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Sample records for rhob variant polypeptides

  1. Methods for engineering polypeptide variants via somatic hypermutation and polypeptide made thereby

    Science.gov (United States)

    Tsien, Roger Y; Wang, Lei

    2015-01-13

    Methods using somatic hypermutation (SHM) for producing polypeptide and nucleic acid variants, and nucleic acids encoding such polypeptide variants are disclosed. Such variants may have desired properties. Also disclosed are novel polypeptides, such as improved fluorescent proteins, produced by the novel methods, and nucleic acids, vectors, and host cells comprising such vectors.

  2. Hemoglobin variants as models for investigation of dissociation of intact polypeptide chains by ESI tandem mass spectrometry

    International Nuclear Information System (INIS)

    Light, K.J.; Loo, J.A.; Edmonds, C.G.; Smith, R.D.

    1991-06-01

    Electrospray ionization mass spectroscopy (ESI-MS) is rapidly becoming a practical biochemical tool for peptide and protein sequence analysis. The utility of ESI-MS is through use of Collisionally Activated Dissociation (ESI-CAD-MS). Human hemoglobin (Hb, ∼62 kDa) consists of four polypeptide chains and a prosthetic heme group. There are over 400 Hb variants, characterized by amino acid substitutions in either the alpha or beta polypeptide chains. We investigated ESI-CAD-MS as a tool for rapidly analyzing amino acid substitutions, using eight Hb beta chain variants. The approximate location of the modification can be deduced from comparison of the CAD mass spectra and observance of the mass shifts of the fragment ion containing the substitution. Fragmentation occurs preferentially at the amino terminus of proline residues. For most substitutions, differences in CAD mass spectra were not seen. 2 figs

  3. Radiosensitizing effect of RHOB protein in melanoma cells

    International Nuclear Information System (INIS)

    Notcovich, C.; Grissi, C.; Sánchez Crespo, R.; Delgado, D.C.; Molinari, B.; Ibañez, I.L.; Durán, H.

    2015-01-01

    Melanoma cells are highly resistant to chemo or radiotherapy. DNA damage agents such as ionizing radiation induce apoptosis involving RhoB protein. In a great variety of tumors the levels of this protein decrease along tumor progression. RhoB is considered a tumor suppressor gene due to its antiproliferative and proapoptotic effect. Considering the aforementioned, the aim of this study was to characterize the radiobiological response of different human melanoma cell lines, and to evaluate the possible correlation between RhoB expression and radiosensitivity. The human melanoma cell lines A375, MELJ and SB2 were gamma-irradiated ( 137 Cs). Survival curves were obtained by clonogenic assay and fitted to the Linear-Quadratic (LQ) model. Radiosensitivity was evaluated by surviving fraction at 2 Gy (SF2). Results showed that MELJ was significantly more radioresistant (SF2=0.71) than A375 and SB2 (0.29 and 0.21 respectively. Expression levels of RhoB, evaluated by western blot, increased in all lines vs. non-irradiated control. SB2, the most radiosensitive cells, showed a greater induction (p<0.05) of RhoB. Finally, to study whether RhoB has a radiosensitizing effect, these cell lines were stably transfected with a wild type RhoB construction, a constitutively active RhoB mutant V14, or with the empty plasmid as control. For all cell lines higher expression level of this protein was found in RhoB or V14 transfected cells (p<0.05). Sensitization was evaluated by SF2. Significant radiosensitization was demonstrated in clones derived from A375 and SB2 ((p<0.05), while for MELJ cells, radio-sensitization was only found in clones overexpressing V14. In conclusion, the increase of RhoB in melanoma cell lines, either by radiation or transfection has a radiosensitizing effect. Thus, we propose RhoB modulation as a potential therapeutic tool to improve the radiation response of radioresistant melanoma. (authors)

  4. Heterogeneity of rabbit endogenous pyrogens is not attributable to glycosylated variants of a single polypeptide chain.

    OpenAIRE

    Murphy, P A; Cebula, T A; Windle, B E

    1981-01-01

    Rabbit endogenous pyrogens were of about the same molecular size, but showed considerable heterogeneity of their isoelectric points. We attempted to show that this heterogeneity was attributable to variable glycosylation of a single polypeptide chain. When peritoneal exudate cells were stimulated to make pyrogens in the presence of 2-deoxy-D-glucose, there was a relatively trivial suppression of pyrogen release, and analysis by isoelectric focusing showed parallel inhibition of secretion of a...

  5. Heterogeneity of rabbit endogenous pyrogens is not attributable to glycosylated variants of a single polypeptide chain.

    Science.gov (United States)

    Murphy, P A; Cebula, T A; Windle, B E

    1981-10-01

    Rabbit endogenous pyrogens were of about the same molecular size, but showed considerable heterogeneity of their isoelectric points. We attempted to show that this heterogeneity was attributable to variable glycosylation of a single polypeptide chain. When peritoneal exudate cells were stimulated to make pyrogens in the presence of 2-deoxy-D-glucose, there was a relatively trivial suppression of pyrogen release, and analysis by isoelectric focusing showed parallel inhibition of secretion of all the forms of endogenous pyrogen. When cells were stimulated in the presence of 3H-labeled amino acids and 14C-labeled glucosamine or glucose, the purified pyrogens were labeled with 3H but not with 14C. Macrophage membrane preparations were made which contained glycosyl transferases and could transfer sugar residues from sugar nucleotides to deglycosylated fetuin. These macrophage membrane preparations did not transfer sugars to the pI 7.3 endogenous pyrogen. Treatment of endogenous pyrogens with neuraminidase or with periodate produced no evidence suggesting that the pyrogens were glycosylated. Last, endogenous pyrogens did not bind to any of four lectins with different carbohydrate specificities. This evidence suggests that the heterogeneity of rabbit endogenous pyrogens is not attributable to glycosylation and must have some other cause.

  6. The activation of p38 MAPK primarily contributes to UV-induced RhoB expression by recruiting the c-Jun and p300 to the distal CCAAT box of the RhoB promoter

    International Nuclear Information System (INIS)

    Ahn, Jiwon; Choi, Jeong-Hae; Won, Misun; Kang, Chang-Mo; Gyun, Mi-Rang; Park, Hee-Moon; Kim, Chun-Ho; Chung, Kyung-Sook

    2011-01-01

    Highlights: → Regulation of transcriptional activation of RhoB is still unclear. → We examine the effect of p38 MAPK inhibition, and c-Jun and RhoB depletion on UV-induced RhoB expression and apoptosis. → We identify the regions of RhoB promoter necessary to confer UV responsiveness using pRhoB-luciferase reporter assays. → c-Jun, ATF2 and p300 are dominantly associated with NF-Y on the distal CCAAT box. → The activation of p38 MAPK primarily contribute to UV-induced RhoB expression by recruiting the c-Jun and p300 proteins on distal CCAAT box of RhoB promoter. -- Abstract: The Ras-related small GTP-binding protein RhoB is rapidly induced in response to genotoxic stresses caused by ionizing radiation. It is known that UV-induced RhoB expression results from the binding of activating transcription factor 2 (ATF2) via NF-Y to the inverted CCAAT box (-23) of the RhoB promoter. Here, we show that the association of c-Jun with the distal CCAAT box (-72) is primarily involved in UV-induced RhoB expression and p38 MAPK regulated RhoB induction through the distal CCAAT box. UV-induced RhoB expression and apoptosis were markedly attenuated by pretreatment with the p38 MAPK inhibitor. siRNA knockdown of RhoB, ATF2 and c-Jun resulted in decreased RhoB expression and eventually restored the growth of UV-irradiated Jurkat cells. In the reporter assay using luciferase under the RhoB promoter, inhibition of RhoB promoter activity by the p38 inhibitor and knockdown of c-Jun using siRNA occurred through the distal CCAAT box. Immunoprecipitation and DNA affinity protein binding assays revealed the association of c-Jun and p300 via NF-YA and the dissociation of histone deacetylase 1 (HDAC1) via c-Jun recruitment to the CCAAT boxes of the RhoB promoter. These results suggest that the activation of p38 MAPK primarily contributes to UV-induced RhoB expression by recruiting the c-Jun and p300 proteins to the distal CCAAT box of the RhoB promoter in Jurkat cells.

  7. Expression loss and revivification of RhoB gene in ovary carcinoma carcinogenesis and development.

    Science.gov (United States)

    Liu, Yingwei; Song, Na; Ren, Kexing; Meng, Shenglan; Xie, Yao; Long, Qida; Chen, Xiancheng; Zhao, Xia

    2013-01-01

    RhoB, a member of small GTPases belonging to the Ras protein superfamily, might have a suppressive activity in cancer progression. Here, expression of RhoB gene was evaluated in human benign, borderline and malignant ovary tumors by immunostaining, with normal ovary tissue as control. Malignant tumors were assessed according to Federation Internationale de Gynecologie Obstetrique (FIGO) guidelines and classified in stage I-IV. Revivification of RhoB gene was investigated by analyzing the effect of histone deacetylase (HDAC) inhibitor trichostatin (TSA) and methyltransferase inhibitor 5-azacytidine (5-Aza) on ovarian cancer cells via RT-PCR and western blot. Apoptosis of ovary cancer cells was detected using flowcytometry and fluorescence microscopy. Subsequently, RhoB expression is detected in normal ovary epithelium, borderline tumors, and decreases significantly or lost in the majority of ovarian cancer specimen (Pcancer cells, but 5-Aza couldn't. Interference into Revivification of RhoB gene results in reduction of ovary carcinoma cell apoptosis. It is proposed that loss of RhoB expression occurs frequently in ovary carcinogenesis and progression and its expression could be regulated by histone deacetylation but not by promoter hypermethylation, which may serve as a prospective gene treatment target for the patients with ovarian malignancy not responding to standard therapies.

  8. Affinity purification of human factor H on polypeptides derived from streptococcal m protein: enrichment of the Y402 variant.

    Directory of Open Access Journals (Sweden)

    O Rickard Nilsson

    Full Text Available Recent studies indicate that defective activity of complement factor H (FH is associated with several human diseases, suggesting that pure FH may be used for therapy. Here, we describe a simple method to isolate human FH, based on the specific interaction between FH and the hypervariable region (HVR of certain Streptococcus pyogenes M proteins. Special interest was focused on the FH polymorphism Y402H, which is associated with the common eye disease age-related macular degeneration (AMD and has also been implicated in the binding to M protein. Using a fusion protein containing two copies of the M5-HVR, we found that the Y402 and H402 variants of FH could be efficiently purified by single-step affinity chromatography from human serum containing the corresponding protein. Different M proteins vary in their binding properties, and the M6 and M5 proteins, but not the M18 protein, showed selective binding of the FH Y402 variant. Accordingly, chromatography on a fusion protein derived from the M6-HVR allowed enrichment of the Y402 protein from serum containing both variants. Thus, the exquisite binding specificity of a bacterial protein can be exploited to develop a simple and robust procedure to purify FH and to enrich for the FH variant that protects against AMD.

  9. RhoB mediates antitumor synergy of combined ixabepilone and sunitinib in human ovarian serous cancer.

    Science.gov (United States)

    Vishnu, Prakash; Colon-Otero, Gerardo; Kennedy, Gregory T; Marlow, Laura A; Kennedy, William P; Wu, Kevin J; Santoso, Joseph T; Copland, John A

    2012-03-01

    The aim was to evaluate antitumor activity of the combination of ixabepilone and sunitinib in pre-clinical models of chemotherapy naïve and refractory epithelial ovarian tumors, and to investigate the mechanism of synergy of such drug combination. HOVTAX2 cell line was derived from a metastatic serous papillary epithelial ovarian tumor (EOC) and a paclitaxel-resistant derivative was established. Dose response curves for ixabepilone and sunitinib were generated and synergy was determined using combination indexes. The molecular mechanism of antitumor synergy was examined using shRNA silencing. The combination of ixabepilone and sunitinib demonstrated robust antitumor synergy in naïve and paclitaxel-resistant HOVTAX2 cell lines due to increased apoptosis. The GTPase, RhoB, was synergistically upregulated in cells treated with ixabepilone and sunitinib. Using shRNA, RhoB was demonstrated to mediate antitumor synergy. These results were validated in two other EOC cell lines. Ixabepilone plus sunitinib demonstrated antitumor synergy via RhoB in naïve and paclitaxel-resistant cells resulting in apoptosis. This study demonstrates a novel mechanism of action leading to antitumor synergy and provides 'proof-of-principle' for combining molecular targeted agents with cytotoxic chemotherapy to improve antitumor efficacy. RhoB could be envisioned as an early biomarker of response to therapy in a planned Phase II clinical trial to assess the efficacy of ixabepilone combined with a receptor tyrosine kinase inhibitor such as sunitinib. To the best of our knowledge, this is the first demonstration of antitumor synergy between these two classes of drugs in EOC and the pivotal role of RhoB in this synergy. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Rnd3 induces stress fibres in endothelial cells through RhoB

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    Undine Gottesbühren

    2012-12-01

    Rnd proteins are atypical Rho family proteins that do not hydrolyse GTP and are instead regulated by expression levels and post-translational modifications. Rnd1 and Rnd3/RhoE induce loss of actin stress fibres and cell rounding in multiple cell types, whereas responses to Rnd2 are more variable. Here we report the responses of endothelial cells to Rnd proteins. Rnd3 induces a very transient decrease in stress fibres but subsequently stimulates a strong increase in stress fibres, in contrast to the reduction observed in other cell types. Rnd2 also increases stress fibres whereas Rnd1 induces a loss of stress fibres and weakening of cell–cell junctions. Rnd3 does not act through any of its known signalling partners and does not need to associate with membranes to increase stress fibres. Instead, it acts by increasing RhoB expression, which is then required for Rnd3-induced stress fibre assembly. Rnd2 also increases RhoB levels. These data indicate that the cytoskeletal response to Rnd3 expression is dependent on cell type and context, and identify regulation of RhoB as a new mechanism for Rnd proteins to affect the actin cytoskeleton.

  11. Loss of RhoB expression enhances the myelodysplastic phenotype of mammalian diaphanous-related Formin mDia1 knockout mice.

    Directory of Open Access Journals (Sweden)

    Aaron D DeWard

    Full Text Available Myelodysplastic syndrome (MDS is characterized by ineffective hematopoiesis and hyperplastic bone marrow. Complete loss or interstitial deletions of the long arm of chromosome 5 occur frequently in MDS. One candidate tumor suppressor on 5q is the mammalian Diaphanous (mDia-related formin mDia1, encoded by DIAPH1 (5q31.3. mDia-family formins act as effectors for Rho-family small GTP-binding proteins including RhoB, which has also been shown to possess tumor suppressor activity. Mice lacking the Drf1 gene that encodes mDia1 develop age-dependent myelodysplastic features. We crossed mDia1 and RhoB knockout mice to test whether the additional loss of RhoB expression would compound the myelodysplastic phenotype. Drf1(-/-RhoB(-/- mice are fertile and develop normally. Relative to age-matched Drf1(-/-RhoB(+/- mice, the age of myelodysplasia onset was earlier in Drf1(-/-RhoB(-/- animals--including abnormally shaped erythrocytes, splenomegaly, and extramedullary hematopoiesis. In addition, we observed a statistically significant increase in the number of activated monocytes/macrophages in both the spleen and bone marrow of Drf1(-/-RhoB(-/- mice relative to Drf1(-/-RhoB(+/- mice. These data suggest a role for RhoB-regulated mDia1 in the regulation of hematopoietic progenitor cells.

  12. Radiation of different human melanoma cell lines increased expression of RHOB. Level of this tumor suppressor gene in different cell lines

    International Nuclear Information System (INIS)

    Notcovich, C.; Molinari, B.; Duran, H.; Delgado González, D.; Sánchez Crespo, R.

    2013-01-01

    Previous results of our group show that a correlation exists between intrinsic radiosensitivity of human melanoma cells and cell death by apoptosis. RhoB is a small GTPase that regulates cytoskeletal organization. Besides, is related to the process of apoptosis in cells exposed to DNA damage as radiation. Also, RhoB levels decrease in a wide variety of tumors with the tumor stage, being considered a tumor suppressor gene due to its antiproliferative and proapoptotic effect. The aim of this study was to analyze the expression of RhoB in different human melanoma cell lines in relation to melanocytes, and evaluate the effect of gamma radiation on the expression of RhoB. We used the A375, SB2 and Meljcell lines, and the derived from melanocytes Pig1. It was found for all three tumor lines RhoB expression levels significantly lower than those of Pig1 (p <0.05), as assessed by semiquantitative RT-PCR . When tumor cells were irradiated to a dose of 2Gyinduction was observed at 3 hours RhoB irradiation. RhoB expression increased in all lines relative to non-irradiated control, showing a greater induction ( p< 0.05) for the more radiosensitive line SB2, consistent with apoptosis in response to radiation. The results allow for the first time in melanoma demonstrate that RhoB, as well as in other tumor types, has a lower expression in tumor cells than their normal counterparts. Moreover, induction in the expression of RhoB in irradiated cells may be associated with the process of radiation-induced apoptosis. The modulation of RhoB could be a new tool to sensitize radioresistant melanoma. (author)

  13. Expression and cytoprotective activity of the small GTPase RhoB induced by the Escherichia coli cytotoxic necrotizing factor 1

    DEFF Research Database (Denmark)

    Huelsenbeck, Stefanie C; Roggenkamp, Dennis; May, Martin

    2013-01-01

    B expression, based on the inactivation of Rho/Ras proteins. In this study, we report on a long lasting expression of RhoB in cultured cells upon activation of Rho proteins by the cytotoxic necrotizing factor 1 (CNF1) from Escherichia coli. The observations of this study highlight a new pathway involving Rac1...... without any signs of cell death. In conclusion, the cytoprotective RhoB response is not only evoked by bacterial protein toxins inactivating Rho/Ras proteins but also by the Rac1-activating toxin CNF1....

  14. Differential binding of RhoA, RhoB, and RhoC to protein kinase C-related kinase (PRK) isoforms PRK1, PRK2, and PRK3: PRKs have the highest affinity for RhoB.

    Science.gov (United States)

    Hutchinson, Catherine L; Lowe, Peter N; McLaughlin, Stephen H; Mott, Helen R; Owen, Darerca

    2013-11-12

    Protein kinase C-related kinases (PRKs) are members of the protein kinase C superfamily of serine-threonine kinases and can be activated by binding to members of the Rho family of GTPases via a Rho-binding motif known as an HR1 domain. Three tandem HR1 domains reside at the N-terminus of the PRKs. We have assessed the ability of the HR1a and HR1b domains from the three PRK isoforms (PRK1, PRK2, and PRK3) to interact with the three Rho isoforms (RhoA, RhoB, and RhoC). The affinities of RhoA and RhoC for a construct encompassing both PRK1 HR1 domains were similar to those for the HR1a domain alone, suggesting that these interactions are mediated solely by the HR1a domain. The affinities of RhoB for both the PRK1 HR1a domain and the HR1ab didomain were higher than those of RhoA or RhoC. RhoB also bound more tightly to the didomain than to the HR1a domain alone, implicating the HR1b domain in the interaction. As compared with PRK1 HR1 domains, PRK2 and PRK3 domains bind less well to all Rho isoforms. Uniquely, however, the PRK3 domains display a specificity for RhoB that requires both the C-terminus of RhoB and the PRK3 HR1b domain. The thermal stability of the HR1a and HR1b domains was also investigated. The PRK2 HR1a domain was found to be the most thermally stable, while PRK2 HR1b, PRK3 HR1a, and PRK3 HR1b domains all exhibited lower melting temperatures, similar to that of the PRK1 HR1a domain. The lower thermal stability of the PRK2 and PRK3 HR1b domains may impart greater flexibility, driving their ability to interact with Rho isoforms.

  15. Mouse macrophages completely lacking Rho (RhoA, RhoB and RhoC) have severe lamellipodial retraction defects, but robust chemotactic navigation and increased motility

    DEFF Research Database (Denmark)

    Koenigs, Volker; Jennings, Richard; Vogl, Thomas

    2014-01-01

    RhoA is thought to be essential for coordination of the membrane protrusions and retractions required for immune cell motility and directed migration. Whether the subfamily of Rho (Ras homolog) GTPases (RhoA, RhoB and RhoC) is actually required for the directed migration of primary cells is diffi...

  16. Polypeptide based hydrogels

    OpenAIRE

    Hanay, Saltuk

    2018-01-01

    There is a need for biocompatible, biodegradable, 3-D printable and stable hydrogels especially in the areas of tissue engineering, drug delivery, bio-sensing technologies and antimicrobial coatings. The main aim of this Ph.D. work was to fabricate polypeptide based hydrogel which may find a potential application in those fields. Focusing on tyrosine or tryptophan-containing copolypeptides prepared by NCarboxyanhydride (NCA) polymerizations, three different crosslinking strategies have been t...

  17. The Role of RhoA, RhoB and RhoC GTPases in Cell Morphology, Proliferation and Migration in Human Cytomegalovirus (HCMV Infected Glioblastoma Cells

    Directory of Open Access Journals (Sweden)

    Melpomeni Tseliou

    2016-01-01

    Full Text Available Background/Aims: Rho GTPases are crucial regulators of the actin cytoskeleton, membrane trafficking and cell signaling and their importance in cell migration and invasion is well- established. The human cytomegalovirus (HCMV is a widespread pathogen responsible for generally asymptomatic and persistent infections in healthy people. Recent evidence indicates that HCMV gene products are expressed in over 90% of malignant type glioblastomas (GBM. In addition, the HCMV Immediate Early-1 protein (IE1 is expressed in >90% of tumors analyzed. Methods: RhoA, RhoB and RhoC were individually depleted in U373MG glioblastoma cells as well as U373MG cells stably expressing the HCMV IE1 protein (named U373MG-IE1 cells shRNA lentivirus vectors. Cell proliferation assays, migration as well as wound-healing assays were performed in uninfected and HCMV-infected cells. Results: The depletion of RhoA, RhoB and RhoC protein resulted in significant alterations in the morphology of the uninfected cells, which were further enhanced by the cytopathic effect caused by HCMV. Furthermore, in the absence or presence of HCMV, the knockdown of RhoB and RhoC proteins decreased the proliferation rate of the parental and the IE1-expressing glioblastoma cells, whereas the knockdown of RhoA protein in the HCMV infected cell lines restored their proliferation rate. In addition, wound healing assays in U373MG cells revealed that depletion of RhoA, RhoB and RhoC differentially reduced their migration rate, even in the presence or the absence of HCMV. Conclusion: Collectively, these data show for the first time a differential implication of Rho GTPases in morphology, proliferation rate and motility of human glioblastoma cells during HCMV infection, further supporting an oncomodulatory role of HCMV depending on the Rho isoforms' state.

  18. Mosaic HIV envelope immunogenic polypeptides

    Science.gov (United States)

    Korber, Bette T. M.; Gnanakaran, S.; Perkins, Simon; Sodroski, Joseph; Haynes, Barton

    2018-01-02

    Disclosed herein are mosaic HIV envelope (Env) polypeptides that can elicit an immune response to HIV (such as cytotoxic T cell (CTL), helper T cell, and/or humoral responses). Also disclosed are sets of the disclosed mosaic Env polypeptides, which include two or more (for example, three) of the polypeptides. Also disclosed herein are methods for treating or inhibiting HIV in a subject including administering one or more of the disclosed immunogenic polypeptides or compositions to a subject infected with HIV or at risk of HIV infection. In some embodiments, the methods include inducing an immune response to HIV in a subject comprising administering to the subject at least one (such as two, three, or more) of the immunogenic polypeptides or at least one (such as two, three, or more) nucleic acids encoding at least one of the immunogenic polypeptides disclosed herein.

  19. Gallic acid inhibits gastric cancer cells metastasis and invasive growth via increased expression of RhoB, downregulation of AKT/small GTPase signals and inhibition of NF-κB activity

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Hsieh-Hsun [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan (China); Chang, Chi-Sen [Department of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Division of Gastroenterology, Taichung Veterans General Hospital, Taichung 402, Taiwan (China); Ho, Wei-Chi [Division of Gastroenterology, Jen-Ai Hospital, Taichung 402, Taiwan (China); Liao, Sheng-You [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan (China); Lin, Wea-Lung [Department of Pathology, School of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Pathology, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Wang, Chau-Jong, E-mail: wcj@csmu.edu.tw [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Medical Research, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China)

    2013-01-01

    Our previous study demonstrated the therapeutic potential of gallic acid (GA) for controlling tumor metastasis through its inhibitory effect on the motility of AGS cells. A noteworthy finding in our previous experiment was increased RhoB expression in GA-treated cells. The aim of this study was to evaluate the role of RhoB expression on the inhibitory effects of GA on AGS cells. By applying the transfection of RhoB siRNA into AGS cells and an animal model, we tested the effect of GA on inhibition of tumor growth and RhoB expression. The results confirmed that RhoB-siRNA transfection induced GA to inhibit AGS cells’ invasive growth involving blocking the AKT/small GTPase signals pathway and inhibition of NF-κB activity. Finally, we evaluated the effect of GA on AGS cell metastasis by colonization of tumor cells in nude mice. It showed GA inhibited tumor cells growth via the expression of RhoB. These data support the inhibitory effect of GA which was shown to inhibit gastric cancer cell metastasis and invasive growth via increased expression of RhoB, downregulation of AKT/small GTPase signals and inhibition of NF-κB activity. Thus, GA might be a potential agent in treating gastric cancer. Highlights: ► GA could downregulate AKT signal via increased expression of RhoB. ► GA inhibits metastasis in vitro in gastric carcinoma. ► GA inhibits tumor growth in nude mice model.

  20. Radiolysis of polypeptide

    International Nuclear Information System (INIS)

    Ogura, Isao; Nakamura, Katsuichi; Tanaka, Hiroshi; Takahashi, Katsuhiro; Ozaki, Makoto

    1981-01-01

    Almost the same results were obtained from the additional dipeptide, Gly-DL-Ala and DL-Ala-DL-Phe, by the γ-irradiation as previous report. Tri and tetrapeptide consisted of the same amino acid signified good stability than the others. Every polypeptide composed from sulfur contained amino acid exhaled the smell of hydrogen sulfide by the irradiation. It seemed that the stability by the difference of position of amino group in amino acid increased in order α, β, γ ... amino acid and that by the existence of hydroxyl group became smaller. (author)

  1. Methods for using polypeptides having cellobiohydrolase activity

    Science.gov (United States)

    Morant, Marc D; Harris, Paul

    2016-08-23

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  2. Islet Amyloid Polypeptide: Structure, Function, and Pathophysiology

    Directory of Open Access Journals (Sweden)

    Rehana Akter

    2016-01-01

    Full Text Available The hormone islet amyloid polypeptide (IAPP, or amylin plays a role in glucose homeostasis but aggregates to form islet amyloid in type-2 diabetes. Islet amyloid formation contributes to β-cell dysfunction and death in the disease and to the failure of islet transplants. Recent work suggests a role for IAPP aggregation in cardiovascular complications of type-2 diabetes and hints at a possible role in type-1 diabetes. The mechanisms of IAPP amyloid formation in vivo or in vitro are not understood and the mechanisms of IAPP induced β-cell death are not fully defined. Activation of the inflammasome, defects in autophagy, ER stress, generation of reactive oxygen species, membrane disruption, and receptor mediated mechanisms have all been proposed to play a role. Open questions in the field include the relative importance of the various mechanisms of β-cell death, the relevance of reductionist biophysical studies to the situation in vivo, the molecular mechanism of amyloid formation in vitro and in vivo, the factors which trigger amyloid formation in type-2 diabetes, the potential role of IAPP in type-1 diabetes, the development of clinically relevant inhibitors of islet amyloidosis toxicity, and the design of soluble, bioactive variants of IAPP for use as adjuncts to insulin therapy.

  3. Polypeptides having catalase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ye; Duan, Junxin; Zhang, Yu; Tang, Lan

    2017-05-02

    Provided are isolated polypeptides having catalase activity and polynucleotides encoding the polypeptides. Also provided are nucleic acid constructs, vectors and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  4. Polypeptides having xylanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj

    2018-02-06

    The present invention relates to isolated polypeptides having xylanase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  5. Glucose-dependent Insulinotropic Polypeptide

    DEFF Research Database (Denmark)

    Christensen, Mikkel B; Calanna, Salvatore; Holst, Jens Juul

    2014-01-01

    CONTEXT: Patients with type 2 diabetes mellitus (T2DM) have clinically relevant disturbances in the effects of the hormone glucose-dependent insulinotropic polypeptide (GIP). OBJECTIVE: We aimed to evaluate the importance of the prevailing plasma glucose levels for the effect of GIP on responses......: During fasting glycemia (plasma glucose ∼8 mmol/L), GIP elicited significant increments in both insulin and glucagon levels, resulting in neutral effects on plasma glucose. During insulin-induced hypoglycemia (plasma glucose ∼3 mmol/L), GIP elicited a minor early-phase insulin response and increased...... glucagon levels during the initial 30 minutes, resulting in less glucose needed to be infused to maintain the clamp (29 ± 8 vs 49 ± 12 mg × kg(-1), P glucose ∼12 mmol/L), GIP augmented insulin secretion throughout the clamp, with slightly less glucagon...

  6. Involvement of Chromatin Remodeling Genes and the Rho GTPases RhoB and CDC42 in Ovarian Clear Cell Carcinoma

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    Nicolai Skovbjerg Arildsen

    2017-05-01

    Full Text Available ObjectiveOvarian clear cell carcinomas (OCCCs constitute a rare ovarian cancer subtype with distinct clinical features, but may nonetheless be difficult to distinguish morphologically from other subtypes. There is limited knowledge of genetic events driving OCCC tumorigenesis beyond ARID1A, which is reportedly mutated in 30–50% of OCCCs. We aimed to further characterize OCCCs by combined global transcriptional profiling and targeted deep sequencing of a panel of well-established cancer genes. Increased knowledge of OCCC-specific genetic aberrations may help in guiding development of targeted treatments and ultimately improve patient outcome.MethodsGene expression profiling of formalin-fixed, paraffin-embedded (FFPE tissue from a cohort of the major ovarian cancer subtypes (cohort 1; n = 67 was performed using whole-genome cDNA-mediated Annealing, Selection, extension and Ligation (WG-DASL bead arrays, followed by pathway, gene module score, and gene ontology analyses, respectively. A second FFPE cohort of 10 primary OCCCs was analyzed by targeted DNA sequencing of a panel of 60 cancer-related genes (cohort 2. Non-synonymous and non-sense variants affecting single-nucleotide variations and insertions or deletions were further analyzed. A tissue microarray of 43 OCCCs (cohort 3 was used for validation by immunohistochemistry and chromogenic in situ hybridization.ResultsGene expression analyses revealed a distinct OCCC profile compared to other histological subtypes, with, e.g., ERBB2, TFAP2A, and genes related to cytoskeletal actin regulation being overexpressed in OCCC. ERBB2 was, however, not overexpressed on the protein level and ERBB2 amplification was rare in the validation cohort. Targeted deep sequencing revealed non-synonymous variants or insertions/deletions in 11/60 cancer-related genes. Genes involved in chromatin remodeling, including ARID1A, SPOP, and KMT2D were frequently mutated across OCCC tumors.ConclusionOCCCs appear

  7. Coulomb repulsion in short polypeptides.

    Science.gov (United States)

    Norouzy, Amir; Assaf, Khaleel I; Zhang, Shuai; Jacob, Maik H; Nau, Werner M

    2015-01-08

    Coulomb repulsion between like-charged side chains is presently viewed as a major force that impacts the biological activity of intrinsically disordered polypeptides (IDPs) by determining their spatial dimensions. We investigated short synthetic models of IDPs, purely composed of ionizable amino acid residues and therefore expected to display an extreme structural and dynamic response to pH variation. Two synergistic, custom-made, time-resolved fluorescence methods were applied in tandem to study the structure and dynamics of the acidic and basic hexapeptides Asp6, Glu6, Arg6, Lys6, and His6 between pH 1 and 12. (i) End-to-end distances were obtained from the short-distance Förster resonance energy transfer (sdFRET) from N-terminal 5-fluoro-l-tryptophan (FTrp) to C-terminal Dbo. (ii) End-to-end collision rates were obtained for the same peptides from the collision-induced fluorescence quenching (CIFQ) of Dbo by FTrp. Unexpectedly, the very high increase of charge density at elevated pH had no dynamical or conformational consequence in the anionic chains, neither in the absence nor in the presence of salt, in conflict with the common view and in partial conflict with accompanying molecular dynamics simulations. In contrast, the cationic peptides responded to ionization but with surprising patterns that mirrored the rich individual characteristics of each side chain type. The contrasting results had to be interpreted, by considering salt screening experiments, N-terminal acetylation, and simulations, in terms of an interplay of local dielectric constant and peptide-length dependent side chain charge-charge repulsion, side chain functional group solvation, N-terminal and side chain charge-charge repulsion, and side chain-side chain as well as side chain-backbone interactions. The common picture that emerged is that Coulomb repulsion between water-solvated side chains is efficiently quenched in short peptides as long as side chains are not in direct contact with each

  8. Glucose oxidase variants with improved properities

    OpenAIRE

    Fischer, Rainer; Ostafe, Raluca; Prodanovic, Radivoje

    2014-01-01

    Source: WO14173822A3 [EN] The technology provided herein relates to novel variants of microbial glucose oxidase with improved properties, more specifically to polypeptides having glucose oxidase activity as their major enzymatic activity; to nucleic acid molecules encoding said glucose oxidases; vectors and host cells containing the nucleic acids and methods for producing the glucose oxidase; compositions comprising said glucose oxidase; methods for the preparation and production of such enzy...

  9. Cellulase variants

    Science.gov (United States)

    Blazej, Robert; Toriello, Nicholas; Emrich, Charles; Cohen, Richard N.; Koppel, Nitzan

    2015-07-14

    This invention provides novel variant cellulolytic enzymes having improved activity and/or stability. In certain embodiments the variant cellulotyic enzymes comprise a glycoside hydrolase with or comprising a substitution at one or more positions corresponding to one or more of residues F64, A226, and/or E246 in Thermobifida fusca Cel9A enzyme. In certain embodiments the glycoside hydrolase is a variant of a family 9 glycoside hydrolase. In certain embodiments the glycoside hydrolase is a variant of a theme B family 9 glycoside hydrolase.

  10. Method of generating ploynucleotides encoding enhanced folding variants

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, Andrew M.; Kiss, Csaba; Waldo, Geoffrey S.

    2017-05-02

    The invention provides directed evolution methods for improving the folding, solubility and stability (including thermostability) characteristics of polypeptides. In one aspect, the invention provides a method for generating folding and stability-enhanced variants of proteins, including but not limited to fluorescent proteins, chromophoric proteins and enzymes. In another aspect, the invention provides methods for generating thermostable variants of a target protein or polypeptide via an internal destabilization baiting strategy. Internally destabilization a protein of interest is achieved by inserting a heterologous, folding-destabilizing sequence (folding interference domain) within DNA encoding the protein of interest, evolving the protein sequences adjacent to the heterologous insertion to overcome the destabilization (using any number of mutagenesis methods), thereby creating a library of variants. The variants in the library are expressed, and those with enhanced folding characteristics selected.

  11. GLYCOSYLATED YGHJ POLYPEPTIDES FROM ENTEROTOXIGENIC ESCHERICHIA COLI (ETEC)

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to glycosylated YghJ polypeptides from or derived from enterotoxigenic Escherichia coli (ETEC) that are immunogenic. In particular, the present invention relates to compositions or vaccines comprising the polypeptides and their application in immunization, vaccination...

  12. Tuning Ice Nucleation with Supercharged Polypeptides

    NARCIS (Netherlands)

    Yang, Huige; Ma, Chao; Li, Kaiyong; Liu, Kai; Loznik, Mark; Teeuwen, Rosalie; van Hest, Jan C. M.; Zhou, Xin; Herrmann, Andreas; Wang, Jianjun

    2016-01-01

    Supercharged unfolded polypeptides (SUPs) are exploited for controlling ice nucleation via tuning the nature of charge and charge density of SUPs. The results show that positively charged SUPs facilitate ice nucleation, while negatively charged ones suppress it. Moreover, the charge density of the

  13. Chimeric polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Science.gov (United States)

    Wogulis, Mark; Sweeney, Matthew; Heu, Tia

    2017-06-14

    The present invention relates to chimeric GH61 polypeptides having cellulolytic enhancing activity. The present invention also relates to polynucleotides encoding the chimeric GH61 polypeptides; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the chimeric GH61 polypeptides.

  14. Polypeptides having xylanase activity and polynucleotides encoding same

    Energy Technology Data Exchange (ETDEWEB)

    Spodsberg, Nikolaj; Shaghasi, Tarana

    2017-06-20

    The present invention relates to polypeptides having xylanase activity, catalytic domains, and carbohydrate binding domains, and polynucleotides encoding the polypeptides, catalytic domains, and carbohydrate binding domains. The present invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides, catalytic domains, and carbohydrate binding domains.

  15. Phase transitions in polypeptides: analysis of energy fluctuations

    DEFF Research Database (Denmark)

    Yakubovich, Alexander V.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2009-01-01

    The helix random coil transition in alanine, valine, and leucine polypeptides consisting of 30 amino acids is studied in vacuo using the Langevin molecular dynamics approach. The influence of side chain radicals on internal energy and heat capacity of the polypeptides is discussed. The heat...... of simulation time. This study provides a comparison of methods for the description of structural transitions in polypeptides....

  16. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    Science.gov (United States)

    Harris, Paul; Golightly, Elizabeth

    2012-11-27

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  17. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    Science.gov (United States)

    Morant, Marc D.; Harris, Paul

    2015-10-13

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  18. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    Science.gov (United States)

    Maiyuran, Suchindra; Kramer, Randall; Harris, Paul

    2013-10-29

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  19. Polynucleotides encoding polypeptides having beta-glucosidase activity

    Science.gov (United States)

    Harris, Paul; Golightly, Elizabeth

    2010-03-02

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  20. Measles virus polypeptides in purified virions and in infected cells

    International Nuclear Information System (INIS)

    Vainionpaeae, R.; Ziola, B.; Salmi, A.

    1978-01-01

    A wild-type measles virus was radiolabeled during growth in VERO cells and purified by two successive potassium tartrate gradient centrifugations. The virion polypeptide composition was determined by SDS-polyacrylamide gel electrophoresis employing two different buffer systems. Six virus-specific polypeptides were consistently detected. The largest (L) had a molecular weight (MW) of greater than 150,000. The second largest polypeptide, G (MW 79,000), was the only glycoprotein found. The proteins designated polypeptide 2 (MW 66 to 70,000) and nucleocapsid protein or NP (MW 61,000) were phosphorylated. The remaining virus-coded proteins were polypeptide 5 (MW 40,000) and the matrix or M protein (MW 37,000). Measles virions also contained a polypeptide (MW 42,000) thought to be actin due to co-migration with this component of uninfected cells. Analysis of in vitro 3 H-acetic anhydride radiolabeled virions confirmed the presence of these seven polypeptides. Acetic anhydride also labeled a protein designated polypeptide 4 (MW 53,000) which was not consistently radiolabeled in vivo, as well as several other minor proteins believed to be cellular in origin. Synthesis of the six virus-specific structural polypeptides was detected in lysates of infected cells by SDS-polyacrylamide slab gel electrophoresis. Virus specificity of polypeptide 4 could not be confirmed due to the similar MW of several cellular polypeptides. Two non-virion, but virus-specified polypeptides, of MW 38,000 and 18,000 were also detected. Synthesis of the virus structural proteins was in the same proportions as the polypeptides found in virions except for under production of polypeptide G and over production of polypeptide 2. (author)

  1. Nanostructured complexes of polyelectrolytes and charged polypeptides

    Czech Academy of Sciences Publication Activity Database

    Müller, M.; Ouyang, W.; Bohatá, Karolína; Kessler, B.

    2010-01-01

    Roč. 12, Sp. Iss. 9 (2010), B519-B528 ISSN 1438-1656. [Sino-German Symposium on Advanced Biomedical Nanostructures /1./. Jena, 26.10.2009-30.10.2009] Institutional research plan: CEZ:AV0Z40500505 Keywords : situ ATR-FTIR * alpha-helical polypeptides * multilayer films Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.746, year: 2010

  2. Natural polypeptide scaffolds: beta-sheets, beta-turns, and beta-hairpins.

    Science.gov (United States)

    Rotondi, Kenneth S; Gierasch, Lila M

    2006-01-01

    This paper provides an introduction to fundamental conformational states of polypeptides in the beta-region of phi,psi space, in which the backbone is extended near to its maximal length, and to more complex architectures in which extended segments are linked by turns and loops. There are several variants on these conformations, and they comprise versatile scaffolds for presentation of side chains and backbone amides for molecular recognition and designed catalysts. In addition, the geometry of these fundamental folds can be readily mimicked in peptidomimetics. Copyright 2005 Wiley Periodicals, Inc.

  3. [New drug developments of snake venom polypeptides and progress].

    Science.gov (United States)

    Fu, Sihai; Feng, Mei; Xiong, Yan

    2017-11-28

    The value of snake venom polypeptides in clinical application has drawn extensive attention, and the development of snake polypeptides into new drugs with anti-tumor, anti-inflammatory, antithrombotic, analgesic or antihypertensive properties has become the recent research hotspot. With the rapid development of molecular biology and biotechnology, the mechanisms of snake venom polypeptides are also gradually clarified. Numerous studies have demonstrated that snake venom polypeptides exert their pharmacological effects by regulating ion channels, cell proliferation, apoptosis, intracellular signaling pathway, and expression of cytokine as well as binding to relevant active sites or receptors.

  4. Holoprosencephaly Variant

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2003-01-01

    Full Text Available The clinical manifestations in 15 patients (6 boys and 9 girls with middle interhemispheric variant (MIH of holoprosencephaly (HPE were compared with classic subtypes (alobar, semilobar, and lobar of HPE in a multicenter study at Stanford University School of Medicine and Lucile Packard Children’s Hospital; Children’s Hospital of Philadelphia; University of California at San Francisco; Texas Scottish Rite Hospital, Dallas; and Kennedy Krieger Institute, Baltimore, MD.

  5. Measles virus-specified polypeptides in infected cells

    International Nuclear Information System (INIS)

    Vainionpaepae, R.

    1979-01-01

    The synthesis of wild-type measles virus-specified polypeptides in Vero cells in pulse-chase experiments, in cells with synchronized protein synthesis by high salt concentration, and in the presence of proteolytic enzyme inhibitors was analyzed by polyacrylamide slab-gel electrophoresis. Six major (L, G, 2, NP, 5 and M) structural polypeptides were identified in infected cells. The results of pulse-chase experiments suggested that most of the structural polypeptides were synthesized at their final length. Polypeptide M was found to be sensitive to trypsin. In TLCK-treated cells its molecular weight was about 1000-2000 daltons higher than in untreated cells. A minor virus-specific polypeptide with a molecular weight of about 23,000 was found as a very faint and diffuse band. In addition, three nonstructural polypeptides with molecular weights of 65,000, 38,000 and 18,000 were also detected. The experiments with proteolytic enzyme inhibitors and with synchronized protein synthesis suggested that the polypeptide with a molecular weight of 65,000 might be a precursor of the structural polypeptide 5. (author)

  6. Caffeine-water-polypeptide interaction in aqueous solution

    Science.gov (United States)

    Ghabi, Habib; Dhahbi, Mahmoud

    1999-04-01

    The interaction of caffeine monomer with the synthetic polypeptides polyasparagine (pAg) and polyaspartic acid (pAsp) was studied by UV spectrophotometry. The results show that different types of interactions are possible depending on the nature of polypeptide. The form of the complex was discussed.

  7. Chirality-selected phase behaviour in ionic polypeptide complexes

    Science.gov (United States)

    Perry, Sarah L.; Leon, Lorraine; Hoffmann, Kyle Q.; Kade, Matthew J.; Priftis, Dimitrios; Black, Katie A.; Wong, Derek; Klein, Ryan A.; Pierce, Charles F.; Margossian, Khatcher O.; Whitmer, Jonathan K.; Qin, Jian; de Pablo, Juan J.; Tirrell, Matthew

    2015-01-01

    Polyelectrolyte complexes present new opportunities for self-assembled soft matter. Factors determining whether the phase of the complex is solid or liquid remain unclear. Ionic polypeptides enable examination of the effects of stereochemistry on complex formation. Here we demonstrate that chirality determines the state of polyelectrolyte complexes, formed from mixing dilute solutions of oppositely charged polypeptides, via a combination of electrostatic and hydrogen-bonding interactions. Fluid complexes occur when at least one of the polypeptides in the mixture is racemic, which disrupts backbone hydrogen-bonding networks. Pairs of purely chiral polypeptides, of any sense, form compact, fibrillar solids with a β-sheet structure. Analogous behaviour occurs in micelles formed from polypeptide block copolymers with polyethylene oxide, where assembly into aggregates with either solid or fluid cores, and eventually into ordered phases at high concentrations, is possible. Chirality is an exploitable tool for manipulating material properties in polyelectrolyte complexation. PMID:25586861

  8. Fibrillar dimer formation of islet amyloid polypeptides

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, Chi-cheng [Univ. of Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States); de Pablo, Juan J. [Univ. of Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-05-08

    Amyloid deposits of human islet amyloid polypeptide (hIAPP), a 37-residue hormone co-produced with insulin, have been implicated in the development of type 2 diabetes. Residues 20 – 29 of hIAPP have been proposed to constitute the amyloidogenic core for the aggregation process, yet the segment is mostly unstructured in the mature fibril, according to solid-state NMR data. Here we use molecular simulations combined with bias-exchange metadynamics to characterize the conformational free energies of hIAPP fibrillar dimer and its derivative, pramlintide. We show that residues 20 – 29 are involved in an intermediate that exhibits transient β-sheets, consistent with recent experimental and simulation results. By comparing the aggregation of hIAPP and pramlintide, we illustrate the effects of proline residues on inhibition of the dimerization of IAPP. The mechanistic insights presented here could be useful for development of therapeutic inhibitors of hIAPP amyloid formation.

  9. Tissue polypeptide antigen activity in cerebrospinal fluid

    DEFF Research Database (Denmark)

    Bach, F; Söletormos, Georg; Dombernowsky, P

    1991-01-01

    Tissue polypeptide antigen (TPpA) in the cerebrospinal fluid (CSF) was measured in 59 consecutive breast cancer patients with suspected central nervous system (CNS) metastases. Subsequently, we determined that 13 patients had parenchymal brain metastases, 10 had leptomeningeal carcinomatosis......, and 36 had no CNS involvement. The concentration of TPpA, which is a nonspecific marker for cell proliferation, was significantly higher in patients with CNS metastases than in those without it (P less than .0001; Mann-Whitney test). A tentative cutoff value for CNS metastases was set at 95 U/L TPp...... metastases, no correlation was found between TPpA activity in corresponding CSF and blood samples (correlation coefficient, Spearman's rho = .4; P greater than .1). In three patients treated for leptomeningeal carcinomatosis, the measurements of CSF TPpA showed correlation between the presence of tumor cells...

  10. Smart systems related to polypeptide sequences

    Directory of Open Access Journals (Sweden)

    Lourdes Franco

    2016-03-01

    Full Text Available Increasing interest for the application of polypeptide-based smart systems in the biomedical field has developed due to the advantages given by the peptidic sequence. This is due to characteristics of these systems, which include: biocompatibility, potential control of degradation, capability to provide a rich repertoire of biologically specific interactions, feasibility to self-assemble, possibility to combine different functionalities, and capability to give an environmentally responsive behavior. Recently, applications concerning the development of these systems are receiving greater attention since a targeted and programmable release of drugs (e.g. anti-cancer agents can be achieved. Block copolymers are discussed due to their capability to render differently assembled architectures. Hybrid systems based on silica nanoparticles are also discussed. In both cases, the selected systems must be able to undergo fast changes in properties like solubility, shape, and dissociation or swelling capabilities. This review is structured in different chapters which explain the most recent advances on smart systems depending on the stimuli to which they are sensitive. Amphiphilic block copolymers based on polyanionic or polycationic peptides are, for example, typically employed for obtaining pH-responsive systems. Elastin-like polypeptides are usually used as thermoresponsive polymers, but performance can be increased by using techniques which utilize layer-by-layer electrostatic self-assembly. This approach offers a great potential to create multilayered systems, including nanocapsules, with different functionality. Recent strategies developed to get redox-, magnetic-, ultrasound-, enzyme-, light- and electric-responsive systems are extensively discussed. Finally, some indications concerning the possibilities of multi-responsive systems are discussed.

  11. Target organs for avian pancreatic polypeptide

    International Nuclear Information System (INIS)

    Kimmel, J.R.; Pollock, H.G.

    1981-01-01

    The problem of the physiological function of pancreatic polypeptide (PP) has been approached by attempting to identify target organs. Avian PP (aPP) labeled with 125I at either the C-terminus (aPP-C) or the N-terminus (aPP-N) was injected into fasted chickens and allowed to circulate for 3-120 min. At the end of the equilibration period, the anesthetized bird was perfused first with saline, then with Buoin's solution. Samples of fixed tissue from various organs were collected, weighed, and counted. Control experiments consisted of coinjection of unlabeled aPP to compete for receptors. The rate of disappearance of aPP-N from plasma was greater than that of aPP-C. Binding of aPP-N by spleen, duodenum, ileum, pancreas, and bone marrow was markedly reduced by coinjection of unlabeled aPP. A similar but less marked reduction in binding was found in liver and proventriculus. aPP-C gave less conclusive results. The maximal competitive effect of unlabeled PP could be achieved in most cases with 30 microgram unlabeled aPP. It is concluded that pancreas, duodenum, ileum, spleen, and bone marrow, and probably liver and proventriculus, are target organs for aPP in the chicken and that the C-terminal region of aPP is involved in receptor binding

  12. Fibrillar dimer formation of islet amyloid polypeptides

    Directory of Open Access Journals (Sweden)

    Chi-cheng Chiu

    2015-09-01

    Full Text Available Amyloid deposits of human islet amyloid polypeptide (hIAPP, a 37-residue hormone co-produced with insulin, have been implicated in the development of type 2 diabetes. Residues 20 – 29 of hIAPP have been proposed to constitute the amyloidogenic core for the aggregation process, yet the segment is mostly unstructured in the mature fibril, according to solid-state NMR data. Here we use molecular simulations combined with bias-exchange metadynamics to characterize the conformational free energies of hIAPP fibrillar dimer and its derivative, pramlintide. We show that residues 20 – 29 are involved in an intermediate that exhibits transient β-sheets, consistent with recent experimental and simulation results. By comparing the aggregation of hIAPP and pramlintide, we illustrate the effects of proline residues on inhibition of the dimerization of IAPP. The mechanistic insights presented here could be useful for development of therapeutic inhibitors of hIAPP amyloid formation.

  13. Tunable drug loading and release from polypeptide multilayer nanofilms

    Science.gov (United States)

    Jiang, Bingbing; Li, Bingyun

    2009-01-01

    Polypeptide multilayer nanofilms were prepared using electrostatic layer-by-layer self-assembly nanotechnology. Small charged drug molecules (eg, cefazolin, gentamicin, and methylene blue) were loaded in polypeptide multilayer nanofilms. Their loading and release were found to be pH-dependent and could also be controlled by changing the number of film layers and drug incubation time, and applying heat-treatment after film formation. Antibioticloaded polypeptide multilayer nanofilms showed controllable antibacterial properties against Staphylococcus aureus. The developed biodegradable polypeptide multilayer nanofilms are capable of loading both positively- and negatively-charged drug molecules and promise to serve as drug delivery systems on biomedical devices for preventing biomedical device-associated infection, which is a significant clinical complication for both civilian and military patients. PMID:19421369

  14. Aqueous cholesteric liquid crystals using uncharged rodlike polypeptides. Polypeptide vesicles by conformation-specific assembly. Ordered chiral macroporous hybrid silica-polypeptide composites

    Science.gov (United States)

    Bellomo, Enrico Giuseppe

    2005-07-01

    Aqueous cholesteric liquid crystals using uncharged rodlike polypeptides . The aqueous, lyotropic liquid-crystalline phase behavior of an alpha helical polypeptide, has been studied using optical microscopy and X-ray scattering. Solutions of optically pure polypeptide were found to form cholesteric liquid crystals at volume fractions that decreased with increasing average chain length. At very high volume fractions, the formation of a hexagonal mesophase was observed. The pitch of the cholesteric phase could be varied by a mixture of enantiomeric samples, where the pitch increased as the mixture approached equimolar. The cholesteric phases could be untwisted, using either magnetic field or shear flow, into nematic phases, which relaxed into cholesterics upon removal of field or shear. We have found that the phase diagram of this polypeptide in aqueous solution parallels that of poly(gamma-benzyl glutamate) in organic solvents, thus providing a useful system for liquid-crystal applications requiring water as solvent. Polypeptide vesicles by conformation-specific assembly. We have found that block copolymers composed of polypeptide segments provide significant advantages in controlling both the function and supramolecular structure of bioinspired self-assemblies. Incorporation of the stable chain conformations found in proteins into block copolymers was found to provide an additional element of control, beyond amphiphilicity and composition that defines self-assembled architecture. The abundance of functionality present in amino acids, and the ease by which they can be incorporated into these materials, also provides a powerful mechanism to impart block copolypeptides with function. This combination of structure and function work synergistically to enable significant advantages in the preparation of therapeutic agents as well as provide insight into design of self-assemblies beginning to approach the complexity of natural structures such as virus capsids. Ordered

  15. Ring-Opening Polymerization of N-Carboxyanhydrides for Preparation of Polypeptides and Polypeptide-Based Hybrid Materials with Various Molecular Architectures

    KAUST Repository

    Pahovnik, David; Hadjichristidis, Nikolaos

    2015-01-01

    Different synthetic approaches utilizing ring-opening polymerization of N-carboxyanhydrides for preparation of polypeptide and polypeptide-based hybrid materials with various molecular architectures are described. An overview of polymerization

  16. Polypeptide profiles of human oocytes and preimplantation embryos.

    Science.gov (United States)

    Capmany, G; Bolton, V N

    1993-11-01

    The polypeptides that direct fertilization and early development until activation of the embryonic genome occurs, at the 4-8 cell stage in the human, are exclusively maternal in origin, and are either synthesized during oogenesis or translated later from maternal mRNA. Using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and silver stain, we have visualized and compared the polypeptides present in different populations of human oocytes and cleavage stage embryos obtained after superovulation and insemination in vitro. Two polypeptide patterns were resolved, differing in the region of mol. wt 69 kDa. The distribution of these patterns showed no correlation with the ability of individual oocytes to achieve fertilization and develop normally to the 8-cell stage.

  17. Conformations of islet amyloid polypeptide monomers in a membrane environment: implications for fibril formation.

    Directory of Open Access Journals (Sweden)

    Mojie Duan

    Full Text Available The amyloid fibrils formed by islet amyloid polypeptide (IAPP are associated with type II diabetes. One of the proposed mechanisms of the toxicity of IAPP is that it causes membrane damage. The fatal mutation of S20G human IAPP was reported to lead to early onset of type II diabetes and high tendency of amyloid formation in vitro. Characterizing the structural features of the S20G mutant in its monomeric state is experimentally difficult because of its unusually fast aggregation rate. Computational work complements experimental studies. We performed a series of molecular dynamics simulations of the monomeric state of human variants in the membrane. Our simulations are validated by extensive comparisons with experimental data. We find that a helical disruption at His18 is common to both human variants. An L-shaped motif of S20G mutant is observed in one of the conformational families. This motif that bends at His18 resembles the overall topology of IAPP fibrils. The conformational preorganization into the fibril-like topology provides a possible explanation for the fast aggregation rate of S20G IAPP.

  18. Polypeptides having beta-glucosidase activity and polynucleotides encoding the same

    Science.gov (United States)

    Brown, Kimberly; Harris, Paul

    2013-12-17

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  19. Vasoactive intestinal polypeptide and other preprovasoactive intestinal polypeptide-derived peptides in the female and male genital tract: localization, biosynthesis, and functional and clinical significance

    DEFF Research Database (Denmark)

    Ottesen, B; Fahrenkrug, J

    1995-01-01

    Vasoactive intestinal polypeptide, a neuropeptide with wide distribution in the central and peripheral nervous system, has a broad spectrum of biologic actions. The demonstration of vasoactive intestinal polypeptide containing nerve fibers within the female and male genital tract 17 years ago...... indicated a putative role for this peptide in the local nervous control of reproductive functions. The genes encoding the preprovasoactive intestinal polypeptide precursor molecule and the vasoactive intestinal polypeptide receptor have been identified. The gene expression has been studied by the use...... in the genital tracts (i.e., blood flow and nonvascular smooth muscle relaxation). In the ovary vasoactive intestinal polypeptide seems to play an important role as regulator and/or modulator of folliculogenesis and steroidogenesis. In the male genital tract vasoactive intestinal polypeptide seems to participate...

  20. CDKL5 variants

    Science.gov (United States)

    Kalscheuer, Vera M.; Hennig, Friederike; Leonard, Helen; Downs, Jenny; Clarke, Angus; Benke, Tim A.; Armstrong, Judith; Pineda, Mercedes; Bailey, Mark E.S.; Cobb, Stuart R.

    2017-01-01

    Objective: To provide new insights into the interpretation of genetic variants in a rare neurologic disorder, CDKL5 deficiency, in the contexts of population sequencing data and an updated characterization of the CDKL5 gene. Methods: We analyzed all known potentially pathogenic CDKL5 variants by combining data from large-scale population sequencing studies with CDKL5 variants from new and all available clinical cohorts and combined this with computational methods to predict pathogenicity. Results: The study has identified several variants that can be reclassified as benign or likely benign. With the addition of novel CDKL5 variants, we confirm that pathogenic missense variants cluster in the catalytic domain of CDKL5 and reclassify a purported missense variant as having a splicing consequence. We provide further evidence that missense variants in the final 3 exons are likely to be benign and not important to disease pathology. We also describe benign splicing and nonsense variants within these exons, suggesting that isoform hCDKL5_5 is likely to have little or no neurologic significance. We also use the available data to make a preliminary estimate of minimum incidence of CDKL5 deficiency. Conclusions: These findings have implications for genetic diagnosis, providing evidence for the reclassification of specific variants previously thought to result in CDKL5 deficiency. Together, these analyses support the view that the predominant brain isoform in humans (hCDKL5_1) is crucial for normal neurodevelopment and that the catalytic domain is the primary functional domain. PMID:29264392

  1. Organic anion transporting polypeptide 1B transporters modulate hydroxyurea pharmacokinetics

    OpenAIRE

    Walker, Aisha L.; Lancaster, Cynthia S.; Finkelstein, David; Ware, Russell E.; Sparreboom, Alex

    2013-01-01

    Hydroxyurea is currently the only FDA-approved drug that ameliorates the pathophysiology of sickle cell anemia. Unfortunately, substantial interpatient variability in the pharmacokinetics (PK) of hydroxyurea may result in variation of the drug's efficacy. However, little is known about mechanisms that modulate hydroxyurea PK. Recent in vitro studies identifying hydroxyurea as a substrate for organic anion transporting polypeptide (OATP1B) transporters prompted the current investigation assess...

  2. Functional Modification of Thioether Groups in Peptides, Polypeptides, and Proteins

    OpenAIRE

    Deming, TJ

    2017-01-01

    Recent developments in the modification of methionine and other thioether-containing residues in peptides, polypeptides, and proteins are reviewed. Properties and potential applications of the resulting functionalized products are also discussed. While much of this work is focused on natural Met residues, modifications at other side-chain residues have also emerged as new thioether-containing amino acids have been incorporated into peptidic materials. Functional modification of thioether-cont...

  3. Generation of polypeptide-templated gold nanoparticles using ionizing radiation.

    Science.gov (United States)

    Walker, Candace Rae; Pushpavanam, Karthik; Nair, Divya Geetha; Potta, Thrimoorthy; Sutiyoso, Caesario; Kodibagkar, Vikram D; Sapareto, Stephen; Chang, John; Rege, Kaushal

    2013-08-13

    Ionizing radiation, including γ rays and X-rays, are high-energy electromagnetic radiation with diverse applications in nuclear energy, astrophysics, and medicine. In this work, we describe the use of ionizing radiation and cysteine-containing elastin-like polypeptides (C(n)ELPs, where n = 2 or 12 cysteines in the polypeptide sequence) for the generation of gold nanoparticles. In the presence of C(n)ELPs, ionizing radiation doses higher than 175 Gy resulted in the formation of maroon-colored gold nanoparticle dispersions, with maximal absorbance at 520 nm, from colorless metal salts. Visible color changes were not observed in any of the control systems, indicating that ionizing radiation, gold salt solution, and C(n)ELPs were all required for nanoparticle formation. The hydrodynamic diameters of nanoparticles, determined using dynamic light scattering, were in the range of 80-150 nm, while TEM imaging indicated the formation of gold cores 10-20 nm in diameter. Interestingly, C2ELPs formed 1-2 nm diameter gold nanoparticles in the absence of radiation. Our results describe a facile method of nanoparticle formation in which nanoparticle size can be tailored based on radiation dose and C(n)ELP type. Further improvements in these polypeptide-based systems can lead to colorimetric detection of ionizing radiation in a variety of applications.

  4. Cotranslational structure acquisition of nascent polypeptides monitored by NMR spectroscopy.

    Science.gov (United States)

    Eichmann, Cédric; Preissler, Steffen; Riek, Roland; Deuerling, Elke

    2010-05-18

    The folding of proteins in living cells may start during their synthesis when the polypeptides emerge gradually at the ribosomal exit tunnel. However, our current understanding of cotranslational folding processes at the atomic level is limited. We employed NMR spectroscopy to monitor the conformation of the SH3 domain from alpha-spectrin at sequential stages of elongation via in vivo ribosome-arrested (15)N,(13)C-labeled nascent polypeptides. These nascent chains exposed either the entire SH3 domain or C-terminally truncated segments thereof, thus providing snapshots of the translation process. We show that nascent SH3 polypeptides remain unstructured during elongation but fold into a compact, native-like beta-sheet assembly when the entire sequence information is available. Moreover, the ribosome neither imposes major conformational constraints nor significantly interacts with exposed unfolded nascent SH3 domain moieties. Our data provide evidence for a domainwise folding of the SH3 domain on ribosomes without significant population of folding intermediates. The domain follows a thermodynamically favorable pathway in which sequential folding units are stabilized, thus avoiding kinetic traps during the process of cotranslational folding.

  5. The influence of the side-chain sequence on the structure-activity correlations of immunomodulatory branched polypeptides. Synthesis and conformational analysis of new model polypeptides.

    Science.gov (United States)

    Mezö, G; Hudecz, F; Kajtár, J; Szókán, G; Szekerke, M

    1989-10-01

    New branched polypeptides were synthesized for a detailed study of the influence of the side-chain structure on the conformation and biological properties. The first subset of polypeptides were prepared by coupling of tetrapeptides to poly[L-Lys]. These polymers contain either DL-Ala3-X [poly[Lys-(X-DL-Ala3)n

  6. Proteolytic processing of poliovirus polypeptides: antibodies to polypeptide P3-7c inhibit cleavage at glutamine-glycine pairs

    International Nuclear Information System (INIS)

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

    1982-01-01

    Proteolytic processing of poliovirus polypeptides was examined by the addition of antibodies directed against the viral proteins P3-7c and P2-X to a cell-free translation extract prepared from infected HeLa cells. Antisera to P3-7c specifically inhibited in vitro processing at Gln-Gly pairs. Partial amino acid sequence analysis revealed a second Tyr-Gly pair that is utilized in protein processing. Neither Tyr-Gly cleavage is affected by antibody to P3-7C. Anti-P3-7c antibodies react not only with P3-7c but also with P3-6a and P3-2, two viral polypeptides NH 2 -coterminal with P3-7c. Preimmune and anti-P2-X antibodies had no effect on the processing of poliovirus proteins in vitro. The authors conclude that the activity responsible for processing poliovirus polypeptides at Gln-Gly pairs resides in the primary structure of P3-7c and not in P2-X

  7. Variants of cellobiohydrolases

    Energy Technology Data Exchange (ETDEWEB)

    Bott, Richard R.; Foukaraki, Maria; Hommes, Ronaldus Wilhelmus; Kaper, Thijs; Kelemen, Bradley R.; Kralj, Slavko; Nikolaev, Igor; Sandgren, Mats; Van Lieshout, Johannes Franciscus Thomas; Van Stigt Thans, Sander

    2018-04-10

    Disclosed are a number of homologs and variants of Hypocrea jecorina Ce17A (formerly Trichoderma reesei cellobiohydrolase I or CBH1), nucleic acids encoding the same and methods for producing the same. The homologs and variant cellulases have the amino acid sequence of a glycosyl hydrolase of family 7A wherein one or more amino acid residues are substituted and/or deleted.

  8. Amino acid substitutions in inherited albumin variants from Amerindian and Japanese populations

    International Nuclear Information System (INIS)

    Takahashi, N.; Takahashi, Y.; Isobe, T.; Putnam, F.W.; Fujita, M.; Satoh, C.; Neel, J.V.

    1987-01-01

    The authors report an effort to determine the basis for the altered migration of seven inherited albumin variants detected by one-dimensional electrophoresis in population surveys involving tribal Amerindians and Japanese children. An amino acid substitution has thus far been determined for four of the variants. The randomness in the albumin polypeptide of these and the other sixteen independently ascertained amino acid substitutions of albumin and proalbumin thus far established was analyzed; the clustering of eight of these at two positions in the six-amino acid propeptide sequence seems noteworthy. By comparison with other proteins studied by electrophoresis, albumin exhibits average variability. It is a paradox that individuals who, for genetic reasons, lack albumin exhibit no obvious ill effects; yet, electrophoretic variants of albumin are no more numerous than are variants of proteins, the absence of which results in severe disease

  9. Basal serum pancreatic polypeptide is dependent on age and gender in an adult population

    DEFF Research Database (Denmark)

    Brimnes Damholt, M; Rasmussen, B K; Hilsted, L

    1997-01-01

    This study is the first epidemiologically based study of basal levels of serum pancreatic polypeptide (s-PP). The basal level of serum PP has become a field of interest mainly due to the role of PP as an endocrine tumour marker, and as a marker of pancreatic neuroendocrine function after pancreas...... a monospecific radioimmunoassay. Fasting serum pancreatic polypeptide depended on age and gender. The results demonstrated that fasting pancreatic polypeptide levels increase exponentially with age. Fitted separately for each sex, basal serum pancreatic polypeptide was found to increase by approximately 3% per...... reports on the fasting levels of serum pancreatic polypeptide are most likely due to lack of adjustment for age and gender. Thus, variation due to age and gender should be considered in evaluating fasting levels of serum pancreatic polypeptide. Whether similar considerations are important when evaluating...

  10. Biochemical map of polypeptides specified by foot-and-mouth disease virus.

    OpenAIRE

    Grubman, M J; Robertson, B H; Morgan, D O; Moore, D M; Dowbenko, D

    1984-01-01

    Pulse-chase labeling of foot-and-mouth disease virus-infected bovine kidney cells revealed stable and unstable viral-specific polypeptides. To identify precursor-product relationships among these polypeptides, antisera against a number of structural and nonstructural viral-specific polypeptides were used. Cell-free translations programmed with foot-and-mouth disease virion RNA or foot-and-mouth disease virus-infected bovine kidney cell lysates, which were shown to contain almost identical pol...

  11. Primary structure, gene organization and polypeptide expression of poliovirus RNA

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, N. (State Univ. of New York, Stony Brook); Semler, B.L.; Rothberg, P.G.

    1981-06-18

    The primary structure of the poliovirus genome has been determined. The RNA molecule is 7433 nucleotides long, polyadenylated at the 3' terminus, and covalently linked to a small protein (VPg) at the 5' terminus. An open reading frame of 2207 consecutive triplets spans over 89% of the nucleotide sequence and codes for the viral polyprotein NCVPOO. Twelve viral polypeptides have been mapped by amino acid sequence analysis and were found to be proteolytic cleavage products of the polyprotein, cleavages occurring predominantly at Gln-Gly pairs.

  12. Reaction mechanisms in the radiolysis of peptides, polypeptides and proteins

    Energy Technology Data Exchange (ETDEWEB)

    Garrison, W.M.

    1985-01-01

    The purpose of this review is to bring together and to correlate the wide variety of experimental studies that provide information on the reaction products and reaction mechanisms involved in the radiolysis of peptides, polypeptides and proteins (including chromosomal proteins) in both aqueous and solid-state systems. The comparative radiation chemistry of these systems is developed in terms of specific reactions of the peptide main-chain and the aliphatic, aromatic-unsaturated and sulfur-containing side-chains. Information obtained with the various experimental techniques of product analysis, competition kinetics, spin-trapping, pulse radiolysis and ESR spectroscopy is included. 147 refs.

  13. Reaction mechanisms in the radiolysis of peptides, polypeptides and proteins

    International Nuclear Information System (INIS)

    Garrison, W.M.

    1985-01-01

    The purpose of this review is to bring together and to correlate the wide variety of experimental studies that provide information on the reaction products and reaction mechanisms involved in the radiolysis of peptides, polypeptides and proteins (including chromosomal proteins) in both aqueous and solid-state systems. The comparative radiation chemistry of these systems is developed in terms of specific reactions of the peptide main-chain and the aliphatic, aromatic-unsaturated and sulfur-containing side-chains. Information obtained with the various experimental techniques of product analysis, competition kinetics, spin-trapping, pulse radiolysis and ESR spectroscopy is included. 147 refs

  14. NMR study of the cooperative behavior of thermotropic model polypeptides

    Czech Academy of Sciences Publication Activity Database

    Kurková, Dana; Kříž, Jaroslav; Rodríguez-Cabello, J. C.; Arias, F. J.

    2007-01-01

    Roč. 56, č. 2 (2007), s. 186-194 ISSN 0959-8103 R&D Projects: GA AV ČR IAA400500604 Grant - others:Spanish Ministry of Science and Culture(ES) A002/02; MAT2000-1764-C02; MAT2001-1853-C02-01; MAT2003- Institutional research plan: CEZ:AV0Z40500505 Keywords : thermotropic polymers * cooperativity * synthetic polypeptides Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.557, year: 2007

  15. Well-defined (co)polypeptides bearing pendant alkyne groups

    KAUST Repository

    Zhao, Wei

    2016-03-18

    A novel metal-free strategy, using hydrogen-bonding catalytic ring opening polymerization of acetylene-functionalized N-carboxy anhydrites of α-amino acids, was developed for the synthesis of well-defined polypeptides bearing pendant alkyne groups. This method provides an efficient way to synthesize novel alkyne-functionalized homopolypeptides (A) and copolypeptides, such as AB diblock (B: non-functionalized), ABA triblock and star-AB diblock, as well as linear and star random copolypeptides, precursors of a plethora complex macromolecular architectures by click chemistry.

  16. Functional Modification of Thioether Groups in Peptides, Polypeptides, and Proteins.

    Science.gov (United States)

    Deming, Timothy J

    2017-03-15

    Recent developments in the modification of methionine and other thioether-containing residues in peptides, polypeptides, and proteins are reviewed. Properties and potential applications of the resulting functionalized products are also discussed. While much of this work is focused on natural Met residues, modifications at other side-chain residues have also emerged as new thioether-containing amino acids have been incorporated into peptidic materials. Functional modification of thioether-containing amino acids has many advantages and is a complementary methodology to the widely utilized methods for modification at cysteine residues.

  17. Well-defined (co)polypeptides bearing pendant alkyne groups

    KAUST Repository

    Zhao, Wei; Gnanou, Yves; Hadjichristidis, Nikolaos

    2016-01-01

    A novel metal-free strategy, using hydrogen-bonding catalytic ring opening polymerization of acetylene-functionalized N-carboxy anhydrites of α-amino acids, was developed for the synthesis of well-defined polypeptides bearing pendant alkyne groups. This method provides an efficient way to synthesize novel alkyne-functionalized homopolypeptides (A) and copolypeptides, such as AB diblock (B: non-functionalized), ABA triblock and star-AB diblock, as well as linear and star random copolypeptides, precursors of a plethora complex macromolecular architectures by click chemistry.

  18. A PYY Q62P variant linked to human obesity

    Energy Technology Data Exchange (ETDEWEB)

    Ahituv, Nadav; Kavaslar, Nihan; Schackwitz, Wendy; Ustaszewska,Anna; Collier, John Michael; Hebert, Sybil; Doelle, Heather; Dent,Robert; Pennacchio, Len A.; McPherson, Ruth

    2005-06-27

    Members of the pancreatic polypeptide family and the irreceptors have been implicated in the control of food intake in rodents and humans. To investigate whether nucleotide changes in these candidate genes result in abnormal weight in humans, we sequenced the coding exons and splice sites of seven family members (NPY, PYY, PPY, NPY1R, NPY2R, NPY4R, and NPY5R) in a large cohort of extremely obese (n=379) and lean (n=378) individuals. In total we found eleven rare non-synonymous variants, four of which exhibited familial segregation, NPY1R L53P and PPY P63L with leanness and NPY2R D42G and PYY Q62P with obesity. Functional analysis of the obese variants revealed NPY2R D42G to have reduced cell surface expression, while previous cell culture based studies indicated variant PYY Q62P to have altered receptor binding selectivity and we show that it fails to reduce food intake through mouse peptide injection experiments. These results support that rare non-synonymous variants within these genes can alter susceptibility to human body mass index extremes.

  19. Migraine Variants in Children

    Science.gov (United States)

    ... Headaches in Children FAQ Migraine Variants In Children Children Get Migraines Too! Learn More Migraine Information Find Help Doctors & Resources Get Connected Join the Conversation Follow Us on Social Media Company About News Resources Privacy Policy Contact Phone: ...

  20. CDNA encoding a polypeptide including a hevein sequence

    Science.gov (United States)

    Raikhel, Natasha V.; Broekaert, Willem F.; Chua, Nam-Hai; Kush, Anil

    1995-03-21

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  1. cDNA encoding a polypeptide including a hevein sequence

    Energy Technology Data Exchange (ETDEWEB)

    Raikhel, N.V.; Broekaert, W.F.; Chua, N.H.; Kush, A.

    2000-07-04

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74--79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  2. Light Scattering Characterization of Elastin-Like Polypeptide Trimer Micelles

    Science.gov (United States)

    Tsuper, Ilona; Terrano, Daniel; Maraschky, Adam; Holland, Nolan; Streletzky, Kiril

    The elastin-like polypeptides (ELP) nanoparticles are composed of three-armed star polypeptides connected by a negatively charged foldon. Each of the three arms extending from the foldon domain includes 20 repeats of the (GVGVP) amino acid sequence. The ELP polymer chains are soluble at room temperature and become insoluble at the transition temperature (close to 50 ° C), forming micelles. The size and shape of the micelle are dependent on the temperature and the pH of the solution, and on the concentration of the phosphate buffered saline (PBS). The depolarized dynamic light scattering (DDLS) was employed to study the structure and dynamics of micelles at 62 ° C. The solution was maintained at an approximate pH level of 7.3 - 7.5, while varying PBS concentration. At low salt concentrations (60 mM) displayed an apparent elongation of the micelles evident by a significant VH signal, along with a surge in the apparent Rh. A model of micelle growth (and potential elongation) with increase in salt concentration is considered.

  3. cDNA encoding a polypeptide including a hevein sequence

    Energy Technology Data Exchange (ETDEWEB)

    Raikhel, N.V.; Broekaert, W.F.; Chua, N.H.; Kush, A.

    1999-05-04

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74--79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli. 12 figs.

  4. cDNA encoding a polypeptide including a hevein sequence

    Energy Technology Data Exchange (ETDEWEB)

    Raikhel, Natasha V. (Okemos, MI); Broekaert, Willem F. (Dilbeek, BE); Chua, Nam-Hai (Scarsdale, NY); Kush, Anil (New York, NY)

    1999-05-04

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  5. cDNA encoding a polypeptide including a hevein sequence

    Energy Technology Data Exchange (ETDEWEB)

    Raikhel, N.V.; Broekaert, W.F.; Chua, N.H.; Kush, A.

    1995-03-21

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1,018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74--79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli. 11 figures.

  6. Polypeptide synthesis in alphavirus-infected aedes albopictus cells during the establishment of persistent infection

    International Nuclear Information System (INIS)

    Richardson, M.A.; Boulton, R.W.; Raghow, R.S.; Dalgarno, L.

    1980-01-01

    Polypeptide synthesis was examined in mosquito cells during the establishment of a persistent infection with two alphaviruses, Ross River virus (RRV) and Semliki Forest virus (SFV), and in vertebrate cells cytopathically-infected with the same viruses. In Aedes albopictus cells, RRV reached peak titres at 34-48 hours p.i. At 12 hours 85 per cent of cells assayed as infected by infective centre assay; by 48 hours when persistence was established, virus production was reduced and <5 per cent of cells assayed as infected. There was not shutdown of host polypeptide synthesis during infection. Viral polypeptide synthesis was maximal between 10 and 24 hours p.i. The major viral polypeptides labelled were nucleocapsid protein and envelope protein(s).The precursor polypeptide p95 which was prominent in infected BHK cells was not detected in mosquito cells. Similar results were obtained on SFV infection. During the establishment of persistence there was a coordinate decline in the synthesis of RRV polypeptides, reaching undetectable levels by 72 hours p.i. Subculturing persistently-infected cells led to a small increase in viral polypeptide synthesis and virus titre. In contrast, during RRV growth in BHK cells host protein synthesis was severely inhibited and by 9-11 hours p.i. virus-specific polypeptide synthesis represented more than 90 per cent of total protein synthetic activity. (author)

  7. Ring-Opening Polymerization of N-Carboxyanhydrides for Preparation of Polypeptides and Polypeptide-Based Hybrid Materials with Various Molecular Architectures

    KAUST Repository

    Pahovnik, David

    2015-09-01

    Different synthetic approaches utilizing ring-opening polymerization of N-carboxyanhydrides for preparation of polypeptide and polypeptide-based hybrid materials with various molecular architectures are described. An overview of polymerization mechanisms using conventional (various amines) as well as some recently developed initiators (hexamethyldisilazane, N-heterocyclic persistent carbenes, etc.) is presented, and their benefits and drawbacks for preparation of polypeptides with well-defined chain lengths and chain-end functionality are discussed. Recent examples from literature are used to illustrate different possibilities for synthesis of pure polypeptide materials with different molecular architectures bearing various functional groups, which are introduced either by modification of amino acids, before they are transformed into corresponding Ncarboxyanhydrides, or by post-polymerization modifications using protective groups and/or orthogonal functional groups. Different approaches for preparation of polypeptide-based hybrid materials are discussed as well using examples from recent literature. Syntheses of simple block copolymers or copolymers with more complex molecular architectures (graft and star copolymers) as well as modifications of nanoparticles and other surfaces with polypeptides are described.

  8. Investigation of the pathophysiological mechanisms of migraine attacks induced by pituitary adenylate cyclase-activating polypeptide-38

    DEFF Research Database (Denmark)

    Amin, Faisal Mohammad; Hougaard, Anders; Schytz, Henrik W

    2014-01-01

    Pituitary adenylate cyclase-activating polypeptide-38 (PACAP38) and vasoactive intestinal polypeptide are structurally and functionally closely related but show differences in migraine-inducing properties. Mechanisms responsible for the difference in migraine induction are unknown. Here, for the ...

  9. NMR and rotational angles in solution conformation of polypeptides

    Science.gov (United States)

    Bystrov, V. F.

    1985-01-01

    Professor San-Ichiro Mizushima and Professor Yonezo Morino's classical contributions provided unique means and firm basis for understanding of conformational states and internal rotation in polypeptide molecules. Now the NMR spectroscopy is the best choice to study molecular conformation, mechanism of action and structure-functional relationships of peptide and proteins in solution under conditions approaching those of their physiological environments. Crucial details of spatial structure and interactions of these molecules in solution are revealed by using proton-proton and carbon-proton vicinal coupling constants, proton nuclear Overhauser effect and spectral perturbation techniques. The results of NMR conformational analysis are presented for valinomycin "bracelet", gramicidin A double helices, honey-bee neurotoxin apamin, scorpion insectotoxins and snake neurotoxins of long and short types.

  10. A radioimmunoassay of gastric inhibitory polypeptide in human plasma

    International Nuclear Information System (INIS)

    Sarson, D.L.; Bryant, M.G.; Bloom, S.R.

    1980-01-01

    A sensitive radioimmunoassay for the measurement of human gastric inhibitory polypeptide (GIP), using pure porcine GIP, has been developed. Cross-reactivity of the antiserum with all available mammalian gut peptide preparations was negligible with the exception of glucagon when it was approximately 1%. Two major molecular forms of GIP were detectable in plasma and tissue extracts, one of large molecular size and the other corresponding to the elution coefficient of pure porcine standard. Concentrations of GIP in plasma from 50 normal subjects after overnight fasting were 9+-1.0(S.E.M.) pmol/1 rising to a peak of 34+-2.8 pmol/1 following the ingestion of a small mixed test meal. Ingestion of glucose or fat resulted in a similar rise of plasma GIP, whereas no change was observed after the ingestion of protein. (author)

  11. Gastric inhibitory polypeptide does not inhibit gastric emptying in humans

    DEFF Research Database (Denmark)

    Meier, Juris J; Goetze, Oliver; Anstipp, Jens

    2004-01-01

    ) = 0.15, P = 0.15 for intact GIP; r(2) = 0.21, P = 0.086 for total GIP). We conclude that gastric emptying does not appear to be influenced by GIP. The secretion of GIP after meal ingestion is not suppressed by its exogenous administration. The lack of effect of GIP on gastric emptying underlines......The insulinotropic gut hormone gastric inhibitory polypeptide (GIP) has been demonstrated to inhibit gastric acid secretion and was proposed to possess "enterogastrone" activity. GIP effects on gastric emptying have not yet been studied. Fifteen healthy male volunteers (23.9 +/- 3.3 yr, body mass....... Gastric emptying was calculated from the (13)CO(2) exhalation rates in breath samples collected over 360 min. Venous blood was drawn in 30-min intervals for the determination of glucose, insulin, C-peptide, and GIP (total and intact). Statistical calculations were made by use of repeated-measures ANOVA...

  12. Vasoactive intestinal polypeptide (VIP) in the pig pancreas

    DEFF Research Database (Denmark)

    Poulsen, Steen Seier

    1984-01-01

    Vasoactive intestinal polypeptide (VIP) in the pig pancreas is localized to nerves, many of which travel along the pancreatic ducts. VIP stimulates pancreatic fluid and bicarbonate secretion like secretin. Electrical vagal stimulation in the pig causes an atropine-resistant profuse secretion...... of bicarbonate-rich pancreatic juice. In an isolated perfused preparation of the pig pancreas with intact vagal nerve supply, electrical vagal stimulation caused an atropine-resistant release of VIP, which accurately parallelled the exocrine secretion of juice and bicarbonate. Perfusion of the pancreas...... with a potent VIP-antiserum inhibited the effect of vagal stimulation on the exocrine secretion. It is concluded, that VIP is responsible for (at least part of) the neurally controlled fluid and bicarbonate secretion from the pig pancreas....

  13. Gastric inhibitory polypeptide receptor: association analyses for obesity of several polymorphisms in large study groups

    Directory of Open Access Journals (Sweden)

    Rief Winfried

    2009-03-01

    Full Text Available Abstract Background Gastric inhibitory polypeptide (GIP is postulated to be involved in type 2 diabetes mellitus and obesity. It exerts its function through its receptor, GIPR. We genotyped three GIPR SNPs (rs8111428, rs2302382 and rs1800437 in German families with at least one obese index patient, two case-control studies and two cross-sectional population-based studies. Methods Genotyping was performed by MALDI-TOF, ARMS-PCR and RFLP. The family-study: 761 German families with at least one extremely obese child or adolescent (n = 1,041 and both parents (n = 1,522. Case-control study: (a German obese children (n = 333 and (b obese adults (n = 987 in comparison to 588 adult lean controls. The two cross-sectional population-based studies: KORA (n = 8,269 and SHIP (n = 4,310. Results We detected over-transmission of the A-allele of rs2302382 in the German families (pTDT-Test = 0.0089. In the combined case-control sample, we estimated an odd ratio of 1.54 (95%CI 1.09;2.19, pCA-Test = 0.014 for homozygotes of the rs2302382 A-allele compared to individuals with no A-allele. A similar trend was found in KORA where the rs2302382 A-allele led to an increase of 0.12 BMI units (p = 0.136. In SHIP, however, the A-allele of rs2302382 was estimated to contribute an average decrease of 0.27 BMI units (p-value = 0.031. Conclusion Our data suggest a potential relevance of GIPR variants for obesity. However, additional studies are warranted in light of the conflicting results obtained in one of the two population-based studies.

  14. Comprehensive behavioral analysis of pituitary adenylate cyclase-activating polypeptide (PACAP knockout mice

    Directory of Open Access Journals (Sweden)

    Satoko eHattori

    2012-10-01

    Full Text Available Pituitary adenylate cyclase-activating polypeptide (PACAP is a neuropeptide acting as a neurotransmitter, neuromodulator, or neurotrophic factor. PACAP is widely expressed throughout the brain and exerts its functions through the PACAP-specific receptor (PAC1. Recent studies reveal that genetic variants of the PACAP and PAC1 genes are associated with mental disorders, and several behavioral abnormalities of PACAP knockout (KO mice are reported. However, an insufficient number of backcrosses was made using PACAP KO mice on the C57BL/6J background due to their postnatal mortality. To elucidate the effects of PACAP on neuropsychiatric function, the PACAP gene was knocked out in F1 hybrid mice (C57BL/6J x 129SvEv for appropriate control of the genetic background. The PACAP KO mice were then subjected to a behavioral test battery. PACAP deficiency had no significant effects on neurological screen. As shown previously, the mice exhibited significantly increased locomotor activity in a novel environment and abnormal anxiety-like behavior, while no obvious differences between genotypes were shown in home cage activity. In contrast to previous reports, the PACAP KO mice showed normal prepulse inhibition and slightly decreased depression-like behavior. Previous study demonstrates that the social interaction in a resident-intruder test was decreased in PACAP KO mice. On the other hand, we showed that PACAP KO mice exhibited increased social interaction in Crawley’s three-chamber social approach test, although PACAP KO had no significant impact on social interaction in a home cage. PACAP KO mice also exhibited mild performance deficit in working memory in an eight-arm radial maze and the T-maze, while they did not show any significant abnormalities in the left-right discrimination task in the T-maze. These results suggest that PACAP has an important role in the regulation of locomotor activity, social behavior, anxiety-like behavior and, potentially

  15. Biosynthesis of human sialophorins and analysis of the polypeptide core

    International Nuclear Information System (INIS)

    Remold-O'Donnell, E.; Kenney, D.; Rosen, F.S.

    1987-01-01

    Biosynthesis was examined of sialophorin (formerly called gpL115) which is altered in the inherited immunodeficiency Wiskott-Aldrich syndrome. Sialophorin is greater than 50% carbohydrate, primarily O-linked units of sialic acid, galactose, and galactosamine. Pulse-labeling with [ 35 S]methionine and chase incubation established that sialophorin is synthesized in CEM lymphoblastoid cells as an Mr 62,000 precursor which is converted within 45 min to mature glycosylated sialophorin, a long-lived molecule. Experiments with tunicamycin and endoglycosidase H demonstrated that sialophorin contains N-linked carbohydrate (approximately two units per molecule) and is therefore an N,O-glycoprotein. Pulse-labeling of tunicamycin-treated CEM cells together with immunoprecipitation provided the means to isolate the [ 35 S]-methionine-labeled polypeptide core of sialophorin and determine its molecular weight (58,000). This datum allowed us to express the previously established composition on a per molecule basis and determine that sialophorin molecules contain approximately 520 amino acid residues and greater than or equal to 100 O-linked carbohydrate units. A recent study showed that various blood cells express sialophorin and that there are two molecular forms: lymphocyte/monocyte sialophorin and platelet/neutrophil sialophorin. Biosynthesis of the two forms was compared by using sialophorin of CEM cells and sialophorin of MOLT-4 cells (another lymphoblastoid line) as models for lymphocyte/monocyte sialophorin and platelet/neutrophil sialophorin, respectively. The time course of biosynthesis and the content of N units were found to be identical for the two sialophorin species. [ 35 S]Methionine-labeled polypeptide cores of CEM sialophorin and MOLT sialophorin were isolated and compared by electrophoresis, isoelectrofocusing, and a newly developed peptide mapping technique

  16. Peptides and polypeptides as scaffolds for optoelectronics and biomaterials applications

    Science.gov (United States)

    Charati, Manoj B.

    Peptides and polypeptides are emerging as a new class of biomaterials due to their unique structural, physiochemical, mechanical, and biological properties. The development of peptide and protein-based biomaterials is driven by the convergence of convenient techniques for peptide/protein engineering and its importance in applications as smart biomaterials. The thesis is divided in two parts; the first part highlights the importance of incorporation of non-natural amino acids into peptides and proteins. In particular, incorporation on p-bromophenylalanine in short alpha-helical peptide templates to control the association of chromophores is discussed. In the second part, design of a multi-component, biocompatible polypeptide with superior elasticity is discussed. Part 1. Novel peptide templates to control association of chromophores. Tailor made peptide and protein materials have many versatile applications, as both conformation and functional group position can be controlled. Such control may have intriguing applications in the development of hybrid materials for electroactive applications. A critical need in fabricating devices from organic semiconducting materials is to achieve control over the conformation and distance between two conjugated chains. Controlling chromophore spacing and orientation with required precision over nanometer length scale poses a greater challenge. Here we propose a peptide based template to control the alignment of the methylstilbene and Oxa-PPV chromophores with desired orientations and spacing. The hybrid peptides were characterized via CD, exciton coupled CD, 1H NMR and photoluminescence experiments. It is observed that slight change in the orientation of molecules has pronounced effect on the photo-physical behavior of the molecules. Characterization of the hybrid peptides via circular dichroism (CD) confirmed the helical character of the designed peptides and indicated that inclusion of non-natural amino acids has significant

  17. Histone variants and lipid metabolism

    NARCIS (Netherlands)

    Borghesan, Michela; Mazzoccoli, Gianluigi; Sheedfar, Fareeba; Oben, Jude; Pazienza, Valerio; Vinciguerra, Manlio

    2014-01-01

    Within nucleosomes, canonical histones package the genome, but they can be opportunely replaced with histone variants. The incorporation of histone variants into the nucleosome is a chief cellular strategy to regulate transcription and cellular metabolism. In pathological terms, cellular steatosis

  18. Moisture absorption and retention properties, and activity in alleviating skin photodamage of collagen polypeptide from marine fish skin.

    Science.gov (United States)

    Hou, Hu; Li, Bafang; Zhang, Zhaohui; Xue, Changhu; Yu, Guangli; Wang, Jingfeng; Bao, Yuming; Bu, Lin; Sun, Jiang; Peng, Zhe; Su, Shiwei

    2012-12-01

    Collagen polypeptides were prepared from cod skin. Moisture absorption and retention properties of collagen polypeptides were determined at different relative humidities. In addition, the protective effects of collagen polypeptide against UV-induced damage to mouse skin were evaluated. Collagen polypeptides had good moisture absorption and retention properties and could alleviate the damage induced by UV radiation. The action mechanisms of collagen polypeptide mainly involved enhancing immunity, reducing the loss of moisture and lipid, promoting anti-oxidative properties, inhibiting the increase of glycosaminoglycans, repairing the endogenous collagen and elastin protein fibres, and maintaining the ratio of type III to type I collagen. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Characterization of an amidated form of pancreatic polypeptide from the daddy sculpin (Cottus scorpius).

    Science.gov (United States)

    Conlon, J M; Schmidt, W E; Gallwitz, B; Falkmer, S; Thim, L

    1986-12-30

    The primary structure of pancreatic polypeptide from the teleostean fish, Cottus scorpius (daddy sculpin) was established as: YPPQPESPGGNASPEDWAKYHAAVRHYVNLITRQRYNH2 The presence of a COOH-terminally alpha-amidated amino acid was established using an HPLC method of general applicability. Although the peptide shows strong homology towards anglerfish pancreatic polypeptide (86%), homology towards porcine peptide YY (PYY) (61%) and porcine neuropeptide Y (NPY) (61%) was greater than towards porcine pancreatic polypeptide (PP) (47%). This result supports suggestions that the gene duplication events which led to PP, NPY and PYY formation took place after the time of divergence of fish and mammals.

  20. The Research on the Impact of Maca Polypeptide on Sport Fatigue.

    Science.gov (United States)

    Miao, Hua

    2015-01-01

    In order to study the effect of maca polypeptide on sport fatigue, this paper selected 40 male mice, and they were randomly divided into group A, B, C and D. group A, B and C were fed food with different concentrations of maca polypeptide, and group D was control group. After two weeks of feeding, measured physiological indexes of mice, including blood glucose, urea nitrogen and creatinine. At last gived the experimental results, as well as the analysis. Experimental results show that maca polypeptide can improve the ability of anti-fatigue mice, and in a certain concentration range, the higher the concentration, the better the resistance to fatigue.

  1. Processes for the production of hydroxycinnamic acids using polypeptides having tyrosine ammonia lyase activity

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention generally relates to the field of biotechnology as it applies to the production of hydroxycinnamic acids using polypeptides having tyrosine ammonia lyase activity. More particularly, the present invention pertains to polypeptides having tyrosine ammonia lyase activity and high...... substrate specificity towards tyrosine, which makes them particularly suitable in the production of p-coumaric acid and other hydroxycinnamic acids. The present invention thus provides processes for the production of p-coumaric acid and other hydroxycinnamic acids employing these polypeptides as well...

  2. Cancer Nano technology Using Elastin-Like Polypeptides

    International Nuclear Information System (INIS)

    Siti Najila Mohd Janib

    2014-01-01

    Despite progress in understanding cancer biology, this knowledge has not translated into comparable advances in the clinic. Two fundamental problems currently stalling the efficient treatment of cancer have been detecting cancer early enough for successful treatment and avoiding excessive toxicity to normal tissues. In view of this, cancer still remains one of the leading causes of mortality worldwide, affecting over 10 million new patients every year. Clearly the development of novel approaches for early detection and treatment of cancer is urgently needed to increase patient survival. Recently, nano technology-based systems have emerged as novel therapeutic modalities for cancer treatment. Tiny man made nanoparticles, much smaller than a virus, are being developed to package, transport, and deliver imaging and therapeutic agents. Co-inclusion of these agents, into nano carriers might be advantageous because they increase solubility of hydrophobic drugs, enhance permeability across physiological barriers, alter drug biodistribution, increase local bioavailability and reduce side effects. Initial findings have been promising and nanoparticles have been shown to deliver therapeutic agents to target cells and effect tumor growth. To this end our lab is investigating a class of biodegradable and biocompatible polymers known as elastin-like polypeptides (ELP). Elastin like polypeptide is a bio polymer derived from the structural motif found in mammalian elastin protein and has a sequence dependent transition temperature that can be used as nano carriers to treat diseases. ELPs are characterized by the pentameric repeat VPGXG, where X can be any amino acid. All functional ELPs undergo inverse phase transition whereby below its transition temperature, they exist in a solubilized form while above its transition temperature they undergo phase separation which leads to their aggregation in solution. This process is reversible. Phase transition can also be triggered by other

  3. Variants of glycoside hydrolases

    Science.gov (United States)

    Teter, Sarah [Davis, CA; Ward, Connie [Hamilton, MT; Cherry, Joel [Davis, CA; Jones, Aubrey [Davis, CA; Harris, Paul [Carnation, WA; Yi, Jung [Sacramento, CA

    2011-04-26

    The present invention relates to variants of a parent glycoside hydrolase, comprising a substitution at one or more positions corresponding to positions 21, 94, 157, 205, 206, 247, 337, 350, 373, 383, 438, 455, 467, and 486 of amino acids 1 to 513 of SEQ ID NO: 2, and optionally further comprising a substitution at one or more positions corresponding to positions 8, 22, 41, 49, 57, 113, 193, 196, 226, 227, 246, 251, 255, 259, 301, 356, 371, 411, and 462 of amino acids 1 to 513 of SEQ ID NO: 2 a substitution at one or more positions corresponding to positions 8, 22, 41, 49, 57, 113, 193, 196, 226, 227, 246, 251, 255, 259, 301, 356, 371, 411, and 462 of amino acids 1 to 513 of SEQ ID NO: 2, wherein the variants have glycoside hydrolase activity. The present invention also relates to nucleotide sequences encoding the variant glycoside hydrolases and to nucleic acid constructs, vectors, and host cells comprising the nucleotide sequences.

  4. Stability and function of interdomain linker variants of glucoamylase 1 from Aspergillus niger.

    Science.gov (United States)

    Sauer, J; Christensen, T; Frandsen, T P; Mirgorodskaya, E; McGuire, K A; Driguez, H; Roepstorff, P; Sigurskjold, B W; Svensson, B

    2001-08-07

    Several variants of glucoamylase 1 (GA1) from Aspergillus niger were created in which the highly O-glycosylated peptide (aa 468--508) connecting the (alpha/alpha)(6)-barrel catalytic domain and the starch binding domain was substituted at the gene level by equivalent segments of glucoamylases from Hormoconis resinae, Humicola grisea, and Rhizopus oryzae encoding 5, 19, and 36 amino acid residues. Variants were constructed in which the H. resinae linker was elongated by proline-rich sequences as this linker itself apparently was too short to allow formation of the corresponding protein variant. Size and isoelectric point of GA1 variants reflected differences in linker length, posttranslational modification, and net charge. While calculated polypeptide chain molecular masses for wild-type GA1, a nonnatural proline-rich linker variant, H. grisea, and R. oryzae linker variants were 65,784, 63,777, 63,912, and 65,614 Da, respectively, MALDI-TOF-MS gave values of 82,042, 73,800, 73,413, and 90,793 Da, respectively, where the latter value could partly be explained by an N-glycosylation site introduced near the linker C-terminus. The k(cat) and K(m) for hydrolysis of maltooligodextrins and soluble starch, and the rate of hydrolysis of barley starch granules were essentially the same for the variants as for wild-type GA1. beta-Cyclodextrin, acarbose, and two heterobidentate inhibitors were found by isothermal titration calorimetry to bind to the catalytic and starch binding domains of the linker variants, indicating that the function of the active site and the starch binding site was maintained. The stability of GA1 linker variants toward GdnHCl and heat, however, was reduced compared to wild-type.

  5. Molecular Dynamics Simulation of Cholera Toxin A-1 Polypeptide

    Directory of Open Access Journals (Sweden)

    Badshah Syed Lal

    2016-01-01

    Full Text Available A molecular dynamics (MD simulation study of the enzymatic portion of cholera toxin; cholera toxin A-1 polypeptide (CTA1 was performed at 283, 310 and 323 K. From total energy analysis it was observed that this toxin is stable thermodynamically and these outcomes were likewise confirmed by root mean square deviations (RMSD investigations. The Cα root mean square fluctuation (RMSF examinations revealed that there are a number of residues inside CTA1, which can be used as target for designing and synthesizing inhibitory drugs, in order to inactivate cholera toxin inside the human body. The fluctuations in the radius of gyration and hydrogen bonding in CTA1 proved that protein unfolding and refolding were normal routine phenomena in its structure at all temperatures. Solvent accessible surface area study identified the hydrophilic nature of the CTA1, and due to this property it can be a potential biological weapon. The structural identification (STRIDE algorithm for proteins was successfully used to determine the partially disordered secondary structure of CTA1. On account of this partially disordered secondary structure, it can easily deceive the proteolytic enzymes of the endoplasmic reticulum of host cells.

  6. Vasoactive intestinal polypeptide (VIP) innervation of the human eyelid glands.

    Science.gov (United States)

    Seifert, P; Spitznas, M

    1999-06-01

    This study was conducted to obtain morphological proof of innervating nerve fibres in the glands of the human eyelid (accessory lacrimal glands of Wolfring, meibomian glands, goblet cells, glands of Zeis, glands of Moll, sweat glands, glands of lanugo hair follicles) and identification of the secretomotorically active neuropeptide vasoactive intestinal polypeptide (VIP) as a common transmitter. Epoxy-embedded ultrathin sections of tissue samples from human eyelids were studied using electron microscopy. Paraffin sections fixed in Bouin-Hollande solution were immunostained with rabbit antiserum against VIP. With the electron microscope we were able to identify nerves in the glandular stroma of all the glands examined with the exception of goblet cells. Intraepithelial single axons were only seen in the parenchyma of Wolfring glands. The morphological findings corresponded with the immunological finding of VIP-positive, nerve-like structures in the same locations, with the exception of lanugo hair follicle glands, and goblet cells. Our findings indicate that the glands of the eyelids and main lacrimal gland represent a functional unit with VIP as a possible common stimulating factor. Copyright 1999 Academic Press.

  7. Aspects of structural landscape of human islet amyloid polypeptide

    Energy Technology Data Exchange (ETDEWEB)

    He, Jianfeng, E-mail: hjf@bit.edu.cn; Dai, Jin, E-mail: daijing491@gmail.com [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Li, Jing, E-mail: jinglichina@139.com [Institute of Biopharmaceutical Research, Yangtze River Pharmaceutical Group Beijing Haiyan Pharmaceutical Co., Ltd, Beijing 102206 (China); Peng, Xubiao, E-mail: xubiaopeng@gmail.com [Department of Physics and Astronomy, Uppsala University, P.O. Box 803, S-75108 Uppsala (Sweden); Niemi, Antti J., E-mail: Antti.Niemi@physics.uu.se [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Department of Physics and Astronomy, Uppsala University, P.O. Box 803, S-75108 Uppsala (Sweden); Laboratoire de Mathematiques et Physique Theorique CNRS UMR 6083, Fédération Denis Poisson, Université de Tours, Parc de Grandmont, F37200 Tours (France)

    2015-01-28

    The human islet amyloid polypeptide (hIAPP) co-operates with insulin to maintain glycemic balance. It also constitutes the amyloid plaques that aggregate in the pancreas of type-II diabetic patients. We have performed extensive in silico investigations to analyse the structural landscape of monomeric hIAPP, which is presumed to be intrinsically disordered. For this, we construct from first principles a highly predictive energy function that describes a monomeric hIAPP observed in a nuclear magnetic resonance experiment, as a local energy minimum. We subject our theoretical model of hIAPP to repeated heating and cooling simulations, back and forth between a high temperature regime where the conformation resembles a random walker and a low temperature limit where no thermal motions prevail. We find that the final low temperature conformations display a high level of degeneracy, in a manner which is fully in line with the presumed intrinsically disordered character of hIAPP. In particular, we identify an isolated family of α-helical conformations that might cause the transition to amyloidosis, by nucleation.

  8. Bovine pancreatic polypeptide as an antagonist of muscarinic cholinergic receptors

    International Nuclear Information System (INIS)

    Pan, G.Z.; Lu, L.; Qian, J.; Xue, B.G.

    1987-01-01

    In dispersed acini from rat pancreas, it was found that bovine pancreatic polypeptide (BPP) and its C-fragment hexapeptide amide (PP-6), at concentrations of 0.1 and 30 μM, respectively, could significantly inhibit amylase secretion stimulated by carbachol, and this inhibition by BPP was dose dependent. 45 Ca outflux induced by carbachol was also inhibited by BPP or PP-6, but they had no effect on cholecystokinin octapeptide- (CCK-8) or A23187-stimulated 45 Ca outflux. BPP was also capable of displacing the specific binding of [ 3 H]-quinuclidinyl benzilate to its receptors, and it possessed a higher affinity (K/sub i/35nM) than carbachol (K/sub i/ 1.8 μM) in binding with M-receptors. It is concluded from this study that BPP acts as an antagonist of muscarinic cholinergic receptors in rat pancreatic acini. In addition, BPP inhibited the potentiation of amylase secretion caused by the combination of carbachol plus secretin or vasoactive intestinal peptide. This may be a possible explanation of the inhibitory effect of BPP on secretin-induced pancreatic enzyme secretion shown in vivo, since pancreatic enzyme secretion stimulated by secretin under experimental conditions may be the result of potentiation of enzyme release produced by the peptide in combination with a cholinergic stimulant

  9. Intestinal mucosa is a target tissue for pancreatic polypeptide

    International Nuclear Information System (INIS)

    Gilbert, W.R.; Kramer, J.L.; Frank, B.H.; Gingerich, R.L.

    1986-01-01

    Studies were carried out to identify mammalian tissues capable of specifically binding mammalian pancreatic polypeptide (PP). Bovine PP (bPP) radiolabeled with 125 I was purified by HPLC to yield [ 125 I]iodo-(Tyr-27) bPP. The label was injected into three pairs of fasted littermate dogs and allowed to circulate for 5 min. One of the dogs was a control which received an excess of unlabeled porcine PP to provide competition for receptor binding. Unbound bPP was removed by perfusion with Krebs-Ringer bicarbonate and the tissue fixed in situ with Karnovsky's fixative. Tissue samples from various organs were removed, weighed, and counted. The entire gastrointestinal tract demonstrated high levels of 125 I after injection of the labeled peptide. The duodenum, jejunum, ileum, and colon were the only tissues to exhibit specific binding of bPP. These tissues (mucosal and muscle layers) from experimental animals exhibited 31-76% higher binding than the corresponding tissues from the control animals. Sections of the gastrointestinal tract were scraped to separate the mucosal layer from the underlying muscle layer. The mucosal layer of the duodenum, jejunum, and ileum exhibited 145-162% increases in binding compared to the control animals. The muscle layer of these tissues demonstrated no significant increase. These findings demonstrate that mucosal layer of the small intestine is a target tissue for mammalian PP

  10. Star-Shaped Polypeptides: Synthesis and Opportunities for Delivery of Therapeutics.

    Science.gov (United States)

    Byrne, Mark; Murphy, Robert; Kapetanakis, Antonios; Ramsey, Joanne; Cryan, Sally-Ann; Heise, Andreas

    2015-09-17

    Significant advances in the synthesis of polypeptides by N-carboxyanhydride (NCA) polymerisation over the last decade have enabled the design of advanced polypeptide architectures such as star-shaped polypeptides. These materials combine the functionality offered by amino acids with the flexibility of creating stable nanoparticles with adjustable cargo space for therapeutic delivery. This review highlights recent advances in the synthesis of star polypeptides by NCA polymerisation followed by a critical review of the applications of this class of polymer in the delivery of therapeutic agents. This includes examples of traditional small-molecule drugs as well as the emerging class of biologics such as genetic therapeutics (gene delivery). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Simultaneous Polymerization and Polypeptide Particle Production via Reactive Spray-Drying.

    Science.gov (United States)

    Glavas, Lidija; Odelius, Karin; Albertsson, Ann-Christine

    2016-09-12

    A method for producing polypeptide particles via in situ polymerization of N-carboxyanhydrides during spray-drying has been developed. This method was enabled by the development of a fast and robust synthetic pathway to polypeptides using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as an initiator for the ring-opening polymerization of N-carboxyanhydrides. The polymerizations finished within 5 s and proved to be very tolerant toward impurities such as amino acid salts and water. The formed particles were prepared by mixing the monomer, N-carboxyanhydride of l-glutamic acid benzyl ester (NCAGlu) and the initiator (DBU) during the atomization process in the spray-dryer and were spherical with a size of ∼1 μm. This method combines two steps; making it a straightforward process that facilitates the production of polypeptide particles. Hence, it furthers the use of spray-drying and polypeptide particles in the pharmaceutical industry.

  12. Accelerated evolution of the pituitary adenylate cyclase-activating polypeptide precursor gene during human origin

    DEFF Research Database (Denmark)

    Wang, Yin-Qiu; Qian, Ya-Ping; Yang, Su

    2005-01-01

    Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide abundantly expressed in the central nervous system and involved in regulating neurogenesis and neuronal signal transduction. The amino acid sequence of PACAP is extremely conserved across vertebrate species, indicating a...

  13. Induction of protein body formation in plant leaves by elastin-like polypeptide fusions

    Directory of Open Access Journals (Sweden)

    Joensuu Jussi J

    2009-08-01

    Full Text Available Abstract Background Elastin-like polypeptides are synthetic biopolymers composed of a repeating pentapeptide 'VPGXG' sequence that are valuable for the simple non-chromatographic purification of recombinant proteins. In addition, elastin-like polypeptide fusions have been shown to enhance the accumulation of a range of different recombinant proteins in plants, thus addressing the major limitation of plant-based expression systems, which is a low production yield. This study's main objectives were to determine the general utility of elastin-like polypeptide protein fusions in various intracellular compartments and to elucidate elastin-like polypeptide's mechanism of action for increasing recombinant protein accumulation in the endoplasmic reticulum of plants. Results The effect of elastin-like polypeptide fusions on the accumulation of green fluorescent protein targeted to the cytoplasm, chloroplasts, apoplast, and endoplasmic reticulum was evaluated. The endoplasmic reticulum was the only intracellular compartment in which an elastin-like polypeptide tag was shown to significantly enhance recombinant protein accumulation. Interestingly, endoplasmic reticulum-targeted elastin-like polypeptide fusions induced the formation of a novel type of protein body, which may be responsible for elastin-like polypeptide's positive effect on recombinant protein accumulation by excluding the heterologous protein from normal physiological turnover. Although expressed in the leaves of plants, these novel protein bodies appeared similar in size and morphology to the prolamin-based protein bodies naturally found in plant seeds. The elastin-like polypeptide-induced protein bodies were highly mobile organelles, exhibiting various dynamic patterns of movement throughout the cells, which were dependent on intact actin microfilaments and a functional actomyosin motility system. Conclusion An endoplasmic reticulum-targeted elastin-like polypeptide fusion approach

  14. Loss of UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase 3 and reduced O-glycosylation in colon carcinoma cells selected for hepatic metastasis

    DEFF Research Database (Denmark)

    Kato, Kentaro; Takeuchi, Hideyuki; Kanoh, Akira

    2010-01-01

    O-glycosylation of mucin is initiated by the attachment of N-acetyl-D-galactosamine (GalNAc) to serine or threonine residues in mucin core polypeptides by UDPGalNAc:polypeptide N-acetylgalactosaminyltransferases (ppGalNAc-Ts). It is not well understood how GalNAc attachment is regulated by multiple...... ppGalNAc-Ts in each cell. In the present study, the expression levels of murine ppGalNAc-Ts (mGalNAc-Ts), T1, T2, T3, T4, T6, and T7 were compared between mouse colon carcinoma colon 38 cells and variant SL4 cells, selected for their metastatic potentials, by using the competitive RT-PCR method....... The expression levels of mGalNAc-T1, T2, and T7 were slightly higher in the SL4 cells than in the colon 38 cells, whereas the expression level of mGalNAc-T3 in the SL4 cells was 1.5% of that in the colon 38 cells. Products of enzymatic incorporations of GalNAc residues into FITCPTTTPITTTTK peptide by the use...

  15. A de novo designed 11 kDa polypeptide: model for amyloidogenic intrinsically disordered proteins.

    Science.gov (United States)

    Topilina, Natalya I; Ermolenkov, Vladimir V; Sikirzhytski, Vitali; Higashiya, Seiichiro; Lednev, Igor K; Welch, John T

    2010-07-01

    A de novo polypeptide GH(6)[(GA)(3)GY(GA)(3)GE](8)GAH(6) (YE8) has a significant number of identical weakly interacting beta-strands with the turns and termini functionalized by charged amino acids to control polypeptide folding and aggregation. YE8 exists in a soluble, disordered form at neutral pH but is responsive to changes in pH and ionic strength. The evolution of YE8 secondary structure has been successfully quantified during all stages of polypeptide fibrillation by deep UV resonance Raman (DUVRR) spectroscopy combined with other morphological, structural, spectral, and tinctorial characterization. The YE8 folding kinetics at pH 3.5 are strongly dependent on polypeptide concentration with a lag phase that can be eliminated by seeding with a solution of folded fibrillar YE8. The lag phase of polypeptide folding is concentration dependent leading to the conclusion that beta-sheet folding of the 11-kDa amyloidogenic polypeptide is completely aggregation driven.

  16. Accurate genotyping across variant classes and lengths using variant graphs

    DEFF Research Database (Denmark)

    Sibbesen, Jonas Andreas; Maretty, Lasse; Jensen, Jacob Malte

    2018-01-01

    of read k-mers to a graph representation of the reference and variants to efficiently perform unbiased, probabilistic genotyping across the variation spectrum. We demonstrate that BayesTyper generally provides superior variant sensitivity and genotyping accuracy relative to existing methods when used...... collecting a set of candidate variants across discovery methods, individuals and databases, and then realigning the reads to the variants and reference simultaneously. However, this realignment problem has proved computationally difficult. Here, we present a new method (BayesTyper) that uses exact alignment...... to integrate variants across discovery approaches and individuals. Finally, we demonstrate that including a ‘variation-prior’ database containing already known variants significantly improves sensitivity....

  17. Organic anion transporting polypeptide 1B transporters modulate hydroxyurea pharmacokinetics.

    Science.gov (United States)

    Walker, Aisha L; Lancaster, Cynthia S; Finkelstein, David; Ware, Russell E; Sparreboom, Alex

    2013-12-15

    Hydroxyurea is currently the only FDA-approved drug that ameliorates the pathophysiology of sickle cell anemia. Unfortunately, substantial interpatient variability in the pharmacokinetics (PK) of hydroxyurea may result in variation of the drug's efficacy. However, little is known about mechanisms that modulate hydroxyurea PK. Recent in vitro studies identifying hydroxyurea as a substrate for organic anion transporting polypeptide (OATP1B) transporters prompted the current investigation assessing the role of OATP1B transporters in modulating hydroxyurea PK. Using wild-type and Oatp1b knockout (Oatp1b(-/-)) mice, hydroxyurea PK was analyzed in vivo by measuring [(14)C]hydroxyurea distribution in plasma, kidney, liver, urine, or the exhaled (14)CO2 metabolite. Plasma levels were significantly reduced by 20% in Oatp1b(-/-) mice compared with wild-type (area under the curve of 38.64 or 48.45 μg·h(-1)·ml(-1), respectively) after oral administration, whereas no difference was observed between groups following intravenous administration. Accumulation in the kidney was significantly decreased by twofold in Oatp1b(-/-) mice (356.9 vs. 748.1 pmol/g), which correlated with a significant decrease in urinary excretion. Hydroxyurea accumulation in the liver was also decreased (136.6 vs. 107.3 pmol/g in wild-type or Oatp1b(-/-) mice, respectively) correlating with a decrease in exhaled (14)CO2. These findings illustrate that deficiency of Oatp1b transporters alters the absorption, distribution, and elimination of hydroxyurea thus providing the first in vivo evidence that cell membrane transporters may play a significant role in modulating hydroxyurea PK. Future studies to investigate other transporters and their role in hydroxyurea disposition are warranted for understanding the sources of variation in hydroxyurea's PK.

  18. Quantifying polypeptide conformational space: sensitivity to conformation and ensemble definition.

    Science.gov (United States)

    Sullivan, David C; Lim, Carmay

    2006-08-24

    Quantifying the density of conformations over phase space (the conformational distribution) is needed to model important macromolecular processes such as protein folding. In this work, we quantify the conformational distribution for a simple polypeptide (N-mer polyalanine) using the cumulative distribution function (CDF), which gives the probability that two randomly selected conformations are separated by less than a "conformational" distance and whose inverse gives conformation counts as a function of conformational radius. An important finding is that the conformation counts obtained by the CDF inverse depend critically on the assignment of a conformation's distance span and the ensemble (e.g., unfolded state model): varying ensemble and conformation definition (1 --> 2 A) varies the CDF-based conformation counts for Ala(50) from 10(11) to 10(69). In particular, relatively short molecular dynamics (MD) relaxation of Ala(50)'s random-walk ensemble reduces the number of conformers from 10(55) to 10(14) (using a 1 A root-mean-square-deviation radius conformation definition) pointing to potential disconnections in comparing the results from simplified models of unfolded proteins with those from all-atom MD simulations. Explicit waters are found to roughen the landscape considerably. Under some common conformation definitions, the results herein provide (i) an upper limit to the number of accessible conformations that compose unfolded states of proteins, (ii) the optimal clustering radius/conformation radius for counting conformations for a given energy and solvent model, (iii) a means of comparing various studies, and (iv) an assessment of the applicability of random search in protein folding.

  19. Binary polypeptide system for permanent and oriented protein immobilization

    Directory of Open Access Journals (Sweden)

    Bailes Julian

    2010-05-01

    Full Text Available Abstract Background Many techniques in molecular biology, clinical diagnostics and biotechnology rely on binary affinity tags. The existing tags are based on either small molecules (e.g., biotin/streptavidin or glutathione/GST or peptide tags (FLAG, Myc, HA, Strep-tag and His-tag. Among these, the biotin-streptavidin system is most popular due to the nearly irreversible interaction of biotin with the tetrameric protein, streptavidin. The major drawback of the stable biotin-streptavidin system, however, is that neither of the two tags can be added to a protein of interest via recombinant means (except for the Strep-tag case leading to the requirement for chemical coupling. Results Here we report a new immobilization system which utilizes two monomeric polypeptides which self-assemble to produce non-covalent yet nearly irreversible complex which is stable in strong detergents, chaotropic agents, as well as in acids and alkali. Our system is based on the core region of the tetra-helical bundle known as the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex. This irreversible protein attachment system (IPAS uses either a shortened syntaxin helix and fused SNAP25-synaptobrevin or a fused syntaxin-synaptobrevin and SNAP25 allowing a two-component system suitable for recombinant protein tagging, capture and immobilization. We also show that IPAS is suitable for use with traditional beads and chromatography, planar surfaces and Biacore, gold nanoparticles and for protein-protein interaction in solution. Conclusions IPAS offers an alternative to chemical cross-linking, streptavidin-biotin system and to traditional peptide affinity tags and can be used for a wide range of applications in nanotechnology and molecular sciences.

  20. Variants of Moreau's sweeping process

    International Nuclear Information System (INIS)

    Siddiqi, A.H.; Manchanda, P.

    2001-07-01

    In this paper we prove the existence and uniqueness of two variants of Moreau's sweeping process -u'(t) is an element of Nc (t) (u(t)), where in one variant we replace u(t) by u'(t) in the right-hand side of the inclusion and in the second variant u'(t) and u(t) are respectively replaced by u''(t) and u'(t). (author)

  1. UV cross-linking of polypeptides associated with 3'-terminal exons

    International Nuclear Information System (INIS)

    Stolow, D.T.; Berget, S.M.

    1990-01-01

    Association of nuclear proteins with chimeric vertebrate precursor RNAs containing both polyadenylation signals and an intron was examined by UV cross-linking. One major difference in cross-linking pattern was observed between this chimeric precursor RNA and precursors containing only polyadenylation or splicing signals. The heterogeneous nuclear ribonucleoprotein (hnRNP) polypeptide C cross-linked strongly to sequences downstream of the A addition site in polyadenylation precursor RNA containing only the polyadenylation signal from the simian virus 40 (SV40) late transcription unit. In contrast, the hnRNP C polypeptide cross-linked to chimeric RNA containing the same SV40 late poly(A) cassette very poorly, at a level less than 5% of that observed with the precursor RNA containing just the poly(A) site. Observation that cross-linking of the hnRNP C polypeptide to elements within the SV40 late poly(A) site was altered by the presence of an upstream intron suggests differences in the way nuclear factors associate with poly(A) sites in the presence and absence of an upstream intron. Cross-linking of C polypeptide to chimeric RNA increased with RNAs mutated for splicing or polyadenylation consensus sequences and under reaction conditions (high magnesium) that inhibited polyadenylation. Furthermore, cross-linking of hnRNP C polypeptide to precursors containing just the SV40 late poly(A) site was eliminated in the presence of competing poly(U); polyadenylation, however, was unaffected. Correlation of loss of activity with high levels of hnRNP C polypeptide cross-linking raises questions about the specificity of the interaction between the hnRNP C polypeptide and polyadenylation precursor RNAs in vitro

  2. The mining of toxin-like polypeptides from EST database by single residue distribution analysis.

    Science.gov (United States)

    Kozlov, Sergey; Grishin, Eugene

    2011-01-31

    Novel high throughput sequencing technologies require permanent development of bioinformatics data processing methods. Among them, rapid and reliable identification of encoded proteins plays a pivotal role. To search for particular protein families, the amino acid sequence motifs suitable for selective screening of nucleotide sequence databases may be used. In this work, we suggest a novel method for simplified representation of protein amino acid sequences named Single Residue Distribution Analysis, which is applicable both for homology search and database screening. Using the procedure developed, a search for amino acid sequence motifs in sea anemone polypeptides was performed, and 14 different motifs with broad and low specificity were discriminated. The adequacy of motifs for mining toxin-like sequences was confirmed by their ability to identify 100% toxin-like anemone polypeptides in the reference polypeptide database. The employment of novel motifs for the search of polypeptide toxins in Anemonia viridis EST dataset allowed us to identify 89 putative toxin precursors. The translated and modified ESTs were scanned using a special algorithm. In addition to direct comparison with the motifs developed, the putative signal peptides were predicted and homology with known structures was examined. The suggested method may be used to retrieve structures of interest from the EST databases using simple amino acid sequence motifs as templates. The efficiency of the procedure for directed search of polypeptides is higher than that of most currently used methods. Analysis of 39939 ESTs of sea anemone Anemonia viridis resulted in identification of five protein precursors of earlier described toxins, discovery of 43 novel polypeptide toxins, and prediction of 39 putative polypeptide toxin sequences. In addition, two precursors of novel peptides presumably displaying neuronal function were disclosed.

  3. The mining of toxin-like polypeptides from EST database by single residue distribution analysis

    Directory of Open Access Journals (Sweden)

    Grishin Eugene

    2011-01-01

    Full Text Available Abstract Background Novel high throughput sequencing technologies require permanent development of bioinformatics data processing methods. Among them, rapid and reliable identification of encoded proteins plays a pivotal role. To search for particular protein families, the amino acid sequence motifs suitable for selective screening of nucleotide sequence databases may be used. In this work, we suggest a novel method for simplified representation of protein amino acid sequences named Single Residue Distribution Analysis, which is applicable both for homology search and database screening. Results Using the procedure developed, a search for amino acid sequence motifs in sea anemone polypeptides was performed, and 14 different motifs with broad and low specificity were discriminated. The adequacy of motifs for mining toxin-like sequences was confirmed by their ability to identify 100% toxin-like anemone polypeptides in the reference polypeptide database. The employment of novel motifs for the search of polypeptide toxins in Anemonia viridis EST dataset allowed us to identify 89 putative toxin precursors. The translated and modified ESTs were scanned using a special algorithm. In addition to direct comparison with the motifs developed, the putative signal peptides were predicted and homology with known structures was examined. Conclusions The suggested method may be used to retrieve structures of interest from the EST databases using simple amino acid sequence motifs as templates. The efficiency of the procedure for directed search of polypeptides is higher than that of most currently used methods. Analysis of 39939 ESTs of sea anemone Anemonia viridis resulted in identification of five protein precursors of earlier described toxins, discovery of 43 novel polypeptide toxins, and prediction of 39 putative polypeptide toxin sequences. In addition, two precursors of novel peptides presumably displaying neuronal function were disclosed.

  4. Side-chain-controlled self-assembly of polystyrene-polypeptide miktoarm star copolymers

    KAUST Repository

    Junnila, Susanna

    2012-03-27

    We show how the self-assembly of miktoarm star copolymers can be controlled by modifying the side chains of their polypeptide arms, using A 2B and A 2B 2 type polymer/polypeptide hybrids (macromolecular chimeras). Initially synthesized PS 2PBLL and PS 2PBLL 2 (PS, polystyrene; PBLL, poly(ε-tert-butyloxycarbonyl-l-lysine) ) miktoarms were first deprotected to PS 2PLLHCl and PS 2PLLHCl 2 miktoarms (PLLHCl, poly(l-lysine hydrochloride)) and then complexed ionically with sodium dodecyl sulfonate (DS) to give the supramolecular complexes PS 2PLL(DS) and PS 2(PLL(DS)) 2. The solid-state self-assemblies of these six miktoarm systems were studied by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and small- and wide-angle X-ray scattering (SAXS, WAXS). The side chains of the polypeptide arms were observed to have a large effect on the solubility, polypeptide conformation, and self-assembly of the miktoarms. Three main categories were observed: (i) lamellar self-assemblies at the block copolymer length scale with packed layers of α-helices in PS 2PBLL and PS 2PBLL 2; (ii) charge-clustered polypeptide micelles with less-defined conformations in a nonordered lattice within a PS matrix in PS 2PLLHCl and PS 2PLLHCl 2; (iii) lamellar polypeptide-surfactant self-assemblies with β-sheet conformation in PS 2PLL(DS) and PS 2(PLL(DS)) 2 which dominate over the formation of block copolymer scale structures. Differences between the 3- and 4-arm systems illustrate how packing frustration between the coil-like PS arms and rigid polypeptide conformations can be relieved by the right number of arms, leading to differences in the extent of order. © 2012 American Chemical Society.

  5. Hairy cell leukemia-variant

    International Nuclear Information System (INIS)

    Quadri, Mohammad I.; Al-Sheikh, Iman H.

    2001-01-01

    Hairy cell leukaemia variant is a very rare chronic lymphoproliferative disorder and is closely related to hairy cell leukemia. We hereby describe a case of hairy cell leukaemia variant for the first time in Saudi Arabia. An elderly Saudi man presented with pallor, massive splenomegaly, and moderate hepatomegaly. Hemoglobin was 7.7 g/dl, Platelets were 134 x109/l and white blood count was 140x10 9/l with 97% being abnormal lymphoid cells with cytoplasmic projections. The morphology, cytochemistry, and immunophenotype of the lymphoid cells were classical of hairy cell leukaemia variant. The bone marrow was easily aspirated and findings were consistent with hairy cell leukaemia variant. (author)

  6. Product Variant Master as a Means to Handle Variant Design

    DEFF Research Database (Denmark)

    Hildre, Hans Petter; Mortensen, Niels Henrik; Andreasen, Mogens Myrup

    1996-01-01

    be implemented in the CAD system I-DEAS. A precondition for high degree of computer support is identification of a product variant master from which new variants can be derived. This class platform defines how a product build up fit certain production methods and rules governing determination of modules...

  7. Brachytherapy Using Elastin-Like Polypeptides with (131)I Inhibit Tumor Growth in Rabbits with VX2 Liver Tumor.

    Science.gov (United States)

    Liu, Xinpei; Shen, Yiming; Zhang, Xuqian; Lin, Rui; Jia, Qiang; Chang, Yixiang; Liu, Wenge; Liu, Wentian

    2016-10-01

    Brachytherapy is a targeted type of radiotherapy utilized in the treatment of cancers. Elastin-like polypeptides are a unique class of genetically engineered peptide polymers that have several attractive properties for brachytherapy. To explore the feasibility and application of brachytherapy for VX2 liver tumor using elastin-like polypeptides with (131)I so as to provide reliable experimental evidence for a new promising treatment of liver cancer. Elastin-like polypeptide as carrier was labeled with (131)I using the iodogen method. Ten eligible rabbits with VX2 liver tumor were randomly divided into the treatment group (n = 5) and control group (n = 5). The treatment group received brachytherapy using elastin-like polypeptide with (131)I, and in the control group, elastin-like polypeptide was injected into the VX2 liver tumor as a control. Periodic biochemical and imaging surveillances were required to assess treatment efficacy. The stability of elastin-like polypeptide with (131)I in vitro was maintained at over 96.8 % for 96 h. Biochemistry and imaging indicated brachytherapy using elastin-like polypeptide with (131)I for liver tumor can improve liver function and inhibit tumor growth (P Elastin-like polypeptide can be an ideal carrier of (131)I and have high labeling efficiency, radiochemical purity and stability. Brachytherapy using elastin-like polypeptide with (131)I for liver tumor is a useful therapy that possesses high antitumor efficacy advantages.

  8. Polycondensation of Asparagine-comprising Dipeptides in Aqueous Media-A Simulation of Polypeptide Formation in Primordial Earth Hydrosphere

    Science.gov (United States)

    Munegumi, Toratane; Tanikawa, Naoya

    2017-09-01

    Asparagine and aspartic acid might have mutually transformed in the primordial hydrosphere of the earth, if ammonia and aspartic acid had existed in equilibrium. These amino acids seem to contribute to polypeptides, while the simple amino acids glycine and alanine easily form cyclic dipeptides and do not achieve long peptide chains. Asparagine-comprising dipeptides contribute some kinds of activation forms of dipeptides because these can polymerize faster than asparagine only. The new finding of polypeptide formation suggests a pathway of sequential polypeptides to evolve a diversity of polypeptides.

  9. Polycondensation of Asparagine-comprising Dipeptides in Aqueous Media-A Simulation of Polypeptide Formation in Primordial Earth Hydrosphere.

    Science.gov (United States)

    Munegumi, Toratane; Tanikawa, Naoya

    2017-09-01

    Asparagine and aspartic acid might have mutually transformed in the primordial hydrosphere of the earth, if ammonia and aspartic acid had existed in equilibrium. These amino acids seem to contribute to polypeptides, while the simple amino acids glycine and alanine easily form cyclic dipeptides and do not achieve long peptide chains. Asparagine-comprising dipeptides contribute some kinds of activation forms of dipeptides because these can polymerize faster than asparagine only. The new finding of polypeptide formation suggests a pathway of sequential polypeptides to evolve a diversity of polypeptides.

  10. Avian leukosis virus is a versatile eukaryotic platform for polypeptide display

    International Nuclear Information System (INIS)

    Khare, Pranay D.; Russell, Stephen J.; Federspiel, Mark J.

    2003-01-01

    Display technology refers to methods of generating libraries of modularly coded biomolecules and screening them for particular properties. Retroviruses are good candidates to be a eukaryotic viral platform for the display of polypeptides synthesized in eukaryotic cells. Here we demonstrate that avian leukosis virus (ALV) provides an ideal platform for display of nonviral polyaeptides expressed in a eukaryotic cell substrate. Different sizes of polypeptides were genetically fused to the extreme N-terminus of the ALV envelope glycoprotein in an ALV infectious clone containing an alkaline phosphatase reporter gene. The chimeric envelope glycoproteins were efficiently incorporated into virions and were stably displayed on the surface of the virions through multiple virus replication cycles. The foreign polypeptides did not interfere with the attachment and entry functions of the underlying ALV envelope glycoproteins. The displayed polypeptides were fully functional and could efficiently mediate attachment of the recombinant viruses to their respective cognate receptors. This study demonstrates that ALV is an ideal display platform for the generation and selection of libraries of polypeptides where there is a need for expression, folding, and posttranslational modification in the endoplasmic reticulum of eukaryotic cells

  11. Ultrastructural and biochemical detection of biotin and biotinylated polypeptides in Schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    Santos P.R.P.

    1997-01-01

    Full Text Available Biotinylation is proposed for the identification of surface proteins in Schistosoma mansoni using the streptavidin-HRP conjugate for the detection of labeled polypeptides. However, control samples also showed several endogenous biotinylated polypeptides. In an attempt to determine the possibility of nonspecific binding between the streptavidin-HRP conjugate and polypeptides from S. mansoni, the conjugate was blocked with biotinamidecaproate-N-hydroxysuccinimide ester (BcapNHS before biotin-streptavidin blotting. No bands were detected on the nitrocellulose sheet, demonstrating the specific recognition of biotin by the streptavidin present in the conjugate. Whole cercariae and cercarial bodies and tails showed several endogenous biotinylated polypeptides. The biotin concentration was 13 µg/190,000 cercariae. Adult worms presented less endogenous biotinylated polypeptides than cercariae. These results may be due to changes in the environment from aerobic to anaerobic conditions when cercarial bodies (schistosomula are transformed into adult worms and a decrease in CO2 production may occur. Cercariae, cercarial bodies and adult male worms were examined by transmission electron microscopy employing an avidin-colloidal gold conjugate for the detection of endogenous biotin. Gold particles were distributed mainly on the muscle fibers, but dispersed granules were observed in the tegument, mitochondria and cytosol. The discovery of endogenous biotin in S. mansoni should be investigated in order to clarify the function of this vitamin in the parasite

  12. Congenital deficiency of two polypeptide subunits of the iron-protein fragment of mitochondrial complex I.

    Science.gov (United States)

    Moreadith, R W; Cleeter, M W; Ragan, C I; Batshaw, M L; Lehninger, A L

    1987-02-01

    Recently, we described a patient with severe lactic acidosis due to congenital complex I (NADH-ubiquinone oxidoreductase) deficiency. We now report further enzymatic and immunological characterizations. Both NADH and ferricyanide titrations of complex I activity (measured as NADH-ferricyanide reductase) were distinctly altered in the mitochondria from the patient's tissues. In addition, antisera against complex I immunoprecipitated NADH-ferricyanide reductase from the control but not the patient's mitochondria. However, immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of complex I polypeptides demonstrated that the majority of the 25 polypeptides comprising complex I were present in the affected mitochondria. A more detailed analysis using subunit selective antisera against the main polypeptides of the iron-protein fragments of complex I revealed a selective absence of the 75- and 13-kD polypeptides. These findings suggest that the underlying basis for this patient's disease was a congenital deficiency of at least two polypeptides comprising the iron-protein fragment of complex I, which resulted in the inability to correctly assemble a functional enzyme complex.

  13. Fabrication of genetically engineered polypeptide@quantum dots hybrid nanogels for targeted imaging

    Science.gov (United States)

    Yang, Jie; Yao, Ming-Hao; Zhao, Dong-Hui; Zhang, Xiao-Shuai; Jin, Rui-Mei; Zhao, Yuan-Di; Liu, Bo

    2017-08-01

    Nanogels have been widely used as multifunctional drug delivery carriers because of high water content, biocompatibility, and high loading capability. We designed and biosynthesized two triblock artificial polypeptides PC10A and PC10ARGD as vehicles for encapsulating hydrophobic materials. These polypeptides can form nanogels by self-assembly when the concentration is below 2% ( w/ v). The physical properties of nanogels, including size, surface potential, and targeting domain, are able to be tuned. Hydrophobic materials from molecular size to nano-size can be loaded into the polypeptide nanogels to form hybrid nanogels. Hydrophobic quantum dots CdSe@ZnS below 10 nM were loaded into the polypeptide nanogels by ultrasonic treatment. Encapsulation endows hydrophobic QDs with good tunability of size, water solubility, stability, targeting, and biocompatibility. PC10ARGD nanogels and PC10ARGD@QDs hybrid nanogels showed excellent biocompatibility, which the cellular viabilities of HeLa and MCF-7 cells treated with 1% PC10ARGD nanogels and PC10ARGD@QDs hybrid nanogels contained 20 nM QDs were above 90 and 80%, respectively. PC10ARGD@QDs hybrid nanogels with an arginine-glycine-aspartic acid motif present efficient receptor-mediated endocytosis in α v β 3 overexpressing HeLa cells but not in the control MCF-7 cells as analyzed by confocal microscopy. These results demonstrate that such polypeptide nanogels as nanocarriers are expected to have great potential applications in biomedicine.

  14. Application of Statistical Thermodynamics To Predict the Adsorption Properties of Polypeptides in Reversed-Phase HPLC.

    Science.gov (United States)

    Tarasova, Irina A; Goloborodko, Anton A; Perlova, Tatyana Y; Pridatchenko, Marina L; Gorshkov, Alexander V; Evreinov, Victor V; Ivanov, Alexander R; Gorshkov, Mikhail V

    2015-07-07

    The theory of critical chromatography for biomacromolecules (BioLCCC) describes polypeptide retention in reversed-phase HPLC using the basic principles of statistical thermodynamics. However, whether this theory correctly depicts a variety of empirical observations and laws introduced for peptide chromatography over the last decades remains to be determined. In this study, by comparing theoretical results with experimental data, we demonstrate that the BioLCCC: (1) fits the empirical dependence of the polypeptide retention on the amino acid sequence length with R(2) > 0.99 and allows in silico determination of the linear regression coefficients of the log-length correction in the additive model for arbitrary sequences and lengths and (2) predicts the distribution coefficients of polypeptides with an accuracy from 0.98 to 0.99 R(2). The latter enables direct calculation of the retention factors for given solvent compositions and modeling of the migration dynamics of polypeptides separated under isocratic or gradient conditions. The obtained results demonstrate that the suggested theory correctly relates the main aspects of polypeptide separation in reversed-phase HPLC.

  15. Analysis of urine composition in type Ⅱ diabetic mice after intervention therapy using holothurian polypeptides

    Science.gov (United States)

    Li, Yanyan; Xu, Jiajie; Su, Xiurong

    2017-07-01

    Hydrolysates and peptide fractions (PF) obtained from sea cucumber with commercial enzyme were studied on the hpyerglycemic and renal protective effects on db/db rats using urine metabolomics. Compared with the control group the polypeptides from the two species could significantly reduce the urine glucose and urea. We also tried to address the compositions of highly expressed urinary proteins using a proteomics approach. They were serum albumins, AMBP proteins, negative trypsin, elastase and urinary protein, GAPDH, a receptor of urokinase-type plasminogen activator (uPAR), and Ig kappa chain C region. We used the electronic nose to quickly detect changes in the volatile substances in mice urine after holothurian polypeptides fed, and the results show it can identify the difference between treatment groups with the control group without overlapping. The protein express mechanism of holothurian polypeptides treating diabetes was discussed, and we suggested these two peptides with the hypoglycemic and renal protective activity might be utilized as nutraceuticals.

  16. Comparison between the polypeptide profile of halophilic bacteria and salt tolerant plants.

    Science.gov (United States)

    Muñoz, G; González, C; Flores, P; Prado, B; Campos, V

    1997-12-01

    Changes in the polypeptide profile induced by salt stress in halotolerant and halophilic bacteria, isolated from the Atacama desert (northern Chile), were compared with those in the cotyledons of Prosopis chilensis (Leguminoseae) seedlings, a salt tolerant plant. SDS-PAGE analyses show the presence of four predominant polypeptides, with molecular weights around 78, 70, 60 and 44 kDa respectively, both in bacteria and in cotyledons from P. chilensis seedlings raised under salt stress conditions. Moreover, the 60 and 44 kDa polypeptides seem to be salt responsive, since their concentration increases with increasing NaCl in the growth medium. Our results suggest a common mechanism for salt tolerance in prokaryotes and in eukaryotes.

  17. Effect of oxygen on morphogenesis and polypeptide expression by Mucor racemosus

    International Nuclear Information System (INIS)

    Phillips, G.J.; Borgia, P.T.

    1985-01-01

    The morphology of Mucor racemosus in cultures continuously sparged with nitrogen gas was investigated. When appropriate precautions were taken to prevent oxygen from entering the cultures, the morphology of the cells was uniformly yeastlike irrespective of the N 2 flow rate. When small amounts of oxygen entered the cultures the resulting microaerobic conditions evoked mycelial development. Polypeptides synthesized by aerobic mycelia, microaerobic mycelia, anaerobic yeasts, and yeasts grown in a CO 2 atmosphere were compared by two-dimensional gel electrophoresis. The results indicated that a large number of differences in polypeptide expression exist when microaerobic mycelia or anaerobic yeasts are compared with aerobic mycelia and that these alterations correlate with a change from an oxidative to a fermentative metabolic mode. The authors hypothesize that oxygen regulates the expression of polypeptides involved in both the metabolic mode and in morphogenesis

  18. Synthetic profiles of polypeptides of human oocytes and normal and abnormal preimplantation embryos.

    Science.gov (United States)

    Capmany, G; Bolton, V N

    1999-09-01

    There is considerable variation in the rate of development in vitro of individual preimplantation human embryos. The relationship between the rate of development and patterns of polypeptide synthesis in individual embryos was examined using SDS-PAGE and autoradiography. After incubation in [35S]methionine, 19 polypeptide bands were identified that change between fertilization and the morula stage. Although changes in two of the bands occurred in embryos that were developing normally and in ageing oocytes, and are thus independent of fertilization, the changes identified in the remaining 17 bands occurred only after fertilization. In embryos that were developing abnormally, as assessed by delayed cleavage, cleavage arrest or extensive fragmentation, the alteration in polypeptide synthetic profiles increased with increasing abnormality.

  19. Investigation of Gelatin Polypeptides of Jellyfish (Rhopilema esculentum for Their Antioxidant Activity in vitro

    Directory of Open Access Journals (Sweden)

    Yong-Liang Zhuang

    2010-01-01

    Full Text Available Jellyfish gelatin was hydrolyzed by different proteases to obtain antioxidative polypeptides. The gelatin hydrolysate obtained by progressive hydrolysis using trypsin and Properase E exhibited the highest hydrolysis degree and antioxidant activity. Three series of gelatin polypeptides (SCP1, SCP2 and SCP3 were obtained by ultrafiltrating the gelatin hydrolysate through molecular mass cut-off membranes of 10, 6 and 2 kDa, respectively. Amino acid composition analysis showed that SCP3 had the highest total hydrophobic amino acid content. The in vitro antioxidant tests demonstrated that SCP2 had the strongest hydroxyl radical and hydrogen peroxide scavenging activities and metal chelating ability, while SCP3 showed the highest reducing power, antioxidant activity in linoleic acid emulsion system and superoxide anion radical scavenging activity. The results support the feasibility of jellyfish gelatin as a natural antioxidant polypeptide provider, and enzymatic hydrolysis and ultrafiltration could be potent future processing technologies to utilize the abundant jellyfish resource.

  20. GAWK, a novel human pituitary polypeptide: isolation, immunocytochemical localization and complete amino acid sequence.

    Science.gov (United States)

    Benjannet, S; Leduc, R; Lazure, C; Seidah, N G; Marcinkiewicz, M; Chrétien, M

    1985-01-16

    During the course of reverse-phase high pressure liquid chromatography (RP-HPLC) purification of a postulated big ACTH (1) from human pituitary gland extracts, a highly purified peptide bearing no resemblance to any known polypeptide was isolated. The complete sequence of this 74 amino acid polypeptide, called GAWK, has been determined. Search on a computer data bank on the possible homology to any known protein or fragment, using a mutation data matrix, failed to reveal any homology greater than 30%. An antibody produced against a synthetic fragment allowed us to detect several immunoreactive forms. The antisera also enabled us to localize the polypeptide, by immunocytochemistry, in the anterior lobe of the pituitary gland.

  1. Induction of salivary polypeptides associated with parotid hypertrophy by gallotannins administered topically into the mouse mouth.

    Science.gov (United States)

    Gho, Francesca; Peña-Neira, Alvaro; López-Solís, Remigio O

    2007-02-01

    Isoproterenol-induced salivary polypeptides (IISP), a group of proline-rich proteins synthesized by mouse parotids, have been considered as markers for isoproterenol-induced parotid hypertrophy. Rodents fed diets containing high-tannin cereals (sorghum), also develop parotid hypertrophy. To test whether tannins are directly involved in provoking sialotrophic growth, we studied the effect of intraperitoneal and topical oral administrations of tannic acid (TA) on the induction of IISP polypeptides in endogamic mice (A/Snell). TA was characterized by HPLC chromatography and spectral analysis and shown to be composed solely of gallotannins, a complex family of glucose and gallic acid esters. IISP polypeptides were monitored in saliva by SDS-polyacrylamide gel electrophoresis during 36 h after ending TA stimulation. Single daily intraperitoneal administrations of TA for 3 consecutive days (0.033 mg/g bw/day), at variance of parallel administrations of isoproterenol (0.042 mg/g bw/day) failed to induce IISP polypeptides. However, repeated topical applications of TA into the mouse mouths (1.21 mg/g bw divided into three equal doses given at 4-h intervals within a single day) resulted in unequivocal induction of IISP polypeptides. That response was clearly intensified by increasing the stimulation frequency to eight equivalent doses given at 1.5-h intervals within a single day (corresponding to 3.23 mg/g bw) and even further by repeating this protocol for 3 days. Under these productive schemes of stimulations by TA, electrophoretic fractionation of parotid homogenates showed new polypeptide bands migrating in parallel to salivary IISP. These results suggest that topically administered gallotannins are effective inducers of trophic growth in mouse parotids.

  2. 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.

  3. Phase transition in polypeptides: a step towards the understanding of protein folding

    DEFF Research Database (Denmark)

    Yakubovich, Alexander V.; Solov'yov, Ilia; Solov'yov, Andrey V.

    2006-01-01

    We present a formalism which turns out to be very successful in the description of the polypeptide folding. We consider this process as a first-order phase transition and develop a theory which is free of model parameters and is based solely on fundamental physical principles. It describes...... essential thermodynamical properties of the system such as heat capacity, the phase transition temperature and others from the analysis of the polypeptide potential energy surface calculated within ab initio density functional theory and parameterized by two dihedral angles. This problem is viewed...

  4. The interdomain flexible linker of the polypeptide GalNAc transferases dictates their long-range glycosylation preferences

    DEFF Research Database (Denmark)

    Rivas, Matilde De Las; Lira-Navarrete, Erandi; Daniel, Earnest James Paul

    2017-01-01

    The polypeptide GalNAc-transferases (GalNAc-Ts), that initiate mucin-type O-glycosylation, consist of a catalytic and a lectin domain connected by a flexible linker. In addition to recognizing polypeptide sequence, the GalNAc-Ts exhibit unique long-range N- A nd/or C-terminal prior glycosylation ...

  5. Tuning the conformation of synthetic co-polypeptides of serine and glutamic acid through control over polymer composition

    NARCIS (Netherlands)

    Canning, A.; Pasquazi, A.; Fijten, M.; Rajput, S.; Buttery, L.; Aylott, J.W.; Zelzer, M.

    2016-01-01

    Ring opening polymerization (ROP) of N-carboxy anhydride (NCA) amino acids presents a rapid way to synthesize high molecular weight polypeptides with different amino acid compositions. The compositional and functional versatility of polypeptides make these materials an attractive choice for

  6. Cloning, tissue distribution and effects of fasting on pituitary adenylate cyclase-activating polypeptide in largemouth bass

    Science.gov (United States)

    Li, Shengjie; Han, Linqiang; Bai, Junjie; Ma, Dongmei; Quan, Yingchun; Fan, Jiajia; Jiang, Peng; Yu, Lingyun

    2015-03-01

    Pituitary adenylate cyclase activating polypeptide (PACAP) has a wide range of biological functions. We cloned the full-length cDNAs encoding PACAP and PACAP-related peptide (PRP) from the brain of largemouth bass ( Micropterus salmoides) and used real-time quantitative PCR to detect PRP-PACAP mRNA expression. The PRP-PACAP cDNA has two variants expressed via alternative splicing: a long form, which encodes both PRP and PACAP, and a short form, which encodes only PACAP. Sequence analysis results are consistent with a higher conservation of PACAP than PRP peptide sequences. The expression of PACAP-long and PACAP-short transcripts was highest in the forebrain, followed by the medulla, midbrain, pituitary, stomach, cerebellum, intestine, and kidney; however, these transcripts were either absent or were weakly expressed in the muscle, spleen, gill, heart, fatty tissue, and liver. The level of PACAP-short transcript expression was significantly higher than expression of the long transcript in the forebrain, cerebella, pituitary and intestine, but lower than that of the long transcript in the stomach. PACAP-long and PACAP-short transcripts were first detected at the blastula stage of embryogenesis, and the level of expression increased markedly between the muscular contraction stage and 3 d post hatch (dph). The expression of PACAP-long and PACAP-short transcripts decreased significantly in the brain following 4 d fasting compared with the control diet group. The down-regulation effect was enhanced as fasting continued. Conversely, expression levels increased significantly after 3 d of re-feeding. Our results suggest that PRP-PACAP acts as an important factor in appetite regulation in largemouth bass.

  7. Polymorphisms in the human tropoelastin gene modify in vitro self-assembly and mechanical properties of elastin-like polypeptides.

    Directory of Open Access Journals (Sweden)

    David He

    Full Text Available Elastin is a major structural component of elastic fibres that provide properties of stretch and recoil to tissues such as arteries, lung and skin. Remarkably, after initial deposition of elastin there is normally no subsequent turnover of this protein over the course of a lifetime. Consequently, elastic fibres must be extremely durable, able to withstand, for example in the human thoracic aorta, billions of cycles of stretch and recoil without mechanical failure. Major defects in the elastin gene (ELN are associated with a number of disorders including Supravalvular aortic stenosis (SVAS, Williams-Beuren syndrome (WBS and autosomal dominant cutis laxa (ADCL. Given the low turnover of elastin and the requirement for the long term durability of elastic fibres, we examined the possibility for more subtle polymorphisms in the human elastin gene to impact the assembly and long-term durability of the elastic matrix. Surveys of genetic variation resources identified 118 mutations in human ELN, 17 being non-synonymous. Introduction of two of these variants, G422S and K463R, in elastin-like polypeptides as well as full-length tropoelastin, resulted in changes in both their assembly and mechanical properties. Most notably G422S, which occurs in up to 40% of European populations, was found to enhance some elastomeric properties. These studies reveal that even apparently minor polymorphisms in human ELN can impact the assembly and mechanical properties of the elastic matrix, effects that over the course of a lifetime could result in altered susceptibility to cardiovascular disease.

  8. Pituitary adenylate cyclase activating polypeptide (PACAP signalling exerts chondrogenesis promoting and protecting effects: implication of calcineurin as a downstream target.

    Directory of Open Access Journals (Sweden)

    Tamás Juhász

    Full Text Available Pituitary adenylate cyclase activating polypeptide (PACAP is an important neurotrophic factor influencing differentiation of neuronal elements and exerting protecting role during traumatic injuries or inflammatory processes of the central nervous system. Although increasing evidence is available on its presence and protecting function in various peripheral tissues, little is known about the role of PACAP in formation of skeletal components. To this end, we aimed to map elements of PACAP signalling in developing cartilage under physiological conditions and during oxidative stress. mRNAs of PACAP and its receptors (PAC1,VPAC1, VPAC2 were detectable during differentiation of chicken limb bud-derived chondrogenic cells in micromass cell cultures. Expression of PAC1 protein showed a peak on days of final commitment of chondrogenic cells. Administration of either the PAC1 receptor agonist PACAP 1-38, or PACAP 6-38 that is generally used as a PAC1 antagonist, augmented cartilage formation, stimulated cell proliferation and enhanced PAC1 and Sox9 protein expression. Both variants of PACAP elevated the protein expression and activity of the Ca-calmodulin dependent Ser/Thr protein phosphatase calcineurin. Application of PACAPs failed to rescue cartilage formation when the activity of calcineurin was pharmacologically inhibited with cyclosporine A. Moreover, exogenous PACAPs prevented diminishing of cartilage formation and decrease of calcineurin activity during oxidative stress. As an unexpected phenomenon, PACAP 6-38 elicited similar effects to those of PACAP 1-38, although to a different extent. On the basis of the above results, we propose calcineurin as a downstream target of PACAP signalling in differentiating chondrocytes either in normal or pathophysiological conditions. Our observations imply the therapeutical perspective that PACAP can be applied as a natural agent that may have protecting effect during joint inflammation and/or may promote

  9. Functional polypeptides obtained by living ring opening polymerizations of N-carboxyanhydrides

    NARCIS (Netherlands)

    Habraken, G.J.M.

    2011-01-01

    N-Carboxyanhydride ring opening polymerization (NCA ROP) is a method to prepare polypeptides with a high degree of polymerization in large quantities. The living polymerization technique of NCA ROP gave the opportunity to synthesize many polymer architectures with well-defined blocks and copolymers

  10. The synthesis and characterization of polypeptide-adriamycin conjugates and its complexes with adriamycin. Part I

    NARCIS (Netherlands)

    Heeswijk, W.A.R.; Hoes, C.J.T.; Stoffer, T.; Eenink, M.J.D.; Potman, W.; Feijen, Jan

    1985-01-01

    Poly(α-l-glutamic acid) (PGA) was grafted with amino acid and oligopeptide spacers up to 5 amino acids with the use of N,N'-carbonyldiimidazole and 2,3-dihydro-1,2-benz-isothiazole-3-on-1, 1-dioxide (saccharin) as an additive, and these polypeptides were characterized. The antitumor antibiotic

  11. Gastric inhibitory polypeptide (GIP) dose-dependently stimulates glucagon secretion in healthy human subjects at euglycaemia

    DEFF Research Database (Denmark)

    Meier, J J; Gallwitz, B; Siepmann, N

    2003-01-01

    AIMS/HYPOTHESIS: In the isolated perfused pancreas, gastric inhibitory polypeptide (GIP) has been shown to enhance glucagon secretion at basal glucose concentrations, but in healthy humans no glucagonotropic effect of GIP has yet been reported. Therefore, we studied the effect of GIP on glucagon ...

  12. Molecular cloning and protein structure of a human blood group Rh polypeptide

    International Nuclear Information System (INIS)

    Cherif-Zahar, B.; Bloy, C.; Le Van Kim, C.; Blanchard, D.; Bailly, P.; Hermand, P.; Salmon, C.; Cartron, J.P.; Colin, Y.

    1990-01-01

    cDNA clones encoding a human blood group Rh polypeptide were isolated from a human bone marrow cDNA library by using a polymerase chain reaction-amplified DNA fragment encoding the known common N-terminal region of the Rh proteins. The entire primary structure of the Rh polypeptide has been deduced from the nucleotide sequence of a 1384-base-pair-long cDNA clone. Translation of the open reading frame indicates that the Rh protein is composed of 417 amino acids, including the initiator methionine, which is removed in the mature protein, lacks a cleavable N-terminal sequence, and has no consensus site for potential N-glycosylation. The predicted molecular mass of the protein is 45,500, while that estimated for the Rh protein analyzed in NaDodSO 4 /polyacrylamide gels is in the range of 30,000-32,000. These findings suggest either that the hydrophobic Rh protein behaves abnormally on NaDodSO 4 gels or that the Rh mRNA may encode a precursor protein, which is further matured by a proteolytic cleavage of the C-terminal region of the polypeptide. Hydropathy analysis and secondary structure predictions suggest the presence of 13 membrane-spanning domains, indicating that the Rh polypeptide is highly hydrophobic and deeply buried within the phospholipid bilayer. These results suggest that the expression of the Rh gene(s) might be restricted to tissues or cell lines expressing erythroid characters

  13. Pituitary adenylate cyclase-activating polypeptide stimulates renin secretion via activation of PAC1 receptors

    DEFF Research Database (Denmark)

    Hautmann, Matthias; Friis, Ulla G; Desch, Michael

    2007-01-01

    Besides of its functional role in the nervous system, the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) is involved in the regulation of cardiovascular function. Therefore, PACAP is a potent vasodilator in several vascular beds, including the renal vasculature. Because...

  14. The Beads of Translation: Using Beads to Translate mRNA into a Polypeptide Bracelet

    Science.gov (United States)

    Dunlap, Dacey; Patrick, Patricia

    2012-01-01

    During this activity, by making beaded bracelets that represent the steps of translation, students simulate the creation of an amino acid chain. They are given an mRNA sequence that they translate into a corresponding polypeptide chain (beads). This activity focuses on the events and sites of translation. The activity provides students with a…

  15. Improvement of Learning and Memory Induced by Cordyceps Polypeptide Treatment and the Underlying Mechanism

    Directory of Open Access Journals (Sweden)

    Guangxin Yuan

    2018-01-01

    Full Text Available Our previous research revealed that Cordyceps militaris can improve the learning and memory, and although the main active ingredient should be its polypeptide complexes, the underlying mechanism of its activity remains poorly understood. In this study, we explored the mechanisms by which Cordyceps militaris improves learning and memory in a mouse model. Mice were given scopolamine hydrobromide intraperitoneally to establish a mouse model of learning and memory impairment. The effects of Cordyceps polypeptide in this model were tested using the Morris water maze test; serum superoxide dismutase activity; serum malondialdehyde levels; activities of acetyl cholinesterase, Na+-k+-ATPase, and nitric oxide synthase; and gamma aminobutyric acid and glutamate contents in brain tissue. Moreover, differentially expressed genes and the related cellular signaling pathways were screened using an mRNA expression profile chip. The results showed that the genes Pik3r5, Il-1β, and Slc18a2 were involved in the effects of Cordyceps polypeptide on the nervous system of these mice. Our findings suggest that Cordyceps polypeptide may improve learning and memory in the scopolamine-induced mouse model of learning and memory impairment by scavenging oxygen free radicals, preventing oxidative damage, and protecting the nervous system.

  16. Effects of vasoactive intestinal polypeptide on heart rate in relation to vagal cardioacceleration in conscious dogs

    NARCIS (Netherlands)

    Roossien, A; Brunstig, J.R; Nijmeijer, A; Zaagsma, Hans; Zijlstra, W.G

    Objective: The vagal cardiac accelerator (VCA) system takes part in the nervous control of the heart rate. In the present study we tried to adduce evidence that vasoactive intestinal polypeptide (VLP) contributes to vagally induced cardioacceleration. Methods: The effect of VIP on heart rate and

  17. Structural variation and inhibitor binding in polypeptide deformylase from four different bacterial species.

    Science.gov (United States)

    Smith, Kathrine J; Petit, Chantal M; Aubart, Kelly; Smyth, Martin; McManus, Edward; Jones, Jo; Fosberry, Andrew; Lewis, Ceri; Lonetto, Michael; Christensen, Siegfried B

    2003-02-01

    Polypeptide deformylase (PDF) catalyzes the deformylation of polypeptide chains in bacteria. It is essential for bacterial cell viability and is a potential antibacterial drug target. Here, we report the crystal structures of polypeptide deformylase from four different species of bacteria: Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, and Escherichia coli. Comparison of these four structures reveals significant overall differences between the two Gram-negative species (E. coli and H. influenzae) and the two Gram-positive species (S. pneumoniae and S. aureus). Despite these differences and low overall sequence identity, the S1' pocket of PDF is well conserved among the four enzymes studied. We also describe the binding of nonpeptidic inhibitor molecules SB-485345, SB-543668, and SB-505684 to both S. pneumoniae and E. coli PDF. Comparison of these structures shows similar binding interactions with both Gram-negative and Gram-positive species. Understanding the similarities and subtle differences in active site structure between species will help to design broad-spectrum polypeptide deformylase inhibitor molecules.

  18. Biosynthesis and characterization of typical fibroin crystalline polypeptides of silkworm Bombyx mori

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jiannan, E-mail: wangjn@suda.edu.cn [College of Material Engineering, Soochow University, Suzhou 215021 (China); Yan Shuqin [College of Material Engineering, Soochow University, Suzhou 215021 (China); Lu Changde [Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Bai Lun [College of Material Engineering, Soochow University, Suzhou 215021 (China)

    2009-05-05

    We aimed to investigate the self-organization/self-assembly mechanisms of silkworm fibroin-based material. In the present study, for the first time, we designed and multimerized four DNA 'monomer' sequences from structurally simple fibroin crystalline peptides or analog, [GAGAGX] (X = A, S, Y and V) to encode polypeptides [GAGAGX]{sub 16} (eGA, eGS, eGY and eGV) using a 'head-to-tail' construction strategy. Multimers were cloned into pGEX-KG and fusion proteins GST-[GAGAGX]{sub 16} (KGA, KGS, KGY and KGV) were efficiently expressed in Escherichia coli. These fusion proteins were isolated and purified by GST affinity chromatography and confirmed by SDS-PAGE and Western blot analysis using antibody reactive to GST. The polypeptides were cleavaged from GST fusion proteins by digesting with thrombin enzyme. The composition of the four polypeptides was confirmed by composition analysis of amino acids, and their abilities to form {beta}-sheet structure were determined by ThT fluorescence spectral analysis. The content of {beta}-sheet among the four polypeptides followed the order: eGS > eGV > eGY > eGA.

  19. TISSUE POLYPEPTIDE-SPECIFIC ANTIGEN - A DISCRIMINATIVE PARAMETER BETWEEN PROSTATE-CANCER AND BENIGN PROSTATIC HYPERTROPHY

    NARCIS (Netherlands)

    MARRINK, J; OOSTEROM, R; BONFRER, HMG; SCHRODER, FH; MENSINK, HJA

    1993-01-01

    The serum concentration of the cell proliferation marker TPS (tissue polypeptide-specific antigen) was compared with the tumour marker PSA (prostate specific antigen). PSA was found elevated in 50% of the benign prostatic hypertrophy (BPH) patients, in 88% of the patients with active prostate cancer

  20. Effects on DPPH inhibition of egg-white protein polypeptides treated by pulsed electric field technology.

    Science.gov (United States)

    Wang, Ke; Wang, Jia; Liu, Bolong; Lin, Songyi; Zhao, Ping; Liu, Jingbo; Jones, Gregory; Huang, Hsiang-Chi

    2013-05-01

    Egg-white protein polypeptides are potentially used as a functional ingredient in food products. In this study, the effects on DPPH inhibition of egg-white protein polypeptides ranging from 10 to 30 kDa treated by pulsed electric field (PEF) technology were investigated. 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) inhibition (%) was used to evaluate the antioxidant activity of polypeptides. In order to develop and optimize a pulsed electric field (PEF) mathematical model for improving the antioxidant activity, we have investigated three variables, including concentration (6, 8 and 10 mg mL(-1)), electric field intensity (10, 20 and 30 kV cm(-1)) and pulse frequency (2000, 2350 and 2700 Hz) and subsequently optimized them by response surface methodology (RSM). The concentration (8 mg mL(-1)), electric field intensity (10 kV cm(-1)) and pulse frequency (2000 Hz) were found to be the optimal conditions under which the DPPH inhibition increased 28.44%, compared to the sample without PEF treatment. Both near-infrared spectroscopy (NIR) and mid-infrared spectroscopy (MIR) were used to analyze the change of functional groups. The results showed that PEF technology could improve the antioxidant activity of antioxidant polypeptides from egg-white protein under the optimized conditions. © 2012 Society of Chemical Industry.

  1. Permanent Electric Dipole-Dipole Interactions in Lyotropic Polypeptide Liquid Crystals

    OpenAIRE

    MORI, Norio; Norio, MORI; Research Associate, Department of Industrial Chemistry

    1981-01-01

    The interaction energy between two adjacent α-helical molecules was calculated taking into account for permanent electric dipoles locating orl the helical core of a polymer mainchain in order to explain the cholesteric structure of lyotropic polypeptide liquid crystals. It was concluded that the dipole-dipole interactions were responsible for the formation of the cholesteric structure.

  2. Side-chain-controlled self-assembly of polystyrene-polypeptide miktoarm star copolymers

    KAUST Repository

    Junnila, Susanna; Houbenov, Nikolay; Karatzas, A.; Hadjichristidis, Nikolaos; Hirao, Akira; Iatrou, Hermis; Ikkala, Olli T.

    2012-01-01

    polypeptide-surfactant self-assemblies with β-sheet conformation in PS 2PLL(DS) and PS 2(PLL(DS)) 2 which dominate over the formation of block copolymer scale structures. Differences between the 3- and 4-arm systems illustrate how packing frustration between

  3. Biosynthesis and characterization of a non-repetitive polypeptide derived from silk fibroin heavy chain

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Gaoqiang; Wu, Mingyang; Yi, Honggen; Wang, Jiannan, E-mail: wangjn@suda.edu.cn

    2016-02-01

    Silk fibroin heavy chain is the major protein component of Bombyx mori silk fibroin and is composed of 12 repetitive and 11 non-repetitive regions, with the non-repetitive domain consisting of a hydrophilic polypeptide chain. In order to determine the biomedical function of the non-repetitive domain or potentially use it to modify hydrophobic biomaterials, high-purity isolation is necessary. Previously, we cloned and extended a gene motif (f(1)) encoding the non-repetitive domain. Here, this motif and its multimers are inserted into a glutathione S-transferase (GST)-tagged fusion-protein expression vector. Motif f(1) and multimers f(4) and f(8) were expressed in Escherichia coli BL21 cells following isopropyl β-D-1-thiogalactopyranoside induction, purified by GST-affinity chromatography, and single bands of purified fusion proteins GST-F(1), GST-F(4), and GST-F(8), were visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Target polypeptides F(1), F(4), and F(8), were cleaved clearly from the GST-fusion tag following thrombin digestion. Mass spectrometry results indicate that the molecular weights associated with fusion proteins GST-F(1), GST-F(4), and GST-F(8) are 31.5, 43.8, and 59.0 kDa, respectively, and with the cleaved polypeptides F(1), F(4), and F(8) are 4.8, 16.8, and 32.8 kDa, respectively. The F(1), F(4), and F(8) polypeptide chains are negatively charged with isoelectric points (pI) of 3.3, 3.2, and 3.0, respectively. The molecular weight and pI values of the polypeptide chains are consistent with the predicted values and the amino acid compositions similar to predicted sequences. FTIR and CD results show the molecular conformation of F(1) was mainly random coil, and more stable α-helix structure formed in longer molecular chain. - Highlights: • A non-repetitive domain and its multimers of silk fibroin were expressed by E. coli. • The corresponding target polypeptides F(1), F(4) and F(8) were cleaved clearly. • Their

  4. Adhesive polypeptides of Staphylococcus aureus identified using a novel secretion library technique in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Holm Liisa

    2011-05-01

    Full Text Available Abstract Background Bacterial adhesive proteins, called adhesins, are frequently the decisive factor in initiation of a bacterial infection. Characterization of such molecules is crucial for the understanding of bacterial pathogenesis, design of vaccines and development of antibacterial drugs. Because adhesins are frequently difficult to express, their characterization has often been hampered. Alternative expression methods developed for the analysis of adhesins, e.g. surface display techniques, suffer from various drawbacks and reports on high-level extracellular secretion of heterologous proteins in Gram-negative bacteria are scarce. These expression techniques are currently a field of active research. The purpose of the current study was to construct a convenient, new technique for identification of unknown bacterial adhesive polypeptides directly from the growth medium of the Escherichia coli host and to identify novel proteinaceous adhesins of the model organism Staphylococcus aureus. Results Randomly fragmented chromosomal DNA of S. aureus was cloned into a unique restriction site of our expression vector, which facilitates secretion of foreign FLAG-tagged polypeptides into the growth medium of E. coli ΔfliCΔfliD, to generate a library of 1663 clones expressing FLAG-tagged polypeptides. Sequence and bioinformatics analyses showed that in our example, the library covered approximately 32% of the S. aureus proteome. Polypeptides from the growth medium of the library clones were screened for binding to a selection of S. aureus target molecules and adhesive fragments of known staphylococcal adhesins (e.g coagulase and fibronectin-binding protein A as well as polypeptides of novel function (e.g. a universal stress protein and phosphoribosylamino-imidazole carboxylase ATPase subunit were detected. The results were further validated using purified His-tagged recombinant proteins of the corresponding fragments in enzyme-linked immunoassay and

  5. Identification and replication of the interplay of four genetic high-risk variants for urinary bladder cancer.

    Science.gov (United States)

    Selinski, Silvia; Blaszkewicz, Meinolf; Ickstadt, Katja; Gerullis, Holger; Otto, Thomas; Roth, Emanuel; Volkert, Frank; Ovsiannikov, Daniel; Moormann, Oliver; Banfi, Gergely; Nyirady, Peter; Vermeulen, Sita H; Garcia-Closas, Montserrat; Figueroa, Jonine D; Johnson, Alison; Karagas, Margaret R; Kogevinas, Manolis; Malats, Nuria; Schwenn, Molly; Silverman, Debra T; Koutros, Stella; Rothman, Nathaniel; Kiemeney, Lambertus A; Hengstler, Jan G; Golka, Klaus

    2017-12-07

    Little is known whether genetic variants identified in genome-wide association studies interact to increase bladder cancer risk. Recently, we identified two- and three-variant combinations associated with a particular increase of bladder cancer risk in a urinary bladder cancer case-control series (Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund (IfADo), 1501 cases, 1565 controls). In an independent case-control series (Nijmegen Bladder Cancer Study, NBCS, 1468 cases, 1720 controls) we confirmed these two- and three-variant combinations. Pooled analysis of the two studies as discovery group (IfADo-NBCS) resulted in sufficient statistical power to test up to four-variant combinations by a logistic regression approach. The New England and Spanish Bladder Cancer Studies (2080 cases and 2167 controls) were used as a replication series. Twelve previously identified risk variants were considered. The strongest four-variant combination was obtained in never smokers. The combination of rs1014971[AA] near apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3A (APOBEC3A) and chromobox homolog 6 (CBX6), solute carrier family 1s4 (urea transporter), member 1 (Kidd blood group) (SLC14A1) exon single nucleotide polymorphism (SNP) rs1058396[AG, GG], UDP glucuronosyltransferase 1 family, polypeptide A complex locus (UGT1A) intron SNP rs11892031[AA] and rs8102137[CC, CT] near cyclin E1 (CCNE1) resulted in an unadjusted odds ratio (OR) of 2.59 (95% CI = 1.93-3.47; P = 1.87 × 10-10), while the individual variant ORs ranged only between 1.11 and 1.30. The combination replicated in the New England and Spanish Bladder Cancer Studies (ORunadjusted = 1.60, 95% CI = 1.10-2.33; P = 0.013). The four-variant combination is relatively frequent, with 25% in never smoking cases and 11% in never smoking controls (total study group: 19% cases, 14% controls). In conclusion, we show that four high-risk variants can statistically interact to confer

  6. Zonadhesin D3-polypeptides vary among species but are similar in Equus species capable of interbreeding.

    Science.gov (United States)

    Tardif, Steve; Brady, Heidi A; Breazeale, Kelly R; Bi, Ming; Thompson, Leslie D; Bruemmer, Jason E; Bailey, Laura B; Hardy, Daniel M

    2010-02-01

    Zonadhesin is a rapidly evolving protein in the sperm acrosome that confers species specificity to sperm-zona pellucida adhesion. Though structural variation in zonadhesin likely contributes to its species-specific function, the protein has not previously been characterized in organisms capable of interbreeding. Here we compared properties of zonadhesin in several animals, including the horse (Equus caballus), donkey (E. asinus), and Grevy's zebra (E. grevyi) to determine if variation in zonadhesin correlates with ability of gametes to cross-fertilize. Zonadhesin localized to the apical acrosomes of spermatozoa from all three Equus species, similar to its localization in other animals. Likewise, in horse and donkey testis, zonadhesin was detected only in germ cells, first in the acrosomal granule of round spermatids and then in the developing acrosomes of elongating spermatids. Among non-Equus species, D3-domain polypeptides of mature, processed zonadhesin varied markedly in size and detergent solubility. However, zonadhesin D3-domain polypeptides in horse, donkey, and zebra spermatozoa exhibited identical electrophoretic mobility and detergent solubility. Equus zonadhesin D3-polypeptides (p110/p80 doublet) were most similar in size to porcine and bovine zonadhesin D3-polypeptides (p105). Sequence comparisons revealed that the horse zonadhesin precursor's domain content and arrangement are similar to those of zonadhesin from other large animals. Partial sequences of horse and donkey zonadhesin were much more similar to each other (>99% identity) than they were to orthologous sequences of human, pig, rabbit, and mouse zonadhesin (52%-72% identity). We conclude that conservation of zonadhesin D3-polypeptide properties correlates with ability of Equus species to interbreed.

  7. Pituitary adenylate cyclase activating polypeptide reduces A-type K+ currents and caspase activity in cultured adult mouse olfactory neurons.

    Science.gov (United States)

    Han, P; Lucero, M T

    2005-01-01

    Pituitary adenylate cyclase activating polypeptide has been shown to reduce apoptosis in neonatal cerebellar and olfactory receptor neurons, however the underlying mechanisms have not been elucidated. In addition, the neuroprotective effects of pituitary adenylate cyclase activating polypeptide have not been examined in adult tissues. To study the effects of pituitary adenylate cyclase activating polypeptide on neurons in apoptosis, we measured caspase activation in adult olfactory receptor neurons in vitro. Interestingly, we found that the protective effects of pituitary adenylate cyclase activating polypeptide were related to the absence of a 4-aminopyridine (IC50=144 microM) sensitive rapidly inactivating potassium current often referred to as A-type current. In the presence of 40 nM pituitary adenylate cyclase activating polypeptide 38, both A-type current and activated caspases were significantly reduced. A-type current reduction by pituitary adenylate cyclase activating polypeptide was blocked by inhibiting the phospholipase C pathway, but not the adenylyl cyclase pathway. Our observation that 5 mM 4-aminopyridine mimicked the caspase inhibiting effects of pituitary adenylate cyclase activating polypeptide indicates that A-type current is involved in apoptosis. This work contributes to our growing understanding that potassium currents are involved with the activation of caspases to affect the balance between cell life and death.

  8. Immunoassay of serum polypeptide hormones by using 125I-labelled anti(-immunoglobulin G) antibodies.

    Science.gov (United States)

    Beck, P; Nicholas, H

    1975-03-01

    1. A technique for indirectly labelling antibodies to polypeptide hormones, by combining them with radioactively labelled anti-(immunoglobulin G) is described. (a) 125I-labelled anti-(rabbit immunoglobulin G) and anti-(guinea-pig immunoglobulin G) antibodies with high specific radioactivity were prepared after purification of the antibodies on immunoadsorbents containing the respective antigens. (b) Rabbit immunoglobulin G antibodies to human growth hormone, porcine glucagon and guinea-pig immunoglobulin G antibodies to bovine insulin and bovine parathyroid hormone were combined with immunoadsorbents containing the respective polypeptide hormone antigen. (c) The immunoglobulin G antibodies to the polypeptide hormones were reacted with 125-I-labelled anti-(immunoglobulin G) antibodies directed against the appropriate species of immunoglobulin G,and the anti-hormone antibodies were combined with the hormone-containing immunoadsorbent. (d) 125I-labelled anti-(immunoglobulin G) antibodies and anti-hormone antibodies were simultaneously eluted from the hormone-containing immunoadsorbent by dilute HCl, pH 2.0. After elution the anti-(immunoglobulin G) antibodies and antihormone antibodies were allowed to recombine at pH 8.0 and 4 degrees C. 2. The resultant immunoglobulin G-anti-immunoglobulin G complex was used in immunoradiometric (labelled antibody) and two-site assays of the respective polypeptide hormone. 3. By using these immunoassays, concentrations down to 90pg of human growth hormone/ml, 100 pg of bovine insulin/ml, 80 pg of bovine parathyroid hormone/ml and 150 pg of glucagon/ml were readily detected. Assays of human plasma for growth hormone and insulin by these methods showed good agreement with results obtained by using a directly 125I-labelled anti-hormone antibody in an immunoradiometric assay of human growth hormone or by radioimmunoassay of human insulin. 4. The method described allows immunoradiometric or two-site assays to be performed starting with as

  9. Data-variant kernel analysis

    CERN Document Server

    Motai, Yuichi

    2015-01-01

    Describes and discusses the variants of kernel analysis methods for data types that have been intensely studied in recent years This book covers kernel analysis topics ranging from the fundamental theory of kernel functions to its applications. The book surveys the current status, popular trends, and developments in kernel analysis studies. The author discusses multiple kernel learning algorithms and how to choose the appropriate kernels during the learning phase. Data-Variant Kernel Analysis is a new pattern analysis framework for different types of data configurations. The chapters include

  10. Self-assembling chimeric polypeptide-doxorubicin conjugate nanoparticles that abolish tumours after a single injection

    Science.gov (United States)

    Andrew Mackay, J.; Chen, Mingnan; McDaniel, Jonathan R.; Liu, Wenge; Simnick, Andrew J.; Chilkoti, Ashutosh

    2009-12-01

    New strategies to self-assemble biocompatible materials into nanoscale, drug-loaded packages with improved therapeutic efficacy are needed for nanomedicine. To address this need, we developed artificial recombinant chimeric polypeptides (CPs) that spontaneously self-assemble into sub-100-nm-sized, near-monodisperse nanoparticles on conjugation of diverse hydrophobic molecules, including chemotherapeutics. These CPs consist of a biodegradable polypeptide that is attached to a short Cys-rich segment. Covalent modification of the Cys residues with a structurally diverse set of hydrophobic small molecules, including chemotherapeutics, leads to spontaneous formation of nanoparticles over a range of CP compositions and molecular weights. When used to deliver chemotherapeutics to a murine cancer model, CP nanoparticles have a fourfold higher maximum tolerated dose than free drug, and induce nearly complete tumour regression after a single dose. This simple strategy can promote co-assembly of drugs, imaging agents and targeting moieties into multifunctional nanomedicines.

  11. Effect of Sequence Blockiness on the Morphologies of Surface-grafted Elastin-like Polypeptides

    Science.gov (United States)

    Albert, Julie; Sintavanon, Kornkanok; Mays, Robin; MacEwan, Sarah; Chilkoti, Ashutosh; Genzer, Jan

    2014-03-01

    The inter- and intra- molecular interactions among monomeric units of copolymers and polypeptides depend strongly on monomer sequence distribution and dictate the phase behavior of these species both in solution and on surfaces. To study the relationship between sequence and phase behavior, we have designed a series of elastin-like polypeptides (ELPs) with controlled monomer sequences that mimic copolymers with various co-monomer sequence distributions and attached them covalently to silicon substrates from buffer solutions at temperatures below and above the bulk ELPs' lower critical solution temperatures (LCSTs). The dependence of ELP grafting density on solution temperature was examined by ellipsometry and the resultant surface morphologies were examined in air and under water with atomic force microscopy. Depositions performed above the LCST resulted in higher grafting densities and greater surface roughness of ELPs relative to depositions carried out below the LCST. In addition, we are using gradient substrates to examine the effect of ELP grafting density on temperature responsiveness.

  12. Elastin-like polypeptides: Therapeutic applications for an emerging class of nanomedicines.

    Science.gov (United States)

    Despanie, Jordan; Dhandhukia, Jugal P; Hamm-Alvarez, Sarah F; MacKay, J Andrew

    2016-10-28

    Elastin-like polypeptides (ELPs) constitute a genetically engineered class of 'protein polymers' derived from human tropoelastin. They exhibit a reversible phase separation whereby samples remain soluble below a transition temperature (T t ) but form amorphous coacervates above T t . Their phase behavior has many possible applications in purification, sensing, activation, and nanoassembly. As humanized polypeptides, they are non-immunogenic, substrates for proteolytic biodegradation, and can be decorated with pharmacologically active peptides, proteins, and small molecules. Recombinant synthesis additionally allows precise control over ELP architecture and molecular weight, resulting in protein polymers with uniform physicochemical properties suited to the design of multifunctional biologics. As such, ELPs have been employed for various uses including as anti-cancer agents, ocular drug delivery vehicles, and protein trafficking modulators. This review aims to offer the reader a catalogue of ELPs, their various applications, and potential for commercialization across a broad spectrum of fields. Copyright © 2015. Published by Elsevier B.V.

  13. Dynamic enzyme docking to the ribosome coordinates N-terminal processing with polypeptide folding.

    Science.gov (United States)

    Sandikci, Arzu; Gloge, Felix; Martinez, Michael; Mayer, Matthias P; Wade, Rebecca; Bukau, Bernd; Kramer, Günter

    2013-07-01

    Newly synthesized polypeptides undergo various cotranslational maturation steps, including N-terminal enzymatic processing, chaperone-assisted folding and membrane targeting, but the spatial and temporal coordination of these steps is unclear. We show that Escherichia coli methionine aminopeptidase (MAP) associates with ribosomes through a charged loop that is crucial for nascent-chain processing and cell viability. MAP competes with peptide deformylase (PDF), the first enzyme to act on nascent chains, for binding sites at the ribosomal tunnel exit. PDF has extremely fast association and dissociation kinetics, which allows it to frequently sample ribosomes and ensure the processing of nascent chains after their emergence. Premature recruitment of the chaperone trigger factor, or polypeptide folding, negatively affect processing efficiency. Thus, the fast ribosome association kinetics of PDF and MAP are crucial for the temporal separation of nascent-chain processing from later maturation events, including chaperone recruitment and folding.

  14. Polypeptide composition of fraction 1 protein of the somatic hybrid between Petunia parodii and Petunia parviflora.

    Science.gov (United States)

    Kumar, A; Wilson, D; Cocking, E C

    1981-04-01

    The analysis of the subunit polypeptide composition of Fraction 1 protein provides information on the expression of both chloroplast and nuclear genomes. Fraction 1 protein, isolated from leaves of the somatic hybrid plants derived form the fusion of protoplasts of Petunia parodii and P. parviflora, was analyzed for its subunit polypeptide composition by isoelectric focusing in 8 M urea. The fraction 1 protein enzyme oligomer in the somatic hybrid plants contained small subunits resulting from the expression of both parental nuclear genomes, but probably only one of the parental large subunits, namely that of P. parodii. The relevance of such somatic hybrid material for the study of nucleocytoplasmic interrelationship is discussed, as well as the use of these fraction 1 protein isoelectric focusing patterns for the analysis of taxonomic relationships in Petunia.

  15. Homoallylglycine residues are superior precursors to orthogonally modified thioether containing polypeptides.

    Science.gov (United States)

    Perlin, Pesach; Gharakhanian, Eric G; Deming, Timothy J

    2018-06-12

    Homoallylglycine N-carboxyanhydride, Hag NCA, monomers were synthesized and used to prepare polypeptides containing Hag segments with controllable lengths of up to 245 repeats. Poly(l-homoallylglycine), GHA, was found to adopt an α-helical conformation, which provided good solubility in organic solvents and allowed high yield functionalization of its alkene side-chains via radical promoted addition of thiols. The conformations of these derivatives were shown to be switchable between α-helical and disordered states in aqueous media using thioether alkylation or oxidation reactions. Incorporation of GHA segments into block copolymers with poly(l-methionine), M, segments provided a means to orthogonally modify thioether side-chains different ways in separate copolypeptide domains. This approach allows preparation of functional polypeptides containing discrete domains of oxidized and alkylated thioether containing residues, where chain conformation and functionality of each domain can be independently modified.

  16. Wall-associated kinase-like polypeptide mediates nutritional status perception and response

    Science.gov (United States)

    Yang, Zhenbiao; Karr, Stephen

    2014-02-11

    The disclosure relates to methods for modulating plant growth and organogenesis using dominant-negative receptor-like kinases. The disclosure further provides a method for increasing plant yield relative to corresponding wild type plants comprising modulating the expression in a plant of a nucleic acid encoding a Wall-Associated Kinase-like 14 polypeptide or a homolog thereof, and selecting for plants having increased yield or growth on a nutrient deficient substrate.

  17. Islet amyloid polypeptide in the control of food intake : An experimental study in the rat

    OpenAIRE

    Arnelo, Urban

    1997-01-01

    Control of food intake and satiety are physiologically complex processes, thatonly partly are understood. Several hormonal peptides have been proposed to mediatesatiety. Islet amyloid polypeptide (IAPP) is a recently discovered 37 amino acidpeptide, mainly produced by the pancreatic ß-cells. Initially, IAPP was shownto impair glucose tolerance at supra-physiological plasma concentrations and wasspeculated to be involved in the development of type-2 diabetes. More recent stud...

  18. Sustained Release of Antibiotics from Injectable and Thermally Responsive Polypeptide Depots

    OpenAIRE

    Adams, Samuel B.; Shamji, Mohammed F.; Nettles, Dana L.; Hwang, Priscilla; Setton, Lori A.

    2009-01-01

    Biodegradable polymeric scaffolds are of interest for delivering antibiotics to local sites of infection in orthopaedic applications, such as bone and diarthrodial joints. The objective of this study was to develop a biodegradable scaffold with ease of drug loading in aqueous solution, while providing for drug depot delivery via syringe injection. Elastin-like polypeptides (ELPs) were used for this application, biopolymers of repeating pentapeptide sequences that were thermally triggered to u...

  19. Folding and self-assembly of polypeptides: Dynamics and thermodynamics from molecular simulation

    Science.gov (United States)

    Fluitt, Aaron Michael

    Empowered by their exquisite three-dimensional structures, or "folds," proteins carry out biological tasks with high specificity, efficiency, and fidelity. The fold that optimizes biological function represents a stable configuration of the constituent polypeptide molecule(s) under physiological conditions. Proteins and polypeptides are not static, however: battered by thermal motion, they explore a distribution of folds that is determined by the sequence of amino acids, the presence and identity of other molecules, and the thermodynamic conditions. In this dissertation, we apply molecular simulation techniques to the study of two polypeptides that have unusually diffuse distributions of folds under physiological conditions: polyglutamine (polyQ) and islet amyloid polypeptide (IAPP). Neither polyQ nor IAPP adopts a predominant fold in dilute aqueous solution, but at sufficient concentrations, both are prone to self-assemble into stable, periodic, and highly regular aggregate structures known as amyloid. The appearance of amyloid deposits of polyQ in the brain, and of IAPP in the pancreas, are associated with Huntington's disease and type 2 diabetes, respectively. A molecular view of the mechanism(s) by which polyQ and IAPP fold and self-assemble will enhance our understanding of disease pathogenesis, and it has the potential to accelerate the development of therapeutics that target early-stage aggregates. Using molecular simulations with spatial and temporal resolution on the atomic scale, we present analyses of the structural distributions of polyQ and IAPP under various conditions, both in and out of equilibrium. In particular, we examine amyloid fibers of polyQ, the IAPP dimer in solution, and single IAPP fragments at a lipid bilayer. We also benchmark the molecular models, or "force fields," available for such studies, and we introduce a novel simulation algorithm.

  20. Vasoactive intestinal polypeptide (VIP) tissue distribution in the rat as measured by radioimmunoassay and by radioreceptorassay

    International Nuclear Information System (INIS)

    Besson, J.; Dupont, C.; Laburthe, M.; Bataille, D.; Rosselin, G.

    1977-01-01

    A new radioimmunoassay which allows the measurement of the rat vasoactive intestinal polypeptide, was performed. VIP is present in the whole digestive tract of rat, mainly between the duodenum and the colon. 1.5% of the total VIP is present in brain. The VIP-like immunoreactivity appears to correspond to biologically active molecule since a radioreceptorassay using liver plasma membranes as the target tissue, gives the same results as the radioimmunoassay [fr

  1. Heterozygous RFX6 protein truncating variants are associated with MODY with reduced penetrance.

    Science.gov (United States)

    Patel, Kashyap A; Kettunen, Jarno; Laakso, Markku; Stančáková, Alena; Laver, Thomas W; Colclough, Kevin; Johnson, Matthew B; Abramowicz, Marc; Groop, Leif; Miettinen, Päivi J; Shepherd, Maggie H; Flanagan, Sarah E; Ellard, Sian; Inagaki, Nobuya; Hattersley, Andrew T; Tuomi, Tiinamaija; Cnop, Miriam; Weedon, Michael N

    2017-10-12

    Finding new causes of monogenic diabetes helps understand glycaemic regulation in humans. To find novel genetic causes of maturity-onset diabetes of the young (MODY), we sequenced MODY cases with unknown aetiology and compared variant frequencies to large public databases. From 36 European patients, we identify two probands with novel RFX6 heterozygous nonsense variants. RFX6 protein truncating variants are enriched in the MODY discovery cohort compared to the European control population within ExAC (odds ratio = 131, P = 1 × 10 -4 ). We find similar results in non-Finnish European (n = 348, odds ratio = 43, P = 5 × 10 -5 ) and Finnish (n = 80, odds ratio = 22, P = 1 × 10 -6 ) replication cohorts. RFX6 heterozygotes have reduced penetrance of diabetes compared to common HNF1A and HNF4A-MODY mutations (27, 70 and 55% at 25 years of age, respectively). The hyperglycaemia results from beta-cell dysfunction and is associated with lower fasting and stimulated gastric inhibitory polypeptide (GIP) levels. Our study demonstrates that heterozygous RFX6 protein truncating variants are associated with MODY with reduced penetrance.Maturity-onset diabetes of the young (MODY) is the most common subtype of familial diabetes. Here, Patel et al. use targeted DNA sequencing of MODY patients and large-scale publically available data to show that RFX6 heterozygous protein truncating variants cause reduced penetrance MODY.

  2. Study of local conformation and molecular movements of homo-polypeptides in aqueous solutions by using magnetic resonance and relaxation

    International Nuclear Information System (INIS)

    Perly, Bruno

    1980-01-01

    The objective of this research thesis is to study local conformations and mobilities of some typical homo-polypeptides by using techniques of magnetic resonance. By using these techniques, it is possible to make highly local observations of molecular elements which allows very efficient analysis of structural and dynamic properties of several biologically important compounds to be performed, and the study of their interactions. After a presentation of the general properties of the studied polypeptides, of magnetic resonance and of magnetic relaxation, the author presents some elements of macromolecular dynamics and movement models. Then, he reports the study of local conformations and structural transitions, applications of spin marking to the dynamic study of polypeptides, a dynamic study of the polypeptide skeleton under the form of statistic balls, the study of local movements of side chains by using nuclear relaxation, the study of the coupling of movements of main and side chains, and of the nuclear relaxation induced by a radical spin marker

  3. Role of Side-Chain Molecular Features in Tuning Lower Critical Solution Temperatures (LCSTs) of Oligoethylene Glycol Modified Polypeptides.

    Science.gov (United States)

    Gharakhanian, Eric G; Deming, Timothy J

    2016-07-07

    A series of thermoresponsive polypeptides has been synthesized using a methodology that allowed facile adjustment of side-chain functional groups. The lower critical solution temperature (LCST) properties of these polymers in water were then evaluated relative to systematic molecular modifications in their side-chains. It was found that in addition to the number of ethylene glycol repeats in the side-chains, terminal and linker groups also have substantial and predictable effects on cloud point temperatures (Tcp). In particular, we found that the structure of these polypeptides allowed for inclusion of polar hydroxyl groups, which significantly increased their hydrophilicity and decreased the need to use long oligoethylene glycol repeats to obtain LCSTs. The thioether linkages in these polypeptides were found to provide an additional structural feature for reversible switching of both polypeptide conformation and thermoresponsive properties.

  4. GCPII Variants, Paralogs and Orthologs

    Czech Academy of Sciences Publication Activity Database

    Hlouchová, Klára; Navrátil, Václav; Tykvart, Jan; Šácha, Pavel; Konvalinka, Jan

    2012-01-01

    Roč. 19, č. 9 (2012), s. 1316-1322 ISSN 0929-8673 R&D Projects: GA ČR GAP304/12/0847 Institutional research plan: CEZ:AV0Z40550506 Keywords : PSMA * GCPIII * NAALADase L * splice variants * homologs * PSMAL Subject RIV: CE - Biochemistry Impact factor: 4.070, year: 2012

  5. Odontogenic keratocyst: a peripheral variant.

    Science.gov (United States)

    Vij, H; Vij, R; Gupta, V; Sengupta, S

    2011-01-01

    Odontogenic keratocyst, which is developmental in nature, is an intraosseous lesion though on rare occasions it may occur in an extraosseous location. The extraosseous variant is referred to as peripheral odontogenic keratocyst. Though, clinically, peripheral odontogenic keratocyst resembles the gingival cyst of adults, it has histologic features that are pathognomonic of odontogenic keratocyst. This article presents a case of this uncommon entity.

  6. Strategies to Fabricate Polypeptide-Based Structures via Ring-Opening Polymerization of N-Carboxyanhydrides

    Directory of Open Access Journals (Sweden)

    Carmen M. González-Henríquez

    2017-10-01

    Full Text Available In this review, we provide a general and clear overview about the different alternatives reported to fabricate a myriad of polypeptide architectures based on the ring-opening polymerization of N-carbonyanhydrides (ROP NCAs. First of all, the strategies for the preparation of NCA monomers directly from natural occurring or from modified amino acids are analyzed. The synthetic alternatives to prepare non-functionalized and functionalized NCAs are presented. Protection/deprotection protocols, as well as other functionalization chemistries are discussed in this section. Later on, the mechanisms involved in the ROP NCA polymerization, as well as the strategies developed to reduce the eventually occurring side reactions are presented. Finally, a general overview of the synthetic strategies described in the literature to fabricate different polypeptide architectures is provided. This part of the review is organized depending on the complexity of the macromolecular topology prepared. Therefore, linear homopolypeptides, random and block copolypeptides are described first. The next sections include cyclic and branched polymers such as star polypeptides, polymer brushes and highly branched structures including arborescent or dendrigraft structures.

  7. Salt- and pH-Triggered Helix-Coil Transition of Ionic Polypeptides under Physiology Conditions.

    Science.gov (United States)

    Yuan, Jingsong; Zhang, Yi; Sun, Yue; Cai, Zhicheng; Yang, Lijiang; Lu, Hua

    2018-06-11

    Controlling the helix-coil transition of polypeptides under physiological conditions is an attractive way toward smart functional materials. Here, we report the synthesis of a series of tertiary amine-functionalized ethylene glycol (EG x )-linked polypeptide electrolytes with their secondary structures tunable under physiological conditions. The resultant polymers, denoted as P(EG x DMA-Glu) ( x = 1, 2, and 3), show excellent aqueous solubility (>20 mg/mL) regardless of their charge states. Unlike poly-l-lysine that can form a helix only at pH above 10, P(EG x DMA-Glu) undergo a pH-dependent helix-coil switch with their transition points within the physiological range (pH ∼5.3-6.5). Meanwhile, P(EG x DMA-Glu) exhibit an unusual salt-induced helical conformation presumably owing to the unique properties of EG x linkers. Together, the current work highlights the importance of fine-tuning the linker chemistry in achieving conformation-switchable polypeptides and represents a facile approach toward stimuli-responsive biopolymers for advanced biological applications.

  8. Sequence Directionality Dramatically Affects LCST Behavior of Elastin-Like Polypeptides.

    Science.gov (United States)

    Li, Nan K; Roberts, Stefan; Quiroz, Felipe Garcia; Chilkoti, Ashutosh; Yingling, Yaroslava G

    2018-04-30

    Elastin-like polypeptides (ELP) exhibit an inverse temperature transition or lower critical solution temperature (LCST) transition phase behavior in aqueous solutions. In this paper, the thermal responsive properties of the canonical ELP, poly(VPGVG), and its reverse sequence poly(VGPVG) were investigated by turbidity measurements of the cloud point behavior, circular dichroism (CD) measurements, and all-atom molecular dynamics (MD) simulations to gain a molecular understanding of mechanism that controls hysteretic phase behavior. It was shown experimentally that both poly(VPGVG) and poly(VGPVG) undergo a transition from soluble to insoluble in aqueous solution upon heating above the transition temperature ( T t ). However, poly(VPGVG) resolubilizes upon cooling below its T t , whereas the reverse sequence, poly(VGPVG), remains aggregated despite significant undercooling below the T t . The results from MD simulations indicated that a change in sequence order results in significant differences in the dynamics of the specific residues, especially valines, which lead to extensive changes in the conformations of VPGVG and VGPVG pentamers and, consequently, dissimilar propensities for secondary structure formation and overall structure of polypeptides. These changes affected the relative hydrophilicities of polypeptides above T t , where poly(VGPVG) is more hydrophilic than poly(VPGVG) with more extended conformation and larger surface area, which led to formation of strong interchain hydrogen bonds responsible for stabilization of the aggregated phase and the observed thermal hysteresis for poly(VGPVG).

  9. Common spectrum of polypeptides occurs in secretion granule membranes of different exocrine glands

    International Nuclear Information System (INIS)

    Cameron, R.S.; Cameron, P.L.; Castle, J.D.

    1986-01-01

    A highly purified membrane preparation from rat parotid secretion granules has been used as a comparative probe to examine the extent of compositional overlap in granule membranes of three other exocrine secretory tissues - pancreatic, lacrimal, and submandibular - from several standpoints. First, indirect immunofluorescent studies using a polyclonal polyspecific anti-parotid granule membrane antiserum has indicated a selective staining of granule membrane profiles in all acinar cells of all tissues. Second, highly purified granule membrane subfractions have been isolated from each exocrine tissue; comparative two-dimensional (isoelectric focusing; SDS) PAGE of radioiodinated granule membranes has identified 10-15 polypeptides of identical pI and apparent molecular mass. These species are likely to be integral membrane components since they are not extracted by either saponin-sodium sulfate or sodium carbonate (pH 11.5) treatments, and they do not have counterparts in the granule content. Finally, the identity among selected parotid and pancreatic radioiodinated granule membrane polypeptides has been documented using two-dimensional peptide mapping of chymotryptic and tryptic digests. These findings clearly indicate that exocrine secretory granules, irrespective of the nature of stored secretion, comprise a type of vesicular carrier with a common (and probably refined) membrane composition. Conceivably, the polypeptides identified carry out general functions related to exocrine secretion

  10. High-yield recombinant expression and purification of marginally soluble, short elastin-like polypeptides.

    Science.gov (United States)

    Bahniuk, Markian S; Alshememry, Abdullah K; Unsworth, Larry D

    2016-12-01

    The protocol described here is designed as an extension of existing techniques for creating elastin-like polypeptides. It allows for the expression and purification of elastin-like polypeptide (ELP) constructs that are poorly expressed or have very low transition temperatures. DNA concatemerization has been modified to reduce issues caused by methylation sensitivity and inefficient cloning. Linearization of the modified expression vector has been altered to greatly increase cleavage efficiency. The purification regimen is based upon using denaturing metal affinity chromatography to fully solubilize and, if necessary, pre-concentrate the target peptide before purification by inverse temperature cycling (ITC). This protocol has been used to express multiple leucine-containing elastin-like polypeptides, with final yields of 250-660 mg per liter of cells, depending on the specific construct. This was considerably greater than previously reported yields for similar ELPs. Due to the relative hydrophobicity of the tested constructs, even compared with commonly employed ELPs, conventional methods would not have been able to be purify these peptides.

  11. Double-hydrophobic elastin-like polypeptides with added functional motifs: Self-assembly and cytocompatibility.

    Science.gov (United States)

    Le, Duc H T; Tsutsui, Yoko; Sugawara-Narutaki, Ayae; Yukawa, Hiroshi; Baba, Yoshinobu; Ohtsuki, Chikara

    2017-09-01

    We have recently developed a novel double-hydrophobic elastin-like triblock polypeptide called GPG, designed after the uneven distribution of two different hydrophobic domains found in elastin, an extracellular matrix protein providing elasticity and resilience to tissues. Upon temperature trigger, GPG undergoes a sequential self-assembling process to form flexible beaded nanofibers with high homogeneity and excellent dispersibility in water. Given that GPG might be a potential elastin-mimetic material, we sought to explore the biological activities of this block polypeptide. Besides GPG, several functionalized derivatives were also constructed by fusing functional motifs such as KAAK or KAAKGRGDS at the C-terminal of GPG. Although the added motifs affected the kinetics of fiber formation and β-sheet contents, all three GPGs assembled into beaded nanofibers at the physiological temperature. The resulting GPG nanofibers preserved their beaded structures in cell culture medium; therefore, they were coated on polystyrene substrates to study their cytocompatibility toward mouse embryonic fibroblasts, NIH-3T3. Among the three polypeptides, GPG having the cell-binding motif GRGDS derived from fibronectin showed excellent cell adhesion and cell proliferation properties compared to other conventional materials, suggesting its promising applications as extracellular matrices for mammalian cells. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2475-2484, 2017. © 2017 Wiley Periodicals, Inc.

  12. Kinetics of Internal-Loop Formation in Polypeptide Chains: A Simulation Study

    Science.gov (United States)

    Doucet, Dana; Roitberg, Adrian; Hagen, Stephen J.

    2007-01-01

    The speed of simple diffusional motions, such as the formation of loops in the polypeptide chain, places one physical limit on the speed of protein folding. Many experimental studies have explored the kinetics of formation of end-to-end loops in polypeptide chains; however, protein folding more often requires the formation of contacts between interior points on the chain. One expects that, for loops of fixed contour length, interior loops will form more slowly than end-to-end loops, owing to the additional excluded volume associated with the “tails”. We estimate the magnitude of this effect by generating ensembles of randomly coiled, freely jointed chains, and then using the theory of Szabo, Schulten, and Schulten to calculate the corresponding contact formation rates for these ensembles. Adding just a few residues, to convert an end-to-end loop to an internal loop, sharply decreases the contact rate. Surprisingly, the relative change in rate increases for a longer loop; sufficiently long tails, however, actually reverse the effect and accelerate loop formation slightly. Our results show that excluded volume effects in real, full-length polypeptides may cause the rates of loop formation during folding to depart significantly from the values derived from recent loop-formation experiments on short peptides. PMID:17208979

  13. Stimuli-Triggered Sol-Gel Transitions of Polypeptides Derived from α-Amino Acid N-Carboxyanhydride (NCA) Polymerizations.

    Science.gov (United States)

    He, Xun; Fan, Jingwei; Wooley, Karen L

    2016-02-18

    The past decade has witnessed significantly increased interest in the development of smart polypeptide-based organo- and hydrogel systems with stimuli responsiveness, especially those that exhibit sol-gel phase-transition properties, with an anticipation of their utility in the construction of adaptive materials, sensor designs, and controlled release systems, among other applications. Such developments have been facilitated by dramatic progress in controlled polymerizations of α-amino acid N-carboxyanhydrides (NCAs), together with advanced orthogonal functionalization techniques, which have enabled economical and practical syntheses of well-defined polypeptides and peptide hybrid polymeric materials. One-dimensional stacking of polypeptides or peptide aggregations in the forms of certain ordered conformations, such as α helices and β sheets, in combination with further physical or chemical cross-linking, result in the construction of three-dimensional matrices of polypeptide gel systems. The macroscopic sol-gel transitions, resulting from the construction or deconstruction of gel networks and the conformational changes between secondary structures, can be triggered by external stimuli, including environmental factors, electromagnetic fields, and (bio)chemical species. Herein, the most recent advances in polypeptide gel systems are described, covering synthetic strategies, gelation mechanisms, and stimuli-triggered sol-gel transitions, with the aim of demonstrating the relationships between chemical compositions, supramolecular structures, and responsive properties of polypeptide-based organo- and hydrogels. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Swine Influenza/Variant Influenza Viruses

    Science.gov (United States)

    ... Address What's this? Submit What's this? Submit Button Influenza Types Seasonal Avian Swine Variant Pandemic Other Information on Swine Influenza/Variant Influenza Virus Language: English (US) Español Recommend ...

  15. Sampling the Denatured State of Polypeptides in Water, Urea, and Guanidine Chloride to Strict Equilibrium Conditions with the Help of Massively Parallel Computers.

    Science.gov (United States)

    Meloni, Roberto; Camilloni, Carlo; Tiana, Guido

    2014-02-11

    The denatured state of polypeptides and proteins, stabilized by chemical denaturants like urea and guanidine chloride, displays residual secondary structure when studied by nuclear-magnetic-resonance spectroscopy. However, these experimental techniques are weakly sensitive, and thus molecular-dynamics simulations can be useful to complement the experimental findings. To sample the denatured state, we made use of massively-parallel computers and of a variant of the replica exchange algorithm, in which the different branches, connected with unbiased replicas, favor the formation and disruption of local secondary structure. The algorithm is applied to the second hairpin of GB1 in water, in urea, and in guanidine chloride. We show with the help of different criteria that the simulations converge to equilibrium. It results that urea and guanidine chloride, besides inducing some polyproline-II structure, have different effect on the hairpin. Urea disrupts completely the native region and stabilizes a state which resembles a random coil, while guanidine chloride has a milder effect.

  16. Coronary artery anatomy and variants

    Energy Technology Data Exchange (ETDEWEB)

    Malago, Roberto; Pezzato, Andrea; Barbiani, Camilla; Alfonsi, Ugolino; Nicoli, Lisa; Caliari, Giuliana; Pozzi Mucelli, Roberto [Policlinico G.B. Rossi, University of Verona, Department of Radiology, Verona (Italy)

    2011-12-15

    Variants and congenital anomalies of the coronary arteries are usually asymptomatic, but may present with severe chest pain or cardiac arrest. The introduction of multidetector CT coronary angiography (MDCT-CA) allows the detection of significant coronary artery stenosis. Improved performance with isotropic spatial resolution and higher temporal resolution provides a valid alternative to conventional coronary angiography (CCA) in many patients. MDCT-CA is now considered the ideal tool for three-dimensional visualization of the complex and tortuous anatomy of the coronary arteries. With multiplanar and volume-rendered reconstructions, MDCT-CA may even outperform CCA in determining the relative position of vessels, thus providing a better view of the coronary vascular anatomy. The purpose of this review is to describe the normal anatomy of the coronary arteries and their main variants based on MDCT-CA with appropriate reconstructions. (orig.)

  17. Microcystic Variant of Urothelial Carcinoma

    Directory of Open Access Journals (Sweden)

    Anthony Kodzo-Grey Venyo

    2013-01-01

    Full Text Available Background. Microcystic variant of urothelial carcinoma is one of the new variants of urothelial carcinoma that was added to the WHO classification in 2004. Aims. To review the literature on microcystic variant of urothelial carcinoma. Methods. Various internet search engines were used to identify reported cases of the tumour. Results. Microscopic features of the tumour include: (i Conspicuous intracellular and intercellular lumina/microcysts encompassed by malignant urothelial or squamous cells. (ii The lumina are usually empty; may contain granular eosinophilic debris, mucin, or necrotic cells. (iii The cysts may be variable in size; round, or oval, up to 2 mm; lined by urothelium which are either flattened cells or low columnar cells however, they do not contain colonic epithelium or goblet cells; are infiltrative; invade the muscularis propria; mimic cystitis cystica and cystitis glandularis; occasionally exhibit neuroendocrine differentiation. (iv Elongated and irregular branching spaces are usually seen. About 17 cases of the tumour have been reported with only 2 patients who have survived. The tumour tends to be of high-grade and high-stage. There is no consensus opinion on the best option of treatment of the tumour. Conclusions. It would prove difficult at the moment to be dogmatic regarding its prognosis but it is a highly aggressive tumour. New cases of the tumour should be reported in order to document its biological behaviour.

  18. Characterization of form variants of Xenorhabdus luminescens.

    Science.gov (United States)

    Gerritsen, L J; de Raay, G; Smits, P H

    1992-01-01

    From Xenorhabdus luminescens XE-87.3 four variants were isolated. One, which produced a red pigment and antibiotics, was luminescent, and could take up dye from culture media, was considered the primary form (XE-red). A pink-pigmented variant (XE-pink) differed from the primary form only in pigmentation and uptake of dye. Of the two other variants, one produced a yellow pigment and fewer antibiotics (XE-yellow), while the other did not produce a pigment or antibiotics (XE-white). Both were less luminescent, did not take up dye, and had small cell and colony sizes. These two variants were very unstable and shifted to the primary form after 3 to 5 days. It was not possible to separate the primary form and the white variant completely; subcultures of one colony always contained a few colonies of the other variant. The white variant was also found in several other X. luminescens strains. DNA fingerprints showed that all four variants are genetically identical and are therefore derivatives of the same parent. Protein patterns revealed a few differences among the four variants. None of the variants could be considered the secondary form. The pathogenicity of the variants decreased in the following order: XE-red, XE-pink, XE-yellow, and XE-white. The mechanism and function of this variability are discussed. Images PMID:1622273

  19. Molecular models of NS3 protease variants of the Hepatitis C virus

    Directory of Open Access Journals (Sweden)

    Mello Isabel MVGC

    2005-01-01

    Full Text Available Abstract Background Hepatitis C virus (HCV currently infects approximately three percent of the world population. In view of the lack of vaccines against HCV, there is an urgent need for an efficient treatment of the disease by an effective antiviral drug. Rational drug design has not been the primary way for discovering major therapeutics. Nevertheless, there are reports of success in the development of inhibitor using a structure-based approach. One of the possible targets for drug development against HCV is the NS3 protease variants. Based on the three-dimensional structure of these variants we expect to identify new NS3 protease inhibitors. In order to speed up the modeling process all NS3 protease variant models were generated in a Beowulf cluster. The potential of the structural bioinformatics for development of new antiviral drugs is discussed. Results The atomic coordinates of crystallographic structure 1CU1 and 1DY9 were used as starting model for modeling of the NS3 protease variant structures. The NS3 protease variant structures are composed of six subdomains, which occur in sequence along the polypeptide chain. The protease domain exhibits the dual beta-barrel fold that is common among members of the chymotrypsin serine protease family. The helicase domain contains two structurally related beta-alpha-beta subdomains and a third subdomain of seven helices and three short beta strands. The latter domain is usually referred to as the helicase alpha-helical subdomain. The rmsd value of bond lengths and bond angles, the average G-factor and Verify 3D values are presented for NS3 protease variant structures. Conclusions This project increases the certainty that homology modeling is an useful tool in structural biology and that it can be very valuable in annotating genome sequence information and contributing to structural and functional genomics from virus. The structural models will be used to guide future efforts in the structure

  20. Membrane fractions active in poliovirus RNA replication contain VPg precursor polypeptides

    International Nuclear Information System (INIS)

    Takegami, T.; Semler, B.L.; Anderson, C.W.; Wimmer, E.

    1983-01-01

    The poliovirus specific polypeptide P3-9 is of special interest for studies of viral RNA replication because it contains a hydrophobic region and, separated by only seven amino acids from that region, the amino acid sequence of the genome-linked protein VPg. Membraneous complexes of poliovirus-infected HeLa cells that contain poliovirus RNA replicating proteins have been analyzed for the presence of P3-9 by immunoprecipitation. Incubation of a membrane fraction rich in P3-9 with proteinase leaves the C-terminal 69 amino acids of P3-9 intact, an observation suggesting that this portion is protected by its association with the cellular membrane. These studies have also revealed two hitherto undescribed viral polypeptides consisting of amino acid sequences of the P2 andf P3 regions of the polyprotein. Sequence analysis by stepwise Edman degradation show that these proteins are 3b/9 (M/sub r/77,000) and X/9 (M/sub r/50,000). 3b/9 and X/9 are membrane bound and are turned over rapidly and may be direct precursors to proteins P2-X and P3-9 of the RNA replication complex. P2-X, a polypeptide void of hydrophobic amino acid sequences but also found associated with membranes, is rapidly degraded when the membraneous complex is treated with trypsin. It is speculated that P2-X is associated with membranes by its affinity to the N-terminus of P3-9

  1. Injectable, Biomolecule-Responsive Polypeptide Hydrogels for Cell Encapsulation and Facile Cell Recovery through Triggered Degradation.

    Science.gov (United States)

    Xu, Qinghua; He, Chaoliang; Zhang, Zhen; Ren, Kaixuan; Chen, Xuesi

    2016-11-16

    Injectable hydrogels have been widely investigated in biomedical applications, and increasing demand has been proposed to achieve dynamic regulation of physiological properties of hydrogels. Herein, a new type of injectable and biomolecule-responsive hydrogel based on poly(l-glutamic acid) (PLG) grafted with disulfide bond-modified phloretic acid (denoted as PLG-g-CPA) was developed. The hydrogels formed in situ via enzymatic cross-linking under physiological conditions in the presence of horseradish peroxidase and hydrogen peroxide. The physiochemical properties of the hydrogels, including gelation time and the rheological property, were measured. Particularly, the triggered degradation of the hydrogel in response to a reductive biomolecule, glutathione (GSH), was investigated in detail. The mechanical strength and inner porous structure of the hydrogel were influenced by the addition of GSH. The polypeptide hydrogel was used as a three-dimensional (3D) platform for cell encapsulation, which could release the cells through triggered disruption of the hydrogel in response to the addition of GSH. The cells released from the hydrogel were found to maintain high viability. Moreover, after subcutaneous injection into rats, the PLG-g-CPA hydrogels with disulfide-containing cross-links exhibited a markedly faster degradation behavior in vivo compared to that of the PLG hydrogels without disulfide cross-links, implying an interesting accelerated degradation process of the disulfide-containing polypeptide hydrogels in the physiological environment in vivo. Overall, the injectable and biomolecule-responsive polypeptide hydrogels may serve as a potential platform for 3D cell culture and easy cell collection.

  2. The generalized model of polypeptide chain describing the helix-coil transition in biopolymers

    International Nuclear Information System (INIS)

    Mamasakhlisov, E.S.; Badasyan, A.V.; Tsarukyan, A.V.; Grigoryan, A.V.; Morozov, V.F.

    2005-07-01

    In this paper we summarize some results of our theoretical investigations of helix-coil transition both in single-strand (polypeptides) and two-strand (polynucleotides) macromolecules. The Hamiltonian of the Generalized Model of Polypeptide Chain (GMPC) is introduced to describe the system in which the conformations are correlated over some dimensional range Δ (it equals 3 for polypeptide, because one H-bond fixes three pairs of rotation, for double strand DNA it equals to one chain rigidity because of impossibility of loop formation on the scale less than Δ). The Hamiltonian does not contain any parameter designed especially for helix-coil transition and uses pure molecular microscopic parameters (the energy of hydrogen bond formation, reduced partition function of repeated unit, the number of repeated units fixed by one hydrogen bond, the energies of interaction between the repeated units and the solvent molecules). To calculate averages we evaluate the partition function using the transfer-matrix approach. The GMPC allowed to describe the influence of a number of factors, affecting the transition, basing on a unified microscopic approach. Thus we obtained, that solvents change transition temperature and interval in different ways, depending on type of solvent and on energy of solvent- macromolecule interaction; stacking on the background of H-bonding increases stability and decreases cooperativity of melting. For heterogeneous DNA we could analytically derive well known formulae for transition temperature and interval. In the framework of GMPC we calculate and show the difference of two order parameters of helix-coil transition - the helicity degree, and the average fraction of repeated units in helical conformation. Given article has the aim to review the results obtained during twenty years in the context of GMPC. (author)

  3. A multiscale model to evaluate the efficacy of anticancer therapies based on chimeric polypeptide nanoparticles

    Science.gov (United States)

    Paiva, L. R.; Martins, M. L.

    2011-01-01

    A multiscale model for tumor growth and its chemotherapy using conjugate nanoparticles is presented, and the corresponding therapeutic outcomes are evaluated. It is found that doxorubicin assembled into chimeric polypeptide nanoparticles cannot eradicate either vascularized primary tumors or avascular micrometastasis even administrated at loads close to their maximum tolerated doses. Furthermore, an effective and safety treatment demands for conjugate nanoparticles targeted to the malignant cells with much higher specificity and affinity than those currently observed in order to leave most of the normal tissues unaffected and to ensure a fast intracellular drug accumulation.

  4. Zwitterionic states in gas-phase polypeptide ions revealed by 157-nm ultra-violet photodissociation

    DEFF Research Database (Denmark)

    Kjeldsen, Frank; Silivra, Oleg A; Zubarev, Roman A

    2006-01-01

    carboxylic groups relative to competing COOH losses (45 Da) from neutral carboxylic groups. Loss of CO2 is a strong indication of the presence of a zwitterionic [(+)...(-)...(+)] salt bridge in the gas-phase polypeptide cation. This method provides a tool for studying, for example, the nature of binding...... of the fragment formation should be taken into account. Cations of Trp-cage proteins exist preferentially as zwitterions, with the deprotonation position divided between the Asp9 residue and the C terminus in the ratio 3:2. The majority of dications of the same molecule are not zwitterions. Furthermore, 157-nm...

  5. Tuning Thermoresponsive Properties of Cationic Elastin-like Polypeptides by Varying Counterions and Side-Chains.

    Science.gov (United States)

    Petitdemange, Rosine; Garanger, Elisabeth; Bataille, Laure; Bathany, Katell; Garbay, Bertrand; Deming, Timothy J; Lecommandoux, Sébastien

    2017-05-17

    We report the synthesis of methionine-containing recombinant elastin-like polypeptides (ELPs) of different lengths that contain periodically spaced methionine residues. These ELPs were chemoselectively alkylated at all methionine residues to give polycationic derivatives. Some of these samples were found to possess solubility transitions in water, where the temperature of these transitions varied with ELP concentration, nature of the methionine alkylating group, and nature of the sulfonium counterions. These studies show that introduction and controlled spacing of methionine sulfonium residues into ELPs can be used as a means both to tune their solubility transition temperatures in water using a variety of different parameters and to introduce new side-chain functionality.

  6. Vasoactive intestinal polypeptide (VIP) in cirrhosis: arteriovenous extraction in different vascular beds

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Staun-Olsen, P; Fahrenkrug, J

    1980-01-01

    The concentration of vasoactive intestinal polypeptide (VIP) was determined in peripheral venous plasma from 136 patients with liver cirrhosis without gastrointestinal bleeding or coma and from 112 controls. In eight patients (cirrhosis, six; fibrosis, one; steatosis, one) arteriovenous extraction...... is significantly elevated in peripheral plasma from patients with cirrhosis, probably due to porto-systemic shunting and/or compromised hepatic elimination. Hepatic elimination is still likely to account for the inactivation of most of the VIP escaping from the neurosynapses throughout the body in patients...

  7. Pituitary adenylate cyclase-activating polypeptide: occurrence and relaxant effect in female genital tract

    DEFF Research Database (Denmark)

    Steenstrup, B R; Alm, P; Hannibal, J

    1995-01-01

    The distribution, localization, and smooth muscle effects of pituitary adenylate cyclase-activating polypeptide (PACAP) were studied in the human female genital tract. The concentrations of PACAP-38 and PACAP-27 were measured by radioimmunoassays, and both peptides were found throughout the genital...... was observed. The findings suggest a smooth muscle regulatory role of PACAP in the human female reproductive tract....... tract. The highest concentrations of PACAP-38 were detected in the ovary, the upper part of vagina, and the perineum. The concentrations of PACAP-27 were generally low, in some regions below the detection limit and in other regions 1 to 5% of the PACAP-38 concentrations. Immunocytochemistry revealed...

  8. Impaired pancreatic polypeptide response to a meal in type 1 diabetic patients

    DEFF Research Database (Denmark)

    Rasmussen, M H; Carstensen, H; List, S

    1993-01-01

    The pancreatic polypeptide (PP) response to a mixed meal was investigated in seven insulin-dependent diabetics without measurable signs of diabetic autonomic neuropathy, and in seven healthy subjects. Since acute changes in metabolic regulation might influence the meal-induced PP response...... is independent of short-term changes in metabolic control. Since the response was attenuated in the insulin-dependent diabetic patients, who had no otherwise measurable signs of neuropathy, the PP response to a meal could be a sensitive indicator of dysfunction of the reflex arc controlling PP secretion...

  9. A new splice variant of the major subunit of human asialoglycoprotein receptor encodes a secreted form in hepatocytes.

    Directory of Open Access Journals (Sweden)

    Jia Liu

    Full Text Available BACKGROUND: The human asialoglycoprotein receptor (ASGPR is composed of two polypeptides, designated H1 and H2. While variants of H2 have been known for decades, the existence of H1 variants has never been reported. PRINCIPAL FINDINGS: We identified two splice variants of ASGPR H1 transcripts, designated H1a and H1b, in human liver tissues and hepatoma cells. Molecular cloning of ASGPR H1 variants revealed that they differ by a 117 nucleotide segment corresponding to exon 2 in the ASGPR genomic sequence. Thus, ASGPR variant H1b transcript encodes a protein lacking the transmembrane domain. Using an H1b-specific antibody, H1b protein and a functional soluble ASGPR (sASGPR composed of H1b and H2 in human sera and in hepatoma cell culture supernatant were identified. The expression of ASGPR H1a and H1b in Hela cells demonstrated the different cellular loctions of H1a and H1b proteins at cellular membranes and in intracellular compartments, respectively. In vitro binding assays using fluorescence-labeled sASGPR or the substract ASOR revealed that the presence of sASGPR reduced the binding of ASOR to cells. However, ASOR itself was able to enhance the binding of sASGPR to cells expressing membrane-bound ASGPR. Further, H1b expression is reduced in liver tissues from patients with viral hepatitis. CONCLUSIONS: We conclude that two naturally occurring ASGPR H1 splice variants are produced in human hepatocytes. A hetero-oligomeric complex sASGPR consists of the secreted form of H1 and H2 and may bind to free substrates in circulation and carry them to liver tissue for uptake by ASGPR-expressing hepatocytes.

  10. In vitro and in vivo phosphorylation of polypeptides in plasma membrane and tonoplast-enriched fractions from barley roots

    International Nuclear Information System (INIS)

    Garbarino, J.E.; Hurkman, W.J.; Tanaka, C.K.; DuPont, F.M.

    1991-01-01

    Phosphorylation of polypeptides in membrane fractions from barley (Hordeum vulgare L. cv CM 72) roots was compared in in vitro and in vivo assays to assess the potential role of protein kinases in modification of membrane transport. Membrane fractions enriched in endoplasmic reticulum, tonoplast, and plasma membrane were isolated using sucrose gradients and the membrane polypeptides separated using sodium dodecyl sulfate polyacrylamide gel electrophoresis. When the membrane fractions were incubated with γ[p 32 P]ATP, phosphorylation occurred almost exclusively in the plasma membrane fraction. Phosphorylation of a band at 38 kilodaltons increased as the concentration of Mg 2+ was decreased from millimolar to micromolar levels. Phosphorylation of bands at 125, 86, 58, 46 and 28 kilodaltons required millimolar Mg 2+ concentrations and was greatly enhanced by Ca 2+ . When roots of intact plants were labeled with [ 32 P]orthophosphate, polypeptides at approximately 135, 166, 90, 46 to 53, 32, 28, and 19 kilodaltons were labeled in the plasma membrane fraction and polypeptides at approximately 73, 66, and 48 kilodaltons were labeled in the tonoplast fraction. Treatment of the roots of intact plants with 150 millimolar NaCl resulted in increased phosphorylation of some polypeptides while treatment with 100 mM NaCl had no effect

  11. Molecular diversity and hypoglycemic polypeptide-P content of Momordica charantia in different accessions and different seasons.

    Science.gov (United States)

    Tian, Miao; Zeng, Xiang-Qing; Song, Huan-Lei; Hu, Shan-Xin; Wang, Fu-Jun; Zhao, Jian; Hu, Zhi-Bi

    2015-04-01

    Momordica charantia (MC) has been used for treating diabetes mellitus from ancient times in Asia, Africa and South America. There are many MC accessions in local markets. Polypeptide-P as a main hypoglycemic component in MC was first studied in this experiment to illustrate the different contents in MC of different accessions and different harvesting times. Nineteen MC accessions collected from different regions were clustered into three groups using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) molecular markers. Content of polypeptide-P in the tested MC accessions was detected by western blot (WB) method. The WB results revealed that polypeptide-P was detected in MC accessions harvested in June and July but not in September and October. Furthermore, Polypeptide-P content corresponded well with the MC accessions. Our results suggest that the MC accessions and the harvesting times or the weather during harvest play significant roles in high content of polypeptide-P. © 2014 Society of Chemical Industry.

  12. Shift-Variant Multidimensional Systems.

    Science.gov (United States)

    1985-05-29

    x,y;u,v) is the system response at (x,y) to an unit impulse applied at (u,v). The presence of additive noise in the preceding input-output model of a...space model developed works very effi- ciently to deblur images affected by 2-D linear shift- varying blurs, its use, in presence of noise needs to be...causal linear shift-variant (LSV) system, whose impulse res- ponse is a K-th order degenerate sequence, a K-th order state-space model was obtained

  13. Peptides, polypeptides and peptide-polymer hybrids as nucleic acid carriers.

    Science.gov (United States)

    Ahmed, Marya

    2017-10-24

    Cell penetrating peptides (CPPs), and protein transduction domains (PTDs) of viruses and other natural proteins serve as a template for the development of efficient peptide based gene delivery vectors. PTDs are sequences of acidic or basic amphipathic amino acids, with superior membrane trespassing efficacies. Gene delivery vectors derived from these natural, cationic and cationic amphipathic peptides, however, offer little flexibility in tailoring the physicochemical properties of single chain peptide based systems. Owing to significant advances in the field of peptide chemistry, synthetic mimics of natural peptides are often prepared and have been evaluated for their gene expression, as a function of amino acid functionalities, architecture and net cationic content of peptide chains. Moreover, chimeric single polypeptide chains are prepared by a combination of multiple small natural or synthetic peptides, which imparts distinct physiological properties to peptide based gene delivery therapeutics. In order to obtain multivalency and improve the gene delivery efficacies of low molecular weight cationic peptides, bioactive peptides are often incorporated into a polymeric architecture to obtain novel 'polymer-peptide hybrids' with improved gene delivery efficacies. Peptide modified polymers prepared by physical or chemical modifications exhibit enhanced endosomal escape, stimuli responsive degradation and targeting efficacies, as a function of physicochemical and biological activities of peptides attached onto a polymeric scaffold. The focus of this review is to provide comprehensive and step-wise progress in major natural and synthetic peptides, chimeric polypeptides, and peptide-polymer hybrids for nucleic acid delivery applications.

  14. Temperature-dependent morphology of hybrid nanoflowers from elastin-like polypeptides

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Koushik; Balog, Eva Rose M.; Sista, Prakash; Williams, Darrick J.; Martinez, Jennifer S., E-mail: jenm@lanl.gov, E-mail: rcrocha@lanl.gov; Rocha, Reginaldo C., E-mail: jenm@lanl.gov, E-mail: rcrocha@lanl.gov [Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kelly, Daniel [Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-02-01

    We report a method for creating hybrid organic-inorganic “nanoflowers” using calcium or copper ions as the inorganic component and a recombinantly expressed elastin-like polypeptide (ELP) as the organic component. Polypeptides provide binding sites for the dynamic coordination with metal ions, and then such noncovalent complexes become nucleation sites for primary crystals of metal phosphates. We have shown that the interaction between the stimuli-responsive ELP and Ca{sup 2+} or Cu{sup 2+}, in the presence of phosphate, leads to the growth of micrometer-sized particles featuring nanoscale patterns shaped like flower petals. The morphology of these flower-like composite structures is dependent upon the temperature of growth and has been characterized by scanning electron microscopy. The composition of nanoflowers has also been analyzed by energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The temperature-dependent morphologies of these hybrid nanostructures, which arise from the controllable phase transition of ELPs, hold potential for morphological control of biomaterials in emerging applications such as tissue engineering and biocatalysis.

  15. Temperature-dependent morphology of hybrid nanoflowers from elastin-like polypeptides

    Directory of Open Access Journals (Sweden)

    Koushik Ghosh

    2014-02-01

    Full Text Available We report a method for creating hybrid organic-inorganic “nanoflowers” using calcium or copper ions as the inorganic component and a recombinantly expressed elastin-like polypeptide (ELP as the organic component. Polypeptides provide binding sites for the dynamic coordination with metal ions, and then such noncovalent complexes become nucleation sites for primary crystals of metal phosphates. We have shown that the interaction between the stimuli-responsive ELP and Ca2+ or Cu2+, in the presence of phosphate, leads to the growth of micrometer-sized particles featuring nanoscale patterns shaped like flower petals. The morphology of these flower-like composite structures is dependent upon the temperature of growth and has been characterized by scanning electron microscopy. The composition of nanoflowers has also been analyzed by energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The temperature-dependent morphologies of these hybrid nanostructures, which arise from the controllable phase transition of ELPs, hold potential for morphological control of biomaterials in emerging applications such as tissue engineering and biocatalysis.

  16. Elastin-like polypeptides: the power of design for smart cell encapsulation.

    Science.gov (United States)

    Bandiera, Antonella

    2017-01-01

    Cell encapsulation technology is still a challenging issue. Innovative methodologies such as additive manufacturing, and alternative bioprocesses, such as cell therapeutic delivery, where cell encapsulation is a key tool are rapidly gaining importance for their potential in regenerative medicine. Responsive materials such as elastin-based recombinant expression products have features that are particularly attractive for cell encapsulation. They can be designed and tailored to meet desired requirements. Thus, they represent promising candidates for the development of new concept-based materials that can be employed in this field. Areas covered: An overview of the design and employment of elastin-like polypeptides for cell encapsulation is given to outline the state of the art. Special attention is paid to the design of the macromolecule employed as well as to the method of matrix formation and the biological system involved. Expert opinion: As a result of recent progress in regenerative medicine there is a compelling need for materials that provide specific properties and demonstrate defined functional features. Rationally designed materials that may adapt according to applied external stimuli and that are responsive to biological systems, such as elastin-like polypeptides, belong to this class of smart material. A run through the components described to date represents a good starting point for further advancement in this area. Employment of these components in cell encapsulation application will promote its advance toward 'smart cell encapsulation technology'.

  17. Toughening of Thermoresponsive Arrested Networks of Elastin-Like Polypeptides To Engineer Cytocompatible Tissue Scaffolds.

    Science.gov (United States)

    Glassman, Matthew J; Avery, Reginald K; Khademhosseini, Ali; Olsen, Bradley D

    2016-02-08

    Formulation of tissue engineering or regenerative scaffolds from simple bioactive polymers with tunable structure and mechanics is crucial for the regeneration of complex tissues, and hydrogels from recombinant proteins, such as elastin-like polypeptides (ELPs), are promising platforms to support these applications. The arrested phase separation of ELPs has been shown to yield remarkably stiff, biocontinuous, nanostructured networks, but these gels are limited in applications by their relatively brittle nature. Here, a gel-forming ELP is chain-extended by telechelic oxidative coupling, forming extensible, tough hydrogels. Small angle scattering indicates that the chain-extended polypeptides form a fractal network of nanoscale aggregates over a broad concentration range, accessing moduli ranging from 5 kPa to over 1 MPa over a concentration range of 5-30 wt %. These networks exhibited excellent erosion resistance and allowed for the diffusion and release of encapsulated particles consistent with a bicontinuous, porous structure with a broad distribution of pore sizes. Biofunctionalized, toughened networks were found to maintain the viability of human mesenchymal stem cells (hMSCs) in 2D, demonstrating signs of osteogenesis even in cell media without osteogenic molecules. Furthermore, chondrocytes could be readily mixed into these gels via thermoresponsive assembly and remained viable in extended culture. These studies demonstrate the ability to engineer ELP-based arrested physical networks on the molecular level to form reinforced, cytocompatible hydrogel matrices, supporting the promise of these new materials as candidates for the engineering and regeneration of stiff tissues.

  18. UDP-[14C]glucose-labelable polypeptides from pea: Possible components of glucan synthase I activity

    International Nuclear Information System (INIS)

    Ray, P.M.; Dhugga, K.S.; Gallaghar, S.R.

    1989-01-01

    A membrane-bound polypeptide doublet of about 40 kD can be rapidly labeled with UDP-[ 14 C]glucose under the assay conditions for glucan synthase I (GS-I). Label seems covalently bound, and chases when unlabeled UDPG is added; it might represent a covalent intermediate in polysaccharide synthesis. Labeling and GS-I activity show several common features: they co-sediment with Golgi membranes in sucrose gradients; they depend similarly on Mg 2+ or Mn 2+ (not Ca 2+ ); they decrease dramatically from stem apex to base, and are higher in epidermis than internal tissue; they show similar sensitivities to several inhibitors. But the doublet still labels after polysaccharide-synthesizing activity has been destroyed by Triton X-100. The doublet polypeptides might be glucosyl tranferases whose ability to transfer glucose units to a glucan chain is detergent-sensitive, but to accept glucose from UDPG is not; or they might be detergent-insensitive primary glucose acceptors, from which a distinct, detergent-sensitive transferase(s) move(s) these units to glucan chains

  19. Analysis of Urine Composition in Type II Diabetic Mice after Intervention Therapy Using Holothurian Polypeptides

    Directory of Open Access Journals (Sweden)

    Yanyan Li

    2017-07-01

    Full Text Available Hydrolysates and peptide fractions (PF obtained from sea cucumber with commercial enzyme were studied on the hyperglycemic and renal protective effects on db/db rats using urine metabolomics. Compared with the control group the polypeptides from the two species could significantly reduce the urine glucose and urea. We also tried to address the compositions of highly expressed urinary proteins using a proteomics approach. They were serum albumins, AMBP proteins, negative trypsin, elastase, and urinary protein, GAPDH, a receptor of urokinase-type plasminogen activator (uPAR, and Ig kappa chain C region. We used the electronic nose to quickly detect changes in the volatile substances in mice urine after holothurian polypeptides (HPP fed, and the results show it can identify the difference between treatment groups with the control group without overlapping. The protein express mechanism of HPP treating diabetes was discussed, and we suggested these two peptides with the hypoglycemic and renal protective activity might be utilized as nutraceuticals.

  20. cDNA encoding a polypeptide including a hev ein sequence

    Energy Technology Data Exchange (ETDEWEB)

    Raikhel, Natasha V. (Okemos, MI); Broekaert, Willem F. (Dilbeek, BE); Chua, Nam-Hai (Scarsdale, NY); Kush, Anil (New York, NY)

    2000-07-04

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  1. Biomimetic Synthesis of Gelatin Polypeptide-Assisted Noble-Metal Nanoparticles and Their Interaction Study

    Science.gov (United States)

    Liu, Ying; Liu, Xiaoheng; Wang, Xin

    2011-12-01

    Herein, the generation of gold, silver, and silver-gold (Ag-Au) bimetallic nanoparticles was carried out in collagen (gelatin) solution. It first showed that the major ingredient in gelatin polypeptide, glutamic acid, acted as reducing agent to biomimetically synthesize noble metal nanoparticles at 80°C. The size of nanoparticles can be controlled not only by the mass ratio of gelatin to gold ion but also by pH of gelatin solution. Interaction between noble-metal nanoparticles and polypeptide has been investigated by TEM, UV-visible, fluorescence spectroscopy, and HNMR. This study testified that the degradation of gelatin protein could not alter the morphology of nanoparticles, but it made nanoparticles aggregated clusters array (opposing three-dimensional α-helix folding structure) into isolated nanoparticles stabilized by gelatin residues. This is a promising merit of gelatin to apply in the synthesis of nanoparticles. Therefore, gelatin protein is an excellent template for biomimetic synthesis of noble metal/bimetallic nanoparticle growth to form nanometer-sized device.

  2. High-resolution polypeptide structure and dynamics in anisotropic environments: The gramicidin channel

    Energy Technology Data Exchange (ETDEWEB)

    Cross, T.A.; Lee, K.C.; Ketchem, R.R.; Hu, W.; Lazo, N.D.; Huo, S. [Florida State Univ., Tallahassee, FL (United States)

    1994-12-01

    To understand the details of macromolecular function, high-resolution structural and dynamic detail is essential. The polypeptide fold of the gramicidin channel has been effectively modeled for the past 20 years, yet the functional changes in conductance and channel lifetime associated with amino acid substitutions cannot be predicted. To accomplish this goal, high-resolution electrostatic modeling and the precise orientation of all dipoles are required. Furthermore, an enhanced knowledge of the complex molecular environment of this membrane-bound peptide is needed. An aqueous environment is relatively uniform and achiral. The membrane environment is very heterogenous and chiral. A knowledge of the interactions, specific and nonspecific, between peptide and lipid will aid in developing a better understanding of this environment. To accomplish this goal, it is necessary to study the peptide in an extended lipid bilayer, rather than in a vesicular or micellar form. These latter environments are likely to possess increased dynamics, increased water penetration, and distorted interactions between the polypeptide and membrane surface. To perform NMR studies on bilayer bound peptides, solid state NMR methods are required, and for specific site information, isotopic labels are incorporated using solid phase peptide synthesis.

  3. Primary structure of pancreatic polypeptide from four species of Perissodactyla (Przewalski's horse, zebra, rhino, tapir).

    Science.gov (United States)

    Henry, J S; Lance, V A; Conlon, J M

    1991-12-01

    Pancreatic polypeptide (PP) has been purified from extracts of the pancreas of four species of odd-toed ungulates (Perissodactyla): Przewalski's horse, mountain zebra, white rhinoceros, and mountain tapir. The amino acid sequence of Przewalski's horse pancreatic polypeptide was established as Ala-Pro-Met-Glu-Pro-Val-Tyr-Pro-Gly-Asp10-Asn- Ala-Thr-Pro-Glu-Gln-Met-Ala-Gln-Tyr20-Ala-Ala-Glu-Leu-Arg-Arg-Tyr- Ile-Asn-Met30 - Leu-Thr-Arg-Pro-Arg-Tyr.NH2. Zebra PP was identical to Przewalski's horse PP, rhinoceros PP contained three substitutions relative to the horse (Ser for Ala1, Leu for Met3, and Glu for Gln16), and tapir PP contained one substitution relative to the horse (Leu for Met3). On the basis of morphological characteristics and the fossil record, the rhinocerotids are classified with the tapirids in the suborder Ceratomorpha, whereas the horse and zebra belong to a separate suborder, Hippomorpha. On the basis of structural similarity of the PP molecules, however, it would appear that the tapir is more closely related to the horse than to the rhinoceros. These observations provide a further example of the need for extreme caution when inferring taxonomic or phylogenetic relationships between species from the structures of homologous peptides.

  4. Amphotericin B-conjugated polypeptide hydrogels as a novel innovative strategy for fungal infections

    Science.gov (United States)

    Shu, Chang; Li, Tengfei; Yang, Wen; Li, Duo; Ji, Shunli; Ding, Li

    2018-03-01

    The present work is focused on the design and development of novel amphotericin B (AmB)-conjugated biocompatible and biodegradable polypeptide hydrogels to improve the antifungal activity. Using three kinds of promoting self-assembly groups (2-naphthalene acetic acid (Nap), naproxen (Npx) and dexamethasone (Dex)) and polypeptide sequence (Phe-Phe-Asp-Lys-Tyr, FFDKY), we successfully synthesized the Nap-FFDK(AmB)Y gels, Npx-FFDK(AmB)Y gels and Dex-FFDK(AmB)Y gels. The AmB-conjugated hydrogelators are highly soluble in different aqueous solutions. The cryo-transmission electron microscopy and scanning electron microscopy micrographs of hydrogels afford nanofibres with a width of 20-50 nm. Powder X-ray diffraction analyses demonstrate that the crystalline structures of the AmB and Dex are changed into amorphous structures after the formation of hydrogels. Circular dichroism spectra of the solution of blank carriers and the corresponding drug deliveries further help elucidate the molecular arrangement in gel phase, indicating the existence of turn features. The in vitro drug releases suggest that the AmB-conjugated hydrogels are suitable as drug-controlled release vehicles for hydrophobic drugs. The antifungal effect of AmB-conjugated hydrogels significantly exhibits the antifungal activity against Candida albicans. The results of the present study indicated that the AmB-conjugated hydrogels are suitable carriers for poorly water soluble drugs and for enhancement of therapeutic efficacy of antifungal drugs.

  5. Specific photoaffinity labeling of two plasma membrane polypeptides with an azido auxin

    International Nuclear Information System (INIS)

    Hicks, G.R.; Rayle, D.L.; Jones, A.M.; Lomax, T.L.

    1989-01-01

    Plasma membrane vesicles were isolated from zucchini (Cucurbita pepo) hypocotyl tissue by aqueous phase partitioning and assessed for homogeneity by the use of membrane-specific enzyme assays. The highly pure plasma membrane vesicles maintained a pH differential across the membrane and accumulated a tritiated azido analogue of 3-indoleacetic acid (IAA), 5-azido-[7- 3 H]IAA([ 3 H]N 3 IAA), in a manner similar to the accumulation of [ 3 H]IAA. The association of the [ 3 H]N 3 IAA with membrane vesicles was saturable and subject to competition by IAA and auxin analogues. Auxin-binding proteins were photoaffinity labeled by addition of [ 3 H]N 3 IAA to plasma membrane vesicles prior to exposure to UV light and detected by subsequent NaDodSO 4 /PAGE and fluorography. When the reaction temperature was lowered to -196 degree C, high-specific-activity labeling of a 40-kDa and a 42-kDa polypeptide was observed. Collectively, these results suggest that the radiolabeled polypeptides are auxin receptors. The covalent nature of the label should facilitate purification and further characterization of the receptors

  6. Glucose-dependent insulinotropic polypeptide (GIP) receptor deletion leads to reduced bone strength and quality.

    Science.gov (United States)

    Mieczkowska, Aleksandra; Irwin, Nigel; Flatt, Peter R; Chappard, Daniel; Mabilleau, Guillaume

    2013-10-01

    Bone is permanently remodeled by a complex network of local, hormonal and neuronal factors that affect osteoclast and osteoblast biology. In this context, a role for gastro-intestinal hormones has been proposed based on evidence that bone resorption dramatically falls after a meal. Glucose-dependent insulinotropic polypeptide (GIP) is one of the candidate hormones as its receptor, glucose-dependent insulinotropic polypeptide receptor (GIPR), is expressed in bone. In the present study we investigated bone strength and quality by three-point bending, quantitative x-ray microradiography, microCT, qBEI and FTIR in a GIPR knockout (GIPR KO) mouse model and compared with control wild-type (WT) animals. Animals with a deletion of the GIPR presented with a significant reduction in ultimate load (--11%), stiffness (-16%), total absorbed (-28%) and post-yield energies (-27%) as compared with WT animals. Furthermore, despite no change in bone outer diameter, the bone marrow diameter was significantly increased and as a result cortical thickness was significantly decreased by 20% in GIPR deficient animals. Bone resorption at the endosteal surface was significantly increased whilst bone formation was unchanged in GIPR deficient animals. Deficient animals also presented with a pronounced reduction in the degree of mineralization of bone matrix. Furthermore, the amount of mature cross-links of collagen matrix was significantly reduced in GIPR deficient animals and was associated with lowered intrinsic material properties. Taken together, these data support a positive effect of the GIPR on bone strength and quality. © 2013.

  7. Architecture effects on multivalent interactions by polypeptide-based multivalent ligands

    Science.gov (United States)

    Liu, Shuang

    protein materials, including structural as well as functional proteins. Therefore, polypeptide-based multivalent scaffolds are used to display ligands to assess the contribution of different architectural parameters to the multivalent binding events. In this work, a family of alanine-rich alpha-helical glycopolypeptides was designed and synthesized by a combination of protein engineering and chemical coupling, to display two types of saccharide ligands for two different multivalent binding systems. The valencies, chain length and spacing between adjacent ligands of these multivalent ligands were designed in order to study architecture effects on multivalent interactions. The polypeptides and their glycoconjugates were characterized via various methods, including SDS-PAGE, NMR, HPLC, amino acid analysis (AAA), MALDI, circular dichroism (CD) and GPC. In the first multivalent binding system, cholera toxin B pentamer (CT B5) was chosen to be the protein receptor due to its well-characterized structure, lack of significant steric interference of binding to multiple binding sites, and requirement of only simple monosaccharide as ligands. Galactopyranoside was incorporated into polypeptide scaffolds through amine-carboxylic acid coupling to the side chains of glutamic acid residues. The inhibition and binding to CT B5 of these glycopolypeptide ligands were evaluated by direct enzyme-linked assay (DELA). As a complement method, weak affinity chromatography (WAC) was also used to evaluate glycopolypeptides binding to a CT B5 immobilized column. The architecture effects on CT B 5 inhibition are discussed. In the second system, cell surface receptor L-selectin was targeted by polypeptide-based multivalent ligands containing disulfated galactopyranoside ligands, due to its important roles in various immunological activities. The effects of glycopolypeptide architectural variables L-selectin shedding were evaluated via ELISA-based assays. These polypeptide-based multivalent ligands

  8. A Novel Insertion Variant of CRYGD Is Associated with Congenital Nuclear Cataract in a Chinese Family.

    Science.gov (United States)

    Zhuang, Xiaotong; Wang, Lianqing; Song, Zixun; Xiao, Wei

    2015-01-01

    To investigate a novel insertion variant of CRYGD identified in a Chinese family with nuclear congenital cataract. A Chinese family with congenital nuclear cataract was recruited for the mutational screening of candidate genes by direct sequencing. Recombinant N-terminal Myc tagged wildtype or mutant CRYGD was expressed in HEK293T cells. The expression pattern, protein solubility and subcellular distribution were analyzed by western blotting and immunofluorescence. A novel insertion variant, c.451_452insGACT, in CRYGD was identified in the patients. It causes a frameshift and a premature termination of the polypeptide to become Y151*. A significantly reduced solubility was observed for this mutant. Unlike wildtype CRYGD, which existed mainly in the cytoplasm, Y151* was mis-located in the nucleus. We have identified a novel mutation, c.451_452insGACT, in CRYGD, which is associated with nuclear cataract. This is the first insertion mutation of CRYGD found to cause autosomal dominant congenital cataract. The mutant protein, with loss of solubility and localization to the nucleus, is hypothesized to be the major cause of cataract in these patients.

  9. Formation of a [sup(99m)Tc]polypeptide hormone: characterization and chemical quality control by ampholyte displacement radiochromatography

    International Nuclear Information System (INIS)

    Sundrehagen, E.

    1983-01-01

    Sup(99m)Tc-complexes with the polypeptide hormone secretin in very low concentration were formed by the concentrated hydrochloric acid/vacuum evaporation/gentisic acid method. The sup(99m)Tc-secretin was characterized by a modified ampholyte radiochromatographic procedure, in addition to thin layer chromatography, gel chromatography and paper electrophoresis. High radiochemical purity and specific radioactivity were obtained. In vivo distribution studies were performed, and the conditions necessary for application of [sup(99m)Tc]polypeptides as scintigraphic agents are discussed. (author)

  10. 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

  11. Developing consistent pronunciation models for phonemic variants

    CSIR Research Space (South Africa)

    Davel, M

    2006-09-01

    Full Text Available Pronunciation lexicons often contain pronunciation variants. This can create two problems: It can be difficult to define these variants in an internally consistent way and it can also be difficult to extract generalised grapheme-to-phoneme rule sets...

  12. Semantic prioritization of novel causative genomic variants

    KAUST Repository

    Boudellioua, Imene

    2017-04-17

    Discriminating the causative disease variant(s) for individuals with inherited or de novo mutations presents one of the main challenges faced by the clinical genetics community today. Computational approaches for variant prioritization include machine learning methods utilizing a large number of features, including molecular information, interaction networks, or phenotypes. Here, we demonstrate the PhenomeNET Variant Predictor (PVP) system that exploits semantic technologies and automated reasoning over genotype-phenotype relations to filter and prioritize variants in whole exome and whole genome sequencing datasets. We demonstrate the performance of PVP in identifying causative variants on a large number of synthetic whole exome and whole genome sequences, covering a wide range of diseases and syndromes. In a retrospective study, we further illustrate the application of PVP for the interpretation of whole exome sequencing data in patients suffering from congenital hypothyroidism. We find that PVP accurately identifies causative variants in whole exome and whole genome sequencing datasets and provides a powerful resource for the discovery of causal variants.

  13. Semantic prioritization of novel causative genomic variants

    KAUST Repository

    Boudellioua, Imene; Mohamad Razali, Rozaimi; Kulmanov, Maxat; Hashish, Yasmeen; Bajic, Vladimir B.; Goncalves-Serra, Eva; Schoenmakers, Nadia; Gkoutos, Georgios V.; Schofield, Paul N.; Hoehndorf, Robert

    2017-01-01

    Discriminating the causative disease variant(s) for individuals with inherited or de novo mutations presents one of the main challenges faced by the clinical genetics community today. Computational approaches for variant prioritization include machine learning methods utilizing a large number of features, including molecular information, interaction networks, or phenotypes. Here, we demonstrate the PhenomeNET Variant Predictor (PVP) system that exploits semantic technologies and automated reasoning over genotype-phenotype relations to filter and prioritize variants in whole exome and whole genome sequencing datasets. We demonstrate the performance of PVP in identifying causative variants on a large number of synthetic whole exome and whole genome sequences, covering a wide range of diseases and syndromes. In a retrospective study, we further illustrate the application of PVP for the interpretation of whole exome sequencing data in patients suffering from congenital hypothyroidism. We find that PVP accurately identifies causative variants in whole exome and whole genome sequencing datasets and provides a powerful resource for the discovery of causal variants.

  14. Fundamental Characteristics of Industrial Variant Specification Systems

    DEFF Research Database (Denmark)

    Hansen, Benjamin Loer; Hvam, Lars

    2004-01-01

    fundamental concepts related to this task, which are relevant to understand for academia and practitioners working with the subject. This is done through a description of variant specification tasks and typical aspects of system solutions. To support the description of variant specification tasks and systems...

  15. Characterization of form variants of Xenorhabdus luminescens.

    NARCIS (Netherlands)

    Gerritsen, L.J.M.; Raay, de G.; Smits, P.H.

    1992-01-01

    From Xenorhabdus luminescens XE-87.3 four variants were isolated. One, which produced a red pigment and antibiotics, was luminescent, and could take up dye from culture media, was considered the primary form (XE-red). A pink-pigmented variant (XE-pink) differed from the primary form only in

  16. CLEVER: Clique-Enumerating Variant Finder

    NARCIS (Netherlands)

    Marschall, T.; Costa, I.; Canzar, S.; bauer, m; Klau, G.W.; Schliep, A.; Schönhuth, A.

    2012-01-01

    Motivation: Next-generation sequencing techniques have facilitated a large-scale analysis of human genetic variation. Despite the advances in sequencing speed, the computational discovery of structural variants is not yet standard. It is likely that many variants have remained undiscovered in most

  17. An engineered polypeptide around nano-sized manganese-calcium oxide: copying plants for water oxidation.

    Science.gov (United States)

    Najafpour, Mohammad Mahdi; Ghobadi, Mohadeseh Zarei; Sarvi, Bahram; Haghighi, Behzad

    2015-09-14

    Synthesis of new efficient catalysts inspired by Nature is a key goal in the production of clean fuel. Different compounds based on manganese oxide have been investigated in order to find their water-oxidation activity. Herein, we introduce a novel engineered polypeptide containing tyrosine around nano-sized manganese-calcium oxide, which was shown to be a highly active catalyst toward water oxidation at low overpotential (240 mV), with high turnover frequency of 1.5 × 10(-2) s(-1) at pH = 6.3 in the Mn(III)/Mn(IV) oxidation range. The compound is a novel structural and efficient functional model for the water-oxidizing complex in Photosystem II. A new proposed clever strategy used by Nature in water oxidation is also discussed. The new model of the water-oxidizing complex opens a new perspective for synthesis of efficient water-oxidation catalysts.

  18. Practical multipeptide synthesis: dedicated software for the definition of multiple, overlapping peptides covering polypeptide sequences.

    Science.gov (United States)

    Heegaard, P M; Holm, A; Hagerup, M

    1993-01-01

    A personal computer program for the conversion of linear amino acid sequences to multiple, small, overlapping peptide sequences has been developed. Peptide lengths and "jumps" (the distance between two consecutive overlapping peptides) are defined by the user. To facilitate the use of the program for parallel solid-phase chemical peptide syntheses for the synchronous production of multiple peptides, amino acids at each acylation step are laid out by the program in a convenient standard multi-well setup. Also, the total number of equivalents, as well as the derived amount in milligrams (depend-ending on user-defined equivalent weights and molar surplus), of each amino acid are given. The program facilitates the implementation of multipeptide synthesis, e.g., for the elucidation of polypeptide structure-function relationships, and greatly reduces the risk of introducing mistakes at the planning step. It is written in Pascal and runs on any DOS-based personal computer. No special graphic display is needed.

  19. Islet amyloid polypeptide and high hydrostatic pressure: towards an understanding of the fibrillization process

    Science.gov (United States)

    Lopes, D. H. J.; Smirnovas, V.; Winter, R.

    2008-07-01

    Type II Diabetes Mellitus is a disease which is characterized by peripheral insulin resistance coupled with a progressive loss of insulin secretion that is associated with a decrease in pancreatic islet β-cell mass and the deposition of amyloid in the extracellular matrix of β-cells, which lead to islet cell death. The principal component of the islet amyloid is a pancreatic hormone called islet amyloid polypeptide (IAPP). High-pressure coupled with FT-IR, CD, ThT fluorescence spectroscopic and AFM studies were carried out to reveal information on the aggregation pathway as well as the aggregate structure of IAPP. Our data indicate that IAPP pre-formed fibrils exhibit a strong polymorphism with heterogeneous structures very sensitive to high hydrostatic pressure, indicating a high percentage of ionic and hydrophobic interactions being responsible for the stability the IAPP fibrils.

  20. The 75-kilodalton cytoplasmic Chlamydia trachomatis L2 polypeptide is a DnaK-like protein

    DEFF Research Database (Denmark)

    Birkelund, Svend; Lundemose, AG; Christiansen, Gunna

    1990-01-01

    ,980-base-pair open reading frame revealed 94% homology with a 75-kilodalton protein from C. trachomatis serovar D and 57% homology with the DnaK proteins of E. coli and of Bacillus megaterium, while amino acid homology with human heat shock protein 70 (hsp70) was 42%. The promoter region was identified......The gene coding for the 75-kilodalton cytoplasmic Chlamydia trachomatis L2 polypeptide has been cloned in Escherichia coli, and the nucleotide sequence has been determined. The cloned DNA fragment contained the coding region as well as the putative promoter. The deduced amino acid sequence of the 1...... by computer search and by primer extension of mRNA synthesized in recombinant E. coli. The promoter region which differed from the putative promoter region in serovar D was shown to be a mixed promoter type in which the -10 region showed a regular TATA box configuration while the -35 region showed high...

  1. l-Cystine-Crosslinked Polypeptide Nanogel as a Reduction-Responsive Excipient for Prostate Cancer Chemotherapy

    Directory of Open Access Journals (Sweden)

    Liang He

    2016-01-01

    Full Text Available Smart polymer nanogel-assisted drug delivery systems have attracted more and more attention in cancer chemotherapy because of their well-defined morphologies and pleiotropic functions in recent years. In this work, an l-cystine-crosslinked reduction-responsive polypeptide nanogel of methoxy poly(ethylene glycol-poly(l-phenylalanine-co-l-cystine (mPEG-P(LP-co-LC was employed as a smart excipient for RM-1 prostate cancer (PCa chemotherapy. Doxorubicin (DOX, as a regular chemotherapy drug, was embedded in the nanogel. The loading nanogel marked as NG/DOX was shown to exhibit glutathione (GSH-induced swelling and GSH-accelerated DOX release. Subsequently, NG/DOX showed efficient cellular uptake and proliferation inhibition. Furthermore, NG/DOX presented enhanced antitumor efficacy and security in an RM-1 PCa-grafted mouse model in vivo, indicating its great potential for clinical treatment.

  2. Protein Complexation and pH Dependent Release Using Boronic Acid Containing PEG-Polypeptide Copolymers.

    Science.gov (United States)

    Negri, Graciela E; Deming, Timothy J

    2017-01-01

    New poly(L-lysine)-b-poly(ethylene glycol) copolypeptides have been prepared, where the side-chain amine groups of lysine residues are modified to contain ortho-amine substituted phenylboronic acid, i.e., Wulff-type phenylboronic acid (WBA), groups to improve their pH responsive, carbohydrate binding properties. These block copolymers form nanoscale complexes with glycosylated proteins that are stable at physiological pH, yet dissociate and release the glycoproteins under acidic conditions, similar to those found in endosomal and lysosomal compartments within cells. These results suggest that WBA modified polypeptide copolymers are promising for further development as degradable carriers for intracellular protein delivery. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Development of the kits for RIA simultaneous determination of polypeptide hormones

    International Nuclear Information System (INIS)

    Szybinski, Z.

    1982-12-01

    A simple and universal modification of chloramine T technique has been developed for the radioactive iodination of several polypeptide hormones such as insulin, human growth hormone (HGH), human TSH, synthetic human gastrin and beta-endorphine. The prepared products proved to have good immunoreactivity suitable for RIA purposes. The technique is inexpensive and quick. A new procedure has also been worked out utilizing horse myeloperoxidase in solid state as catalyser. The hormones iodinated with this technique show better parameters (e.g. longer stability, better binding to antibody, more favourable adsorption on dextran-coated charcoal); however the specific activities achieved were lower. The possibilities of simultaneous measurement of insulin and HGH have been studied. In this connection, a comparatively simple method for the determination of the endogenous anti-insulin antibodies was developed and used for the control of patients with diabetes and for the checking of new insulin preparations. However, the technique requires relatively sophisticated equipment and computerized calculations

  4. Pancreatic polypeptide is involved in the regulation of body weight in pima Indian male subjects

    DEFF Research Database (Denmark)

    Koska, Juraj; DelParigi, Angelo; de Courten, Barbora

    2004-01-01

    Pancreatic polypeptide (PP) is released from the pancreas in response to a meal. In humans, low-circulating PP levels have been observed in obesity, and administration of pharmacological doses of PP has been shown to decrease food intake. The aim of the present study was to investigate whether low...... circulating PP is associated with weight gain in Pima Indians. Plasma PP concentrations were measured after an overnight fast and 30 min after a standardized mixed meal in 33 nondiabetic male subjects who had a follow-up visit 4.9 +/- 2.5 years later. Cross-sectionally, fasting and postprandial PP levels were...... negatively associated with body size and adiposity. Prospectively, the change in PP response to the meal was negatively associated with the change in body weight (r = -0.53, P = 0.002). In contrast, a high fasting PP level was positively associated with change in body weight (r = 0.45, P = 0...

  5. Distribution and protective function of pituitary adenylate cyclase-activating polypeptide (PACAP in the retina

    Directory of Open Access Journals (Sweden)

    Tomoya eNakamachi

    2012-11-01

    Full Text Available Pituitary adenylate cyclase-activating polypeptide (PACAP, which is found in 27- or 38-amino acid forms, belongs to the VIP/glucagon/secretin family. PACAP and its three receptor subtypes are expressed in neural tissues, with PACAP known to exert a protective effect against several types of neural damage. The retina is considered to be part of the central nervous system, and retinopathy is a common cause of profound and intractable loss of vision. This review will examine the expression and morphological distribution of PACAP and its receptors in the retina, and will summarize the current state of knowledge regarding the protective effect of PACAP against different kinds of retinal damage, such as that identified in association with diabetes, ultraviolet light, hypoxia, optic nerve transection, and toxins. This article will also address PACAP-mediated protective pathways involving retinal glial cells.

  6. Design of monodisperse and well-defined polypeptide-based polyvalent inhibitors of anthrax toxin.

    Science.gov (United States)

    Patke, Sanket; Boggara, Mohan; Maheshwari, Ronak; Srivastava, Sunit K; Arha, Manish; Douaisi, Marc; Martin, Jacob T; Harvey, Ian B; Brier, Matthew; Rosen, Tania; Mogridge, Jeremy; Kane, Ravi S

    2014-07-28

    The design of polyvalent molecules, presenting multiple copies of a specific ligand, represents a promising strategy to inhibit pathogens and toxins. The ability to control independently the valency and the spacing between ligands would be valuable for elucidating structure-activity relationships and for designing potent polyvalent molecules. To that end, we designed monodisperse polypeptide-based polyvalent inhibitors of anthrax toxin in which multiple copies of an inhibitory toxin-binding peptide were separated by flexible peptide linkers. By tuning the valency and linker length, we designed polyvalent inhibitors that were over four orders of magnitude more potent than the corresponding monovalent ligands. This strategy for the rational design of monodisperse polyvalent molecules may not only be broadly applicable for the inhibition of toxins and pathogens, but also for controlling the nanoscale organization of cellular receptors to regulate signaling and the fate of stem cells. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Thermal Synthesis of Polypeptides from N-Butyloxycarbonyl Oligopeptides Containing Aspartyl Residue at C-Terminus

    Directory of Open Access Journals (Sweden)

    Toratane Munegumi

    2017-01-01

    Full Text Available The thermal reactions of amino acids have been investigated for pure organic synthesis, materials preparation in industry, and prebiotic chemistry. N-t-Butyloxycarbonyl aspartic acid (Boc-Asp releases 2-butene and carbon dioxide upon heating without solvents. The resulting mixture of the free molten aspartic acid was dehydrated to give peptide bonds. This study describes the thermal reactions of N-t-butyloxycarbonyl peptides (Boc-Gly-L-Asp, Boc-L-Ala-L-Asp, Boc-L-Val-L-Asp, and Boc-Gly-Gly-L-Asp having an aspartic residue at the carboxyl terminus. The peptides were deprotected upon heating at a constant temperature between 110 and 170°C for 1 to 24 h to afford polypeptides in which the average molecular weight reached 7800.

  8. Breakout character of islet amyloid polypeptide hydrophobic mutations at the onset of type-2 diabetes

    Science.gov (United States)

    Frigori, Rafael B.

    2014-11-01

    Toxic fibrillar aggregates of islet amyloid polypeptide (IAPP) appear as the physical outcome of a peptidic phase transition signaling the onset of type-2 diabetes mellitus in different mammalian species. In particular, experimentally verified mutations on the amyloidogenic segment 20-29 in humans, cats, and rats are highly correlated with the molecular aggregation propensities. Through a microcanonical analysis of the aggregation of IAPP20 -29 isoforms, we show that a minimalist one-bead hydrophobic-polar continuum model for protein interactions properly quantifies those propensities from free-energy barriers. Our results highlight the central role of sequence-dependent hydrophobic mutations on hot spots for stabilization, and thus for the engineering, of such biological peptides.

  9. NMR structure of the glucose-dependent insulinotropic polypeptide fragment, GIP(1-30)amide

    International Nuclear Information System (INIS)

    Alana, Inigo; Hewage, Chandralal M.; G. Malthouse, J. Paul; Parker, Jeremy C.; Gault, Victor A.; O'Harte, Finbarr P.M.

    2004-01-01

    Glucose-dependent insulinotropic polypeptide is an incretin hormone that stimulates insulin secretion and reduces postprandial glycaemic excursions. The glucose-dependent action of GIP on pancreatic β-cells has attracted attention towards its exploitation as a potential drug for type 2 diabetes. Use of NMR or X-ray crystallography is vital to determine the three-dimensional structure of the peptide. Therefore, to understand the basic structural requirements for the biological activity of GIP, the solution structure of the major biologically active fragment, GIP(1-30)amide, was investigated by proton NMR spectroscopy and molecular modelling. The structure is characterised by a full length α-helical conformation between residues F 6 and A 28 . This structural information could play an important role in the design of therapeutic agents based upon GIP receptor agonists

  10. Probing polypeptide GalNAc-transferase isoform substrate specificities by in vitro analysis

    DEFF Research Database (Denmark)

    Kong, Yun; Joshi, Hiren J; Schjoldager, Katrine Ter-Borch Gram

    2015-01-01

    N-acetylgalactosaminyltransferase (GalNAc)-type (mucin-type) O-glycosylation is an abundant and highly diverse modification of proteins. This type of O-glycosylation is initiated in the Golgi by a large family of up to 20 homologous polypeptide GalNAc-T isoenzymes that transfer GalNAc to Ser, Thr...... and possibly Tyr residues. These GalNAc residues are then further elongated by a large set of glycosyltransferases to build a variety of complex O-glycan structures. What determines O-glycan site occupancy is still poorly understood, although it is clear that the substrate specificities of individual...... isoenzymes and the repertoire of GalNAc-Ts in cells are key parameters. The GalNAc-T isoenzymes are differentially expressed in cells and tissues in principle allowing cells to produce unique O-glycoproteomes dependent on the specific subset of isoforms present. In vitro analysis of acceptor peptide...

  11. Lectin Domains of Polypeptide GalNAc Transferases Exhibit Glycopeptide Binding Specificity

    DEFF Research Database (Denmark)

    Pedersen, Johannes W; Bennett, Eric P; Schjoldager, Katrine T-B G

    2011-01-01

    UDP-GalNAc:polypeptide a-N-acetylgalactosaminyltransferases (GalNAc-Ts) constitute a family of up to 20 transferases that initiate mucin-type O-glycosylation. The transferases are structurally composed of catalytic and lectin domains. Two modes have been identified for the selection...... of glycosylation sites by GalNAc-Ts: confined sequence recognition by the catalytic domain alone, and concerted recognition of acceptor sites and adjacent GalNAc-glycosylated sites by the catalytic and lectin domains, respectively. Thus far, only the catalytic domain has been shown to have peptide sequence...... on sequences of mucins MUC1, MUC2, MUC4, MUC5AC, MUC6, and MUC7 as well as a random glycopeptide bead library, we examined the binding properties of four different lectin domains. The lectin domains of GalNAc-T1, -T2, -T3, and -T4 bound different subsets of small glycopeptides. These results indicate...

  12. Immunohistochemical localization of glucagon and pancreatic polypeptide on rat endocrine pancreas: coexistence in rat islet cells

    Directory of Open Access Journals (Sweden)

    YH Huang

    2009-08-01

    Full Text Available We used immunofluorescence double staining method to investigate the cellular localization of glucagon and pancreatic polypeptide (PP in rat pancreatic islets. The results showed that both A-cells (glucagon-secreting cells and PP-cells (PPsecreting cells were located in the periphery of the islets. However, A-cells and PP-cells had a different regional distribution. Most of A-cells were located in the splenic lobe but a few of them were in the duodenal lobe of the pancreas. In contrast, the majority of PP-cells were found in the duodenal lobe and a few of them were in the splenic lobe of the pancreas. Furthermore, we found that 67.74% A-cells had PP immunoreactivity, 70.92% PP-cells contained glucagon immunoreactivity with immunofluorescence double staining. Our data support the concept of a common precursor stem cell for pancreatic hormone-producing cells.

  13. Variant Review with the Integrative Genomics Viewer.

    Science.gov (United States)

    Robinson, James T; Thorvaldsdóttir, Helga; Wenger, Aaron M; Zehir, Ahmet; Mesirov, Jill P

    2017-11-01

    Manual review of aligned reads for confirmation and interpretation of variant calls is an important step in many variant calling pipelines for next-generation sequencing (NGS) data. Visual inspection can greatly increase the confidence in calls, reduce the risk of false positives, and help characterize complex events. The Integrative Genomics Viewer (IGV) was one of the first tools to provide NGS data visualization, and it currently provides a rich set of tools for inspection, validation, and interpretation of NGS datasets, as well as other types of genomic data. Here, we present a short overview of IGV's variant review features for both single-nucleotide variants and structural variants, with examples from both cancer and germline datasets. IGV is freely available at https://www.igv.org Cancer Res; 77(21); e31-34. ©2017 AACR . ©2017 American Association for Cancer Research.

  14. Local binary patterns new variants and applications

    CERN Document Server

    Jain, Lakhmi; Nanni, Loris; Lumini, Alessandra

    2014-01-01

    This book introduces Local Binary Patterns (LBP), arguably one of the most powerful texture descriptors, and LBP variants. This volume provides the latest reviews of the literature and a presentation of some of the best LBP variants by researchers at the forefront of textual analysis research and research on LBP descriptors and variants. The value of LBP variants is illustrated with reported experiments using many databases representing a diversity of computer vision applications in medicine, biometrics, and other areas. There is also a chapter that provides an excellent theoretical foundation for texture analysis and LBP in particular. A special section focuses on LBP and LBP variants in the area of face recognition, including thermal face recognition. This book will be of value to anyone already in the field as well as to those interested in learning more about this powerful family of texture descriptors.

  15. Congenital anomalies and normal skeletal variants

    International Nuclear Information System (INIS)

    Guebert, G.M.; Yochum, T.R.; Rowe, L.J.

    1987-01-01

    Congenital anomalies and normal skeletal variants are a common occurrence in clinical practice. In this chapter a large number of skeletal anomalies of the spine and pelvis are reviewed. Some of the more common skeletal anomalies of the extremities are also presented. The second section of this chapter deals with normal skeletal variants. Some of these variants may simulate certain disease processes. In some instances there are no clear-cut distinctions between skeletal variants and anomalies; therefore, there may be some overlap of material. The congenital anomalies are presented initially with accompanying text, photos, and references, beginning with the skull and proceeding caudally through the spine to then include the pelvis and extremities. The normal skeletal variants section is presented in an anatomical atlas format without text or references

  16. Thermally Targeted Delivery of a c-Myc Inhibitory Peptide In Vivo Using Elastin-like Polypeptide

    Science.gov (United States)

    2009-10-01

    cytoplasm. Also, in a subset of cells, Bac-ELP1⁎-H1 showed very bright nuclear staining exclusive of nucleoli (Fig. 5, lower right, arrows). 3.6. Time...localization was very bright relative to the amount of polypeptide in the cytoplasm, and it appeared to be nucleoplasmic and excluded from nucleoli . The

  17. In vivo guided vascular regeneration with a non-porous elastin-like polypeptide hydrogel tubular scaffold.

    Science.gov (United States)

    Mahara, Atsushi; Kiick, Kristi L; Yamaoka, Tetsuji

    2017-06-01

    Herein, we demonstrate a new approach for small-caliber vascular reconstruction using a non-porous elastin-like polypeptide hydrogel tubular scaffold, based on the concept of guided vascular regeneration (GVR). The scaffolds are composed of elastin-like polypeptide, (Val-Pro-Gly-Ile-Gly) n , for compliance matching and antithrombogenicity and an Arg-Gly-Asp (RGD) motif for connective tissue regeneration. When the polypeptide was mixed with an aqueous solution of β-[Tris(hydroxymethyl)phosphino]propionic acid at 37°C, the polypeptide hydrogel was rapidly formed. The elastic modulus of the hydrogel was 4.4 kPa. The hydrogel tubular scaffold was formed in a mold and reinforced with poly(lactic acid) nanofibers. When tubular scaffolds with an inner diameter of 1 mm and length of 5 mm were implanted into rat abdominal aortae, connective tissue grew along the scaffold luminal surface from the flanking native tissues, resulting in new blood vessel tissue with a thickness of 200 μm in 1 month. In contrast, rats implanted with control scaffolds without the RGD motif died. These results indicate that the non-porous hydrogel tubular scaffold containing the RGD motif effectively induced rapid tissue regeneration and that GVR is a promising strategy for the regeneration of small-diameter blood vessels. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1746-1755, 2017. © 2017 Wiley Periodicals, Inc.

  18. Immune-tolerant elastin-like polypeptides (iTEPs) and their application as CTL vaccine carriers.

    Science.gov (United States)

    Cho, S; Dong, S; Parent, K N; Chen, M

    2016-01-01

    Cytotoxic T lymphocyte (CTL) vaccine carriers are known to enhance the efficacy of vaccines, but a search for more effective carriers is warranted. Elastin-like polypeptides (ELPs) have been examined for many medical applications but not as CTL vaccine carriers. We aimed to create immune tolerant ELPs using a new polypeptide engineering practice and create CTL vaccine carriers using the ELPs. Four sets of novel ELPs, termed immune-tolerant elastin-like polypeptide (iTEP) were generated according to the principles dictating humoral immunogenicity of polypeptides and phase transition property of ELPs. The iTEPs were non-immunogenic in mice. Their phase transition feature was confirmed through a turbidity assay. An iTEP nanoparticle (NP) was assembled from an amphiphilic iTEP copolymer plus a CTL peptide vaccine, SIINFEKL. The NP facilitated the presentation of the vaccine by dendritic cells (DCs) and enhanced vaccine-induced CTL responses. A new ELP design and development practice was established. The non-canonical motif and the immune tolerant nature of the iTEPs broaden our insights about ELPs. ELPs, for the first time, were successfully used as carriers for CTL vaccines. It is feasible to concurrently engineer both immune-tolerant and functional peptide materials. ELPs are a promising type of CTL vaccine carriers.

  19. Glucose-dependent insulinotropic polypeptide may enhance fatty acid re-esterification in subcutaneous abdominal adipose tissue in lean humans

    DEFF Research Database (Denmark)

    Asmar, Meena; Simonsen, Lene; Madsbad, Sten

    2010-01-01

    Glucose-dependent insulinotropic polypeptide (GIP) has been implicated in lipid metabolism in animals. In humans, however, there is no clear evidence of GIP effecting lipid metabolism. The present experiments were performed in order to elucidate the effects of GIP on regional adipose tissue metab...

  20. Mathematical Modelling of Glucose-Dependent Insulinotropic Polypeptide and Glucagon-like Peptide-1 following Ingestion of Glucose

    DEFF Research Database (Denmark)

    Røge, Rikke M; Bagger, Jonatan I; Alskär, Oskar

    2017-01-01

    The incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), play an important role in glucose homeostasis by potentiating glucose-induced insulin secretion. Furthermore, GLP-1 has been reported to play a role in glucose homeostasis by inhibiting ...

  1. Tissue polypeptide-specific antigen (TPS) determinations before and during intermittent maximal androgen blockade in patients with metastatic prostatic carcinoma

    NARCIS (Netherlands)

    Kil, P. J. M.; Goldschmidt, H. M. J.; Wieggers, B. J. A.; Kariakine, O. B.; Studer, U. E.; Whelan, P.; Hetherington, J.; de Reijke, Th M.; Hoekstra, J. W.; Collette, L.

    2003-01-01

    To evaluate the prognostic significance of serially measured tissue polypeptide-specific antigen (TPS) levels in patients with metastatic prostatic carcinoma treated with intermittent maximal androgen blockade (MAB). To determine its value with respect to predicting response to treatment and time to

  2. HPLC of the Polypeptides in a Hydrolyzate of Egg-White Lysozyme. An Experiment for the Undergraduate Biochemistry Laboratory.

    Science.gov (United States)

    Richardson, W. S., III; Burns, L.

    1988-01-01

    Describes a simple high-performance liquid chromatography experiment for undergraduate biochemistry laboratories. The experiment illustrates the separation of polypeptides by a step gradient elution using a single pump instrument with no gradient attachments. Discusses instrumentation, analysis, a sample preparation, and results. (CW)

  3. The lectin domain of UDP-N-acetyl-D-galactosamine: polypeptide N-acetylgalactosaminyltransferase-T4 directs its glycopeptide specificities

    DEFF Research Database (Denmark)

    Hassan, H; Reis, C A; Bennett, E P

    2000-01-01

    The initiation step of mucin-type O-glycosylation is controlled by a large family of homologous UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferases (GalNAc-transferases). Differences in kinetic properties, substrate specificities, and expression patterns of these isoenzymes provide for diff...

  4. Polymer-Block-Polypeptides and Polymer-Conjugated Hybrid Materials as Stimuli-Responsive Nanocarriers for Biomedical Applications.

    Science.gov (United States)

    John, Johnson V; Johnson, Renjith P; Heo, Min Seon; Moon, Byeong Kyu; Byeon, Seong Jin; Kim, Il

    2015-01-01

    Stimuli-responsive nanocarriers are a class of soft materials that includes natural polymers, synthetic polymers, and polypeptides. Recently, modern synthesis tools such as atom transfer radical polymerization, reversible addition-fragmentation chain transfer polymerization, nitroxide-mediated radical polymerization, ring-opening polymerization of α-amino acid N-carboxyanhydrides, and various "click" chemistry strategies were simultaneously employed for the design and synthesis of nanosized drug delivery vehicles. Importantly, the research focused on the improvement of the nanocarrier targetability and the site-specific, triggered release of therapeutics with high drug loading efficiency and minimal drug leakage during the delivery to specific targets. In this context, nanocarriers responsive to common stimuli such as pH, temperature, redox potential, light, etc. have been widely used for the controlled delivery of therapeutics to pathological sites. Currently, different synthesis and self-assembly strategies improved the drug loading efficacy and targeted delivery of therapeutic agents to the desired site. In particular, polypeptide-containing hybrid materials have been developed for the controlled delivery of therapeutic agents. Therefore, stimuli-sensitive synthetic polypeptide-based materials have been extensively investigated in recent years. This review focuses on recent advances in the development of polymer-block-polypeptides and polymer-conjugated hybrid materials that have been designed and evaluated for various stimuli-responsive drug and gene delivery applications.

  5. Transgenic rescue of adipocyte glucose-dependent insulinotropic polypeptide receptor expression restores high fat diet-induced body weight gain

    DEFF Research Database (Denmark)

    Ugleholdt, Randi; Pedersen, Jens; Bassi, Maria Rosaria

    2011-01-01

    that was similar between the groups. In contrast, glucose-dependent insulinotropic polypeptide-mediated insulin secretion does not seem to be important for regulation of body weight after high fat feeding. The study supports a role of the adipocyte GIPr in nutrient-dependent regulation of body weight and lean mass...

  6. Discovery of a Mammalian Splice Variant of Myostatin That Stimulates Myogenesis

    Science.gov (United States)

    Jeanplong, Ferenc; Falconer, Shelley J.; Oldham, Jenny M.; Thomas, Mark; Gray, Tarra S.; Hennebry, Alex; Matthews, Kenneth G.; Kemp, Frederick C.; Patel, Ketan; Berry, Carole; Nicholas, Gina; McMahon, Christopher D.

    2013-01-01

    Myostatin plays a fundamental role in regulating the size of skeletal muscles. To date, only a single myostatin gene and no splice variants have been identified in mammals. Here we describe the splicing of a cryptic intron that removes the coding sequence for the receptor binding moiety of sheep myostatin. The deduced polypeptide sequence of the myostatin splice variant (MSV) contains a 256 amino acid N-terminal domain, which is common to myostatin, and a unique C-terminus of 65 amino acids. Western immunoblotting demonstrated that MSV mRNA is translated into protein, which is present in skeletal muscles. To determine the biological role of MSV, we developed an MSV over-expressing C2C12 myoblast line and showed that it proliferated faster than that of the control line in association with an increased abundance of the CDK2/Cyclin E complex in the nucleus. Recombinant protein made for the novel C-terminus of MSV also stimulated myoblast proliferation and bound to myostatin with high affinity as determined by surface plasmon resonance assay. Therefore, we postulated that MSV functions as a binding protein and antagonist of myostatin. Consistent with our postulate, myostatin protein was co-immunoprecipitated from skeletal muscle extracts with an MSV-specific antibody. MSV over-expression in C2C12 myoblasts blocked myostatin-induced Smad2/3-dependent signaling, thereby confirming that MSV antagonizes the canonical myostatin pathway. Furthermore, MSV over-expression increased the abundance of MyoD, Myogenin and MRF4 proteins (Pmyostatin remained unchanged, which suggests that MSV may promote the growth of skeletal muscles. We conclude that MSV represents a unique example of intra-genic regulation in which a splice variant directly antagonizes the biological activity of the canonical gene product. PMID:24312578

  7. eMelanoBase: an online locus-specific variant database for familial melanoma.

    Science.gov (United States)

    Fung, David C Y; Holland, Elizabeth A; Becker, Therese M; Hayward, Nicholas K; Bressac-de Paillerets, Brigitte; Mann, Graham J

    2003-01-01

    A proportion of melanoma-prone individuals in both familial and non-familial contexts has been shown to carry inactivating mutations in either CDKN2A or, rarely, CDK4. CDKN2A is a complex locus that encodes two unrelated proteins from alternately spliced transcripts that are read in different frames. The alpha transcript (exons 1alpha, 2, and 3) produces the p16INK4A cyclin-dependent kinase inhibitor, while the beta transcript (exons 1beta and 2) is translated as p14ARF, a stabilizing factor of p53 levels through binding to MDM2. Mutations in exon 2 can impair both polypeptides and insertions and deletions in exons 1alpha, 1beta, and 2, which can theoretically generate p16INK4A-p14ARF fusion proteins. No online database currently takes into account all the consequences of these genotypes, a situation compounded by some problematic previous annotations of CDKN2A-related sequences and descriptions of their mutations. As an initiative of the international Melanoma Genetics Consortium, we have therefore established a database of germline variants observed in all loci implicated in familial melanoma susceptibility. Such a comprehensive, publicly accessible database is an essential foundation for research on melanoma susceptibility and its clinical application. Our database serves two types of data as defined by HUGO. The core dataset includes the nucleotide variants on the genomic and transcript levels, amino acid variants, and citation. The ancillary dataset includes keyword description of events at the transcription and translation levels and epidemiological data. The application that handles users' queries was designed in the model-view-controller architecture and was implemented in Java. The object-relational database schema was deduced using functional dependency analysis. We hereby present our first functional prototype of eMelanoBase. The service is accessible via the URL www.wmi.usyd.edu.au:8080/melanoma.html. Copyright 2002 Wiley-Liss, Inc.

  8. In vitro gamma irradiation of some purified polypeptide hormones and their biological and radioimmunological activity

    International Nuclear Information System (INIS)

    Hromadova, M.; Macho, L.; Strbak, V.; Vigas, M.; Mikulaj, L.

    1979-01-01

    Some polypeptide hormones (adrenocorticotropin - ACTH, human and bovine growth hormone - GH, human menopausal gonadotropin - HMG, human luteinizing hormone - LH, and bovine thyrotropin - TSH) were irradiated either with 2.5 or 12.5 Mrad (1.1 Mrad/h) or both and their biological activity or immunoreactivity was tested within few days or 3 to 5 months after irradiation. Biological activity of irradiated ACTH (estimation of corticosterone released into medium by incubated adrenals - Saffran and Schally 1955) was not decreased in both time intervals tested. Ten days after irradiation of bovine GH no changes in biological activity (tibia test - Wilhelmi 1973) were found. No decrease of biological activity of irradiated HMG (augmentation of ovarian and uterine weight - Butt 1973) was found 4 months after irradiation and, finaly, no decrease of bovine TSH activity (radioiodine release from prelabelled thyroid in mice - McKenzie 1958) was found 2 to 30 days after irradiation with 2.5 Mrad, while a decrease was observed after 12.5 Mrad. Three to five months after irradiation, however, there was a decrease of biological activity after both doses. The immunological reactivity of irradiated HMG and LH did not differ from that of nonirradiated samples. The same was found with human GH after 2.5 Mrad, while a decrease of reactivity after 12.5 Mrad was detected. It was concluded that, in most of cases, the sterilizing dose of gamma radiation (2.5 Mrad) did not affect the biological activity of polypeptide hormones and that their sensitivity to irradiation appears to differ. (author)

  9. Morphological variation of stimuli-responsive polypeptide at air–water interface

    International Nuclear Information System (INIS)

    Shin, Sungchul; Ahn, Sungmin; Cheng, Jie; Chang, Hyejin; Jung, Dae-Hong; Hyun, Jinho

    2016-01-01

    Graphical abstract: - Highlights: • It is the first report on the interfacial properties of ELP monolayers formed at the air–water interface. • ELP monolayers could be prepared with high stability at the air–water interface. • The compressive behavior of thermo-sensitive ELP monolayers was imaged. • The SERS spectra showed a change in the ELP secondary structure at different preparation conditions. - Abstract: The morphological variation of stimuli-responsive polypeptide molecules at the air–water interface as a function of temperature and compression was described. The surface pressure–area (π–A) isotherms of an elastin-like polypeptide (ELP) monolayer were obtained under variable external conditions, and Langmuir–Blodgett (LB) monolayers were deposited onto a mica substrate for characterization. As the compression of the ELP monolayer increased, the surface pressure increased gradually, indicating that the ELP monolayer could be prepared with high stability at the air–water interface. The temperature in the subphase of the ELP monolayer was critical in the preparation of LB monolayers. The change in temperature induced a shift in the π–A isotherms as well as a change in ELP secondary structures. Surprisingly, the compression of the ELP monolayer influenced the ELP secondary structure due to the reduction in the phase transition temperature with decreasing temperature. The change in the ELP secondary structure formed at the air–water interface was investigated by surface-enhanced Raman scattering. Moreover, the morphology of the ELP monolayer was subsequently imaged using atomic force microscopy. The temperature responsive behavior resulted in changes in surface morphology from relatively flat structures to rugged labyrinth structures, which suggested conformational changes in the ELP monolayers.

  10. Morphological variation of stimuli-responsive polypeptide at air–water interface

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sungchul; Ahn, Sungmin; Cheng, Jie [Department of Biosystems and Biomaterials Science and Engineering, Seoul National University, Seoul 151-921 (Korea, Republic of); Chang, Hyejin; Jung, Dae-Hong [Department of Chemical Education, Seoul National University, Seoul 151-741 (Korea, Republic of); Hyun, Jinho, E-mail: jhyun@snu.ac.kr [Department of Biosystems and Biomaterials Science and Engineering, Seoul National University, Seoul 151-921 (Korea, Republic of); Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of); Center for Food and Bioconvergence, Seoul National University, Seoul 151-921, Republic of Korea. (Korea, Republic of)

    2016-12-01

    Graphical abstract: - Highlights: • It is the first report on the interfacial properties of ELP monolayers formed at the air–water interface. • ELP monolayers could be prepared with high stability at the air–water interface. • The compressive behavior of thermo-sensitive ELP monolayers was imaged. • The SERS spectra showed a change in the ELP secondary structure at different preparation conditions. - Abstract: The morphological variation of stimuli-responsive polypeptide molecules at the air–water interface as a function of temperature and compression was described. The surface pressure–area (π–A) isotherms of an elastin-like polypeptide (ELP) monolayer were obtained under variable external conditions, and Langmuir–Blodgett (LB) monolayers were deposited onto a mica substrate for characterization. As the compression of the ELP monolayer increased, the surface pressure increased gradually, indicating that the ELP monolayer could be prepared with high stability at the air–water interface. The temperature in the subphase of the ELP monolayer was critical in the preparation of LB monolayers. The change in temperature induced a shift in the π–A isotherms as well as a change in ELP secondary structures. Surprisingly, the compression of the ELP monolayer influenced the ELP secondary structure due to the reduction in the phase transition temperature with decreasing temperature. The change in the ELP secondary structure formed at the air–water interface was investigated by surface-enhanced Raman scattering. Moreover, the morphology of the ELP monolayer was subsequently imaged using atomic force microscopy. The temperature responsive behavior resulted in changes in surface morphology from relatively flat structures to rugged labyrinth structures, which suggested conformational changes in the ELP monolayers.

  11. Elastin-like Polypeptide Linkers for Single-Molecule Force Spectroscopy.

    Science.gov (United States)

    Ott, Wolfgang; Jobst, Markus A; Bauer, Magnus S; Durner, Ellis; Milles, Lukas F; Nash, Michael A; Gaub, Hermann E

    2017-06-27

    Single-molecule force spectroscopy (SMFS) is by now well established as a standard technique in biophysics and mechanobiology. In recent years, the technique has benefitted greatly from new approaches to bioconjugation of proteins to surfaces. Indeed, optimized immobilization strategies for biomolecules and refined purification schemes are being steadily adapted and improved, which in turn has enhanced data quality. In many previously reported SMFS studies, poly(ethylene glycol) (PEG) was used to anchor molecules of interest to surfaces and/or cantilever tips. The limitation, however, is that PEG exhibits a well-known trans-trans-gauche to all-trans transition, which results in marked deviation from standard polymer elasticity models such as the worm-like chain, particularly at elevated forces. As a result, the assignment of unfolding events to protein domains based on their corresponding amino acid chain lengths is significantly obscured. Here, we provide a solution to this problem by implementing unstructured elastin-like polypeptides as linkers to replace PEG. We investigate the suitability of tailored elastin-like polypeptides linkers and perform direct comparisons to PEG, focusing on attributes that are critical for single-molecule force experiments such as linker length, monodispersity, and bioorthogonal conjugation tags. Our results demonstrate that by avoiding the ambiguous elastic response of mixed PEG/peptide systems and instead building the molecular mechanical systems with only a single bond type with uniform elastic properties, we improve data quality and facilitate data analysis and interpretation in force spectroscopy experiments. The use of all-peptide linkers allows alternative approaches for precisely defining elastic properties of proteins linked to surfaces.

  12. Zonadhesin D3-Polypeptides Vary among Species but Are Similar in Equus Species Capable of Interbreeding1

    Science.gov (United States)

    Tardif, Steve; Brady, Heidi A.; Breazeale, Kelly R.; Bi, Ming; Thompson, Leslie D.; Bruemmer, Jason E.; Bailey, Laura B.; Hardy, Daniel M.

    2009-01-01

    Zonadhesin is a rapidly evolving protein in the sperm acrosome that confers species specificity to sperm-zona pellucida adhesion. Though structural variation in zonadhesin likely contributes to its species-specific function, the protein has not previously been characterized in organisms capable of interbreeding. Here we compared properties of zonadhesin in several animals, including the horse (Equus caballus), donkey (E. asinus), and Grevy's zebra (E. grevyi) to determine if variation in zonadhesin correlates with ability of gametes to cross-fertilize. Zonadhesin localized to the apical acrosomes of spermatozoa from all three Equus species, similar to its localization in other animals. Likewise, in horse and donkey testis, zonadhesin was detected only in germ cells, first in the acrosomal granule of round spermatids and then in the developing acrosomes of elongating spermatids. Among non-Equus species, D3-domain polypeptides of mature, processed zonadhesin varied markedly in size and detergent solubility. However, zonadhesin D3-domain polypeptides in horse, donkey, and zebra spermatozoa exhibited identical electrophoretic mobility and detergent solubility. Equus zonadhesin D3-polypeptides (p110/p80 doublet) were most similar in size to porcine and bovine zonadhesin D3-polypeptides (p105). Sequence comparisons revealed that the horse zonadhesin precursor's domain content and arrangement are similar to those of zonadhesin from other large animals. Partial sequences of horse and donkey zonadhesin were much more similar to each other (>99% identity) than they were to orthologous sequences of human, pig, rabbit, and mouse zonadhesin (52%–72% identity). We conclude that conservation of zonadhesin D3-polypeptide properties correlates with ability of Equus species to interbreed. PMID:19794156

  13. Quantitative assessments of the distinct contributions of polypeptide backbone amides versus sidechain groups to chain expansion via chemical denaturation

    Science.gov (United States)

    Holehouse, Alex S.; Garai, Kanchan; Lyle, Nicholas; Vitalis, Andreas; Pappu, Rohit V.

    2015-01-01

    In aqueous solutions with high concentrations of chemical denaturants such as urea and guanidinium chloride (GdmCl) proteins expand to populate heterogeneous conformational ensembles. These denaturing environments are thought to be good solvents for generic protein sequences because properties of conformational distributions align with those of canonical random coils. Previous studies showed that water is a poor solvent for polypeptide backbones and therefore backbones form collapsed globular structures in aqueous solvents. Here, we ask if polypeptide backbones can intrinsically undergo the requisite chain expansion in aqueous solutions with high concentrations of urea and GdmCl. We answer this question using a combination of molecular dynamics simulations and fluorescence correlation spectroscopy. We find that the degree of backbone expansion is minimal in aqueous solutions with high concentrations denaturants. Instead, polypeptide backbones sample conformations that are denaturant-specific mixtures of coils and globules, with a persistent preference for globules. Therefore, typical denaturing environments cannot be classified as good solvents for polypeptide backbones. How then do generic protein sequences expand in denaturing environments? To answer this question, we investigated the effects of sidechains using simulations of two archetypal sequences with amino acid compositions that are mixtures of charged, hydrophobic, and polar groups. We find that sidechains lower the effective concentration of backbone amides in water leading to an intrinsic expansion of polypeptide backbones in the absence of denaturants. Additional dilution of the effective concentration of backbone amides is achieved through preferential interactions with denaturants. These effects lead to conformational statistics in denaturing environments that are congruent with those of canonical random coils. Our results highlight the role of sidechain-mediated interactions as determinants of the

  14. Somatic cancer variant curation and harmonization through consensus minimum variant level data

    Directory of Open Access Journals (Sweden)

    Deborah I. Ritter

    2016-11-01

    Full Text Available Abstract Background To truly achieve personalized medicine in oncology, it is critical to catalog and curate cancer sequence variants for their clinical relevance. The Somatic Working Group (WG of the Clinical Genome Resource (ClinGen, in cooperation with ClinVar and multiple cancer variant curation stakeholders, has developed a consensus set of minimal variant level data (MVLD. MVLD is a framework of standardized data elements to curate cancer variants for clinical utility. With implementation of MVLD standards, and in a working partnership with ClinVar, we aim to streamline the somatic variant curation efforts in the community and reduce redundancy and time burden for the interpretation of cancer variants in clinical practice. Methods We developed MVLD through a consensus approach by i reviewing clinical actionability interpretations from institutions participating in the WG, ii conducting extensive literature search of clinical somatic interpretation schemas, and iii survey of cancer variant web portals. A forthcoming guideline on cancer variant interpretation, from the Association of Molecular Pathology (AMP, can be incorporated into MVLD. Results Along with harmonizing standardized terminology for allele interpretive and descriptive fields that are collected by many databases, the MVLD includes unique fields for cancer variants such as Biomarker Class, Therapeutic Context and Effect. In addition, MVLD includes recommendations for controlled semantics and ontologies. The Somatic WG is collaborating with ClinVar to evaluate MVLD use for somatic variant submissions. ClinVar is an open and centralized repository where sequencing laboratories can report summary-level variant data with clinical significance, and ClinVar accepts cancer variant data. Conclusions We expect the use of the MVLD to streamline clinical interpretation of cancer variants, enhance interoperability among multiple redundant curation efforts, and increase submission of

  15. Synthesis of spatially variant lattices.

    Science.gov (United States)

    Rumpf, Raymond C; Pazos, Javier

    2012-07-02

    It is often desired to functionally grade and/or spatially vary a periodic structure like a photonic crystal or metamaterial, yet no general method for doing this has been offered in the literature. A straightforward procedure is described here that allows many properties of the lattice to be spatially varied at the same time while producing a final lattice that is still smooth and continuous. Properties include unit cell orientation, lattice spacing, fill fraction, and more. This adds many degrees of freedom to a design such as spatially varying the orientation to exploit directional phenomena. The method is not a coordinate transformation technique so it can more easily produce complicated and arbitrary spatial variance. To demonstrate, the algorithm is used to synthesize a spatially variant self-collimating photonic crystal to flow a Gaussian beam around a 90° bend. The performance of the structure was confirmed through simulation and it showed virtually no scattering around the bend that would have arisen if the lattice had defects or discontinuities.

  16. Different Variants of Fundamental Portfolio

    Directory of Open Access Journals (Sweden)

    Tarczyński Waldemar

    2014-06-01

    Full Text Available The paper proposes the fundamental portfolio of securities. This portfolio is an alternative for the classic Markowitz model, which combines fundamental analysis with portfolio analysis. The method’s main idea is based on the use of the TMAI1 synthetic measure and, in limiting conditions, the use of risk and the portfolio’s rate of return in the objective function. Different variants of fundamental portfolio have been considered under an empirical study. The effectiveness of the proposed solutions has been related to the classic portfolio constructed with the help of the Markowitz model and the WIG20 market index’s rate of return. All portfolios were constructed with data on rates of return for 2005. Their effectiveness in 2006- 2013 was then evaluated. The studied period comprises the end of the bull market, the 2007-2009 crisis, the 2010 bull market and the 2011 crisis. This allows for the evaluation of the solutions’ flexibility in various extreme situations. For the construction of the fundamental portfolio’s objective function and the TMAI, the study made use of financial and economic data on selected indicators retrieved from Notoria Serwis for 2005.

  17. Revisiting the human polypeptide GalNAc-T1 and T13 paralogs

    DEFF Research Database (Denmark)

    Festari, María Florencia; Trajtenberg, Felipe; Berois, Nora

    2017-01-01

    transcription-polymerase chain reaction analysis of human neuroblastoma cell lines, normal brain and a small panel of neuroblastoma tumors to demonstrate that several splice variants (Ex10b, ΔEx9, ΔEx2-7 and ΔEx6/8-39bpEx9) were highly expressed in tumor cell lines compared with normal brain, although...

  18. An anti-cancer WxxxE-containing azurin polypeptide inhibits Rac1-dependent STAT3 and ERK/GSK-3β signaling in breast cancer cells.

    Science.gov (United States)

    Zhang, Zhe; Luo, Zhiyong; Min, Wenpu; Zhang, Lin; Wu, Yaqun; Hu, Xiaopeng

    2017-06-27

    In our previous study, we characterized a mycoplasmal small GTPase-like polypeptide of 240 amino acids that possesses an N-terminal WVLGE sequence. The N-terminal WVLGE sequence promotes activation of Rac1 and subsequent host cancer cell proliferation. To investigate the function of the WxxxE motif in the interaction with Rac1 and host tumor progression, we synthesized a 35-amino acid WVLGE-containing polypeptide derived from a cell-penetrating peptide derived from the azurin protein. We verified that the WVLGE-containing polypeptide targeted MCF-7 cells rather than MCF-10A cells. However, the WVLGE-containing polypeptide inhibited activation of Rac1 and induced cellular phenotypes that resulted from inhibition of Rac1. In addition, the WVLGE-containing polypeptide down-regulated phosphorylation of the STAT3 and ERK/GSK-3β signaling pathways, and this effect was abolished by either stimulation or inhibition of Rac1 activity. We also found that the WVLGE-containing polypeptide has a Rac1-dependent potential to suppress breast cancer growth in vitro and in vivo. We suggest that by acting as a Rac1 inhibitor, this novel polypeptide may be useful for the treatment of breast cancer.

  19. Ultrasonographic imaging of papillary thyroid carcinoma variants

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jung Hee [Dept. of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2017-04-15

    Ultrasonography (US) is routinely used to evaluate thyroid nodules. The US features of papillary thyroid carcinoma (PTC), the most common thyroid malignancy, include hypoechogenicity, spiculated/microlobulated margins, microcalcifications, and a nonparallel orientation. However, many PTC variants have been identified, some of which differ from the classic type of PTC in terms of biological behavior and clinical outcomes. This review describes the US features and clinical implications of the variants of PTC. With the introduction of active surveillance replacing immediate biopsy or surgical treatment of indolent, small PTCs, an understanding of the US characteristics of PTC variants will facilitate the individualized management of patients with PTC.

  20. RAGE splicing variants in mammals.

    Science.gov (United States)

    Sterenczak, Katharina Anna; Nolte, Ingo; Murua Escobar, Hugo

    2013-01-01

    The receptor for advanced glycation end products (RAGE) is a multiligand receptor of environmental stressors which plays key roles in pathophysiological processes, including immune/inflammatory disorders, Alzheimer's disease, diabetic arteriosclerosis, tumorigenesis, and metastasis. Besides the full-length RAGE protein in humans nearly 20 natural occurring RAGE splicing variants were described on mRNA and protein level. These naturally occurring isoforms are characterized by either N-terminally or C-terminally truncations and are discussed as possible regulators of the full-length RAGE receptor either by competitive ligand binding or by displacing the full-length protein in the membrane. Accordingly, expression deregulations of the naturally occurring isoforms were supposed to have significant effect on RAGE-mediated disorders. Thereby the soluble C-truncated RAGE isoforms present in plasma and tissues are the mostly focused isoforms in research and clinics. Deregulations of the circulating levels of soluble RAGE forms were reported in several RAGE-associated pathological disorders including for example atherosclerosis, diabetes, renal failure, Alzheimer's disease, and several cancer types. Regarding other mammalian species, the canine RAGE gene showed high similarities to the corresponding human structures indicating RAGE to be evolutionary highly conserved between both species. Similar to humans the canine RAGE showed a complex and extensive splicing activity leading to a manifold pattern of RAGE isoforms. Due to the similarities seen in several canine and human diseases-including cancer-comparative structural and functional analyses allow the development of RAGE and ligand-specific therapeutic approaches beneficial for human and veterinary medicine.

  1. Tuning calcium carbonate growth through physical confinement and templating with amyloid-like polypeptide aggregates

    Science.gov (United States)

    Colaco, Martin Francis

    that this methodology does not extend to three-dimensional confined systems, as the water has no method of escape. Through the addition of an insoluble hydroscopic polymer to our microreactors, amorphous calcium carbonate of controllable sizes can be grown. However, crystalline calcium carbonate cannot be grown without some type of templating. Studies of calcium carbonate templating have predominantly been performed on SAMs or in poorly characterized gels or protein films. The use of ordered protein or polypeptide aggregates for templating permits both geometry and charge surface density to be varied. We have studied the kinetics and final morphology of ordered aggregates of poly-L-glutamic acid and a copolymer of glutamic acid and alanine through experiments and simulations. Electrostatics, not structure, of the monomer appeared to be the dominating factor in the aggregation, as pH and salt concentration changes led to dramatic changes in the kinetics. Examining our experimental with existing models provided inconsistent results, so we developed a new model that yielded physically realistic rate constants, while generating better fits with longer lag phases and faster growths. However, despite the similarity of aggregation conditions, the two polypeptides yielded vastly different morphologies, with the PEA forming typical amyloid-like fibrils and PE forming larger, twisted lamellar aggregates. Templating with these aggregates also yielded dramatically different patterns. Polycrystalline rhombohedral calcite with smooth faces and edges grew on PEA fibrils, with minimal templating in evidence. However, on PE, numerous calcite crystals with triangular projections tracked the surface of the aggregate. The PE lamellae are characterized by extensive beta-sheet structure. In this conformation, the glutamic acid spacings on the surface of the aggregates can mimic the spacings of the carboxylates in the calcite lattice. In addition, the high negative charge density on the

  2. Isolation of a variant of Candida albicans.

    Science.gov (United States)

    Buckley, H R; Price, M R; Daneo-Moore, L

    1982-01-01

    During the course of Candida albicans antigen production, a variant of this organism was encountered which did not produce hyphae at 37 degrees C. Presented here are some of the characteristics of this variant. It produces hyphae at 25 degrees C on cornmeal agar and synthetic medium plus N-acetylglucosamine and Tween 80. At 37 degrees C, it does not produce hyphae on these media, although C. albicans normally does produce hyphae under these circumstances. In liquid synthetic medium, this variant does not produce hyphae at 37 degrees C. The variant strain was analyzed for DNA, RNA, protein content, and particle size. After 50 to 70 h in balanced exponential-phase growth, particle size distribution was narrow, and there were no differences in the DNA, RNA, or protein content per particle in the two strains. When balanced exponential-phase cultures were brought into stationary phase, both strains contained the same amount of DNA per cell. Images PMID:6752021

  3. Isolation of a variant of Candida albicans.

    Science.gov (United States)

    Buckley, H R; Price, M R; Daneo-Moore, L

    1982-09-01

    During the course of Candida albicans antigen production, a variant of this organism was encountered which did not produce hyphae at 37 degrees C. Presented here are some of the characteristics of this variant. It produces hyphae at 25 degrees C on cornmeal agar and synthetic medium plus N-acetylglucosamine and Tween 80. At 37 degrees C, it does not produce hyphae on these media, although C. albicans normally does produce hyphae under these circumstances. In liquid synthetic medium, this variant does not produce hyphae at 37 degrees C. The variant strain was analyzed for DNA, RNA, protein content, and particle size. After 50 to 70 h in balanced exponential-phase growth, particle size distribution was narrow, and there were no differences in the DNA, RNA, or protein content per particle in the two strains. When balanced exponential-phase cultures were brought into stationary phase, both strains contained the same amount of DNA per cell.

  4. Genetic variants of ghrelin in metabolic disorders.

    Science.gov (United States)

    Ukkola, Olavi

    2011-11-01

    An increasing understanding of the role of genes in the development of obesity may reveal genetic variants that, in combination with conventional risk factors, may help to predict an individual's risk for developing metabolic disorders. Accumulating evidence indicates that ghrelin plays a role in regulating food intake and energy homeostasis and it is a reasonable candidate gene for obesity-related co-morbidities. In cross-sectional studies low total ghrelin concentrations and some genetic polymorphisms of ghrelin have been associated with obesity-associated diseases. The present review highlights many of the important problems in association studies of genetic variants and complex diseases. It is known that population-specific differences in reported associations exist. We therefore conclude that more studies on variants of ghrelin gene are needed to perform in different populations to get deeper understanding on the relationship of ghrelin gene and its variants to obesity. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. TREM2 Variants in Alzheimer's Disease

    Science.gov (United States)

    Guerreiro, Rita; Wojtas, Aleksandra; Bras, Jose; Carrasquillo, Minerva; Rogaeva, Ekaterina; Majounie, Elisa; Cruchaga, Carlos; Sassi, Celeste; Kauwe, John S.K.; Younkin, Steven; Hazrati, Lilinaz; Collinge, John; Pocock, Jennifer; Lashley, Tammaryn; Williams, Julie; Lambert, Jean-Charles; Amouyel, Philippe; Goate, Alison; Rademakers, Rosa; Morgan, Kevin; Powell, John; St. George-Hyslop, Peter; Singleton, Andrew; Hardy, John

    2013-01-01

    BACKGROUND Homozygous loss-of-function mutations in TREM2, encoding the triggering receptor expressed on myeloid cells 2 protein, have previously been associated with an autosomal recessive form of early-onset dementia. METHODS We used genome, exome, and Sanger sequencing to analyze the genetic variability in TREM2 in a series of 1092 patients with Alzheimer's disease and 1107 controls (the discovery set). We then performed a meta-analysis on imputed data for the TREM2 variant rs75932628 (predicted to cause a R47H substitution) from three genomewide association studies of Alzheimer's disease and tested for the association of the variant with disease. We genotyped the R47H variant in an additional 1887 cases and 4061 controls. We then assayed the expression of TREM2 across different regions of the human brain and identified genes that are differentially expressed in a mouse model of Alzheimer's disease and in control mice. RESULTS We found significantly more variants in exon 2 of TREM2 in patients with Alzheimer's disease than in controls in the discovery set (P = 0.02). There were 22 variant alleles in 1092 patients with Alzheimer's disease and 5 variant alleles in 1107 controls (P<0.001). The most commonly associated variant, rs75932628 (encoding R47H), showed highly significant association with Alzheimer's disease (P<0.001). Meta-analysis of rs75932628 genotypes imputed from genomewide association studies confirmed this association (P = 0.002), as did direct genotyping of an additional series of 1887 patients with Alzheimer's disease and 4061 controls (P<0.001). Trem2 expression differed between control mice and a mouse model of Alzheimer's disease. CONCLUSIONS Heterozygous rare variants in TREM2 are associated with a significant increase in the risk of Alzheimer's disease. (Funded by Alzheimer's Research UK and others.) PMID:23150934

  6. An Investigation of the Polypeptide, Poly - L - Glutamic Acid, Using Neutron Inelastic Scattering

    International Nuclear Information System (INIS)

    Whittemore, W.L.

    1968-01-01

    The polypeptides are synthetic polymers of amino acids with many similarities to natural proteins. In a large number of cases, one of the conformations for both the synthetic and natural proteins is the α - helix. The simplest of the synthetic polymers with no side chains is polyglycine and the simplest of the synthetic polymers with a small side chain (methyl group) is polyalanine. Dispersion curves have been computed by Gupta for both of these polymers. Polyglutamic acid is similar to polyalanine in that the composition of the basic residue and radius of helix is the same. Polyglutamic acid has a more complicated side chain which will contribute a number of additional natural frequencies that are expected to be essentially independent of conformation. On the other hand, the dispersion curves already derived for polyalanine in the α -helix form should be correct in many specific details for polyglutamic acid. An experimental study has been undertaken for polyglutamic acid at room temperature using the techniques of inelastic neutron scattering. In the first measurements, 'cold' neutrons from a reactor were used to investigate the energy level structure up to ≃ 3 kT for both conformations of the polymer. In addition, the scattering of monoenergetic high-energy neutrons ( > 0.15 eV) provided- by an electron Linac was used to study energy levels above 3 kT. These latter measurements permit comparisons to be made between the calculated and measured results for a much larger range of frequencies (and hence permit a check for a larger number of dispersion curves). This extension of the experimental results to higher frequencies has made it possible to check on the earlier assumption that only the lower frequencies are altered when the conformation is changed. This assumption underlies the evaluation of changes in internal energy with conformation from only the 'cold' neutron data, as is done with the present data. An experiment was performed to evaluate the

  7. Bio-inspired synthesis of hybrid silica nanoparticles templated from elastin-like polypeptide micelles

    Science.gov (United States)

    Han, Wei; MacEwan, Sarah R.; Chilkoti, Ashutosh; López, Gabriel P.

    2015-07-01

    The programmed self-assembly of block copolymers into higher order nanoscale structures offers many attractive attributes for the development of new nanomaterials for numerous applications including drug delivery and biosensing. The incorporation of biomimetic silaffin peptides in these block copolymers enables the formation of hybrid organic-inorganic materials, which can potentially enhance the utility and stability of self-assembled nanostructures. We demonstrate the design, synthesis and characterization of amphiphilic elastin-like polypeptide (ELP) diblock copolymers that undergo temperature-triggered self-assembly into well-defined spherical micelles. Genetically encoded incorporation of the silaffin R5 peptide at the hydrophilic terminus of the diblock ELP leads to presentation of the silaffin R5 peptide on the coronae of the micelles, which results in localized condensation of silica and the formation of near-monodisperse, discrete, sub-100 nm diameter hybrid ELP-silica particles. This synthesis method, can be carried out under mild reaction conditions suitable for bioactive materials, and will serve as the basis for the development and application of functional nanomaterials. Beyond silicification, the general strategies described herein may also be adapted for the synthesis of other biohybrid nanomaterials as well.The programmed self-assembly of block copolymers into higher order nanoscale structures offers many attractive attributes for the development of new nanomaterials for numerous applications including drug delivery and biosensing. The incorporation of biomimetic silaffin peptides in these block copolymers enables the formation of hybrid organic-inorganic materials, which can potentially enhance the utility and stability of self-assembled nanostructures. We demonstrate the design, synthesis and characterization of amphiphilic elastin-like polypeptide (ELP) diblock copolymers that undergo temperature-triggered self-assembly into well

  8. DNA-interactive properties of crotamine, a cell-penetrating polypeptide and a potential drug carrier.

    Directory of Open Access Journals (Sweden)

    Pei-Chun Chen

    Full Text Available Crotamine, a 42-residue polypeptide derived from the venom of the South American rattlesnake Crotalus durissus terrificus, has been shown to be a cell-penetrating protein that targets chromosomes, carries plasmid DNA into cells, and shows specificity for actively proliferating cells. Given this potential role as a nucleic acid-delivery vector, we have studied in detail the binding of crotamine to single- and double-stranded DNAs of different lengths and base compositions over a range of ionic conditions. Agarose gel electrophoresis and ultraviolet spectrophotometry analysis indicate that complexes of crotamine with long-chain DNAs readily aggregate and precipitate at low ionic strength. This aggregation, which may be important for cellular uptake of DNA, becomes less likely with shorter chain length. 25-mer oligonucleotides do not show any evidence of such aggregation, permitting the determination of affinities and size via fluorescence quenching experiments. The polypeptide binds non-cooperatively to DNA, covering about 5 nucleotide residues when it binds to single (ss or (ds double stranded molecules. The affinities of the protein for ss- vs. ds-DNA are comparable, and inversely proportional to salt levels. Analysis of the dependence of affinity on [NaCl] indicates that there are a maximum of ∼3 ionic interactions between the protein and DNA, with some of the binding affinity attributable to non-ionic interactions. Inspection of the three-dimensional structure of the protein suggests that residues 31 to 35, Arg-Trp-Arg-Trp-Lys, could serve as a potential DNA-binding site. A hexapeptide containing this sequence displayed a lower DNA binding affinity and salt dependence as compared to the full-length protein, likely indicative of a more suitable 3D structure and the presence of accessory binding sites in the native crotamine. Taken together, the data presented here describing crotamine-DNA interactions may lend support to the design of more

  9. An Investigation of the Polypeptide, Poly - L - Glutamic Acid, Using Neutron Inelastic Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Whittemore, W. L. [Gulf General Atomic Incorporated, San Diego, CA (United States)

    1968-09-15

    The polypeptides are synthetic polymers of amino acids with many similarities to natural proteins. In a large number of cases, one of the conformations for both the synthetic and natural proteins is the {alpha} - helix. The simplest of the synthetic polymers with no side chains is polyglycine and the simplest of the synthetic polymers with a small side chain (methyl group) is polyalanine. Dispersion curves have been computed by Gupta for both of these polymers. Polyglutamic acid is similar to polyalanine in that the composition of the basic residue and radius of helix is the same. Polyglutamic acid has a more complicated side chain which will contribute a number of additional natural frequencies that are expected to be essentially independent of conformation. On the other hand, the dispersion curves already derived for polyalanine in the {alpha} -helix form should be correct in many specific details for polyglutamic acid. An experimental study has been undertaken for polyglutamic acid at room temperature using the techniques of inelastic neutron scattering. In the first measurements, 'cold' neutrons from a reactor were used to investigate the energy level structure up to Asymptotically-Equal-To 3 kT for both conformations of the polymer. In addition, the scattering of monoenergetic high-energy neutrons ( > 0.15 eV) provided- by an electron Linac was used to study energy levels above 3 kT. These latter measurements permit comparisons to be made between the calculated and measured results for a much larger range of frequencies (and hence permit a check for a larger number of dispersion curves). This extension of the experimental results to higher frequencies has made it possible to check on the earlier assumption that only the lower frequencies are altered when the conformation is changed. This assumption underlies the evaluation of changes in internal energy with conformation from only the 'cold' neutron data, as is done with the present data. An experiment was

  10. Conformational energy calculations on polypeptides and proteins: use of a statistical mechanical procedure for evaluating structure and properties.

    Science.gov (United States)

    Scheraga, H A; Paine, G H

    1986-01-01

    We are using a variety of theoretical and computational techniques to study protein structure, protein folding, and higher-order structures. Our earlier work involved treatments of liquid water and aqueous solutions of nonpolar and polar solutes, computations of the stabilities of the fundamental structures of proteins and their packing arrangements, conformations of small cyclic and open-chain peptides, structures of fibrous proteins (collagen), structures of homologous globular proteins, introduction of special procedures as constraints during energy minimization of globular proteins, and structures of enzyme-substrate complexes. Recently, we presented a new methodology for predicting polypeptide structure (described here); the method is based on the calculation of the probable and average conformation of a polypeptide chain by the application of equilibrium statistical mechanics in conjunction with an adaptive, importance sampling Monte Carlo algorithm. As a test, it was applied to Met-enkephalin.

  11. Prevention of adsorption losses during radioimmunoassay of polypeptide hormones: effectiveness of albumins, gelatin, caseins, Tween 20 and plasma

    International Nuclear Information System (INIS)

    Livesey, J.H.; Donald, R.A.

    1982-01-01

    It is well known that polypeptide hormones adsorb to glass and plastic surfaces and that this adsorption may be reduced by adding a relatively large quantity of another protein. Consequently proteins (or sometimes detergents) are added almost universally to peptide hormone radioimmunassays to minimise loss of analyte by adsorption. This study was undertaken because there are few reports of the relative effectiveness of the proteins so used. The results suggest that moderate concentrations of the widely used albumins of Tween 20 do not always adequately prevent the adsorption of hormonal polypeptides to surfaces. Casein and alkali-treated casein appear to be more effective than the adsorption inhibitors in general use in radioimmunoassay for the range of hormones and adsorptive surfaces tested. They were also found to be very effective for preventing the adsorption of radio-labelled human luteinizing hormone, human growth hormone and Tyr-somatostatin. (Auth.)

  12. Prohormone convertase 1/3 is essential for processing of the glucose-dependent insulinotropic polypeptide precursor

    DEFF Research Database (Denmark)

    Ugleholdt, Randi; Poulsen, Marie-Louise H; Holst, Peter J

    2006-01-01

    The physiology of the incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), and their role in type 2 diabetes currently attract great interest. Recently we reported an essential role for prohormone convertase (PC) 1/3 in the cleavage of intesti......The physiology of the incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), and their role in type 2 diabetes currently attract great interest. Recently we reported an essential role for prohormone convertase (PC) 1/3 in the cleavage....../3 is essential and sufficient for the production of the intestinal incretin hormone GIP, whereas PC2, although capable of cleaving proGIP, does not participate in intestinal proGIP processing and is not found in intestinal GIP-expressing cells....

  13. Cell proliferation and migration are modulated by Cdk-1-phosphorylated endothelial-monocyte activating polypeptide II.

    Directory of Open Access Journals (Sweden)

    Margaret A Schwarz

    Full Text Available Endothelial-Monocyte Activating Polypeptide (EMAP II is a secreted protein with well-established anti-angiogenic activities. Intracellular EMAP II expression is increased during fetal development at epithelial/mesenchymal boundaries and in pathophysiologic fibroproliferative cells of bronchopulmonary dysplasia, emphysema, and scar fibroblast tissue following myocardial ischemia. Precise function and regulation of intracellular EMAP II, however, has not been explored to date.Here we show that high intracellular EMAP II suppresses cellular proliferation by slowing progression through the G2M cell cycle transition in epithelium and fibroblast. Furthermore, EMAP II binds to and is phosphorylated by Cdk1, and exhibits nuclear/cytoplasmic partitioning, with only nuclear EMAP II being phosphorylated. We observed that extracellular secreted EMAP II induces endothelial cell apoptosis, where as excess intracellular EMAP II facilitates epithelial and fibroblast cells migration.Our findings suggest that EMAP II has specific intracellular effects, and that this intracellular function appears to antagonize its extracellular anti-angiogenic effects during fetal development and pulmonary disease progression.

  14. A positive 111in-pentetreotide scan in a patient with a pancreatic polypeptide secreting tumour

    International Nuclear Information System (INIS)

    Stanton, K.; Cehic, G.

    2003-01-01

    Full text: A 55-year-old male presented to our department with a known polypeptide secreting pancreatic tumour. An 111 In-pentetreotide scan (OctreoScan) was performed to determine whether the tumour expressed somatostatin receptors (SR) and thereby aid in therapy planning. 120 MBq 111 In-pentetreotide was administered intravenously. Images were acquired at 4 and 30 hours. Whole body images were acquired with spot views and tomography of the liver at 30 hours. Images showed intense uptake of the tracer in the lobular midline pancreatic mass. There was also uptake in multiple liver metastases. 111 In-pentetreotide is a synthetic somatostatin analogue and its uptake demonstrates the presence of SR on tumour cells, especially those of a neuro-endocrine nature. A 123 I Metaiodobenzylguanidine (MIBG) scan was also performed to determine whether the more widely available MIBG therapy would be appropriate for this patient. This scan was negative. The patient has received 3 cycles of chemotherapy with Streptozotocin and 5-fluorouracil. He has had a good partial response to therapy as demonstrated on CT scan. The patient is currently clinically well, his symptoms have resolved and weight stabilised. Good biochemical response to chemotherapy is indicated by halved pancreatic peptide levels. To date chemotherapy has been the mainstay of therapy for neuroendocrine tumours. Radioimmunotherapy (targeted to SR positive tumours) is currently being investigated as a therapy alternative and may be a future treatment option. Copyright (2003) The Australian and New Zealand Society of Nuclear Medicine Inc

  15. Multiscale characterization of a chimeric biomimetic polypeptide for stem cell culture

    International Nuclear Information System (INIS)

    Sbrana, F; Vassalli, M; Fotia, C; Baldini, N; Ciapetti, G; Bracalello, A; Bochicchio, B; Marletta, G

    2012-01-01

    Mesenchymal stem cells have attracted great interest in the field of tissue engineering and regenerative medicine because of their multipotentiality and relative ease of isolation from adult tissues. The medical application of this cellular system requires the inclusion in a growth and delivery scaffold that is crucial for the clinical effectiveness of the therapy. In particular, the ideal scaffolding material should have the needed porosity and mechanical strength to allow a good integration with the surrounding tissues, but it should also assure high biocompatibility and full resorbability. For such a purpose, protein-inspired biomaterials and, in particular, elastomeric-derived polypeptides are playing a major role, in which they are expected to fulfil many of the biological and mechanical requirements. A specific chimeric protein, designed starting from elastin, resilin and collagen sequences, was characterized over different length scales. Single-molecule mechanics, aggregation properties and compatibility with human mesenchymal stem cells were tested, showing that the engineered compound is a good candidate as a stem cell scaffold to be used in tissue engineering applications. (paper)

  16. 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

  17. Functional conservation of the hydrophobic domain of polypeptide 3AB between human rhinovirus and poliovirus

    International Nuclear Information System (INIS)

    Towner, Jonathan S.; Brown, David M.; Nguyen, Joseph H.C.; Semler, Bert L.

    2003-01-01

    In this study we exchanged portions of the poliovirus type 1 (PV1) hydrophobic domain within the membrane-associated polypeptide 3AB for the analogous sequences from human rhinovirus 14 (HRV14). The sequence exchanges were based upon a previous report in which the 22 amino acid hydrophobic region was subdivided into two domains, I and II, the latter of which was shown to be required for membrane association (J. Biol. Chem. 271 (1996), 26810). Using these divisions, the HRV14 sequences were cloned into the complete poliovirus type 1 cDNA sequence. RNAs transcribed from these cDNAs were transfected into HeLa cell monolayers and used in HeLa cell-free translation/replication assays. The data indicated that 3AB sequences from PV1 and HRV14 are interchangeable; however, the substitutions cause a range of significant RNA replication defects, and in some cases, protein processing defects. Following transfection of RNAs encoding the domain substitutions into HeLa cell monolayers, virus isolates were harvested, and the corresponding viral RNAs were sequenced. The sequence data revealed that for the carboxy-terminal domain substitutions (domain II), multiple nucleotide changes were identified in the first, second, and third positions of different codons. In addition, the data indicated that for one of the PV1/HRV14 chimeras to replicate, compensatory mutations within poliovirus protein 2B may be required

  18. Star Polymers Reduce Islet Amyloid Polypeptide Toxicity via Accelerated Amyloid Aggregation.

    Science.gov (United States)

    Pilkington, Emily H; Lai, May; Ge, Xinwei; Stanley, William J; Wang, Bo; Wang, Miaoyi; Kakinen, Aleksandr; Sani, Marc-Antonie; Whittaker, Michael R; Gurzov, Esteban N; Ding, Feng; Quinn, John F; Davis, Thomas P; Ke, Pu Chun

    2017-12-11

    Protein aggregation into amyloid fibrils is a ubiquitous phenomenon across the spectrum of neurodegenerative disorders and type 2 diabetes. A common strategy against amyloidogenesis is to minimize the populations of toxic oligomers and protofibrils by inhibiting protein aggregation with small molecules or nanoparticles. However, melanin synthesis in nature is realized by accelerated protein fibrillation to circumvent accumulation of toxic intermediates. Accordingly, we designed and demonstrated the use of star-shaped poly(2-hydroxyethyl acrylate) (PHEA) nanostructures for promoting aggregation while ameliorating the toxicity of human islet amyloid polypeptide (IAPP), the peptide involved in glycemic control and the pathology of type 2 diabetes. The binding of PHEA elevated the β-sheet content in IAPP aggregates while rendering a new morphology of "stelliform" amyloids originating from the polymers. Atomistic molecular dynamics simulations revealed that the PHEA arms served as rodlike scaffolds for IAPP binding and subsequently accelerated IAPP aggregation by increased local peptide concentration. The tertiary structure of the star nanoparticles was found to be essential for driving the specific interactions required to impel the accelerated IAPP aggregation. This study sheds new light on the structure-toxicity relationship of IAPP and points to the potential of exploiting star polymers as a new class of therapeutic agents against amyloidogenesis.

  19. Pancreatic polypeptide: Identification of target tissues and investigation of possible physiologic significance

    International Nuclear Information System (INIS)

    Shetzline, M.A.

    1988-01-01

    Pancreatic Polypeptide (PP) is a 36 amino acid peptide with hormonal properties but whose physiologic function remains unknown. In order to determine the function of this peptide we investigated potential target tissues using an in vivo radioreceptor assay. In vitro high concentrations of unlabeled hormone competitively inhibit low concentrations of labeled hormone from binding to receptors. Our in vivo studies indicate that, in the presence of concentrated unlabeled peptide, labeled PP distributes between the plasma and interstitial fluid. When saline rather than excess unlabeled PP is injected, the labeled peptide appears to distribute in a volume exceeding the combined plasma and interstitial fluid volume of tissue. The distribution volume which exceeds the anatomic extracellular volume and which is not present with excess unlabeled peptide, is the receptor compartment. With this assay we demonstrated in the rat specific and displaceable PP binding to the ductus choledochus, duodenum, ileum, and adrenal gland. In vitro rat adrenal cell membranes showed specific I-125 labeled PP binding. Specific binding also occurred in bovine cortical and medullary membranes

  20. Intersegment interactions and helix-coil transition within the generalized model of polypeptide chains approach

    Science.gov (United States)

    Badasyan, A. V.; Hayrapetyan, G. N.; Tonoyan, Sh. A.; Mamasakhlisov, Y. Sh.; Benight, A. S.; Morozov, V. F.

    2009-09-01

    The generalized model of polypeptide chains is extended to describe the helix-coil transition in a system comprised of two chains interacting side-by-side. The Hamiltonian of the model takes into account four possible types of interactions between repeated units of the two chains, i.e., helix-helix, helix-coil, coil-helix, and coil-coil. Analysis reveals when the energy Ihh+Icc of (h-h, c-c) interactions overwhelms the energy Ihc+Ich of mixed (h-c, c-h) interactions, the correlation length rises substantially, resulting in narrowing of the transition interval. In the opposite case, when Ihh+Icc

  1. Pancreatic polypeptide controls energy homeostasis via Npy6r signaling in the suprachiasmatic nucleus in mice.

    Science.gov (United States)

    Yulyaningsih, Ernie; Loh, Kim; Lin, Shu; Lau, Jackie; Zhang, Lei; Shi, Yanchuan; Berning, Britt A; Enriquez, Ronaldo; Driessler, Frank; Macia, Laurence; Khor, Ee Cheng; Qi, Yue; Baldock, Paul; Sainsbury, Amanda; Herzog, Herbert

    2014-01-07

    Y-receptors control energy homeostasis, but the role of Npy6 receptors (Npy6r) is largely unknown. Young Npy6r-deficient (Npy6r(-/-)) mice have reduced body weight, lean mass, and adiposity, while older and high-fat-fed Npy6r(-/-) mice have low lean mass with increased adiposity. Npy6r(-/-) mice showed reduced hypothalamic growth hormone releasing hormone (Ghrh) expression and serum insulin-like growth factor-1 (IGF-1) levels relative to WT. This is likely due to impaired vasoactive intestinal peptide (VIP) signaling in the suprachiasmatic nucleus (SCN), where we found Npy6r coexpressed in VIP neurons. Peripheral administration of pancreatic polypeptide (PP) increased Fos expression in the SCN, increased energy expenditure, and reduced food intake in WT, but not Npy6r(-/-), mice. Moreover, intraperitoneal (i.p.) PP injection increased hypothalamic Ghrh mRNA expression and serum IGF-1 levels in WT, but not Npy6r(-/-), mice, an effect blocked by intracerebroventricular (i.c.v.) Vasoactive Intestinal Peptide (VPAC) receptors antagonism. Thus, PP-initiated signaling through Npy6r in VIP neurons regulates the growth hormone axis and body composition. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Interaction between amyloid beta peptide and an aggregation blocker peptide mimicking islet amyloid polypeptide.

    Directory of Open Access Journals (Sweden)

    Nasrollah Rezaei-Ghaleh

    Full Text Available Assembly of amyloid-beta peptide (Aβ into cytotoxic oligomeric and fibrillar aggregates is believed to be a major pathologic event in Alzheimer's disease (AD and interfering with Aβ aggregation is an important strategy in the development of novel therapeutic approaches. Prior studies have shown that the double N-methylated analogue of islet amyloid polypeptide (IAPP IAPP-GI, which is a conformationally constrained IAPP analogue mimicking a non-amyloidogenic IAPP conformation, is capable of blocking cytotoxic self-assembly of Aβ. Here we investigate the interaction of IAPP-GI with Aβ40 and Aβ42 using NMR spectroscopy. The most pronounced NMR chemical shift changes were observed for residues 13-20, while residues 7-9, 15-16 as well as the C-terminal half of Aβ--that is both regions of the Aβ sequence that are converted into β-strands in amyloid fibrils--were less accessible to solvent in the presence of IAPP-GI. At the same time, interaction of IAPP-GI with Aβ resulted in a concentration-dependent co-aggregation of Aβ and IAPP-GI that was enhanced for the more aggregation prone Aβ42 peptide. On the basis of the reduced toxicity of the Aβ peptide in the presence of IAPP-GI, our data are consistent with the suggestion that IAPP-GI redirects Aβ into nontoxic "off-pathway" aggregates.

  3. Elastin-like polypeptide switches: A design strategy to detect multimeric proteins.

    Science.gov (United States)

    Dhandhukia, Jugal P; Brill, Dab A; Kouhi, Aida; Pastuszka, Martha K; MacKay, J Andrew

    2017-09-01

    Elastin-Like Polypeptides (ELPs) reversibly phase separate in response to changes in temperature, pressure, concentration, pH, and ionic species. While powerful triggers, biological microenvironments present a multitude of more specific biological cues, such as antibodies, cytokines, and cell-surface receptors. To develop better biosensors and bioresponsive drug carriers, rational strategies are required to sense and respond to these target proteins. We recently reported that noncovalent association of two ELP fusion proteins to a "chemical inducer of dimerization" small molecule (1.5 kDa) induces phase separation at physiological temperatures. Having detected a small molecule, here we present the first evidence that ELP multimerization can also detect a much larger (60 kDa) protein target. To demonstrate this strategy, ELPs were biotinylated at their amino terminus and mixed with tetrameric streptavidin. At a stoichiometric ratio of [4:1], two to three biotin-ELPs associate with streptavidin into multimeric complexes with an apparent K d of 5 nM. The increased ELP density around a streptavidin core strongly promotes isothermal phase separation, which was tuned to occur at physiological temperature. This phase separation reverses upon saturation with excess streptavidin, which only favors [1:1] complexes. Together, these findings suggest that ELP association with multimeric biomolecules is a viable strategy to deliberately engineer ELPs that respond to multimeric protein substrates. © 2017 The Protein Society.

  4. Double network physical gels from elastin-like polypeptide block copolymers: nanoscale control of thermoresponsive reinforcement

    Science.gov (United States)

    Glassman, Matthew; Olsen, Bradley

    2014-03-01

    Triblock copolymers with associative protein midblocks and thermoresponsive endblocks form shear thinning hydrogels with a low yield stress at low temperatures, but can be reinforced by a self-assembled network of the endblock aggregates. Here, we compare the use of bioengineered elastin-like polypeptides (ELPs) to synthetic poly(N-isopropylacrylamide) (PNIPAM) as endblocks to control the self-assembly of the reinforcing network. The temperature dependence of the mechanics of these hydrogels is a strong function of the domain size and morphology in the endblock network. Despite the architectural similarities, triblock ELP fusions and PNIPAM bioconjugates exhibit distinct reinforcement maxima at fixed block composition and polymer concentration, and these differences can be attributed to the nanostructural features of the two systems. Furthermore, in ELP fusions, the amino acid sequence can be readily modified to manipulate the solvation kinetics of the endblock domains. Finally, various endblocks have been combined to form triblock terpolymer hydrogels, demonstrating how the choice of thermoresponsive blocks can be used to tune the reinforcement of shear thinning hydrogels.

  5. ThPOD3, a truncated polypeptide from Tamarix hispida, conferred drought tolerance in Escherichia coli.

    Science.gov (United States)

    Guo, Xiao-Hong; Jiang, Jing; Wang, Bai-Chen; Li, Hui-Yu; Wang, Yu-Cheng; Yang, Chuan-Ping; Liu, Gui-Feng

    2010-03-01

    The ThPOD1 gene encodes a peroxidase and was isolated from a Tamarix hispida NaCl-stress root cDNA library. We found that ThPOD1 expression could be induced by abiotic stresses such as cold, salt, drought and exogenous abscisic acid. These findings suggested that ThPOD1 might be involved in the plant response to environmental stresses and ABA treatment. To elucidate the function of this gene, recombinant plasmids expressing full-length ThPOD1 as well as ThPOD2 (aa 41-337), and ThPOD3 (aa 73-337) truncated polypeptides were constructed. SDS-PAGE and Western blot analyses of the fusion proteins revealed that the molecular weights of ThPOD1, ThPOD2 and ThPOD3 were approximately 57, approximately 50 and approximately 47 kDa, respectively. Stress assays of E. coli treated with the recombinant plasmids indicated that ThPOD3 could improve resistance to drought stress. This finding could potentially be used to improve plant tolerance to drought stress via gene transfer.

  6. Influence of Aluminium and EGCG on Fibrillation and Aggregation of Human Islet Amyloid Polypeptide

    Directory of Open Access Journals (Sweden)

    Zhi-Xue Xu

    2016-01-01

    Full Text Available The abnormal fibrillation of human islet amyloid polypeptide (hIAPP has been implicated in the development of type II diabetes. Aluminum is known to trigger the structural transformation of many amyloid proteins and induce the formation of toxic aggregate species. The (−-epigallocatechin gallate (EGCG is considered capable of binding both metal ions and amyloid proteins with inhibitory effect on the fibrillation of amyloid proteins. However, the effect of Al(III/EGCG complex on hIAPP fibrillation is unclear. In the present work, we sought to view insight into the structures and properties of Al(III and EGCG complex by using spectroscopic experiments and quantum chemical calculations and also investigated the influence of Al(III and EGCG on hIAPP fibrillation and aggregation as well as their combined interference on this process. Our studies demonstrated that Al(III could promote fibrillation and aggregation of hIAPP, while EGCG could inhibit the fibrillation of hIAPP and lead to the formation of hIAPP amorphous aggregates instead of the ordered fibrils. Furthermore, we proved that the Al(III/EGCG complex in molar ratio of 1 : 1 as Al(EGCG(H2O2 could inhibit the hIAPP fibrillation more effectively than EGCG alone. The results provide the invaluable reference for the new drug development to treat type II diabetes.

  7. β-Hairpin of Islet Amyloid Polypeptide Bound to an Aggregation Inhibitor

    Science.gov (United States)

    Mirecka, Ewa A.; Feuerstein, Sophie; Gremer, Lothar; Schröder, Gunnar F.; Stoldt, Matthias; Willbold, Dieter; Hoyer, Wolfgang

    2016-01-01

    In type 2 diabetes, the formation of islet amyloid consisting of islet amyloid polypeptide (IAPP) is associated with reduction in β-cell mass and contributes to the failure of islet cell transplantation. Rational design of inhibitors of IAPP amyloid formation has therapeutic potential, but is hampered by the lack of structural information on inhibitor complexes of the conformationally flexible, aggregation-prone IAPP. Here we characterize a β-hairpin conformation of IAPP in complex with the engineered binding protein β-wrapin HI18. The β-strands correspond to two amyloidogenic motifs, 12-LANFLVH-18 and 22-NFGAILS-28, which are connected by a turn established around Ser-20. Besides backbone hydrogen bonding, the IAPP:HI18 interaction surface is dominated by non-polar contacts involving hydrophobic side chains of the IAPP β-strands. Apart from monomers, HI18 binds oligomers and fibrils and inhibits IAPP aggregation and toxicity at low substoichiometric concentrations. The IAPP β-hairpin can serve as a molecular recognition motif enabling control of IAPP aggregation. PMID:27641459

  8. Engineered aggregation inhibitor fusion for production of highly amyloidogenic human islet amyloid polypeptide.

    Science.gov (United States)

    Mirecka, Ewa Agnieszka; Gremer, Lothar; Schiefer, Stephanie; Oesterhelt, Filipp; Stoldt, Matthias; Willbold, Dieter; Hoyer, Wolfgang

    2014-12-10

    Human islet amyloid polypeptide (IAPP) is the major component of pancreatic amyloid deposits in type 2 diabetes. The structural conversion of IAPP from a monomeric state into amyloid assemblies is the subject of intense research. Recombinant production of IAPP is, however, difficult due to its extreme aggregation propensity. Here we describe a novel strategy for expression of IAPP in Escherichia coli, based on an engineered protein tag, which sequesters IAPP monomers and prevents IAPP aggregation. The IAPP-binding protein HI18 was selected by phage display from a β-wrapin library. Fusion of HI18 to IAPP enabled the soluble expression of the construct. IAPP was cleaved from the fusion construct and purified to homogeneity with a yield of 3mg of isotopically labeled peptide per liter of culture. In the monomeric state, IAPP was largely disordered as evidenced by far-UV CD and liquid-state NMR spectroscopy but competent to form amyloid fibrils according to atomic force microscopy. These results demonstrate the ability of the engineered β-wrapin HI18 for shielding the hydrophobic sequence of IAPP during expression and purification. Fusion of aggregation-inhibiting β-wrapins is a suitable approach for the recombinant production of aggregation-prone proteins. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Neurofilament heavy polypeptide regulates the Akt-beta-catenin pathway in human esophageal squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Myoung Sook Kim

    2010-02-01

    Full Text Available Aerobic glycolysis and mitochondrial dysfunction are common features of aggressive cancer growth. We observed promoter methylation and loss of expression in neurofilament heavy polypeptide (NEFH in a significant proportion of primary esophageal squamous cell carcinoma (ESCC samples that were of a high tumor grade and advanced stage. RNA interference-mediated knockdown of NEFH accelerated ESCC cell growth in culture and increased tumorigenicity in vivo, whereas forced expression of NEFH significantly inhibited cell growth and colony formation. Loss of NEFH caused up-regulation of pyruvate kinase-M2 type and down-regulation of pyruvate dehydrogenase, via activation of the Akt/beta-catenin pathway, resulting in enhanced aerobic glycolysis and mitochondrial dysfunction. The acceleration of glycolysis and mitochondrial dysfunction in NEFH-knockdown cells was suppressed in the absence of beta-catenin expression, and was decreased by the treatment of 2-Deoxyglucose, a glycolytic inhibitor, or API-2, an Akt inhibitor. Loss of NEFH activates the Akt/beta-catenin pathway and increases glycolysis and mitochondrial dysfunction. Cancer cells with methylated NEFH can be targeted for destruction with specific inhibitors of deregulated downstream pathways.

  10. Distribution of Pancreatic Polypeptide-secreting Endocrine Cells in Nondiabetic and Diabetic Cases.

    Science.gov (United States)

    Śliwińska-Mossoń, Mariola; Milnerowicz, Halina

    2017-07-01

    The aim of the study was to demonstrate the effects of cigarette smoking and ongoing inflammation in chronic pancreatitis on the functioning of pancreatic polypeptide (PP)-secreting cells and to determine the relationship between the occurrence of an increased number of PP cells in the pancreas, the change in their location, and the intensity of their inflammatory changes in the course of pancreatitis and diabetes. Samples of tissues from healthy persons and from patients were verified histopathologically, and then PP was localized by immunohistochemical staining using the monoclonal anti-human PP antibody. The histopathologic evaluation of the hormone expression intensity in tissue sections was carried out using the semiquantitative method and was calculated with digital image analysis. The present study showed a very strong PP expression in the pancreatic tissue (especially in the head of the pancreas) derived from smoking patients with diabetes. The increase in the percentage of cells in the PP islets, between the acinar cells in smoking patients with diabetes and a statistically significant increase in the expression of PP, indicates a pancreatic endocrine dysfunction and suggests that cigarette smoking has a negative impact on the organ's efficiency. Because of its properties, the PP appears to be a useful marker of the endocrine insufficiency of the pancreas and a specific prognostic parameter of developing diabetes due to chronic pancreatitis.

  11. Glucose-Dependent Insulinotropic Polypeptide Mitigates 6-OHDA-Induced Behavioral Impairments in Parkinsonian Rats

    Directory of Open Access Journals (Sweden)

    Yu-Wen Yu

    2018-04-01

    Full Text Available In the present study, the effectiveness of glucose-dependent insulinotropic polypeptide (GIP was evaluated by behavioral tests in 6-hydroxydopamine (6-OHDA hemi-parkinsonian (PD rats. Pharmacokinetic measurements of GIP were carried out at the same dose studied behaviorally, as well as at a lower dose used previously. GIP was delivered by subcutaneous administration (s.c. using implanted ALZET micro-osmotic pumps. After two days of pre-treatment, male Sprague Dawley rats received a single unilateral injection of 6-OHDA into the medial forebrain bundle (MFB. The neuroprotective effects of GIP were evaluated by apomorphine-induced contralateral rotations, as well as by locomotor and anxiety-like behaviors in open-field tests. Concentrations of human active and total GIP were measured in plasma during a five-day treatment period by ELISA and were found to be within a clinically translatable range. GIP pretreatment reduced behavioral abnormalities induced by the unilateral nigrostriatal dopamine (DA lesion produced by 6-OHDA, and thus may be a novel target for PD therapeutic development.

  12. Radioimmunoassay of vasoactive intestinal polypeptide (VIP) in plasma. [/sup 125/I tracer techniques

    Energy Technology Data Exchange (ETDEWEB)

    Fahrenkrug, J.; Schaffalitzky de Muckadell, O.B.

    1977-06-01

    A sensitive and specific radioimmunoassay for vasoactive intestinal polypeptide (VIP) has been developed, which can detect 3.3 pmol x L/sup -1/ of the peptide in plasma. Antisera to highly purified porcine VIP coupled to albumin were raised in eight rabbits. The final dilution, the avidity, and the specificity of each antiserum were determined. /sup 125/I-VIP served as label, and highly purified porcine VIP was used as standard. Separation of antibody-bound and free VIP was achieved by plasma-coated charcoal. Nonspecific interference with the assay system was excluded by extraction of plasm samples with ethanol. The reliability of the assay was investigated by recovery experiments, by serial dilution of plasma samples with high concentration of endogenous VIP, and by immunosorption. The within-and between assay reproducibility at a concentration of 18.3 pmol x L/sup -1/ was 1.6 and 2.3 pmol x L/sup -1/ (1 S.D.), respectively. Median fasting concentration of VIP in plasma from 74 normal subjects was 7.3 pmol x L/sup -1/ (range: 0 to 20.0 pmol x L/sup -1/).

  13. Comparative assessment of in vitro release kinetics of calcitonin polypeptide from biodegradable microspheres.

    Science.gov (United States)

    Prabhu, Sunil; Sullivan, Jennifer L; Betageri, Guru V

    2002-01-01

    The objective of our study was to compare the in vitro release kinetics of a sustained-release injectable microsphere formulation of the polypeptide drug, calcitonin (CT), to optimize the characteristics of drug release from poly-(lactide-co-glycolide) (PLGA) copolymer biodegradable microspheres. A modified solvent evaporation and double emulsion technique was used to prepare the microspheres. Release kinetic studies were carried out in silanized tubes and dialysis bags, whereby microspheres were suspended and incubated in phosphate buffered saline, sampled at fixed intervals, and analyzed for drug content using a modified Lowry protein assay procedure. An initial burst was observed whereby about 50% of the total dose of the drug was released from the microspheres within 24 hr and 75% within 3 days. This was followed by a period of slow release over a period of 3 weeks in which another 10-15% of drug was released. Drug release from the dialysis bags was more gradual, and 50% CT was released only after 4 days and 75% after 12 days of release. Scanning electron micrographs revealed spherical particles with channel-like structures and a porous surface after being suspended in an aqueous solution for 5 days. Differential scanning calorimetric studies revealed that CT was present as a mix of amorphous and crystalline forms within the microspheres. Overall, these studies demonstrated that sustained release of CT from PLGA microspheres over a 3-week period is feasible and that release of drug from dialysis bags was more predictable than from tubes.

  14. Maternally Sequestered Therapeutic Polypeptides – A New Approach for the Management of Preeclampsia

    Directory of Open Access Journals (Sweden)

    Eric eGeorge

    2014-09-01

    Full Text Available The last several decades have seen intensive research into the molecular mechanisms underlying the symptoms of preeclampsia. While the underlying cause of preeclampsia is believed to be defective placental development and resulting placental ischemia, it is only recently that the links between the ischemic placenta and maternal symptomatic manifestation have been elucidated. Several different pathways have been implicated in the development of the disorder; most notably production of the anti-angiogenic protein sFlt-1, induction of auto-immunity and inflammation, and production of reactive oxygen species. While the molecular mechanisms are becoming clearer, translating that knowledge into effective therapeutics has proven elusive. Here we describe a number of peptide based therapies we have developed to target theses pathways, and which are currently being tested in preclinical models. These therapeutics are based on a synthetic polymeric carrier elastin-like polypeptide (ELP, which can be synthesized in various sequences and sizes to stabilize the therapeutic peptide and avoid crossing the placental interface. This prevents fetal exposure and potential developmental effects. The therapeutics designed will target known pathogenic pathways, and the ELP carrier could prove to be a versatile delivery system for administration of a variety of therapeutics during pregnancy.

  15. Glucose-Dependent Insulinotropic Polypeptide Mitigates 6-OHDA-Induced Behavioral Impairments in Parkinsonian Rats

    Science.gov (United States)

    Yu, Yu-Wen; Hsueh, Shih-Chang; Lai, Jing-Huei; Chen, Yen-Hua; Kang, Shuo-Jhen; Hsieh, Tsung-Hsun; Hoffer, Barry J.; Li, Yazhou; Greig, Nigel H.; Chiang, Yung-Hsiao

    2018-01-01

    In the present study, the effectiveness of glucose-dependent insulinotropic polypeptide (GIP) was evaluated by behavioral tests in 6-hydroxydopamine (6-OHDA) hemi-parkinsonian (PD) rats. Pharmacokinetic measurements of GIP were carried out at the same dose studied behaviorally, as well as at a lower dose used previously. GIP was delivered by subcutaneous administration (s.c.) using implanted ALZET micro-osmotic pumps. After two days of pre-treatment, male Sprague Dawley rats received a single unilateral injection of 6-OHDA into the medial forebrain bundle (MFB). The neuroprotective effects of GIP were evaluated by apomorphine-induced contralateral rotations, as well as by locomotor and anxiety-like behaviors in open-field tests. Concentrations of human active and total GIP were measured in plasma during a five-day treatment period by ELISA and were found to be within a clinically translatable range. GIP pretreatment reduced behavioral abnormalities induced by the unilateral nigrostriatal dopamine (DA) lesion produced by 6-OHDA, and thus may be a novel target for PD therapeutic development. PMID:29641447

  16. Pituitary Adenylate Cyclase-Activating Polypeptide Reverses Ammonium Metavanadate-Induced Airway Hyperresponsiveness in Rats

    Directory of Open Access Journals (Sweden)

    Mounira Tlili

    2015-01-01

    Full Text Available The rate of atmospheric vanadium is constantly increasing due to fossil fuel combustion. This environmental pollution favours vanadium exposure in particular to its vanadate form, causing occupational bronchial asthma and bronchitis. Based on the well admitted bronchodilator properties of the pituitary adenylate cyclase-activating polypeptide (PACAP, we investigated the ability of this neuropeptide to reverse the vanadate-induced airway hyperresponsiveness in rats. Exposure to ammonium metavanadate aerosols (5 mg/m3/h for 15 minutes induced 4 hours later an array of pathophysiological events, including increase of bronchial resistance and histological alterations, activation of proinflammatory alveolar macrophages, and increased oxidative stress status. Powerfully, PACAP inhalation (0.1 mM for 10 minutes alleviated many of these deleterious effects as demonstrated by a decrease of bronchial resistance and histological restoration. PACAP reduced the level of expression of mRNA encoding inflammatory chemokines (MIP-1α, MIP-2, and KC and cytokines (IL-1α and TNF-α in alveolar macrophages and improved the antioxidant status. PACAP reverses the vanadate-induced airway hyperresponsiveness not only through its bronchodilator activity but also by counteracting the proinflammatory and prooxidative effects of the metal. Then, the development of stable analogs of PACAP could represent a promising therapeutic alternative for the treatment of inflammatory respiratory disorders.

  17. Sustained release of antibiotics from injectable and thermally responsive polypeptide depots.

    Science.gov (United States)

    Adams, Samuel B; Shamji, Mohammed F; Nettles, Dana L; Hwang, Priscilla; Setton, Lori A

    2009-07-01

    Biodegradable polymeric scaffolds are of interest for delivering antibiotics to local sites of infection in orthopaedic applications, such as bone and diarthrodial joints. The objective of this study was to develop a biodegradable scaffold with ease of drug loading in aqueous solution, while providing for drug depot delivery via syringe injection. Elastin-like polypeptides (ELPs) were used for this application, biopolymers of repeating pentapeptide sequences that were thermally triggered to undergo in situ depot formation at body temperature. ELPs were modified to enable loading with the antibiotics, cefazolin, and vancomycin, followed by induction of the phase transition in vitro. Cefazolin and vancomycin concentrations were monitored, as well as bioactivity of the released antibiotics, to test an ability of the ELP depot to provide for prolonged release of bioactive drugs. Further tests of formulation viscosity were conducted to test suitability as an injectable drug carrier. Results demonstrate sustained release of therapeutic concentrations of bioactive antibiotics by the ELP, with first-order time constants for drug release of approximately 25 h for cefazolin and approximately 500 h for vancomycin. These findings illustrate that an injectable, in situ forming ELP depot can provide for sustained release of antibiotics with an effect that varies across antibiotic formulation. ELPs have important advantages for drug delivery, as they are known to be biocompatible, biodegradable, and elicit no known immune response. These benefits suggest distinct advantages over currently used carriers for antibiotic drug delivery in orthopedic applications. (c) 2008 Wiley Periodicals, Inc.

  18. Degradation of surface-labeled hepatoma membrane polypeptides: effect of inhibitors

    International Nuclear Information System (INIS)

    Hare, J.F.; Huston, M.

    1984-01-01

    When their membrane proteins were labeled with 125I by lactoperoxidase, dividing hepatoma cells lost radioactivity to the medium in a biphasic manner (T1/2 . 16-26 h, greater than 40 h). Lysosomotropic weak bases, chloroquine, and NH4Cl inhibited the rapid phase by 59%. More than 50% of the radioactivity which accumulates in the media from dividing cells during the first 4 h after labeling was trichloroacetic acid-soluble, and was identified as iodotyrosine. Iodotyrosine release from labeled membrane proteins was 60-71% inhibited by lysosomotropic agents chloroquine and NH4Cl as well as the sodium-proton ionophore, monensin. The inhibitory effect of NH4Cl and monensin was reversible. Inhibitors of microtubule and microfilament function and transglutamination had no effect on release of iodotyrosine to the medium, but trypsin-like protease inhibitors, p-aminobenzamidine, tosyl-L-lysine/chloromethylketone, and phenylmethylsulfonyl fluoride, as well as the cathepsin B inhibitor, leupeptin, inhibited by 21-24%. Iodotyrosine release showed a biphasic Arrhenius plot with an activation energy of 17 kcal/mol above but 27 kcal/mol below 20 degrees C. These results indicate that cell membrane polypeptides require a temperature-limiting event as well as passage through an ion-sensitive compartment prior to their complete degradation to constituent amino acids. In contrast to other lysosomal-mediated events, however, iodinated membrane proteins of dividing cells are degraded in a manner insensitive to agents which disrupt the cytoskeleton

  19. A paclitaxel-loaded recombinant polypeptide nanoparticle outperforms Abraxane in multiple murine cancer models

    Science.gov (United States)

    Bhattacharyya, Jayanta; Bellucci, Joseph J.; Weitzhandler, Isaac; McDaniel, Jonathan R.; Spasojevic, Ivan; Li, Xinghai; Lin, Chao-Chieh; Chi, Jen-Tsan Ashley; Chilkoti, Ashutosh

    2015-08-01

    Packaging clinically relevant hydrophobic drugs into a self-assembled nanoparticle can improve their aqueous solubility, plasma half-life, tumour-specific uptake and therapeutic potential. To this end, here we conjugated paclitaxel (PTX) to recombinant chimeric polypeptides (CPs) that spontaneously self-assemble into ~60 nm near-monodisperse nanoparticles that increased the systemic exposure of PTX by sevenfold compared with free drug and twofold compared with the Food and Drug Administration-approved taxane nanoformulation (Abraxane). The tumour uptake of the CP-PTX nanoparticle was fivefold greater than free drug and twofold greater than Abraxane. In a murine cancer model of human triple-negative breast cancer and prostate cancer, CP-PTX induced near-complete tumour regression after a single dose in both tumour models, whereas at the same dose, no mice treated with Abraxane survived for >80 days (breast) and 60 days (prostate), respectively. These results show that a molecularly engineered nanoparticle with precisely engineered design features outperforms Abraxane, the current gold standard for PTX delivery.

  20. Genetically encoded lipid-polypeptide hybrid biomaterials that exhibit temperature-triggered hierarchical self-assembly

    Science.gov (United States)

    Mozhdehi, Davoud; Luginbuhl, Kelli M.; Simon, Joseph R.; Dzuricky, Michael; Berger, Rüdiger; Varol, H. Samet; Huang, Fred C.; Buehne, Kristen L.; Mayne, Nicholas R.; Weitzhandler, Isaac; Bonn, Mischa; Parekh, Sapun H.; Chilkoti, Ashutosh

    2018-05-01

    Post-translational modification of proteins is a strategy widely used in biological systems. It expands the diversity of the proteome and allows for tailoring of both the function and localization of proteins within cells as well as the material properties of structural proteins and matrices. Despite their ubiquity in biology, with a few exceptions, the potential of post-translational modifications in biomaterials synthesis has remained largely untapped. As a proof of concept to demonstrate the feasibility of creating a genetically encoded biohybrid material through post-translational modification, we report here the generation of a family of three stimulus-responsive hybrid materials—fatty-acid-modified elastin-like polypeptides—using a one-pot recombinant expression and post-translational lipidation methodology. These hybrid biomaterials contain an amphiphilic domain, composed of a β-sheet-forming peptide that is post-translationally functionalized with a C14 alkyl chain, fused to a thermally responsive elastin-like polypeptide. They exhibit temperature-triggered hierarchical self-assembly across multiple length scales with varied structure and material properties that can be controlled at the sequence level.

  1. The polypeptide in Chlamys farreri can protect human dermal fibroblasts from ultraviolet B damage

    Science.gov (United States)

    Zhang, Yujiang; Zhan, Songmei; Cao, Pengli; Liu, Ning; Chen, Xuehong; Wang, Yuejun; Wang, Chunbo

    2005-09-01

    To investigate the effect of polypeptide from Chlamys farreri (PCF) on NHDF in vitro, we modeled oxidative damage on normal human dermal fibroblasts (NHDF) exposed to ultraviolet B (UVB). In this study, 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) were tested to measure cell viability. Enzymes including superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), catalase (CAT) and xanthine oxidase (XOD) were determined biochemically. Total antioxidative capacity (T-AOC) and anti-superoxide anion capacity (A-SAC) were also determined. Ultrastructure of fibroblasts was observed under transmission electron microscope. The results showed that: UVB (1.176×10-4 J/cm2) suppressed the growth of fibroblasts and the introduction of PCF (0.25% 1%) before UVB reduced the suppression in a concentration-dependent manner. PCF could enhance the activities of SOD, GSH-PX and T-AOC as well as A-SAC. Also PCF could inhibit XOD activity, while it did not affect CAT activity. Ultrastructure of fibroblasts were damaged after UVB irradiation, concentration-dependent PCF reduced the destructive effect of UVB on cells. These results indicated that PCF can protect human dermal fibroblasts from being harmed by UVB irradiation via its antioxidant proerty.

  2. Role of pancreatic polypeptide in the regulation of pancreatic exocrine secretion in dogs

    International Nuclear Information System (INIS)

    Shiratori, Keiko; Lee, K.Y.; Chang, Tamin; Jo, Y.H.; Coy, D.H.; Chey, W.Y.

    1988-01-01

    The effect of intravenous infusion of synthetic human pancreatic polypeptide (HPP) or a rabbit anti-PP serum on pancreatic exocrine secretion was studied in 10 dogs with gastric and Thomas duodenal cannulas. The infusion of HPP, achieved a plasma PP concentration that mimicked the peak plasma concentration of PP in both interdigestive and postprandial states. This dose of HPP significantly inhibited pancreatic secretion in the interdigestive state. By contrast, immunoneutralization of circulating PP by a rabbit anti-PP serum resulted in significant increases in both interdigestive and postprandial pancreatic secretion, including water, bicarbonate, and protein. The increase in the pancreatic secretion paralleled a decrease in circulating PP level, which lasted for as long as 5 days. Furthermore, the anti-PP serum blocked the inhibitory action of exogenous HPP on pancreatic exocrine secretion. The present study indicates that endogenous PP plays a significant role in the regulation of the pancreatic exocrine secretion in both interdigestive and digestive states. Thus the authors conclude that PP is another hormone regulating pancreatic exocrine secretion in dogs

  3. Production and characterization of monoclonal antibodies that discriminate among individual S100 polypeptides

    International Nuclear Information System (INIS)

    Van Eldik, L.J.

    1984-01-01

    The term S100 refers to a heterogeneous fraction of low molecular weight, acidic, calcium binding proteins. The S100 fraction is a mixture of polypeptides, only some of which have been isolated and characterized. The amino acid sequences of two S100 proteins from bovine brain, S100α and S100β, have been determined. The physiological functions of the S100 proteins are not known. Although assay of immunoreactive S100 has been used clinically to screen tumors of neural origin, as an index of cell injury in various disorders, and as an index of malignancy, most of the antisera used in previous studies react with more than one protein in the S100 fraction. Even the currently available monoclonal antibodies against S100 (2-4) do not appear to measure the individual S100α and S100β components. In order to unequivocally interpret studies on the localization of S100 and its potential alterations in various disease states, and on the validity of S100 immunoreactivity as a diagnostic tool for tumor diagnosis, it would be useful to have antibodies that discriminate among the individual S100 components. The authors report here the production of monoclonal antibodies that appear to be specific for S100β

  4. Angioplastic necrolytic migratory erythema. Unique association of necrolytic migratory erythema, extensive angioplasia, and high molecular weight glucagon-like polypeptide

    International Nuclear Information System (INIS)

    Franchimont, C.; Pierard, G.E.; Luyckx, A.S.; Gerard, J.; Lapiere, C.M.

    1982-01-01

    A diabetic patient developed necrolytic migratory erythema with extensive angioplasia and high molecular weight glucagon-like polypeptide. There was no associated neoplasm such as glucagonoma. Lesions in the skin were studied by standard optical microscopy and by radioautography after incorporation of tritiated thymidine. Alterations in the skin begin as focal necrosis in the epidermis and in epithelial structures of adnexa, followed by marked angioplasia and a superficial and deep perivascular dermatitis

  5. Induction of a M/sub r/ 21,000 polypeptide in an Arthrobacter Sp. by dye-sensitized photooxidation

    International Nuclear Information System (INIS)

    Franzi, J.J.

    1985-01-01

    Irradiation of aerobic cultures of an Arthrobacter species with near-UV light and oxygen induced synthesis of a cell surface protein, M/sub r/ 21,000 polypeptide. Visible light, oxygen and a sensitizing dye were also effective in induction. Far-UV light, bleomycin and nalidixic acid, all inducers of the recA protein in Escherichia coli, were ineffective inducers of this protein. Furthermore, X-irradiation and radical-generating oxidants failed to induce synthesis of the M/sub r/ 21,000 polypeptide. DNA binding dyes proved to be capable of inducing synthesis of this protein or inhibiting dye-mediated stimulation of synthesis of this protein. For example, dGdC-specific dyes (e.g. methylene blue, neutral red, acridine orange or ethidium bromide) were efficient inducers of the M/sub r/ 21,000 polypeptide. Also methylene blue and neutral red were more efficient inducers than were acridine orange or ethidium bromide, which could be explained by the greater dGdC specificity and, possibly by the greater photoreactivity of methylene blue and neutral red. dAdT-specific dyes such as methyl green or daunomycin effectively inhibited dye-mediated induction. Rose bengal is an anionic dye which does not bind to DNA but does mediate the photooxidation of deoxyguanosine residues in DNA. It is an efficient inducer of the M/sub r/ 21,000 polypeptide. Induction with this dye is nearly eliminated when novobiocin, an inhibitor of DNA gyrase (topoisomerase II) which mediates relaxation, is added in conjunction with rose bengal

  6. Induction of a M/sub r/ 21,000 polypeptide in an Arthrobacter Sp. by dye-sensitized photooxidation

    Energy Technology Data Exchange (ETDEWEB)

    Franzi, J.J.

    1985-01-01

    Irradiation of aerobic cultures of an Arthrobacter species with near-UV light and oxygen induced synthesis of a cell surface protein, M/sub r/ 21,000 polypeptide. Visible light, oxygen and a sensitizing dye were also effective in induction. Far-UV light, bleomycin and nalidixic acid, all inducers of the recA protein in Escherichia coli, were ineffective inducers of this protein. Furthermore, X-irradiation and radical-generating oxidants failed to induce synthesis of the M/sub r/ 21,000 polypeptide. DNA binding dyes proved to be capable of inducing synthesis of this protein or inhibiting dye-mediated stimulation of synthesis of this protein. For example, dGdC-specific dyes (e.g. methylene blue, neutral red, acridine orange or ethidium bromide) were efficient inducers of the M/sub r/ 21,000 polypeptide. Also methylene blue and neutral red were more efficient inducers than were acridine orange or ethidium bromide, which could be explained by the greater dGdC specificity and, possibly by the greater photoreactivity of methylene blue and neutral red. dAdT-specific dyes such as methyl green or daunomycin effectively inhibited dye-mediated induction. Rose bengal is an anionic dye which does not bind to DNA but does mediate the photooxidation of deoxyguanosine residues in DNA. It is an efficient inducer of the M/sub r/ 21,000 polypeptide. Induction with this dye is nearly eliminated when novobiocin, an inhibitor of DNA gyrase (topoisomerase II) which mediates relaxation, is added in conjunction with rose bengal.

  7. Short term aerobic exercise training increases postprandial pancreatic polypeptide but not peptide YY concentrations in obese individuals

    OpenAIRE

    Kanaley, Jill A.; Heden, Timothy D.; Liu, Ying; Whaley-Connell, Adam T.; Chockalingam, Anand; Dellsperger, Kevin C.; Fairchild, Timothy J.

    2013-01-01

    Objective Short-term exercise training improves glycemic control, but the effect of short-term training on postprandial satiety peptide responses or perceived satiety remains unknown. We tested the hypothesis that short-term aerobic exercise training (15 days) would alter postprandial pancreatic and gut peptide [pancreatic polypeptide (PP) and peptide YY (PYY)] responses and perceived appetite and satiety in obese individuals. Subjects Thirteen healthy obese men and women (age: 42±2 y; BMI: 3...

  8. Is pancreatic polypeptide response to food ingestion a reliable index of vagal function in type 1 diabetes?

    DEFF Research Database (Denmark)

    Damholt, M B; Arlien-Soeborg, P; Hilsted, L

    2006-01-01

    The diagnosis of autonomic neuropathy in diabetic patients is based on cardiovascular reflex tests. Since cardiac function may be affected by arteriosclerosis and cardiomyopathy in type 1 diabetes mellitus, alternative tests reflecting vagal nerve function, in other organ systems, are needed....... In this study the pancreatic polypeptide (PP) response to a mixed meal was evaluated in healthy subjects and in recently diagnosed type 1 diabetic patients....

  9. Beta-glucosidase variants and polynucleotides encoding same

    Science.gov (United States)

    Wogulis, Mark; Harris, Paul; Osborn, David

    2017-06-27

    The present invention relates to beta-glucosidase variants, e.g. beta-glucosidase variants of a parent Family GH3A beta-glucosidase from Aspergillus fumigatus. The present invention also relates to polynucleotides encoding the beta-glucosidase variants; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the beta-glucosidase variants.

  10. Identification of UDPG-binding polypeptides and purified (1,3)-β-glucan synthase by photoaffinity labelling with 5-azido-UDPG

    International Nuclear Information System (INIS)

    Frost, D.J.; Wu, A.; Read, S.M.; Wasserman, B.P.; Drake, R.R.; Haley, B.E.

    1989-01-01

    The photoaffinity probe 5-azido-uridine 5'-β-[ 32 P]-diphosphate glucose was used to identify the major UDPG-binding polypeptide of red beet (1,3)-β-glucan synthase. Glucan synthase was purified from plasma membranes by sequential solubilization with CHAPS followed by product entrapment. Two major polypeptides at 72 and 54 kD were labelled by probe. Labelling of both was abolished with increasing levels of cold UDPG. However, labelling of the 54 kD polypeptide was dependent upon the presence of divalent cations. These data suggest that the 54 kD polypeptide is a substrate-binding and cation-regulated component of the glucan synthase complex

  11. Recombinant DNA specifying the human amyloid. beta. precursor protein (ABPP) encodes a 95-kDa polypeptide

    Energy Technology Data Exchange (ETDEWEB)

    Mita, S; Sadlock, J; Herbert, J; Schon, E A

    1988-10-11

    Although the ABPP gene give rise to multiple mRNAs, the primary translation product of this gene is unknown. The longest published cDNA sequences predict a 770-aa polypeptide of 87 kDa. However, in immunoblots, ABPP migrated as a single species of >92 kDa in rat brain, and in human, as a species of 95-100 kDa in non-membrane bound form, as multiple species of 110-135 kDa in membrane-associated form and as a 130-kDa species in fibroblasts. The sizes of these larger species relative to the MW of ABPP predicted from the cDNA sequences have been attributed to postranslational modification. However, the authors have isolated a cDNA (lambdaHAP2) from a human fetal muscle lambdagt11 cDNA library encoding an 843-aa polypeptide with a deduced MW of 94,642. This cDNA contains both exons encoding an 843-aa polypeptide with a deduced MW of 94.642. This cDNA contains both exons encoding the protease inhibitor domains. Primer extension analysis indicates that the 5' terminus of this cDNA is 14 nt from a transcriptional start site. This cDNA, encoding the longest ABPP described to date, may explain some of the observations on the sizes of tissue-derived ABPP.

  12. Characterization of cell surface polypeptides of unfertilized, fertilized, and protease-treated zona-free mouse eggs

    International Nuclear Information System (INIS)

    Boldt, J.; Gunter, L.E.; Howe, A.M.

    1989-01-01

    The polypeptide composition of unfertilized, fertilized, and protease-treated zona-free mouse eggs was evaluated in this study. Zona-free eggs were radioiodinated by an Iodogen-catalyzed reaction. Light microscopic autoradiography of egg sections revealed that labeling was restricted to the cell surface. Labeled eggs were solubilized, and cell surface polypeptides were identified by one-dimensional SDS polyacrylamide gel electrophoresis and autoradiography. The unfertilized egg demonstrated 8-10 peptides that incorporated 125 I, with major bands observed at approximately 145-150, 94, and 23 kilodaltons (kD). Zona-free eggs fertilized in vitro and then radiolabeled demonstrated several new bands in comparison to unfertilized eggs, with a major band appearing at approximately 36 kD. Treatment of radiolabeled unfertilized eggs with either trypsin or chymotrypsin (1 mg/ml for 5-20 min) caused enzyme-specific modifications in labeled polypeptides. Trypsin (T) treatment resulted in time-dependant modification of the three major peptides at 145-150, 94, and 23 kD. Chymotrypsin (CT) treatment, in contrast, was associated with loss or modification of the 94 kD band, with no apparent effect on either the 145-150 or 23 kD band. Taken together with previous data indicating that T or CT egg treatment interferes with sperm-egg attachment and fusion, these results suggest a possible role for the 94 kD protein in sperm-egg interaction

  13. Preparation of Photocrosslinked Fish Elastin Polypeptide/Microfibrillated Cellulose Composite Gels with Elastic Properties for Biomaterial Applications

    Directory of Open Access Journals (Sweden)

    Shinya Yano

    2015-01-01

    Full Text Available Photocrosslinked hydrogels reinforced by microfibrillated cellulose (MFC were prepared from a methacrylate-functionalized fish elastin polypeptide and MFC dispersed in dimethylsulfoxide (DMSO. First, a water-soluble elastin peptide with a molecular weight of ca. 500 g/mol from the fish bulbus arteriosus was polymerized by N,N′-dicyclohexylcarbodiimide (DCC, a condensation reagent, and then modified with 2-isocyanatoethyl methacrylate (MOI to yield a photocrosslinkable fish elastin polypeptide. The product was dissolved in DMSO and irradiated with UV light in the presence of a radical photoinitiator. We obtained hydrogels successfully by substitution of DMSO with water. The composite gel with MFC was prepared by UV irradiation of the photocrosslinkable elastin polypeptide mixed with dispersed MFC in DMSO, followed by substitution of DMSO with water. The tensile test of the composite gels revealed that the addition of MFC improved the tensile properties, and the shape of the stress–strain curve of the composite gel became more similar to the typical shape of an elastic material with an increase of MFC content. The rheology measurement showed that the elastic modulus of the composite gel increased with an increase of MFC content. The cell proliferation test on the composite gel showed no toxicity.

  14. Chronic changes in pituitary adenylate cyclase-activating polypeptide and related receptors in response to repeated chemical dural stimulation in rats.

    Science.gov (United States)

    Han, Xun; Ran, Ye; Su, Min; Liu, Yinglu; Tang, Wenjing; Dong, Zhao; Yu, Shengyuan

    2017-01-01

    Background Preclinical experimental studies revealed an acute alteration of pituitary adenylate cyclase-activating polypeptide in response to a single activation of the trigeminovascular system, which suggests a potential role of pituitary adenylate cyclase-activating polypeptide in the pathogenesis of migraine. However, changes in pituitary adenylate cyclase-activating polypeptide after repeated migraine-like attacks in chronic migraine are not clear. Therefore, the present study investigated chronic changes in pituitary adenylate cyclase-activating polypeptide and related receptors in response to repeated chemical dural stimulations in the rat. Methods A rat model of chronic migraine was established by repeated chemical dural stimulations using an inflammatory soup for a different numbers of days. The pituitary adenylate cyclase-activating polypeptide levels were quantified in plasma, the trigeminal ganglia, and the trigeminal nucleus caudalis using radioimmunoassay and Western blotting in trigeminal ganglia and trigeminal nucleus caudalis tissues. Western blot analysis and real-time polymerase chain reaction were used to measure the protein and mRNA expression of pituitary adenylate cyclase-activating polypeptide-related receptors (PAC1, VPAC1, and VPAC2) in the trigeminal ganglia and trigeminal nucleus caudalis to identify changes associated with repetitive applications of chemical dural stimulations. Results All rats exhibited significantly decreased periorbital nociceptive thresholds to repeated inflammatory soup stimulations. Radioimmunoassay and Western blot analysis demonstrated significantly decreased pituitary adenylate cyclase-activating polypeptide levels in plasma and trigeminal ganglia after repetitive chronic inflammatory soup stimulation. Protein and mRNA analyses of pituitary adenylate cyclase-activating polypeptide-related receptors demonstrated significantly increased PAC1 receptor protein and mRNA expression in the trigeminal ganglia, but not

  15. Word Variant Identification in Old French

    Directory of Open Access Journals (Sweden)

    Peter Willett

    1997-01-01

    Full Text Available Increasing numbers of historical texts are available in machine-readable form, which retain the original spelling, which can be very different from the modern-day equivalents due to the natural evolution of a language, and because the concept of standardisation in spelling is comparatively modern. Among medieval vernacular writers, the same word could be spelled in different ways and the same author (or scribe might even use several alternative spellings in the same passage. Thus, we do not know,a priori, how many variant forms of a particular word there are in such texts, let alone what these variants might be. Searching on the modern equivalent, or even the commonest historical variant, of a particular word may thus fail to retrieve an appreciable number of occurrences unless the searcher already has an extensive knowledge of the language of the documents. Moreover, even specialist scholars may be unaware of some idiosyncratic variants. Here, we consider the use of computer methods to retrieve variant historical spellings.

  16. Splicing analysis of 14 BRCA1 missense variants classifies nine variants as pathogenic

    DEFF Research Database (Denmark)

    Ahlborn, Lise B; Dandanell, Mette; Steffensen, Ane Y

    2015-01-01

    by functional analysis at the protein level. Results from a validated mini-gene splicing assay indicated that nine BRCA1 variants resulted in splicing aberrations leading to truncated transcripts and thus can be considered pathogenic (c.4987A>T/p.Met1663Leu, c.4988T>A/p.Met1663Lys, c.5072C>T/p.Thr1691Ile, c......Pathogenic germline mutations in the BRCA1 gene predispose carriers to early onset breast and ovarian cancer. Clinical genetic screening of BRCA1 often reveals variants with uncertain clinical significance, complicating patient and family management. Therefore, functional examinations are urgently...... needed to classify whether these uncertain variants are pathogenic or benign. In this study, we investigated 14 BRCA1 variants by in silico splicing analysis and mini-gene splicing assay. All 14 alterations were missense variants located within the BRCT domain of BRCA1 and had previously been examined...

  17. Molecular cloning and characterization of Antheraea mylitta cytoplasmic polyhedrosis virus polyhedrin gene and its variant forms

    International Nuclear Information System (INIS)

    Sinha-Datta, Uma; Chavali, Venkata Ramana Murthy; Ghosh, Ananta K.

    2005-01-01

    The segments 10 (S10) of the 11 double stranded RNA genomes from Antheraea mylitta cytoplasmic polyhedrosis virus (AmCPV) encoding a novel polyhedrin polypeptide was converted to cDNA, cloned, and sequenced. Three cDNA clones consisting of 1502 (AmCPV10-1), 1120 (AmCPV10-2), and 1415 (AmCPV10-3) nucleotides encoding polyhedrin of 254, 339, and 319 amino acids with molecular masses of 29, 39, and 37 kDa, respectively, were obtained, and verified by Northern analysis. These clones showed 70-94% sequence identity among them but none with any sequences in databases. The expression of AmCPV10-1 cDNA encoded polyhedrin in Sf-9 cells was detected by immunoblot analysis and formation of polyhedra by electron microscopy, as observed in AmCPV-infected gut cells, but no expression of AmCPV10-2 or AmCPV10-3 cDNA was detected, indicating that during AmCPV replication, along with functional S10 RNA, some defective variant forms of S10 RNAs are packaged in virion particles

  18. Genetics in psychiatry: common variant association studies

    Directory of Open Access Journals (Sweden)

    Buxbaum Joseph D

    2010-03-01

    Full Text Available Abstract Many psychiatric conditions and traits are associated with significant heritability. Genetic risk for psychiatric conditions encompass rare variants, identified due to major effect, as well as common variants, the latter analyzed by association analyses. We review guidelines for common variant association analyses, undertaking after assessing evidence of heritability. We highlight the importance of: suitably large sample sizes; an experimental design that controls for ancestry; careful data cleaning; correction for multiple testing; small P values for positive findings; assessment of effect size for positive findings; and, inclusion of an independent replication sample. We also note the importance of a critical discussion of any prior findings, biological follow-up where possible, and a means of accessing the raw data.

  19. Hemoglobin Variants: Biochemical Properties and Clinical Correlates

    Science.gov (United States)

    Thom, Christopher S.; Dickson, Claire F.; Gell, David A.; Weiss, Mitchell J.

    2013-01-01

    Diseases affecting hemoglobin synthesis and function are extremely common worldwide. More than 1000 naturally occurring human hemoglobin variants with single amino acid substitutions throughout the molecule have been discovered, mainly through their clinical and/or laboratory manifestations. These variants alter hemoglobin structure and biochemical properties with physiological effects ranging from insignificant to severe. Studies of these mutations in patients and in the laboratory have produced a wealth of information on hemoglobin biochemistry and biology with significant implications for hematology practice. More generally, landmark studies of hemoglobin performed over the past 60 years have established important paradigms for the disciplines of structural biology, genetics, biochemistry, and medicine. Here we review the major classes of hemoglobin variants, emphasizing general concepts and illustrative examples. PMID:23388674

  20. The multi-epitope polypeptide approach in HIV-1 vaccine development.

    Science.gov (United States)

    Cano, C A

    1999-11-01

    The application of a preventive HIV vaccine is the only hope for most developing countries to halt the AIDS pandemic. A project aimed to develop a preventive AIDS vaccine is being carried out since 1992 by three Cuban research institutions: Centro de Ingeniería Genética y Biotecnologia de La Habana, Instituto de Medicina Tropical 'Pedro Kouri' and Laboratorio de Investigaciones de SIDA de La Habana. The project includes two main strategies: (a) generation of recombinant multi-epitope polypeptides (MEPs) bearing several copies of the V3 loop from different HIV-1 isolates; and (b) development of immunogens capable of inducing a cytotoxic T cell response (CTL) specific for human immunodeficiency virus type 1 (HIV-1) antigens. This article summarizes the work in the first of these strategies. Based on the sequence of the V3 loop of HIV-1 we constructed a series of MEPs and evaluated their immunogenicity in mice, rabbits and macaques. The MEP TAB9, containing six V3 epitopes from isolates LR10, JY1, RF, MN, BRVA and IIIB, was selected together with the oil adjuvant Montanide ISA720 (SEPPIC, France) to perform a Phase I clinical trial in HIV seronegative Cuban volunteers. The trial was double blinded, randomized, and fulfilled all ethical and regulatory requirements. All TAB9 vaccinated volunteers developed a strong immune response and neutralizing antibodies were observed in the 50% of the subjects. However the second and third inoculations of the vaccine were not well tolerated because transient severe local reactions appeared in some individuals. A new formulation of TAB9 is currently in pre-clinical studies and is expected to enter clinical trials in 1999.

  1. Pituitary adenylate cyclase activating polypeptide modulates catecholamine storage and exocytosis in PC12 cells.

    Directory of Open Access Journals (Sweden)

    Yan Dong

    Full Text Available A number of efforts have been made to understand how pituitary adenylate cyclase activating polypeptide (PACAP functions as a neurotrophic and neuroprotective factor in Parkinson's disease (PD. Recently its effects on neurotransmission and underlying mechanisms have generated interest. In the present study, we investigate the effects of PACAP on catecholamine storage and secretion in PC12 cells with amperometry and transmission electron microscopy (TEM. PACAP increases quantal release induced by high K+ without significantly regulating the frequency of vesicle fusion events. TEM data indicate that the increased volume of the vesicle is mainly the result of enlargement of the fluidic space around the dense core. Moreover, the number of docked vesicles isn't modulated by PACAP. When cells are acutely treated with L-DOPA, the vesicular volume and quantal release both increase dramatically. It is likely that the characteristics of amperometric spikes from L-DOPA treated cells are associated with increased volume of individual vesicles rather than a direct effect on the mechanics of exocytosis. Treatment with PACAP versus L-DOPA results in different profiles of the dynamics of exocytosis. Release via the fusion pore prior to full exocytosis was observed with the same frequency following treatment with PACAP and L-DOPA. However, release events have a shorter duration and higher average current after PACAP treatment compared to L-DOPA. Furthermore, PACAP reduced the proportion of spikes having rapid decay time and shortened the decay time of both fast and slow spikes. In contrast, the distributions of the amperometric spike decay for both fast and slow spikes were shifted to longer time following L-DOPA treatment. Compared to L-DOPA, PACAP may produce multiple favorable effects on dopaminergic neurons, including protecting dopaminergic neurons against neurodegeneration and potentially regulating dopamine storage and release, making it a promising

  2. Effects of velvet antler polypeptide on sexual behavior and testosterone synthesis in aging male mice.

    Science.gov (United States)

    Zang, Zhi-Jun; Tang, Hong-Feng; Tuo, Ying; Xing, Wei-Jie; Ji, Su-Yun; Gao, Yong; Deng, Chun-Hua

    2016-01-01

    Twenty-four-month-old male C57BL/6 mice with low serum testosterone levels were used as a late-onset hypogonadism (LOH) animal model for examining the effects of velvet antler polypeptide (VAP) on sexual function and testosterone synthesis. These mice received VAP for 5 consecutive weeks by daily gavage at doses of 100, 200, or 300 mg kg-1 body weight per day (n = 10 mice per dose). Control animals (n = 10) received the same weight-based volume of vehicle. Sexual behavior and testosterone levels in serum and interstitial tissue of testis were measured after the last administration of VAP. Furthermore, to investigate the mechanisms of how VAP affects sexual behavior and testosterone synthesis in vivo, the expression of steroidogenic acute regulatory protein (StAR), cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc), and 3β-hydroxysteroid dehydrogenase (3β-HSD) in Leydig cells was also measured by immunofluorescence staining and quantitative real-time PCR. As a result, VAP produced a significant improvement in the sexual function of these aging male mice. Serum testosterone level and intratesticular testosterone (ITT) concentration also increased in the VAP-treated groups. The expression of StAR, P450scc, and 3β-HSD was also found to be enhanced in the VAP-treated groups compared with the control group. Our results suggested that VAP was effective in improving sexual function in aging male mice. The effect of velvet antler on sexual function was due to the increased expression of several rate-limiting enzymes of testosterone synthesis (StAR, P450scc, and 3β-HSD) and the following promotion of testosterone synthesis in vivo.

  3. Pituitary Adenylate-Cyclase Activating Polypeptide Regulates Hunger- and Palatability-Induced Binge Eating

    Directory of Open Access Journals (Sweden)

    Matthew M. Hurley

    2016-08-01

    Full Text Available While pituitary adenylate cyclase activating polypeptide (PACAP signaling in the hypothalamic ventromedial nuclei (VMN has been shown to regulate feeding, a challenge in unmasking a role for this peptide in obesity is that excess feeding can involve numerous mechanisms including homeostatic (hunger and hedonic-related (palatability drives. In these studies, we first isolated distinct feeding drives by developing a novel model of binge behavior in which homeostatic-driven feeding was temporally separated from feeding driven by food palatability. We found that stimulation of the VMN, achieved by local microinjections of AMPA, decreased standard chow consumption in food-restricted rats (e.g., homeostatic feeding; surprisingly, this manipulation failed to alter palatable food consumption in satiated rats (e.g., hedonic feeding. In contrast, inhibition of the nucleus accumbens (NAc, through local microinjections of GABA receptor agonists baclofen and muscimol, decreased hedonic feeding without altering homeostatic feeding. PACAP microinjections produced the site-specific changes in synaptic transmission needed to decrease feeding via VMN or NAc circuitry. PACAP into the NAc mimicked the actions of GABA agonists by reducing hedonic feeding without altering homeostatic feeding. In contrast, PACAP into the VMN mimicked the actions of AMPA by decreasing homeostatic feeding without affecting hedonic feeding. Slice electrophysiology recordings verified PACAP excitation of VMN neurons and inhibition of NAc neurons. These data suggest that the VMN and NAc regulate distinct circuits giving rise to unique feeding drives, but that both can be regulated by the neuropeptide PACAP to potentially curb excessive eating stemming from either drive.

  4. Chaperones ameliorate beta cell dysfunction associated with human islet amyloid polypeptide overexpression.

    Directory of Open Access Journals (Sweden)

    Lisa Cadavez

    Full Text Available In type 2 diabetes, beta-cell dysfunction is thought to be due to several causes, one being the formation of toxic protein aggregates called islet amyloid, formed by accumulations of misfolded human islet amyloid polypeptide (hIAPP. The process of hIAPP misfolding and aggregation is one of the factors that may activate the unfolded protein response (UPR, perturbing endoplasmic reticulum (ER homeostasis. Molecular chaperones have been described to be important in regulating ER response to ER stress. In the present work, we evaluate the role of chaperones in a stressed cellular model of hIAPP overexpression. A rat pancreatic beta-cell line expressing hIAPP exposed to thapsigargin or treated with high glucose and palmitic acid, both of which are known ER stress inducers, showed an increase in ER stress genes when compared to INS1E cells expressing rat IAPP or INS1E control cells. Treatment with molecular chaperone glucose-regulated protein 78 kDa (GRP78, also known as BiP or protein disulfite isomerase (PDI, and chemical chaperones taurine-conjugated ursodeoxycholic acid (TUDCA or 4-phenylbutyrate (PBA, alleviated ER stress and increased insulin secretion in hIAPP-expressing cells. Our results suggest that the overexpression of hIAPP induces a stronger response of ER stress markers. Moreover, endogenous and chemical chaperones are able to ameliorate induced ER stress and increase insulin secretion, suggesting that improving chaperone capacity can play an important role in improving beta-cell function in type 2 diabetes.

  5. Controlling the Size and Shape of the Elastin-Like Polypeptide based Micelles

    Science.gov (United States)

    Streletzky, Kiril; Shuman, Hannah; Maraschky, Adam; Holland, Nolan

    Elastin-like polypeptide (ELP) trimer constructs make reliable environmentally responsive micellar systems because they exhibit a controllable transition from being water-soluble at low temperatures to aggregating at high temperatures. It has been shown that depending on the specific details of the ELP design (length of the ELP chain, pH and salt concentration) micelles can vary in size and shape between spherical micelles with diameter 30-100 nm to elongated particles with an aspect ratio of about 10. This makes ELP trimers a convenient platform for developing potential drug delivery and bio-sensing applications as well as for understanding micelle formation in ELP systems. Since at a given salt concentration, the headgroup area for each foldon should be constant, the size of the micelles is expected to be proportional to the volume of the linear ELP available per foldon headgroup. Therefore, adding linear ELPs to a system of ELP-foldon should result in changes of the micelle volume allowing to control micelle size and possibly shape. The effects of addition of linear ELPs on size, shape, and molecular weight of micelles at different salt concentrations were studied by a combination of Dynamic Light Scattering and Static Light Scattering. The initial results on 50 µM ELP-foldon samples (at low salt) show that Rh of mixed micelles increases more than 5-fold as the amount of linear ELP raised from 0 to 50 µM. It was also found that a given mixture of linear and trimer constructs has two temperature-based transitions and therefore displays three predominant size regimes.

  6. Light Scattering Study of Mixed Micelles Made from Elastin-Like Polypeptide Linear Chains and Trimers

    Science.gov (United States)

    Terrano, Daniel; Tsuper, Ilona; Maraschky, Adam; Holland, Nolan; Streletzky, Kiril

    Temperature sensitive nanoparticles were generated from a construct (H20F) of three chains of elastin-like polypeptides (ELP) linked to a negatively charged foldon domain. This ELP system was mixed at different ratios with linear chains of ELP (H40L) which lacks the foldon domain. The mixed system is soluble at room temperature and at a transition temperature (Tt) will form swollen micelles with the hydrophobic linear chains hidden inside. This system was studied using depolarized dynamic light scattering (DDLS) and static light scattering (SLS) to determine the size, shape, and internal structure of the mixed micelles. The mixed micelle in equal parts of H20F and H40L show a constant apparent hydrodynamic radius of 40-45 nm at the concentration window from 25:25 to 60:60 uM (1:1 ratio). At a fixed 50 uM concentration of the H20F, varying H40L concentration from 5 to 80 uM resulted in a linear growth in the hydrodynamic radius from about 11 to about 62 nm, along with a 1000-fold increase in VH signal. A possible simple model explaining the growth of the swollen micelles is considered. Lastly, the VH signal can indicate elongation in the geometry of the particle or could possibly be a result from anisotropic properties from the core of the micelle. SLS was used to study the molecular weight, and the radius of gyration of the micelle to help identify the structure and morphology of mixed micelles and the tangible cause of the VH signal.

  7. The effect of gastric inhibitory polypeptide on intestinal glucose absorption and intestinal motility in mice

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Eiichi [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Hosokawa, Masaya [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Faculty of Human Sciences, Tezukayama Gakuin University, Osaka (Japan); Harada, Norio; Yamane, Shunsuke; Hamasaki, Akihiro; Toyoda, Kentaro; Fujimoto, Shimpei; Fujita, Yoshihito; Fukuda, Kazuhito [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Tsukiyama, Katsushi; Yamada, Yuichiro [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Department of Internal Medicine, Division of Endocrinology, Diabetes and Geriatric Medicine, Akita University School of Medicine, Akita (Japan); Seino, Yutaka [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); Kansai Electric Power Hospital, Osaka (Japan); Inagaki, Nobuya, E-mail: inagaki@metab.kuhp.kyoto-u.ac.jp [Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University (Japan); CREST of Japan Science and Technology Cooperation (JST), Kyoto (Japan)

    2011-01-07

    Research highlights: {yields} Exogenous GIP inhibits intestinal motility through a somatostatin-mediated pathway. {yields} Exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility. {yields} The GIP-receptor-mediated action in intestine does not involve in GLP-1-mediated pathway. -- Abstract: Gastric inhibitory polypeptide (GIP) is released from the small intestine upon meal ingestion and increases insulin secretion from pancreatic {beta} cells. Although the GIP receptor is known to be expressed in small intestine, the effects of GIP in small intestine are not fully understood. This study was designed to clarify the effect of GIP on intestinal glucose absorption and intestinal motility. Intestinal glucose absorption in vivo was measured by single-pass perfusion method. Incorporation of [{sup 14}C]-glucose into everted jejunal rings in vitro was used to evaluate the effect of GIP on sodium-glucose co-transporter (SGLT). Motility of small intestine was measured by intestinal transit after oral administration of a non-absorbed marker. Intraperitoneal administration of GIP inhibited glucose absorption in wild-type mice in a concentration-dependent manner, showing maximum decrease at the dosage of 50 nmol/kg body weight. In glucagon-like-peptide-1 (GLP-1) receptor-deficient mice, GIP inhibited glucose absorption as in wild-type mice. In vitro examination of [{sup 14}C]-glucose uptake revealed that 100 nM GIP did not change SGLT-dependent glucose uptake in wild-type mice. After intraperitoneal administration of GIP (50 nmol/kg body weight), small intestinal transit was inhibited to 40% in both wild-type and GLP-1 receptor-deficient mice. Furthermore, a somatostatin receptor antagonist, cyclosomatostatin, reduced the inhibitory effect of GIP on both intestinal transit and glucose absorption in wild-type mice. These results demonstrate that exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility through a somatostatin

  8. The effect of gastric inhibitory polypeptide on intestinal glucose absorption and intestinal motility in mice

    International Nuclear Information System (INIS)

    Ogawa, Eiichi; Hosokawa, Masaya; Harada, Norio; Yamane, Shunsuke; Hamasaki, Akihiro; Toyoda, Kentaro; Fujimoto, Shimpei; Fujita, Yoshihito; Fukuda, Kazuhito; Tsukiyama, Katsushi; Yamada, Yuichiro; Seino, Yutaka; Inagaki, Nobuya

    2011-01-01

    Research highlights: → Exogenous GIP inhibits intestinal motility through a somatostatin-mediated pathway. → Exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility. → The GIP-receptor-mediated action in intestine does not involve in GLP-1-mediated pathway. -- Abstract: Gastric inhibitory polypeptide (GIP) is released from the small intestine upon meal ingestion and increases insulin secretion from pancreatic β cells. Although the GIP receptor is known to be expressed in small intestine, the effects of GIP in small intestine are not fully understood. This study was designed to clarify the effect of GIP on intestinal glucose absorption and intestinal motility. Intestinal glucose absorption in vivo was measured by single-pass perfusion method. Incorporation of [ 14 C]-glucose into everted jejunal rings in vitro was used to evaluate the effect of GIP on sodium-glucose co-transporter (SGLT). Motility of small intestine was measured by intestinal transit after oral administration of a non-absorbed marker. Intraperitoneal administration of GIP inhibited glucose absorption in wild-type mice in a concentration-dependent manner, showing maximum decrease at the dosage of 50 nmol/kg body weight. In glucagon-like-peptide-1 (GLP-1) receptor-deficient mice, GIP inhibited glucose absorption as in wild-type mice. In vitro examination of [ 14 C]-glucose uptake revealed that 100 nM GIP did not change SGLT-dependent glucose uptake in wild-type mice. After intraperitoneal administration of GIP (50 nmol/kg body weight), small intestinal transit was inhibited to 40% in both wild-type and GLP-1 receptor-deficient mice. Furthermore, a somatostatin receptor antagonist, cyclosomatostatin, reduced the inhibitory effect of GIP on both intestinal transit and glucose absorption in wild-type mice. These results demonstrate that exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility through a somatostatin-mediated pathway rather

  9. Reversible end-to-end assembly of gold nanorods using a disulfide-modified polypeptide

    International Nuclear Information System (INIS)

    Walker, David A; Gupta, Vinay K

    2008-01-01

    Directing the self-assembly of colloidal particles into nanostructures is of great interest in nanotechnology. Here, reversible end-to-end assembly of gold nanorods (GNR) is induced by pH-dependent changes in the secondary conformation of a disulfide-modified poly(L-glutamic acid) (SSPLGA). The disulfide anchoring group drives chemisorption of the polyacid onto the end of the gold nanorods in an ethanolic solution. A layer of poly(vinyl pyrrolidone) is adsorbed on the positively charged, surfactant-stabilized GNR to screen the surfactant bilayer charge and provide stability for dispersion of the GNR in ethanol. For comparison, irreversible end-to-end assembly using a bidentate ligand, namely 1,6-hexanedithiol, is also performed. Characterization of the modified GNR and its end-to-end linking behavior using SSPLGA and hexanedithiol is performed using dynamic light scattering (DLS), UV-vis absorption spectroscopy and transmission electron microscopy (TEM). Experimental results show that, in a colloidal solution of GNR-SSPLGA at a pH∼3.5, where the PLGA is in an α-helical conformation, the modified GNR self-assemble into one-dimensional nanostructures. The linking behavior can be reversed by increasing the pH (>8.5) to drive the conformation of the polypeptide to a random coil and this reversal with pH occurs rapidly within minutes. Cycling the pH multiple times between low and high pH values can be used to drive the formation of the nanostructures of the GNR and disperse them in solution.

  10. Thyroid Hormones Are Transport Substrates and Transcriptional Regulators of Organic Anion Transporting Polypeptide 2B1.

    Science.gov (United States)

    Meyer Zu Schwabedissen, Henriette E; Ferreira, Celio; Schaefer, Anima M; Oufir, Mouhssin; Seibert, Isabell; Hamburger, Matthias; Tirona, Rommel G

    2018-07-01

    Levothyroxine replacement therapy forms the cornerstone of hypothyroidism management. Variability in levothyroxine oral absorption may contribute to the well-recognized large interpatient differences in required dose. Moreover, levothyroxine-drug pharmacokinetic interactions are thought to be caused by altered oral bioavailability. Interestingly, little is known regarding the mechanisms contributing to levothyroxine absorption in the gastrointestinal tract. Here, we aimed to determine whether the intestinal drug uptake transporter organic anion transporting polypeptide 2B1 (OATP2B1) may be involved in facilitating intestinal absorption of thyroid hormones. We also explored whether thyroid hormones regulate OATP2B1 gene expression. In cultured Madin-Darby Canine Kidney II/OATP2B1 cells and in OATP2B1-transfected Caco-2 cells, thyroid hormones were found to inhibit OATP2B1-mediated uptake of estrone-3-sulfate. Competitive counter-flow experiments evaluating the influence on the cellular accumulation of estrone-3-sulfate in the steady state indicated that thyroid hormones were substrates of OATP2B1. Additional evidence that thyroid hormones were OATP2B1 substrates was provided by OATP2B1-dependent stimulation of thyroid hormone receptor activation in cell-based reporter assays. Bidirectional transport studies in intestinal Caco-2 cells showed net absorptive flux of thyroid hormones, which was attenuated by the presence of the OATP2B1 inhibitor, atorvastatin. In intestinal Caco-2 and LS180 cells, but not in liver Huh-7 or HepG2 cells, OATP2B1 expression was induced by treatment with thyroid hormones. Reporter gene assays revealed thyroid hormone receptor α -mediated transactivation of the SLCO2B1 1b and the SLCO2B1 1e promoters. We conclude that thyroid hormones are substrates and transcriptional regulators of OATP2B1. These insights provide a potential mechanistic basis for oral levothyroxine dose variability and drug interactions. Copyright © 2018 by The American

  11. Isoform-specific regulation of osteogenic factors by polypeptide N-Acetylgalactosaminyltransferases 1 and 4

    International Nuclear Information System (INIS)

    Tang, Juan; Zheng, Hanxi; Chen, Ling; Gao, Shangshang; Shi, Xiaorui; Liu, Jingjing; Xu, Lan

    2017-01-01

    The family of UDP-GalNAc polypeptide: N-Acetylgalactosaminlytransfersases (ppGalNAcTs) catalyzes the initial step of O-linked protein glycosylation. Mucin-type O-glycoproteins are abundant in the bone and may play an important role in osteogenesis. Herein, we examined the effects of ppGalNAc-T isoforms on osteogenesis of MC3T3-E1 pre-osteoblasts. We found that ppGalNAc-T1 and -T4 isoforms were highly expressed during osteogenesis of MC3T3-E1 and their knockdown by short hairpin RNA (shRNA) decreased osteoblast formation and bone mineralization. Knockdown of ppGalNAc-T1 or -T4 decreased mRNA and protein levels of bone sialoprotein (BSP). Knockdown of ppGalNAc-T1decreased mRNA levels of osteocalcin (OC), osteoprotegerin (OPG). Knockdown ofppGalNAc-T4 isoform decreased mRNA levels of OC, OPG and vitamin D receptor (VDR). While knockdown of T1 or T4 isoforms did not change the expression of osteopontin (OPN), COLLI, receptor activator for nuclear factor-κB ligand (RANKL) and transforming growth factor-β (TGF-β). Our results demonstrated that the ppGalNAc-T4 was highly expressed in MC3T3-E1 cells during osteogenesis for the first time. We also found that ppGalNAc-T1 and -T4 affected the expression of different osteogenic factors, suggesting distinct roles ppGalNAc-T isoformsplay in regulating osteogenesis in vitro. - Highlights: • ppGalNAc-T1 and T4 are highly expressed during MC3T3 cell osteogenesis. • Knockdown of ppGalNAc-T1 and -T4 decreases osteogenic differentiation and mineralization. • Expression of osteogenic factors are differentially affected by decreased ppGalNAc-T1 and -T4 expression.

  12. Human Islet Amyloid Polypeptide Fibril Binding to Catalase: A Transmission Electron Microscopy and Microplate Study

    Directory of Open Access Journals (Sweden)

    Nathaniel G. N. Milton

    2010-01-01

    Full Text Available The diabetes-associated human islet amyloid polypeptide (IAPP is a 37-amino-acid peptide that forms fibrils in vitro and in vivo. Human IAPP fibrils are toxic in a similar manner to Alzheimer's amyloid-β (Aβ and prion protein (PrP fibrils. Previous studies have shown that catalase binds to Aβ fibrils and appears to recognize a region containing the Gly-Ala-Ile-Ile sequence that is similar to the Gly-Ala-Ile-Leu sequence found in human IAPP residues 24-27. This study presents a transmission electron microscopy (TEM—based analysis of fibril formation and the binding of human erythrocyte catalase to IAPP fibrils. The results show that human IAPP 1-37, 8-37, and 20-29 peptides form fibrils with diverse and polymorphic structures. All three forms of IAPP bound catalase, and complexes of IAPP 1-37 or 8-37 with catalase were identified by immunoassay. The binding of biotinylated IAPP to catalase was high affinity with a KD of 0.77nM, and could be inhibited by either human or rat IAPP 1-37 and 8-37 forms. Fibrils formed by the PrP 118-135 peptide with a Gly-Ala-Val-Val sequence also bound catalase. These results suggest that catalase recognizes a Gly-Ala-Ile-Leu—like sequence in amyloid fibril-forming peptides. For IAPP 1-37 and 8-37, the catalase binding was primarily directed towards fibrillar rather than ribbon-like structures, suggesting differences in the accessibility of the human IAPP 24-27 Gly-Ala-Ile-Leu region. This suggests that catalase may be able to discriminate between different structural forms of IAPP fibrils. The ability of catalase to bind IAPP, Aβ, and PrP fibrils demonstrates the presence of similar accessible structural motifs that may be targets for antiamyloid therapeutic development.

  13. Vibrational infrared and Raman spectra of polypeptides: Fragments-in-fragments within molecular tailoring approach

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, Nityananda; Gadre, Shridhar R., E-mail: gadre@iitk.ac.in [Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016 (India)

    2016-03-21

    The present work reports the calculation of vibrational infrared (IR) and Raman spectra of large molecular systems employing molecular tailoring approach (MTA). Further, it extends the grafting procedure for the accurate evaluation of IR and Raman spectra of large molecular systems, employing a new methodology termed as Fragments-in-Fragments (FIF), within MTA. Unlike the previous MTA-based studies, the accurate estimation of the requisite molecular properties is achieved without performing any full calculations (FC). The basic idea of the grafting procedure is implemented by invoking the nearly basis-set-independent nature of the MTA-based error vis-à-vis the respective FCs. FIF has been tested out for the estimation of the above molecular properties for three isomers, viz., β-strand, 3{sub 10}- and α-helix of acetyl(alanine){sub n}NH{sub 2} (n = 10, 15) polypeptides, three conformers of doubly protonated gramicidin S decapeptide and trpzip2 protein (PDB id: 1LE1), respectively, employing BP86/TZVP, M06/6-311G**, and M05-2X/6-31G** levels of theory. For most of the cases, a maximum difference of 3 cm{sup −1} is achieved between the grafted-MTA frequencies and the corresponding FC values. Further, a comparison of the BP86/TZVP level IR and Raman spectra of α-helical (alanine){sub 20} and its N-deuterated derivative shows an excellent agreement with the existing experimental spectra. In view of the requirement of only MTA-based calculations and the ability of FIF to work at any level of theory, the current methodology provides a cost-effective solution for obtaining accurate spectra of large molecular systems.

  14. Unraveling origins of the heterogeneous curvature dependence of polypeptide interactions with carbon nanostructures.

    Science.gov (United States)

    Jana, Asis K; Tiwari, Mrityunjay K; Vanka, Kumar; Sengupta, Neelanjana

    2016-02-17

    Emerging nanotechnology has rapidly broadened interfacial prospects of biological molecules with carbon nanomaterials (CNs). A prerequisite for effectively harnessing such hybrid materials is a multi-faceted understanding of their complex interfacial interactions as functions of the physico-chemical characteristics and the surface topography of the individual components. In this article, we address the origins of the curvature dependence of polypeptide adsorption on CN surfaces (CNSs), a phenomenon bearing an acute influence upon the behavior and activity of CN-protein conjugates. Our benchmark molecular dynamics (MD) simulations with the amphiphilic full-length amyloid beta (Aβ) peptide demonstrate that protein adsorption is strongest on the concave (inner) CN surface, weakest on the convex (outer) surface, and intermediary on the planar surface, in agreement with recent experimental reports. The curvature effects, however, are found to manifest non-uniformly between the amino acid subtypes. To understand the underlying interplay of the chemical nature of the amino acids and surface topography of the CNs, we performed high-level quantum chemical (QM) calculations with amino acid analogs (AAA) representing their five prominent classes, and convex, concave and planar CN fragments. Molecular electrostatic potential maps reveal pronounced curvature dependence in the mixing of electron densities, and a resulting variance in the stabilization of the non-covalently bound molecular complexes. Interestingly, our study revealed that the interaction trends of the high-level QM calculations were captured well by the empirical force field. The findings in this study have important bearing upon the design of carbon based bio-nanomaterials, and additionally, provide valuable insights into the accuracy of various computational techniques for probing non-bonded interfacial interactions.

  15. A New in Vitro Anti-Tumor Polypeptide Isolated from Arca inflata

    Directory of Open Access Journals (Sweden)

    Jian Xu

    2013-12-01

    Full Text Available A new in vitro anti-tumor polypeptide, coded as J2-C3, was isolated from Arca inflata Reeve and purified by diethyl-aminoethanol (DEAE-sepharose Fast Flow anion exchange and phenyl sepharose CL-4B hydrophobic chromatography. J2-C3 was identified to be a homogeneous compound by native polyacrylamide gel electrophoresis (Native-PAGE. The purity of J2-C3 was over 99% in reversed phase-high performance liquid chromatography (RP-HPLC. The molecular weight was determined as 20,538.0 Da by electrospray-ionization mass spectrometry (ESI-MS/MS. J2-C3 was rich in Glx (Gln + Glu, Lys, and Asx (Asp + Asn according to amino acid analysis. Four partial amino acid sequences of this peptide were determined as L/ISMEDVEESR, KNGMHSI/LDVNHDGR, AMKI/LI/LNPKKGI/LVPR and AMGAHKPPKGNEL/IGHR via MALDI-TOF/TOF-MS and de novo sequencing. Secondary structural analysis by CD spectroscopy revealed that J2-C3 had the α-helix (45.2%, β-sheet (2.9%, β-turn (26.0% and random coil (25.9%. The anti-tumor effect of J2-C3 against human tumor cells was measured by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay, and the IC50 values of J2-C3 were 65.57, 93.33 and 122.95 µg/mL against A549, HT-29 and HepG2 cell lines, respectively. Therefore, J2-C3 might be developed as a potential anti-tumor agent.

  16. Drosophila Melanogaster as a Model System for Studies of Islet Amyloid Polypeptide Aggregation

    Science.gov (United States)

    Schultz, Sebastian Wolfgang; Nilsson, K. Peter R.; Westermark, Gunilla Torstensdotter

    2011-01-01

    Background Recent research supports that aggregation of islet amyloid polypeptide (IAPP) leads to cell death and this makes islet amyloid a plausible cause for the reduction of beta cell mass, demonstrated in patients with type 2 diabetes. IAPP is produced by the beta cells as a prohormone, and proIAPP is processed into IAPP by the prohormone convertases PC1/3 and PC2 in the secretory granules. Little is known about the pathogenesis for islet amyloid and which intracellular mechanisms are involved in amyloidogenesis and induction of cell death. Methodology/Principal Findings We have established expression of human proIAPP (hproIAPP), human IAPP (hIAPP) and the non-amyloidogenic mouse IAPP (mIAPP) in Drosophila melanogaster, and compared survival of flies with the expression driven to different cell populations. Only flies expressing hproIAPP in neurons driven by the Gal4 driver elavC155,Gal4 showed a reduction in lifespan whereas neither expression of hIAPP or mIAPP influenced survival. Both hIAPP and hproIAPP expression caused formation of aggregates in CNS and fat body region, and these aggregates were both stained by the dyes Congo red and pFTAA, both known to detect amyloid. Also, the morphology of the highly organized protein granules that developed in the fat body of the head in hIAPP and hproIAPP expressing flies was characterized, and determined to consist of 15.8 nm thick pentagonal rod-like structures. Conclusions/Significance These findings point to a potential for Drosophila melanogaster to serve as a model system for studies of hproIAPP and hIAPP expression with subsequent aggregation and developed pathology. PMID:21695120

  17. Pituitary adenylate cyclase-activating polypeptide stimulates glucose production via the hepatic sympathetic innervation in rats.

    Science.gov (United States)

    Yi, Chun-Xia; Sun, Ning; Ackermans, Mariette T; Alkemade, Anneke; Foppen, Ewout; Shi, Jing; Serlie, Mireille J; Buijs, Ruud M; Fliers, Eric; Kalsbeek, Andries

    2010-07-01

    The unraveling of the elaborate brain networks that control glucose metabolism presents one of the current challenges in diabetes research. Within the central nervous system, the hypothalamus is regarded as the key brain area to regulate energy homeostasis. The aim of the present study was to investigate the hypothalamic mechanism involved in the hyperglycemic effects of the neuropeptide pituitary adenylyl cyclase-activating polypeptide (PACAP). Endogenous glucose production (EGP) was determined during intracerebroventricular infusions of PACAP-38, vasoactive intestinal peptide (VIP), or their receptor agonists. The specificity of their receptors was examined by coinfusions of receptor antagonists. The possible neuronal pathway involved was investigated by 1) local injections in hypothalamic nuclei, 2) retrograde neuronal tracing from the thoracic spinal cord to hypothalamic preautonomic neurons together with Fos immunoreactivity, and 3) specific hepatic sympathetic or parasympathetic denervation to block the autonomic neuronal input to liver. Intracerebroventricular infusion of PACAP-38 increased EGP to a similar extent as a VIP/PACAP-2 (VPAC2) receptor agonist, and intracerebroventricular administration of VIP had significantly less influence on EGP. The PACAP-38 induced increase of EGP was significantly suppressed by preinfusion of a VPAC2 but not a PAC1 receptor antagonist, as well as by hepatic sympathetic but not parasympathetic denervation. In the hypothalamus, Fos immunoreactivity induced by PACAP-38 was colocalized within autonomic neurons in paraventricular nuclei projecting to preganglionic sympathetic neurons in the spinal cord. Local infusion of PACAP-38 directly into the PVN induced a significant increase of EGP. This study demonstrates that PACAP-38 signaling via sympathetic preautonomic neurons located in the paraventricular nucleus is an important component in the hypothalamic control of hepatic glucose production.

  18. Diagnostic value of tissue polypeptide specific antigen in serum for patients with pancreatic carcinoma

    International Nuclear Information System (INIS)

    Lu Yun; Liu Xingdang; Li Ding; Dei Shouzhen

    2009-01-01

    Objective: To compare the diagnostic value of tissue polypeptide specific antigen (TPS) in serum, with the carbohydrate antigens (CA) 19-9, CA50, CA125 and CA242 in pancreatic carcinoma. Methods: Serum TPS was measured with enzyme linked immunosorbent assay (ELISA). CA19-9 and CA125 were measured with chemiluminescent immunoassay. CAS0 and CA242 were measured with immunoradiometric assay in 33 patients with pancreatitis, 34 patients with pathologically proven pancreatic carcinoma, and 35 patients with non-pancreatic malignancies. Statistic analysis was carried out with SPSS 9.0 software. Results: Patients with pancreatic carcinoma had relatively higher levels of TPS [(386.5 ± 315. 1) U/L] and CA19-9 [(10 820.9 ± 389.7) kU/L] when compared with patients with pancreatitis [(86. 2 ± 28.1) U/L and (61.5 ± 24.7) kU/L, respectively; F = 936. 42, P < 0. 001 ; F = 2217. 09, P < 0. 001], with a sensitivity and a specificity of 70.6% (48/68) and 57.4% (39/68), respectively, for TPS, and 82.4% (28/34) and 77.9% (53/68), respectively, for CA19-9. Diagnostic performance was further improved when TPS was assayed in combination with CA19-9, CA50, CA125 and CA242. Conclusion: Serum TPS has an incremental value in complementing CA19-9 in the diagnosis of pancreatic carcinoma. (authors)

  19. [Clinico-pathogenetic variants of chronic gastritis].

    Science.gov (United States)

    Chernin, V V; Dzhulaĭ, G S

    2004-01-01

    To evaluate specific features of the course of chronic gastritis (CG), morphofunctional condition of gastric mucosa, vegetative regulation, adrenergic and cholinergic shifts, histamine metabolism and effects of exogenic and endogenic risk factors in CG patients; to study clinicopathogenetic variants of CG. A total of 311 CG patients aged from 16 to 72 years were studied. They were divided into three groups by their gastric mucosa condition. The control group consisted of 30 healthy donors. The following parameters were studied: visual and histological condition of gastric mucosa, total acidity, the levels of free hydrochloric acid, pepsin, bioelectric gastric activity, general autonomic tonicity, cholinesterase activity. Three clinicopathogenetic variants of the disease have been identified. Variant 1 was characterized by a recurrent course, subjective manifestation of the disease only in exacerbation, surface (primarily antral) mucosal affection, normal or enhanced secretory and motor functions of the stomach, adequate reaction of acid production to caffeine and histamine stimulation, parasympathicotonia, absolute hyperhistaminemia, relative hypoacetylcholinemia, subnormal urinary excretion of adrenalin. Variant 2 manifested with rare recurrences, longer and more severe exacerbations, frequent spontaneous and provoked aggravations, moderate focal atrophy of the mucosa, secretory insufficiency with adequate reaction to histamine and minor to caffeine stimuli, hypomotor gastric dyskinesia, vegetative eutonia, normohistaminemia, absolute hypoacetylcholinemia, subnormal urinary excretion of noradrenaline. Variant 3 runs without definite remissions and exacerbations, with continuous abdominal pain and dyspepsia, frequent spontaneous aggravations, marked extended mucosal atrophy with secretory insufficiency up to achlorhydria, no stimulation of acid production in response to caffeine and histamine, gastric hypomotility, sympathicotonia, absolute hypohistaminemia

  20. Normal variants of skin in neonates

    Directory of Open Access Journals (Sweden)

    Kulkarni M

    1996-01-01

    Full Text Available 2221 consecutive live births taking place between March 1994 and February 1995 were evaluated for a minimum period of 5 days to note for the occurrence of various normal anatomical variants specially those of skin. Birth weight, gestational age, maternal age, socio-economic status and consanguinity were carefully recorded in all the cases. Mongolian spots (72%, Epstein pearls (43.8%, Milia (26.2% and Erythema toxicum (25.2%, were the common dermatological variants noted. Maturity of the babies and possibly genetic factors (consanguinity are important factors in their causation as ordered in our study.

  1. The curation of genetic variants: difficulties and possible solutions.

    Science.gov (United States)

    Pandey, Kapil Raj; Maden, Narendra; Poudel, Barsha; Pradhananga, Sailendra; Sharma, Amit Kumar

    2012-12-01

    The curation of genetic variants from biomedical articles is required for various clinical and research purposes. Nowadays, establishment of variant databases that include overall information about variants is becoming quite popular. These databases have immense utility, serving as a user-friendly information storehouse of variants for information seekers. While manual curation is the gold standard method for curation of variants, it can turn out to be time-consuming on a large scale thus necessitating the need for automation. Curation of variants described in biomedical literature may not be straightforward mainly due to various nomenclature and expression issues. Though current trends in paper writing on variants is inclined to the standard nomenclature such that variants can easily be retrieved, we have a massive store of variants in the literature that are present as non-standard names and the online search engines that are predominantly used may not be capable of finding them. For effective curation of variants, knowledge about the overall process of curation, nature and types of difficulties in curation, and ways to tackle the difficulties during the task are crucial. Only by effective curation, can variants be correctly interpreted. This paper presents the process and difficulties of curation of genetic variants with possible solutions and suggestions from our work experience in the field including literature support. The paper also highlights aspects of interpretation of genetic variants and the importance of writing papers on variants following standard and retrievable methods. Copyright © 2012. Published by Elsevier Ltd.

  2. A pH- and temperature-responsive bioresorbable injectable hydrogel based on polypeptide block copolymers for the sustained delivery of proteins in vivo.

    Science.gov (United States)

    Turabee, Md Hasan; Thambi, Thavasyappan; Duong, Huu Thuy Trang; Jeong, Ji Hoon; Lee, Doo Sung

    2018-02-27

    Sustained delivery of protein therapeutics is limited owing to the fragile nature of proteins. Despite its great potential, delivery of proteins without any loss of bioactivity remains a challenge in the use of protein therapeutics in the clinic. To surmount this shortcoming, we report a pH- and temperature-responsive in situ-forming injectable hydrogel based on comb-type polypeptide block copolymers for the controlled delivery of proteins. Polypeptide block copolymers, composed of hydrophilic polyethylene glycol (PEG), temperature-responsive poly(γ-benzyl-l-glutamate) (PBLG), and pH-responsive oligo(sulfamethazine) (OSM), exhibit pH- and temperature-induced sol-to-gel transition behavior in aqueous solutions. Polypeptide block copolymers were synthesized by combining N-carboxyanhydride-based ring-opening polymerization and post-functionalization of the chain-end using N-hydroxy succinimide ester activated OSM. The physical properties of polypeptide-based hydrogels were tuned by varying the composition of temperature- and pH-responsive PBLG and OSM in block copolymers. Polypeptide block copolymers were non-toxic to human embryonic kidney cells at high concentrations (2000 μg mL -1 ). Subcutaneous administration of polypeptide block copolymer sols formed viscoelastic gel instantly at the back of Sprague-Dawley (SD) rats. The in vivo gels exhibited sustained degradation and were found to be bioresorbable in 6 weeks without any noticeable inflammation at the injection site. Anionic characteristics of hydrogels allow efficient loading of a cationic model protein, lysozyme, through electrostatic interaction. Lysozyme-loaded polypeptide block copolymer sols readily formed a viscoelastic gel in vivo and sustained lysozyme release for at least a week. Overall, the results demonstrate an elegant approach to control the release of certain charged proteins and open a myriad of therapeutic possibilities in protein therapeutics.

  3. Comparative analysis of the folding dynamics and kinetics of an engineered knotted protein and its variants derived from HP0242 of Helicobacter pylori

    Science.gov (United States)

    Wang, Liang-Wei; Liu, Yu-Nan; Lyu, Ping-Chiang; Jackson, Sophie E.; Hsu, Shang-Te Danny

    2015-09-01

    Understanding the mechanism by which a polypeptide chain thread itself spontaneously to attain a knotted conformation has been a major challenge in the field of protein folding. HP0242 is a homodimeric protein from Helicobacter pylori with intertwined helices to form a unique pseudo-knotted folding topology. A tandem HP0242 repeat has been constructed to become the first engineered trefoil-knotted protein. Its small size renders it a model system for computational analyses to examine its folding and knotting pathways. Here we report a multi-parametric study on the folding stability and kinetics of a library of HP0242 variants, including the trefoil-knotted tandem HP0242 repeat, using far-UV circular dichroism and fluorescence spectroscopy. Equilibrium chemical denaturation of HP0242 variants shows the presence of highly populated dimeric and structurally heterogeneous folding intermediates. Such equilibrium folding intermediates retain significant amount of helical structures except those at the N- and C-terminal regions in the native structure. Stopped-flow fluorescence measurements of HP0242 variants show that spontaneous refolding into knotted structures can be achieved within seconds, which is several orders of magnitude faster than previously observed for other knotted proteins. Nevertheless, the complex chevron plots indicate that HP0242 variants are prone to misfold into kinetic traps, leading to severely rolled-over refolding arms. The experimental observations are in general agreement with the previously reported molecular dynamics simulations. Based on our results, kinetic folding pathways are proposed to qualitatively describe the complex folding processes of HP0242 variants.

  4. Magnetic resonance angiography: infrequent anatomic variants

    International Nuclear Information System (INIS)

    Trejo, Mariano; Meli, Francisco; Lambre, Hector; Blessing, Ricardo; Gigy Traynor, Ignacio; Miguez, Victor

    2002-01-01

    We studied through RM angiography (3D TOF) with high magnetic field equipment (1.5 T) different infrequent intracerebral vascular anatomic variants. For their detection we emphasise the value of post-processed images obtained after conventional angiographic sequences. These post-processed images should be included in routine protocols for evaluation of the intracerebral vascular structures. (author)

  5. Report of a rare anatomic variant

    DEFF Research Database (Denmark)

    De Brucker, Y; Ilsen, B; Muylaert, C

    2015-01-01

    We report the CT findings in a case of partial anomalous pulmonary venous return (PAPVR) from the left upper lobe in an adult. PAPVR is an anatomic variant in which one to three pulmonary veins drain into the right atrium or its tributaries, rather than into the left atrium. This results in a left...

  6. Analysis of the energy development variants

    International Nuclear Information System (INIS)

    Tsvetanov, P.

    1990-01-01

    Analysis of the variants of energy development is made as the third stage of a procedure of energy-economy interrelations dynamics study, the other two stages being the scenarios description and the formulation of the variants. This stage includes a research on the dimensions and the dynamics of the resources demands, the general features and the trends of the national energy development. There is a presentation of a comparative analysis of the variants in terms of economic indices and energy values, computed by the model IMPACT-B. A resource evaluation of the development variants is given in terms of investments, requirements (direct, indirect and total) and limited national resources demands of the energy system. The trends of the national energy development discussed are: trends characterizing the changes in the structure of the energy consumption, resulting from changes in the economy; trends of the energy system impact on the productivity of labor; general trends of the proportionality in the industrial, the household and services sector development. 16 refs., 16 figs., 4 tabs. (R.Ts.)

  7. Cellobiohydrolase I gene and improved variants

    Science.gov (United States)

    Adney, William S [Golden, CO; Decker, Stephen R [Berthoud, CO; Mc Carter, Suzanne [San Carlos, CA; Baker, John O [Golden, CO; Nieves, Raphael [Lakewood, CO; Himmel, Michael E [Littleton, CO; Vinzant, Todd B [Golden, CO

    2008-05-20

    The disclosure provides a method for preparing an active exoglucanase in a heterologous host of eukaryotic origin. The method includes mutagenesis to reduce glycosylation of the exoglucanase when expressed in a heterologous host. It is further disclosed a method to produce variant cellobiohydrolase that is stable at high temperature through mutagenesis.

  8. XVCL: XML-based Variant Configuration Language

    DEFF Research Database (Denmark)

    Jarzabek, Stan; Basset, Paul; Zhang, Hongyu

    2003-01-01

    XVCL (XML-based Variant Configuration Language) is a meta-programming technique and tool that provides effective reuse mechanisms. XVCL is an open source software developed at the National University of Singapore. Being a modern and versatile version of Bassett's frames, a technology that has...

  9. Glucose 6-phosphate dehydrogenase variants in Japan.

    Science.gov (United States)

    Miwa, S

    1980-01-01

    Fifty-four cases of glucose 6-phosphate dehydrogenase (G6PD) deficiency have so far been reported in Japan. Among them, 21 G6PD variants have been characterized. Nineteen out of the 21 variants were characterized in our laboratory and G6PD Heian and "Kyoto" by others. G6PD Tokyo, Tokushima, Ogikubo, Kurume, Fukushima, Yokohama, Yamaguchi, Wakayama, Akita, Heian and "Kyoto" were classified as Class 1, because all these cases showed chronic hemolytic anemia and severe enzyme deficiency. All these variants showed thermal instability. G6PD Mediterranean-like, Ogori, Gifu and Fukuoka were classified as Class 2, whereas G6PD Hofu, B(-) Chinese, Ube, Konan, Kamiube and Kiwa belonged to Class 3. All the 6 Class 3 variants were found as the results of the screening tests. The incidence of the deficiency in Japanese seems to be 0.1-0.5% but that of the cases which may slow drug-induced hemolysis would be much less. G6PD Ube and Konan appear to be relatively common in Japan.

  10. Genetic variants influencing phenotypic variance heterogeneity.

    Science.gov (United States)

    Ek, Weronica E; Rask-Andersen, Mathias; Karlsson, Torgny; Enroth, Stefan; Gyllensten, Ulf; Johansson, Åsa

    2018-03-01

    Most genetic studies identify genetic variants associated with disease risk or with the mean value of a quantitative trait. More rarely, genetic variants associated with variance heterogeneity are considered. In this study, we have identified such variance single-nucleotide polymorphisms (vSNPs) and examined if these represent biological gene × gene or gene × environment interactions or statistical artifacts caused by multiple linked genetic variants influencing the same phenotype. We have performed a genome-wide study, to identify vSNPs associated with variance heterogeneity in DNA methylation levels. Genotype data from over 10 million single-nucleotide polymorphisms (SNPs), and DNA methylation levels at over 430 000 CpG sites, were analyzed in 729 individuals. We identified vSNPs for 7195 CpG sites (P mean DNA methylation levels. We further showed that variance heterogeneity between genotypes mainly represents additional, often rare, SNPs in linkage disequilibrium (LD) with the respective vSNP and for some vSNPs, multiple low frequency variants co-segregating with one of the vSNP alleles. Therefore, our results suggest that variance heterogeneity of DNA methylation mainly represents phenotypic effects by multiple SNPs, rather than biological interactions. Such effects may also be important for interpreting variance heterogeneity of more complex clinical phenotypes.

  11. Genetic variants associated with lung function

    DEFF Research Database (Denmark)

    Thyagarajan, Bharat; Wojczynski, Mary; Minster, Ryan L

    2014-01-01

    with exceptional longevity have not been identified. METHOD: We conducted a genome wide association study (GWAS) to identify novel genetic variants associated with lung function in the Long Life Family Study (LLFS) (n = 3,899). Replication was performed using data from the CHARGE/SpiroMeta consortia...

  12. Genetic variants in NTCP exon gene are associated with HBV infection status in a Chinese Han population.

    Science.gov (United States)

    Wu, Wennan; Zeng, Yongbin; Lin, Jinpiao; Wu, Yingying; Chen, Tianbin; Xun, Zhen; Ou, Qishui

    2018-04-01

    Sodium taurocholate co-transporting polypeptide (NTCP) plays an important role in the enterohepatic circulation of bile acids. Recently, NTCP was identified as a hepatitis B virus (HBV) receptor. The aim of this study is to investigate the association of NTCP polymorphisms with HBV clinical outcomes and investigate the relationship between NTCP polymorphisms and the serum bile acid level in a Chinese Han population. The single nucleotide polymorphisms rs2296651 and rs4646285 were genotyped in 1619 Chinese Han individuals. Improved multiple ligase detection reaction was utilized to genotype. The level of bile acids was measured by the enzymatic cycling method. Quantitative polymerase chain reaction analysis was carried out to analyze the potential function. In logistic regression analysis, the frequency of rs2296651 (S267F) CT genotype was higher in HBV immune recovery and healthy control groups than in the chronic HBV infection group (P = 0.001 and P HBV infection group (P = 0.011). No difference in serum bile acid was detected between the rs4646285 wild-type patients and mutant-type patients. Quantitative reverse transcription-polymerase chain reaction showed the NTCP mRNA levels were lower in rs4646285 variants than wild types. NTCP gene polymorphisms may be associated with the natural course of HBV infection in a Chinese Han population. The S267F variant may be a protective factor to resist chronic hepatitis B progression which showed a higher bile acid level in Chinese Han chronic HBV infection patients. The rs4646285 variants could influence the expression of NTCP at the level of transcription, and ultimately may be associated with HBV infection immune recovery. © 2017 The Japan Society of Hepatology.

  13. Effect of double-tailed surfactant architecture on the conformation, self-assembly, and processing in polypeptide-surfactant complexes.

    Science.gov (United States)

    Junnila, Susanna; Hanski, Sirkku; Oakley, Richard J; Nummelin, Sami; Ruokolainen, Janne; Faul, Charl F J; Ikkala, Olli

    2009-10-12

    This work describes the solid-state conformational and structural properties of self-assembled polypeptide-surfactant complexes with double-tailed surfactants. Poly(L-lysine) was complexed with three dialkyl esters of phosphoric acid (i.e., phosphodiester surfactants), where the surfactant tail branching and length was varied to tune the supramolecular architecture in a facile way. After complexation with the branched surfactant bis(2-ethylhexyl) phosphate in an aqueous solution, the polypeptide chains adopted an alpha-helical conformation. These rod-like helices self-assembled into cylindrical phases with the amorphous alkyl tails pointing outward. In complexes with dioctyl phosphate and didodecyl phosphate, which have two linear n-octyl or n-dodecyl tails, respectively, the polypeptide formed antiparallel beta-sheets separated by alkyl layers, resulting in well-ordered lamellar self-assemblies. By heating, it was possible to trigger a partial opening of the beta-sheets and disruption of the lamellar phase. After repeated heating/cooling, all of these complexes also showed a glass transition between 37 and 50 degrees C. Organic solvent treatment and plasticization by overstoichiometric amount of surfactant led to structure modification in poly(L-lysine)-dioctyl phosphate complexes, PLL(diC8)(x) (x = 1.0-3.0). Here, the alpha-helical PLL is surrounded by the surfactants and these bottle-brush-like chains self-assemble in a hexagonal cylindrical morphology. As x is increased, the materials are clearly plasticized and the degree of ordering is improved: The stiff alpha-helical backbones in a softened surfactant matrix give rise to thermotropic liquid-crystalline phases. The complexes were examined by Fourier transform infrared spectroscopy, small- and wide-angle X-ray scattering, transmission electron microscopy, differential scanning calorimetry, polarized optical microscopy, and circular dichroism.

  14. Design and synthesis of elastin-like polypeptides for an ideal nerve conduit in peripheral nerve regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Hsueh, Yu-Sheng [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China); Savitha, S. [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); Department of Biotechnology, Sree Sastha Institute of Engineering and Technology, Chennai (India); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China); Sadhasivam, S. [Division of Biomedical Engineering and Nanomedicine Research, National Health Research Institutes, Miaoli 350, Taiwan (China); Lin, Feng-Huei, E-mail: double@ntu.edu.tw [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); Division of Biomedical Engineering and Nanomedicine Research, National Health Research Institutes, Miaoli 350, Taiwan (China); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China); Shieh, Ming-Jium [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); College of Medicine, National Taiwan University Hospital, Taipei 100, Taiwan (China); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China)

    2014-05-01

    The study involves design and synthesis of three different elastin like polypeptide (ELP) gene monomers namely ELP1, ELP2 and ELP3 that encode for ELP proteins. The formed ELPs were assessed as an ideal nerve conduit for peripheral nerve regeneration. ELP1 was constructed with a small elongated pentapeptide carrying VPGVG sequence to mimic the natural polypeptide ELP. The ELP2 was designed by the incorporation of 4-penta peptide chains to improve the biocompatibility and mechanical strength. Thus, the third position in unique VPGVG was replaced with alanine to VPAVG and in a similar way modified to VPGKG, VPGEG and VPGIG with the substitution of lysine, glutamic acid and isoleucine. In ELP3, fibronectin C5 domain endowed with REDV sequence was introduced to improve the cell attachment. The ELP1, ELP2 and ELP3 proteins expressed by Escherichia coli were purified by inverse transition cycling (ITC). The purified ELPs were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting. The Schwann cell (SC) morphology and cell adhesion were assessed by fabrication of ELP membrane cross-linked with glutaraledhyde. The Schwann cell proliferation was measured by WST-1 assay. Immunofluorostaining of Schwann cells was accomplished with SC specific phenotypic marker, S100. - Highlights: • Design and synthesis of three gene monomers of elastin like polypeptides (ELP1, 2 and 3) were reported. • Molecular weight of ITC purified ELP1, ELP2 and ELP3 was in the range of 37–38 kDa. • Schwann cell adhesion was found to be prominent in ELP3 and could be used as nerve conduit for peripheral nerve regeneration.

  15. INTERACTION BETWEEN DIFFERENT MOLECULAR FORMS OF IMMUNOGLOBULIN A AND RECOMBINANT DERIVATIVES POLYPEPTIDES OF BAC RECEPTOR PROTEINS FROM GROUP B STREPTOCOCCI

    Directory of Open Access Journals (Sweden)

    A. S. Korzhueva

    2008-01-01

    Full Text Available Abstract. The article concerns interactions between immunoglobulin A and recombinant P6, P7, P8 polypeptides, designed on the basis of externally localized Bac protein of the Group B streptococci, possessing IgA-binding activity.There is a current demand for immunochemical reagents that are strictly specific for IgA, in order to develop antigenic standards for detection of IgA levels in biological fluids, as well as for affinity purification of IgA and its fragments.To analyze an opportunity of the abovementioned application ways for these proteins, a special study was performed to assay an interaction capability of recombinant P6, P7, P8 polypeptides binding to Fc regions of different IgA forms (serum IgA, secretory IgA, subclasses of serum IgA – IgA1, IgA2. Selectivity of ligand binding was specially confirmed.It was found out that, among three presented polypeptides, the structure of recombinant P6 derivative proved to be optimal for IgA-binding ability of Bac protein.Structural features of IgA-binding fragments of Bac protein, i.e., binding site position on the IgA molecule (proximity to epitopes for three monoclonal antibodies, variability of the site structure, as well as resistance of binding site for P6, P7, P8 in IgA molecule against partial disulfide bonds reduction. (Med. Immunol., vol. 10, N 4-5, pp 327-336.

  16. Iodine and tritium labelling of curarizing and cardiotoxic agents. Study of the conformation of toxic polypeptides extracted from snake venom

    International Nuclear Information System (INIS)

    Menez, Andre.

    1977-01-01

    A short review of present-day knowledge on the action mechanism of toxic snake venom polypeptides is followed by a study of the radioactive labelling of some toxic compounds. Those dealt with more especially are Naja nigricollis α toxin and Laticauda semifasciata b erabutoxin, then (+) tubocurarin, a non-peptidic curarizing alkaloid, and two cardiotoxic polypeptides: cytotoxin II and cardiotoxin γ extracted from the venom of Naja naja and Naja nigricollis respectively. The labelling principle is based on the specific fixation of one or more iodine atoms then tritium substitution of the halogen by catalytic hydrogenolysis. As predicted from titration of the aromatic groups the halogenation process, obtained by addition of iodine monochloride, takes place sometimes on the phenolic nuclei and sometimes on the imidazole nuclei, the position of which targets within each sequence has been identified. From results of the study of reactivity towards iodine combined with those of basic titration, the accessibility of several aromatic nuclei has also been defined. Each iodinated polypeptide is then hydrogenolysed in the presence of tritium gas giving a specific activity between 4 and 27 Ci/mmole according to the compound treated. In all cases the biological potential and physical properties of the radioactive material obtained by the above titration process remained intact. An example of the bonding kinetics of short toxins with the partially purified choligenic receptor is given in the special case of tritiated b erabutoxin. The affinity of this toxin for its receptor target is strong, though slightly less so than that of tritiated Naja nigricollis α toxin [fr

  17. Design and synthesis of elastin-like polypeptides for an ideal nerve conduit in peripheral nerve regeneration

    International Nuclear Information System (INIS)

    Hsueh, Yu-Sheng; Savitha, S.; Sadhasivam, S.; Lin, Feng-Huei; Shieh, Ming-Jium

    2014-01-01

    The study involves design and synthesis of three different elastin like polypeptide (ELP) gene monomers namely ELP1, ELP2 and ELP3 that encode for ELP proteins. The formed ELPs were assessed as an ideal nerve conduit for peripheral nerve regeneration. ELP1 was constructed with a small elongated pentapeptide carrying VPGVG sequence to mimic the natural polypeptide ELP. The ELP2 was designed by the incorporation of 4-penta peptide chains to improve the biocompatibility and mechanical strength. Thus, the third position in unique VPGVG was replaced with alanine to VPAVG and in a similar way modified to VPGKG, VPGEG and VPGIG with the substitution of lysine, glutamic acid and isoleucine. In ELP3, fibronectin C5 domain endowed with REDV sequence was introduced to improve the cell attachment. The ELP1, ELP2 and ELP3 proteins expressed by Escherichia coli were purified by inverse transition cycling (ITC). The purified ELPs were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting. The Schwann cell (SC) morphology and cell adhesion were assessed by fabrication of ELP membrane cross-linked with glutaraledhyde. The Schwann cell proliferation was measured by WST-1 assay. Immunofluorostaining of Schwann cells was accomplished with SC specific phenotypic marker, S100. - Highlights: • Design and synthesis of three gene monomers of elastin like polypeptides (ELP1, 2 and 3) were reported. • Molecular weight of ITC purified ELP1, ELP2 and ELP3 was in the range of 37–38 kDa. • Schwann cell adhesion was found to be prominent in ELP3 and could be used as nerve conduit for peripheral nerve regeneration

  18. Enamel formation in vitro in mouse molar explants exposed to amelogenin polypeptides ATMP and LRAP on enamel development.

    Science.gov (United States)

    Ravindranath, Rajeswari M H; Devarajan, Asokan; Bringas, Pablo

    2007-12-01

    The enamel matrix contains amelogenin, leucine-rich amelogenin-polypeptide (LRAP), resulting from alternative splicing of the primary amelogenin-RNA transcript and tyrosine-rich amelogenin-polypeptide (TRAP), a proteolytic product of amelogenin. Presence of amelogenin-trityrosyl-motif peptide (ATMP) distinguishes TRAP from LRAP. The roles of these polypeptides in the formation of enamel remain to be elucidated. The mouse in vitro molar tooth-organ developed from bud stage (E16) was exposed to LRAP, ATMP, and mutated ATMP (T-ATMP, third proline replaced by threonine). The histology and morphometry of the explants on day-12 in culture was examined using Mallory's stain. Guanidine-HCl soluble protein concentrations of explants were compared. The enamel width and protein solubility indicate that the explant on day-12 is comparable to postnatal molar on day-3 in vivo. The enamel of both untreated explants as well as that in vivo is fuchinophilic (acid fuchsin, AF+). ATMP reduced the ameloblast-height, accumulated AF+ spherules at the apical end of ameloblasts, and disrupted enamel-dentin bonding. T-ATMP abrogated deposition of AF+ material on the aniline blue positive (AB+) enamel matrix. LRAP reduced ameloblast-height, increased the enamel-width without disruption (at 17.25 nmol) and increased the density of AF+ dentinal tubules. AF+ substance from the tubules is released onto the surface of the dentin. The Guanidine-HCl-soluble protein is elevated in ATMP-treated explants but decreased in LRAP-treated explants. Exogenous ATMP, T-ATMP and LRAP have divergent effects on developing enamel. Exogenous ATMP, but not LRAP, abrogates enamel-dentin bonding at 17.25 nmol. LRAP may play a role in the differentiation of ameloblasts, growth of enamel and formation of dentinal tubules.

  19. Role of pancreatic polypeptide as a market of transplanted insulin-producing fetal pig cells.

    Science.gov (United States)

    Tuch, B E; Tabiin, M T; Casamento, F M; Yao, M; Georges, P; Amaratunga, A; Pinto, A N

    2001-01-01

    Transplantation of insulin-producing fetal pancreatic tissue into diabetic recipients has been shown to normalize blood glucose levels after several months. This time period is required for the growth and maturation of the fetal tissue so insulin levels cannot be used as a marker of graft function while the beta-cell is immature. Therefore, we have examined the use of another pancreatic endocrine hormone, pancreatic polypeptide (PP), to monitor graft function. The cell that produces this hormone has been shown to be the first mature endocrine cell in the fetal pancreas. Fetal pig pancreatic tissue, both in the form of 1 mm3 explants and islet-like cell clusters (ICCs), was transplanted into immunodeficient SCID mice and the levels of PP and insulin were measured in plasma and in the graft for up to 12 weeks. PP was detected in the untransplanted explants (0.58 pmol/mg) and ICCs (0.06 pmol/ICC) and the PP to insulin ratio was 2.7% and 5.8%, respectively. PP (but not porcine C-peptide, a marker of insulin secretion) was detectable in the plasma of SCID mice from 4 days to 3 weeks after transplantation, but not thereafter. The highest values were obtained at 4 days to 1 week. In the grafted tissue PP and insulin were present at all time points and the ratio of PP to insulin was 59%, 87%, 75%, 56%, 7%, 8%, and 7% at 4 days, 1, 2, 3, 6, 9, and 12 weeks, respectively. The decline in PP levels 3 weeks after transplantation was associated with beta-cell development in the graft. PP was also secreted by fetal pig pancreatic explants transplanted into diabetic NOD/SCID mice, with plasma levels measurable in the first week after the tissue was grafted. In immunocompetent BALB/c mice transplanted with the tissue, PP was detectable in plasma for 2 days after transplantation but not at 4 days, when cellular rejection commenced, or thereafter. We conclude that plasma PP levels can be used as a marker of the viability of fetal porcine pancreatic tissue in the first 3 weeks after

  20. A fluorescence-based method for direct measurement of submicrosecond intramolecular contact formation in biopolymers: an exploratory study with polypeptides.

    Science.gov (United States)

    Hudgins, Robert R; Huang, Fang; Gramlich, Gabriela; Nau, Werner M

    2002-01-30

    A fluorescent amino acid derivative (Fmoc-DBO) has been synthesized, which contains 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) as a small, hydrophilic fluorophore with an extremely long fluorescence lifetime (325 ns in H2O and 505 ns in D2O under air). Polypeptides containing both the DBO residue and an efficient fluorescence quencher allow the measurement of rate constants for intramolecular end-to-end contact formation. Bimolecular quenching experiments indicated that Trp, Cys, Met, and Tyr are efficient quenchers of DBO (k(q) = 20, 5.1, 4.5, and 3.6 x 10(8) M(-1) x s(-1) in D2O), while the other amino acids are inefficient. The quenching by Trp, which was selected as an intrinsic quencher, is presumed to involve exciplex-induced deactivation. Flexible, structureless polypeptides, Trp-(Gly-Ser)n-DBO-NH2, were prepared by standard solid-phase synthesis, and the rates of contact formation were measured through the intramolecular fluorescence quenching of DBO by Trp with time-correlated single-photon counting, laser flash photolysis, and steady-state fluorometry. Rate constants of 4.1, 6.8, 4.9, 3.1, 2.0, and 1.1 x 10(7) s(-1) for n = 0, 1, 2, 4, 6, and 10 were obtained. Noteworthy was the relatively slow quenching for the shortest peptide (n = 0). The kinetic data are in agreement with recent transient absorption studies of triplet probes for related peptides, but the rate constants are significantly larger. In contrast to the flexible structureless Gly-Ser polypeptides, the polyproline Trp-Pro4-DBO-NH2 showed insignificant fluorescence quenching, suggesting that a high polypeptide flexibility and the possibility of probe-quencher contact is essential to induce quenching. Advantages of the new fluorescence-based method for measuring contact formation rates in biopolymers include high accuracy, fast time range (100 ps-1 micros), and the possibility to perform measurements in water under air.

  1. Vasoactive intestinal polypeptide induces glycogenolysis in mouse cortical slices: a possible regulatory mechanism for the local control of energy metabolism.

    OpenAIRE

    Magistretti, P J; Morrison, J H; Shoemaker, W J; Sapin, V; Bloom, F E

    1981-01-01

    Mouse cerebral cortex slices will synthesize [3H]glycogen in vitro. Vasoactive intestinal polypeptide (VIP) stimulates the enzymatic breakdown of this [3H]glycogen. The concentration giving 50% of maximum effectiveness (EC50) is 26 nM. Under the same experimental conditions norepinephrine also induces a concentration-dependent [3H]glycogen hydrolysis with an EC50 of 500 nM. The effect of VIP is not mediated by the release of norepinephrine because it is not blocked by the noradrenergic antago...

  2. Discovery of a mammalian splice variant of myostatin that stimulates myogenesis.

    Directory of Open Access Journals (Sweden)

    Ferenc Jeanplong

    Full Text Available Myostatin plays a fundamental role in regulating the size of skeletal muscles. To date, only a single myostatin gene and no splice variants have been identified in mammals. Here we describe the splicing of a cryptic intron that removes the coding sequence for the receptor binding moiety of sheep myostatin. The deduced polypeptide sequence of the myostatin splice variant (MSV contains a 256 amino acid N-terminal domain, which is common to myostatin, and a unique C-terminus of 65 amino acids. Western immunoblotting demonstrated that MSV mRNA is translated into protein, which is present in skeletal muscles. To determine the biological role of MSV, we developed an MSV over-expressing C2C12 myoblast line and showed that it proliferated faster than that of the control line in association with an increased abundance of the CDK2/Cyclin E complex in the nucleus. Recombinant protein made for the novel C-terminus of MSV also stimulated myoblast proliferation and bound to myostatin with high affinity as determined by surface plasmon resonance assay. Therefore, we postulated that MSV functions as a binding protein and antagonist of myostatin. Consistent with our postulate, myostatin protein was co-immunoprecipitated from skeletal muscle extracts with an MSV-specific antibody. MSV over-expression in C2C12 myoblasts blocked myostatin-induced Smad2/3-dependent signaling, thereby confirming that MSV antagonizes the canonical myostatin pathway. Furthermore, MSV over-expression increased the abundance of MyoD, Myogenin and MRF4 proteins (P<0.05, which indicates that MSV stimulates myogenesis through the induction of myogenic regulatory factors. To help elucidate a possible role in vivo, we observed that MSV protein was more abundant during early post-natal muscle development, while myostatin remained unchanged, which suggests that MSV may promote the growth of skeletal muscles. We conclude that MSV represents a unique example of intra-genic regulation in which a

  3. Influenza A (H3N2) Variant Virus

    Science.gov (United States)

    ... Swine Variant Pandemic Other Influenza A (H3N2) Variant Virus Language: English (US) Español Recommend on Facebook Tweet Share Compartir Influenza viruses that normally circulate in pigs are called “variant” ...

  4. Treatment of spelling variants in Setswana monolingual dictionaries

    African Journals Online (AJOL)

    user

    . ..... Table 8: Variants of Names of persons and places. Setswana variants. English. Aforika, Aferika. Africa. Baebele, Babele, Beibele. Bible. Ennyelane, Engelane ..... MWEs. As in variation amongst individual words, the MWEs such as idioms.

  5. Combined analyses of 20 common obesity susceptibility variants

    DEFF Research Database (Denmark)

    Sandholt, Camilla Helene; Sparsø, Thomas; Grarup, Niels

    2010-01-01

    Genome-wide association studies and linkage studies have identified 20 validated genetic variants associated with obesity and/or related phenotypes. The variants are common, and they individually exhibit small-to-modest effect sizes.......Genome-wide association studies and linkage studies have identified 20 validated genetic variants associated with obesity and/or related phenotypes. The variants are common, and they individually exhibit small-to-modest effect sizes....

  6. De novo DESIGN AND SYNTHESIS OF AN ICE-BINDING, DENDRIMERIC, POLYPEPTIDE BASED ON INSECT ANTIFREEZE PROTEINS

    Directory of Open Access Journals (Sweden)

    Ricardo Vera Bravo

    2011-12-01

    Full Text Available A new strategy is presented for the designand synthesis of peptides that exhibitice-binding and antifreeze activity. Apennant-type dendrimer polypeptidescaffold combining an α-helical backbonewith four short β-strand branches wassynthesized in solid phase using Fmocchemistry in a divergent approach. The51-residue dendrimer was characterizedby reverse phase high performance liquidchromatography, mass spectrometry andcircular dichroism. Each β-strand branchcontained three overlapping TXT aminoacid repeats, an ice-binding motif foundin the ice-binding face of the sprucebudworm (Choristoneura fumiferanaand beetle (Tenebrio molitor antifreezeproteins. Ice crystals in the presence ofthe polypeptide monomer displayed flat,hexagonal plate morphology, similar tothat produced by weakly active antifreezeproteins. An oxidized dimeric form of thedendrimer polypeptide also produced flathexagonal ice crystals and was capableof inhibiting ice crystal growth upontemperature reduction, a phenomenontermed thermal hysteresis, a definingproperty of antifreeze proteins. Linkageof the pennant-type dendrimer to a trifunctionalcascade-type polypeptideproduced a trimeric macromolecule thatgave flat hexagonal ice crystals withhigher thermal hysteresis activity thanthe dimer or monomer and an ice crystal burst pattern similar to that producedby samples containing insect antifreezeproteins. This macromolecule was alsocapable of inhibiting ice recrystallization.

  7. Plasma low-molecular-weight proteome profiling identified neuropeptide-Y as a prostate cancer biomarker polypeptide.

    Science.gov (United States)

    Ueda, Koji; Tatsuguchi, Ayako; Saichi, Naomi; Toyama, Atsuhiko; Tamura, Kenji; Furihata, Mutsuo; Takata, Ryo; Akamatsu, Shusuke; Igarashi, Masahiro; Nakayama, Masato; Sato, Taka-Aki; Ogawa, Osamu; Fujioka, Tomoaki; Shuin, Taro; Nakamura, Yusuke; Nakagawa, Hidewaki

    2013-10-04

    In prostate cancer diagnosis, PSA test has greatly contributed to the early detection of prostate cancer; however, expanding overdiagnosis and unnecessary biopsies have emerged as serious issues. To explore plasma biomarkers complementing the specificity of PSA test, we developed a unique proteomic technology QUEST-MS (Quick Enrichment of Small Targets for Mass Spectrometry). The QUEST-MS method based on 96-well formatted sequential reversed-phase chromatography allowing efficient enrichment of <20 kDa proteins quickly and reproducibly. Plasma from 24 healthy controls, 19 benign prostate hypertrophy patients, and 73 prostate cancer patients were purified with QUEST-MS and analyzed by LC/MS/MS. Among 153 057 nonredundant peptides, 189 peptides showed prostate cancer specific detection pattern, which included a neurotransmitter polypeptide neuropeptide-Y (NPY). We further validated the screening results by targeted multiple reaction monitoring technology using independent sample set (n = 110). The ROC curve analysis revealed that logistic regression-based combination of NPY, and PSA showed 81.5% sensitivity and 82.2% specificity for prostate cancer diagnosis. Thus QUEST-MS technology allowed comprehensive and high-throughput profiling of plasma polypeptides and had potential to effectively uncover very low abundant tumor-derived small molecules, such as neurotransmitters, peptide hormones, or cytokines.

  8. Liver fatty acid binding protein is the mitosis-associated polypeptide target of a carcinogen in rat hepatocytes

    International Nuclear Information System (INIS)

    Bassuk, J.A.; Tsichlis, P.N.; Sorof, S.

    1987-01-01

    Hepatocytes in normal rat liver were found previously to contain a cytoplasmic 14,000-dalton polypeptide (p14) that is associated with mitosis and is the principal early covalent target of activated metabolites of the carcinogen N-2-fluorenylacetamide (2-acetylaminofluorene). The level of immunohistochemically detected p14 was low when growth activity of hepatocytes was low, was markedly elevated during mitosis in normal and regenerating livers, but was very high throughout interphase during proliferation of hyperplastic and malignant hepatocytes induced in rat liver by a carcinogen (N-2-fluorenylacetamide or 3'-methyl-4-dimethylaminoazobenzene). The authors report here that p14 is the liver fatty acid binding protein. The nucleotide sequence of p14 cDNA clones, isolated by screening a rat liver cDNA library in bacteriophage λgt11 using p14 antiserum, was completely identical to part of the sequence reported for liver fatty acid binding protein. Furthermore, the two proteins shared the following properties: size of mRNA, amino acid composition, molecular size according to NaDodSO 4 gel electrophoresis, and electrophoretic mobilities in a Triton X-100/acetic acid/urea gel. The two polypeptides bound oleic acid similarly. Finally, identical elevations of cytoplasmic immunostain were detected specifically in mitotic hepatocytes with either antiserum. The collected findings are suggestive that liver fatty acid binding protein may carry ligands that promote hepatocyte division and may transport certain activated chemical carcinogens

  9. Expression and purification of short hydrophobic elastin-like polypeptides with maltose-binding protein as a solubility tag.

    Science.gov (United States)

    Bataille, Laure; Dieryck, Wilfrid; Hocquellet, Agnès; Cabanne, Charlotte; Bathany, Katell; Lecommandoux, Sébastien; Garbay, Bertrand; Garanger, Elisabeth

    2015-06-01

    Elastin-like polypeptides (ELPs) are biodegradable polymers with interesting physico-chemical properties for biomedical and biotechnological applications. The recombinant expression of hydrophobic elastin-like polypeptides is often difficult because they possess low transition temperatures, and therefore form aggregates at sub-ambient temperatures. To circumvent this difficulty, we expressed in Escherichia coli three hydrophobic ELPs (VPGIG)n with variable lengths (n=20, 40, and 60) in fusion with the maltose-binding protein (MBP). Fusion proteins were soluble and yields of purified MBP-ELP ranged between 66 and 127mg/L culture. After digestion of the fusion proteins by enterokinase, the ELP moiety was purified by using inverse transition cycling. The purified fraction containing ELP40 was slightly contaminated by traces of undigested fusion protein. Purification of ELP60 was impaired because of co-purification of the MBP tag during inverse transition cycling. ELP20 was successfully purified to homogeneity, as assessed by gel electrophoresis and mass spectrometry analyses. The transition temperature of ELP20 was measured at 15.4°C in low salt buffer. In conclusion, this method can be used to produce hydrophobic ELP of low molecular mass. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Protective effect of topically applied polypeptide from Chlamys farreri against ultraviolet radiation-induced chronic skin damage in guinea pig

    Science.gov (United States)

    Chi, Mingliang; Cao, Pengli; Yu, Guoying; Zhu, Li; Wang, Yuejun; Wang, Chunbo

    2003-12-01

    Polypeptide from Chlamys farreri (PCF), a topical polypeptide isolated from Chlamys farreri, was used in this experiment aimed to investigate the photoprotective effect of PCF against chronic skin damage induced by ultraviolet A (UVA) and ultraviolet B (UVB) radiation. The chronic ultraviolet-irradiated guinea pig model was established, and visible changes in the skin including wrinkling, sagging and erythema were observed. Malondialdehyde (MDA) and antioxidant enzymes including superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) in the dorsal skin were determined using biochemical methods. The results showed: (1) PCF (5 % and 20%) could greatly protect the dorsal skin of guinea pig against wrinkling, sagging and erythema induced by UV radiation in a concentration-dependent manner. (2) PCF could reduce MDA formation in the dorsal skin caused by UV irradiation, while increasing the activities of SOD and GSH-px. (3) The differences among the PCF groups and UV model group were significant ( Psolar UV spectrum photoprotection; and that the antioxidant property of PCF might play a role in photoprotection.

  11. Dual binding mode of the nascent polypeptide-associated complex reveals a novel universal adapter site on the ribosome.

    Science.gov (United States)

    Pech, Markus; Spreter, Thomas; Beckmann, Roland; Beatrix, Birgitta

    2010-06-18

    Nascent polypeptide-associated complex (NAC) was identified in eukaryotes as the first cytosolic factor that contacts the nascent polypeptide chain emerging from the ribosome. NAC is present as a homodimer in archaea and as a highly conserved heterodimer in eukaryotes. Mutations in NAC cause severe embryonically lethal phenotypes in mice, Drosophila melanogaster, and Caenorhabditis elegans. In the yeast Saccharomyces cerevisiae NAC is quantitatively associated with ribosomes. Here we show that NAC contacts several ribosomal proteins. The N terminus of betaNAC, however, specifically contacts near the tunnel exit ribosomal protein Rpl31, which is unique to eukaryotes and archaea. Moreover, the first 23 amino acids of betaNAC are sufficient to direct an otherwise non-associated protein to the ribosome. In contrast, alphaNAC (Egd2p) contacts Rpl17, the direct neighbor of Rpl31 at the ribosomal tunnel exit site. Rpl31 was also recently identified as a contact site for the SRP receptor and the ribosome-associated complex. Furthermore, in Escherichia coli peptide deformylase (PDF) interacts with the corresponding surface area on the eubacterial ribosome. In addition to the previously identified universal adapter site represented by Rpl25/Rpl35, we therefore refer to Rpl31/Rpl17 as a novel universal docking site for ribosome-associated factors on the eukaryotic ribosome.

  12. Skin peptide tyrosine-tyrosine, a member of the pancreatic polypeptide family: isolation, structure, synthesis, and endocrine activity.

    Science.gov (United States)

    Mor, A; Chartrel, N; Vaudry, H; Nicolas, P

    1994-10-25

    Pancreatic polypeptide, peptide tyrosine-tyrosine (PYY), and neuropeptide tyrosine (NPY), three members of a family of structurally related peptides, are mainly expressed in the endocrine pancreas, in endocrine cells of the gut, and in the brain, respectively. In the present study, we have isolated a peptide of the pancreatic polypeptide family from the skin of the South American arboreal frog Phyllomedusa bicolor. The primary structure of the peptide was established as Tyr-Pro-Pro-Lys-Pro-Glu-Ser-Pro-Gly-Glu10-Asp-Ala-Ser-Pro-Glu-Glu- Met-Asn- Lys-Tyr20-Leu-Thr-Ala-Leu-Arg-His-Tyr-Ile-Asn-Leu30-Val-Thr- Arg-Gln-Arg-Tyr-NH2 . This unusual peptide, named skin peptide tyrosine-tyrosine (SPYY), exhibits 94% similarity with PYY from the frog Rana ridibunda. A synthetic replicate of SPYY inhibits melanotropin release from perifused frog neurointermediate lobes in very much the same way as NPY. These results demonstrate the occurrence of a PYY-like peptide in frog skin. Our data also suggest the existence of a pituitary-skin regulatory loop in amphibians.

  13. Structural stability of Amandin, a major allergen from almond (Prunus dulcis), and its acidic and basic polypeptides.

    Science.gov (United States)

    Albillos, Silvia M; Menhart, Nicholas; Fu, Tong-Jen

    2009-06-10

    Information relating to the resistance of food allergens to thermal and/or chemical denaturation is critical if a reduction in protein allergenicity is to be achieved through food-processing means. This study examined the changes in the secondary structure of an almond allergen, amandin, and its acidic and basic polypeptides as a result of thermal and chemical denaturation. Amandin ( approximately 370 kDa) was purified by cryoprecipitation followed by gel filtration chromatography and subjected to thermal (13-96 degrees C) and chemical (urea and dithiothreitol) treatments. Changes in the secondary structure of the protein were followed using circular dichroism spectroscopy. The secondary structure of the hexameric amandin did not undergo remarkable changes at temperatures up to 90 degrees C, although protein aggregation was observed. In the presence of a reducing agent, irreversible denaturation occurred with the following experimental values: T(m) = 72.53 degrees C (transition temperature), DeltaH = 87.40 kcal/mol (unfolding enthalpy), and C(p) = 2.48 kcal/(mol degrees C) (heat capacity). The concentration of urea needed to achieve 50% denaturation was 2.59 M, and the Gibbs free energy of chemical denaturation was calculated to be DeltaG = 3.82 kcal/mol. The basic and acidic polypeptides of amandin had lower thermal stabilities than the multimeric protein.

  14. Micelles Formed by Polypeptide Containing Polymers Synthesized Via N-Carboxy Anhydrides and Their Application for Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Dimitrios Skoulas

    2017-06-01

    Full Text Available The development of multifunctional polymeric materials for biological applications is mainly guided by the goal of achieving the encapsulation of pharmaceutical compounds through a self-assembly process to form nanoconstructs that control the biodistribution of the active compounds, and therefore minimize systemic side effects. Micelles are formed from amphiphilic polymers in a selective solvent. In biological applications, micelles are formed in water, and their cores are loaded with hydrophobic pharmaceutics, where they are solubilized and are usually delivered through the blood compartment. Even though a large number of polymeric materials that form nanocarrier delivery systems has been investigated, a surprisingly small subset of these technologies has demonstrated potentially curative preclinical results, and fewer have progressed towards commercialization. One of the most promising classes of polymeric materials for drug delivery applications is polypeptides, which combine the properties of the conventional polymers with the 3D structure of natural proteins, i.e., α-helices and β-sheets. In this article, the synthetic pathways followed to develop well-defined polymeric micelles based on polypeptides prepared through ring-opening polymerization (ROP of N-carboxy anhydrides are reviewed. Among these works, we focus on studies performed on micellar delivery systems to treat cancer. The review is limited to systems presented from 2000–2017.

  15. Development of industrial variant specification systems

    DEFF Research Database (Denmark)

    Hansen, Benjamin Loer

    be developed from a holistic and strategically anchored point of view. Another assumption is that this is a challenge for many industrial companies. Even though the literature presents many considerations on general issues covering new information technology, little work is found on the business perspectives...... are discussed. A list of structural variables and solution components has been created. These are related to four design aspects in the holistic system design covering the aspects of process design, selection of resources (such as hardware, software and humans), the design of information structures...... solution elements and structural variables to be used in the design of variant specification systems. The thesis presents a “top-down” procedure to be used to develop variant specification systems from a strategically anchored and holistic point of view. A methodology and related task variables...

  16. The Saccharomyces Genome Database Variant Viewer.

    Science.gov (United States)

    Sheppard, Travis K; Hitz, Benjamin C; Engel, Stacia R; Song, Giltae; Balakrishnan, Rama; Binkley, Gail; Costanzo, Maria C; Dalusag, Kyla S; Demeter, Janos; Hellerstedt, Sage T; Karra, Kalpana; Nash, Robert S; Paskov, Kelley M; Skrzypek, Marek S; Weng, Shuai; Wong, Edith D; Cherry, J Michael

    2016-01-04

    The Saccharomyces Genome Database (SGD; http://www.yeastgenome.org) is the authoritative community resource for the Saccharomyces cerevisiae reference genome sequence and its annotation. In recent years, we have moved toward increased representation of sequence variation and allelic differences within S. cerevisiae. The publication of numerous additional genomes has motivated the creation of new tools for their annotation and analysis. Here we present the Variant Viewer: a dynamic open-source web application for the visualization of genomic and proteomic differences. Multiple sequence alignments have been constructed across high quality genome sequences from 11 different S. cerevisiae strains and stored in the SGD. The alignments and summaries are encoded in JSON and used to create a two-tiered dynamic view of the budding yeast pan-genome, available at http://www.yeastgenome.org/variant-viewer. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  17. Angiography of histopathologic variants of synovial sarcoma

    International Nuclear Information System (INIS)

    Lois, J.F.; Fischer, H.J.; Mirra, J.M.; Gomes, A.S.; California Univ., Los Angeles

    1986-01-01

    Synovial sarcomas are rare soft tissue tumors which histopathologically can be divided into monophasic, biphasic and mixed variants. As part of a protocol for intra-arterial chemotherapy 12 patients with biopsy proven synovial sarcoma underwent angiography. The angiograms on these patients were reviewed to determine whether synovial sarcomas and their variants demonstrated a characteristic angiographic appearance. Synovial sarcomas appeared angiographically as soft tissue masses which showed a fine network of tumor vessels with an inhomogeneous capillary blush. Their degree of vascularity varied according to their histopathology. Monophasic synovial sarcomas demonstrated in general a higher degree of neovascularity than the biphasic form. This finding was also suggested by histopathologic analysis of the vessels in the tumor. Although angiography did not show a distinctive vascular pattern it may be useful to evaluate tumor size and vascularity. (orig.)

  18. Membrane polypeptide in rabbit erythrocytes associated with the inhibition of L-lactate transport by a synthetic anhydride of lactic acid

    International Nuclear Information System (INIS)

    Donovan, J.A.; Jennings, M.L.

    1985-01-01

    The synthetic lactyl anhydride isobutylcarbonyl lactyl anhydride (iBCLA), a selective and potent inhibitor of L-(+)-lactate transport in rabbit erythrocytes, reduces the chemical labeling of a 40-50-kdalton polypeptide by tritiated 4,4'-diisothiocyanato-2,2'-dihydrostilbenedisulfonate ([ 3 H]H 2 DIDS). iBCLA does so in a dose-dependent manner at concentrations that strongly inhibit lactate-lactate exchange but not chloride-phosphate exchange. These labeling experiments and inhibition reversal studies using iBCLA, p-(chloro-mercuri)benzenesulfonic acid (pCMBS), and dithiothreitol (DDT) suggest that iBCLA does not act at sulfhydryl groups but at or near an amino group that is near a disulfide linkage in the polypeptide which catalyzes lactate transport. These experiments support the association between specific monocarboxylate transport and a 40-50-kdalton membrane-bound polypeptide of the rabbit erythrocyte

  19. Two-dimensional electrophoretic analysis of transformation-sensitive polypeptides during chemically, spontaneously, and oncogene-induced transformation of rat liver epithelial cells

    DEFF Research Database (Denmark)

    Wirth, P J; Luo, L D; Fujimoto, Y

    1992-01-01

    ; AFB), spontaneously, and oncogene (v-Ha-ras, v-raf, and v-myc/v-raf)-induced transformation of RLE cells. Two-dimensional mapping of [35S]methionine-labeled whole cell lysate, cell-free in vitro translation products and [32P]orthophosphate-labeled polypeptides revealed subsets of polypeptides specific...... for each transformation modality. A search of the RLE protein database indicated the specific subcellular location for the majority of these transformation-sensitive proteins. Significant alterations in the expression of the extracellular matrix protein, fibronectin, as well as tropomyosin......- and intermediate filament-related polypeptides (vimentin, beta-tubulin, the cytokeratins, and actin) were observed among the various transformant cell lines. Immunoprecipitation and Western immunoblot analysis of tropomyosin expression in four individual AFB-, as well as four spontaneously induced, and each...

  20. N-(2-hydroxy) propyl-3-trimethylammonium chitosan chloride: An immune-enhancing adjuvant for hepatitis E virus recombinant polypeptide vaccine in mice.

    Science.gov (United States)

    Tao, Wei; Zheng, Hai-Qun; Fu, Ting; He, Zhuo-Jing; Hong, Yan

    2017-08-03

    Adjuvants are essential for enhancing vaccine potency by improving the humoral and/or cell-mediated immune response to vaccine antigens. This study was performed to evaluate the immuno-enhancing characteristic of N-(2-hydroxy) propyl-3-trimethylammonium chitosan chloride (HTCC), the cationically modified chitosan, as an adjuvant for hepatitis E virus (HEV) recombinant polypeptide vaccine. Animal experiments showed that HTCC provides adjuvant activity when co-administered with HEV recombinant polypeptide vaccine by intramuscularly route. Vaccination using HTCC as an adjuvant was associated with increases of the serum HEV-specific IgG antibodies, splenocytes proliferation and the growths of CD4 + CD8 - T lymphocytes and IFN-γ-secreting T lymphocytes in peripheral blood. These findings suggested that HTCC had strong immuno-enhancing effect. Our findings are the first to demonstrate that HTCC is safe and effective in inducing a good antibody response and stimulating Th1-biased immune responses for HEV recombinant polypeptide vaccine.

  1. Accumulation of New Polypeptides in Ri T-DNA-Transformed Roots of Tomato (Lycopersicon esculentum) during the Development of Vesicular-Arbuscular Mycorrhizae.

    Science.gov (United States)

    Simoneau, P; Louisy-Louis, N; Plenchette, C; Strullu, D G

    1994-06-01

    Root-inducing transferred-DNA (Ri T-DNA)-transformed roots of tomato (Lycopersicon esculentum) were in vitro inoculated with surface-sterilized vesicular-arbuscular mycorrhizal leek root pieces. About 1 week after inoculation, the infection of the transformed root culture by the fungal endophyte was confirmed by photonic microscopy. Total proteins were extracted from the mycorrhizal roots and analyzed by two-dimensional polyacrylamide gel electrophoresis. Control gels were run with proteins extracted from noninoculated roots mixed with purified intraradical vesicles and extraradical hyphae. Comparison of the resulting patterns revealed the presence of two polypeptides with estimated apparent masses of 24 and 39 kDa that were detected only in infected roots. Polypeptides with similar migration parameters were not detected in roots challenged with spore extracts, suggesting that the accumulation of the polypeptides was directly linked to root colonization by the fungus rather than to induction by fungus-derived elicitors.

  2. Fine-Mapping of Common Genetic Variants Associated with Colorectal Tumor Risk Identified Potential Functional Variants.

    Directory of Open Access Journals (Sweden)

    Mengmeng Du

    Full Text Available Genome-wide association studies (GWAS have identified many common single nucleotide polymorphisms (SNPs associated with colorectal cancer risk. These SNPs may tag correlated variants with biological importance. Fine-mapping around GWAS loci can facilitate detection of functional candidates and additional independent risk variants. We analyzed 11,900 cases and 14,311 controls in the Genetics and Epidemiology of Colorectal Cancer Consortium and the Colon Cancer Family Registry. To fine-map genomic regions containing all known common risk variants, we imputed high-density genetic data from the 1000 Genomes Project. We tested single-variant associations with colorectal tumor risk for all variants spanning genomic regions 250-kb upstream or downstream of 31 GWAS-identified SNPs (index SNPs. We queried the University of California, Santa Cruz Genome Browser to examine evidence for biological function. Index SNPs did not show the strongest association signals with colorectal tumor risk in their respective genomic regions. Bioinformatics analysis of SNPs showing smaller P-values in each region revealed 21 functional candidates in 12 loci (5q31.1, 8q24, 11q13.4, 11q23, 12p13.32, 12q24.21, 14q22.2, 15q13, 18q21, 19q13.1, 20p12.3, and 20q13.33. We did not observe evidence of additional independent association signals in GWAS-identified regions. Our results support the utility of integrating data from comprehensive fine-mapping with expanding publicly available genomic databases to help clarify GWAS associations and identify functional candidates that warrant more onerous laboratory follow-up. Such efforts may aid the eventual discovery of disease-causing variant(s.

  3. Unusual variant of Cantrell′s pentalogy?

    Directory of Open Access Journals (Sweden)

    Kumar Basant

    2008-01-01

    Full Text Available A 12-hour-old male infant presented with prolapsed abdominal content through a defect on left side of chest wall with respiratory distress. A thorough clinical examination suggested absence of ectopia cordis, abdominal wall defect, and any bony anomaly. The child expired after 6 hours of admission because of respiratory distress and electrolyte imbalance. Is congenital defect of chest wall associated with diaphragmatic hernia without ectopia cordis and omphalocele, an unusual variant of Cantrell′s pentalogy?

  4. Random Plant Viral Variants Attain Temporal Advantages During Systemic Infections and in Turn Resist other Variants of the Same Virus.

    Science.gov (United States)

    Zhang, Xiao-Feng; Guo, Jiangbo; Zhang, Xiuchun; Meulia, Tea; Paul, Pierce; Madden, Laurence V; Li, Dawei; Qu, Feng

    2015-10-20

    Infection of plants with viruses containing multiple variants frequently leads to dominance by a few random variants in the systemically infected leaves (SLs), for which a plausible explanation is lacking. We show here that SL dominance by a given viral variant is adequately explained by its fortuitous lead in systemic spread, coupled with its resistance to superinfection by other variants. We analyzed the fate of a multi-variant turnip crinkle virus (TCV) population in Arabidopsis and N. benthamiana plants. Both wild-type and RNA silencing-defective plants displayed a similar pattern of random dominance by a few variant genotypes, thus discounting a prominent role for RNA silencing. When introduced to plants sequentially as two subpopulations, a twelve-hour head-start was sufficient for the first set to dominate. Finally, SLs of TCV-infected plants became highly resistant to secondary invasions of another TCV variant. We propose that random distribution of variant foci on inoculated leaves allows different variants to lead systemic movement in different plants. The leading variants then colonize large areas of SLs, and resist the superinfection of lagging variants in the same areas. In conclusion, superinfection resistance is the primary driver of random enrichment of viral variants in systemically infected plants.

  5. Spatially variant periodic structures in electromagnetics

    Science.gov (United States)

    Rumpf, Raymond C.; Pazos, Javier J.; Digaum, Jennefir L.; Kuebler, Stephen M.

    2015-01-01

    Spatial transforms are a popular technique for designing periodic structures that are macroscopically inhomogeneous. The structures are often required to be anisotropic, provide a magnetic response, and to have extreme values for the constitutive parameters in Maxwell's equations. Metamaterials and photonic crystals are capable of providing these, although sometimes only approximately. The problem still remains about how to generate the geometry of the final lattice when it is functionally graded, or spatially varied. This paper describes a simple numerical technique to spatially vary any periodic structure while minimizing deformations to the unit cells that would weaken or destroy the electromagnetic properties. New developments in this algorithm are disclosed that increase efficiency, improve the quality of the lattices and provide the ability to design aplanatic metasurfaces. The ability to spatially vary a lattice in this manner enables new design paradigms that are not possible using spatial transforms, three of which are discussed here. First, spatially variant self-collimating photonic crystals are shown to flow unguided waves around very tight bends using ordinary materials with low refractive index. Second, multi-mode waveguides in spatially variant band gap materials are shown to guide waves around bends without mixing power between the modes. Third, spatially variant anisotropic materials are shown to sculpt the near-field around electric components. This can be used to improve electromagnetic compatibility between components in close proximity. PMID:26217058

  6. Warty Carcinoma Penis: An Uncommon Variant

    Directory of Open Access Journals (Sweden)

    Sushma Thapa

    2017-01-01

    Full Text Available Penile carcinoma frequency varies widely in different parts of the world and comprises 1–10% of all the malignancies in males. Majority of the cases of penile carcinoma are squamous cell carcinoma of penis comprising 60% to 70% of all cases. Warty carcinoma of penis is an unusual neoplasm and a variant of penile squamous cell carcinoma comprising 5%–10% of all the variants. The other histological variants include basaloid, verrucous, papillary, sarcomatous, mixed, and adenosquamous carcinoma. The various histological entities with an exophytic papillary lesions including warty carcinoma are together referred to as the “verruciform” group of neoplasms. The warty carcinoma has to be differentiated from these lesions and is typically distinguished by histological features of hyperkeratosis, arborescent papillomatosis, acanthosis, and prominent koilocytosis with nuclear pleomorphism. We present a case of 65-year-old male with growth measuring 6×4 cm in the penis who underwent total penectomy and was diagnosed as warty carcinoma penis.

  7. Cryptanalysis of RSA and its variants

    CERN Document Server

    Hinek, M Jason

    2009-01-01

    Thirty years after RSA was first publicized, it remains an active research area. Although several good surveys exist, they are either slightly outdated or only focus on one type of attack. Offering an updated look at this field, Cryptanalysis of RSA and Its Variants presents the best known mathematical attacks on RSA and its main variants, including CRT-RSA, multi-prime RSA, and multi-power RSA. Divided into three parts, the book first introduces RSA and reviews the mathematical background needed for the majority of attacks described in the remainder of the text. It then brings together all of the most popular mathematical attacks on RSA and its variants. For each attack presented, the author includes a mathematical proof if possible or a mathematical justification for attacks that rely on assumptions. For the attacks that cannot be proven, he gives experimental evidence to illustrate their practical effectiveness. Focusing on mathematical attacks that exploit the structure of RSA and specific parameter choic...

  8. MR imaging of the ankle: Normal variants

    International Nuclear Information System (INIS)

    Noto, A.M.; Cheung, Y.; Rosenberg, Z.S.; Norman, A.; Leeds, N.E.

    1987-01-01

    Thirty asymptomatic ankles were studied with high-resolution surface coil MR imaging. The thirty ankles were reviewed for identification or normal structures. The MR appearance of the deltoid and posterior to talo-fibular ligaments, peroneous brevis and longus tendons, and posterior aspect of the tibial-talar joint demonstrated several normal variants not previously described. These should not be misinterpreted as pathologic processes. The specific findings included (1) cortical irregularity of the posterior tibial-talar joint in 27 of 30 cases which should not be mistaken for osteonecrois; (2) normal posterior talo-fibular ligament with irregular and frayed inhomogeneity, which represents a normal variant in seven of ten cases; and (3) fluid in the shared peroneal tendons sheath which may be confused for a longitudinal tendon tear in three of 30 cases. Ankle imaging with the use of MR is still a relatively new procedure. Further investigation is needed to better define normal anatomy as well as normal variants. The authors described several structures that normally present with variable MR imaging appearances. This is clinically significant in order to maintain a high sensitivity and specificity in MR imaging interpretation

  9. Characterization of mutants expressing thermostable D1 and D2 polypeptides of photosystem II in the cyanobacterium Synechococcus elongatus PCC 7942.

    Science.gov (United States)

    Haraguchi, Norihisa; Kaseda, Jun; Nakayama, Yasumune; Nagahama, Kazuhiro; Ogawa, Takahira; Matsuoka, Masayoshi

    2018-06-08

    Photosystem II complex embedded in thylakoid membrane performs oxygenic photosynthesis where the reaction center D1/D2 heterodimer accommodates all components of the electron transport chain. To express thermostable D1/D2 heterodimer in a cyanobacterium Synechococcus elongatus PCC 7942, we constructed a series of mutant strains whose psbA1 and psbD1 genes encoding, respectively, the most highly expressed D1 and D2 polypeptides were replaced with those of a thermophilic strain, Thermosynechococcus vulcanus. Because the C-terminal 16 amino acid sequences of D1 polypeptides should be processed prior to maturation but diverge from each other, we also constructed the psbA1ΔC-replaced strain expressing a thermostable D1 polypeptide devoid of the C-terminal extension. The psbA1/psbD1-replaced strain showed decreased growth rate and oxygen evolution rate, suggesting inefficient photosystem II. Immunoblot analyses for thermostable D1, D2 polypeptides revealed that the heterologous D1 protein was absent in thylakoid membrane from any mutant strains with psbA1, psbA1ΔC, and psbA1/psbD1-replacements, whereas the heterologous D2 protein was present in thylakoid membrane as well as purified photosystem II complex from the psbA1/psbD1-replaced strain. In the latter strain, the compensatory expression of psbA3 and psbD2 genes was elevated. These data suggest that heterologous D2 polypeptide could be combined with the host D1 polypeptide to form chimeric D1/D2 heterodimer, whereas heterologous D1 polypeptide even without the C-terminal extension was unable to make complex with the host D2 polypeptide. Since the heterologous D1 could not be detected even in the whole cells of psbA1/psbD1-replaced strain, the rapid degradation of unprocessed or unassembled heterologous D1 was implicated. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  10. Binding Properties of Streptococcus gordonii SspA and SspB (Antigen I/II Family) Polypeptides Expressed on the Cell Surface of Lactococcus lactis MG1363

    OpenAIRE

    Holmes, Ann R.; Gilbert, Christophe; Wells, Jeremy M.; Jenkinson, Howard F.

    1998-01-01

    The oral bacterium Streptococcus gordonii expresses two cell wall-associated polypeptides, designated SspA (1,542 amino acid residues) and SspB (1,462 amino acid residues), that have 70% sequence identity. These polypeptides are members of the antigen I/II family of oral streptococcal adhesins and mediate the binding of streptococci to salivary glycoproteins, collagen, and other oral microorganisms such as Actinomyces naeslundii. To determine if SspA and SspB have differential binding propert...

  11. Annotating pathogenic non-coding variants in genic regions.

    Science.gov (United States)

    Gelfman, Sahar; Wang, Quanli; McSweeney, K Melodi; Ren, Zhong; La Carpia, Francesca; Halvorsen, Matt; Schoch, Kelly; Ratzon, Fanni; Heinzen, Erin L; Boland, Michael J; Petrovski, Slavé; Goldstein, David B

    2017-08-09

    Identifying the underlying causes of disease requires accurate interpretation of genetic variants. Current methods ineffectively capture pathogenic non-coding variants in genic regions, resulting in overlooking synonymous and intronic variants when searching for disease risk. Here we present the Transcript-inferred Pathogenicity (TraP) score, which uses sequence context alterations to reliably identify non-coding variation that causes disease. High TraP scores single out extremely rare variants with lower minor allele frequencies than missense variants. TraP accurately distinguishes known pathogenic and benign variants in synonymous (AUC = 0.88) and intronic (AUC = 0.83) public datasets, dismissing benign variants with exceptionally high specificity. TraP analysis of 843 exomes from epilepsy family trios identifies synonymous variants in known epilepsy genes, thus pinpointing risk factors of disease from non-coding sequence data. TraP outperforms leading methods in identifying non-coding variants that are pathogenic and is therefore a valuable tool for use in gene discovery and the interpretation of personal genomes.While non-coding synonymous and intronic variants are often not under strong selective constraint, they can be pathogenic through affecting splicing or transcription. Here, the authors develop a score that uses sequence context alterations to predict pathogenicity of synonymous and non-coding genetic variants, and provide a web server of pre-computed scores.

  12. Microsatellite Instability Use in Mismatch Repair Gene Sequence Variant Classification

    Directory of Open Access Journals (Sweden)

    Bryony A. Thompson

    2015-03-01

    Full Text Available Inherited mutations in the DNA mismatch repair genes (MMR can cause MMR deficiency and increased susceptibility to colorectal and endometrial cancer. Microsatellite instability (MSI is the defining molecular signature of MMR deficiency. The clinical classification of identified MMR gene sequence variants has a direct impact on the management of patients and their families. For a significant proportion of cases sequence variants of uncertain clinical significance (also known as unclassified variants are identified, constituting a challenge for genetic counselling and clinical management of families. The effect on protein function of these variants is difficult to interpret. The presence or absence of MSI in tumours can aid in determining the pathogenicity of associated unclassified MMR gene variants. However, there are some considerations that need to be taken into account when using MSI for variant interpretation. The use of MSI and other tumour characteristics in MMR gene sequence variant classification will be explored in this review.

  13. Stable Human Hepatoma Cell Lines for Efficient Regulated Expression of Nucleoside/Nucleotide Analog Resistant and Vaccine Escape Hepatitis B Virus Variants and Woolly Monkey Hepatitis B Virus.

    Directory of Open Access Journals (Sweden)

    Xin Cheng

    Full Text Available Hepatitis B virus (HBV causes acute and chronic hepatitis B (CHB. Due to its error-prone replication via reverse transcription, HBV can rapidly evolve variants that escape vaccination and/or become resistant to CHB treatment with nucleoside/nucleotide analogs (NAs. This is particularly problematic for the first generation NAs lamivudine and adefovir. Though now superseded by more potent NAs, both are still widely used. Furthermore, resistance against the older NAs can contribute to cross-resistance against more advanced NAs. For lack of feasible HBV infection systems, the biology of such variants is not well understood. From the recent discovery of Na+-taurocholate cotransporting polypeptide (NTCP as an HBV receptor new in vitro infection systems are emerging, yet access to the required large amounts of virions, in particular variants, remains a limiting factor. Stably HBV producing cell lines address both issues by allowing to study intracellular viral replication and as a permanent source of defined virions. Accordingly, we generated a panel of new tetracycline regulated TetOFF HepG2 hepatoma cell lines which produce six lamivudine and adefovir resistance-associated and two vaccine escape variants of HBV as well as the model virus woolly monkey HBV (WMHBV. The cell line-borne viruses reproduced the expected NA resistance profiles and all were equally sensitive against a non-NA drug. The new cell lines should be valuable to investigate under standardized conditions HBV resistance and cross-resistance. With titers of secreted virions reaching >3 x 10(7 viral genome equivalents per ml they should also facilitate exploitation of the new in vitro infection systems.

  14. Bovine pancreatic polypeptide (bPP) undergoes significant changes in conformation and dynamics upon binding to DPC micelles.

    Science.gov (United States)

    Lerch, Mirjam; Gafner, Verena; Bader, Reto; Christen, Barbara; Folkers, Gerd; Zerbe, Oliver

    2002-10-04

    The pancreatic polypeptide (PP), a 36-residue, C-terminally amidated polypeptide hormone is a member of the neuropeptide Y (NPY) family. Here, we have studied the structure and dynamics of bovine pancreatic polypeptide (bPP) when bound to DPC-micelles as a membrane-mimicking model as well as the dynamics of bPP in solution. The comparison of structure and dynamics of bPP in both states reveals remarkable differences. The overall correlation time of 5.08ns derived from the 15N relaxation data proves unambiguously that bPP in solution exists as a dimer. Therein, intermolecular as well as intramolecular hydrophobic interactions from residues of both the amphiphilic helix and of the back-folded N terminus contribute to the stability of the PP fold. The overall rigidity is well-reflected in positive values for the heteronuclear NOE for residues 4-34. The membrane-bound species displays a partitioning into a more flexible N-terminal region and a well-defined alpha-helical region comprising residues 17-31. The average RMSD value for residues 17-31 is 0.22(+/-0.09)A. The flexibility of the N terminus is compatible with negative values of the heteronuclear NOE observed for the N-terminal residues 4-12 and low values of the generalized order parameter S(2). The membrane-peptide interface was investigated by micelle-integrating spin-labels and H,2H exchange measurements. It is formed by those residues which make contacts between the C-terminal alpha-helix and the polyproline helix. In contrast to pNPY, also residues from the N terminus display spatial proximity to the membrane interface. Furthermore, the orientation of the C terminus, that presumably contains residues involved in receptor binding, is different in the two environments. We speculate that this pre-positioning of residues could be an important requirement for receptor activation. Moreover, we doubt that the PP fold is of functional relevance for binding at the Y(4) receptor.

  15. Genetic Variants Associated with Circulating Parathyroid Hormone.

    Science.gov (United States)

    Robinson-Cohen, Cassianne; Lutsey, Pamela L; Kleber, Marcus E; Nielson, Carrie M; Mitchell, Braxton D; Bis, Joshua C; Eny, Karen M; Portas, Laura; Eriksson, Joel; Lorentzon, Mattias; Koller, Daniel L; Milaneschi, Yuri; Teumer, Alexander; Pilz, Stefan; Nethander, Maria; Selvin, Elizabeth; Tang, Weihong; Weng, Lu-Chen; Wong, Hoi Suen; Lai, Dongbing; Peacock, Munro; Hannemann, Anke; Völker, Uwe; Homuth, Georg; Nauk, Matthias; Murgia, Federico; Pattee, Jack W; Orwoll, Eric; Zmuda, Joseph M; Riancho, Jose Antonio; Wolf, Myles; Williams, Frances; Penninx, Brenda; Econs, Michael J; Ryan, Kathleen A; Ohlsson, Claes; Paterson, Andrew D; Psaty, Bruce M; Siscovick, David S; Rotter, Jerome I; Pirastu, Mario; Streeten, Elizabeth; März, Winfried; Fox, Caroline; Coresh, Josef; Wallaschofski, Henri; Pankow, James S; de Boer, Ian H; Kestenbaum, Bryan

    2017-05-01

    Parathyroid hormone (PTH) is a primary calcium regulatory hormone. Elevated serum PTH concentrations in primary and secondary hyperparathyroidism have been associated with bone disease, hypertension, and in some studies, cardiovascular mortality. Genetic causes of variation in circulating PTH concentrations are incompletely understood. We performed a genome-wide association study of serum PTH concentrations among 29,155 participants of European ancestry from 13 cohort studies ( n =22,653 and n =6502 in discovery and replication analyses, respectively). We evaluated the association of single nucleotide polymorphisms (SNPs) with natural log-transformed PTH concentration adjusted for age, sex, season, study site, and principal components of ancestry. We discovered associations of SNPs from five independent regions with serum PTH concentration, including the strongest association with rs6127099 upstream of CYP24A1 ( P =4.2 × 10 -53 ), a gene that encodes the primary catabolic enzyme for 1,25-dihydroxyvitamin D and 25-dihydroxyvitamin D. Each additional copy of the minor allele at this SNP associated with 7% higher serum PTH concentration. The other SNPs associated with serum PTH concentration included rs4074995 within RGS14 ( P =6.6 × 10 -17 ), rs219779 adjacent to CLDN14 ( P =3.5 × 10 -16 ), rs4443100 near RTDR1 ( P =8.7 × 10 -9 ), and rs73186030 near CASR ( P =4.8 × 10 -8 ). Of these five SNPs, rs6127099, rs4074995, and rs219779 replicated. Thus, common genetic variants located near genes involved in vitamin D metabolism and calcium and renal phosphate transport associated with differences in circulating PTH concentrations. Future studies could identify the causal variants at these loci, and the clinical and functional relevance of these variants should be pursued. Copyright © 2017 by the American Society of Nephrology.

  16. Complex branchial fistula: a variant arch anomaly.

    Science.gov (United States)

    De Caluwé, D; Hayes, R; McDermott, M; Corbally, M T

    2001-07-01

    A 5-year-old boy presented with an infected left-sided branchial fistula. Despite antibiotic treatment and repeated excision of the fistula, purulent discharge from the wound persisted. Three-dimensional computed tomography (3D CT) reconstruction greatly facilitated the diagnosis and management of this case by showing the course of the fistulous tract. The complexity of the tract suggests that this represents a variant arch anomaly because it contains features of first, second, third, and fourth arch remnants. Copyright 2001 by W.B. Saunders Company.

  17. Anatomy, normal variants, and basic biomechanics

    International Nuclear Information System (INIS)

    Berquist, T.H.; Johnson, K.A.

    1989-01-01

    This paper reports on the anatomy and basic functions of the foot and ankle important to physicians involved in imaging procedures, clinical medicine, and surgery. New radiographic techniques especially magnetic resonance imaging, provide more diagnostic information owing to improved tissue contrast and the ability to obtain multiple image planes (axial, sagittal, coronal, oblique). Therefore, a thorough knowledge of skeletal and soft tissue anatomy is even more essential. Normal variants must also be understood in order to distinguish normal from pathologic changes in the foot and ankle. A basic understanding of biomechanics is also essential for selecting the proper diagnostic techniques

  18. Research progress of behavioral variant frontotemporal dementia

    Directory of Open Access Journals (Sweden)

    Xiao-hua GU

    2015-07-01

    Full Text Available There is no epidemiological data of frontotemporal dementia (FTD in China. The application of updated diagnostic criteria, publishing of frontotemporal lobar degeneration (FTLD consensus in China, development of multimodal imaging and biomarkers promote the clinical understanding on behavioral variant frontotemporal dementia (bvFTD. There is still no drugs treating FTD approved by U.S. Food and Drug Administration (FDA. Multidisciplinary intervention may delay the progression of bvFTD. DOI: 10.3969/j.issn.1672-6731.2015.07.006

  19. Oral fibrolipoma: A rare histological variant

    Directory of Open Access Journals (Sweden)

    Treville Pereira

    2014-01-01

    Full Text Available Lipomas are benign soft tissue mesenchymal neoplasms. Fibrolipoma is a histological variant of lipoma that mostly affects the buccal mucosa and causes functional and cosmetic disabilities. The diagnosis and differentiation of fibrolipoma with clinically similar lesions such as fibroma and pleomorphic adenoma is very essential for a correct treatment plan and complete follow-up. This article presents a case of a 35-year-old female with a fibrolipoma on the lingual marginal gingiva of the mandibular left third molar.

  20. Performance comparison of various time variant filters

    Energy Technology Data Exchange (ETDEWEB)

    Kuwata, M [JEOL Engineering Co. Ltd., Akishima, Tokyo (Japan); Husimi, K

    1996-07-01

    This paper describes the advantage of the trapezoidal filter used in semiconductor detector system comparing with the other time variant filters. The trapezoidal filter is the compose of a rectangular pre-filter and a gated integrator. We indicate that the best performance is obtained by the differential-integral summing type rectangular pre-filter. This filter is not only superior in performance, but also has the useful feature that the rising edge of the output waveform is linear. We introduce an example of this feature used in a high-energy experiment. (author)

  1. Experiments and strategies for the assignment of fully13 C/15N-labelled polypeptides by solid state NMR

    International Nuclear Information System (INIS)

    Straus, Suzana K.; Bremi, Tobias; Ernst, Richard R.

    1998-01-01

    High-resolution heteronuclear NMR correlation experiments and strategies are proposed for the assignment of fully 13 C/ 15 N-labelled polypeptides in the solid state. By the combination of intra-residue and inter-residue 13 C- 15 N correlation experiments with 13 C- 13 C spin-diffusion studies, it becomes feasible to partially assign backbone and side-chain resonances in solid proteins. The performance of sequences using 15 N instead of 13 C detection is evaluated regarding sensitivity and resolution for a labelled dipeptide (L-Val-L-Phe). The techniques are used for a partial assignment of the 15 N and 13 C resonances in human ubiquitin

  2. Effect of apolipoprotein B mRNA-editing catalytic polypeptide-like protein-3G in cervical cancer.

    Science.gov (United States)

    Xu, Yanhua; Leng, Junhong; Xue, Fang; Dong, Ruiqian

    2015-01-01

    Cervical cancer is one of the most common gynecologic cancers. The role of apolipoprotein B mRNA-editing catalytic polypeptide-like protein-3G (APCBEC-3G) in cervical cancer has yet to be elucidated. This study intends to explore the effect of APCBEC-3G on cervical cancer cell proliferation and invasion. In vitro, the cervical cancer cell line Hela was transfected by APCBEC-3G plasmid. The mRNA and protein expression levels of APCBEC-3G were detected by Real-time PCR and Western blot, respectively. Cervical cancer cell proliferation was determined by MTT. Transwell assay was applied to measure the effect of APCBEC-3G on cell invasion. APCBEC-3G mRNA and protein increased significantly after transfection (P3G serves as a suppressor of cervical cancer cell proliferation and invasion. Our research provides theoretical basis for further investigation APOBEC-3G effect in cervical cancer occurrence and development.

  3. Effect of vasoactive intestinal polypeptide and somatostatin on secretion of epidermal growth factor and bicarbonate from Brunner's glands

    DEFF Research Database (Denmark)

    Poulsen, Steen Seier

    1984-01-01

    The effect of VIP and somatostatin on secretion of epidermal growth factor and bicarbonate from Brunner's glands was investigated in the rat. Vasoactive intestinal polypeptide infused in doses of 10 and 100 ng/kg/h significantly increased epidermal growth factor and bicarbonate output......, but the concentrations did not change. Somatostatin infused at doses of 1, 10, 100 and 1000 ng/kg/h against a background of VIP 100 ng/kg/h inhibited in dose-dependent fashion the stimulated epidermal growth factor and bicarbonate outputs from rat Brunner's gland pouches. Also basal secretion was inhibited...... growth factor and bicarbonate from Brunner's glands, an effect which is inhibited by somatostatin. A possible role for somatostatin in the control of Brunner's gland secretion is suggested....

  4. Hyperglycemia acutely lowers the postprandial excursions of glucagon-like Peptide-1 and gastric inhibitory polypeptide in humans

    DEFF Research Database (Denmark)

    Vollmer, Kirsten; Gardiwal, Husai; Menge, Bjoern A

    2009-01-01

    INTRODUCTION: Impaired secretion of glucagon-like peptide 1 (GLP-1) has been suggested to contribute to the deficient incretin effect in patients with type 2 diabetes. It is unclear whether this is a primary defect or a consequence of the hyperglycemia in type 2 diabetes. We examined whether acute...... hyperglycemia reduces the postprandial excursions of gastric inhibitory polypeptide (GIP) and GLP-1, and if so, whether this can be attributed to changes in gastric emptying. PATIENTS AND METHODS: Fifteen nondiabetic individuals participated in a euglycemic clamp and a hyperglycemic clamp experiment, carried...... the hyperglycemic clamp experiments and 83 +/- 3 mg/dl during the euglycemia (P hyperglycemia, but meal ingestion led to a decline in glucose requirements in both experiments (P

  5. Vasoactive intestinal polypeptide excites medial pontine reticular formation neurons in the brainstem rapid eye movement sleep-induction zone

    DEFF Research Database (Denmark)

    Kohlmeier, Kristi Anne; Reiner, P B

    1999-01-01

    Although it has long been known that microinjection of the cholinergic agonist carbachol into the medial pontine reticular formation (mPRF) induces a state that resembles rapid eye movement (REM) sleep, it is likely that other transmitters contribute to mPRF regulation of behavioral states. A key...... candidate is the peptide vasoactive intestinal polypeptide (VIP), which innervates the mPRF and induces REM sleep when injected into this region of the brainstem. To begin understanding the cellular mechanisms underlying this phenomenon, we examined the effects of VIP on mPRF cells using whole-cell patch...... conclude that VIP excites mPRF neurons by activation of a sodium current. This effect is mediated at least in part by G-protein stimulation of adenylyl cyclase, cAMP, and protein kinase A. These data suggest that VIP may play a physiological role in REM induction by its actions on mPRF neurons....

  6. Evaluation of Urinary Nuclear Matrix Protein-22 as Tumor Marker Versus Tissue Polypeptide Specific Antigen in Bilharzial and Bladder Cancer

    International Nuclear Information System (INIS)

    Ahmed, W.A.; El-Kabany, H.

    2004-01-01

    Urinary nuclear matrix protein-22 (NMP-22) and tissue polypeptide specific antigen (TPS) were determined as potential marker for early detection of bladder tumors in patients with high risk (Bilharzial-patients), monitoring and follow up bladder cancer patients. The objective was to determine sensitivity and specificity of markers for bilharzial and cancer lesions. The levels of two parameters were determined pre and post operation. A total of 110 individuals, 20 healthy, 20 bilharzial patients and 70 bladder cancer patients with confirmed diagnosis were investigated. Urine samples were assayed for NMP-22 and TPS test kits. Some bladder cancer patients were selected to follow up. NMP-22 showed highly significant increase (P,0.001) more than TPS (P<0.01) in bladder cancer patients when compared with bilharzial and control group. Overall sensitivity is 7.8% for TPS and 98.5% for NMP-22

  7. Pituitary adenylate cyclase activating polypeptide in stress-related disorders: data convergence from animal and human studies.

    Science.gov (United States)

    Hammack, Sayamwong E; May, Victor

    2015-08-01

    The maladaptive expression and function of several stress-associated hormones have been implicated in pathological stress and anxiety-related disorders. Among these, recent evidence has suggested that pituitary adenylate cyclase activating polypeptide (PACAP) has critical roles in central neurocircuits mediating stress-related emotional behaviors. We describe the PACAPergic systems, the data implicating PACAP in stress biology, and how altered PACAP expression and signaling may result in psychopathologies. We include our work implicating PACAP signaling within the bed nucleus of the stria terminalis in mediating the consequences of stressor exposure and relatedly, describe more recent studies suggesting that PACAP in the central nucleus of the amygdala may impact the emotional aspects of chronic pain states. In aggregate, these results are consistent with data suggesting that PACAP dysregulation is associated with posttraumatic stress disorder in humans. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  8. Membrane Disordering is not Sufficient for Membrane Permeabilization by Islet Amyloidogenic Polypeptide: Studies of IAPP(20-29) Fragments

    Science.gov (United States)

    Brender, Jeffrey R.; Heyl, Deborah L.; Samisetti, Shyamprasad; Kotler, Samuel A.; Osborne, Joshua M.; Pesaru, Ranadheer R.; Ramamoorthy, Ayyalusamy

    2013-01-01

    A key factor in the development of type II diabetes is the loss of insulin-producing beta-cells. Human islet amyloid polypeptide protein (human-IAPP) is believed to play a crucial role in this process by forming small aggregates that exhibit toxicity by disrupting the cell membrane. The actual mechanism of membrane disruption is complex and appears to involve an early component before fiber formation and later component associated with fiber formation on the membrane. By comparing the peptide-lipid interactions derived from solid-state NMR experiments of two IAPP fragments that bind the membrane and cause membrane disordering to IAPP derived peptides known to cause significant early membrane permeabilization, we show here that membrane disordering is not likely to be sufficient by itself to cause the early membrane permeabilization observed by IAPP, and may play a lesser role in IAPP membrane disruption than expected. PMID:23493863

  9. Glucose-dependent insulinotropic polypeptide has impaired effect on abdominal, subcutaneous adipose tissue metabolism in obese subjects

    DEFF Research Database (Denmark)

    Asmar, M; Simonsen, L; Arngrim, N

    2013-01-01

    OBJECTIVE: Glucose-dependent insulinotropic polypeptide (GIP) appears to have a role in lipid metabolism. Recently, we showed that GIP in combination with hyperinsulinemia and hyperglycemia increases triglyceride uptake in abdominal, subcutaneous adipose tissue in lean humans. It has been suggested...... that increased GIP secretion in obesity will promote lipid deposition in adipose tissue. In light of the current attempts to employ GIP antagonists in the treatment and prevention of human obesity, the present experiments were performed in order to elucidate whether the adipose tissue lipid metabolism would...... to an oral glucose challenge: (i) NGT and (ii) IGT. Abdominal, subcutaneous adipose tissue lipid metabolism was studied by conducting measurements of arteriovenous concentrations of metabolites and regional adipose tissue blood flow (ATBF) during GIP (1.5 pmol kg(-1) min(-1)) in combination with a HI...

  10. Survey of familial glaucoma shows a high incidence of cytochrome P450, family 1, subfamily B, polypeptide 1 (CYP1B1) mutations in non-consanguineous congenital forms in a Spanish population

    Science.gov (United States)

    Millá, Elena; Mañé, Begoña; Duch, Susana; Hernan, Imma; Borràs, Emma; Planas, Ester; Dias, Miguel de Sousa; Carballo, Miguel

    2013-01-01

    Purpose To identify myocilin (MYOC) and cytochrome P450, family 1, subfamily B, polypeptide 1 (CYP1B1) mutations in a Spanish population with different clinical forms of familial glaucoma or ocular hypertension (OHT). Methods Index patients from 226 families participated in this study. Patients were diagnosed with familial glaucoma or OHT by complete ophthalmologic examination. Screening for MYOC mutations was performed in 207 index patients: 96 with adult-onset primary open-angle glaucoma (POAG), 21 with primary congenital glaucoma (PCG), 18 with juvenile-onset open-angle glaucoma (JOAG), five with Axenfeld-Rieger syndrome (ARS), and 67 with other types of glaucoma. One hundred two of the families (including all those in whom a MYOC mutation was detected) were also screened for CYP1B1 mutations: 45 POAG, 25 PCG, 21 JOAG, four ARS, and seven others. Results We examined 292 individuals (patients and relatives) with a positive family history of glaucoma or OHT. We identified two novel MYOC variants, p.Lys39Arg and p.Glu218Lys, in two families with POAG, and six previously reported MYOC mutations in seven families with POAG (four), JOAG (one), PCG (one), and normotensive glaucoma (one). CYP1B1 mutations were found in 16 index patients with PCG (nine), POAG (three), JOAG (two), and ARS (two). Conclusions The high percentage (9/25=36%) of mutations in CYP1B1 found in non-consanguineous patients with congenital glaucoma mandates genetic testing. However, the percentage of mutations (9/207=4.4%) in MYOC associated with glaucoma is relatively low in our population. The variable phenotype expression of glaucoma, even in families, cannot be explained with a digenic mechanism between MYOC and CYP1B1. PMID:23922489

  11. The cellular transcription factor CREB corresponds to activating transcription factor 47 (ATF-47) and forms complexes with a group of polypeptides related to ATF-43.

    Science.gov (United States)

    Hurst, H C; Masson, N; Jones, N C; Lee, K A

    1990-12-01

    Promoter elements containing the sequence motif CGTCA are important for a variety of inducible responses at the transcriptional level. Multiple cellular factors specifically bind to these elements and are encoded by a multigene family. Among these factors, polypeptides termed activating transcription factor 43 (ATF-43) and ATF-47 have been purified from HeLa cells and a factor referred to as cyclic AMP response element-binding protein (CREB) has been isolated from PC12 cells and rat brain. We demonstrated that CREB and ATF-47 are identical and that CREB and ATF-43 form protein-protein complexes. We also found that the cis requirements for stable DNA binding by ATF-43 and CREB are different. Using antibodies to ATF-43 we have identified a group of polypeptides (ATF-43) in the size range from 40 to 43 kDa. ATF-43 polypeptides are related by their reactivity with anti-ATF-43, DNA-binding specificity, complex formation with CREB, heat stability, and phosphorylation by protein kinase A. Certain cell types vary in their ATF-43 complement, suggesting that CREB activity is modulated in a cell-type-specific manner through interaction with ATF-43. ATF-43 polypeptides do not appear simply to correspond to the gene products of the ATF multigene family, suggesting that the size of the ATF family at the protein level is even larger than predicted from cDNA-cloning studies.

  12. Vasoactive intestinal polypeptide and peptide histidine methionine. Presence in human follicular fluid and effects on DNA synthesis and steroid secretion in cultured human granulosa/lutein cells

    DEFF Research Database (Denmark)

    Gräs, S; Ovesen, Per Glud; Andersen, A N

    1994-01-01

    Vasoactive intestinal polypeptide (VIP) and peptide histidine methionine (PHM) originate from the same precursor molecule, prepro VIP. In the present study we examined the concentrations of VIP and PHM in human follicular fluid and their effects on cultured human granulosa/lutein cells. Follicula...

  13. The dipeptidyl peptidase 4 inhibitor vildagliptin does not accentuate glibenclamide-induced hypoglycemia but reduces glucose-induced glucagon-like peptide 1 and gastric inhibitory polypeptide secretion

    DEFF Research Database (Denmark)

    El-Ouaghlidi, Andrea; Rehring, Erika; Holst, Jens Juul

    2007-01-01

    BACKGROUND/AIMS: Inhibition of dipeptidyl peptidase 4 by vildagliptin enhances the concentrations of the active form of the incretin hormones glucagon-like peptide 1 (GLP-1) and gastric inhibitory polypeptide (GIP). The present study asked whether vildagliptin accentuates glibenclamide-induced hy...

  14. Pituitary adenylate cyclase activating polypeptide induces vascular relaxation and inhibits non-vascular smooth muscle activity in the rabbit female genital tract

    DEFF Research Database (Denmark)

    Steenstrup, B R; Ottesen, B; Jørgensen, M

    1994-01-01

    In vitro effects of two bioactive forms of pituitary adenylate cyclase activating polypeptide (PACAP): PACAP-38 and PACAP-27 were studied on rabbit vascular and non-vascular smooth muscle. Segments of the ovarian artery and muscle strips from the fallopian tube were used. Two series of experiment...

  15. The Transcriptome of the Zoanthid Protopalythoa variabilis (Cnidaria, Anthozoa) Predicts a Basal Repertoire of Toxin-like and Venom-Auxiliary Polypeptides.

    Science.gov (United States)

    Huang, Chen; Morlighem, Jean-Étienne Rl; Zhou, Hefeng; Lima, Érica P; Gomes, Paula B; Cai, Jing; Lou, Inchio; Pérez, Carlos D; Lee, Simon Ming; Rádis-Baptista, Gandhi

    2016-10-05

    Protopalythoa is a zoanthid that, together with thousands of predominantly marine species, such as hydra, jellyfish, and sea anemones, composes the oldest eumetazoan phylum, i.e., the Cnidaria. Some of these species, such as sea wasps and sea anemones, are highly venomous organisms that can produce deadly toxins for preying, for defense or for territorial disputes. Despite the fact that hundreds of organic and polypeptide toxins have been characterized from sea anemones and jellyfish, practically nothing is known about the toxin repertoire in zoanthids. Here, based on a transcriptome analysis of the zoanthid Protopalythoa variabilis, numerous predicted polypeptides with canonical venom protein features are identified. These polypeptides comprise putative proteins from different toxin families: neurotoxic peptides, hemostatic and hemorrhagic toxins, membrane-active (pore-forming) proteins, protease inhibitors, mixed-function venom enzymes, and venom auxiliary proteins. The synthesis and functional analysis of two of these predicted toxin products, one related to the ShK/Aurelin family and the other to a recently discovered anthozoan toxin, displayed potent in vivo neurotoxicity that impaired swimming in larval zebrafish. Altogether, the complex array of venom-related transcripts that are identified in P. variabilis, some of which are first reported in Cnidaria, provides novel insight into the toxin distribution among species and might contribute to the understanding of composition and evolution of venom polypeptides in toxiferous animals. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  16. Identification of the polypeptides encoded in the unassigned reading frames 2, 4, 4L, and 5 of human mitochondrial DNA

    International Nuclear Information System (INIS)

    Mariottini, P.; Chomyn, A.; Riley, M.; Cottrell, B.; Doolittle, R.F.; Attardi, G.

    1986-01-01

    In previous work, antibodies prepared against chemically synthesized peptides predicted from the DNA sequence were used to identify the polypeptides encoded in three of the eight unassigned reading frames (URFs) of human mitochondrial DNA (mtDNA). In the present study, this approach has been extended to other human mtDNA URFs. In particular, antibodies directed against the NH 2 -terminal octapeptide of the putative URF2 product specifically precipitated component 11 of the HeLa cell mitochondrial translation products, the reaction being inhibited by the specific peptide. Similarly, antibodies directed against the COOH-terminal nonapeptide of the putative URF4 product reacted specifically with components 4 and 5, and antibodies against a COOH-terminal heptapeptide of the presumptive URF4L product reacted specifically with component 26. Antibodies against the NH 2 -terminal heptapeptide of the putative product of URF5 reacted with component 1, but only to a marginal extent; however, the results of a trypsin fingerprinting analysis of component 1 point strongly to this component as being the authentic product of URF5. The polypeptide assignments to the mtDNA URFs analyzed here are supported by the relative electrophoretic mobilities of proteins 11, 4-5, 26, and 1, which are those expected for the molecular weights predicted from the DNA sequence for the products of URF2, URF4, URF4L, and URF5, respectively. With the present assignment, seven of the eight human mtDNA URFs have been shown to be expressed in HeLa cells

  17. Reaction mechanisms in the radiolysis of peptides, polypeptides and proteins II reactions at side-chain loci in model systems

    International Nuclear Information System (INIS)

    Garrison, W.M.

    1983-11-01

    The major emphasis in radiation biology at the molecular level has been on the nucleic acid component of the nucleic acid-protein complex because of its primary genetic importance. But there is increasing evidence that radiation damage to the protein component also has important biological implications. Damage to capsid protein now appears to be a major factor in the radiation inactivation of phage and other viruses. And, there is increasing evidence that radiation-chemical change in the protein component of chromation leads to changes in the stability of the repressor-operator complexes involved in gene expression. Knowledge of the radiation chemistry of protein is also of importance in other fields such as the application of radiation sterilization to foods and drugs. Recent findings that a class of compounds, the α,α'-diaminodicarboxylic acids, not normally present in food proteins, are formed in protein radiolysis is of particular significance since certain of their peptide derivatives have been showing to exhibit immunological activity. The purpose of this review is to bring together and to correlate our present knowledge of products and mechanisms in the radiolysis of peptides, polypeptides and proteins both aqueous and solid-state. In part 1 we presented a discussion of the radiation-induced reactions of the peptide main-chain in model peptide and polypeptide systems. Here in part 2 the emphasis is on the competing radiation chemistry at side-chain loci of peptide derivatives of aliphatic, aromatic-unsaturated and sulfur-containing amino acids in similar systems. Information obtained with the various experimental techniques of product analysis, competition kinetics, spin-trapping, pulse radiolysis, and ESR spectroscopy are included

  18. Causative factors for formation of toxic islet amyloid polypeptide oligomer in type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Jeong HR

    2015-11-01

    Full Text Available Hye Rin Jeong, Seong Soo A AnDepartment of Bionano Technology, Gachon Medical Research Institute, Gachon University, Gyeonggi-do, Republic of KoreaAbstract: Human islet amyloid polypeptide (h-IAPP is a peptide hormone that is synthesized and cosecreted with insulin from insulin-secreting pancreatic β-cells. Recently, h-IAPP was proposed to be the main component responsible for the cytotoxic pancreatic amyloid deposits in patients with type 2 diabetes mellitus (T2DM. Since the causative factors of IAPP (or amylin oligomer aggregation are not fully understood, this review will discuss the various forms of h-IAPP aggregation. Not all forms of IAPP aggregates trigger the destruction of β-cell function and loss of β-cell mass; however, toxic oligomers do trigger these events. Once these toxic oligomers form under abnormal metabolic conditions in T2DM, they can lead to cell disruption by inducing cell membrane destabilization. In this review, the various factors that have been shown to induce toxic IAPP oligomer formation will be presented, as well as the potential mechanism of oligomer and fibril formation from pro-IAPPs. Initially, pro-IAPPs undergo enzymatic reactions to produce the IAPP monomers, which can then develop into oligomers and fibrils. By this mechanism, toxic oligomers could be generated by diverse pathway components. Thus, the interconnections between factors that influence amyloid aggregation (eg, absence of PC2 enzyme, deamidation, reduction of disulfide bonds, environmental factors in the cell, genetic mutations, copper metal ions, and heparin will be presented. Hence, this review will aid in understanding the fundamental causative factors contributing to IAPP oligomer formation and support studies for investigating novel T2DM therapeutic approaches, such as the development of inhibitory agents for preventing oligomerization at the early stages of diabetic pathology.Keywords: amyloid aggregation, causative factor, IAPP, islet

  19. Interactions between crude drug extracts used in Japanese traditional Kampo medicines and organic anion-transporting polypeptide 2B1.

    Science.gov (United States)

    Iijima, Rie; Watanabe, Tomoki; Ishiuchi, Kan'ichiro; Matsumoto, Takashi; Watanabe, Junko; Makino, Toshiaki

    2018-03-25

    The use of herbal medicines has become popular worldwide, and the information on drug interactions between herbal medicines and chemical drugs is needed. We screened the inhibitory effects of crude drugs used in Kampo medicines used in Japan on organic anion-transporting polypeptide (OATP) 2B1 to predict potential interactions between Kampo medicines and chemical drugs used together. We chose 98 kinds of crude drugs frequently used as ingredients of Kampo formulations in Japan and prepared their boiling water extracts. We then screened their inhibitory effects on OATP2B1 by measuring the uptake of estrone 3-sulphate (E3S) by HEK293 cells stably expressing OATP2B1. At the concentration of 100µg/ml, the extracts prepared from 12 kinds of crude drugs, Scuteralliae Radix, Arecae Semen, Aurantii Fructus Immaturus, Perillae Herba, Panacis Japonici Rhizoma, Moutan Cortex, Polygalae Radix, Rhei Rhizoma, Cannabis Fructus, Chrysanthemi Flos, Eriobotryae Folium, and Querci Cortex, suppressed the function of OATP2B1 by less than 20%. The extract of bofutsushosan, a representative Kampo formulation, inhibited OATP2B1 function with sufficient levels to suppress absorption of OATP2B1 substrates in clinics. We further evaluated the inhibitory effects of several ingredients containing Rhei Rhizoma, Perillae Herba, and Moutan Cortex on OATP2B1. Because of crude drugs used in Kampo medicines might suppress absorption of OATP2B1 substrates, these results may contribute to the safe and effective use of Kampo medicine in clinics. A list of abbreviations: EC, (-)-epicatechin; ECG, epicatechin gallate; EGC, epigallocatechin; EGCG, Epigallocatechin gallate; FBS, fetal bovine serum; grapefruit juice; HEK293, Human embryonic kidney; IC 50, The half inhibitory concentration; OATP, organic anion-transporting polypeptide; β-PGG, penta-O-galloyl-β-D-glucose; t.i.d, 3 times a day. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Flavonoids as Inhibitors of Human Butyrylcholinesterase Variants

    Directory of Open Access Journals (Sweden)

    Maja Katalinić

    2014-01-01

    Full Text Available The inhibition of butyrylcholinesterase (BChE, EC 3.1.1.8 appears to be of interest in treating diseases with symptoms of reduced neurotransmitter levels, such as Alzheimer’s disease. However, BCHE gene polymorphism should not be neglected in research since it could have an effect on the expected outcome. Several well-known cholinergic drugs (e.g. galantamine, huperzine and rivastigmine originating from plants, or synthesised as derivatives of plant compounds, have shown that herbs could serve as a source of novel target-directed compounds. We focused our research on flavonoids, biologically active polyphenolic compounds found in many plants and plant-derived products, as BChE inhibitors. All of the tested flavonoids: galangin, quercetin, fisetin and luteolin reversibly inhibited usual, atypical, and fluoride-resistant variants of human BChE. The inhibition potency increased in the following order, identically for all three BChE variants: luteolin

  1. N-terminal and C-terminal heparin-binding domain polypeptides derived from fibronectin reduce adhesion and invasion of liver cancer cells

    International Nuclear Information System (INIS)

    Tang, Nan-Hong; Chen, Yan-Lin; Wang, Xiao-Qian; Li, Xiu-Jin; Wu, Yong; Zou, Qi-Lian; Chen, Yuan-Zhong

    2010-01-01

    Fibronectin (FN) is known to be a large multifunction glycoprotein with binding sites for many substances, including N-terminal and C-terminal heparin-binding domains. We investigated the effects of highly purified rhFNHN29 and rhFNHC36 polypeptides originally cloned from the two heparin-binding domains on the adhesion and invasion of highly metastatic human hepatocellular carcinoma cells (MHCC97H) and analyzed the underlying mechanism involved. The MHCC97H cells that adhered to FN in the presence of various concentrations of rhFNHN29 and rhFNHC36 polypeptides were stained with crystal violet and measured, and the effects of rhFNHN29 and rhFNHC36 on the invasion of the MHCC97H cells were then detected using the Matrigel invasion assay as well as a lung-metastasis mouse model. The expression level of integrins and focal adhesion kinase (FAK) phosphotyrosyl protein was examined by Western blot, and the activity of matrix metalloproteinases (MMPs) and activator protein 1 (AP-1) was analyzed by gelatin zymography and the electrophoretic mobility band-shift assay (EMSA), respectively. Both of the polypeptides rhFNHN29 and rhFNHC36 inhibited adhesion and invasion of MHCC97H cells; however, rhFNHC36 exhibited inhibition at a lower dose than rhFNHN29. These inhibitory effects were mediated by integrin αvβ3 and reversed by a protein tyrosine phosphatase inhibitor. Polypeptides rhFNHN29 and rhFNHC36 abrogated the tyrosine phosphorylation of focal adhesion kinase (p-FAK) and activation of activator protein 1 (AP-1), resulting in the decrease of integrin αv, β3 and β1 expression as well as the reduction of MMP-9 activity. Polypeptides rhFNHN29 and rhFNHC36 could potentially be applicable to human liver cancer as anti-adhesive and anti-invasive agents

  2. Serological Reactivity and Identification of Immunoglobulin E-Binding Polypeptides of Ganoderma applanatum Crude Spore Cytoplasmic Extract in Puerto Rican Subjects.

    Science.gov (United States)

    Vilá-Héreter, Frances; Rivera-Mariani, Félix E; Bolaños-Rosero, Benjamín

    2017-01-01

    The allergenic potential of Ganoderma applanatum basidiospores has been demonstrated previously in Puerto Rico. However, basidiomycete allergens are not available for inclusion in allergy diagnostic panels. Therefore, we sought to confirm allergic sensitization to G. applanatum crude spore cytoplasmic extract through reactivity in serological assays and detection of immunoglobulin E (IgE)-binding polypeptides. Via an indirect ELISA, serological reactivity was compared between groups of individuals with different allergic profiles. Group 1 (n = 51) consisted of individuals with sIgE to the allergens included in the diagnostic panels; group 2 (n = 14) comprised individuals with no sIgE to the allergens tested; and group 3 (n = 22) included individuals with no allergic history. To visualize IgE-binding polypeptides, group 1 sera were examined via Western blotting (WB). Polypeptide bands with the highest reactivity were analyzed by mass spectrometry (MS) for putative identification. The serological reactivity of group 1 was significantly higher than that of group 3 in an indirect ELISA (p = 0.03). Sixty-five percent of group 1 individuals showed reactivity to polypeptide bands in WB. Bands of 81 and 56 kDa had the highest reactivity proportions among the reactive sera, followed by a 45-kDa band. MS analysis of these 3 polypeptides suggests that they are basidiomycete-derived enzymes with aconitate hydratase, catalase, and enolase functions. G. applanatum spores have allergenic components recognized by Puerto Rican individuals, which could eventually be considered as markers in cases of fungal allergy and be included in diagnostic allergen panels in Puerto Rico and tropical regions. © 2017 S. Karger AG, Basel.

  3. Dataset of mitochondrial genome variants in oncocytic tumors

    Directory of Open Access Journals (Sweden)

    Lihua Lyu

    2018-04-01

    Full Text Available This dataset presents the mitochondrial genome variants associated with oncocytic tumors. These data were obtained by Sanger sequencing of the whole mitochondrial genomes of oncocytic tumors and the adjacent normal tissues from 32 patients. The mtDNA variants are identified after compared with the revised Cambridge sequence, excluding those defining haplogroups of our patients. The pathogenic prediction for the novel missense variants found in this study was performed with the Mitimpact 2 program.

  4. A Naturally Occurring Domestic Cat APOBEC3 Variant Confers Resistance to Feline Immunodeficiency Virus Infection.

    Science.gov (United States)

    Yoshikawa, Rokusuke; Izumi, Taisuke; Yamada, Eri; Nakano, Yusuke; Misawa, Naoko; Ren, Fengrong; Carpenter, Michael A; Ikeda, Terumasa; Münk, Carsten; Harris, Reuben S; Miyazawa, Takayuki; Koyanagi, Yoshio; Sato, Kei

    2016-01-01

    Apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3 (APOBEC3; A3) DNA cytosine deaminases can be incorporated into progeny virions and inhibit lentiviral replication. On the other hand, viral infectivity factor (Vif) of lentiviruses antagonizes A3-mediated antiviral activities by degrading A3 proteins. It is known that domestic cat (Felis catus) APOBEC3Z3 (A3Z3), the ortholog of human APOBEC3H, potently suppresses the infectivity of vif-defective feline immunodeficiency virus (FIV). Although a recent report has shown that domestic cat encodes 7 haplotypes (hap I to hap VII) of A3Z3, the relevance of A3Z3 polymorphism in domestic cats with FIV Vif has not yet been addressed. In this study, we demonstrated that these feline A3Z3 variants suppress vif-defective FIV infectivity. We also revealed that codon 65 of feline A3Z3 is a positively selected site and that A3Z3 hap V is subject to positive selection during evolution. It is particularly noteworthy that feline A3Z3 hap V is resistant to FIV Vif-mediated degradation and still inhibits vif-proficient viral infection. Moreover, the side chain size, but not the hydrophobicity, of the amino acid at position 65 determines the resistance to FIV Vif-mediated degradation. Furthermore, phylogenetic analyses have led to the inference that feline A3Z3 hap V emerged approximately 60,000 years ago. Taken together, these findings suggest that feline A3Z3 hap V may have been selected for escape from an ancestral FIV. This is the first evidence for an evolutionary "arms race" between the domestic cat and its cognate lentivirus. Gene diversity and selective pressure are intriguing topics in the field of evolutionary biology. A direct interaction between a cellular protein and a viral protein can precipitate an evolutionary arms race between host and virus. One example is primate APOBEC3G, which potently restricts the replication of primate lentiviruses (e.g., human immunodeficiency virus type 1 [HIV-1] and simian

  5. Characterization of Chlamydomonas reinhardtii Core Histones by Top-Down Mass Spectrometry Reveals Unique Algae-Specific Variants and Post-Translational Modifications.

    Science.gov (United States)

    Khan, Aliyya; Eikani, Carlo K; Khan, Hana; Iavarone, Anthony T; Pesavento, James J

    2018-01-05

    The unicellular microalga Chlamydomonas reinhardtii has played an instrumental role in the development of many new fields (bioproducts, biofuels, etc.) as well as the advancement of basic science (photosynthetic apparati, flagellar function, etc.). Chlamydomonas' versatility ultimately derives from the genes encoded in its genome and the way that the expression of these genes is regulated, which is largely influenced by a family of DNA binding proteins called histones. We characterize C. reinhardtii core histones, both variants and their post-translational modifications, by chromatographic separation, followed by top-down mass spectrometry (TDMS). Because TDMS has not been previously used to study Chlamydomonas proteins, we show rampant artifactual protein oxidation using established nuclei purification and histone extraction methods. After addressing oxidation, both histones H3 and H4 are found to each have a single polypeptide sequence that is minimally acetylated and methylated. Surprisingly, we uncover a novel monomethylation at lysine 79 on histone H4 present on all observed molecules. Histone H2B and H2A are found to have two and three variants, respectively, and both are minimally modified. This study provides an updated assessment of the core histone proteins in the green alga C. reinhardtii by top-down mass spectrometry and lays the foundation for further investigation of these essential proteins.

  6. Full-length VP2 gene analysis of canine parvovirus reveals emergence of newer variants in India.

    Science.gov (United States)

    Nookala, Mangadevi; Mukhopadhyay, Hirak Kumar; Sivaprakasam, Amsaveni; Balasubramanian, Brindhalakshmi; Antony, Prabhakar Xavier; Thanislass, Jacob; Srinivas, Mouttou Vivek; Pillai, Raghavan Madhusoodanan

    2016-12-01

    The canine parvovirus (CPV) infection is a highly contagious and serious enteric disease of dogs with high fatality rate. The present study was taken up to characterize the full-length viral polypeptide 2 (VP2) gene of CPV of Indian origin along with the commercially available vaccines. The faecal samples from parvovirus suspected dogs were collected from various states of India for screening by PCR assay and 66.29% of samples were found positive. Six CPV-2a, three CPV-2b, and one CPV-2c types were identified by sequence analysis. Several unique and existing mutations have been noticed in CPV types analyzed indicating emergence of newer variants of CPV in India. The phylogenetic analysis revealed that all the field CPV types were grouped in different subclades within two main clades, but away from the commercial vaccine strains. CPV-2b and CPV-2c types with unique mutations were found to be establishing in India apart from the prevailing CPV-2a type. Mutations and the positive selection of the mutants were found to be the major mechanism of emergence and evolution of parvovirus. Therefore, the incorporation of local strain in the vaccine formulation may be considered for effective control of CPV infections in India.

  7. Differential Expression Profile of ZFX Variants Discriminates Breast Cancer Subtypes

    Science.gov (United States)

    Pourkeramati, Fatemeh; Asadi, Malek Hossein; Shakeri, Shahryar; Farsinejad, Alireza

    2018-05-13

    ZFX is a transcriptional regulator in embryonic stem cells that plays an important role in pluripotency and self-renewal. ZFX is widely expressed in pluripotent stem cells and is down-regulated during differentiation of embryonic stem cells. ZFX has five different variants that encode three different protein isoforms. While several reports have determined the overexpression of ZFX in a variety of somatic cancers, the expression of ZFX-spliced variants in cancer cells is not well-understood. We investigated the expression of ZFX variants in a series of breast cancer tissues and cell lines using quantitative PCR. The expression of ZFX variant 1/3 was higher in tumor tissue compared to marginal tissue. In contrast, the ZFX variant 5 was down-regulated in tumor tissues. While the ZFX variant 1/3 and ZFX variant 5 expression significantly increased in low-grade tumors, ZFX variant 4 was strongly expressed in high-grade tumors and demonstrating lymphatic invasion. In addition, our result revealed a significant association between the HER2 status and the expression of ZFX-spliced variants. Our data suggest that the expression of ZFX-spliced transcripts varies between different types of breast cancer and may contribute to their tumorigenesis process. Hence, ZFX-spliced transcripts could be considered as novel tumor markers with a probable value in diagnosis, prognosis, and therapy of breast cancer.

  8. Population structure analysis using rare and common functional variants

    Directory of Open Access Journals (Sweden)

    Ding Lili

    2011-11-01

    Full Text Available Abstract Next-generation sequencing technologies now make it possible to genotype and measure hundreds of thousands of rare genetic variations in individuals across the genome. Characterization of high-density genetic variation facilitates control of population genetic structure on a finer scale before large-scale genotyping in disease genetics studies. Population structure is a well-known, prevalent, and important factor in common variant genetic studies, but its relevance in rare variants is unclear. We perform an extensive population structure analysis using common and rare functional variants from the Genetic Analysis Workshop 17 mini-exome sequence. The analysis based on common functional variants required 388 principal components to account for 90% of the variation in population structure. However, an analysis based on rare variants required 532 significant principal components to account for similar levels of variation. Using rare variants, we detected fine-scale substructure beyond the population structure identified using common functional variants. Our results show that the level of population structure embedded in rare variant data is different from the level embedded in common variant data and that correcting for population structure is only as good as the level one wishes to correct.

  9. Human papillomavirus variants among Inuit women in northern Quebec, Canada.

    Science.gov (United States)

    Gauthier, Barbara; Coutlée, Francois; Franco, Eduardo L; Brassard, Paul

    2015-01-01

    Inuit communities in northern Quebec have high rates of human papillomavirus (HPV) infection, cervical cancer and cervical cancer-related mortality as compared to the Canadian population. HPV types can be further classified as intratypic variants based on the extent of homology in their nucleotide sequences. There is limited information on the distribution of intratypic variants in circumpolar areas. Our goal was to describe the HPV intratypic variants and associated baseline characteristics. We collected cervical cell samples in 2002-2006 from 676 Inuit women between the ages of 15 and 69 years in Nunavik. DNA isolates from high-risk HPVs were sequenced to determine the intratypic variant. There were 149 women that were positive for HPVs 16, 18, 31, 33, 35, 45, 52, 56 or 58 during follow-up. There were 5 different HPV16 variants, all of European lineage, among the 57 women positive for this type. There were 8 different variants of HPV18 present and all were of European lineage (n=21). The majority of samples of HPV31 (n=52) were of lineage B. The number of isolates and diversity of the other HPV types was low. Age was the only covariate associated with HPV16 variant category. These frequencies are similar to what was seen in another circumpolar region of Canada, although there appears to be less diversity as only European variants were detected. This study shows that most variants were clustered in one lineage for each HPV type.

  10. Determination of uranium by luminescent method (tablet variant)

    International Nuclear Information System (INIS)

    Sergeev, A.N.; Yufa, B.Ya.

    1985-01-01

    A new tablet variant of luminescent determination of uranium in rocks is developed. The analytical process includes the following operations: sample decomposition, uranium separation from luminescence quencher impurities, preparation of luminescent sample (tablet), photometry of the tablet. The method has two variants developed: the first one is characterized by a more hard decomposition, sample mass being 0.2 g; the second variant has a better detection limit (5x10 -6 %), the sample mass being 0.2-1 g. Procedures of the sample preparation for both variants of analysis are described

  11. Superior and inferior vena cavae: Embryology, variants, and pathology

    International Nuclear Information System (INIS)

    Mendelson, D.S.; Mitty, H.; Janus, C.; Gendal, E.; Berson, B.

    1987-01-01

    The superior and inferior venae cavae may be involved in a host of disease processes. Knowledge of the normal anatomy and variants of these structures is valuable in interpreting plain films and the results of angiographic procedures and all cross-sectional modalities. The authors review the embryology of venae cavae and proceed to describe their normal anatomy and variants. An awareness of the variants can prevent mistaking variants for pathologic processes. Finally, the authors describe pathology involving these vessels and demonstrate the radiographic manifestations

  12. Molecular cloning, genomic organization, chromosome mapping, tissues expression pattern and identification of a novel splicing variant of porcine CIDEb gene

    International Nuclear Information System (INIS)

    Li, YanHua; Li, AiHua; Yang, Z.Q.

    2016-01-01

    Cell death-inducing DNA fragmentation factor-α-like effector b (CIDEb) is a member of the CIDE family of apoptosis-inducing factors, CIDEa and CIDEc have been reported to be Lipid droplets (LDs)-associated proteins that promote atypical LD fusion in adipocytes, and responsible for liver steatosis under fasting and obese conditions, whereas CIDEb promotes lipid storage under normal diet conditions [1], and promotes the formation of triacylglyceride-enriched VLDL particles in hepatocytes [2]. Here, we report the gene cloning, chromosome mapping, tissue distribution, genetic expression analysis, and identification of a novel splicing variant of the porcine CIDEb gene. Sequence analysis shows that the open reading frame of the normal porcine CIDEb isoform covers 660bp and encodes a 219-amino acid polypeptide, whereas its alternative splicing variant encodes a 142-amino acid polypeptide truncated at the fourth exon and comprised of the CIDE-N domain and part of the CIDE-C domain. The deduced amino acid sequence of normal porcine CIDEb shows an 85.8% similarity to the human protein and 80.0% to the mouse protein. The CIDEb genomic sequence spans approximately 6KB comprised of five exons and four introns. Radiation hybrid mapping demonstrated that porcine CIDEb is located at chromosome 7q21 and at a distance of 57cR from the most significantly linked marker, S0334, regions that are syntenic with the corresponding region in the human genome. Tissue expression analysis indicated that normal CIDEb mRNA is ubiquitously expressed in many porcine tissues. It was highly expressed in white adipose tissue and was observed at relatively high levels in the liver, lung, small intestine, lymphatic tissue and brain. The normal version of CIDEb was the predominant form in all tested tissues, whereas the splicing variant was expressed at low levels in all examined tissues except the lymphatic tissue. Furthermore, genetic expression analysis indicated that CIDEb mRNA levels were

  13. Molecular cloning, genomic organization, chromosome mapping, tissues expression pattern and identification of a novel splicing variant of porcine CIDEb gene

    Energy Technology Data Exchange (ETDEWEB)

    Li, YanHua, E-mail: liyanhua.1982@aliyun.com [Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, China International Science and Technology Cooperation base of Child development and Critical Disorders, Children’s Hospital of Chongqing Medical University, Chongqing 400014 (China); Li, AiHua [Chongqing Cancer Institute & Hospital & Cancer Center, Chongqing 404100 (China); Yang, Z.Q. [Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China)

    2016-09-09

    Cell death-inducing DNA fragmentation factor-α-like effector b (CIDEb) is a member of the CIDE family of apoptosis-inducing factors, CIDEa and CIDEc have been reported to be Lipid droplets (LDs)-associated proteins that promote atypical LD fusion in adipocytes, and responsible for liver steatosis under fasting and obese conditions, whereas CIDEb promotes lipid storage under normal diet conditions [1], and promotes the formation of triacylglyceride-enriched VLDL particles in hepatocytes [2]. Here, we report the gene cloning, chromosome mapping, tissue distribution, genetic expression analysis, and identification of a novel splicing variant of the porcine CIDEb gene. Sequence analysis shows that the open reading frame of the normal porcine CIDEb isoform covers 660bp and encodes a 219-amino acid polypeptide, whereas its alternative splicing variant encodes a 142-amino acid polypeptide truncated at the fourth exon and comprised of the CIDE-N domain and part of the CIDE-C domain. The deduced amino acid sequence of normal porcine CIDEb shows an 85.8% similarity to the human protein and 80.0% to the mouse protein. The CIDEb genomic sequence spans approximately 6KB comprised of five exons and four introns. Radiation hybrid mapping demonstrated that porcine CIDEb is located at chromosome 7q21 and at a distance of 57cR from the most significantly linked marker, S0334, regions that are syntenic with the corresponding region in the human genome. Tissue expression analysis indicated that normal CIDEb mRNA is ubiquitously expressed in many porcine tissues. It was highly expressed in white adipose tissue and was observed at relatively high levels in the liver, lung, small intestine, lymphatic tissue and brain. The normal version of CIDEb was the predominant form in all tested tissues, whereas the splicing variant was expressed at low levels in all examined tissues except the lymphatic tissue. Furthermore, genetic expression analysis indicated that CIDEb mRNA levels were

  14. A rabies virus vampire bat variant shows increased neuroinvasiveness in mice when compared to a carnivore variant.

    Science.gov (United States)

    Mesquita, Leonardo Pereira; Gamon, Thais Helena Martins; Cuevas, Silvia Elena Campusano; Asano, Karen Miyuki; Fahl, Willian de Oliveira; Iamamoto, Keila; Scheffer, Karin Correa; Achkar, Samira Maria; Zanatto, Dennis Albert; Mori, Cláudia Madalena Cabrera; Maiorka, Paulo César; Mori, Enio

    2017-12-01

    Rabies is one of the most important zoonotic diseases and is caused by several rabies virus (RABV) variants. These variants can exhibit differences in neurovirulence, and few studies have attempted to evaluate the neuroinvasiveness of variants derived from vampire bats and wild carnivores. The aim of this study was to evaluate the neuropathogenesis of infection with two Brazilian RABV street variants (variant 3 and crab-eating fox) in mice. BALB/c mice were inoculated with RABV through the footpad, with the 50% mouse lethal dose (LD 50 ) determined by intracranial inoculation. The morbidity of rabies in mice infected with variant 3 and the crab-eating fox strain was 100% and 50%, respectively, with an incubation period of 7 and 6 days post-inoculation (dpi), respectively. The clinical disease in mice was similar with both strains, and it was characterized initially by weight loss, ruffled fur, hunched posture, and hind limb paralysis progressing to quadriplegia and recumbency at 9 to 12 dpi. Histological lesions within the central nervous system (CNS) characterized by nonsuppurative encephalomyelitis with neuronal degeneration and necrosis were observed in mice infected with variant 3 and those infected with the crab-eating fox variant. However, lesions and the presence of RABV antigen, were more widespread within the CNS of variant-3-infected mice, whereas in crab-eating fox-variant-infected mice, RABV antigens were more restricted to caudal areas of the CNS, such as the spinal cord and brainstem. In conclusion, the results shown here demonstrate that the RABV vampire bat strain (variant 3) has a higher potential for neuroinvasiveness than the carnivore variant.

  15. Hepatic uptake of conjugated bile acids is mediated by both sodium taurocholate cotransporting polypeptide and organic anion transporting polypeptides and modulated by intestinal sensing of plasma bile acid levels in mice.

    Science.gov (United States)

    Slijepcevic, Davor; Roscam Abbing, Reinout L P; Katafuchi, Takeshi; Blank, Antje; Donkers, Joanne M; van Hoppe, Stéphanie; de Waart, Dirk R; Tolenaars, Dagmar; van der Meer, Jonathan H M; Wildenberg, Manon; Beuers, Ulrich; Oude Elferink, Ronald P J; Schinkel, Alfred H; van de Graaf, Stan F J

    2017-11-01

    The Na + -taurocholate cotransporting polypeptide (NTCP/SLC10A1) is believed to be pivotal for hepatic uptake of conjugated bile acids. However, plasma bile acid levels are normal in a subset of NTCP knockout mice and in mice treated with myrcludex B, a specific NTCP inhibitor. Here, we elucidated which transport proteins mediate the hepatic uptake of conjugated bile acids and demonstrated intestinal sensing of elevated bile acid levels in plasma in mice. Mice or healthy volunteers were treated with myrcludex B. Hepatic bile acid uptake kinetics were determined in wild-type (WT), organic anion transporting polypeptide (OATP) knockout mice (lacking Slco1a/1b isoforms), and human OATP1B1-transgenic mice. Effects of fibroblast growth factor 19 (FGF19) on hepatic transporter mRNA levels were assessed in rat hepatoma cells and in mice by peptide injection or adeno-associated virus-mediated overexpression. NTCP inhibition using myrcludex B had only moderate effects on bile acid kinetics in WT mice, but completely inhibited active transport of conjugated bile acid species in OATP knockout mice. Cholesterol 7α-hydroxylase Cyp7a1 expression was strongly down-regulated upon prolonged inhibition of hepatic uptake of conjugated bile acids. Fgf15 (mouse counterpart of FGF19) expression was induced in hypercholanemic OATP and NTCP knockout mice, as well as in myrcludex B-treated cholestatic mice, whereas plasma FGF19 was not induced in humans treated with myrcludex B. Fgf15/FGF19 expression was induced in polarized human enterocyte-models and mouse organoids by basolateral incubation with a high concentration (1 mM) of conjugated bile acids. NTCP and OATPs contribute to hepatic uptake of conjugated bile acids in mice, whereas the predominant uptake in humans is NTCP mediated. Enterocytes sense highly elevated levels of (conjugated) bile acids in the systemic circulation to induce FGF15/19, which modulates hepatic bile acid synthesis and uptake. (Hepatology 2017;66:1631-1643).

  16. Variant facial artery in the submandibular region.

    Science.gov (United States)

    Vadgaonkar, Rajanigandha; Rai, Rajalakshmi; Prabhu, Latha V; Bv, Murlimanju; Samapriya, Neha

    2012-07-01

    Facial artery has been considered to be the most important vascular pedicle in facial rejuvenation procedures and submandibular gland (SMG) resection. It usually arises from the external carotid artery and passes from the carotid to digastric triangle, deep to the posterior belly of digastric muscle, and lodges in a groove at the posterior end of the SMG. It then passes between SMG and the mandible to reach the face after winding around the base of the mandible. During a routine dissection, in a 62-year-old female cadaver, in Kasturba Medical College Mangalore, an unusual pattern in the cervical course of facial artery was revealed. The right facial artery was found to pierce the whole substance of the SMG before winding around the lower border of the mandible to enter the facial region. Awareness of existence of such a variant and its comparison to the normal anatomy will be useful to oral and maxillofacial surgeons.

  17. Fast Ordered Sampling of DNA Sequence Variants

    Directory of Open Access Journals (Sweden)

    Anthony J. Greenberg

    2018-05-01

    Full Text Available Explosive growth in the amount of genomic data is matched by increasing power of consumer-grade computers. Even applications that require powerful servers can be quickly tested on desktop or laptop machines if we can generate representative samples from large data sets. I describe a fast and memory-efficient implementation of an on-line sampling method developed for tape drives 30 years ago. Focusing on genotype files, I test the performance of this technique on modern solid-state and spinning hard drives, and show that it performs well compared to a simple sampling scheme. I illustrate its utility by developing a method to quickly estimate genome-wide patterns of linkage disequilibrium (LD decay with distance. I provide open-source software that samples loci from several variant format files, a separate program that performs LD decay estimates, and a C++ library that lets developers incorporate these methods into their own projects.

  18. Fast Ordered Sampling of DNA Sequence Variants.

    Science.gov (United States)

    Greenberg, Anthony J

    2018-05-04

    Explosive growth in the amount of genomic data is matched by increasing power of consumer-grade computers. Even applications that require powerful servers can be quickly tested on desktop or laptop machines if we can generate representative samples from large data sets. I describe a fast and memory-efficient implementation of an on-line sampling method developed for tape drives 30 years ago. Focusing on genotype files, I test the performance of this technique on modern solid-state and spinning hard drives, and show that it performs well compared to a simple sampling scheme. I illustrate its utility by developing a method to quickly estimate genome-wide patterns of linkage disequilibrium (LD) decay with distance. I provide open-source software that samples loci from several variant format files, a separate program that performs LD decay estimates, and a C++ library that lets developers incorporate these methods into their own projects. Copyright © 2018 Greenberg.

  19. Genetic variants in periodontal health and disease

    Energy Technology Data Exchange (ETDEWEB)

    Dumitrescu, Alexandrina L [Tromsoe Univ. (Norway). Inst. of Clinical Dentistry; Kobayashi, Junya [Kyoto Univ. (Japan). Dept. of Genome Repair Dynamics

    2010-07-01

    Periodontitis is a complex, multifactorial disease and its susceptibility is genetically determined. The present book systematically reviews the evidence of the association between the genetic variants and periodontitis progression and/or treatment outcomes. Genetic syndromes known to be associated with periodontal disease, the candidate gene polymorphisms investigated in relation to periodontitis, the heritability of chronic and aggressive periodontitis, as well as common guidelines for association studies are described. This growing understanding of the role of genetic variation in inflammation and periodontal chronic disease presents opportunities to identify healthy persons who are at increased risk of disease and to potentially modify the trajectory of disease to prolong healthy aging. The book represents a new concept in periodontology with its pronounced focus on understanding through knowledge rather than presenting the presently valid answers. Connections between genetics and periodontology are systematically reviewed and covered in detail. (orig.)

  20. Nuclear variants of bone morphogenetic proteins

    Directory of Open Access Journals (Sweden)

    Meinhart Christopher A

    2010-03-01

    Full Text Available Abstract Background Bone morphogenetic proteins (BMPs contribute to many different aspects of development including mesoderm formation, heart development, neurogenesis, skeletal development, and axis formation. They have previously been recognized only as secreted growth factors, but the present study detected Bmp2, Bmp4, and Gdf5/CDMP1 in the nuclei of cultured cells using immunocytochemistry and immunoblotting of nuclear extracts. Results In all three proteins, a bipartite nuclear localization signal (NLS was found to overlap the site at which the proproteins are cleaved to release the mature growth factors from the propeptides. Mutational analyses indicated that the nuclear variants of these three proteins are produced by initiating translation from downstream alternative start codons. The resulting proteins lack N-terminal signal peptides and are therefore translated in the cytoplasm rather than the endoplasmic reticulum, thus avoiding proteolytic processing in the secretory pathway. Instead, the uncleaved proteins (designated nBmp2, nBmp4, and nGdf5 containing the intact NLSs are translocated to the nucleus. Immunostaining of endogenous nBmp2 in cultured cells demonstrated that the amount of nBmp2 as well as its nuclear/cytoplasmic distribution differs between cells that are in M-phase versus other phases of the cell cycle. Conclusions The observation that nBmp2 localization varies throughout the cell cycle, as well as the conservation of a nuclear localization mechanism among three different BMP family members, suggests that these novel nuclear variants of BMP family proteins play an important functional role in the cell.

  1. A variant upstream of HLA-DRB1 and multiple variants in MICA influence susceptibility to cervical cancer in a Swedish population

    International Nuclear Information System (INIS)

    Chen, Dan; Hammer, Joanna; Lindquist, David; Idahl, Annika; Gyllensten, Ulf

    2014-01-01

    In a genome-wide association study, we have previously identified and performed the initial replication of three novel susceptibility loci for cervical cancer: rs9272143 upstream of HLA-DRB1, rs2516448 adjacent to MHC class I polypeptide-related sequence A gene (MICA), and rs3117027 at HLA-DPB2. The risk allele T of rs2516448 is in perfect linkage disequilibrium with a frameshift mutation (A5.1) in MICA exon 5, which results in a truncated protein. To validate these associations in an independent study and extend our prior work to MICA exon 5, we genotyped the single-nucleotide polymorphisms at rs9272143, rs2516448, rs3117027 and the MICA exon 5 microsatellite in a nested case–control study of 961 cervical cancer patients (827 carcinoma in situ and 134 invasive carcinoma) and 1725 controls from northern Sweden. The C allele of rs9272143 conferred protection against cervical cancer (odds ratio [OR] = 0.73, 95% confidence interval [CI] = 0.65–0.82; P = 1.6 × 10 −7 ), which is associated with higher expression level of HLA-DRB1, whereas the T allele of rs2516448 increased the susceptibility to cervical cancer (OR = 1.33, 95% CI = 1.19–1.49; P = 5.8 × 10 −7 ), with the same association shown with MICA-A5.1. The direction and the magnitude of these associations were consistent with our previous findings. We also identified protective effects of the MICA-A4 (OR = 0.80, 95% CI = 0.68–0.94; P = 6.7 × 10 −3 ) and MICA-A5 (OR = 0.60, 95% CI = 0.50–0.72; P = 3.0 × 10 −8 ) alleles. The associations with these variants are unlikely to be driven by the nearby human leukocyte antigen (HLA) alleles. No association was observed between rs3117027 and risk of cervical cancer. Our results support the role of HLA-DRB1 and MICA in the pathogenesis of cervical cancer

  2. Re-Ranking Sequencing Variants in the Post-GWAS Era for Accurate Causal Variant Identification

    Science.gov (United States)

    Faye, Laura L.; Machiela, Mitchell J.; Kraft, Peter; Bull, Shelley B.; Sun, Lei

    2013-01-01

    Next generation sequencing has dramatically increased our ability to localize disease-causing variants by providing base-pair level information at costs increasingly feasible for the large sample sizes required to detect complex-trait associations. Yet, identification of causal variants within an established region of association remains a challenge. Counter-intuitively, certain factors that increase power to detect an associated region can decrease power to localize the causal variant. First, combining GWAS with imputation or low coverage sequencing to achieve the large sample sizes required for high power can have the unintended effect of producing differential genotyping error among SNPs. This tends to bias the relative evidence for association toward better genotyped SNPs. Second, re-use of GWAS data for fine-mapping exploits previous findings to ensure genome-wide significance in GWAS-associated regions. However, using GWAS findings to inform fine-mapping analysis can bias evidence away from the causal SNP toward the tag SNP and SNPs in high LD with the tag. Together these factors can reduce power to localize the causal SNP by more than half. Other strategies commonly employed to increase power to detect association, namely increasing sample size and using higher density genotyping arrays, can, in certain common scenarios, actually exacerbate these effects and further decrease power to localize causal variants. We develop a re-ranking procedure that accounts for these adverse effects and substantially improves the accuracy of causal SNP identification, often doubling the probability that the causal SNP is top-ranked. Application to the NCI BPC3 aggressive prostate cancer GWAS with imputation meta-analysis identified a new top SNP at 2 of 3 associated loci and several additional possible causal SNPs at these loci that may have otherwise been overlooked. This method is simple to implement using R scripts provided on the author's website. PMID:23950724

  3. Genomewide association study identifies no major founder variant in ...

    Indian Academy of Sciences (India)

    2013-12-10

    Dec 10, 2013 ... variant in Caucasian moyamoya disease ... 1Department of Health and Environmental Sciences, Kyoto University Graduate ... a low prevalence in European countries (Goto and Yonekawa. 1992; Kuroda and Houkin 2008). We have found that the p.R4810K variant in the ring finger protein 213 (RNF213).

  4. Managing Process Variants in the Process Life Cycle

    NARCIS (Netherlands)

    Hallerbach, A.; Bauer, Th.; Reichert, M.U.

    2007-01-01

    When designing process-aware information systems, often variants of the same process have to be specified. Each variant then constitutes an adjustment of a particular process to specific requirements building the process context. Current Business Process Management (BPM) tools do not adequately

  5. Germline Variants of Prostate Cancer in Japanese Families.

    Directory of Open Access Journals (Sweden)

    Takahide Hayano

    Full Text Available Prostate cancer (PC is the second most common cancer in men. Family history is the major risk factor for PC. Only two susceptibility genes were identified in PC, BRCA2 and HOXB13. A comprehensive search of germline variants for patients with PC has not been reported in Japanese families. In this study, we conducted exome sequencing followed by Sanger sequencing to explore responsible germline variants in 140 Japanese patients with PC from 66 families. In addition to known susceptibility genes, BRCA2 and HOXB13, we identified TRRAP variants in a mutually exclusive manner in seven large PC families (three or four patients per family. We also found shared variants of BRCA2, HOXB13, and TRRAP from 59 additional small PC families (two patients per family. We identified two deleterious HOXB13 variants (F127C and G132E. Further exploration of the shared variants in rest of the families revealed deleterious variants of the so-called cancer genes (ATP1A1, BRIP1, FANCA, FGFR3, FLT3, HOXD11, MUTYH, PDGFRA, SMARCA4, and TCF3. The germline variant profile provides a new insight to clarify the genetic etiology and heterogeneity of PC among Japanese men.

  6. Holographic representation of space-variant systems: system theory.

    Science.gov (United States)

    Marks Ii, R J; Krile, T F

    1976-09-01

    System theory for holographic representation of linear space-variant systems is derived. The utility of the resulting piecewise isoplanatic approximation (PIA) is illustrated by example application to the invariant system, ideal magnifier, and Fourier transformer. A method previously employed to holographically represent a space-variant system, the discrete approximation, is shown to be a special case of the PIA.

  7. Detecting rare variants in case-parents association studies.

    Directory of Open Access Journals (Sweden)

    Kuang-Fu Cheng

    Full Text Available Despite the success of genome-wide association studies (GWASs in detecting common variants (minor allele frequency ≥0.05 many suggested that rare variants also contribute to the genetic architecture of diseases. Recently, researchers demonstrated that rare variants can show a strong stratification which may not be corrected by using existing methods. In this paper, we focus on a case-parents study and consider methods for testing group-wise association between multiple rare (and common variants in a gene region and a disease. All tests depend on the numbers of transmitted mutant alleles from parents to their diseased children across variants and hence they are robust to the effect of population stratification. We use extensive simulation studies to compare the performance of four competing tests: the largest single-variant transmission disequilibrium test (TDT, multivariable test, combined TDT, and a likelihood ratio test based on a random-effects model. We find that the likelihood ratio test is most powerful in a wide range of settings and there is no negative impact to its power performance when common variants are also included in the analysis. If deleterious and protective variants are simultaneously analyzed, the likelihood ratio test was generally insensitive to the effect directionality, unless the effects are extremely inconsistent in one direction.

  8. Androgen Receptor Splice Variants and Resistance to Taxane Chemotherapy

    Science.gov (United States)

    2017-10-01

    resistant prostate cancer ; docetaxel; cabazitaxel; chemotherapy; androgen receptor splice variants; microtubule; ligand-binding domain; microtubule... receptor splice variants (AR-Vs) are associated with resistance to taxane chemotherapy in castration- resistant prostate cancer (CRPC). However, this...androgen receptor inhibitors in prostate cancer . Nat Rev Cancer . 2015;15:701–11.

  9. Hepatitis E Virus Variant in Farmed Mink, Denmark

    DEFF Research Database (Denmark)

    Krog, Jesper Schak; Breum, Solvej Østergaard; Jensen, Trine Hammer

    2013-01-01

    Hepatitis E virus (HEV) is a zoonotic virus for which pigs are the primary animal reservoir. To investigate whether HEV occurs in mink in Denmark, we screened feces and tissues from domestic and wild mink. Our finding of a novel HEV variant supports previous findings of HEV variants in a variety...

  10. Variant Creutzfeldt-Jakob Disease (vCJD)

    Science.gov (United States)

    ... Form Controls Cancel Submit Search the CDC Variant Creutzfeldt-Jakob Disease (vCJD) Note: Javascript is disabled or is not ... gov . Recommend on Facebook Tweet Share Compartir Variant Creutzfeldt-Jakob disease (vCJD) is a prion disease that was first ...

  11. Genetics Home Reference: GM2-gangliosidosis, AB variant

    Science.gov (United States)

    ... Resources Genetic Testing (1 link) Genetic Testing Registry: Tay-Sachs disease, variant AB General Information from MedlinePlus (5 links) ... AB variant Activator Deficiency/GM2 Gangliosidosis Activator-deficient Tay-Sachs disease GM2 Activator Deficiency Disease GM2 gangliosidosis, type AB ...

  12. Assessment of Functional Effects of Unclassified Genetic Variants

    NARCIS (Netherlands)

    Couch, Fergus J.; Rasmussen, Lene Juel; Hofstra, Robert; Monteiro, Alvaro N. A.; Greenblatt, Marc S.; de Wind, Niels

    2008-01-01

    Inherited predisposition to disease is often linked to reduced activity of a disease associated gene product. Thus, quantitation of the influence of inherited variants on gene function can potentially be used to predict the disease relevance of these variants. While many disease genes have been

  13. Assessment of Functional Effects of Unclassified Genetic Variants

    NARCIS (Netherlands)

    Couch, Fergus J.; Rasmussen, Lene Juel; Hofstra, Robert; Monteiro, Alvaro N. A.; Greenblatt, Marc S.; de Wind, Niels

    Inherited predisposition to disease is often linked to reduced activity of a disease associated gene product. Thus, quantitation of the influence of inherited variants on gene function can potentially be used to predict the disease relevance of these variants. While many disease genes have been

  14. Association analysis identifies ZNF750 regulatory variants in psoriasis

    Directory of Open Access Journals (Sweden)

    Birnbaum Ramon Y

    2011-12-01

    Full Text Available Abstract Background Mutations in the ZNF750 promoter and coding regions have been previously associated with Mendelian forms of psoriasis and psoriasiform dermatitis. ZNF750 encodes a putative zinc finger transcription factor that is highly expressed in keratinocytes and represents a candidate psoriasis gene. Methods We examined whether ZNF750 variants were associated with psoriasis in a large case-control population. We sequenced the promoter and exon regions of ZNF750 in 716 Caucasian psoriasis cases and 397 Caucasian controls. Results We identified a total of 47 variants, including 38 rare variants of which 35 were novel. Association testing identified two ZNF750 haplotypes associated with psoriasis (p ZNF750 promoter and 5' UTR variants displayed a 35-55% reduction of ZNF750 promoter activity, consistent with the promoter activity reduction seen in a Mendelian psoriasis family with a ZNF750 promoter variant. However, the rare promoter and 5' UTR variants identified in this study did not strictly segregate with the psoriasis phenotype within families. Conclusions Two haplotypes of ZNF750 and rare 5' regulatory variants of ZNF750 were found to be associated with psoriasis. These rare 5' regulatory variants, though not causal, might serve as a genetic modifier of psoriasis.

  15. ADULT VARIANT BARTTER’S SYNDROME- A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Ishwar Sidappa Hasabi

    2017-02-01

    Full Text Available BACKGROUND Bartter syndrome is a group of channelopathies with different genetic origins and molecular pathophysiologies, but sharing common feature of decreased tubular transport of sodium chloride in thick ascending loop of Henle (TAL, 1 although more common in antenatal group. Classic adult variant of Bartter syndrome is a rare entity. We hereby present a rare adult variant of classic Bartter syndrome.

  16. In-situ crosslinkable and self-assembling elastin-like polypeptide block copolymers for cartilage tissue repair

    Science.gov (United States)

    Lim, Dong Woo

    This work describes the development of genetically engineered elastin-like polypeptide (ELP) block copolymers as in-situ gelling scaffolds for cartilage tissue repair. The central hypothesis underlying this work is that ELP based biopolymers can be exploited as injectable biomaterials by rapid chemical crosslinking. To prove this, gene libraries encoding ELP having different molecular weights and amino acid sequences, and ELP block copolymers composed of various ELP blocks having diverse amino acid composition, length, and phase transition behavior were synthesized by recursive directional ligation, expressed in E. Coli and purified by inverse transition cycling. Mannich-type condensation of hydroxymethylphosphines (HMPs) with primary- and secondary-amines of amino acids was developed as a new crosslinking method of polypeptides. Chemically crosslinked ELP hydrogels were formed rapidly in an aqueous solution by reaction of ELPs containing periodic lysine residues with HMPs. The crosslinking density and mechanical property of the ELP hydrogels were controlled at the sequence level by varying the Lys density in ELPs composed of mono-block as well as by segregation of the Lys residues within specific blocks of tri-block architectures. Fibroblasts embedded in ELP hydrogels survived the crosslinking process and were viable after in vitro culture for at least 3 days. The DNA content of fibroblasts within the tri-block gels was significantly higher than that in the mono-block gels at day 3. These results suggest that the HMP crosslinked ELP block copolymer hydrogels show finely tuned mechanical properties and different microenvironments for cell viability as well as potential as in-situ crosslinkable biopolymers for tissue repair applications with load-bearing environments. As an alternative, rheological behavior of the ELP block copolymers and ELP-grafted hyaluronic acids (HAs) as artificial extracellular matrices (ECMs) showed that they were thermally aggregated into

  17. Dock 'n roll: folding of a silk-inspired polypeptide into an amyloid-like beta solenoid.

    Science.gov (United States)

    Zhao, Binwu; Cohen Stuart, Martien A; Hall, Carol K

    2016-04-20

    Polypeptides containing the motif ((GA)mGX)n occur in silk and have a strong tendency to self-assemble. For example, polypeptides containing (GAGAGAGX)n, where X = G or H have been observed to form filaments; similar sequences but with X = Q have been used in the design of coat proteins (capsids) for artificial viruses. The structure of the (GAGAGAGX)m filaments has been proposed to be a stack of peptides in a β roll structure with the hydrophobic side chains pointing outwards (hydrophobic shell). Another possible configuration, a β roll or β solenoid structure which has its hydrophobic side chains buried inside (hydrophobic core) was, however, overlooked. We perform ground state analysis as well as atomic-level molecular dynamics simulations, both on single molecules and on two-molecule stacks of the silk-inspired sequence (GAGAGAGQ)10, to decide whether the hydrophobic core or the hydrophobic shell configuration is the most stable one. We find that a stack of two hydrophobic core molecules is energetically more favorable than a stack of two hydrophobic shell molecules. A shell molecule initially placed in a perfect β roll structure tends to rotate its strands, breaking in-plane hydrogen bonds and forming out-of-plane hydrogen bonds, while a core molecule stays in the β roll structure. The hydrophobic shell structure has type II' β turns whereas the core configuration has type II β turns; only the latter secondary structure agrees well with solid-state NMR experiments on a similar sequence (GA)15. We also observe that the core stack has a higher number of intra-molecular hydrogen bonds and a higher number of hydrogen bonds between stack and water than the shell stack. Hence, we conclude that the hydrophobic core configuration is the most likely structure. In the stacked state, each peptide has more intra-molecular hydrogen bonds than a single folded molecule, which suggests that stacking provides the extra stability needed for molecules to reach the folded

  18. Dock ’n Roll: Folding of a Silk-Inspired Polypeptide into an Amyloid-like Beta Solenoid

    Science.gov (United States)

    Zhao, Binwu; Cohen Stuart, Martien A.; Hall, Carol K.

    2016-01-01

    Polypeptides containing the motif ((GA)mGX)n occur in silk (we refer to them as ‘silk-like’) and have a strong tendency to self-assemble. For example, polypeptides containing (GAGAGAGX)n, where X = G or H have been observed to form filaments; similar sequences but with X = Q have been used in the design of coat proteins (capsids) for artificial viruses. The structure of the (GAGAGAGX)m filaments has been proposed to be a stack of peptides in a β roll structure with the hydrophobic side chains pointing outwards (hydrophobic shell). Another possible configuration, a β roll or β solenoid structure which has its hydrophobic side chains buried inside (hydrophobic core) was, however, overlooked. We perform ground state analysis as well as atomic-level molecular dynamics simulations, both on single molecules and on two-molecule stacks of the silk-inspired sequence (GAGAGAGQ)10, to decide whether the hydrophobic core or the hydrophobic shell configuration is the most stable one. We find that a stack of two hydrophobic core molecules is energetically more favorable than a stack of two shell molecules. A shell molecule initially placed in a perfect β roll structure tends to rotate its strands, breaking in-plane hydrogen bonds and forming out-of-plane hydrogen bonds, while a core molecule stays in the β roll structure. The hydrophobic shell structure has type II’ β turns whereas the core configuration has type II β turns; only the latter secondary structure agrees well with solid-state NMR experiments on a similar sequence (GA)15. We also observe that the core stack has a higher number of intra-molecular hydrogen bonds and a higher number of hydrogen bonds between stack and water than the shell stack. Hence, we conclude that the hydrophobic core configuration is the most likely structure. In the stacked state, each peptide has more intra-molecular hydrogen bonds than a single folded molecule, which suggests that stacking provides the extra stability needed for

  19. Combinations of Genetic Variants Occurring Exclusively in Patients

    Directory of Open Access Journals (Sweden)

    Erling Mellerup

    Full Text Available In studies of polygenic disorders, scanning the genetic variants can be used to identify variant combinations. Combinations that are exclusively found in patients can be separated from those combinations occurring in control persons. Statistical analyses can be performed to determine whether the combinations that occur exclusively among patients are significantly associated with the investigated disorder. This research strategy has been applied in materials from various polygenic disorders, identifying clusters of patient-specific genetic variant combinations that are significant associated with the investigated disorders. Combinations from these clusters are found in the genomes of up to 55% of investigated patients, and are not present in the genomes of any control persons. Keywords: Genetic variants, Polygenic disorder, Combinations of genetic variants, Patient-specific combinations

  20. Golden Rule of Morphology and Variants of Word forms

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    Hlaváčová Jaroslava

    2017-12-01

    Full Text Available In many languages, some words can be written in several ways. We call them variants. Values of all their morphological categories are identical, which leads to an identical morphological tag. Together with the identical lemma, we have two or more wordforms with the same morphological description. This ambiguity may cause problems in various NLP applications. There are two types of variants – those affecting the whole paradigm (global variants and those affecting only wordforms sharing some combinations of morphological values (inflectional variants. In the paper, we propose means how to tag all wordforms, including their variants, unambiguously. We call this requirement “Golden rule of morphology”. The paper deals mainly with Czech, but the ideas can be applied to other languages as well.

  1. Electrophoretic variants of blood proteins in Japanese, 7

    International Nuclear Information System (INIS)

    Satoh, Chiyoko; Takahashi, Norio; Kimura, Yasukazu; Miura, Akiko; Kaneko, Junko; Fujita, Mikio; Toyama, Kyoko.

    1986-11-01

    A total of 16,835 children, of whom 11,737 are unrelated, from Hiroshima and Nagasaki were examined for erythrocyte cytoplasmic glutamate-oxaloacetate transaminase (GOT1) by starch gel electrophoresis. A variant allele named GOT1*2HR1 which seems to be identical with GOT1*2 was encountered in polymorphic frequency. Five kinds of rare variants, 3NG1, 4NG1, 5NG1, 6HR1, and 7NG1 were encountered in a total of 109 children. Except for 7NG1 for which complete family study was unable, family studies confirmed the genetic nature of these rare variants, since for all instances in which both parents could be examined, one of the parents exhibited the same variant as that of their child. Thermostability profiles of these six variants were normal. The enzyme activities of five were decreased, while the value of one was normal compared to that of GOT1 1. (author)

  2. Bayesian detection of causal rare variants under posterior consistency.

    KAUST Repository

    Liang, Faming

    2013-07-26

    Identification of causal rare variants that are associated with complex traits poses a central challenge on genome-wide association studies. However, most current research focuses only on testing the global association whether the rare variants in a given genomic region are collectively associated with the trait. Although some recent work, e.g., the Bayesian risk index method, have tried to address this problem, it is unclear whether the causal rare variants can be consistently identified by them in the small-n-large-P situation. We develop a new Bayesian method, the so-called Bayesian Rare Variant Detector (BRVD), to tackle this problem. The new method simultaneously addresses two issues: (i) (Global association test) Are there any of the variants associated with the disease, and (ii) (Causal variant detection) Which variants, if any, are driving the association. The BRVD ensures the causal rare variants to be consistently identified in the small-n-large-P situation by imposing some appropriate prior distributions on the model and model specific parameters. The numerical results indicate that the BRVD is more powerful for testing the global association than the existing methods, such as the combined multivariate and collapsing test, weighted sum statistic test, RARECOVER, sequence kernel association test, and Bayesian risk index, and also more powerful for identification of causal rare variants than the Bayesian risk index method. The BRVD has also been successfully applied to the Early-Onset Myocardial Infarction (EOMI) Exome Sequence Data. It identified a few causal rare variants that have been verified in the literature.

  3. Bayesian detection of causal rare variants under posterior consistency.

    Directory of Open Access Journals (Sweden)

    Faming Liang

    Full Text Available Identification of causal rare variants that are associated with complex traits poses a central challenge on genome-wide association studies. However, most current research focuses only on testing the global association whether the rare variants in a given genomic region are collectively associated with the trait. Although some recent work, e.g., the Bayesian risk index method, have tried to address this problem, it is unclear whether the causal rare variants can be consistently identified by them in the small-n-large-P situation. We develop a new Bayesian method, the so-called Bayesian Rare Variant Detector (BRVD, to tackle this problem. The new method simultaneously addresses two issues: (i (Global association test Are there any of the variants associated with the disease, and (ii (Causal variant detection Which variants, if any, are driving the association. The BRVD ensures the causal rare variants to be consistently identified in the small-n-large-P situation by imposing some appropriate prior distributions on the model and model specific parameters. The numerical results indicate that the BRVD is more powerful for testing the global association than the existing methods, such as the combined multivariate and collapsing test, weighted sum statistic test, RARECOVER, sequence kernel association test, and Bayesian risk index, and also more powerful for identification of causal rare variants than the Bayesian risk index method. The BRVD has also been successfully applied to the Early-Onset Myocardial Infarction (EOMI Exome Sequence Data. It identified a few causal rare variants that have been verified in the literature.

  4. Bayesian detection of causal rare variants under posterior consistency.

    KAUST Repository

    Liang, Faming; Xiong, Momiao

    2013-01-01

    Identification of causal rare variants that are associated with complex traits poses a central challenge on genome-wide association studies. However, most current research focuses only on testing the global association whether the rare variants in a given genomic region are collectively associated with the trait. Although some recent work, e.g., the Bayesian risk index method, have tried to address this problem, it is unclear whether the causal rare variants can be consistently identified by them in the small-n-large-P situation. We develop a new Bayesian method, the so-called Bayesian Rare Variant Detector (BRVD), to tackle this problem. The new method simultaneously addresses two issues: (i) (Global association test) Are there any of the variants associated with the disease, and (ii) (Causal variant detection) Which variants, if any, are driving the association. The BRVD ensures the causal rare variants to be consistently identified in the small-n-large-P situation by imposing some appropriate prior distributions on the model and model specific parameters. The numerical results indicate that the BRVD is more powerful for testing the global association than the existing methods, such as the combined multivariate and collapsing test, weighted sum statistic test, RARECOVER, sequence kernel association test, and Bayesian risk index, and also more powerful for identification of causal rare variants than the Bayesian risk index method. The BRVD has also been successfully applied to the Early-Onset Myocardial Infarction (EOMI) Exome Sequence Data. It identified a few causal rare variants that have been verified in the literature.

  5. Application of evolutionary algorithm methods to polypeptide folding: comparison with experimental results for unsolvated Ac-(Ala-Gly-Gly)5-LysH+

    DEFF Research Database (Denmark)

    Damsbo, Martin; Kinnear, Brian S; Hartings, Matthew R

    2004-01-01

    We present an evolutionary method for finding the low-energy conformations of polypeptides. The application, called FOLDAWAY,is based on a generic framework and uses several evolutionary operators as well as local optimization to navigate the complex energy landscape of polypeptides. It maintains...... mobility measurements. It has a flat energy landscape where helical and globular conformations have similar energies. FOLDAWAY locates several large groups of structures not found in previous molecular dynamics simulations for this peptide, including compact globular conformations, which are probably...... two complementary representations of the structures and uses the CHARMM force field for evaluating the energies. The method is applied to unsolvated Met-enkephalin and Ac-(Ala-Gly-Gly)(5)-Lys(+)H(+). Unsolvated Ac-(Ala-Gly-Gly)(5)-Lys(+)H(+) has been the object of recent experimental studies using ion...

  6. Rapid measurement of 3J(H N-H alpha) and 3J(N-H beta) coupling constants in polypeptides.

    Science.gov (United States)

    Barnwal, Ravi Pratap; Rout, Ashok K; Chary, Kandala V R; Atreya, Hanudatta S

    2007-12-01

    We present two NMR experiments, (3,2)D HNHA and (3,2)D HNHB, for rapid and accurate measurement of 3J(H N-H alpha) and 3J(N-H beta) coupling constants in polypeptides based on the principle of G-matrix Fourier transform NMR spectroscopy and quantitative J-correlation. These experiments, which facilitate fast acquisition of three-dimensional data with high spectral/digital resolution and chemical shift dispersion, will provide renewed opportunities to utilize them for sequence specific resonance assignments, estimation/characterization of secondary structure with/without prior knowledge of resonance assignments, stereospecific assignment of prochiral groups and 3D structure determination, refinement and validation. Taken together, these experiments have a wide range of applications from structural genomics projects to studying structure and folding in polypeptides.

  7. Distinct localization of FMRFamide- and bovine pancreatic polypeptide-like material in the brain, retrocerebral complex and suboesophageal ganglion of the cockroach Periplaneta americana L

    DEFF Research Database (Denmark)

    Verhaert, P; Grimmelikhuijzen, C J; De Loof, A

    1985-01-01

    One bovine pancreatic polypeptide (BPP) antiserum and two FMRFamide antisera were applied in the peroxidase-antiperoxidase (PAP) immunohistochemical technique on a complete series of sections of brains, suboesophageal ganglia (SOG), corpora cardiaca (CC) and corpora allata of Periplaneta americana...... L. Double immunohistochemical staining demonstrated that the same perikarya and processes were stained by both the BPP and FMRFamide antisera. This was caused by cross-reaction of the BPP and FMRFamide antisera with common antigenic determinants as was shown by a number of solid-phase absorptions....... Application of a third FMRFamide antiserum, which was especially selected for its inability to react with bovine and avian pancreatic polypeptide, showed that more than half of the structures that were stained with the 'unspecific' BPP and FMRFamide antisera, contained material which was genuinely FMRFamide...

  8. Structure of conkunitzin-S1, a neurotoxin and Kunitz-fold disulfide variant from cone snail

    International Nuclear Information System (INIS)

    Dy, Catherine Y.; Buczek, Pawel; Imperial, Julita S.; Bulaj, Grzegorz; Horvath, Martin P.

    2006-01-01

    Most Kunitz proteins like BPTI and α-dendrotoxin are stabilized by three disulfide bonds. The crystal structure shows how subtle repacking of non-covalent interactions may compensate for disulfide bond loss in a naturally occurring two-disulfide variant, conkunitzin-S1, the first discovered member of a new conotoxin family. Cone snails (Conus) are predatory marine mollusks that immobilize prey with venom containing 50–200 neurotoxic polypeptides. Most of these polypeptides are small disulfide-rich conotoxins that can be classified into families according to their respective ion-channel targets and patterns of cysteine–cysteine disulfides. Conkunitzin-S1, a potassium-channel pore-blocking toxin isolated from C. striatus venom, is a member of a newly defined conotoxin family with sequence homology to Kunitz-fold proteins such as α-dendrotoxin and bovine pancreatic trypsin inhibitor (BPTI). While conkunitzin-S1 and α-dendrotoxin are 42% identical in amino-acid sequence, conkunitzin-S1 has only four of the six cysteines normally found in Kunitz proteins. Here, the crystal structure of conkunitzin-S1 is reported. Conkunitzin-S1 adopts the canonical 3 10 –β–β–α Kunitz fold complete with additional distinguishing structural features including two completely buried water molecules. The crystal structure, although completely consistent with previously reported NMR distance restraints, provides a greater degree of precision for atomic coordinates, especially for S atoms and buried solvent molecules. The region normally cross-linked by cysteines II and IV in other Kunitz proteins retains a network of hydrogen bonds and van der Waals interactions comparable to those found in α-dendrotoxin and BPTI. In conkunitzin-S1, glycine occupies the sequence position normally reserved for cysteine II and the special steric properties of glycine allow additional van der Waals contacts with the glutamine residue substituting for cysteine IV. Evolution has thus defrayed the

  9. Alternative Splicing of the Pituitary Adenylate Cyclase-Activating Polypeptide Receptor PAC1: Mechanisms of Fine Tuning of Brain Activity

    Directory of Open Access Journals (Sweden)

    Janna eBlechman

    2013-05-01

    Full Text Available Alternative splicing of the precursor mRNA encoding for the neuropeptide receptor PAC1/ADCYAP1R1 generates multiple protein products that exhibit pleiotropic activities. Recent studies in mammals and zebrafish have implicated some of these splice isoforms in control of both cellular and body homeostasis. Here, we review the regulation of PAC1 splice variants and their underlying signal transduction and physiological processes in the nervous system.

  10. Xylitol vs glucose: Effect on the rate of gastric emptying and motilin, insulin, and gastric inhibitory polypeptide release

    International Nuclear Information System (INIS)

    Salminen, E.K.; Salminen, S.J.; Porkka, L.; Kwasowski, P.; Marks, V.; Koivistoinen, P.E.

    1989-01-01

    The effect of xylitol and glucose on the rate of gastric emptying and intestinal transit and on motilin, gastric inhibitory polypeptide (GIP), and insulin release were studied in human volunteers. A single oral dose of 200 mL water containing 30 g glucose or 30 g xylitol, mixed with a 99m technetium-tin (99mTc-Sn) colloid, was used. Similar dosing without the label was used in motilin, GIP, and insulin studies. Xylitol decreased the rate of gastric emptying but concomitantly accelerated intestinal transit compared with glucose. The half-times for gastric emptying were 77.5 +/- 4.6 and 39.8 +/- 3.4 min after ingestion of xylitol and glucose solutions, respectively. Glucose suppressed motilin and stimulated GIP secretion; xylitol stimulated motilin secretion but had no effect on GIP, which is currently the main candidate for the role of enterogastrone. The accelerated intestinal transit and increase in plasma motilin observed after xylitol ingestion were thought to be causally related to the diarrhea and gastrointestinal discomfort produced by it

  11. The effects of isatin (indole-2, 3-dione on pituitary adenylate cyclase-activating polypeptide-induced hyperthermia in rats

    Directory of Open Access Journals (Sweden)

    Tóth Gábor

    2002-02-01

    Full Text Available Abstract Background Previous studies have demonstrated that centrally administered natriuretic peptides and pituitary adenylate cyclase-activating polypeptide-38 (PACAP-38 have hyperthermic properties. Isatin (indole-2, 3-dione is an endogenous indole that has previously been found to inhibit hyperthermic effects of natriuretic peptides. In this study the aim was to investigate the effects of isatin on thermoregulatory actions of PACAP-38, in rats. Results One μg intracerebroventricular (icv. injection of PACAP-38 had hyperthermic effect in male, Wistar rats, with an onset of the effect at 2 h and a decline by the 6th h after administration. Intraperitoneal (ip. injection of different doses of isatin (25-50 mg/kg significantly decreased the hyperthermic effect of 1 μg PACAP-38 (icv., whereas 12.5 mg/kg isatin (ip. had no inhibiting effect. Isatin alone did not modify the body temperature of the animals. Conclusion The mechanisms that participate in the mediation of the PACAP-38-induced hyperthermia may be modified by isatin. The capability of isatin to antagonize the hyperthermia induced by all members of the natriuretic peptide family and by PACAP-38 makes it unlikely to be acting directly on receptors for natriuretic peptides or on those for PACAP in these hyperthermic processes.

  12. Targeted Transgenic Overexpression of Mitochondrial Thymidine Kinase (TK2) Alters Mitochondrial DNA (mtDNA) and Mitochondrial Polypeptide Abundance

    Science.gov (United States)

    Hosseini, Seyed H.; Kohler, James J.; Haase, Chad P.; Tioleco, Nina; Stuart, Tami; Keebaugh, Erin; Ludaway, Tomika; Russ, Rodney; Green, Elgin; Long, Robert; Wang, Liya; Eriksson, Staffan; Lewis, William

    2007-01-01

    Mitochondrial toxicity limits nucleoside reverse transcriptase inhibitors (NRTIs) for acquired immune deficiency syndrome. NRTI triphosphates, the active moieties, inhibit human immunodeficiency virus reverse transcriptase and eukaryotic mitochondrial DNA polymerase pol-γ. NRTI phosphorylation seems to correlate with mitochondrial toxicity, but experimental evidence is lacking. Transgenic mice (TGs) with cardiac overexpression of thymidine kinase isoforms (mitochondrial TK2 and cytoplasmic TK1) were used to study NRTI mitochondrial toxicity. Echocardiography and nuclear magnetic resonance imaging defined cardiac performance and structure. TK gene copy and enzyme activity, mitochondrial (mt) DNA and polypeptide abundance, succinate dehydrogenase and cytochrome oxidase histochemistry, and electron microscopy correlated with transgenesis, mitochondrial structure, and biogenesis. Antiretroviral combinations simulated therapy. Untreated hTK1 or TK2 TGs exhibited normal left ventricle mass. In TK2 TGs, cardiac TK2 gene copy doubled, activity increased 300-fold, and mtDNA abundance doubled. Abundance of the 17-kd subunit of complex I, succinate dehydrogenase histochemical activity, and cristae density increased. NRTIs increased left ventricle mass 20% in TK2 TGs. TK activity increased 3 logs in hTK1 TGs, but no cardiac phenotype resulted. NRTIs abrogated functional effects of transgenically increased TK2 activity but had no effect on TK2 mtDNA abundance. Thus, NRTI mitochondrial phosphorylation by TK2 is integral to clinical NRTI mitochondrial toxicity. PMID:17322372

  13. Abnormal iron metabolism and oxidative stress in mice expressing a mutant form of the ferritin light polypeptide gene

    Science.gov (United States)

    Barbeito, Ana G.; Garringer, Holly J.; Baraibar, Martin A.; Gao, Xiaoying; Arredondo, Miguel; Núñez, Marco T.; Smith, Mark A.; Ghetti, Bernardino; Vidal, Ruben

    2009-01-01

    Insertional mutations in exon 4 of the ferritin light chain (FTL) gene are associated with hereditary ferritinopathy (HF) or neuroferritinopathy, an autosomal dominant neurodegenerative disease characterized by progressive impairment of motor and cognitive functions. To determine the pathogenic mechanisms by which mutations in FTL lead to neurodegeneration, we investigated iron metabolism and markers of oxidative stress in the brain of transgenic (Tg) mice that express the mutant human FTL498-499InsTC cDNA. Compared with wild-type mice, brain extracts from Tg (FTL-Tg) mice showed an increase in the cytoplasmic levels of both FTL and ferritin heavy chain polypeptides, a decrease in the protein and mRNA levels of transferrin receptor-1, and a significant increase in iron levels. Transgenic mice also showed the presence of markers for lipid peroxidation, protein carbonyls, and nitrone–protein adducts in the brain. However, gene expression analysis of iron management proteins in the liver of Tg mice indicates that the FTL-Tg mouse liver is iron deficient. Our data suggest that disruption of iron metabolism in the brain has a primary role in the process of neurodegeneration in HF and that the pathogenesis of HF is likely to result from a combination of reduction in iron storage function and enhanced toxicity associated with iron-induced ferritin aggregates in the brain. PMID:19519778

  14. High plasma levels of islet amyloid polypeptide in young with new-onset of type 1 diabetes mellitus.

    Directory of Open Access Journals (Sweden)

    Johan F Paulsson

    Full Text Available AIMS/HYPOTHESIS: Islet amyloid polypeptide (IAPP is a beta cell hormone secreted together with insulin upon glucose stimulation. IAPP participates in normal glucose regulation, but IAPP is also known for its ability to misfold and form islet amyloid. Amyloid fibrils form through smaller cell toxic intermediates and deposited amyloid disrupts normal islet architecture. Even though IAPP and amyloid formation are much discussed in type 2 diabetes, our aim was to study the significance of IAPP in type 1 diabetes. RESULTS: Plasma IAPP levels in children and adolescents with newly diagnosed type 1 diabetes (n = 224 were analysed and concentrations exceeding 100 pmol/L (127.2-888.7 pmol/L were found in 11% (25/224. The IAPP increase did not correlate with C-peptide levels. CONCLUSIONS/INTERPRETATION: Plasma levels of IAPP and insulin deviate in a subpopulation of young with newly-diagnosed type 1 diabetes. The determined elevated levels of IAPP might increase the risk for IAPP misfolding and formation of cell toxic amyloid in beta cells. This finding add IAPP-aggregation to the list over putative pathological factors causing type 1 diabetes.

  15. The effect of pancreatic polypeptide and peptide YY on pancreatic blood flow and pancreatic exocrine secretion in the anesthetized dog

    International Nuclear Information System (INIS)

    DeMar, A.R.; Lake, R.; Fink, A.S.

    1991-01-01

    Pancreatic polypeptide (PP) and peptide YY (PYY) are inhibitors of pancreatic exocrine secretion in vivo but not in vitro, which suggests intermediate mechanisms of action. To examine the role of pancreatic blood flow in these inhibitory effects, xenon-133 gas clearance was used to measure pancreatic blood flow while simultaneously measuring pancreatic exocrine secretion. PP or PYY (400 pmol/kg/h) was administered during the intermediate hour of a 3-h secretin (125 ng/kg/h)/cholecystokinin octapeptide (CCK-8) (50 ng/kg/h) infusion. Exocrine secretion and pancreatic blood flow during the PP or PYY hours were compared with that observed in the first and third hours of the secretin/CCK-8 infusion. PP and PYY significantly inhibited secretin/CCK-8-induced pancreatic exocrine secretion. In addition, PYY (but not PP) significantly reduced pancreatic blood flow during secretin/CCK-8 stimulation. Nevertheless, there was no correlation between pancreatic blood flow and bicarbonate or protein outputs. It is concluded that changes in pancreatic blood flow do not mediate the inhibitory effects of PP or PYY on the exocrine pancreas

  16. Sequence-Dependent Self-Assembly and Structural Diversity of Islet Amyloid Polypeptide-Derived β-Sheet Fibrils

    International Nuclear Information System (INIS)

    Wang, Shih-Ting; Lin, Yiyang; Spencer, Ryan K.; Thomas, Michael R.; Nguyen, Andy I.

    2017-01-01

    Determining the structural origins of amyloid fibrillation is essential for understanding both the pathology of amyloidosis and the rational design of inhibitors to prevent or reverse amyloid formation. In this work, the decisive roles of peptide structures on amyloid self-assembly and morphological diversity were investigated by the design of eight amyloidogenic peptides derived from islet amyloid polypeptide. Among the segments, two distinct morphologies were highlighted in the form of twisted and planar (untwisted) ribbons with varied diameters, thicknesses, and lengths. In particular, transformation of amyloid fibrils from twisted ribbons into untwisted structures was triggered by substitution of the C-terminal serine with threonine, where the side chain methyl group was responsible for the distinct morphological change. This effect was confirmed following serine substitution with alanine and valine and was ascribed to the restriction of intersheet torsional strain through the increased hydrophobic interactions and hydrogen bonding. We also studied the variation of fibril morphology (i.e., association and helicity) and peptide aggregation propensity by increasing the hydrophobicity of the peptide side group, capping the N-terminus, and extending sequence length. Lastly, we anticipate that our insights into sequence-dependent fibrillation and morphological diversity will shed light on the structural interpretation of amyloidogenesis and development of structure-specific imaging agents and aggregation inhibitors.

  17. Rapid and simple purification of elastin-like polypeptides directly from whole cells and cell lysates by organic solvent extraction.

    Science.gov (United States)

    VerHeul, Ross; Sweet, Craig; Thompson, David H

    2018-03-26

    Elastin-like polypeptides (ELP) are a well-known class of proteins that are being increasingly utilized in a variety of biomedical applications, due to their beneficial physicochemical properties. A unifying feature of ELP is their demonstration of a sequence tunable inverse transition temperature (Tt) that enables purification using a simple, straightforward process called inverse transition cycling (ITC). Despite the utility of ITC, the process is inherently limited to ELP with an experimentally accessible Tt. Since the underlying basis for the ELP Tt is related to its high overall hydrophobicity, we anticipated that ELP would be excellent candidates for purification by organic extraction. We report the first method for rapidly purifying ELP directly from whole E. coli cells or clarified lysates using pure organic solvents and solvent mixtures, followed by aqueous back extraction. Our results show that small ELP and a large ELP-fusion protein can be isolated in high yield from whole cells or cell lysates with greater than 95% purity in less than 30 min and with very low levels of LPS and DNA contamination.

  18. Mast cell chymase reduces the toxicity of Gila monster venom, scorpion venom, and vasoactive intestinal polypeptide in mice

    Science.gov (United States)

    Akahoshi, Mitsuteru; Song, Chang Ho; Piliponsky, Adrian M.; Metz, Martin; Guzzetta, Andrew; Åbrink, Magnus; Schlenner, Susan M.; Feyerabend, Thorsten B.; Rodewald, Hans-Reimer; Pejler, Gunnar; Tsai, Mindy; Galli, Stephen J.

    2011-01-01

    Mast cell degranulation is important in the pathogenesis of anaphylaxis and allergic disorders. Many animal venoms contain components that can induce mast cell degranulation, and this has been thought to contribute to the pathology and mortality caused by envenomation. However, we recently reported evidence that mast cells can enhance the resistance of mice to the venoms of certain snakes and that mouse mast cell–derived carboxypeptidase A3 (CPA3) can contribute to this effect. Here, we investigated whether mast cells can enhance resistance to the venom of the Gila monster, a toxic component of that venom (helodermin), and the structurally similar mammalian peptide, vasoactive intestinal polypeptide (VIP). Using 2 types of mast cell–deficient mice, as well as mice selectively lacking CPA3 activity or the chymase mouse mast cell protease-4 (MCPT4), we found that mast cells and MCPT4, which can degrade helodermin, can enhance host resistance to the toxicity of Gila monster venom. Mast cells and MCPT4 also can limit the toxicity associated with high concentrations of VIP and can reduce the morbidity and mortality induced by venoms from 2 species of scorpions. Our findings support the notion that mast cells can enhance innate defense by degradation of diverse animal toxins and that release of MCPT4, in addition to CPA3, can contribute to this mast cell function. PMID:21926462

  19. Multi-functional roles for the polypeptide transport associated domains of Toc75 in chloroplast protein import

    Science.gov (United States)

    Paila, Yamuna D; Richardson, Lynn GL; Inoue, Hitoshi; Parks, Elizabeth S; McMahon, James; Inoue, Kentaro; Schnell, Danny J

    2016-01-01

    Toc75 plays a central role in chloroplast biogenesis in plants as the membrane channel of the protein import translocon at the outer envelope of chloroplasts (TOC). Toc75 is a member of the Omp85 family of bacterial and organellar membrane insertases, characterized by N-terminal POTRA (polypeptide-transport associated) domains and C-terminal membrane-integrated β-barrels. We demonstrate that the Toc75 POTRA domains are essential for protein import and contribute to interactions with TOC receptors, thereby coupling preprotein recognition at the chloroplast surface with membrane translocation. The POTRA domains also interact with preproteins and mediate the recruitment of molecular chaperones in the intermembrane space to facilitate membrane transport. Our studies are consistent with the multi-functional roles of POTRA domains observed in other Omp85 family members and demonstrate that the domains of Toc75 have evolved unique properties specific to the acquisition of protein import during endosymbiotic evolution of the TOC system in plastids. DOI: http://dx.doi.org/10.7554/eLife.12631.001 PMID:26999824

  20. Comparison of Fasting Human Pancreatic Polypeptide Levels Among Patients With Pancreatic Ductal Adenocarcinoma, Chronic Pancreatitis, and Type 2 Diabetes Mellitus.

    Science.gov (United States)

    Nagpal, Sajan Jiv Singh; Bamlet, William R; Kudva, Yogish C; Chari, Suresh T

    2018-05-17

    Human pancreatic polypeptide (HPP) is a hormone secreted by the ventral pancreas. While postprandial HPP levels have been studied in chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDAC), there are limited data on fasting HPP in these diseases. Fasting serum HPP was measured in the following groups of patients: CP with diabetes mellitus (DM) (n = 16), CP without DM (n = 34), PDAC with new-onset DM (n = 50), PDAC without DM (n = 49), new-onset type 2 DM (n = 50), and controls without DM (n = 49). Sixty-six had type 3c DM (CP with DM, n = 16; PDAC with new-onset DM, n = 50). Median fasting HPP levels (in picograms per milliliter) were similar among all groups. Median (interquartile range) HPP levels in new-onset type 2 DM (n = 50; 288.3 [80.1-1072.1]) were similar to those in type 3c DM (n = 66; 242.3 [64.9-890.9]) (P = 0.71). In PDAC (n = 99), HPP values were similar in pancreatic head (n = 75) versus body/tail (n = 24) tumors (245.3 [64.3-1091.3] vs 334.7 [136.1-841.5]; P = 0.95), regardless of DM. Fasting HPP levels are similar in CP, PDAC, and controls regardless of glycemic status.