB)

    Lochter, A.; Galosy, S.; Muschler, J.; Freedman, N.; Werb, Z.; Bissell, M.J.

    1997-08-11

    Matrix metalloproteinases (MMPs) regulate ductal morphogenesis, apoptosis, and neoplastic progression in mammary epithelial cells. To elucidate the direct effects of MMPs on mammary epithelium, we generated functionally normal cells expressing an inducible autoactivating stromelysin-1 (SL-1) transgene. Induction of SL-1 expression resulted in cleavage of E-cadherin, and triggered progressive phenotypic conversion characterized by disappearance of E-cadherin and catenins from cell-cell contacts, downregulation of cytokeratins, upregulation of vimentin, induction of keratinocyte growth factor expression and activation, and upregulation of endogenous MMPs. Cells expressing SL-1 were unable to undergo lactogenic differentiation and became invasive. Once initiated, this phenotypic conversion was essentially stable, and progressed even in the absence of continued SL-1 expression. These observations demonstrate that inappropriate expression of SL-1 initiates a cascade of events that may represent a coordinated program leading to loss of the differentiated epithelial phenotype and gain of some characteristics of tumor cells. Our data provide novel insights into how MMPs function in development and neoplastic conversion.

  10. Involvement of a cytosine side chain in proton transfer in the rate-determining step of ribozyme self-cleavage

    Science.gov (United States)

    Shih, I-hung; Been, Michael D.

    2001-01-01

    Ribozymes of hepatitis delta virus have been proposed to use an active-site cytosine as an acid-base catalyst in the self-cleavage reaction. In this study, we have examined the role of cytosine in more detail with the antigenomic ribozyme. Evidence that proton transfer in the rate-determining step involved cytosine 76 (C76) was obtained from examining cleavage activity of the wild-type and imidazole buffer-rescued C76-deleted (C76Δ) ribozymes in D2O and H2O. In both reactions, a similar kinetic isotope effect and shift in the apparent pKa indicate that the buffer is functionally substituting for the side chain in proton transfer. Proton inventory of the wild-type reaction supported a mechanism of a single proton transfer at the transition state. This proton transfer step was further characterized by exogenous base rescue of a C76Δ mutant with cytosine and imidazole analogues. For the imidazole analogues that rescued activity, the apparent pKa of the rescue reaction, measured under kcat/KM conditions, correlated with the pKa of the base. From these data a Brønsted coefficient (β) of 0.51 was determined for the base-rescued reaction of C76Δ. This value is consistent with that expected for proton transfer in the transition state. Together, these data provide strong support for a mechanism where an RNA side chain participates directly in general acid or general base catalysis of the wild-type ribozyme to facilitate RNA cleavage. PMID:11171978

  11. Molecular cloning and characterization of cDNAs encoding carotenoid cleavage dioxygenase in bitter melon (Momordica charantia).

    Science.gov (United States)

    Tuan, Pham Anh; Park, Sang Un

    2013-01-01

    Carotenoid cleavage dioxygenases (CCDs) are a family of enzymes that catalyze the oxidative cleavage of carotenoids at various chain positions to form a broad spectrum of apocarotenoids, including aromatic substances, pigments and phytohormones. Using the rapid amplification of cDNA ends (RACE) PCR method, we isolated three cDNA-encoding CCDs (McCCD1, McCCD4, and McNCED) from Momordica charantia. Amino acid sequence alignments showed that they share high sequence identity with other orthologous genes. Quantitative real-time RT PCR (reverse transcriptase PCR) analysis revealed that the expression of McCCD1 and McCCD4 was highest in flowers, and lowest in roots and old leaves (O-leaves). During fruit maturation, the two genes displayed differential expression, with McCCD1 peaking at mid-stage maturation while McCCD4 showed the lowest expression at that stage. The mRNA expression level of McNCED, a key enzyme involved in abscisic acid (ABA) biosynthesis, was high during fruit maturation and further increased at the beginning of seed germination. When first-leaf stage plants of M. charantia were exposed to dehydration stress, McNCED mRNA expression was induced primarily in the leaves and, to a lesser extend, in roots and stems. McNCED expression was also induced by high temperature and salinity, while treatment with exogenous ABA led to a decrease. These results should be helpful in determining the substrates and cleavage sites catalyzed by CCD genes in M. charantia, and also in defining the roles of CCDs in growth and development, and in the plant's response to environmental stress. Copyright © 2012 Elsevier GmbH. All rights reserved.

  12. Developmental expression of membrane type 4-matrix metalloproteinase (Mt4-mmp/Mmp17) in the mouse embryo

    Science.gov (United States)

    Clemente, Cristina; Montalvo, María Gregoria; Seiki, Motoharu; Arroyo, Alicia G.

    2017-01-01

    Matrix metalloproteinases (MMPs) constitute a large group of endoproteases that play important functions during embryonic development, tumor metastasis and angiogenesis by degrading components of the extracellular matrix. Within this family, we focused our study on Mt4-mmp (also called Mmp17) that belongs to a distinct subset that is anchored to the cell surface via a glycosylphosphatidylinositol (GPI) moiety and with the catalytic site exposed to the extracellular space. Information about its function and substrates is very limited to date, and little has been reported on its role in the developing embryo. Here, we report a detailed expression analysis of Mt4-mmp during mouse embryonic development by using a LacZ reporter transgenic mouse line. We showed that Mt4-mmp is detected from early stages of development to postnatal stages following a dynamic and restricted pattern of expression. Mt4-mmp was first detected at E8.5 limited to the intersomitic vascularization, the endocardial endothelium and the dorsal aorta. Mt4-mmpLacZ/+ cells were also observed in the neural crest cells, somites, floor plate and notochord at early stages. From E10.5, expression localized in the limb buds and persists during limb development. A strong expression in the brain begins at E12.5 and continues to postnatal stages. Specifically, staining was observed in the olfactory bulb, cerebral cortex, hippocampus, striatum, septum, dorsal thalamus and the spinal cord. In addition, LacZ-positive cells were also detected during eye development, initially at the hyaloid artery and later on located in the lens and the neural retina. Mt4-mmp expression was confirmed by quantitative RT-PCR and western blot analysis in some embryonic tissues. Our data point to distinct functions for this metalloproteinase during embryonic development, particularly during brain formation, angiogenesis and limb development. PMID:28926609

  13. Isolation and cloning of a metalloproteinase from king cobra snake venom.

    Science.gov (United States)

    Guo, Xiao-Xi; Zeng, Lin; Lee, Wen-Hui; Zhang, Yun; Jin, Yang

    2007-06-01

    A 50 kDa fibrinogenolytic protease, ohagin, from the venom of Ophiophagus hannah was isolated by a combination of gel filtration, ion-exchange and heparin affinity chromatography. Ohagin specifically degraded the alpha-chain of human fibrinogen and the proteolytic activity was completely abolished by EDTA, but not by PMSF, suggesting it is a metalloproteinase. It dose-dependently inhibited platelet aggregation induced by ADP, TMVA and stejnulxin. The full sequence of ohagin was deduced by cDNA cloning and confirmed by protein sequencing and peptide mass fingerprinting. The full-length cDNA sequence of ohagin encodes an open reading frame of 611 amino acids that includes signal peptide, proprotein and mature protein comprising metalloproteinase, disintegrin-like and cysteine-rich domains, suggesting it belongs to P-III class metalloproteinase. In addition, P-III class metalloproteinases from the venom glands of Naja atra, Bungarus multicinctus and Bungarus fasciatus were also cloned in this study. Sequence analysis and phylogenetic analysis indicated that metalloproteinases from elapid snake venoms form a new subgroup of P-III SVMPs.

  14. Curcumin influences hepatic expression patterns of matrix metalloproteinases in liver toxicity.

    Science.gov (United States)

    Rukkumani, Rajagopalan; Aruna, Kode; Varma, Penumathsa Suresh; Menon, Venugopal Padmanabhan

    2004-07-01

    Hepatic fibrosis is a result of an imbalance between enhanced matrix synthesis and diminished breakdown of connective tissue proteins, the net result of which is increased deposition of Extra Cellular Matrix. In this concept Matrix Metalloproteinases play an important role because their activity is largely responsible for extra cellular matrix breakdown. In the present study we have tested the influence of curcumin, the active principle of turmeric, on matrix metalloproteinase expression during alcohol and thermally oxidised sunflower oil induced liver toxicity. Male albino Wistar rats were used for the study. The matrix metalloproteinase expressions were found to be increased significantly in alcohol as well as thermally oxidised sunflower oil groups and on treatment with curcumin there was a significant decrease. In alcohol + thermally oxidised sunflower oil group, we found a significant decrease in matrix metalloproteinase activities. Administration of curcumin significantly improved their activities. From the results obtained, we could conclude that curcumin influences the hepatic matrix metalloproteinases and effectively protects liver against alcohol and delta PUFA induced toxicity.

  15. Expression of matrix metalloproteinase-8 gene in fixed orthodontic patients

    Directory of Open Access Journals (Sweden)

    Susilowati Susilowati

    2011-03-01

    Full Text Available Background: Orthodontic treatment with fixed appliance produces structural and biochemical changes and breaking the balance between the synthesis and the breakdown of the collagen in the periodontium. Matrix metalloproteinase-8 (MMP-8 plays an important role in the remodeling of periodontal ligament during orthodontic movement. Purpose: The purpose of this study was to observe the expression of MMP-8 gene in the gingival crevicular fluid (GCF of fixed orthodontic patients. It is expexted that the result can be used as a reference to decide the proper time for elastomeric chain to be reactivated. Methods: Orthodontic fixed appliances were placed on 8 patients and elastomeric chains exerting 75 grams were attached to produce canine distalization. GCF samples were collected from the distal side of upper canines before force application, 1-, 2-, 3-, and 4 weeks after application consecutively. The samples were analyzed by using RT-PCR. Statistical analyses used were univariate analysis and Mann-WhitneyU test. Results: The expression of MMP-8 in the GCF at t0 was 31.3% but the force application elevated its expression to 65.6% at t1, and then decreased continously at t2, t3, and t4. There was no statistically significant difference of MMP-8 gene expression between t0 and t3. Conclusion: The highest level of MMP-8 gene expression due to orthodontic forces was occured in the first week, but it declined continously in the following weeks. The proper time to reactivate an elastomeric chain was 3 weeks after application.Latar belakang: Perawatan ortodontik dengan peranti cekat menghasilkan perubahan-perubahan stuktural dan biokimiawi pada jaringan periodontal dan mengganggu keseimbangan antara sintesis dan pemecahan kolagen pada periodonsium. Matrix metalloproteinase-8MMP-8 memainkan peran yang penting dalam remodeling ligamentum periodontal selama pergerakan gigi ortodontik. Tujuan: Tujuan dari penelitian ini ialah untuk mengamati ekspresi gen MMP-8

  16. Matrix Metalloproteinases as Therapeutic Targets for Idiopathic Pulmonary Fibrosis

    Science.gov (United States)

    Craig, Vanessa J.; Zhang, Li; Hagood, James S.

    2015-01-01

    Idiopathic pulmonary fibrosis (IPF) is a restrictive lung disease that is associated with high morbidity and mortality. Current medical therapies are not fully effective at limiting mortality in patients with IPF, and new therapies are urgently needed. Matrix metalloproteinases (MMPs) are proteinases that, together, can degrade all components of the extracellular matrix and numerous nonmatrix proteins. MMPs and their inhibitors, tissue inhibitors of MMPs (TIMPs), have been implicated in the pathogenesis of IPF based upon the results of clinical studies reporting elevated levels of MMPs (including MMP-1, MMP-7, MMP-8, and MMP-9) in IPF blood and/or lung samples. Surprisingly, studies of gene-targeted mice in murine models of pulmonary fibrosis (PF) have demonstrated that most MMPs promote (rather than inhibit) the development of PF and have identified diverse mechanisms involved. These mechanisms include MMPs: (1) promoting epithelial-to-mesenchymal transition (MMP-3 and MMP-7); (2) increasing lung levels or activity of profibrotic mediators or reducing lung levels of antifibrotic mediators (MMP-3, MMP-7, and MMP-8); (3) promoting abnormal epithelial cell migration and other aberrant repair processes (MMP-3 and MMP-9); (4) inducing the switching of lung macrophage phenotypes from M1 to M2 types (MMP-10 and MMP-28); and (5) promoting fibrocyte migration (MMP-8). Two MMPs, MMP-13 and MMP-19, have antifibrotic activities in murine models of PF, and two MMPs, MMP-1 and MMP-10, have the potential to limit fibrotic responses to injury. Herein, we review what is known about the contributions of MMPs and TIMPs to the pathogenesis of IPF and discuss their potential as therapeutic targets for IPF. PMID:26121236

  17. Hydrocortisone supresses inflammatory activity of metalloproteinase - 8 in carotid plaque

    Science.gov (United States)

    Gabriel, Sthefano Atique; Antonangelo, Leila; Capelozzi, Vera Luiza; Beteli, Camila Baumann; de Camargo Júnior, Otacílio; de Aquino, José Luis Braga; Caffaro, Roberto Augusto

    2015-01-01

    Objective Matrix metalloproteinases are inflammatory biomarkers involved in carotid plaque instability. Our objective was to analyze the inflammatory activity of plasma and carotid plaque MMP-8 and MMP-9 after intravenous administration of hydrocortisone. Methods The study included 22 patients with stenosis ≥ 70% in the carotid artery (11 symptomatic and 11 asymptomatic) who underwent carotid endarterectomy. The patients were divided into two groups: Control Group - hydrocortisone was not administered, and Group 1 - 500 mg intravenous hydrocortisone was administered during anesthetic induction. Plasma levels of MMP-8 and MMP-9 were measured preoperatively (24 hours before carotid endarterectomy) and at 1 hour, 6 hours and 24 hours after carotid endarterectomy. In carotid plaque, tissue levels of MMP-8 and MMP-9 were measured. Results Group 1 showed increased serum levels of MMP- 8 (994.28 pg/ml and 408.54 pg/ml, respectively; P=0.045) and MMP-9 (106,656.34 and 42,807.69 respectively; P=0.014) at 1 hour after carotid endarterectomy compared to the control group. Symptomatic patients in Group 1 exhibited lower tissue concentration of MMP-8 in comparison to the control group (143.89 pg/ml and 1317.36 respectively; P=0.003). There was a correlation between preoperative MMP-9 levels and tissue concentrations of MMP-8 (P=0.042) and MMP-9 (P=0.019) between symptomatic patients in the control group. Conclusion Hydrocortisone reduces the concentration of MMP- 8 in carotid plaque, especially in symptomatic patients. There was an association between systemic and tissue inflammation. PMID:26313719

  18. Production of matrix metalloproteinases in response to mycobacterial infection.

    Science.gov (United States)

    Quiding-Järbrink, M; Smith, D A; Bancroft, G J

    2001-09-01

    Matrix metalloproteinases (MMPs) constitute a large family of enzymes with specificity for the various proteins of the extracellular matrix which are implicated in tissue remodeling processes and chronic inflammatory conditions. To investigate the role of MMPs in immunity to mycobacterial infections, we incubated murine peritoneal macrophages with viable Mycobacterium bovis BCG or Mycobacterium tuberculosis H37Rv and assayed MMP activity in the supernatants by zymography. Resting macrophages secreted only small amounts of MMP-9 (gelatinase B), but secretion increased dramatically in a dose-dependent manner in response to either BCG or M. tuberculosis in vitro. Incubation with mycobacteria also induced increased MMP-2 (gelatinase A) activity. Neutralization of tumor necrosis alpha (TNF-alpha), and to a lesser extent interleukin 18 (IL-18), substantially reduced MMP production in response to mycobacteria. Exogenous addition of TNF-alpha or IL-18 induced macrophages to express MMPs, even in the absence of bacteria. The immunoregulatory cytokines gamma interferon (IFN-gamma), IL-4, and IL-10 all suppressed BCG-induced MMP production, but through different mechanisms. IFN-gamma treatment increased macrophage secretion of TNF-alpha but still reduced their MMP activity. Conversely, IL-4 and IL-10 seemed to act by reducing the amount of TNF-alpha available to the macrophages. Finally, infection of BALB/c or severe combined immunodeficiency (SCID) mice with either BCG or M. tuberculosis induced substantial increases in MMP-9 activity in infected tissues. In conclusion, we show that mycobacterial infection induces MMP-9 activity both in vitro and in vivo and that this is regulated by TNF-alpha, IL-18, and IFN-gamma. These findings indicate a possible contribution of MMPs to tissue remodeling processes that occur in mycobacterial infections.

  19. Expression of RECK and matrix metalloproteinase-2 in ameloblastoma

    International Nuclear Information System (INIS)

    Zhang, Bin; Zhang, Jin; Xu, Zhi-Ying; Xie, Hong-Liang

    2009-01-01

    Ameloblastoma is a frequent odontogenic benign tumor characterized by local invasiveness, high risk of recurrence and occasional metastasis and malignant transformation. Matrix metalloproteinase-2 (MMP-2) promotes tumor invasion and progression by destroying the extracellular matrix (ECM) and basement membrane. For this proteolytic activity, the endogenous inhibitor is reversion-inducing cysteine rich protein with Kazal motifs (RECK). The aim of this study was to characterize the relationship between RECK and MMP-2 expression and the clinical manifestation of ameloblastoma. Immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) were employed to detect the protein and mRNA expression of RECK and MMP-2 in keratocystic odontogenic tumor (KCOT), ameloblastoma and ameloblastic carcinoma. RECK protein expression was significantly reduced in KCOT (87.5%), ameloblastoma (56.5%) and ameloblastic carcinoma (0%) (P < 0.01), and was significantly lower in recurrent ameloblastoma compared with primary ameloblastoma (P < 0.01), but did not differ by histological type of ameloblastoma. MMP-2 protein expression was significantly higher in ameloblastoma and ameloblastic carcinoma compared with KCOT (P < 0.01). RECK mRNA expression was significantly lower in ameloblastoma than in KCOT (P < 0.01), lower in recurrent ameloblastoma than in primary ameloblastoma, and was negative in ameloblastic carcinoma. MMP-2 mRNA expression was significantly higher in ameloblastoma compared with KCOT (P < 0.01), but was no different in recurrent ameloblastoma versus primary ameloblastoma. RECK protein expression was negatively associated with MMP-2 protein expression in ameloblastoma (r = -0.431, P < 0.01). Low or no RECK expression and increased MMP-2 expression may be associated with negative clinical findings in ameloblastoma. RECK may participate in the invasion, recurrence and malignant transformation of ameloblastoma by regulating MMP-2 at the post

  20. Genetic polymorphisms of matrix metalloproteinase 3 in primary sclerosing cholangitis

    Science.gov (United States)

    Juran, Brian D.; Atkinson, Elizabeth J.; Schlicht, Erik M.; Larson, Joseph J.; Ellinghaus, David; Franke, Andre; Lazaridis, Konstantinos N.

    2011-01-01

    Background The damaging cholestasis inherent to primary sclerosing cholangitis (PSC) results from bile duct stricturing because of progressive fibrosis. The matrix metalloproteinase 3 (MMP3) degrades a wide range of matrix components and is expressed by activated liver stellate cells, and so is a candidate for involvement with the fibrotic processes underlying PSC. Moreover, the MMP3 gene harbours polymorphisms associated with variation in its activity directly impacting clinical phenotypes. Aims We aimed to examine the influence of MMP3 polymorphisms on PSC risk and progression. Methods Nine single nucleotide polymorphisms (SNPs) tagging the common genetic variation of MMP3 were genotyped in 266 PSC patients and 407 controls. SNPs and inferred haplotypes were assessed for PSC association by logistic regression and score tests. The effect of SNPs on survival to liver transplant or death was analysed using Cox regression, and Kaplan–Meier curves were constructed. Results No association of PSC with individual SNPs or haplotypes of MMP3 was detected. However, progression to death or liver transplant was significantly associated with homozygosity for minor alleles of rs522616, rs650108 and rs683878, particularly among PSC patients with concurrent ulcerative colitis (UC) (strongest in redundant SNPs rs650108/rs683878, hazard ratio = 3.23, 95% confidence interval 1.45–7.25, P = 0.004). Conclusions Genetic variation in MMP3 influences PSC progression, possibly in the context of coexisting UC. While the functional variants and specific mechanisms remain unknown, this finding implicates the turnover of the extracellular matrix as an important and variable component of PSC pathogenesis. Efforts to understand this process could form the basis for developing effective treatments, which are currently lacking for PSC. PMID:21134112

  1. Matrix metalloproteinase inhibition reduces contraction by dupuytren fibroblasts.

    Science.gov (United States)

    Townley, William A; Cambrey, Alison D; Khaw, Peng T; Grobbelaar, Adriaan O

    2008-11-01

    Dupuytren's disease is a common fibroproliferative condition of the hand characterized by fibrotic lesions (nodules and cords), leading to disability through progressive digital contracture. Although the etiology of the disease is poorly understood, recent evidence suggests that abnormal matrix metalloproteinase (MMP) activity may play a role in cell-mediated collagen contraction and tissue scarring. The aim of this study was to investigate the efficacy of ilomastat, a broad-spectrum MMP inhibitor, in an in vitro model of Dupuytren fibroblast-mediated contraction. Nodule-derived and cord-derived fibroblasts were isolated from Dupuytren patients; carpal ligament-derived fibroblasts acted as control. Stress-release fibroblast-populated collagen lattices (FPCLs) were used as a model of contraction. FPCLs were allowed to develop mechanical stress (48 hours) during treatment with ilomastat (0-100 micromol/L), released, and allowed to contract over a 48-hour period. Contraction was estimated by measuring lattice area compared with untreated cells or treatment with a control peptide. MMP-1, MMP-2, and MT1-MMP levels were assessed by zymography, Western blotting, and enzyme-linked immunosorbent assay. Nodule-derived fibroblasts contracted lattices (69% +/- 2) to a greater extent than did cord-derived (55% +/- 3) or carpal ligament-derived (55% +/- 1) fibroblasts. Exposure to ilomastat led to significant inhibition of lattice contraction by all fibroblasts, although a reduction in lattice contraction by nodule-derived fibroblasts was most prominent (84% +/- 8). In addition, treatment with ilomastat led to a concomitant suppression of MMP-1 and MMP-2 activity, whereas MT1-MMP activity was found to be upregulated. Our results demonstrate that inhibition of MMP activity results in a reduction in extracellular matrix contraction by Dupuytren fibroblasts and suggest that MMP activity may be a critical target in preventing recurrent contracture caused by this disease.

  2. Mutant matrix metalloproteinase-9 reduces postoperative peritoneal adhesions in rats.

    Science.gov (United States)

    Atta, Hussein; El-Rehany, Mahmoud; Roeb, Elke; Abdel-Ghany, Hend; Ramzy, Maggie; Gaber, Shereen

    2016-02-01

    Postoperative peritoneal adhesions continue to be a major source of morbidity and occasional mortality. Studies have shown that matrix metalloproteinase-9 (MMP-9) levels are decreased postoperatively which may limits matrix degradation and participate in the development of peritoneal adhesions. In this proof-of-principle study, we evaluated the effect of gene therapy with catalytically inactive mutant MMP-9 on postoperative peritoneal adhesions in rats. Adenovirus encoding mutant MMP-9 (Ad-mMMP-9) or saline was instilled in the peritoneal cavity after cecal and parietal peritoneal injury in rats. Expression of mutant MMP-9 transcript was verified by sequencing. Adenovirus E4 gene expression, adhesion scores, MMP-9, tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) and transforming growth factor-β1 (TGF-β1) expression were evaluated at sacrifice one week after treatment. Both mutant MMP-9 transcripts and adenovirus E4 gene were expressed in Ad-mMMP-9 treated adhesions. Adhesions severity decreased significantly (p = 0.036) in the Ad-mMMP-9-treated compared with saline-treated adhesions. Expression of MMP-9 mRNA and protein were elevated (p = 0.001 and p = 0.029, respectively) in the Ad-mMMP-9-treated adhesions compared with saline-treated adhesions. While tPA levels were increased (p = 0.02) in Ad-mMMP-9 treated adhesions compared with saline-treated adhesions, TGF-β1 and PAI-1 levels were decreased (p = 0.017 and p = 0.042, respectively). No difference in mortality were found between groups (p = 0.64). Mutant MMP-9 gene therapy effectively transduced peritoneal adhesions resulting in reduction of severity of primary peritoneal adhesions. Copyright © 2016 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

  3. Matrix metalloproteinases as therapeutic targets for idiopathic pulmonary fibrosis.

    Science.gov (United States)

    Craig, Vanessa J; Zhang, Li; Hagood, James S; Owen, Caroline A

    2015-11-01

    Idiopathic pulmonary fibrosis (IPF) is a restrictive lung disease that is associated with high morbidity and mortality. Current medical therapies are not fully effective at limiting mortality in patients with IPF, and new therapies are urgently needed. Matrix metalloproteinases (MMPs) are proteinases that, together, can degrade all components of the extracellular matrix and numerous nonmatrix proteins. MMPs and their inhibitors, tissue inhibitors of MMPs (TIMPs), have been implicated in the pathogenesis of IPF based upon the results of clinical studies reporting elevated levels of MMPs (including MMP-1, MMP-7, MMP-8, and MMP-9) in IPF blood and/or lung samples. Surprisingly, studies of gene-targeted mice in murine models of pulmonary fibrosis (PF) have demonstrated that most MMPs promote (rather than inhibit) the development of PF and have identified diverse mechanisms involved. These mechanisms include MMPs: (1) promoting epithelial-to-mesenchymal transition (MMP-3 and MMP-7); (2) increasing lung levels or activity of profibrotic mediators or reducing lung levels of antifibrotic mediators (MMP-3, MMP-7, and MMP-8); (3) promoting abnormal epithelial cell migration and other aberrant repair processes (MMP-3 and MMP-9); (4) inducing the switching of lung macrophage phenotypes from M1 to M2 types (MMP-10 and MMP-28); and (5) promoting fibrocyte migration (MMP-8). Two MMPs, MMP-13 and MMP-19, have antifibrotic activities in murine models of PF, and two MMPs, MMP-1 and MMP-10, have the potential to limit fibrotic responses to injury. Herein, we review what is known about the contributions of MMPs and TIMPs to the pathogenesis of IPF and discuss their potential as therapeutic targets for IPF.

  4. Matrix Metalloproteinases Polymorphisms as Prognostic Biomarkers in Malignant Pleural Mesothelioma

    Directory of Open Access Journals (Sweden)

    Danijela Štrbac

    2017-01-01

    Full Text Available Background. Malignant pleural mesothelioma (MPM is a rare disease with a relatively short overall survival (OS. Metalloproteinases (MMPs have a vast biological effect on tumor progression, invasion, metastasis formation, and apoptosis. MMP expression was previously associated with survival in MPM. Our aim was to evaluate if genetic variability of MMP genes could also serve as a prognostic biomarker in MPM. Methods. We genotyped 199 MPM patients for ten polymorphisms: rs243865, rs243849 and rs7201, in MMP2; rs17576, rs17577, rs20544, and rs2250889 in MMP9; and rs1042703, rs1042704, and rs743257 in MMP14. We determined the influence on survival using Cox regression. Results. Carriers of polymorphic MMP9 rs2250889 allele had shorter time to progression (TTP (6.07 versus 10.03 months, HR = 2.45, 95% CI = 1.45–4.14, p=0.001 and OS (9.23 versus 19.2 months, HR = 2.39, 95% CI = 1.37–4.18, p=0.002. In contrast, carriers of at least one polymorphic MMP9 rs20544 allele had longer TTP (10.93 versus 9.40 months, HR = 0.57, 95% CI = 0.38–0.86 p=0.007 and OS (20.67 versus 13.50 months, HR = 0.56, 95% CI = 0.37–0.85, p=0.007. MMP14 rs1042703 was associated with nominally shorter TTP (8.7 versus 9.27 months, HR = 2.09, 95% CI = 1.06–4.12, p=0.032. Conclusions. Selected MMP SNPs were associated with survival and could be used as potential genetic biomarkers in MPM.

  5. Cleavage of olefinic double bonds by mediated anodic oxidation

    International Nuclear Information System (INIS)

    Baeumer, U.-St.; Schaefer, H.J.

    2003-01-01

    Seven alkenes, e.g. 1-decene, methyl oleate, cyclododecene, norbornene, are cleaved by indirect anodic oxidation with IO 4 - /RuCl 3 as mediator to carboxylic acids. The best performance was achieved with two alternative ex cell-methods. Periodate is regenerated from iodate in a divided cell at a PbO 2 /Ti-anode. In the chemical reactor alkene and the produced carboxylic acid are immobilized in a chromatography column on Chromosorb W and oxidized with IO 4 - /RuO 4 in CH 3 CN/water. In the alternative version the alkene is oxidized in an emulsion generated by sonication and the organic phase is retained in the reactor by a separator. Acids and diacids are obtained in 61-91% chemical yield and good current yields. The amount of consumed periodate can be reduced to less than 5% of the amount needed for the chemical oxidation. The mediated anodic cleavage of alkenes is altogether an interesting alternative to ozonolysis

  6. Diaphanous gene mutation affects spiral cleavage and chirality in snails

    Science.gov (United States)

    Kuroda, Reiko; Fujikura, Kohei; Abe, Masanori; Hosoiri, Yuji; Asakawa, Shuichi; Shimizu, Miho; Umeda, Shin; Ichikawa, Futaba; Takahashi, Hiromi

    2016-01-01

    L-R (left and right) symmetry breaking during embryogenesis and the establishment of asymmetric body plan are key issues in developmental biology, but the onset including the handedness-determining gene locus still remains unknown. Using pure dextral (DD) and sinistral (dd) strains of the pond snail Lymnaea stagnalis as well as its F2 through to F10 backcrossed lines, the single handedness-determining-gene locus was mapped by genetic linkage analysis, BAC cloning and chromosome walking. We have identified the actin-related diaphanous gene Lsdia1 as the strongest candidate. Although the cDNA and derived amino acid sequences of the tandemly duplicated Lsdia1 and Lsdia2 genes are very similar, we could discriminate the two genes/proteins in our molecular biology experiments. The Lsdia1 gene of the sinistral strain carries a frameshift mutation that abrogates full-length LsDia1 protein expression. In the dextral strain, it is already translated prior to oviposition. Expression of Lsdia1 (only in the dextral strain) and Lsdia2 (in both chirality) decreases after the 1-cell stage, with no asymmetric localization throughout. The evolutionary relationships among body handedness, SD/SI (spiral deformation/spindle inclination) at the third cleavage, and expression of diaphanous proteins are discussed in comparison with three other pond snails (L. peregra, Physa acuta and Indoplanorbis exustus). PMID:27708420

  7. Sox11 Reduces Caspase-6 Cleavage and Activity.

    Directory of Open Access Journals (Sweden)

    Elaine Waldron-Roby

    Full Text Available The apoptotic cascade is an orchestrated event, whose final stages are mediated by effector caspases. Regulatory binding proteins have been identified for caspases such as caspase-3, -7, -8, and -9. Many of these proteins belong to the inhibitor of apoptosis (IAP family. By contrast, caspase-6 is not believed to be influenced by IAPs, and little is known about its regulation. We therefore performed a yeast-two-hybrid screen using a constitutively inactive form of caspase-6 for bait in order to identify novel regulators of caspase-6 activity. Sox11 was identified as a potential caspase-6 interacting protein. Sox11 was capable of dramatically reducing caspase-6 activity, as well as preventing caspase-6 self- cleavage. Several regions, including amino acids 117-214 and 362-395 within sox11 as well as a nuclear localization signal (NLS all contributed to the reduction in caspase-6 activity. Furthermore, sox11 was also capable of decreasing other effector caspase activity but not initiator caspases -8 and -9. The ability of sox11 to reduce effector caspase activity was also reflected in its capacity to reduce cell death following toxic insult. Interestingly, other sox proteins also had the ability to reduce caspase-6 activity but to a lesser extent than sox11.

  8. Enzymatic carotenoid cleavage in star fruit (Averrhoa carambola).

    Science.gov (United States)

    Fleischmann, Peter; Watanabe, Naoharu; Winterhalter, Peter

    2003-05-01

    This paper presents the first description of an enzyme fraction exhibiting carotenoid cleavage activity isolated from fruit skin of Averrhoa carambola. Partial purification of the enzyme could be achieved by acetone precipitation, ultrafiltration (300 kDa, 50 kDa), isoelectric focusing (pH 3-10) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (7.5%). In this way, an enzymatically active protein fraction was obtained, consisting of four proteins in the molecular weight range of between 12 and 90 kDa. Using beta-carotene as substrate, the enzyme activity was detected spectrophotometrically at 505 nm. The main reaction product, detected by GC analysis, was beta-ionone. This proves that the isolated enzymes are closely related to aroma metabolism and release of star fruit. The time constant of the reaction was 16.6 min, the Michaelis Constant K(m)=3.6 micromol 1(-1) and the maximum velocity V(max)=10.5 x 10(-3) micromol l(-1) s(-1) mg((Protein))(-1). The optimum temperature was 45 degrees C.

  9. Expression of matrix metalloproteinase 9 (MMP-9) and tissue inhibitor of metalloproteinases 1 (TIMP-1) by colorectal cancer cells and adjacent stroma cells--associations with histopathology and patients outcome

    DEFF Research Database (Denmark)

    Jensen, Søren Astrup; Vainer, Ben; Bartels, Annette

    2010-01-01

    To elucidate cellular features accountable for colorectal cancers' (CRC) capability to invade normal tissue and to metastasize, we investigated the level of the collagenase matrix metalloproteinase 9 (MMP-9) and its physiological inhibitor tissue inhibitor of metalloproteinases 1 (TIMP-1) in canc...

  10. Proteolytic cleavage and PKA phosphorylation of α1C subunit are not required for adrenergic regulation of CaV1.2 in the heart.

    Science.gov (United States)

    Katchman, Alexander; Yang, Lin; Zakharov, Sergey I; Kushner, Jared; Abrams, Jeffrey; Chen, Bi-Xing; Liu, Guoxia; Pitt, Geoffrey S; Colecraft, Henry M; Marx, Steven O

    2017-08-22

    Calcium influx through the voltage-dependent L-type calcium channel (Ca V 1.2) rapidly increases in the heart during "fight or flight" through activation of the β-adrenergic and protein kinase A (PKA) signaling pathway. The precise molecular mechanisms of β-adrenergic activation of cardiac Ca V 1.2, however, are incompletely known, but are presumed to require phosphorylation of residues in α 1C and C-terminal proteolytic cleavage of the α 1C subunit. We generated transgenic mice expressing an α 1C with alanine substitutions of all conserved serine or threonine, which is predicted to be a potential PKA phosphorylation site by at least one prediction tool, while sparing the residues previously shown to be phosphorylated but shown individually not to be required for β-adrenergic regulation of Ca V 1.2 current (17-mutant). A second line included these 17 putative sites plus the five previously identified phosphoregulatory sites (22-mutant), thus allowing us to query whether regulation requires their contribution in combination. We determined that acute β-adrenergic regulation does not require any combination of potential PKA phosphorylation sites conserved in human, guinea pig, rabbit, rat, and mouse α 1C subunits. We separately generated transgenic mice with inducible expression of proteolytic-resistant α 1C Prevention of C-terminal cleavage did not alter β-adrenergic stimulation of Ca V 1.2 in the heart. These studies definitively rule out a role for all conserved consensus PKA phosphorylation sites in α 1C in β-adrenergic stimulation of Ca V 1.2, and show that phosphoregulatory sites on α 1C are not redundant and do not each fractionally contribute to the net stimulatory effect of β-adrenergic stimulation. Further, proteolytic cleavage of α 1C is not required for β-adrenergic stimulation of Ca V 1.2.

  11. Effect of pyrimido[1,6-a]benzimidazoles, quinolones, and Ca2+ on the DNA gyrase-mediated cleavage reaction.

    Science.gov (United States)

    Gmünder, H; Kuratli, K; Keck, W

    1995-01-01

    The quinolones inhibit the A subunit of DNA gyrase in the presence of Mg2+ by interrupting the DNA breakage and resealing steps, and the latter step is also retarded without quinolones if Mg2+ is replaced by Ca2+. Pyrimido[1,6-a]benzimidazoles have been found to represent a new class of potent DNA gyrase inhibitors which also act at the A subunit. To determine alterations in the DNA sequence specificity of DNA gyrase for cleavage sites in the presence of inhibitors of both classes or in the presence of Ca2+, we used DNA restriction fragments of 164, 85, and 71 bp from the pBR322 plasmid as model substrates. Each contained, at a different position, the 20-bp pBR322 sequence around position 990, where DNA gyrase preferentially cleaves in the presence of quinolones. Our results show that pyrimido[1,6-a]benzimidazoles have a mode of action similar to that of quinolones; they inhibit the resealing step and influence the DNA sequence specificity of DNA gyrase in the same way. Differences between inhibitors of both classes could be observed only in the preferences of DNA gyrase for these cleavage sites. The 20-bp sequence appeared to have some properties that induced DNA gyrase to cleave all three DNA fragments in the presence of inhibitors within this sequence, whereas cleavage in the presence of Ca2+ was in addition dependent on the length of the DNA fragments. PMID:7695300

  12. Molecular Structures and Dynamics of the Stepwise Activation Mechanism of a Matrix Metalloproteinase Zymogen: Challenging the Cysteine Switch Dogma

    International Nuclear Information System (INIS)

    Rosenblum, G.; Meroueh, S.; Toth, M.; Fisher, J.; Fridman, R.; Mobashery, S.; Sagi, I.

    2007-01-01

    Activation of matrix metalloproteinase zymogen (pro-MMP) is a vital homeostatic process, yet its molecular basis remains unresolved. Using stopped-flow X-ray spectroscopy of the active site zinc ion, we determined the temporal sequence of pro-MMP-9 activation catalyzed by tissue kallikrein protease in milliseconds to several minutes. The identity of three intermediates seen by X-ray spectroscopy was corroborated by molecular dynamics simulations and quantum mechanics/molecular mechanics calculations. The cysteine-zinc interaction that maintains enzyme latency is disrupted via active-site proton transfers that mediate transient metal-protein coordination events and eventual binding of water. Unexpectedly, these events ensue as a direct result of complexation of pro-MMP-9 and kallikrein and occur before proteolysis and eventual dissociation of the pro-peptide from the catalytic site. Here we demonstrate the synergism among long-range protein conformational transitions, local structural rearrangements, and fine atomic events in the process of zymogen activation.

  13. Mechanisms of Vascular Damage by Hemorrhagic Snake Venom Metalloproteinases: Tissue Distribution and In Situ Hydrolysis

    Science.gov (United States)

    Baldo, Cristiani; Jamora, Colin; Yamanouye, Norma; Zorn, Telma M.; Moura-da-Silva, Ana M.

    2010-01-01

    Background Envenoming by viper snakes constitutes an important public health problem in Brazil and other developing countries. Local hemorrhage is an important symptom of these accidents and is correlated with the action of snake venom metalloproteinases (SVMPs). The degradation of vascular basement membrane has been proposed as a key event for the capillary vessel disruption. However, SVMPs that present similar catalytic activity towards extracellular matrix proteins differ in their hemorrhagic activity, suggesting that other mechanisms might be contributing to the accumulation of SVMPs at the snakebite area allowing capillary disruption. Methodology/Principal Findings In this work, we compared the tissue distribution and degradation of extracellular matrix proteins induced by jararhagin (highly hemorrhagic SVMP) and BnP1 (weakly hemorrhagic SVMP) using the mouse skin as experimental model. Jararhagin induced strong hemorrhage accompanied by hydrolysis of collagen fibers in the hypodermis and a marked degradation of type IV collagen at the vascular basement membrane. In contrast, BnP1 induced only a mild hemorrhage and did not disrupt collagen fibers or type IV collagen. Injection of Alexa488-labeled jararhagin revealed fluorescent staining around capillary vessels and co-localization with basement membrane type IV collagen. The same distribution pattern was detected with jararhagin-C (disintegrin-like/cysteine-rich domains of jararhagin). In opposition, BnP1 did not accumulate in the tissues. Conclusions/Significance These results show a particular tissue distribution of hemorrhagic toxins accumulating at the basement membrane. This probably occurs through binding to collagens, which are drastically hydrolyzed at the sites of hemorrhagic lesions. Toxin accumulation near blood vessels explains enhanced catalysis of basement membrane components, resulting in the strong hemorrhagic activity of SVMPs. This is a novel mechanism that underlies the difference between

  14. Functional analysis of coordinated cleavage in V(D)J recombination.

    Science.gov (United States)

    Kim, D R; Oettinger, M A

    1998-08-01

    V(D)J recombination in vivo requires a pair of signals with distinct spacer elements of 12 and 23 bp that separate conserved heptamer and nonamer motifs. Cleavage in vitro by the RAG1 and RAG2 proteins can occur at individual signals when the reaction buffer contains Mn2+, but cleavage is restricted to substrates containing two signals when Mg2+ is the divalent cation. By using a novel V(D)J cleavage substrate, we show that while the RAG proteins alone establish a moderate preference for a 12/23 pair versus a 12/12 pair, a much stricter dependence of cleavage on the 12/23 signal pair is produced by the inclusion of HMG1 and competitor double-stranded DNA. The competitor DNA serves to inhibit the cleavage of substrates carrying a 12/12 or 23/23 pair, as well as the cutting at individual signals in 12/23 substrates. We show that a 23/33 pair is more efficiently recombined than a 12/33 pair, suggesting that the 12/23 rule can be generalized to a requirement for spacers that differ from each other by a single helical turn. Furthermore, we suggest that a fixed spatial orientation of signals is required for cleavage. In general, the same signal variants that can be cleaved singly can function under conditions in which a signal pair is required. However, a chemically modified substrate with one noncleavable signal enables us to show that formation of a functional cleavage complex is mechanistically separable from the cleavage reaction itself and that although cleavage requires a pair of signals, cutting does not have to occur simultaneously at both. The implications of these results are discussed with respect to the mechanism of V(D)J recombination and the generation of chromosomal translocations.

  15. Remarkable weakness against cleavage stress for YBCO-coated conductors and its effect on the YBCO coil performance

    International Nuclear Information System (INIS)

    Yanagisawa, Y.; Nakagome, H.; Takematsu, T.; Takao, T.; Sato, N.; Takahashi, M.; Maeda, H.

    2011-01-01

    Cleavage strength for YBCO-coated conductor is extremely low, typically 0.5 MPa. The remarkable weakness is due to cracks on the slit edge of the conductor. The cleavage stress appears on YBCO double pancake coils impregnated with epoxy. The cleavage stress should be avoided in the coil winding. Cleavage strength for an YBCO-coated conductor at 77 K was investigated with a model experiment. The nominal cleavage strength for an YBCO-coated conductor is extremely low, typically 0.5 MPa. This low nominal cleavage strength is due to stress concentration on a small part of the YBCO-coated conductor in cleavage fracture. Debonding by the cleavage stress occurs at the interface between the buffer layer and the Hastelloy substrate. The nominal cleavage strength for a slit edge of the conductor is 2.5-times lower than that for the original edge of the conductor; cracks and micro-peel existing over the slit edge reduce the cleavage strength for the slit edge. Cleavage stress and peel stress should be avoided in coil winding, as they easily delaminate the YBCO-coated conductor, resulting in substantial degradation of coil performance. These problems are especially important for epoxy impregnated YBCO-coated conductor coils. It appears that effect of cleavage stress and peel stress are mostly negligible for paraffin impregnated YBCO-coated conductor coils or dry wound YBCO-coated conductor coils.

  16. Endocytic down-regulation of ErbB2 is stimulated by cleavage of its C-terminus

    DEFF Research Database (Denmark)

    Lerdrup, Mads; Bruun, Silas; Grandal, Michael Vibo

    2007-01-01

    inhibition of HSP90 with geldanamycin this cleavage is accompanied by proteasome-dependent endocytosis of ErbB2. However, it is unknown whether C-terminal cleavage is linked to endocytosis. To study ErbB2 cleavage and endocytic trafficking, we fused yellow fluorescent protein (YFP) and cyan fluorescent...

  17. Characterization of cleavage events in the multifunctional cilium adhesin Mhp684 (P146) reveals a mechanism by which Mycoplasma hyopneumoniae regulates surface topography.

    Science.gov (United States)

    Bogema, Daniel R; Deutscher, Ania T; Woolley, Lauren K; Seymour, Lisa M; Raymond, Benjamin B A; Tacchi, Jessica L; Padula, Matthew P; Dixon, Nicholas E; Minion, F Chris; Jenkins, Cheryl; Walker, Mark J; Djordjevic, Steven P

    2012-01-01

    Mycoplasma hyopneumoniae causes enormous economic losses to swine production worldwide by colonizing the ciliated epithelium in the porcine respiratory tract, resulting in widespread damage to the mucociliary escalator, prolonged inflammation, reduced weight gain, and secondary infections. Protein Mhp684 (P146) comprises 1,317 amino acids, and while the N-terminal 400 residues display significant sequence identity to the archetype cilium adhesin P97, the remainder of the molecule is novel and displays unusual motifs. Proteome analysis shows that P146 preprotein is endogenously cleaved into three major fragments identified here as P50(P146), P40(P146), and P85(P146) that reside on the cell surface. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) identified a semitryptic peptide that delineated a major cleavage site in Mhp684. Cleavage occurred at the phenylalanine residue within sequence (672)ATEF↓QQ(677), consistent with a cleavage motif resembling S/T-X-F↓X-D/E recently identified in Mhp683 and other P97/P102 family members. Biotinylated surface proteins recovered by avidin chromatography and separated by two-dimensional gel electrophoresis (2-D GE) showed that more-extensive endoproteolytic cleavage of P146 occurs. Recombinant fragments F1(P146)-F3(P146) that mimic P50(P146), P40(P146), and P85(P146) were constructed and shown to bind porcine epithelial cilia and biotinylated heparin with physiologically relevant affinity. Recombinant versions of F3(P146) generated from M. hyopneumoniae strain J and 232 sequences strongly bind porcine plasminogen, and the removal of their respective C-terminal lysine and arginine residues significantly reduces this interaction. These data reveal that P146 is an extensively processed, multifunctional adhesin of M. hyopneumoniae. Extensive cleavage coupled with variable cleavage efficiency provides a mechanism by which M. hyopneumoniae regulates protein topography. Vaccines used to control Mycoplasma

  18. Ku-mediated coupling of DNA cleavage and repair during programmed genome rearrangements in the ciliate Paramecium tetraurelia.

    Directory of Open Access Journals (Sweden)

    Antoine Marmignon

    2014-08-01

    Full Text Available During somatic differentiation, physiological DNA double-strand breaks (DSB can drive programmed genome rearrangements (PGR, during which DSB repair pathways are mobilized to safeguard genome integrity. Because of their unique nuclear dimorphism, ciliates are powerful unicellular eukaryotic models to study the mechanisms involved in PGR. At each sexual cycle, the germline nucleus is transmitted to the progeny, but the somatic nucleus, essential for gene expression, is destroyed and a new somatic nucleus differentiates from a copy of the germline nucleus. In Paramecium tetraurelia, the development of the somatic nucleus involves massive PGR, including the precise elimination of at least 45,000 germline sequences (Internal Eliminated Sequences, IES. IES excision proceeds through a cut-and-close mechanism: a domesticated transposase, PiggyMac, is essential for DNA cleavage, and DSB repair at excision sites involves the Ligase IV, a specific component of the non-homologous end-joining (NHEJ pathway. At the genome-wide level, a huge number of programmed DSBs must be repaired during this process to allow the assembly of functional somatic chromosomes. To understand how DNA cleavage and DSB repair are coordinated during PGR, we have focused on Ku, the earliest actor of NHEJ-mediated repair. Two Ku70 and three Ku80 paralogs are encoded in the genome of P. tetraurelia: Ku70a and Ku80c are produced during sexual processes and localize specifically in the developing new somatic nucleus. Using RNA interference, we show that the development-specific Ku70/Ku80c heterodimer is essential for the recovery of a functional somatic nucleus. Strikingly, at the molecular level, PiggyMac-dependent DNA cleavage is abolished at IES boundaries in cells depleted for Ku80c, resulting in IES retention in the somatic genome. PiggyMac and Ku70a/Ku80c co-purify as a complex when overproduced in a heterologous system. We conclude that Ku has been integrated in the Paramecium

  19. Subcellular RNA profiling links splicing and nuclear DICER1 to alternative cleavage and polyadenylation.

    Science.gov (United States)

    Neve, Jonathan; Burger, Kaspar; Li, Wencheng; Hoque, Mainul; Patel, Radhika; Tian, Bin; Gullerova, Monika; Furger, Andre

    2016-01-01

    Alternative cleavage and polyadenylation (APA) plays a crucial role in the regulation of gene expression across eukaryotes. Although APA is extensively studied, its regulation within cellular compartments and its physiological impact remains largely enigmatic. Here, we used a rigorous subcellular fractionation approach to compare APA profiles of cytoplasmic and nuclear RNA fractions from human cell lines. This approach allowed us to extract APA isoforms that are subjected to differential regulation and provided us with a platform to interrogate the molecular regulatory pathways that shape APA profiles in different subcellular locations. Here, we show that APA isoforms with shorter 3' UTRs tend to be overrepresented in the cytoplasm and appear to be cell-type-specific events. Nuclear retention of longer APA isoforms occurs and is partly a result of incomplete splicing contributing to the observed cytoplasmic bias of transcripts with shorter 3' UTRs. We demonstrate that the endoribonuclease III, DICER1, contributes to the establishment of subcellular APA profiles not only by expected cytoplasmic miRNA-mediated destabilization of APA mRNA isoforms, but also by affecting polyadenylation site choice. © 2016 Neve et al.; Published by Cold Spring Harbor Laboratory Press.

  20. Genetic stability of attenuated mengovirus vectors with duplicate primary cleavage sequences

    International Nuclear Information System (INIS)

    Binder, J.J.; Hoffman, M.A.; Palmenberg, A.C.

    2003-01-01

    Short poly(C)-tract Mengoviruses have proven vaccine efficacy in many species of animals. A novel vector for the delivery of foreign proteins was created by insertion of a second autoproteolytic primary cleavage cassette linked to a multiple cloning site (MCS) into an attenuated variant of Mengo. Nineteen cDNAs from foreign sequences that ranged from 39 to 1653 bases were cloned into the MCS. The viral reading frame was maintained and translation resulted in dual, autocatalytic excision of the foreign peptides without disruption of any Mengo proteins. All cDNAs except those with the largest insertions produced viable virus. Active proteins such as GFP, CAT, and SIV p27 were expressed within infected cells. Relative to parental Mengo, the growth kinetics and genetic stability of each vector was inversely proportional to the size of the inserted sequence. While segments up to 1000 bases could be carried, inserts greater than 500-600 bases were usually reduced in size during serial passage. The limit on carrying capacity was probably due to difficulties in virion assembly or particle stability. Yet for inserts less than 500-600 bases, the Mengo vectors provided an effective system for the delivery of foreign epitopes into cells and mice

  1. Covalent bond force profile and cleavage in a single polymer chain

    Science.gov (United States)

    Garnier, Lionel; Gauthier-Manuel, Bernard; van der Vegte, Eric W.; Snijders, Jaap; Hadziioannou, Georges

    2000-08-01

    We present here the measurement of the single-polymer entropic elasticity and the single covalent bond force profile, probed with two types of atomic force microscopes (AFM) on a synthetic polymer molecule: polymethacrylic acid in water. The conventional AFM allowed us to distinguish two types of interactions present in this system when doing force spectroscopic measurements: the first interaction is associated with adsorption sites of the polymer chains onto a bare gold surface, the second interaction is directly correlated to the rupture process of a single covalent bond. All these bridging interactions allowed us to stretch the single polymer chain and to determine the various factors playing a role in the elasticity of these molecules. To obtain a closer insight into the bond rupture process, we moved to a force sensor stable in position when measuring attractive forces. By optimizing the polymer length so as to fulfill the elastic stability conditions, we were able for the first time to map out the entire force profile associated with the cleavage of a single covalent bond. Experimental data coupled with molecular quantum mechanical calculations strongly suggest that the breaking bond is located at one end of the polymer chain.

  2. Synthesis, characterization, anti-microbial, DNA binding and cleavage studies of Schiff base metal complexes

    Directory of Open Access Journals (Sweden)

    Poomalai Jayaseelan

    2016-09-01

    Full Text Available A novel Schiff base ligand has been prepared by the condensation between butanedione monoxime with 3,3′-diaminobenzidine. The ligand and metal complexes have been characterized by elemental analysis, UV, IR, 1H NMR, conductivity measurements, EPR and magnetic studies. The molar conductance studies of Cu(II, Ni(II, Co(II and Mn(II complexes showed non-electrolyte in nature. The ligand acts as dibasic with two N4-tetradentate sites and can coordinate with two metal ions to form binuclear complexes. The spectroscopic data of metal complexes indicated that the metal ions are complexed with azomethine nitrogen and oxyimino nitrogen atoms. The binuclear metal complexes exhibit octahedral arrangements. DNA binding properties of copper(II metal complex have been investigated by electronic absorption spectroscopy. Results suggest that the copper(II complex bind to DNA via an intercalation binding mode. The nucleolytic cleavage activities of the ligand and their complexes were assayed on CT-DNA using gel electrophoresis in the presence and absence of H2O2. The ligand showed increased nuclease activity when administered as copper complex and copper(II complex behave as efficient chemical nucleases with hydrogen peroxide activation. The anti-microbial activities and thermal studies have also been studied. In anti-microbial activity all complexes showed good anti-microbial activity higher than ligand against gram positive, gram negative bacteria and fungi.

  3. Chromosome fragility at FRAXA in human cleavage stage embryos at risk for fragile X syndrome.

    Science.gov (United States)

    Verdyck, Pieter; Berckmoes, Veerle; De Vos, Anick; Verpoest, Willem; Liebaers, Inge; Bonduelle, Maryse; De Rycke, Martine

    2015-10-01

    Fragile X syndrome (FXS), the most common inherited intellectual disability syndrome, is caused by expansion and hypermethylation of the CGG repeat in the 5' UTR of the FMR1 gene. This expanded repeat, also known as the rare fragile site FRAXA, causes X chromosome fragility in cultured cells from patients but only when induced by perturbing pyrimidine synthesis. We performed preimplantation genetic diagnosis (PGD) on 595 blastomeres biopsied from 442 cleavage stage embryos at risk for FXS using short tandem repeat (STR) markers. In six blastomeres, from five embryos an incomplete haplotype was observed with loss of all alleles telomeric to the CGG repeat. In all five embryos, the incomplete haplotype corresponded to the haplotype carrying the CGG repeat expansion. Subsequent analysis of additional blastomeres from three embryos by array comparative genomic hybridization (aCGH) confirmed the presence of a terminal deletion with a breakpoint close to the CGG repeat in two blastomeres from one embryo. A blastomere from another embryo showed the complementary duplication. We conclude that a CGG repeat expansion at FRAXA causes X chromosome fragility in early human IVF embryos at risk for FXS. © 2015 Wiley Periodicals, Inc.

  4. Metastasis is strongly reduced by the matrix metalloproteinase inhibitor Galardin in the MMTV-PymT transgenic breast cancer model

    DEFF Research Database (Denmark)

    Almholt, Kasper; Juncker-Jensen, Anna; Lærum, Ole Didrik

    2008-01-01

    Matrix metalloproteinases (MMP) have several roles that influence cancer progression and dissemination. However, low molecular weight metalloproteinase inhibitors (MPI) have not yet been tested in transgenic/spontaneous metastasis models. We have tested Galardin/GM6001, a potent MPI that reacts w...

  5. Evidence of Reduced CBG Cleavage in Abdominal Obesity: A Potential Factor in Development of the Metabolic Syndrome.

    Science.gov (United States)

    Nenke, M A; Lewis, J G; Rankin, W; Torpy, D J

    2016-08-01

    Corticosteroid-binding globulin (CBG) is involved in the regulation of cortisol delivery. Neutrophil elastase-mediated cleavage of high to low affinity CBG (haCBG to laCBG) induces cortisol release at inflammatory sites. Past studies have shown reduced CBG in obesity, an inflammatory state, particularly in central adiposity/metabolic syndrome. We performed an observational, cross-sectional study of the effects of obesity, age and sex on ha/laCBG in 100 healthy volunteers. Total and haCBG levels were 11% higher in women but did not vary with age or menopausal status. Total CBG levels were lower with increased body weight and waist circumference; laCBG levels were lower with increased body weight, waist circumference, body mass index and body fat; higher haCBG levels were seen with increased body fat. The relation between CBG and adiposity appeared to be driven predominantly by the metabolic syndrome group. The results suggest reduced CBG cleavage in central obesity, possibly contributing to the characteristic inflammatory phenotype of the central obesity and metabolic syndrome. The mechanism of gender differences in CBG levels is unclear. © Georg Thieme Verlag KG Stuttgart · New York.

  6. Alanine substitutions in the GXXXG motif alter C99 cleavage by γ-secretase but not its dimerization.

    Science.gov (United States)

    Higashide, Hidekazu; Ishihara, Seiko; Nobuhara, Mika; Ihara, Yasuo; Funamoto, Satoru

    2017-03-01

    The amyloid β (Aβ) protein is a major component of senile plaques, one of the neuropathological hallmarks of Alzheimer's disease. Amyloidogenic processing of amyloid precursor protein (APP) by β- and γ-secretases leads to production of Aβ. APP contains tandem triple repeats of the GXXXG motif in its extracellular juxtamembrane and transmembrane regions. It is reported that the GXXXG motif is related to protein-protein interactions, but it remains controversial whether the GXXXG motif in APP is involved in substrate dimerization and whether dimerization affects γ-secretase-dependent cleavage. Therefore, the relationship between the GXXXG motifs, substrate dimerization, and γ-secretase-dependent cleavage sites remains unclear. Here, we applied blue native poly acrylamide gel electrophoresis to examine the effect of alanine substitutions within the GXXXG motifs of APP carboxyl terminal fragment (C99) on its dimerization and Aβ production. Surprisingly, alanine substitutions in the motif failed to alter C99 dimerization in detergent soluble state. Cell-based and solubilized γ-secretase assays demonstrated that increasing alanine substitutions in the motif tended to decrease long Aβ species such as Aβ42 and Aβ43 and to increase in short Aβ species concomitantly. Our data suggest that the GXXXG motif is crucial for Aβ production, but not for C99 dimerization. © 2016 International Society for Neurochemistry.

  7. RISC-interacting clearing 3'- 5' exoribonucleases (RICEs) degrade uridylated cleavage fragments to maintain functional RISC in Arabidopsis thaliana.

    Science.gov (United States)

    Zhang, Zhonghui; Hu, Fuqu; Sung, Min Woo; Shu, Chang; Castillo-González, Claudia; Koiwa, Hisashi; Tang, Guiliang; Dickman, Martin; Li, Pingwei; Zhang, Xiuren

    2017-05-02

    RNA-induced silencing complex (RISC) is composed of miRNAs and AGO proteins. AGOs use miRNAs as guides to slice target mRNAs to produce truncated 5' and 3' RNA fragments. The 5' cleaved RNA fragments are marked with uridylation for degradation. Here, we identified novel cofactors of Arabidopsis AGOs, named RICE1 and RICE2. RICE proteins specifically degraded single-strand (ss) RNAs in vitro; but neither miRNAs nor miRNA*s in vivo. RICE1 exhibited a DnaQ-like exonuclease fold and formed a homohexamer with the active sites located at the interfaces between RICE1 subunits. Notably, ectopic expression of catalytically-inactive RICE1 not only significantly reduced miRNA levels; but also increased 5' cleavage RISC fragments with extended uridine tails. We conclude that RICEs act to degrade uridylated 5' products of AGO cleavage to maintain functional RISC. Our study also suggests a possible link between decay of cleaved target mRNAs and miRNA stability in RISC.

  8. Role of Matrix Metalloproteinase-2, Matrix Metalloproteinase-9, and Vascular Endothelial Growth Factor in the Development of Chronic Subdural Hematoma

    Science.gov (United States)

    Hua, Cong; Feng, Yan; Yuan, Hongyan; Song, Hongmei

    2016-01-01

    Abstract Chronic subdural hematoma (CSDH) is an inflammatory and angiogenic disease. Vascular endothelial growth factor (VEGF) has an important effect on the pathological progression of CSDH. The matrix metalloproteinases (MMPs) and VEGF also play a significant role in pathological angiogenesis. Our research was to investigate the level of MMPs and VEGF in serum and hematoma fluid. Magnetic Resonance Imaging (MRI) shows the characteristics of different stages of CSDH. We also analyzed the relationship between the level of VEGF in subdural hematoma fluid and the appearances of the patients' MRI. We performed a study comparing serum and hematoma fluid in 37 consecutive patients with primary CSDHs using enzyme-linked immunosorbent assay (ELISA). MMP-2 and MMP-9 activity was assayed by the gelatin zymography method. The patients were divided into five groups according to the appearance of the hematomas on MRI: group 1 (T1-weighted low, T2-weighted low, n=4), group 2 (T1-weighted high, T2-weighted low, n=11), group 3 (T1-weighted mixed, T2-weighted mixed, n=9), group 4 (T1-weighted high, T2-weighted high, n=5), and group 5 (T1-weighted low, T2-weighted high, n=8). Neurological status was assessed by Markwalder score on admission and at follow-up. The mean age, sex, and Markwalder score were not significantly different among groups. The mean concentration of VEGF, MMP-2, and MMP-9 were significantly higher in hematoma fluid than in serum (phematoma fluid (phematoma fluid (phematoma fluid, suggesting that the MMPs/VEGF system may be involved in the angiogenesis of CSDH. We also demonstrate a significant correlation between the concentrations of VEGF and MRI appearance. This finding supports the hypothesis that high VEGF concentration in the hematoma fluid is of major pathophysiological importance in the generation and steady increase of the hematoma volume, as well as the determination of MRI appearance. PMID:25646653

  9. Matrix metalloproteinase-12 gene regulation by a PPAR alpha agonist in human monocyte-derived macrophages

    International Nuclear Information System (INIS)

    Souissi, Imen Jguirim; Billiet, Ludivine; Cuaz-Perolin, Clarisse; Slimane, Mohamed-Naceur; Rouis, Mustapha

    2008-01-01

    MMP-12, a macrophage-specific matrix metalloproteinase with large substrate specificity, has been reported to be highly expressed in mice, rabbits and human atherosclerotic lesions. Increased MMP-12 from inflammatory macrophages is associated with several degenerative diseases such as atherosclerosis. In this manuscript, we show that IL-1β, a proinflammatory cytokine found in atherosclerotic plaques, increases both mRNA and protein levels of MMP-12 in human monocyte-derived macrophages (HMDM). Since peroxisome proliferator-activated receptors (PPARs), such as PPARα and PPARγ, are expressed in macrophages and because PPAR activation exerts an anti-inflammatory effect on vascular cells, we have investigated the effect of PPARα and γ isoforms on MMP-12 regulation in HMDM. Our results show that MMP-12 expression (mRNA and protein) is down regulated in IL-1β-treated macrophages only in the presence of a specific PPARα agonist, GW647, in a dose-dependent manner. In contrast, this inhibitory effect was abolished in IL-1β-stimulated peritoneal macrophages isolated from PPARα -/- mice and treated with the PPARα agonist, GW647. Moreover, reporter gene transfection experiments using different MMP-12 promoter constructs showed a reduction of the promoter activities by ∼ 50% in IL-1β-stimulated PPARα-pre-treated cells. However, MMP-12 promoter analysis did not reveal the presence of a PPRE response element. The IL-1β effect is known to be mediated through the AP-1 binding site. Mutation of the AP-1 site, located at - 81 in the MMP-12 promoter region relative to the transcription start site, followed by transfection analysis, gel shift and ChIP experiments revealed that the inhibitory effect was the consequence of the protein-protein interaction between GW 647-activated PPARα and c-Fos or c-Jun transcription factors, leading to inhibition of their binding to the AP-1 motif. These studies suggest that PPARα agonists may be used therapeutically, not only for lipid

  10. Dynamic propagation and cleavage crack arrest in bainitic steel

    International Nuclear Information System (INIS)

    Hajjaj, M.

    2006-06-01

    In complement of the studies of harmfulness of defects, generally realized in term of initiation, the concept of crack arrest could be used as complementary analyses to the studies of safety. The stop occurs when the stress intensity factor becomes lower than crack arrest toughness (KIa) calculated in elasto-statics (KI ≤ KIa). The aim of this thesis is to understand and predict the stop of a crack propagating at high speed in a 18MND5 steel used in the pressure water reactor (PWR). The test chosen to study crack arrest is the disc thermal shock test. The observations under the scanning electron microscope of the fracture surface showed that the crack arrest always occurs in cleavage mode and that the critical microstructural entity with respect to the propagation and crack arrest corresponds to at least the size of the prior austenitic grain. The numerical analyses in elasto-statics confirm the conservatism of the codified curve of the RCC-M with respect to the values of KIa. The dynamic numerical analyses show that the deceleration of the crack measured at the end of the propagation is related to the global dynamic of the structure (vibrations). The transferability to components of crack arrest toughness obtained from tests analysed in static is thus not assured. The disc thermal shock tests were also modelled by considering a criterion of propagation and arrest of the type 'RKR' characterized by a critical stress sc which depends on the temperature. The results obtained account well for the crack jump measured in experiments as well as the shape of the crack arrest front. (author)

  11. Essential role of cyclophilin A for hepatitis C virus replication and virus production and possible link to polyprotein cleavage kinetics.

    Directory of Open Access Journals (Sweden)

    Artur Kaul

    2009-08-01

    Full Text Available Viruses are obligate intracellular parasites and therefore their replication completely depends on host cell factors. In case of the hepatitis C virus (HCV, a positive-strand RNA virus that in the majority of infections establishes persistence, cyclophilins are considered to play an important role in RNA replication. Subsequent to the observation that cyclosporines, known to sequester cyclophilins by direct binding, profoundly block HCV replication in cultured human hepatoma cells, conflicting results were obtained as to the particular cyclophilin (Cyp required for viral RNA replication and the underlying possible mode of action. By using a set of cell lines with stable knock-down of CypA or CypB, we demonstrate in the present work that replication of subgenomic HCV replicons of different genotypes is reduced by CypA depletion up to 1,000-fold whereas knock-down of CypB had no effect. Inhibition of replication was rescued by over-expression of wild type CypA, but not by a mutant lacking isomerase activity. Replication of JFH1-derived full length genomes was even more sensitive to CypA depletion as compared to subgenomic replicons and virus production was completely blocked. These results argue that CypA may target an additional viral factor outside of the minimal replicase contributing to RNA amplification and assembly, presumably nonstructural protein 2. By selecting for resistance against the cyclosporine analogue DEBIO-025 that targets CypA in a dose-dependent manner, we identified two mutations (V2440A and V2440L close to the cleavage site between nonstructural protein 5A and the RNA-dependent RNA polymerase in nonstructural protein 5B that slow down cleavage kinetics at this site and reduce CypA dependence of viral replication. Further amino acid substitutions at the same cleavage site accelerating processing increase CypA dependence. Our results thus identify an unexpected correlation between HCV polyprotein processing and CypA dependence

  12. Essential role of cyclophilin A for hepatitis C virus replication and virus production and possible link to polyprotein cleavage kinetics.

    Science.gov (United States)

    Kaul, Artur; Stauffer, Sarah; Berger, Carola; Pertel, Thomas; Schmitt, Jennifer; Kallis, Stephanie; Zayas, Margarita; Lopez, Margarita Zayas; Lohmann, Volker; Luban, Jeremy; Bartenschlager, Ralf

    2009-08-01

    Viruses are obligate intracellular parasites and therefore their replication completely depends on host cell factors. In case of the hepatitis C virus (HCV), a positive-strand RNA virus that in the majority of infections establishes persistence, cyclophilins are considered to play an important role in RNA replication. Subsequent to the observation that cyclosporines, known to sequester cyclophilins by direct binding, profoundly block HCV replication in cultured human hepatoma cells, conflicting results were obtained as to the particular cyclophilin (Cyp) required for viral RNA replication and the underlying possible mode of action. By using a set of cell lines with stable knock-down of CypA or CypB, we demonstrate in the present work that replication of subgenomic HCV replicons of different genotypes is reduced by CypA depletion up to 1,000-fold whereas knock-down of CypB had no effect. Inhibition of replication was rescued by over-expression of wild type CypA, but not by a mutant lacking isomerase activity. Replication of JFH1-derived full length genomes was even more sensitive to CypA depletion as compared to subgenomic replicons and virus production was completely blocked. These results argue that CypA may target an additional viral factor outside of the minimal replicase contributing to RNA amplification and assembly, presumably nonstructural protein 2. By selecting for resistance against the cyclosporine analogue DEBIO-025 that targets CypA in a dose-dependent manner, we identified two mutations (V2440A and V2440L) close to the cleavage site between nonstructural protein 5A and the RNA-dependent RNA polymerase in nonstructural protein 5B that slow down cleavage kinetics at this site and reduce CypA dependence of viral replication. Further amino acid substitutions at the same cleavage site accelerating processing increase CypA dependence. Our results thus identify an unexpected correlation between HCV polyprotein processing and CypA dependence of HCV

  13. Matrix metalloproteinases (MMPs) in the endometrium of bitches.

    Science.gov (United States)

    Chu Py, Po-yin; Salamonsen, L A; Lee, C S; Wright, P J

    2002-03-01

    The relationships between activities of matrix metalloproteinases (MMPs) in the canine uterus and the occurrence of degeneration of the luminal epithelium, cystic endometrial hyperplasia, pyometra and uterine remodelling post partum were determined. Mature bitches (n = 10) were ovariectomized, treated with hormones (oestradiol benzoate, progestagen) and investigated at stages simulating pro-oestrus (n = 2), oestrus (n = 2), dioestrus (n = 2), and mid- (n = 2) and late (n = 2) anoestrus (3 and 9 weeks, respectively, after cessation of treatment with progestagen). Untreated bitches (n = 1 per group) served as controls (Expt 1). An additional 10 ovariectomized bitches, at the end of treatment-induced simulated dioestrus, were treated each day for a further 3 weeks either with the same dose (standard dose, n = 3), a decreased dose (n = 3) or an increased dose (n = 3) of progestagen, or no treatment (withdrawal dose, n = 1). These bitches were then investigated (Expt 2). A suture was placed in the lumen of one uterine horn of another five bitches at ovariectomy. Three of these bitches were treated to induce simulated dioestrus and two bitches served as untreated controls. In the hormone-treated bitches, the suture resulted in cystic endometrial hyperplasia in one bitch and in cystic endometrial hyperplasia with pyometra in two bitches. The control bitches showed no cystic endometrial hyperplasia or pyometra (Expt 3). Four intact bitches were studied at 2 (n = 1), 3 (n = 2) and 11 (n = 1) weeks post partum. Uterine tissues were also collected from two bitches with naturally occurring cystic endometrial hyperplasia with pyometra (Expt 4). All uteri were examined histologically and the activities of MMP-2, -7 and -9 (latent and active forms) were assessed using zymography of extracts of endometrium. In Expts 1 and 2, marked degeneration of the luminal epithelium in six of 25 bitches (simulated mid-anoestrus, withdrawal dose and decreased dose groups) was not associated

  14. Structure-function analysis of Staphylococcus aureus amidase reveals the determinants of peptidoglycan recognition and cleavage.

    Science.gov (United States)

    Büttner, Felix Michael; Zoll, Sebastian; Nega, Mulugeta; Götz, Friedrich; Stehle, Thilo

    2014-04-18

    The bifunctional major autolysin AtlA of Staphylococcus aureus cleaves the bacterium's peptidoglycan network (PGN) at two distinct sites during cell division. Deletion of the enzyme results in large cell clusters with disordered division patterns, indicating that AtlA could be a promising target for the development of new antibiotics. One of the two functions of AtlA is performed by the N-acetylmuramyl-l-alanine amidase AmiA, which cleaves the bond between the carbohydrate and the peptide moieties of PGN. To establish the structural requirements of PGN recognition and the enzymatic mechanism of cleavage, we solved the crystal structure of the catalytic domain of AmiA (AmiA-cat) in complex with a peptidoglycan-derived ligand at 1.55 Å resolution. The peptide stem is clearly visible in the structure, forming extensive contacts with protein residues by docking into an elongated groove. Less well defined electron density and the analysis of surface features indicate likely positions of the carbohydrate backbone and the pentaglycine bridge. Substrate specificity analysis supports the importance of the pentaglycine bridge for fitting into the binding cleft of AmiA-cat. PGN of S. aureus with l-lysine tethered with d-alanine via a pentaglycine bridge is completely hydrolyzed, whereas PGN of Bacillus subtilis with meso-diaminopimelic acid directly tethered with d-alanine is not hydrolyzed. An active site mutant, H370A, of AmiA-cat was completely inactive, providing further support for the proposed catalytic mechanism of AmiA. The structure reported here is not only the first of any bacterial amidase in which both the PGN component and the water molecule that carries out the nucleophilic attack on the carbonyl carbon of the scissile bond are present; it is also the first peptidoglycan amidase complex structure of an important human pathogen.

  15. Patterns of proteolytic cleavage and carbodiimide derivatization in sarcoplasmic reticulum adenosinetriphosphatase

    International Nuclear Information System (INIS)

    de Ancos, J.G.; Inesi, G.

    1988-01-01

    Two series of experiments were carried out to characterize (a) peptide fragments of sarcoplasmic reticulum (SR) ATPase, based on proteolysis with different enzymes and distribution of known labels, and (b) specific labeling and functional inactivation patterns, following ATPase derivatization with dicyclohexylcarbodiimide (DCCD) under various conditions. Digestion with trypsin or chymotrypsin results in the initial cleavage of the SR ATPase in two fragments of similar size and then into smaller fragments, while subtilisin and thermolysin immediately yield smaller fragments. Peptide fragments were assigned to segments of the protein primary structure and to functionally relevant domains, such as those containing the 32 P at the active site and the fluorescein isothiocyanate at the nucleotide site. ATPase derivatization with [ 14 C]DCCD under mild conditions produced selective inhibition of ATPase hydrolytic catalysis without significant incorporation of the 14 C radioactive label. This effect is attributed to blockage of catalytically active residues by reaction of the initial DCCD adduct with endogenous or exogenous nucleophiles. ATPase derivatization with [ 14 C]DCCD under more drastic conditions produced inhibition of calcium binding, 14 C radioactive labeling of tryptic fragments A 1 and A 2 (but not of B), and extensive cross-linking. The presence of calcium during derivatization prevented functional inactivation, radioactive labeling of fragment A 2 , and internal cross-linking of fragment A 1 . It is proposed that both A 1 and A 2 fragments participate in formation of the calcium binding domain and that the labeled residues of fragment A 2 are directly involved in calcium complexation. A diagram is constructed, representing the relative positions of labels and functional domains within the ATPase protein

  16. Structure-Function Analysis of Staphylococcus aureus Amidase Reveals the Determinants of Peptidoglycan Recognition and Cleavage*

    Science.gov (United States)

    Büttner, Felix Michael; Zoll, Sebastian; Nega, Mulugeta; Götz, Friedrich; Stehle, Thilo

    2014-01-01

    The bifunctional major autolysin AtlA of Staphylococcus aureus cleaves the bacterium's peptidoglycan network (PGN) at two distinct sites during cell division. Deletion of the enzyme results in large cell clusters with disordered division patterns, indicating that AtlA could be a promising target for the development of new antibiotics. One of the two functions of AtlA is performed by the N-acetylmuramyl-l-alanine amidase AmiA, which cleaves the bond between the carbohydrate and the peptide moieties of PGN. To establish the structural requirements of PGN recognition and the enzymatic mechanism of cleavage, we solved the crystal structure of the catalytic domain of AmiA (AmiA-cat) in complex with a peptidoglycan-derived ligand at 1.55 Å resolution. The peptide stem is clearly visible in the structure, forming extensive contacts with protein residues by docking into an elongated groove. Less well defined electron density and the analysis of surface features indicate likely positions of the carbohydrate backbone and the pentaglycine bridge. Substrate specificity analysis supports the importance of the pentaglycine bridge for fitting into the binding cleft of AmiA-cat. PGN of S. aureus with l-lysine tethered with d-alanine via a pentaglycine bridge is completely hydrolyzed, whereas PGN of Bacillus subtilis with meso-diaminopimelic acid directly tethered with d-alanine is not hydrolyzed. An active site mutant, H370A, of AmiA-cat was completely inactive, providing further support for the proposed catalytic mechanism of AmiA. The structure reported here is not only the first of any bacterial amidase in which both the PGN component and the water molecule that carries out the nucleophilic attack on the carbonyl carbon of the scissile bond are present; it is also the first peptidoglycan amidase complex structure of an important human pathogen. PMID:24599952

  17. HPLC-MS/MS method optimisation for matrix metalloproteinase 3 and matrix metalloproteinase 9 determination in human blood serum using target analysis.

    Science.gov (United States)

    Kotnik, Petra; Krajnc, Metka Koren; Pahor, Artur; Finšgar, Matjaž; Knez, Željko

    2018-02-20

    A quantitative analysis of zinc endopeptidases matrix metalloproteinase 9 (MMP9) and matrix metalloproteinase 3 (MMP3) from human blood serum are presented. Both matrix metalloproteinases (MMP) are present in human blood serum and can be used as biomarkers for different diseases. The analysis was performed using LC-MS/MS with a triple quadrupole mass spectrometer, based on two specific peptides of each MMP in comparison with an enzyme-linked immunosorbent assay (ELISA). While the conditions for the LC-MS/MS analysis of MMP9 peptides were previously reported for bronchoalveolar lavage fluid, the analysis of MMP3 peptides was newly quantified for human blood serum herein for the first time. For MMP3, the linear behaviour was determined in the concentration range from 1.0-200.0ng/mL (R 2 =0.997) with an LLOD of 0.5ng/mL. For MMP9, linearity was determined in the concentration range from 6.5-65.0ng/mL (R 2 =0.995) with an LLOD of 2.0ng/mL. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Changes in Contact Area in Meniscus Horizontal Cleavage Tears Subjected to Repair and Resection.

    Science.gov (United States)

    Beamer, Brandon S; Walley, Kempland C; Okajima, Stephen; Manoukian, Ohan S; Perez-Viloria, Miguel; DeAngelis, Joseph P; Ramappa, Arun J; Nazarian, Ara

    2017-03-01

    To assess the changes in tibiofemoral contact pressure and contact area in human knees with a horizontal cleavage tear before and after treatment. Ten human cadaveric knees were tested. Pressure sensors were placed under the medial meniscus and the knees were loaded at twice the body weight for 20 cycles at 0°, 10°, and 20° of flexion. Contact area and pressure were recorded for the intact meniscus, the meniscus with a horizontal cleavage tear, after meniscal repair, after partial meniscectomy (single leaflet), and after subtotal meniscectomy (double leaflet). The presence of a horizontal cleavage tear significantly increased average peak contact pressure and reduced effective average tibiofemoral contact area at all flexion angles tested compared with the intact state (P contact pressure after creation of the horizontal cleavage tear. Repairing the horizontal cleavage tear restored peak contact pressures and areas to within 15% of baseline, statistically similar to the intact state at all angles tested (P contact pressure and reduced average contact area at all degrees of flexion compared with the intact state (P contact area and a significant elevation in contact pressure. These changes may accelerate joint degeneration. A suture-based repair of these horizontal cleavage tears returns the contact area and contact pressure to nearly normal, whereas both partial and subtotal meniscectomy lead to significant reductions in contact area and significant elevations in contact pressure within the knee. Repairing horizontal cleavage tears may lead to improved clinical outcomes by preserving meniscal tissue and the meniscal function. Understanding contact area and peak contact pressure resulting from differing strategies for treating horizontal cleavage tears will allow the surgeon to evaluate the best strategy for treating his or her patients who present with this meniscal pathology. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier

  19. Control of extracellular cleavage of ProBDNF by high frequency neuronal activity

    OpenAIRE

    Nagappan, Guhan; Zaitsev, Eugene; Senatorov, Vladimir V.; Yang, Jianmin; Hempstead, Barbara L.; Lu, Bai

    2009-01-01

    Pro- and mature neurotrophins often elicit opposing biological effects. For example, mature brain-derived neurotrophic factor (mBDNF) is critical for long-term potentiation induced by high-frequency stimulation, whereas proBDNF facilitate long-term depression induced by low-frequency stimulation. Because mBDNF is derived from proBDNF by endoproteolytic cleavage, mechanisms regulating the cleavage of proBDNF may control the direction of BDNF regulation. Using methods that selectively detect pr...

  20. Condensed tannins: A novel rearrangement of procyanidins and prodelphinidins in thiolytic cleavage

    Science.gov (United States)

    G. Wayne McGraw; Jan P. Steynberg; Richard W. Hemingway

    1993-01-01

    Conditions commonly used for the thiolytic cleavage of interflavanoid bonds of condensed tannins also result in cleavage of the C4 to C10 bond of flavan units. Subsequenet lectrophilic attack of the C4 carbocation on the C2' or C6' of the B-ring, and loss of phloroglucinol (the A-ring), result in the formation of a mixture of 1,3-dithiobenzyl-2,4,s,6-...

  1. Structural and Biochemical Characterization of Organotin and Organolead Compounds Binding to the Organomercurial Lyase MerB Provide New Insights into Its Mechanism of Carbon–Metal Bond Cleavage

    Energy Technology Data Exchange (ETDEWEB)

    Wahba, Haytham M. [Département; Faculty; Stevenson, Michael J. [Department; Mansour, Ahmed [Département; Sygusch, Jurgen [Département; Wilcox, Dean E. [Department; Omichinski, James G. [Département

    2017-01-03

    The organomercurial lyase MerB has the unique ability to cleave carbon–Hg bonds, and structural studies indicate that three residues in the active site (C96, D99, and C159 in E. coli MerB) play important roles in the carbon–Hg bond cleavage. However, the role of each residue in carbon–metal bond cleavage has not been well-defined. To do so, we have structurally and biophysically characterized the interaction of MerB with a series of organotin and organolead compounds. Studies with two known inhibitors of MerB, dimethyltin (DMT) and triethyltin (TET), reveal that they inhibit by different mechanisms. In both cases the initial binding is to D99, but DMT subsequently binds to C96, which induces a conformation change in the active site. In contrast, diethyltin (DET) is a substrate for MerB and the SnIV product remains bound in the active site in a coordination similar to that of HgII following cleavage of organomercurial compounds. The results with analogous organolead compounds are similar in that trimethyllead (TML) is not cleaved and binds only to D99, whereas diethyllead (DEL) is a substrate and the PbIV product remains bound in the active site. Binding and cleavage is an exothermic reaction, while binding to D99 has negligible net heat flow. These results show that initial binding of organometallic compounds to MerB occurs at D99 followed, in some cases, by cleavage and loss of the organic moieties and binding of the metal ion product to C96, D99, and C159. The N-terminus of MerA is able to extract the bound PbVI but not the bound SnIV. These results suggest that MerB could be utilized for bioremediation applications, but certain organolead and organotin compounds may present an obstacle by inhibiting the enzyme.

  2. In vivo imaging of membrane type-1 matrix metalloproteinase with a novel activatable near-infrared fluorescence probe.

    Science.gov (United States)

    Shimizu, Yoichi; Temma, Takashi; Hara, Isao; Makino, Akira; Kondo, Naoya; Ozeki, Ei-Ichi; Ono, Masahiro; Saji, Hideo

    2014-08-01

    Membrane type-1 matrix metalloproteinase (MT1-MMP) is a protease activating MMP-2 that mediates cleavage of extracellular matrix components and plays pivotal roles in tumor migration, invasion and metastasis. Because in vivo noninvasive imaging of MT1-MMP would be useful for tumor diagnosis, we developed a novel near-infrared (NIR) fluorescence probe that can be activated following interaction with MT1-MMP in vivo. MT1-hIC7L is an activatable fluorescence probe comprised of anti-MT1-MMP monoclonal antibodies conjugated to self-assembling polymer micelles that encapsulate NIR dyes (IC7-1, λem : 858 nm) at concentrations sufficient to cause fluorescence self-quenching. In aqueous buffer, MT1-hIC7L fluorescence was suppressed to background levels and increased approximately 35.5-fold in the presence of detergent. Cellular uptake experiments revealed that in MT1-MMP positive C6 glioma cells, MT1-hIC7L showed significantly higher fluorescence that increased with time as compared to hIC7L, a negative control probe lacking the anti-MT1-MMP monoclonal antibody. In MT1-MMP negative MCF-7 breast adenocarcinoma cells, both MT1-hIC7L and hIC7L showed no obvious fluorescence. In addition, the fluorescence intensity of C6 cells treated with MT1-hIC7L was suppressed by pre-treatment with an MT1-MMP endocytosis inhibitor (P imaging using probes intravenously administered to tumor-bearing mice showed that MT1-hIC7L specifically visualized C6 tumors (tumor-to-background ratios: 3.8 ± 0.3 [MT1-hIC7L] vs 3.1 ± 0.2 [hIC7L] 48 h after administration, P fluorescence in MCF-7 tumors. Together, these results show that MT1-hIC7L would be a potential activatable NIR probe for specifically detecting MT1-MMP-expressing tumors. © 2014 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.

  3. On the temperature independence of statistical model parameters for cleavage fracture in ferritic steels

    Science.gov (United States)

    Qian, Guian; Lei, Wei-Sheng; Niffenegger, M.; González-Albuixech, V. F.

    2018-04-01

    The work relates to the effect of temperature on the model parameters in local approaches (LAs) to cleavage fracture. According to a recently developed LA model, the physical consensus of plastic deformation being a prerequisite to cleavage fracture enforces any LA model of cleavage fracture to observe initial yielding of a volume element as its threshold stress state to incur cleavage fracture in addition to the conventional practice of confining the fracture process zone within the plastic deformation zone. The physical consistency of the new LA model to the basic LA methodology and the differences between the new LA model and other existing models are interpreted. Then this new LA model is adopted to investigate the temperature dependence of LA model parameters using circumferentially notched round tensile specimens. With the published strength data as input, finite element (FE) calculation is conducted for elastic-perfectly plastic deformation and the realistic elastic-plastic hardening, respectively, to provide stress distributions for model calibration. The calibration results in temperature independent model parameters. This leads to the establishment of a 'master curve' characteristic to synchronise the correlation between the nominal strength and the corresponding cleavage fracture probability at different temperatures. This 'master curve' behaviour is verified by strength data from three different steels, providing a new path to calculate cleavage fracture probability with significantly reduced FE efforts.

  4. Expression of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-2 in radiation exposed small intestinal mucosa of the rat

    International Nuclear Information System (INIS)

    Kwag, Hyon Joo; Lee, Kyoung Ja; Rhee, Chung Sik

    2003-01-01

    The matrix metalloproteinases (MMPs) are a family of enzymes whose main function is the degradation of the extracellular matrix. Several studies have revealed that MMPs and TIMPs are related to the wound healing process and in photoaging caused by ultraviolet irradiation. However, the expressions of MMP and TIMP after irradiation have not, to the best of our knowledge, been studied. This study investigates the expressions of MMP-2 and TIMP-2 in rat intestinal mucosa following irradiation. The entire abdomen of Sprague-Dawley rats was irradiated using a single dose method. The rats were sacrificed on day 1, 2, 3, 5, 7 and 14 following irradiation. Histopathological observations were made using hematoxilin and eosin staining. The expressions of MMP-2 and TIMP-2 were examined using immunohistochemistry, immunoblotting and ELISA. Radiation induced damage, associated with atrophic villi, and infiltration of inflammatory cells was observed from the first postirradiation day, and severe tissue damage was observed on the second and the third postirradiation days. An increase in mitosis and the number of regenerating crypts, as evidence of regeneration, were most noticeable on the fifth postirradiation day. From the immunohistochemistry, the MMP-2 expression was observed from the first postirradiation day, but was most conspicuous on the third and the fifth postirradiation days. The TIMP-2 expression was most conspicuous on the fifth postirradiation day. From the immunoblotting, the MMP-2 expression was strongly positive on the third postirradiation day, and that of TIMP-2 showed a strong positive response on the fifth postirradiation day. In ELISA, tests, the expressions of MMP-2 and TIMP-2. were increased in the postirradiation groups compared to those of the normal controls, and showed a maximum increase on the fifth postirradiation day. These results were statistically significant. The expressions of MMP-2 and TIMP-2 were increased in the intestinal mucosa of the rats

  5. Social economy partnerships and the public/private cleavages

    Directory of Open Access Journals (Sweden)

    Joxerramon Bengoetxea

    2012-06-01

    Full Text Available Public/Private Partnerships can be seen as one particular topos where the divide between the public domain, all levels of the Public Administration and the private initiative and private property is turned into a joint venture rather than a confrontation or a cleavage. Some of the possible combinations of public and private and where public/private partnerships might fit are displayed analytically. The importance of political theory or ideology in conceiving the relationships between ‘public’ and ‘private’, and the conceptions of a market economy as opposed to a social market economy cannot be exaggerated enough, but equally important are the legal or regulatory framework and the underlying dominant legal culture and legal principles, and of course the economic and financial situation. Public/private partnerships thrive in some conditions, but seem to wane in others, and the current predicament is not favourable, taking into account that only the regulatory framework is supportive of these ventures. Los partenariados público-privados se pueden entender como un espacio particular, en el que el sector público, todos los niveles de la administración pública, y la iniciativa privada y la propiedad privada, abordan una empresa conjunta, en lugar mantener posturas contrapuestas. Se muestran algunas de las posibles combinaciones del sector público y privado, en las que tendrían cabida los partenariados público/privados. Es patente la importancia de la teoría o la ideología política para entender las relaciones entre lo público y lo privado, y las concepciones de una economía de mercado frente a una economía social, pero tampoco se puede negar la importancia del marco legal o reglamentario y la cultura jurídica dominante subyacente, y los principios jurídicos, sin olvidar la situación económica y financiera. Los partenariados público-privados prosperan en algunas condiciones, pero no lo hacen siempre, y la situación econ

  6. Matrix metalloproteinase-2 is a consistent prognostic factor in gastric cancer.

    NARCIS (Netherlands)

    Kubben, F.J.G.M.; Sier, C.F.M.; Duijn, W. van; Griffioen, G.; Hanemaaijer, R.; Velde, C.J. van de; Krieken, J.H.J.M. van; Lamers, C.B.H.W.; Verspaget, H.W.

    2006-01-01

    In a pioneer study, we showed 10 years ago that enhanced tissue levels of the matrix metalloproteinases (MMPs) MMP-2 and MMP-9 in gastric cancers, as determined by zymography, were related with worse overall survival of the patients. To corroborate these observations, we now assessed MMP-2 and MMP-9

  7. Exercise Prevents Diaphragm Wasting Induced by Cigarette Smoke through Modulation of Antioxidant Genes and Metalloproteinases

    Directory of Open Access Journals (Sweden)

    Gracielle Vieira Ramos

    2018-01-01

    Full Text Available Background. The present study aimed to analyze the effects of physical training on an antioxidant canonical pathway and metalloproteinases activity in diaphragm muscle in a model of cigarette smoke-induced chronic obstructive pulmonary disease (COPD. Methods. Male mice were randomized into control, smoke, exercise, and exercise + smoke groups, which were maintained in trial period of 24 weeks. Gene expression of kelch-like ECH-associated protein 1; nuclear factor erythroid-2 like 2; and heme-oxygenase1 by polymerase chain reaction was performed. Metalloproteinases 2 and 9 activities were analyzed by zymography. Exercise capacity was evaluated by treadmill exercise test before and after the protocol. Results. Aerobic training inhibited diaphragm muscle wasting induced by cigarette smoke exposure. This inhibition was associated with improved aerobic capacity in those animals that were submitted to 24 weeks of aerobic training, when compared to the control and smoke groups, which were not submitted to training. The aerobic training also downregulated the increase of matrix metalloproteinases (MMP-2 and MMP-9 and upregulated antioxidant genes, such as nuclear factor erythroid-2 like 2 (NRF2 and heme-oxygenase1 (HMOX1, in exercise + smoke group compared to smoke group. Conclusions. Treadmill aerobic training protects diaphragm muscle wasting induced by cigarette smoke exposure involving upregulation of antioxidant genes and downregulation of matrix metalloproteinases.

  8. Increased matrix metalloproteinase-8 and -9 activity in patients with infarct rupture after myocardial infarction

    NARCIS (Netherlands)

    Borne, S.W.M. van den; Cleutjens, J.P.M.; Hanemaaijer, R.; Creemers, E.E.; Smits, J.F.M.; Daemen, M.J.A.P.; Blankesteijn, W.M.

    2009-01-01

    Background: Infarct rupture is a usually fatal complication of myocardial infarction (MI), for which no molecular mechanism has been described in humans. Experimental evidence in mouse models suggests that the degradation of the extracellular matrix by matrix metalloproteinases (MMPs) plays an

  9. Structures and Functions of Snake Venom Metalloproteinases (SVMP) from Protobothrops venom Collected in Japan.

    Science.gov (United States)

    Oyama, Etsuko; Takahashi, Hidenobu

    2017-08-04

    Snake venom metalloproteinases (SVMP) are widely distributed among the venoms of Crotalinae and Viperidae, and are organized into three classes (P-I, P-II and P-III) according to their size and domain structure. P-I SVMP are the smallest SVMP, as they only have a metalloproteinase (M) domain. P-II SVMP contain a disintegrin-like (D) domain, which is connected by a short spacer region to the carboxyl terminus of the M domain. P-III SVMP contain a cysteine-rich (C) domain, which is attached to the carboxyl terminus of the D domain. Some SVMP exhibit hemorrhagic activity, whereas others do not. In addition, SVMP display fibrinolytic/fibrinogenolytic (FL) activity, and the physiological functions of SVMP are controlled by their structures. Furthermore, these proteinases also demonstrate fibrinogenolytic and proteolytic activity against synthetic substrates for matrix metalloproteinases and ADAM (a disintegrin and metalloproteinase). This article describes the structures and FL, hemorrhagic, and platelet aggregation-inhibiting activity of SVMP derived from Protobothrops snake venom that was collected in Japan.

  10. Matrix metalloproteinase-2 is a consistent prognostic factor in gastric cancer

    NARCIS (Netherlands)

    Kubben, F.J.G.M.; Sier, C.F.M.; Duijn, W. van; Griffioen, G.; Hanemaaijer, R.; Velde, C.J.H. van de; Krieken, J.H.J.M. van; Lamers, C.B.H.W.; Verspaget, H.W.

    2006-01-01

    In a pioneer study, we showed 10 years ago that enhanced tissue levels of the matrix metalloproteinases (MMPs) MMP-2 and MMP-9 in gastric cancers, as determined by zymography, were related with worse overall survival of the patients. To corroborate these observations, we now assessed MMP-2 and MMP-9

  11. Suramin Inhibits Osteoarthritic Cartilage Degradation by Increasing Extracellular Levels of Chondroprotective Tissue Inhibitor of Metalloproteinases 3.

    Science.gov (United States)

    Chanalaris, Anastasios; Doherty, Christine; Marsden, Brian D; Bambridge, Gabriel; Wren, Stephen P; Nagase, Hideaki; Troeberg, Linda

    2017-10-01

    Osteoarthritis is a common degenerative joint disease for which no disease-modifying drugs are currently available. Attempts to treat the disease with small molecule inhibitors of the metalloproteinases that degrade the cartilage matrix have been hampered by a lack of specificity. We aimed to inhibit cartilage degradation by augmenting levels of the endogenous metalloproteinase inhibitor, tissue inhibitor of metalloproteinases (TIMP)-3, through blocking its interaction with the endocytic scavenger receptor, low-density lipoprotein receptor-related protein 1 (LRP1). We discovered that suramin (C 51 H 40 N 6 O 23 S 6 ) bound to TIMP-3 with a K D value of 1.9 ± 0.2 nM and inhibited its endocytosis via LRP1, thus increasing extracellular levels of TIMP-3 and inhibiting cartilage degradation by the TIMP-3 target enzyme, adamalysin-like metalloproteinase with thrombospondin motifs 5. NF279 (8,8'-[carbonyl bis (imino-4,1-phenylenecarbonylimino-4,1-phenylenecarbonylimino)] bis -1,3,5-naphthalenetrisulfonic acid hexasodium salt), a structural analog of suramin, has an increased affinity for TIMP-3 and increased ability to inhibit TIMP-3 endocytosis and protect cartilage. Suramin is thus a promising scaffold for the development of novel therapeutics to increase TIMP-3 levels and inhibit cartilage degradation in osteoarthritis. Copyright © 2017 by The Author(s).

  12. Early increased levels of matrix metalloproteinase-9 in neonates recovering from respiratory distress syndrome

    NARCIS (Netherlands)

    Dik, Willem A.; van Kaam, Anton H. L. C.; Dekker, Tamara; Naber, Brigitta A. E.; Janssen, Daphne J.; Kroon, A. A.; Zimmermann, Luc J. I.; Versnel, Marjan A.; Lutter, René

    2006-01-01

    Aim: Matrix metalloproteinases (MMPs) play an eminent role in airway injury and remodelling. We explored the hypothesis that pulmonary MMP levels would differ early after birth (2-4 days) between infants with resolving respiratory distress syndrome (RDS) and infants developing chronic lung disease

  13. Tissue inhibitor of metalloproteinase 1 (TIMP-1) as a biomarker in gastric cancer

    DEFF Research Database (Denmark)

    Grunnet, Mie; Mau-Sørensen, Morten; Brünner, Nils

    2013-01-01

    The value of Tissue Inhibitor of MetalloProteinase-1 (TIMP-1) as a biomarker in patients with gastric cancer (GC) is widely debated. The aim of this review is to evaluate available literature describing the association between levels of TIMP-1 in tumor tissue and/or blood and the prognosis...

  14. Evaluation of an improved tissue inhibitor of metalloproteinase 1 dual monoclonal sandwich immunoassay

    DEFF Research Database (Denmark)

    Sørensen, Nanna Møller; Blincko, Stuart; Dinsmore, Emma

    2006-01-01

    BACKGROUND: It has previously been shown that increased levels of plasma tissue inhibitor of metalloproteinase 1 (TIMP-1) is associated with shorter survival for patients with colorectal cancer (CRC). Furthermore, plasma TIMP-1 levels have been found to be elevated in patients with early-stage CR...

  15. IgE-mediated basophil tumour necrosis factor alpha induces matrix metalloproteinase-9 from monocytes

    DEFF Research Database (Denmark)

    Falkencrone, Sidsel; Poulsen, Lars K.; Bindslev-Jensen, Carsten

    2013-01-01

    IgE-mediated activation of mast cells has been reported to induce the release of tumour necrosis alpha (TNF-α), which may display autocrine effects on these cells by inducing the generation of the tissue remodelling protease matrix metalloproteinase-9 (MMP-9). While mast cells and basophils have...

  16. Downregulation of membrane type-matrix metalloproteinases in the inflamed or injured central nervous system

    DEFF Research Database (Denmark)

    Toft-Hansen, Henrik; Babcock, Alicia A; Millward, Jason M

    2007-01-01

    BACKGROUND: Matrix metalloproteinases (MMPs) are thought to mediate cellular infiltration in central nervous system (CNS) inflammation by cleaving extracellular matrix proteins associated with the blood-brain barrier. The family of MMPs includes 23 proteinases, including six membrane type-MMPs (M...

  17. The potato carotenoid cleavage dioxygenase 4 catalyzes a single cleavage of β-ionone ring-containing carotenes and non-epoxidated xanthophylls

    KAUST Repository

    Bruno, Mark; Beyer, Peter D.; Al-Babili, Salim

    2015-01-01

    amounts. This phenotype indicates a role of this enzyme in tuber development, which may be exerted by a cleavage product. In this work, we investigated the enzymatic activity of StCCD4, by expressing the corresponding cDNA in carotenoid accumulating

  18. Quantitative characterization of cleavage and hydrogen-assisted quasi-cleavage fracture surfaces with the use of confocal laser scanning microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Merson, E. [Institute of Advanced Technologies, Togliatti State University, 445667 (Russian Federation); Kudrya, A.V.; Trachenko, V.A. [Department of Physical Metallurgy and the Physics of Strength, NUST MISiS, Moscow 119490 (Russian Federation); Merson, D. [Institute of Advanced Technologies, Togliatti State University, 445667 (Russian Federation); Laboratory for Advanced Materials, Kazan Federal University, Naberezhnye Chelny 423812, Republic of Tatarstan (Russian Federation); Danilov, V. [Institute of Advanced Technologies, Togliatti State University, 445667 (Russian Federation); Vinogradov, A. [Institute of Advanced Technologies, Togliatti State University, 445667 (Russian Federation); Department of Engineering Design and Materials, Norwegian University of Science and Technology – NTNU, N-7491 Trondheim (Norway)

    2016-05-17

    “True” cleavage (TC) and quasi-cleavage (QC) fracture surfaces of low-carbon steel specimens tested in liquid nitrogen and after hydrogen charging respectively were investigated by quantitative confocal laser scanning microscopy (CLSM) and conventional scanning electron microscopy (SEM) with electron-backscattered diffraction (EBSD). Topological and crystallographic features of the TC fracture surface are found in good agreement with the generally accepted cleavage mechanism: TC facets diameters correspond to those of grains; the crack path strictly follows the crystallographic orientation of grains and the most of the cleavage cracks are parallel to {100} planes. On the 2D SEM images, the QC facets appeared resembling the TC ones in terms of river line patterns, shapes and sizes. However, the substantial differences between the topography of these two kinds of fracture surfaces were revealed by 3D CLSM: the average misorientation angle between QC facets and the roughness of the QC fracture surface were much lower than those measured for TC. It is demonstrated that all these features are attributed to the specific fracture mechanism operating during hydrogen-assisted cracking.

  19. Quantitative characterization of cleavage and hydrogen-assisted quasi-cleavage fracture surfaces with the use of confocal laser scanning microscopy

    International Nuclear Information System (INIS)

    Merson, E.; Kudrya, A.V.; Trachenko, V.A.; Merson, D.; Danilov, V.; Vinogradov, A.

    2016-01-01

    “True” cleavage (TC) and quasi-cleavage (QC) fracture surfaces of low-carbon steel specimens tested in liquid nitrogen and after hydrogen charging respectively were investigated by quantitative confocal laser scanning microscopy (CLSM) and conventional scanning electron microscopy (SEM) with electron-backscattered diffraction (EBSD). Topological and crystallographic features of the TC fracture surface are found in good agreement with the generally accepted cleavage mechanism: TC facets diameters correspond to those of grains; the crack path strictly follows the crystallographic orientation of grains and the most of the cleavage cracks are parallel to {100} planes. On the 2D SEM images, the QC facets appeared resembling the TC ones in terms of river line patterns, shapes and sizes. However, the substantial differences between the topography of these two kinds of fracture surfaces were revealed by 3D CLSM: the average misorientation angle between QC facets and the roughness of the QC fracture surface were much lower than those measured for TC. It is demonstrated that all these features are attributed to the specific fracture mechanism operating during hydrogen-assisted cracking.

  20. Tomato carotenoid cleavage dioxygenases 1A and 1B: Relaxed double bond specificity leads to a plenitude of dialdehydes, mono-apocarotenoids and isoprenoid volatiles

    KAUST Repository

    Ilg, Andrea; Bruno, Mark; Beyer, Peter; Al-Babili, Salim

    2014-01-01

    The biosynthetic processes leading to many of the isoprenoid volatiles released by tomato fruits are still unknown, though previous reports suggested a clear correlation with the carotenoids contained within the fruit. In this study, we investigated the activity of the tomato (Solanum lycopersicum) carotenoid cleavage dioxygenase (SlCCD1B), which is highly expressed in fruits, and of its homolog SlCCD1A. Using in vitro assays performed with purified recombinant enzymes and by analyzing products formed by the two enzymes in carotene-accumulating Escherichia coli strains, we demonstrate that SlCCD1A and, to a larger extent, SlCCD1B, have a very relaxed specificity for both substrate and cleavage site, mediating the oxidative cleavage of cis- and all-. trans-carotenoids as well as of different apocarotenoids at many more double bonds than previously reported. This activity gives rise to a plenitude of volatiles, mono-apocarotenoids and dialdehyde products, including cis-pseudoionone, neral, geranial, and farnesylacetone. Our results provide a direct evidence for a carotenoid origin of these compounds and point to CCD1s as the enzymes catalyzing the formation of the vast majority of tomato isoprenoid volatiles, many of which are aroma constituents. © 2014 The Authors.

  1. Tomato carotenoid cleavage dioxygenases 1A and 1B: Relaxed double bond specificity leads to a plenitude of dialdehydes, mono-apocarotenoids and isoprenoid volatiles

    KAUST Repository

    Ilg, Andrea

    2014-06-25

    The biosynthetic processes leading to many of the isoprenoid volatiles released by tomato fruits are still unknown, though previous reports suggested a clear correlation with the carotenoids contained within the fruit. In this study, we investigated the activity of the tomato (Solanum lycopersicum) carotenoid cleavage dioxygenase (SlCCD1B), which is highly expressed in fruits, and of its homolog SlCCD1A. Using in vitro assays performed with purified recombinant enzymes and by analyzing products formed by the two enzymes in carotene-accumulating Escherichia coli strains, we demonstrate that SlCCD1A and, to a larger extent, SlCCD1B, have a very relaxed specificity for both substrate and cleavage site, mediating the oxidative cleavage of cis- and all-. trans-carotenoids as well as of different apocarotenoids at many more double bonds than previously reported. This activity gives rise to a plenitude of volatiles, mono-apocarotenoids and dialdehyde products, including cis-pseudoionone, neral, geranial, and farnesylacetone. Our results provide a direct evidence for a carotenoid origin of these compounds and point to CCD1s as the enzymes catalyzing the formation of the vast majority of tomato isoprenoid volatiles, many of which are aroma constituents. © 2014 The Authors.

  2. Tomato carotenoid cleavage dioxygenases 1A and 1B: Relaxed double bond specificity leads to a plenitude of dialdehydes, mono-apocarotenoids and isoprenoid volatiles

    Directory of Open Access Journals (Sweden)

    Andrea Ilg

    2014-01-01

    Full Text Available The biosynthetic processes leading to many of the isoprenoid volatiles released by tomato fruits are still unknown, though previous reports suggested a clear correlation with the carotenoids contained within the fruit. In this study, we investigated the activity of the tomato (Solanum lycopersicum carotenoid cleavage dioxygenase (SlCCD1B, which is highly expressed in fruits, and of its homolog SlCCD1A. Using in vitro assays performed with purified recombinant enzymes and by analyzing products formed by the two enzymes in carotene-accumulating Escherichia coli strains, we demonstrate that SlCCD1A and, to a larger extent, SlCCD1B, have a very relaxed specificity for both substrate and cleavage site, mediating the oxidative cleavage of cis- and all-trans-carotenoids as well as of different apocarotenoids at many more double bonds than previously reported. This activity gives rise to a plenitude of volatiles, mono-apocarotenoids and dialdehyde products, including cis-pseudoionone, neral, geranial, and farnesylacetone. Our results provide a direct evidence for a carotenoid origin of these compounds and point to CCD1s as the enzymes catalyzing the formation of the vast majority of tomato isoprenoid volatiles, many of which are aroma constituents.

  3. CRISPR/Cas9 cleavages in budding yeast reveal templated insertions and strand-specific insertion/deletion profiles.

    Science.gov (United States)

    Lemos, Brenda R; Kaplan, Adam C; Bae, Ji Eun; Ferrazzoli, Alexander E; Kuo, James; Anand, Ranjith P; Waterman, David P; Haber, James E

    2018-02-27

    Harnessing CRISPR-Cas9 technology provides an unprecedented ability to modify genomic loci via DNA double-strand break (DSB) induction and repair. We analyzed nonhomologous end-joining (NHEJ) repair induced by Cas9 in budding yeast and found that the orientation of binding of Cas9 and its guide RNA (gRNA) profoundly influences the pattern of insertion/deletions (indels) at the site of cleavage. A common indel created by Cas9 is a 1-bp (+1) insertion that appears to result from Cas9 creating a 1-nt 5' overhang that is filled in by a DNA polymerase and ligated. The origin of +1 insertions was investigated by using two gRNAs with PAM sequences located on opposite DNA strands but designed to cleave the same sequence. These templated +1 insertions are dependent on the X-family DNA polymerase, Pol4. Deleting Pol4 also eliminated +2 and +3 insertions, which are biased toward homonucleotide insertions. Using inverted PAM sequences, we also found significant differences in overall NHEJ efficiency and repair profiles, suggesting that the binding of the Cas9:gRNA complex influences subsequent NHEJ processing. As with events induced by the site-specific HO endonuclease, CRISPR-Cas9-mediated NHEJ repair depends on the Ku heterodimer and DNA ligase 4. Cas9 events are highly dependent on the Mre11-Rad50-Xrs2 complex, independent of Mre11's nuclease activity. Inspection of the outcomes of a large number of Cas9 cleavage events in mammalian cells reveals a similar templated origin of +1 insertions in human cells, but also a significant frequency of similarly templated +2 insertions.

  4. DNA binding and cleavage studies of new sulfasalazine-derived dipeptide Zn(II) complex: Validation for specific recognition with 5 Prime -TMP

    Energy Technology Data Exchange (ETDEWEB)

    Tabassum, Sartaj [Department of Chemistry, Aligarh Muslim University, Aligarh, UP 202002 (India); Al-Asbahy, Waddhaah M.; Afzal, Mohd.; Shamsi, Manal; Arjmand, Farukh [Department of Chemistry, Aligarh Muslim University, Aligarh, UP 202002 (India)

    2012-11-15

    A new water soluble complex [Zn(glygly)(ssz)(H{sub 2}O)]{center_dot}6H{sub 2}O, 1 derived from dipeptide (glycyl glycine) and sulfasalazine was synthesized and characterized by spectroscopic (IR, UV-vis, NMR, ESI-MS) and analytical methods. The in vitro DNA binding studies of complex 1 with calf-thymus DNA were carried out by employing various biophysical methods and molecular docking technique which reveals strong electrostatic binding via phosphate backbone of DNA helix, in addition to partial intercalation. To gain further insight into the molecular recognition at the target site, interaction studies of complex 1 with 5 Prime -TMP and 5 Prime -GMP were carried out by UV-vis titration which was validated by {sup 1}H and {sup 31}P NMR with 5 Prime -TMP, which implicate the preferential selectivity of 1 towards N3 of thymine. Complex 1 is accessible to minor groove of DNA and cleaved pBR322 DNA via hydrolytic pathway (validated by T4 ligase assay). - Graphical abstract: Synthesis, characterization, DNA binding and cleavage studies of [Zn(glygly)(ssz)(H{sub 2}O)]{center_dot}6H{sub 2}O (1) containing glycyl glycine and sulfasalazine ligand. Complex 1 recognize minor groove of DNA and show hydrolytic DNA cleavage. Highlights: Black-Right-Pointing-Pointer Novel Zn(II) complex 1 bearing bioactive glycyl glycine and sulfasalazine ligand scaffold. Black-Right-Pointing-Pointer Cleavage activity of 1 was enhanced in presence of activators: H{sub 2}O{sub 2}>MPA>GSH>Asc. Black-Right-Pointing-Pointer Complex 1 recognize minor groove as depicted in the cleavage pattern and molecular docking. Black-Right-Pointing-Pointer Complex 1 cleaves pBR322 DNA via hydrolytic mechanism and validated by T4 DNA ligase experiments.

  5. DNA binding and cleavage studies of new sulfasalazine-derived dipeptide Zn(II) complex: Validation for specific recognition with 5′–TMP

    International Nuclear Information System (INIS)

    Tabassum, Sartaj; Al–Asbahy, Waddhaah M.; Afzal, Mohd.; Shamsi, Manal; Arjmand, Farukh

    2012-01-01

    A new water soluble complex [Zn(glygly)(ssz)(H 2 O)]·6H 2 O, 1 derived from dipeptide (glycyl glycine) and sulfasalazine was synthesized and characterized by spectroscopic (IR, UV–vis, NMR, ESI–MS) and analytical methods. The in vitro DNA binding studies of complex 1 with calf–thymus DNA were carried out by employing various biophysical methods and molecular docking technique which reveals strong electrostatic binding via phosphate backbone of DNA helix, in addition to partial intercalation. To gain further insight into the molecular recognition at the target site, interaction studies of complex 1 with 5′-TMP and 5′-GMP were carried out by UV–vis titration which was validated by 1 H and 31 P NMR with 5′-TMP, which implicate the preferential selectivity of 1 towards N3 of thymine. Complex 1 is accessible to minor groove of DNA and cleaved pBR322 DNA via hydrolytic pathway (validated by T4 ligase assay). - Graphical abstract: Synthesis, characterization, DNA binding and cleavage studies of [Zn(glygly)(ssz)(H 2 O)]·6H 2 O (1) containing glycyl glycine and sulfasalazine ligand. Complex 1 recognize minor groove of DNA and show hydrolytic DNA cleavage. Highlights: ► Novel Zn(II) complex 1 bearing bioactive glycyl glycine and sulfasalazine ligand scaffold. ► Cleavage activity of 1 was enhanced in presence of activators: H 2 O 2 >MPA>GSH>Asc. ► Complex 1 recognize minor groove as depicted in the cleavage pattern and molecular docking. ► Complex 1 cleaves pBR322 DNA via hydrolytic mechanism and validated by T4 DNA ligase experiments.

  6. Translation of Polioviral mRNA Is Inhibited by Cleavage of Polypyrimidine Tract-Binding Proteins Executed by Polioviral 3Cpro

    Science.gov (United States)

    Back, Sung Hoon; Kim, Yoon Ki; Kim, Woo Jae; Cho, Sungchan; Oh, Hoe Rang; Kim, Jung-Eun; Jang, Sung Key

    2002-01-01

    The translation of polioviral mRNA occurs through an internal ribosomal entry site (IRES). Several RNA-binding proteins, such as polypyrimidine tract-binding protein (PTB) and poly(rC)-binding protein (PCBP), are required for the poliovirus IRES-dependent translation. Here we report that a poliovirus protein, 3Cpro (and/or 3CDpro), cleaves PTB isoforms (PTB1, PTB2, and PTB4). Three 3Cpro target sites (one major target site and two minor target sites) exist in PTBs. PTB fragments generated by poliovirus infection are redistributed to the cytoplasm from the nucleus, where most of the intact PTBs are localized. Moreover, these PTB fragments inhibit polioviral IRES-dependent translation in a cell-based assay system. We speculate that the proteolytic cleavage of PTBs may contribute to the molecular switching from translation to replication of polioviral RNA. PMID:11836431

  7. Kininogen Cleavage Assay: Diagnostic Assistance for Kinin-Mediated Angioedema Conditions.

    Directory of Open Access Journals (Sweden)

    Rémi Baroso

    Full Text Available Angioedema without wheals (AE is a symptom characterised by localised episodes of oedema presumably caused by kinin release from kininogen cleavage. It can result from a hereditary deficiency in C1 Inhibitor (C1Inh, but it can present with normal level of C1Inh. These forms are typically difficult to diagnose although enhanced kinin production is suspected or demonstrated in some cases.We wanted to investigate bradykinin overproduction in all AE condition with normal C1Inh, excluding cases with enhanced kinin catabolism, and to propose this parameter as a disease biomarker.We retrospectively investigated high molecular weight kininogen (HK cleavage pattern, using gel electrophoresis and immunorevelation. Plasma samples were drawn using the same standardised procedure from blood donors or AE patients with normal C1Inh conditions, normal kinin catabolism, and without prophylaxis.Circulating native HK plasma concentrations were similar in the healthy men (interquartile range: 98-175μg/mL, n = 51 and in healthy women (90-176μg/mL, n = 74, while HK cleavage was lower (p14.4% HK cleavage for men; 33.0% HK cleavage for women, with >98% specificity achieved for all parameters. In plasma from patients undergoing recovery two months after oestrogen/progestin combination withdrawal (n = 13 or two weeks after AE attack (n = 2, HK cleavage was not fully restored, suggesting its use as a post-attack assay.As a diagnostic tool, HK cleavage can offer physicians supportive arguments for kinin production in suspected AE cases and improve patient follow-up in clinical trials or prophylactic management.

  8. Initiation of cleavage in a low alloy steel: effect of a ductile damage localized around inclusions; Declenchement du clivage dans un acier faiblement allie: role de l'endommagement ductile localise autour des inclusions

    Energy Technology Data Exchange (ETDEWEB)

    Carassou, S

    2000-07-01

    The fracture mechanism in a low alloy steel, used in the pressurised water reactor vessel, has been studied in the ductile to brittle transition temperature range. We used the local approach of fracture in conjunction with both fractographic observations and numerical simulations. Previous studies suggested the onset of cleavage to be favoured by the presence of nearby manganese sulphide (MnS) clusters: the ductile damaged zone localised inside a cluster increases the stress around it, and so contribute to the triggering of cleavage due to nearby classical sites, like carbides. The experimental study of size dependence and anisotropy on the global fracture behaviour, together with fractographic observations, give here the proof of the influence of MnS clusters on the onset of cleavage in this steel. Fracture behaviour of pre-cracked specimens tested in the transition regime has then been simulated, by three dimensional finite element method computations. Ductile tearing process preceding the cleavage onset at those temperatures regime was well reproduced by the Rousselier's model. Failure probabilities, related to given stress states, has been given by post-processor calculations, using a probabilistic model based on the specific cleavage fracture process. Fracture toughness scatter of the steel, tested in the transition regime, is then well reproduced by those calculations. However, the critical cleavage stress of an elementary volume, that scales for the fracture process, is still assumed to be temperature dependant. Numerical simulations of the local fracture process suggest that this temperature effect can partly be explained by the temperature dependant decrease of the stress amplification due to the MnS clusters. (author)

  9. Beta-scission of alkoxyl radicals on peptides and proteins can give rise to backbone cleavage and loss of side-chains

    International Nuclear Information System (INIS)

    Headlam, H.A.; Davies, M.J.; Mortimer, A.; Easton, C.J.

    2000-01-01

    Full text: Exposure of proteins to radicals in the presence of O 2 brings about multiple changes including side-chain oxidation, backbone fragmentation, cross-linking, unfolding, changes in hydrophobicity and conformation, altered susceptibility to proteolytic enzymes and formation of new reactive groups (e.g. hydroperoxides and 3,4-dihydroxyphenylalanine). All of these processes can result in loss of structural or enzymatic activity. The mechanisms that give rise to backbone cleavage are only partly understood. Whilst it is known that direct hydrogen atom abstraction at a-carbon sites gives backbone cleavages it has also been proposed that initial attack at side-chain sites might also give rise to backbone cleavage. In this study we have examined whether initial attack at the β- (C-3) position can give rise to α-carbon radicals (and hence backbone cleavage) via the formation, and subsequent β- scission, of C-3 alkoxyl radicals. This process has been observed previously with protected amino acids in organic solvents (J. Chem. Soc. Perkin Trans. 2, 1997, 503-507) but the occurrence of such reactions with proteins in aqueous solution has not been explored. Alkoxyl radicals were generated at the C-3 position of a variety of protected amino acids and small peptides by two methods: metal-ion catalysed decomposition of hydroperoxides formed as a result of γ-radiolysis in the presence of O 2 , and UV photolysis of nitrate esters. In most cases radicals have been detected by EPR spectroscopy using nitroso and nitrone spin traps, which can be assigned by comparison with literature data to α-carbon radicals; in some case assignments were confirmed by the generation of the putative species by other routes. With Ala peptide hydroperoxides and nitrate esters, and MNP as the spin trap, the major radical detected in each case has been assigned to the adduct of an α-carbon radical with partial structure - NH- . CH-C(O) - consistent with the rapid occurrence of the above

  10. Two Distinct Isoforms of Matrix Metalloproteinase-2 Are Associated with Human Delayed Kidney Graft Function.

    Directory of Open Access Journals (Sweden)

    Shaynah Wanga

    Full Text Available Delayed graft function (DGF is a frequent complication of renal transplantation, particularly in the setting of transplantation of kidneys derived from deceased donors and expanded-criteria donors. DGF results from tubular epithelial cell injury and has immediate and long term consequences. These include requirement for post-transplantation dialysis, increased incidence of acute rejection, and poorer long-term outcomes. DGF represents one of the clearest clinical examples of renal acute ischemia/reperfusion injury. Experimental studies have demonstrated that ischemia/reperfusion injury induces the synthesis of the full length secreted isoform of matrix metalloproteinase-2 (FL-MMP-2, as well as an intracellular N-terminal truncated MMP-2 isoform (NTT-MMP-2 that initiates an innate immune response. We hypothesized that the two MMP-2 isoforms mediate tubular epithelial cell injury in DGF. Archival renal biopsy sections from 10 protocol biopsy controls and 41 cases with a clinical diagnosis of DGF were analyzed for the extent of tubular injury, expression of the FL-MMP-2 and NTT-MMP-2 isoforms by immunohistochemistry (IHC, in situ hybridization, and qPCR to determine isoform abundance. Differences in transcript abundance were related to tubular injury score. Markers of MMP-2-mediated injury included TUNEL staining and assessment of peritubular capillary density. There was a clear relationship between tubular epithelial cell expression of both FL-MMP-2 and NTT-MMP-2 IHC with the extent of tubular injury. The MMP-2 isoforms were detected in the same tubular segments and were present at sites of tubular injury. qPCR demonstrated highly significant increases in both the FL-MMP-2 and NTT-MMP-2 transcripts. Statistical analysis revealed highly significant associations between FL-MMP-2 and NTT-MMP-2 transcript abundance and the extent of tubular injury, with NTT-MMP-2 having the strongest association. We conclude that two distinct MMP-2 isoforms are

  11. Protein cleavage strategies for an improved analysis of the membrane proteome

    Directory of Open Access Journals (Sweden)

    Poetsch Ansgar

    2006-03-01

    Full Text Available Abstract Background Membrane proteins still remain elusive in proteomic studies. This is in part due to the distribution of the amino acids lysine and arginine, which are less frequent in integral membrane proteins and almost absent in transmembrane helices. As these amino acids are cleavage targets for the commonly used protease trypsin, alternative cleavage conditions, which should improve membrane protein analysis, were tested by in silico digestion for the three organisms Saccharomyces cerevisiae, Halobacterium sp. NRC-1, and Corynebacterium glutamicum as hallmarks for eukaryotes, archea and eubacteria. Results For the membrane proteomes from all three analyzed organisms, we identified cleavage conditions that achieve better sequence and proteome coverage than trypsin. Greater improvement was obtained for bacteria than for yeast, which was attributed to differences in protein size and GRAVY. It was demonstrated for bacteriorhodopsin that the in silico predictions agree well with the experimental observations. Conclusion For all three examined organisms, it was found that a combination of chymotrypsin and staphylococcal peptidase I gave significantly better results than trypsin. As some of the improved cleavage conditions are not more elaborate than trypsin digestion and have been proven useful in practice, we suppose that the cleavage at both hydrophilic and hydrophobic amino acids should facilitate in general the analysis of membrane proteins for all organisms.

  12. Caspase Cleavages of the Lymphocyte-oriented Kinase Prevent Ezrin, Radixin, and Moesin Phosphorylation during Apoptosis*

    Science.gov (United States)

    Leroy, Catherine; Belkina, Natalya V.; Long, Thavy; Deruy, Emeric; Dissous, Colette; Shaw, Stephen; Tulasne, David

    2016-01-01

    The lymphocyte-oriented kinase (LOK), also called serine threonine kinase 10 (STK10), is synthesized mainly in lymphocytes. It is involved in lymphocyte migration and polarization and can phosphorylate ezrin, radixin, and moesin (the ERM proteins). In a T lymphocyte cell line and in purified human lymphocytes, we found LOK to be cleaved by caspases during apoptosis. The first cleavage occurs at aspartic residue 332, located between the kinase domain and the coiled-coil regulation domain. This cleavage generates an N-terminal fragment, p50 N-LOK, containing the kinase domain and a C-terminal fragment, which is further cleaved during apoptosis. Although these cleavages preserve the entire kinase domain, p50 N-LOK displays no kinase activity. In apoptotic lymphocytes, caspase cleavages of LOK are concomitant with a decrease in ERM phosphorylation. When non-apoptotic lymphocytes from mice with homozygous and heterozygous LOK knockout were compared, the latter showed a higher level of ERM phosphorylation, but when apoptosis was induced, LOK−/− and LOK+/− lymphocytes showed the same low level, confirming in vivo that LOK-induced ERM phosphorylation is prevented during lymphocyte apoptosis. Our results demonstrate that cleavage of LOK during apoptosis abolishes its kinase activity, causing a decrease in ERM phosphorylation, crucial to the role of the ERM proteins in linking the plasma membrane to actin filaments. PMID:26945071

  13. Caspase Cleavages of the Lymphocyte-oriented Kinase Prevent Ezrin, Radixin, and Moesin Phosphorylation during Apoptosis.

    Science.gov (United States)

    Leroy, Catherine; Belkina, Natalya V; Long, Thavy; Deruy, Emeric; Dissous, Colette; Shaw, Stephen; Tulasne, David

    2016-05-06

    The lymphocyte-oriented kinase (LOK), also called serine threonine kinase 10 (STK10), is synthesized mainly in lymphocytes. It is involved in lymphocyte migration and polarization and can phosphorylate ezrin, radixin, and moesin (the ERM proteins). In a T lymphocyte cell line and in purified human lymphocytes, we found LOK to be cleaved by caspases during apoptosis. The first cleavage occurs at aspartic residue 332, located between the kinase domain and the coiled-coil regulation domain. This cleavage generates an N-terminal fragment, p50 N-LOK, containing the kinase domain and a C-terminal fragment, which is further cleaved during apoptosis. Although these cleavages preserve the entire kinase domain, p50 N-LOK displays no kinase activity. In apoptotic lymphocytes, caspase cleavages of LOK are concomitant with a decrease in ERM phosphorylation. When non-apoptotic lymphocytes from mice with homozygous and heterozygous LOK knockout were compared, the latter showed a higher level of ERM phosphorylation, but when apoptosis was induced, LOK(-/-) and LOK(+/-) lymphocytes showed the same low level, confirming in vivo that LOK-induced ERM phosphorylation is prevented during lymphocyte apoptosis. Our results demonstrate that cleavage of LOK during apoptosis abolishes its kinase activity, causing a decrease in ERM phosphorylation, crucial to the role of the ERM proteins in linking the plasma membrane to actin filaments. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  14. A machine learning approach for predicting CRISPR-Cas9 cleavage efficiencies and patterns underlying its mechanism of action.

    Science.gov (United States)

    Abadi, Shiran; Yan, Winston X; Amar, David; Mayrose, Itay

    2017-10-01

    The adaptation of the CRISPR-Cas9 system as a genome editing technique has generated much excitement in recent years owing to its ability to manipulate targeted genes and genomic regions that are complementary to a programmed single guide RNA (sgRNA). However, the efficacy of a specific sgRNA is not uniquely defined by exact sequence homology to the target site, thus unintended off-targets might additionally be cleaved. Current methods for sgRNA design are mainly concerned with predicting off-targets for a given sgRNA using basic sequence features and employ elementary rules for ranking possible sgRNAs. Here, we introduce CRISTA (CRISPR Target Assessment), a novel algorithm within the machine learning framework that determines the propensity of a genomic site to be cleaved by a given sgRNA. We show that the predictions made with CRISTA are more accurate than other available methodologies. We further demonstrate that the occurrence of bulges is not a rare phenomenon and should be accounted for in the prediction process. Beyond predicting cleavage efficiencies, the learning process provides inferences regarding patterns that underlie the mechanism of action of the CRISPR-Cas9 system. We discover that attributes that describe the spatial structure and rigidity of the entire genomic site as well as those surrounding the PAM region are a major component of the prediction capabilities.

  15. A machine learning approach for predicting CRISPR-Cas9 cleavage efficiencies and patterns underlying its mechanism of action.

    Directory of Open Access Journals (Sweden)

    Shiran Abadi

    2017-10-01

    Full Text Available The adaptation of the CRISPR-Cas9 system as a genome editing technique has generated much excitement in recent years owing to its ability to manipulate targeted genes and genomic regions that are complementary to a programmed single guide RNA (sgRNA. However, the efficacy of a specific sgRNA is not uniquely defined by exact sequence homology to the target site, thus unintended off-targets might additionally be cleaved. Current methods for sgRNA design are mainly concerned with predicting off-targets for a given sgRNA using basic sequence features and employ elementary rules for ranking possible sgRNAs. Here, we introduce CRISTA (CRISPR Target Assessment, a novel algorithm within the machine learning framework that determines the propensity of a genomic site to be cleaved by a given sgRNA. We show that the predictions made with CRISTA are more accurate than other available methodologies. We further demonstrate that the occurrence of bulges is not a rare phenomenon and should be accounted for in the prediction process. Beyond predicting cleavage efficiencies, the learning process provides inferences regarding patterns that underlie the mechanism of action of the CRISPR-Cas9 system. We discover that attributes that describe the spatial structure and rigidity of the entire genomic site as well as those surrounding the PAM region are a major component of the prediction capabilities.

  16. Evaluation of matrix metalloproteinases-2 (MMP-2) and tissue inhibitors of metalloproteinases-2 (TIMP-2) in oral submucous fibrosis and their correlation with disease severity.

    Science.gov (United States)

    Shrestha, A; Carnelio, S

    2013-01-01

    Oral submucous fibrosis (OSF), a potentially malignant oral lesion, is a form of pathological fibrosis affecting the oral mucosa. It results from an imbalance in equilibrium of the normal process of synthesis and degradation of extra cellular matrix. Matrix metalloproteinases and its inhibitors play important role in remodeling of the extra cellular matrix which are important in progression and pathogenesis of potentially malignant lesions to malignancy. To evaluate the expression and distribution of Matrix metalloproteinases-2 (MMP- 2) and Tissue inhibitor of metalloproteinases-2 (TIMP-2) in different grades of Oral Submucous Fibrosis(OSF). Immunohistochemical analysis for MMP-2 and its TIMP-2 was performed in 30 histopathologically confirmed, formalin fixed, paraffin embedded specimens of OSF. A semi-quantitative analysis was done to assess the expression, distribution and comparison of these in various stages of this disease. All moderately advanced cases and 64.2% for MMP-2 and 78.5% for TIMP-2 of early stage cases showed positivity. Between two stages of OSF, statistically significant differences were noted in expression of TIMP-2 in lamina propria, deep connective tissue and supra basal layers (p<0.05) and basal and supra basal layers for MMP-2 (p<0.05). The simultaneous increase in expression of MMP-2 and TIMP-2 with advancing stages of OSF can provide a basis for considering the proteases as important mediators in the pathogenesis and progression of OSF which could aid in identifying the aggressiveness of the condition and elucidate its role in its malignant transformation.

  17. Matrix metalloproteinase-10 (MMP-10) interaction with tissue inhibitors of metalloproteinases TIMP-1 and TIMP-2: binding studies and crystal structure.

    Science.gov (United States)

    Batra, Jyotica; Robinson, Jessica; Soares, Alexei S; Fields, Alan P; Radisky, Derek C; Radisky, Evette S

    2012-05-04

    Matrix metalloproteinase 10 (MMP-10, stromelysin-2) is a secreted metalloproteinase with functions in skeletal development, wound healing, and vascular remodeling; its overexpression is also implicated in lung tumorigenesis and tumor progression. To understand the regulation of MMP-10 by tissue inhibitors of metalloproteinases (TIMPs), we have assessed equilibrium inhibition constants (K(i)) of putative physiological inhibitors TIMP-1 and TIMP-2 for the active catalytic domain of human MMP-10 (MMP-10cd) using multiple kinetic approaches. We find that TIMP-1 inhibits the MMP-10cd with a K(i) of 1.1 × 10(-9) M; this interaction is 10-fold weaker than the inhibition of the similar MMP-3 (stromelysin-1) catalytic domain (MMP-3cd) by TIMP-1. TIMP-2 inhibits the MMP-10cd with a K(i) of 5.8 × 10(-9) M, which is again 10-fold weaker than the inhibition of MMP-3cd by this inhibitor (K(i) = 5.5 × 10(-10) M). We solved the x-ray crystal structure of TIMP-1 bound to the MMP-10cd at 1.9 Å resolution; the structure was solved by molecular replacement and refined with an R-factor of 0.215 (R(free) = 0.266). Comparing our structure of MMP-10cd·TIMP-1 with the previously solved structure of MMP-3cd·TIMP-1 (Protein Data Bank entry 1UEA), we see substantial differences at the binding interface that provide insight into the differential binding of stromelysin family members to TIMP-1. This structural information may ultimately assist in the design of more selective TIMP-based inhibitors tailored for specificity toward individual members of the stromelysin family, with potential therapeutic applications.

  18. The interaction of the antitoxin DM43 with a snake venom metalloproteinase analyzed by mass spectrometry and surface plasmon resonance

    DEFF Research Database (Denmark)

    Brand, Guilherme D; Salbo, Rune; Jørgensen, Thomas J D

    2012-01-01

    DM43 is a circulating dimeric antitoxin isolated from Didelphis aurita, a South American marsupial naturally immune to snake envenomation. This endogenous inhibitor binds non-covalently to jararhagin, the main hemorrhagic metalloproteinase from Bothrops jararaca snake venom, and efficiently...

  19. Nonselective matrix metalloproteinase but not tumor necrosis factor-a inhibition effectively preserves the early critical colon anastomotic integrity

    DEFF Research Database (Denmark)

    Ågren, Magnus S.; Andersen, Thomas L.; Andersen, Line

    2011-01-01

    Increased matrix metalloproteinase (MMP) activity has been implicated in the pathogenesis of colorectal anastomotic leakage. Tumor necrosis factor-a (TNF-a) induces MMPs and may influence anastomosis repair....

  20. Allele-specific transactivation of matrix metalloproteinase 7 by FOXA2 and correlation with plasma levels in idiopathic pulmonary fibrosis.

    Science.gov (United States)

    Richards, Thomas J; Park, Chunghyun; Chen, Yiliang; Gibson, Kevin F; Peter Di, Y; Pardo, Annie; Watkins, Simon C; Choi, Augustine M K; Selman, Moises; Pilewski, Joseph; Kaminski, Naftali; Zhang, Yingze

    2012-04-15

    Idiopathic pulmonary fibrosis (IPF) is a complex disease with poorly understood etiology. Previously, we reported upregulation of matrix metalloproteinase 7 (MMP7) in both lung and peripheral blood of IPF patients. Here we report evidence for genetic correlation of plasma levels and promoter polymorphisms (rs11568818 and rs11568819) of MMP7 in a well-characterized IPF cohort. Both the AA genotype of rs11568818 and the CT genotype of rs11568819 were found to be significantly associated with higher MMP7 plasma levels. These associations were observed only in IPF patients and not in healthy controls. The G-to-A transition of rs11568818 resulted in a novel binding site for the forkhead box A2 (FOXA2) transcription factor, a key regulator of embryonic lung development and proper function of the mature lung. In vitro, this transition led to increased sensitivity of the MMP7 promoter to FOXA2. In IPF lungs, FOXA2 was localized in the nucleus of epithelial cells that expressed MMP7 in the cytoplasm. These results suggest that increased sensitivity of the polymorphic MMP7 promoter to FOXA2 provides one of the genetic bases for the upregulation of MMP7 in IPF.

  1. Intracellular Wnt/Beta-Catenin Signaling Underlying 17beta-Estradiol-Induced Matrix Metalloproteinase 9 Expression in Human Endometriosis.

    Science.gov (United States)

    Zhang, Ling; Xiong, Wenqian; Xiong, Yao; Liu, Hengwei; Li, Na; Du, Yu; Liu, Yi

    2016-03-01

    Extracellular matrix remodeling is necessary for ectopic endometrium implantation. Many studies have shown an increased expression of matrix metalloproteinase 9 (MMP9) in the ectopic endometrium of endometriosis. However, the signaling pathways and cellular effects related to this process remain incompletely elucidated. The objective of our study was to investigate the association between MMP9 and the Wnt signaling pathway under the regulation of 17beta-estradiol (E2) in endometrial stromal cells. We found that MMP9 was elevated in tissues from women with endometriosis compared with normal women. Furthermore, MMP9 and beta-catenin increased concurrently in a time- and dose-dependent manner after E2 treatment. To clarify the relationship between MMP9 and beta-catenin, we performed luciferase promoter reporter and chromatin immunoprecipitation assays. A beta-catenin/TCF3/LEF1 complex bound to a specific site on the MMP9 promoter that promoted MMP9 gene and protein expression. The promotion of MMP9 by the Wnt signaling pathway under the regulation of E2 may contribute to the pathophysiology of this disease. © 2016 by the Society for the Study of Reproduction, Inc.

  2. Matrix metalloproteinase-9 plays a role in protecting zebrafish from lethal infection with Listeria monocytogenes by enhancing macrophage migration.

    Science.gov (United States)

    Shan, Ying; Zhang, Yikai; Zhuo, Xunhui; Li, Xiaoliang; Peng, Jinrong; Fang, Weihuan

    2016-07-01

    Zebrafish could serve as an alternative animal model for pathogenic bacteria in multiple infectious routes. Our previous study showed that immersion infection in zebrafish with Listeria monocytogenes did not cause lethality but induced transient expression of several immune response genes. We used an Affymetrix gene chip to examine the expression profiles of genes of zebrafish immersion-infected with L. monocytogenes. A total of 239 genes were up-regulated and 56 genes down-regulated compared with uninfected fish. Highest expression (>20-fold) was seen with the mmp-9 gene encoding the matrix metalloproteinase-9 (Mmp-9) known to degrade the extracellular matrix proteins. By morpholino knockdown of mmp-9, we found that the morphants showed rapid death with much higher bacterial load after intravenous or intraventricular (brain ventricle) infection with L. monocytogenes. Macrophages in mmp-9-knockdown morphants had significant defect in migrating to the brain cavity upon intraventricular infection. Decreased migration of murine macrophages with knockdown of mmp-9 and cd44 was also seen in transwell inserts with 8-μm pore polycarbonate membrane, as compared with the scrambled RNA. These findings suggest that Mmp-9 is a protective molecule against infection by L. monocytogenes by engaging in migration of zebrafish macrophages to the site of infection via a non-proteolytic role. Further work is required on the molecular mechanisms governing Mmp-9-driven macrophage migration in zebrafish. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Human tissue inhibitor of metalloproteinases-1 improved wound healing in diabetes through its anti-apoptotic effect.

    Science.gov (United States)

    Lao, Guojuan; Ren, Meng; Wang, Xiaoyi; Zhang, Jinglu; Huang, Yanrui; Liu, Dan; Luo, Hengcong; Yang, Chuan; Yan, Li

    2017-09-08

    Impaired wound healing accompanies severe cell apoptosis in diabetic patients. Tissue inhibitor of metalloproteinases-1 (TIMP-1) was known to have effects on promoting growth and anti-apoptosis for cells. We aimed to determine the actual levels of TIMP-1 and cell apoptosis in: (i) the biopsies of diabetic and non-diabetic foot tissue and (ii) the human fibroblasts with or without treatments of advanced glycation end-products (AGEs). Next, we aimed to determine the improved levels of cell apoptosis and wound healing after the treatments of either active protein of TIMP-1 or in vivo expression of gene therapy vector-mediated TIMP-1 in both the human fibroblasts and the animal model of diabetic rats. The levels of TIMP-1 were significantly reduced in diabetic skin tissues and in AGEs-treated fibroblasts. Both AGEs-treated cells were effectively protected from apoptosis by active protein of TIMP-1 at appropriate dose level. So did the induced in vivo TIMP-1 expression after gene delivery. Similar effects were also found on the significant improvement of impaired wound healing in diabetic rats. We concluded that TIMP-1 improved wound healing through its anti-apoptotic effect. Treatments with either active protein TIMP-1 or TIMP-1 gene therapy delivered in local wound sites may be used as a strategy for accelerating diabetic wound healing. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Antibodies to H2a and H2b histones from the sera of HIV-infected patients catalyze site-specific degradation of these histones.

    Science.gov (United States)

    Baranova, Svetlana V; Dmitrienok, Pavel S; Ivanisenko, Nikita V; Buneva, Valentina N; Nevinsky, Georgy A

    2017-06-01

    Histones and their post-translational modifications have key roles in chromatin remodeling and gene transcription. Besides intranuclear functions, histones act as damage-associated molecules when they are released into the extracellular space. Administration of histones to animals leads to systemic inflammatory and toxic responses. Autoantibodies with enzymatic activities (abzymes) are distinctive features of some autoimmune and viral diseases. Electrophoretically homogeneous IgGs containing no canonical enzymes were isolated from the sera of HIV-infected patients by chromatography on several affinity sorbents including anti-histone Sepharose. In contrast to canonical proteases (trypsin, chymotrypsin, proteinase K), IgGs from HIV-infected patients specifically hydrolyzed only histones but not many other tested globular proteins. Using MALDI mass spectrometry the sites of H2a and H2b histone cleavage by anti-histone IgGs were determined for the first time. One cluster of H2a hydrolysis contains two major (↕) and four moderate (↓) cleavage sites: 31-H↓R↓L↓L↓R↕K G↕N-38. One major and two moderate sites of cleavage were revealed in the second cluster: 14-A↕KSRS↓SRA↓G-22. The third cluster corresponding to the H2a C-terminal part contains only five minor (†) sites of cleavage: 82-H†LQLAIRNDEELN†KLLG†RV†T†I-102. It was shown that two major and four moderate sites of cleavage were present in the main cluster of H2b hydrolysis: 46-K↕QvhpD↓TgiS↓SkA↓M↕GiM↓N-63. Two moderate sites of cleavage correspond to a relatively short 6-mer cluster: 12-K↓GskK↓A-17. The third relatively long 9-mer cluster contains one major and two minor sites of H2b cleavage: 80-L↕AHYN†KRS†T-88. In the nucleosome core particle, most of the major and moderate cleavage sites are located at the H2a/H2b interaction interface. Minor cleavage sites of H2a are involved in binding with H3 in the nucleosome core. Two moderate cleavage sites of H2b and one

  5. Matrix Metalloproteinases Are Differentially Regulated and Responsive to Compression Therapy in a Red Duroc Model of Hypertrophic Scar.

    Science.gov (United States)

    Travis, Taryn E; Ghassemi, Pejhman; Prindeze, Nicholas J; Moffatt, Lauren T; Carney, Bonnie C; Alkhalil, Abdulnaser; Ramella-Roman, Jessica C; Shupp, Jeffrey W

    2018-01-01

    Objective: Proteins of the matrix metalloproteinases family play a vital role in extracellular matrix maintenance and basic physiological processes in tissue homeostasis. The function and activities of matrix metalloproteinases in response to compression therapies have yet to be defined. Here, a swine model of hypertrophic scar was used to profile the transcription of all known 26 matrix metalloproteinases in scars treated with a precise compression dose. Methods: Full-thickness excisional wounds were created. Wounds underwent healing and scar formation. A subset of scars underwent 2 weeks of compression therapy. Biopsy specimens were preserved, and microarrays, reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemistry were performed to characterize the transcription and expression of various matrix metalloproteinase family members. Results: Microarray results showed that 13 of the known 26 matrix metalloproteinases were differentially transcribed in wounds relative to the preinjury skin. The predominant upregulation of these matrix metalloproteinases during early wound-healing stages declined gradually in later stages of wound healing. The use of compression therapy reduced this decline in 10 of the 13 differentially regulated matrix metalloproteinases. Further investigation of MMP7 using reverse transcription-polymerase chain reaction confirmed the effect of compression on transcript levels. Assessment of MMP7 at the protein level using Western blotting and immunohistochemistry was concordant. Conclusions: In a swine model of hypertrophic scar, the application of compression to hypertrophic scar attenuated a trend of decreasing levels of matrix metalloproteinases during the process of hypertrophic wound healing, including MMP7, whose enzyme regulation was confirmed at the protein level.

  6. Cleavage-Independent HIV-1 Trimers From CHO Cell Lines Elicit Robust Autologous Tier 2 Neutralizing Antibodies

    Directory of Open Access Journals (Sweden)

    Shridhar Bale

    2018-05-01

    Full Text Available Native flexibly linked (NFL HIV-1 envelope glycoprotein (Env trimers are cleavage-independent and display a native-like, well-folded conformation that preferentially displays broadly neutralizing determinants. The NFL platform simplifies large-scale production of Env by eliminating the need to co-transfect the precursor-cleaving protease, furin that is required by the cleavage-dependent SOSIP trimers. Here, we report the development of a CHO-M cell line that expressed BG505 NFL trimers at a high level of homogeneity and yields of ~1.8 g/l. BG505 NFL trimers purified by single-step lectin-affinity chromatography displayed a native-like closed structure, efficient recognition by trimer-preferring bNAbs, no recognition by non-neutralizing CD4 binding site-directed and V3-directed antibodies, long-term stability, and proper N-glycan processing. Following negative-selection, formulation in ISCOMATRIX adjuvant and inoculation into rabbits, the trimers rapidly elicited potent autologous tier 2 neutralizing antibodies. These antibodies targeted the N-glycan “hole” naturally present on the BG505 Env proximal to residues at positions 230, 241, and 289. The BG505 NFL trimers that did not expose V3 in vitro, elicited low-to-no tier 1 virus neutralization in vivo, indicating that they remained intact during the immunization process, not exposing V3. In addition, BG505 NFL and BG505 SOSIP trimers expressed from 293F cells, when formulated in Adjuplex adjuvant, elicited equivalent BG505 tier 2 autologous neutralizing titers. These titers were lower in potency when compared to the titers elicited by CHO-M cell derived trimers. In addition, increased neutralization of tier 1 viruses was detected. Taken together, these data indicate that both adjuvant and cell-type expression can affect the elicitation of tier 2 and tier 1 neutralizing responses in vivo.

  7. Force-Induced Calpain Cleavage of Talin Is Critical for Growth, Adhesion Development, and Rigidity Sensing.

    Science.gov (United States)

    Saxena, Mayur; Changede, Rishita; Hone, James; Wolfenson, Haguy; Sheetz, Michael P

    2017-12-13

    Cell growth depends upon formation of cell-matrix adhesions, but mechanisms detailing the transmission of signals from adhesions to control proliferation are still lacking. Here, we find that the scaffold protein talin undergoes force-induced cleavage in early adhesions to produce the talin rod fragment that is needed for cell cycle progression. Expression of noncleavable talin blocks cell growth, adhesion maturation, proper mechanosensing, and the related property of EGF activation of motility. Further, the expression of talin rod in the presence of noncleavable full-length talin rescues cell growth and other functions. The cleavage of talin is found in early adhesions where there is also rapid turnover of talin that depends upon calpain and TRPM4 activity as well as the generation of force on talin. Thus, we suggest that an important function of talin is its control over cell cycle progression through its cleavage in early adhesions.

  8. Cell elongation is an adaptive response for clearing long chromatid arms from the cleavage plane

    Science.gov (United States)

    Kotadia, Shaila; Montembault, Emilie; Sullivan, William

    2012-01-01

    Chromosome segregation must be coordinated with cell cleavage to ensure correct transmission of the genome to daughter cells. Here we identify a novel mechanism by which Drosophila melanogaster neuronal stem cells coordinate sister chromatid segregation with cleavage furrow ingression. Cells adapted to a dramatic increase in chromatid arm length by transiently elongating during anaphase/telophase. The degree of cell elongation correlated with the length of the trailing chromatid arms and was concomitant with a slight increase in spindle length and an enlargement of the zone of cortical myosin distribution. Rho guanine-nucleotide exchange factor (Pebble)–depleted cells failed to elongate during segregation of long chromatids. As a result, Pebble-depleted adult flies exhibited morphological defects likely caused by cell death during development. These studies reveal a novel pathway linking trailing chromatid arms and cortical myosin that ensures the clearance of chromatids from the cleavage plane at the appropriate time during cytokinesis, thus preserving genome integrity. PMID:23185030

  9. Electrostatic instability of some jellium model lattices of high symmetry to their plane cleavage

    International Nuclear Information System (INIS)

    Kholopov, Eugene V; Kalashnikova, Vita V

    2007-01-01

    Jellium model structures composed of regular lattices of equal point charges immersed in a neutralizing uniform background are considered. The symmetric description eliminating the effect of potentials without transverse structural modulation is extended to the events specified by alternating distances between point-charge planes. Based on modulated potentials typical of plane-wise lattice summation, the energy of interaction between two semi-infinite hemi-crystals divided by a plane is obtained for cubic and hexagonal crystals, where all the characteristic orientations of the cleavage plane are taken into account. We found that simple cubic and hexagonal lattices, as well as cubic and hexagonal diamond structures, turn out to be unstable for certain cleavage planes. The most favourable cleavage planes for the bcc, fcc and hcp structures are also emphasized

  10. Effect of microstructure on the cleavage fracture strength of low carbon Mn-Ni-Mo bainitic steels

    International Nuclear Information System (INIS)

    Im, Young-Roc; Lee, Byeong-Joo; Oh, Yong Jun; Hong, Jun Hwa; Lee, Hu-Chul

    2004-01-01

    The effects of the microstructure on the cleavage fracture strength of low carbon Mn-Ni-Mo bainitic steels were examined. A four-point bend test and double-notched bend specimens were used to measure the cleavage fracture strength of the alloys and identify the cleavage initiating micro-cracks, respectively. The cleavage fracture strength and DBTT of Mn-Ni-Mo bainitic steels were strongly affected by the alloy carbon content. The decrease in the alloy carbon content resulted in a decrease in the inter-lath cementite-crowded layers and higher cleavage fracture strength. Micro-cracks that formed across the inter-lath cementite-crowded layers were observed to initiate cleavage fracture. The width of these inter-lath cementite-crowded layers was accepted as a cleavage initiating micro-crack size in the micro-mechanical modeling of the cleavage fracture, and the measured cleavage strength values of the bainitic Mn-Ni-Mo steels were well represented by the modified Griffith relationship

  11. Autoactivation of mouse trypsinogens is regulated by chymotrypsin C via cleavage of the autolysis loop.

    Science.gov (United States)

    Németh, Balázs Csaba; Wartmann, Thomas; Halangk, Walter; Sahin-Tóth, Miklós

    2013-08-16

    Chymotrypsin C (CTRC) is a proteolytic regulator of trypsinogen autoactivation in humans. CTRC cleavage of the trypsinogen activation peptide stimulates autoactivation, whereas cleavage of the calcium binding loop promotes trypsinogen degradation. Trypsinogen mutations that alter these regulatory cleavages lead to increased intrapancreatic trypsinogen activation and cause hereditary pancreatitis. The aim of this study was to characterize the regulation of autoactivation of mouse trypsinogens by mouse Ctrc. We found that the mouse pancreas expresses four trypsinogen isoforms to high levels, T7, T8, T9, and T20. Only the T7 activation peptide was cleaved by mouse Ctrc, causing negligible stimulation of autoactivation. Surprisingly, mouse Ctrc poorly cleaved the calcium binding loop in all mouse trypsinogens. In contrast, mouse Ctrc readily cleaved the Phe-150-Gly-151 peptide bond in the autolysis loop of T8 and T9 and inhibited autoactivation. Mouse chymotrypsin B also cleaved the same peptide bond but was 7-fold slower. T7 was less sensitive to chymotryptic regulation, which involved slow cleavage of the Leu-149-Ser-150 peptide bond in the autolysis loop. Modeling indicated steric proximity of the autolysis loop and the activation peptide in trypsinogen, suggesting the cleaved autolysis loop may directly interfere with activation. We conclude that autoactivation of mouse trypsinogens is under the control of mouse Ctrc with some notable differences from the human situation. Thus, cleavage of the trypsinogen activation peptide or the calcium binding loop by Ctrc is unimportant. Instead, inhibition of autoactivation via cleavage of the autolysis loop is the dominant mechanism that can mitigate intrapancreatic trypsinogen activation.