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Sample records for c-type lectin domain

  1. Function of a novel C-type lectin with two CRD domains from Macrobrachium rosenbergii in innate immunity.

    Science.gov (United States)

    Huang, Xin; Huang, Ying; Shi, Yan-Ru; Ren, Qian; Wang, Wen

    2015-03-01

    C-type lectins play crucial roles in innate immunity. In the present study, a novel C-type lectin gene, designated as MrCTL, was identified from Macrobrachium rosenbergii. MrCTL contains 2 carbohydrate-recognition domains (CRDs), namely MrCRD1 and MrCRD2. The MrCRD1 contains a QEP motif and MrCRD2 contains a motif of EPD. MrCTL was mainly expressed in the hepatopancreas. The expression level of MrCTL in hepatopancreas was significantly upregulated after a challenge with Vibrio parahaemolyticus or White spot syndrome virus (WSSV). The recombinant MrCTL, MrCRD1 and MrCRD2 have an ability to agglutinate both Gram-negative (V. parahaemolyticus) and Gram-positive bacteria (Staphylococcus aureus) in a calcium dependent manner. The recombinant MrCTL, MrCRD1 and MrCRD2 bind directly to all tested microorganisms. All these results suggested that MrCTL may have important roles in immune defense against invading pathogens in prawns.

  2. Structure of the C-type lectin carbohydrate recognition domain of human tetranectin

    DEFF Research Database (Denmark)

    Kastrup, J S; Nielsen, B B; Rasmussen, H

    1998-01-01

    of certain human carcinomas, whereas none or little is present in the corresponding normal tissue. The crystal structure of full-length trimeric TN (2.8 A resolution) has recently been published [Nielsen et al. (1997). FEBS Lett. 412, 388-396]. The crystal structure of the carbohydrate recognition domain...

  3. The Structure of the Poxvirus A33 Protein Reveals a Dimer of Unique C-Type Lectin-Like Domains

    Energy Technology Data Exchange (ETDEWEB)

    Su, Hua-Poo; Singh, Kavita; Gittis, Apostolos G.; Garboczi, David N. (NIH)

    2010-11-03

    The current vaccine against smallpox is an infectious form of vaccinia virus that has significant side effects. Alternative vaccine approaches using recombinant viral proteins are being developed. A target of subunit vaccine strategies is the poxvirus protein A33, a conserved protein in the Chordopoxvirinae subfamily of Poxviridae that is expressed on the outer viral envelope. Here we have determined the structure of the A33 ectodomain of vaccinia virus. The structure revealed C-type lectin-like domains (CTLDs) that occur as dimers in A33 crystals with five different crystal lattices. Comparison of the A33 dimer models shows that the A33 monomers have a degree of flexibility in position within the dimer. Structural comparisons show that the A33 monomer is a close match to the Link module class of CTLDs but that the A33 dimer is most similar to the natural killer (NK)-cell receptor class of CTLDs. Structural data on Link modules and NK-cell receptor-ligand complexes suggest a surface of A33 that could interact with viral or host ligands. The dimer interface is well conserved in all known A33 sequences, indicating an important role for the A33 dimer. The structure indicates how previously described A33 mutations disrupt protein folding and locates the positions of N-linked glycosylations and the epitope of a protective antibody.

  4. C-type lectin-like domain and fibronectin-like type II domain of phospholipase A(2) receptor 1 modulate binding and migratory responses to collagen.

    Science.gov (United States)

    Takahashi, Soichiro; Watanabe, Kazuhiro; Watanabe, Yosuke; Fujioka, Daisuke; Nakamura, Takamitsu; Nakamura, Kazuto; Obata, Jun-ei; Kugiyama, Kiyotaka

    2015-03-24

    Phospholipase A2 receptor 1 (PLA2R) mediates collagen-dependent migration. The mechanisms by which PLA2R interacts with collagen remain unclear. We produced HEK293 cells expressing full-length wild-type PLA2R or a truncated PLA2R that lacks fibronectin-like type II (FNII) domains or several regions of C-type lectin-like domain (CTLD). We show that the CTLD1-2 as well as the FNII domain of PLA2R are responsible for binding to collagen and for collagen-dependent migration. Thus, multiple regions and domains of the extracellular portion of PLA2R participate in the responses to collagen. These data suggest a potentially new mechanism for PLA2R-mediated biological response beyond that of a receptor for secretory PLA2.

  5. The plasminogen binding site of the C-type lectin tetranectin is located in the carbohydrate recognition domain, and binding is sensitive to both calcium and lysine

    DEFF Research Database (Denmark)

    Graversen, Jonas Heilskov; Lorentsen, R H; Jacobsen, C

    1998-01-01

    Tetranectin, a homotrimeric protein belonging to the family of C-type lectins and structurally highly related to corresponding regions of the mannose-binding proteins, is known specifically to bind the plasminogen kringle 4 protein domain, an interaction sensitive to lysine. Surface plasmon...... resonance and isothermal calorimetry binding analyses using single-residue and deletion mutant tetranectin derivatives produced in Escherichia coli showed that the kringle 4 binding site resides in the carbohydrate recognition domain and includes residues of the putative carbohydrate binding site...

  6. C-type lectins%C型凝集素

    Institute of Scientific and Technical Information of China (English)

    谢建辉; 顾建新

    2011-01-01

    C型凝集素(C-type lectin)代表一个识别碳水化合物配体依赖于钙离子(Ca2+)参与的糖原结合蛋白家族,含有一个或多个一级结构和二级结构同源的碳水化合物识别结构域.随着研究的深入,越来越多的C型凝集素能够识别体内的非糖类的配体,包括蛋白质和脂类等.这些C型凝集素在维持机体稳态、免疫防御以及免疫监视等重要生理病理过程中发挥着重要作用.就C型凝集素的结构、分类和在免疫系统中的功能作一介绍.%C-type lectins are Ca2+-dependent glycan-binding proteins and share primary and secondary structural homology in their carbohydrate-recognition domains (CRDs). However, many members of this family are recently identified not to bind carbohydrates and have evolved to recognize non-sugar ligands such as proteins and lipids. The large family of C-type lectins has an important role in the physiological functions and pathological processes including immune homeostasis, immune defenses, and immune surveillance and so on. In this short review, we summarize the structure of C-type lectin domain, the classification of C-type lectins and their role in the immune system.

  7. Structure of the plasminogen kringle 4 binding calcium-free form of the C-type lectin-like domain of tetranectin

    DEFF Research Database (Denmark)

    Nielbo, Steen; Thomsen, Jens K; Graversen, Jonas Heilskov;

    2004-01-01

    Tetranectin is a homotrimeric protein containing a C-type lectin-like domain. This domain (TN3) can bind calcium, but in the absence of calcium, the domain binds a number of kringle-type protein ligands. Two of the calcium-coordinating residues are also critical for binding plasminogen kringle 4 (K......4). The structure of the calcium free-form of TN3 (apoTN3) has been determined by NMR. Compared to the structure of the calcium-bound form of TN3 (holoTN3), the core region of secondary structural elements is conserved, while large displacements occur in the loops involved in calcium or K4 binding....... A conserved proline, which was found to be in the cis conformation in holoTN3, is in apoTN3 predominantly in the trans conformation. Backbone dynamics indicate that, in apoTN3 especially, two of the three calcium-binding loops and two of the three K4-binding residues exhibit increased flexibility, whereas...

  8. The C-type lectin-like domain containing proteins Clec-39 and Clec-49 are crucial for Caenorhabditis elegans immunity against Serratia marcescens infection.

    Science.gov (United States)

    Miltsch, S M; Seeberger, P H; Lepenies, B

    2014-07-01

    Caenorhabditis elegans exhibits protective immunity against a variety of fungal and bacterial pathogens. Since C. elegans lacks an adaptive immune system, pathogen recognition is mediated entirely by innate immunity. To date, little is known about the involvement of pattern recognition receptors (PRRs) in pathogen sensing as part of the C. elegans immunity. C-type lectin-like domain (CTLD) containing proteins represent a superfamily of PRRs. A large number of genes encoding for CTLD proteins are present in the C. elegans genome, however the role of CTLD proteins in bacterial recognition and antibacterial immunity has not yet been determined. In this study, we investigated the function of selected C. elegans CTLD proteins during infection with the Gram-negative bacterium Serratia marcescens. Wild-type and CTLD gene-deficient C. elegans strains were compared in their susceptibility to S. marcescens infection. Interestingly, survival and egg laying were significantly reduced in strains deficient for clec-39 and clec-49 indicating a role for both CTLD proteins in C. elegans immune defense against bacteria as evidenced by using S. marcescens infection. Binding studies with recombinantly expressed Clec-39-Fc and Clec-49-Fc fusion proteins revealed that both CTLD proteins recognized live bacteria in a Ca(2+)-independent manner. This study provides insight into the role of CTLD proteins in C. elegans immunity and demonstrates their function during bacterial infection.

  9. Molecular cloning of a new secreted sulfated mucin-like protein with a C-type lectin domain that is expressed in lymphoblastic cells.

    Science.gov (United States)

    Bannwarth, S; Giordanengo, V; Lesimple, J; Lefebvre, J C

    1998-01-23

    We have previously demonstrated hyposialylation of the two major CD45 and leukosialin (CD43) molecules at the surface of latently human immunodeficiency virus type 1-infected CEM T cells (CEMLAI/NP), (Lefebvre, J. C., Giordanengo, V., Doglio, A., Cagnon, L., Breittmayer, J. P., Peyron, J. F., and Lesimple, J. (1994) Virology 199, 265-274; Lefebvre, J. C., Giordanengo, V., Limouse, M., Doglio, A., Cucchiarini, M., Monpoux, F., Mariani, R., and Peyron, J. F. (1994) J. Exp. Med. 180, 1609-1617). Searching to clarify mechanism(s) of hyposialylation, we observed two sulfated secreted glycoproteins (molecular mass approximately 47 and approximately 40 kDa) (P47 and P40), which were differentially sulfated and/or differentially secreted in the culture supernatants of CEMLAI/NP cells when compared with parental CEM cells. A hybridoma clone (7H1) resulting from the fusion between CEMLAI/NP and human embryonic fibroblasts MRC5 cells produced very large amounts of P47 that was purified using Jacalin lectin (specific for O-glycans) and microsequenced. Cloning of P47 was achieved using a CEMLAI/NP cDNA library screened with a degenerate oligonucleotide probe based on its NH2-terminal amino acid sequence. A single open reading frame encoding a protein of 323 amino acids was deduced from the longest isolated recombinant (1.4 kilobase). P47 is a secreted sulfated protein. It carries an NH2-terminal RGD (Arg-Gly-Asp) triplet, a striking alpha-helical leucine zipper composed of six heptads, and a C-terminal C-type lectin domain. The NH2-terminal portion is rich in glutamic acids with a predicted pI of 3.9. In addition, a hinge region with numerous condensed potential sites for O-glycan side chains, which are also the most likely sulfation sites, is located between the RGD and leucine zipper domains. Transcripts were detected in lymphoid tissues (notably bone marrow) and abundantly in T and B lymphoblastoid but very faintly in monocytoid cell lines.

  10. Structure of a glycomimetic ligand in the carbohydrate recognition domain of C-type lectin DC-SIGN. Structural requirements for selectivity and ligand design.

    Science.gov (United States)

    Thépaut, Michel; Guzzi, Cinzia; Sutkeviciute, Ieva; Sattin, Sara; Ribeiro-Viana, Renato; Varga, Norbert; Chabrol, Eric; Rojo, Javier; Bernardi, Anna; Angulo, Jesus; Nieto, Pedro M; Fieschi, Franck

    2013-02-20

    In genital mucosa, different fates are described for HIV according to the subtype of dendritic cells (DCs) involved in its recognition. This notably depends on the C-type lectin receptor, langerin or DC-SIGN, involved in gp120 interaction. Langerin blocks HIV transmission by its internalization in specific organelles of Langerhans cells. On the contrary, DC-SIGN enhances HIV trans-infection of T lymphocytes. Thus, approaches aiming to inhibit DC-SIGN, without blocking langerin, represent attractive anti-HIV strategies. We previously demonstrated that dendrons bearing multiple copies of glycomimetic compounds were able to block DC-SIGN-dependent HIV infection in cervical explant models. Optimization of such ligand requires detailed characterization of its binding mode. In the present work, we determined the first high-resolution structure of a glycomimetic/DC-SIGN complex by X-ray crystallography. This glycomimetic, pseudo-1,2-mannobioside, shares shape and conformational properties with Manα1-2Man, its natural counterpart. However, it uses the binding epitope previously described for Lewis X, a ligand specific for DC-SIGN among the C-type lectin family. Thus, selectivity gain for DC-SIGN versus langerin is observed with pseudo-1,2-mannobioside as shown by surface plasmon resonance analysis. In parallel, ligand binding was also analyzed by TR-NOESY and STD NMR experiments, combined with the CORCEMA-ST protocol. These studies demonstrate that the complex, defined by X-ray crystallography, represents the unique binding mode of this ligand as opposed to the several binding orientations described for the natural ligand. This exclusive binding mode and its selective interaction properties position this glycomimetic as a good lead compound for rational improvement based on a structurally driven approach.

  11. Intestinally secreted C-type lectin Reg3b attenuates salmonellosis but not listeriosis in mice

    NARCIS (Netherlands)

    Ampting, van M.T.J.; Loonen, L.M.P.; Schonewille, A.J.; Konings, I.; Vink, C.; Iovanna, J.; Chamaillard, M.; Dekker, J.; Meer, van der R.; Wells, J.; Bovee-Oudenhoven, I.M.J.

    2012-01-01

    The Reg3 protein family, including the human member designated pancreatitis-associated protein (PAP), consists of secreted proteins that contain a C-type lectin domain involved in carbohydrate binding. They are expressed by intestinal epithelial cells. Colonization of germ-free mice and intestinal i

  12. DMPD: C-type lectin receptors in antifungal immunity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18160296 C-type lectin receptors in antifungal immunity. Willment JA, Brown GD. Tre...nds Microbiol. 2008 Jan;16(1):27-32. Epub 2007 Dec 21. (.png) (.svg) (.html) (.csml) Show C-type lectin receptors in anti...fungal immunity. PubmedID 18160296 Title C-type lectin receptors in antifungal immunity. Author

  13. Crotacetin, a novel snake venom C-type lectin, is homolog of convulxin

    Directory of Open Access Journals (Sweden)

    G. Rádis-Baptista

    2005-12-01

    Full Text Available Snake venom (sv C-type lectins encompass a group of hemorrhagic toxins, which are able to interfere with hemostasis. They share significant similarity in their primary structures with C-type lectins of other animals, and also present a conserved carbohydrate recognition domain (CRD. A very well studied sv C-type lectin is the heterodimeric toxin, convulxin (CVX, from the venoms of South American rattlesnakes, Crotalus durissus terrificus and C. d. cascavella. It consists of two subunits, alfa (CVXalpha , 13.9 kDa and beta (CVXbeta , 12.6 kDa, joined by inter and intra-chain disulfide bounds, and is arranged in a tetrameric alpha4beta4 conformation. Convulxin is able to activate platelet and induce their aggregation by acting via p62/GPVI collagen receptor. Several cDNA precursors, homolog of CVX subunits, were cloned by PCR homology screening. As determined by computational analysis, one of them, named crotacetin beta subunit, was predicted as a polypeptide with a tridimensional conformation very similar to other subunits of convulxin-like snake toxins. Crotacetin was purified from C. durissus venoms by gel permeation and reverse phase high performance liquid chromatography. The heterodimeric crotacetin is expressed in the venoms of several C. durissus subspecies, but it is prevalent in the venom of C. durissus cascavella. As inferred from homology modeling, crotacetin induces platelet aggregation but noticeably exhibits antimicrobial activity against Gram-positive and Gram-negative bacteria.

  14. A novel C-type lectin from the shrimp Litopenaeus vannamei possesses anti-white spot syndrome virus activity.

    Science.gov (United States)

    Zhao, Zhi-Ying; Yin, Zhi-Xin; Xu, Xiao-Peng; Weng, Shao-Ping; Rao, Xia-Yu; Dai, Zong-Xian; Luo, Yong-Wen; Yang, Gan; Li, Zong-Sheng; Guan, Hao-Ji; Li, Se-Dong; Chan, Siu-Ming; Yu, Xiao-Qiang; He, Jian-Guo

    2009-01-01

    C-type lectins play key roles in pathogen recognition, innate immunity, and cell-cell interactions. Here, we report a new C-type lectin (C-type lectin 1) from the shrimp Litopenaeus vannamei (LvCTL1), which has activity against the white spot syndrome virus (WSSV). LvCTL1 is a 156-residue polypeptide containing a C-type carbohydrate recognition domain with an EPN (Glu(99)-Pro(100)-Asn(101)) motif that has a predicted ligand binding specificity for mannose. Reverse transcription-PCR analysis revealed that LvCTL1 mRNA was specifically expressed in the hepatopancreas of L. vannamei. Recombinant LvCTL1 (rLvCTL1) had hemagglutinating activity and ligand binding specificity for mannose and glucose. rLvCTL1 also had a strong affinity for WSSV and interacted with several envelope proteins of WSSV. Furthermore, we showed that the binding of rLvCTL1 to WSSV could protect shrimps from viral infection and prolong the survival of shrimps against WSSV infection. Our results suggest that LvCTL1 is a mannose-binding C-type lectin that binds to envelope proteins of WSSV to exert its antiviral activity. To our knowledge, this is the first report of a shrimp C-type lectin that has direct anti-WSSV activity.

  15. C-type lectins do not act as functional receptors for filovirus entry into cells

    Energy Technology Data Exchange (ETDEWEB)

    Matsuno, Keita; Nakayama, Eri; Noyori, Osamu [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo (Japan); Marzi, Andrea; Ebihara, Hideki [Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, MT (United States); Irimura, Tatsuro [Graduate School of Pharmaceutical Science, University of Tokyo, Tokyo (Japan); Feldmann, Heinz [Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, MT (United States); Takada, Ayato, E-mail: atakada@czc.hokudai.ac.jp [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo (Japan)

    2010-12-03

    Research highlights: {yields} Filovirus glycoprotein (GP) having a deficient receptor binding region were generated. {yields} Mutant GPs mediated virus entry less efficiently than wild-type GP. {yields} Mutant GPs bound to C-type lectins but not mediated entire steps of cellular entry. {yields} C-type lectins do not independently mediate filovirus entry into cells. {yields} Other molecule(s) are required for C-type lectin-mediated entry of filoviruses. -- Abstract: Cellular C-type lectins have been reported to facilitate filovirus infection by binding to glycans on filovirus glycoprotein (GP). However, it is not clearly known whether interaction between C-type lectins and GP mediates all the steps of virus entry (i.e., attachment, internalization, and membrane fusion). In this study, we generated vesicular stomatitis viruses pseudotyped with mutant GPs that have impaired structures of the putative receptor binding regions and thus reduced ability to infect the monkey kidney cells that are routinely used for virus propagation. We found that infectivities of viruses with the mutant GPs dropped in C-type lectin-expressing cells, parallel with those in the monkey kidney cells, whereas binding activities of these GPs to the C-type lectins were not correlated with the reduced infectivities. These results suggest that C-type lectin-mediated entry of filoviruses requires other cellular molecule(s) that may be involved in virion internalization or membrane fusion.

  16. C-type Lectin Receptors for Tumor Eradication: Future Directions

    Energy Technology Data Exchange (ETDEWEB)

    Streng-Ouwehand, Ingeborg; Unger, Wendy W. J.; Kooyk, Yvette van, E-mail: y.vankooyk@vumc.nl [Department of Molecular Cell Biology and Immunology, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam (Netherlands)

    2011-08-08

    Dendritic cells are key regulators in directing immune responses and therefore are under extensive research for the induction of anti-tumor responses. DCs express a large array of receptors by which they scan their surroundings for recognition and uptake of pathogens. One of the receptor-families is the C-type lectins (CLR), which bind carbohydrate structures and internalize antigens upon recognition. Intracellular routing of antigen through CLR enhances loading and presentation of antigen through MHC class I and II, inducing antigen-specific CD4{sup +} and CD8{sup +} T-cell proliferation and skewing T-helper cells. These characteristics make CLRs very interesting targets for DC-based immunotherapy. Profound research has been done on targeting specific tumor antigens to CLR using either antibodies or the natural ligands such as glycan structures. In this review we will focus on the current data showing the potency of CLR-targeting and discuss improvements that can be achieved to enhance anti-tumor activity in the near future.

  17. Targeting C-type Lectin Receptors for Cancer Immunity

    Directory of Open Access Journals (Sweden)

    Huimin eYan

    2015-08-01

    Full Text Available C-type lectin receptors (CLRs are a large family of soluble and trans-membrane pattern recognition receptors that are widely and primarily expressed on myeloid cells. CLRs are important for cell-cell communication and host defense against pathogens through the recognition of specific carbohydrate structures. Similar to a family of Toll-like receptors (TLRs, CLRs signaling are involved in the various steps for initiation of innate immune responses and promote secretion of soluble factors such as cytokines and interferons, Moreover, CLRs contribute to endocytosis and antigen-presentation, thereby fine-tune adaptive immune responses. In addition, there may also be a direct activation of acquired immunity. On the other hand, glycans, such as mannose structures, Lewis-type antigens or GalNAc are components of tumor antigens and ligate CLRs, leading to immunoregulation. Therefore agonists or antagonists of CLRs signaling are potential therapeutic reagents for cancer immunotherapy. We aim to overview the current knowledge of CLRs signaling and the application of their ligands on tumor-associating immune response.

  18. Molecular cloning and characterization of a C-type lectin in yellow catfish Tachysurus fulvidraco.

    Science.gov (United States)

    Ke, F; Zhang, H B; Wang, Y; Hou, L F; Dong, H J; Wang, Z F; Pan, G W; Cao, X Y

    2016-09-01

    This study represents the first report of a C-type lectin (ctl) in yellow catfish Tachysurus fulvidraco. The complete sequence of ctl complementary (c)DNA consisted of 685 nucleotides. The open reading frame potentially encoded a protein of 177 amino acids with a calculated molecular mass of c.y 20.204 kDa. The deduced amino-acid sequence contained a signal peptide and a single carbohydrate recognition domain with four cysteine residues and GlnProAsp (QPD) and TrpAsnAsp (WND) motifs. Ctl showed the highest identity (56.0%) to the predicted lactose binding lectin from channel catfish Ictalurus punctatus. Quantitative real-time (qrt)-PCR analysis showed that ctl messenger (m)RNA was constitutively expressed in all examined tissues in normal fish, with high expression in trunk kidney and head kidney, which was increased following Aeromonas hydrophila challenge in a duration-dependent manner. Purified recombinant Ctl (rCtl) from Escherichia coli BL21 was able to bind and agglutinate Gram-positive and Gram-negative bacteria in a calcium-dependent manner. These results suggested that Ctl might be a C-type lectin of T. fulvidraco involved in innate immune responses as receptors (PRR).

  19. Molecular characterization and expression analysis of a novel dual-CRD C-type lectin in kuruma shrimp (Marsupenaeus japonicus)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Man; MAO Yong; WANG Jun; FENG Wenrong; SONG Xiaohong; SU Yongquan

    2015-01-01

    C-type lectins are among the most significant pattern recognition receptors (PRRs) found in invertebrate. They are a class of carbohydrate-binding proteins that can recognize specific sugar moieties on the surface of pathogens. In the present study, a novel C-type lecitn (termed MjLectin) from kuruma shrimp Marsupenaeus japonicus was identified. The full-length cDNA of MjLectin was 1 245 bp with a 1 011 bp open reading frame (ORF) that encoded a polypeptide of 336 amino acid residues. MjLectin consisted of two tandemly arrayed carbohydrate-recognition domains (CRDs), unlike other reported M. japonicus C-type lectins with only one CRD. It showed a high similarity to other shrimp dual-CRD lectins. Among the Ca2+-binding Site 2, the tripeptide motif dictating the carbohydrate binding specificity was exhibited as a rare mutant LPN (Leu134-Pro135-Asn136) in CRD1 and a traditional EPN (Glu299-Pro300-Asn301) in CRD2, respectively. MjLectin showed a specific expression pattern in both tissue and cellular levels, for its mRNA transcript was mainly expressed in the F-cells of the hepatopancreas. After white spot syndrome virus (WSSV) challenge (3.6×108 virions/μL), the expression of MjLectin in the hepatopancreas was up-regulated significantly at 48 h (P<0.01) compared with the control group. These results suggested that MjLectin might be involved in the innate immune defense against WSSV infection.

  20. Macrophage galactose-type C-type lectin receptor for DC targeting of antitumor glycopeptide vaccines

    DEFF Research Database (Denmark)

    Nuti, M; Zizzari, I; Napoletano, C;

    2011-01-01

    e13528 Background: Dendritic cells (DCs) are the most potent antigen presenting cells and are employed in cancer vaccination. Several receptors are being studied in order to identif strategies to increase DCs activating capacity. The C-type lectin macrophage galactose type C-type lectin (MGL...... of IFNg and IL-2 secretion by both CD8 and CD4 T cells. CONCLUSIONS: These results demonstrate that MGL engagement profoundly affects DC plasticity inducing and directing a Th1 immune response. Moreover, MGL receptor expressed on human DC can be targeted by glycopeptide based vaccines with adjuvant...

  1. Purification and biological effects of a C-type lectin isolated from Bothrops moojeni

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    PSF Barbosa

    2010-01-01

    Full Text Available Snake venom proteins from the C-type lectin family have very distinct biological activities despite their highly conserved primary structure, which is homologous to the carbohydrate recognition region of true C-type lectins. We purified a lectin-like protein (BmLec from Bothrops moojeni venom and investigated its effect on platelet aggregation, insulin secretion, antibacterial activity, and isolated kidney cells. The BmLec was purified using two chromatographic steps: affinity chromatography and reverse phase high performance liquid chromatography (HPLC. BmLec showed a dose-dependent platelet aggregation and significantly decreased the bacterial growth rate in approximately 15%. During scanning electron microscopy, the profile of Xanthomonas axonopodis pv. passiflorae treated with lectin disclosed a high vesiculation and membrane rupture. BmLec induced a strong and significant increase in insulin secretion at 2.8 and 16.7 mM glucose concentrations, and this effect was seen in the presence of EGTA in both experiments. BmLec (10 µg/mL increased the perfusion pressure, renal vascular resistance and urinary flow. The glomerular filtration rate and percentages of sodium, potassium and chloride tubular transport were reduced at 60 minutes of perfusion. Renal alterations caused by BmLec were completely inhibited by indomethacin in all evaluated parameters. In conclusion, the C-type lectin isolated from Bothrops moojeni affected platelet aggregation, insulin secretion, antibacterial activity and isolated kidney function.

  2. Targeting of macrophage galactose-type C-type lectin (MGL) induces DC signaling and activation

    DEFF Research Database (Denmark)

    Napoletano, Chiara; Zizzari, Ilaria G; Rughetti, Aurelia;

    2012-01-01

    Dendritic cells (DCs) sense the microenvironment through several types of receptors recognizing pathogen-associated molecular patterns. In particular, C-type lectins, expressed by distinct subsets of DCs, recognize and internalize specific carbohydrate antigen in a Ca(2+) -dependent manner. Targe...

  3. Levels of complexity in pathogen recognition by C-type lectins.

    NARCIS (Netherlands)

    Cambi, A.; Figdor, C.G.

    2005-01-01

    In pathogen recognition by C-type lectins, several levels of complexity can be distinguished; these might modulate the immune response in different ways. Firstly, the pathogen-associated molecular pattern repertoire expressed at the microbial surface determines the interactions with specific recepto

  4. Transmission-blocking antibodies against mosquito C-type lectins for dengue prevention.

    Science.gov (United States)

    Liu, Yang; Zhang, Fuchun; Liu, Jianying; Xiao, Xiaoping; Zhang, Siyin; Qin, Chengfeng; Xiang, Ye; Wang, Penghua; Cheng, Gong

    2014-02-01

    C-type lectins are a family of proteins with carbohydrate-binding activity. Several C-type lectins in mammals or arthropods are employed as receptors or attachment factors to facilitate flavivirus invasion. We previously identified a C-type lectin in Aedes aegypti, designated as mosquito galactose specific C-type lectin-1 (mosGCTL-1), facilitating the attachment of West Nile virus (WNV) on the cell membrane. Here, we first identified that 9 A. aegypti mosGCTL genes were key susceptibility factors facilitating DENV-2 infection, of which mosGCTL-3 exhibited the most significant effect. We found that mosGCTL-3 was induced in mosquito tissues with DENV-2 infection, and that the protein interacted with DENV-2 surface envelop (E) protein and virions in vitro and in vivo. In addition, the other identified mosGCTLs interacted with the DENV-2 E protein, indicating that DENV may employ multiple mosGCTLs as ligands to promote the infection of vectors. The vectorial susceptibility factors that facilitate pathogen invasion may potentially be explored as a target to disrupt the acquisition of microbes from the vertebrate host. Indeed, membrane blood feeding of antisera against mosGCTLs dramatically reduced mosquito infective ratio. Hence, the immunization against mosGCTLs is a feasible approach for preventing dengue infection. Our study provides a future avenue for developing a transmission-blocking vaccine that interrupts the life cycle of dengue virus and reduces disease burden.

  5. Transmission-blocking antibodies against mosquito C-type lectins for dengue prevention.

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2014-02-01

    Full Text Available C-type lectins are a family of proteins with carbohydrate-binding activity. Several C-type lectins in mammals or arthropods are employed as receptors or attachment factors to facilitate flavivirus invasion. We previously identified a C-type lectin in Aedes aegypti, designated as mosquito galactose specific C-type lectin-1 (mosGCTL-1, facilitating the attachment of West Nile virus (WNV on the cell membrane. Here, we first identified that 9 A. aegypti mosGCTL genes were key susceptibility factors facilitating DENV-2 infection, of which mosGCTL-3 exhibited the most significant effect. We found that mosGCTL-3 was induced in mosquito tissues with DENV-2 infection, and that the protein interacted with DENV-2 surface envelop (E protein and virions in vitro and in vivo. In addition, the other identified mosGCTLs interacted with the DENV-2 E protein, indicating that DENV may employ multiple mosGCTLs as ligands to promote the infection of vectors. The vectorial susceptibility factors that facilitate pathogen invasion may potentially be explored as a target to disrupt the acquisition of microbes from the vertebrate host. Indeed, membrane blood feeding of antisera against mosGCTLs dramatically reduced mosquito infective ratio. Hence, the immunization against mosGCTLs is a feasible approach for preventing dengue infection. Our study provides a future avenue for developing a transmission-blocking vaccine that interrupts the life cycle of dengue virus and reduces disease burden.

  6. C-type lectin interactions with Schistosoma mansoni SEA : Molecular basis and function

    NARCIS (Netherlands)

    Liempt, van P.A.G.

    2007-01-01

    Outline of this thesis The studies described in this thesis have been performed to gain more insight in the recognition of Schistosoma mansoni glycans by C-type lectins and the consequences for dendritic cell mediated immune responses. As a first approach to understand the molecular interactions o

  7. Computational and experimental prediction of human C-type lectin receptor druggability

    Directory of Open Access Journals (Sweden)

    Jonas eAretz

    2014-07-01

    Full Text Available Mammalian C-type lectin receptors are involved in many aspects of immune cell regulation such as pathogen recognition, clearance of apoptotic bodies and lymphocyte homing. Despite a great interest in modulating C-type lectin receptor recognition of carbohydrates, the number of specific molecular probes is limited. To this end, we predicted the druggability of a panel of 22 C-type lectin receptors using DoGSiteScorer. The computed druggability scores of most structures were low, characterizing this family as either challenging or even undruggable. To further explore these findings, we employed a fluorine-based NMR screening of fragment mixtures against DC-SIGN, a receptor of pharmacological interest. To our surprise, we found many fragment hits associated with the carbohydrate recognition site (hit rate = 13.5%. An SPR-based follow-up assay confirmed 18 of these fragments (47% and equilibrium dissociation constants were determined. Encouraged by these findings we expanded our experimental druggability prediction to Langerin and MCL and found medium to high hit rates as well, being 15.7% and 10.0%, respectively. Our results highlight limitations of current in silico approaches to druggability assessment, in particular with regard to carbohydrate-binding proteins. In sum, our data indicate that small molecule ligands for a larger panel of C-type lectin receptors can be developed.

  8. Molecular Characterization and Biological Effects of a C-Type Lectin-Like Receptor in Large Yellow Croaker (Larimichthys crocea

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    Jingqun Ao

    2015-12-01

    Full Text Available The C-type lectin-like receptors (CTLRs play important roles in innate immunity as one type of pattern recognition receptors. Here, we cloned and characterized a C-type lectin-like receptor (LycCTLR from large yellow croaker Larimichthys crocea. The full-length cDNA of LycCTLR is 880 nucleotides long, encoding a protein of 215 amino acids. The deduced LycCTLR contains a C-terminal C-type lectin-like domain (CTLD, an N-terminal cytoplasmic tail, and a transmembrane region. The CTLD of LycCTLR possesses six highly conserved cysteine residues (C1–C6, a conserved WI/MGL motif, and two sugar binding motifs, EPD (Glu-Pro-Asp and WYD (Trp-Tyr-Asp. Ca2+ binding site 1 and 2 were also found in the CTLD. The LycCTLR gene consists of five exons and four introns, showing the same genomic organization as tilapia (Oreochromis niloticus and guppy (Poecilia retitculata CTLRs. LycCTLR was constitutively expressed in various tissues tested, and its transcripts significantly increased in the head kidney and spleen after stimulation with inactivated trivalent bacterial vaccine. Recombinant LycCTLR (rLycCTLR protein produced in Escherichia coli BL21 exhibited not only the hemagglutinating activity and a preference for galactose, but also the agglutinating activity against two food-borne pathogenic bacteria E. coli and Bacillus cereus in a Ca2+-dependent manner. These results indicate that LycCTLR is a potential galactose-binding C-type lectin that may play a role in the antibacterial immunity in fish.

  9. The dendritic cell subtype-restricted C-type lectin Clec9A is a target for vaccine enhancement

    OpenAIRE

    Caminschi, Irina; Proietto, Anna I.; Ahmet, Fatma; Kitsoulis, Susie; Shin Teh, Joo; Lo, Jennifer C. Y.; Rizzitelli, Alexandra; Wu, Li; Vremec, David; van Dommelen, Serani L.H.; Campbell, Ian K.; Maraskovsky, Eugene; Braley, Hal; Davey, Gayle M.; Mottram, Patricia

    2008-01-01

    A novel dendritic cell (DC)–restricted molecule, Clec9A, was identified by gene expression profiling of mouse DC subtypes. Based on sequence similarity, a human ortholog was identified. Clec9A encodes a type II membrane protein with a single extracellular C-type lectin domain. Both the mouse Clec9A and human CLEC9A were cloned and expressed, and monoclonal antibodies (mAbs) against each were generated. Surface staining revealed that Clec9A was selective for mouse DCs and was restricted to the...

  10. A hepatopancreas-specific C-type lectin from the Chinese shrimp Fenneropenaeus chinensis exhibits antimicrobial activity.

    Science.gov (United States)

    Sun, Yun-Dong; Fu, Li-Dong; Jia, Yu-Ping; Du, Xin-Jun; Wang, Qian; Wang, Yu-Hang; Zhao, Xiao-Fan; Yu, Xiao-Qiang; Wang, Jin-Xing

    2008-01-01

    Lectins play important roles in animal innate immune responses by serving as pattern recognition receptors, opsonins, or effector molecules. Here, we report a novel hepatopancreas-specific C-type lectin, designated Fc-hsL, from the hepatopancreas of the Chinese shrimp, Fenneropenaeus chinensis. The cDNA of Fc-hsL is 571 bp long with a 480 bp open reading frame that encodes a 159-residue protein. Fc-hsL contains a signal peptide and a single C-type lectin-like domain (CTLD) or carbohydrate recognition domain (CRD). It has an EPN(Glu-Pro-Asn) motif with a predicted ligand-binding site specific for mannose. Fc-hsL was constitutively expressed in the hepatopancreas of normal shrimp, and its expression was up-regulated following challenge of shrimp with bacteria or virus. Fc-hsL was not detected in other tissues but was induced in the stomach of immune-challenged shrimp. Fc-hsL protein was detected in both hemolymph and the hepatopancreas of bacteria- and virus-challenged shrimp. Recombinant mature Fc-hsL has no hemagglutinating activity, but calcium-dependent agglutinating activity against some Gram-positive and Gram-negative bacteria was detected. The rFc-hsL also has binding activity to some Gram-positive and Gram-negative bacteria and high antimicrobial activity against some bacteria and fungi. These in vitro functions of recombinant Fc-hsL were calcium-independent. Fc-hsL may act as a pattern recognition receptor in antibacterial defense and as an effector in innate immunity of Chinese shrimp.

  11. Molecular cloning and expression of a C-type lectin-like protein from orange-spotted grouper Epinephelus coioides.

    Science.gov (United States)

    Ji, H; Wei, J; Wei, S; Yan, Y; Huang, Y; Huang, X; Zhou, S; Zhou, Y; Qin, Q

    2014-02-01

    A C-type lectin-like protein (Ec-CTLP) was cloned from the grouper Epinephelus coioides. The full-length cDNA of Ec-CTLP was composed of 905 bp with a 522 bp open reading frame that encodes a 174-residue protein. The putative amino acid sequence of Ec-CTLP contains a signal peptide of 19 residues at the N-terminus and a CLECT domain from Cys43 to Arg169 and a conserved imperfect WND (Trp-Asn-Asp) motif. The homologous identity of deduced amino acid sequences is from 32 to 42% with other fishes. The expression of Ec-CTLP was differently upregulated in E. coioides spleen (germline stem) cells after being challenged at 16 and 4° C. Intracellular localization revealed that Ec-CTLP was distributed only in the cytoplasm. Recombinant Ec-CTLP (rEc-CTLP) was expressed in Escherichia coli BL21 (DE3) and purified for mouse Mus musculus anti-Ec-CTLP serum preparation. The rEc-CTLP fusion protein does not possess haemagglutinating activity, but improves survival from frozen bacteria. The survival of bacteria (including gram-negative E. coli and gram-positive Staphylococcus aureus) was positively correlated with the concentration of the rEc-CTLP. These findings can provide clues to help understand the probable C-type lectin in marine fish innate immunity.

  12. cDNA cloning,sequence analysis,and recombinant expression of akitonin beta,a C-type lectin-like protein from Agkistrodon acutus

    Institute of Scientific and Technical Information of China (English)

    Xiang-dong ZHA; Jing LIU; Kang-sen XU

    2004-01-01

    AIM: To clone the cDNA of a new member of snake venom C-type lectin-like proteins, to study its structurefunction relationships and to achieve its recombinant production. METHODS: PCR primers were designed based on the homology and cDNA was amplified by RT-PCR using total RNA from snake venom gland as the template.The PCR products were cloned into the plasmid pGEM-T and sequenced. The deduced protein sequence was analyzed with some bioinformatic programs. A recombinant expression plasmid was constructed using pBADTOPO as vector and transformed into E. coli TOP10 competent cells. RESULTS: A novel cDNA sequence encoding akitonin β was found and accepted by GenBank (accession number AF387100). Akitonin β consists of a typical carbohydrate recognition domain (CRD) of C-type lectins, and it is homologous with other snake venom C-type lectin-like proteins. It was predicted to be a platelet antagonist. Upon induction with arabinose rAkitonin β expressing in E coli was achieved at a high level (superior to 150 mg/L). The recombinant fusion protein exhibited inhibitory activities on rat platelet aggregation in vitro. CONCLUSION: A new member of snake venom C-type lectin-like proteins was discovered and characterized, and an efficient recombinant expression system was established for its production.

  13. A scallop C-type lectin from Argopecten irradians (AiCTL5) with activities of lipopolysaccharide binding and Gram-negative bacteria agglutination.

    Science.gov (United States)

    Mu, Changkao; Song, Xiaoyan; Zhao, Jianmin; Wang, Lingling; Qiu, Limei; Zhang, Huan; Zhou, Zhi; Wang, Mengqiang; Song, Linsheng; Wang, Chunlin

    2012-05-01

    C-type lectins are a family of calcium-dependent carbohydrate-binding proteins. In the present study, a C-type lectin (designated as AiCTL5) was identified and characterized from Argopecten irradians. The full-length cDNA of AiCTL5 was of 673 bp, containing a 5' untranslated region (UTR) of 24 bp, a 3' UTR of 130 bp with a poly (A) tail, and an open reading frame (ORF) of 519 bp encoding a polypeptide of 172 amino acids with a putative signal peptide of 17 amino acids. A C-type lectin-like domain (CRD) containing 6 conserved cysteines and a putative glycosylation sites were identified in the deduced amino acid sequence of AiCTL5. AiCTL5 shared 11%-27.5% identity with the previous reported C-type lectin from A. irradians. The cDNA fragment encoding the mature peptide of AiCTL5 was recombined into pET-21a (+) with a C-terminal hexa-histidine tag fused in-frame, and expressed in Escherichia coli Origami (DE3). The recombinant AiCTL5 (rAiCTL5) agglutinated Gram-negative E. coli TOP10F' and Listonella anguillarum, but did not agglutinate Gram-positive bacteria Bacillus thuringiensis and Micrococcus luteus, and the agglutination could be inhibited by EDTA, indicating that AiCTL5 was a Ca(2+)-dependent lectin. rAiCTL5 exhibited a significantly strong activity to bind LPS from E. coli, which conformed to the agglutinating activity toward Gram-negative bacteria. Moreover, rAiCTL5 also agglutinated rabbit erythrocytes. These results indicated that AiCTL5 could function as a pattern recognition receptor to protect bay scallop from Gram-negative bacterial infection, and also provide evidence to understand the structural and functional diverse of lectin.

  14. Immune response of four dual-CRD C-type lectins to microbial challenges in giant freshwater prawn Macrobrachium rosenbergii.

    Science.gov (United States)

    Ren, Qian; Li, Meng; Du, Jie; Zhang, Chi-Yu; Wang, Wen

    2012-08-01

    C-type lectins (CTLs) are believed to play important roles in the innate immunity of invertebrates and serve as pattern recognition receptors, opsonins, or effector molecules. In this study, the full-lengths cDNA of 4 CTL genes from giant freshwater prawn Macrobrachium rosenbergii were cloned and designated as MrLec1, MrLec2, MrLec3, and MrLec4. All of these 4 lectin cDNAs encode proteins with 2 carbohydrate recognition domains (CRDs). While MrLec1, MrLec3, and MrLec4 had signal peptides, no signal peptide was detected in MrLec2. Two carbohydrate recognition motifs within two CRDs of each lectin were predicted (QPE, EPG in MrLec1; EPT, EPA in MrLec2; QPT, NPR in MrLec3; KPN, EPD in MrLec4). Phylogenetic analysis showed that MrLec4 belongs to group A whereas MrLec1, MrLec2, and MrLec3 belong to group B. Positive selection in dual-CRD lectins suggested their probable roles in innate immunity, and positively selected induced amino acid diversity of lectins may confer their ability to recognize a broad range of microbes. The qRT-PCR analysis in adult prawns showed that MrLec1 is mainly expressed in the hepatopancreas, gills, and stomach, MrLec2 and MrLec4 are mainly distributed in the hepatopancreas, and MrLec3 is mainly expressed in the hepatopancreas and stomach. Time-course analysis using qRT-PCR showed that MrLec1 to MrLec4 are all upregulated by the Vibrio anguillarum challenge. MrLec1 is upregulated after 2, 12, and 24 h of white spot syndrome virus (WSSV) challenge. The expression of MrLec2 increases after 12 and 24 h of WSSV challenge, and the transcript of MrLec3 and MrLec4 are downregulated after 2 h of WSSV challenge. The results suggest the potential roles of dual-CRD lectins in the innate immunity of M. rosenbergii.

  15. A C-type lectin isolated from the skin of Japanese bullhead shark (Heterodontus japonicus) binds a remarkably broad range of sugars and induces blood coagulation.

    Science.gov (United States)

    Tsutsui, Shigeyuki; Dotsuta, Yuma; Ono, Ayaka; Suzuki, Masanari; Tateno, Hiroaki; Hirabayashi, Jun; Nakamura, Osamu

    2015-05-01

    The aim of this study was to determine the physiological role of skin lectins of the Japanese bullhead shark (Heterodontus japonicus). A skin extract was subjected to affinity chromatography using seven different sugars as ligands. Molecular mass and N-terminal amino acid sequence analyses indicated elution of the same protein by each of the seven respective cognate ligands from sugar affinity columns. The predicted amino acid sequence encoded by the cDNA of this protein [designated as H. japonicus C-type-lectin (HjCL)] identified it as a novel fish subgroup VII C-type lectin evolutionarily related to snake venom lectins. HjCL was predicted to bind to mannose because of the presence of a Glu-Pro-Asn (EPN) motif; however, haemagglutination inhibition assays and glycoconjugate microarray analysis demonstrated its binding to numerous structurally diverse sugars. Competitive sugar-binding assays using affinity chromatography indicated that HjCL bound multiple sugars via a common carbohydrate-recognition domain. The mRNA encoding HjCL was specifically detected in the skin, and immunohistochemical analysis detected its expression in uncharacterized large cells in the epidermis. HjCL agglutinated the bacterial pathogen Edwardsiella tarda and promoted immediate clotting of shark blood, indicating that HjCL is involved in host defence on the skin surface especially when the shark is injured and bleeds.

  16. C-type lectin receptors and RIG-I-like receptors: new points on the oncogenomics map

    Directory of Open Access Journals (Sweden)

    Yuzhalin AE

    2012-02-01

    Full Text Available Anton G Kutikhin, Arseniy E YuzhalinDepartment of Epidemiology, Kemerovo State Medical Academy, Kemerovo, Russian FederationAbstract: The group of pattern recognition receptors includes families of Toll-like receptors, NOD-like receptors, C-type lectin receptors, and RIG-I-like receptors. They are key sensors for a number of infectious agents, some of which are oncogenic, and they launch an immune response against them, normally promoting their eradication. Inherited variations in genes encoding these receptors and proteins and their signaling pathways may affect their function, possibly modulating cancer risk and features of cancer progression. There are numerous studies investigating the association of single nucleotide polymorphisms within or near genes encoding Toll-like receptors and NOD-like receptors, cancer risk, and features of cancer progression. However, there is an almost total absence of articles analyzing the correlation between polymorphisms of genes encoding C-type lectin receptors and RIG-I-like receptors and cancer risk or progression. Nevertheless, there is some evidence supporting the hypothesis that inherited C-type lectin receptor and RIG-I-like receptor variants can be associated with increased cancer risk. Certain C-type lectin receptors and RIG-I-like receptors recognize pathogen-associated molecular patterns of potentially oncogenic infectious agents, and certain polymorphisms of genes encoding C-type lectin receptors and RIG-I-like receptors may have functional consequences at the molecular level that can lead to association of such single nucleotide polymorphisms with risk or progression of some diseases that may modulate cancer risk, so these gene polymorphisms may affect cancer risk indirectly. Polymorphisms of genes encoding C-type lectin receptors and RIG-I-like receptors thereby may be correlated with a risk of lung, oral, esophageal, gastric, colorectal, and liver cancer, as well as nasopharyngeal carcinoma

  17. Macrophage-inducible C-type lectin underlies obesity-induced adipose tissue fibrosis.

    Science.gov (United States)

    Tanaka, Miyako; Ikeda, Kenji; Suganami, Takayoshi; Komiya, Chikara; Ochi, Kozue; Shirakawa, Ibuki; Hamaguchi, Miho; Nishimura, Satoshi; Manabe, Ichiro; Matsuda, Takahisa; Kimura, Kumi; Inoue, Hiroshi; Inagaki, Yutaka; Aoe, Seiichiro; Yamasaki, Sho; Ogawa, Yoshihiro

    2014-09-19

    In obesity, a paracrine loop between adipocytes and macrophages augments chronic inflammation of adipose tissue, thereby inducing systemic insulin resistance and ectopic lipid accumulation. Obese adipose tissue contains a unique histological structure termed crown-like structure (CLS), where adipocyte-macrophage crosstalk is known to occur in close proximity. Here we show that Macrophage-inducible C-type lectin (Mincle), a pathogen sensor for Mycobacterium tuberculosis, is localized to macrophages in CLS, the number of which correlates with the extent of interstitial fibrosis. Mincle induces obesity-induced adipose tissue fibrosis, thereby leading to steatosis and insulin resistance in liver. We further show that Mincle in macrophages is crucial for CLS formation, expression of fibrosis-related genes and myofibroblast activation. This study indicates that Mincle, when activated by an endogenous ligand released from dying adipocytes, is involved in adipose tissue remodelling, thereby suggesting that sustained interactions between adipocytes and macrophages within CLS could be a therapeutic target for obesity-induced ectopic lipid accumulation.

  18. The Macrophage Galactose-Type C-Type Lectin (MGL Modulates Regulatory T Cell Functions.

    Directory of Open Access Journals (Sweden)

    Ilaria Grazia Zizzari

    Full Text Available Regulatory T cells (Tregs are physiologically designed to prevent autoimmune disease and maintain self-tolerance. In tumour microenvironments, their presence is related to a poor prognosis, and they influence the therapeutic outcome due to their capacity to suppress the immune response by cell-cell contact and to release immunosuppressive cytokines. In this study, we demonstrate that Treg immunosuppressive activity can be modulated by the cross-linking between the CD45RA expressed by Tregs and the C-type lectin MGL. This specific interaction strongly decreases the immunosuppressive activity of Tregs, restoring the proliferative capacity of co-cultured T lymphocytes. This effect can be attributed to changes in CD45RA and TCR signalling through the inhibition of Lck and inactivation of Zap-70, an increase in the Foxp3 methylation status and, ultimately, the reduced production of suppressive cytokines. These results indicate a role of MGL as an immunomodulator within the tumour microenvironment interfering with Treg functions, suggesting its possible use in the design of anticancer vaccines.

  19. Differential expression of skin mucus C-type lectin in two freshwater eel species, Anguilla marmorata and Anguilla japonica.

    Science.gov (United States)

    Tsutsui, Shigeyuki; Yoshinaga, Tatsuki; Komiya, Kaoru; Yamashita, Hiroka; Nakamura, Osamu

    2016-08-01

    Two types of lactose-specific lectins, galectin (AJL-1) and C-type lectin (AJL-2), were previously identified in the mucus of adult Anguilla japonica. Here, we compared the expression profiles of these two homologous lectins at the adult and juvenile stages between the tropical eel Anguilla marmorata and the temperate eel A. japonica. Only one lectin, predicted to be an orthologue of AJL-1 by LC-MS/MS, was detected in the mucus of adult A. marmorata. We also found that an orthologous gene to AJL-2 was expressed at very low levels, or not at all, in the skin of adult A. marmorata. However, we detected the gene expression of an AJL-2-orthologue in the skin of juvenile A. marmorata, and a specific antibody also detected the lectin in the juvenile fish epidermis. These findings suggest that expression profiles of mucosal lectins vary during development as well as between species in the Anguilla genus.

  20. The skeletal proteome of the brittle star Ophiothrix spiculata identifies C-type lectins and other proteins conserved in echinoderm skeleton formation

    Directory of Open Access Journals (Sweden)

    Brian T. Livingston

    2016-07-01

    Full Text Available Determining the identity and functional role of proteins involved in biomineralization and the formation of skeletons is critical to our understanding of the process. Proteomics has allowed rapid characterization of the proteins occluded within mineralized tissue, but the large numbers of proteins detected makes it difficult to assign the relative importance of each protein. We have taken a comparative approach, examining the skeletal proteome of different species of echinoderms in order to identify the proteins that are conserved and likely to be important. Our previous study comparing the skeletal proteome of the brittle star Ophiocoma wendtii to the published proteomes of the sea urchin Strongylocentrotus purpuratus revealed some conservation of proteins, but indicated that the C-type lectin domain-containing spicule matrix proteins abundant in the sea urchin skeletal proteome were not conserved in the brittle star. Here we examine the skeletal proteome of a different species of brittle star, Ophiothrix spiculata. We have isolated the proteins from the skeleton of O. spiculata and performed LC/MS/MS to identify peptides present. Comparison to transcriptome and genome databases revealed the proteins present in the O. spiculata proteome. Despite being diverged for several million years, the two brittle stars have very similar proteins in their skeletons. Included is a fibrinogen C-like lectin and several C-type lectins proteins, which we describe in detail. The unusual number of C-type lectins found in the S. purpuatus skeleton and the repetitive regions seen in those spicule matrix proteins are not present in O. spiculata.

  1. A shrimp C-type lectin inhibits proliferation of the hemolymph microbiota by maintaining the expression of antimicrobial peptides.

    Science.gov (United States)

    Wang, Xian-Wei; Xu, Ji-Dong; Zhao, Xiao-Fan; Vasta, Gerardo Raul; Wang, Jin-Xing

    2014-04-25

    Some aquatic invertebrates such as shrimp contain low albeit stable numbers of bacteria in the circulating hemolymph. The proliferation of this hemolymph microbiota in such a nutrient-rich environment is tightly controlled in healthy animals, but the mechanisms responsible had remained elusive. In the present study, we report a C-type lectin (MjHeCL) from the kuruma shrimp (Marsupenaeus japonicus) that participates in restraining the hemolymph microbiota. Although the expression of MjHeCL did not seem to be modulated by bacterial challenge, the down-regulation of its expression by RNA interference led to proliferation of the hemolymph microbiota, ultimately resulting in shrimp death. This phenotype was rescued by the injection of recombinant MjHeCL, which restored the healthy status of the knockdown shrimp. A mechanistic analysis revealed that MjHeCL inhibited bacterial proliferation by modulating the expression of antimicrobial peptides. The key function of MjHeCL in the shrimp immune homeostasis might be related to its broader recognition spectrum of the hemolymph microbiota components than other lectins. Our study demonstrates the role of MjHeCL in maintaining the healthy status of shrimp and provides new insight into the biological significance of C-type lectins, a diversified and abundant lectin family in invertebrate species.

  2. E3 ubiquitin ligase CHIP interacts with C-type lectin-like receptor CLEC-2 and promotes its ubiquitin-proteasome degradation.

    Science.gov (United States)

    Shao, Miaomiao; Li, Lili; Song, Shushu; Wu, Weicheng; Peng, Peike; Yang, Caiting; Zhang, Mingming; Duan, Fangfang; Jia, Dongwei; Zhang, Jie; Wu, Hao; Zhao, Ran; Wang, Lan; Ruan, Yuanyuan; Gu, Jianxin

    2016-10-01

    C-type lectin-like receptor 2 (CLEC-2) was originally identified as a member of non-classical C-type lectin-like receptors in platelets and immune cells. Activation of CLEC-2 is involved in thrombus formation, lymphatic/blood vessel separation, platelet-mediated tumor metastasis and immune response. Nevertheless, the regulation of CLEC-2 expression is little understood. In this study, we identified that the C terminus of Hsc70-interacting protein (CHIP) interacted with CLEC-2 by mass spectrometry analysis, and CHIP decreased the protein expression of CLEC-2 through lysine-48-linked ubiquitination and proteasomal degradation. Deleted and point mutation also revealed that CHIP controlled CLEC-2 protein expression via both tetratricopeptide repeats (TPR) domain and Ubox domain in a HSP70/90-independent manner. Moreover, reduced CHIP expression was associated with decreased CLEC-2 polyubiquitination and increased CLEC-2 protein levels in PMA-induced differentiation of THP-1 monocytes into macrophages. These results indicate that CLEC-2 is the target substrate of E3 ubiquitin ligase CHIP, and suggest that the CHIP/CLEC-2 axis may play an important role in the modulation of immune response.

  3. Lectin domains at the frontiers of plant defense

    Directory of Open Access Journals (Sweden)

    Nausicaä eLANNOO

    2014-08-01

    Full Text Available Plants are under constant attack from pathogens and herbivorous insects. To protect and defend themselves, plants evolved a multi-layered surveillance system, known as the innate immune system. Plants sense their encounters upon perception of conserved microbial structures and damage-associated patterns using cell-surface and intracellular immune receptors. Plant lectins and proteins with one or more lectin domains represent a major part of these receptors. The whole group of plant lectins comprises an elaborate collection of proteins capable of recognizing and interacting with specific carbohydrate structures, either originating from the invading organisms or from damaged plant cell wall structures. Due to the vast diversity in protein structures, carbohydrate recognition domains and glycan binding specificities, plant lectins constitute a very diverse protein superfamily. In the last decade, new types of nucleocytoplasmic plant lectins have been identified and characterized, in particular lectins expressed inside the nucleus and the cytoplasm of plant cells often as part of a specific plant response upon exposure to different stress factors or changing environmental conditions. In this review, we provide an overview on plant lectin motifs used in the constant battle against pathogens and predators during plant defenses.

  4. Epidermal Langerhans cells rapidly capture and present antigens from C-type lectin-targeting antibodies deposited in the dermis.

    Science.gov (United States)

    Flacher, Vincent; Tripp, Christoph H; Stoitzner, Patrizia; Haid, Bernhard; Ebner, Susanne; Del Frari, Barbara; Koch, Franz; Park, Chae Gyu; Steinman, Ralph M; Idoyaga, Juliana; Romani, Nikolaus

    2010-03-01

    Antigen-presenting cells can capture antigens that are deposited in the skin, including vaccines given subcutaneously. These include different dendritic cells (DCs) such as epidermal Langerhans cells (LCs), dermal DCs, and dermal langerin+ DCs. To evaluate access of dermal antigens to skin DCs, we used mAb to two C-type lectin endocytic receptors, DEC-205/CD205 and langerin/CD207. When applied to murine and human skin explant cultures, these mAbs were efficiently taken up by epidermal LCs. In addition, anti-DEC-205 targeted langerin+ CD103+ and langerin- CD103- mouse dermal DCs. Unexpectedly, intradermal injection of either mAb, but not isotype control, resulted in strong and rapid labeling of LCs in situ, implying that large molecules can diffuse through the basement membrane into the epidermis. Epidermal LCs targeted in vivo by ovalbumin-coupled anti-DEC-205 potently presented antigen to CD4+ and CD8+ T cells in vitro. However, to our surprise, LCs targeted through langerin were unable to trigger T-cell proliferation. Thus, epidermal LCs have a major function in uptake of lectin-binding antibodies under standard vaccination conditions.

  5. Molecular cloning and characterization of a C-type lectin from Ancylostoma ceylanicum: evidence for a role in hookworm reproductive physiology.

    Science.gov (United States)

    Brown, Allison C.; Harrison, Lisa M.; Kapulkin, Wadim; Jones, Brian F.; Sinha, Anindita; Savage, Amy; Villalon, Nicholas; Cappello, Michael

    2007-01-01

    Lectins comprise a family of related proteins that mediate essential cell functions through binding to carbohydrates. Within this protein family, C-type lectins are defined by the requirement of calcium for optimal biologic activity. Using reverse transcription PCR, a cDNA corresponding to a putative C-type lectin has been amplified from the hookworm parasite Ancylostoma ceylanicum. The 550 nucleotide open reading frame of the Ancylostoma ceylanicum C-type Lectin-1 (AceCTL-1) cDNA corresponds to a 167 amino acid mature protein (18706 Da) preceded by a 17 amino acid secretory signal sequence. The recombinant protein (rAceCTL-1) was expressed in Drosophila S2 cells and purified using a combination of affinity chromatography and reverse phase HPLC. Using in vitro carbohydrate binding studies, it was determined that rAceCTL-1 binds N-acetyl-D-glucosamine, a common component of eukaryotic egg cell membranes. Using a polyclonal IgG raised against the recombinant protein, the native AceCTL-1 was identified in sperm and soluble protein extracts of adult male A. ceylanicum by immunoblot. Probing of adult hookworm sections with the polyclonal IgG demonstrated localization to the testes in males, as well as the spermatheca and developing embryos in females, consistent with its role as a sperm protein. Together, these data strongly suggest that AceCTL-1 is a male gender-specific C-type lectin with a function in hookworm reproductive physiology. PMID:17129620

  6. Lactobacillus reuteri Surface Mucus Adhesins Upregulate Inflammatory Responses Through Interactions With Innate C-Type Lectin Receptors.

    Science.gov (United States)

    Bene, Krisztián P; Kavanaugh, Devon W; Leclaire, Charlotte; Gunning, Allan P; MacKenzie, Donald A; Wittmann, Alexandra; Young, Ian D; Kawasaki, Norihito; Rajnavolgyi, Eva; Juge, Nathalie

    2017-01-01

    The vertebrate gut symbiont Lactobacillus reuteri exhibits strain-specific adhesion and health-promoting properties. Here, we investigated the role of the mucus adhesins, CmbA and MUB, upon interaction of L. reuteri ATCC PTA 6475 and ATCC 53608 strains with human monocyte-derived dendritic cells (moDCs). We showed that mucus adhesins increased the capacity of L. reuteri strains to interact with moDCs and promoted phagocytosis. Our data also indicated that mucus adhesins mediate anti- and pro-inflammatory effects by the induction of interleukin-10 (IL-10), tumor necrosis factor alpha (TNF-α), IL-1β, IL-6, and IL-12 cytokines. L. reuteri ATCC PTA 6475 and ATCC 53608 were exclusively able to induce moDC-mediated Th1 and Th17 immune responses. We further showed that purified MUB activates moDCs and induces Th1 polarized immune responses associated with increased IFNγ production. MUB appeared to mediate these effects via binding to C-type lectin receptors (CLRs), as shown using cell reporter assays. Blocking moDCs with antibodies against DC-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) or Dectin-2 did not affect the uptake of the MUB-expressing strain, but reduced the production of TNF-α and IL-6 by moDCs significantly, in line with the Th1 polarizing capacity of moDCs. The direct interaction between MUB and CLRs was further confirmed by atomic force spectroscopy. Taken together these data suggest that mucus adhesins expressed at the cell surface of L. reuteri strains may exert immunoregulatory effects in the gut through modulating the Th1-promoting capacity of DCs upon interaction with C-type lectins.

  7. Identification of a novel C-type lectin from the shrimp Litopenaeus vannamei and its role in defense against pathogens infection

    Institute of Scientific and Technical Information of China (English)

    LUO Zhan; ZHANG Jiquan; LI Fuhua; ZHANG Xiaojun; LIU Chengzhang; XIANG Jianhai

    2011-01-01

    Acting as one of the pattern recognition receptors (PRRs),C-type lectin is believed to mediate pathogen recognition and plays an important role in the clearance of pathogens as part of the innate immune system.In this work,a novel C-type lectin gene (named LvLecl) was cloned from the shrimp Litopenaeus vannamei.The ORF of LvLecl is 510 bp,encoding 169 amino acids.The deduced amino acid sequence contains a putative signal peptide of 19 amino acids at the N-terminal and a carbohydrate recognition domain (CRD) at the C-terminal.LvLecl was mainly expressed in the hepatopancreas.Real-time PCR analysis indicated that the level of LvLecl transcripts significantly changed in the hepatopancreas after the shrimp were artificially challenged with LPS,Micrococcus lysodeikticus and white spot syndrome virus (WSSV).RNAi-based silencing of LvLecl resulted in increases in mortality when the shrimp were challenged with WSSV,and the median lethal time was reduced compared with controls.Although there was no characteristic “EPN” (Glu-Pro-Ser) or “QPD” (Gln-Pro-Asp) motif,the recombinant LvLecl,expressed in Escherichia coli BL21 (DE3),could also agglutinate M.lysodeikticus and Vibrio anguillarum.The agglutinating activities were calcium-dependent and could be inhibited by D-mannose,D-glucose,D-galactose and N-Acetyl-D-mannose.These results suggest that LvLecl might be involved in the immune response against WSSV and bacterial infections and contribute to non-self recognition as a pattem recognition receptor in the innate immune system of the shrimp L.vannamei.

  8. The dendritic cell-specific C-type lectin DC-SIGN is a receptor for Schistosoma mansoni egg antigens and recognizes the glycan antigen Lewis x.

    NARCIS (Netherlands)

    Die, van I.M.; Vliet, van SJ; Nyame, AK; Cummings, RD; Bank, CM; Appelmelk, B.J.; Geijtenbeek, T.B.H.; Kooijk, van Y.

    2003-01-01

    Schistosoma mansoni soluble egg antigens (SEAs) are crucially involved in modulating the host immune response to infection by S. mansoni. We report that human dendritic cells bind SEAs through the C-type lectin dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN). Monoclonal antibodies agai

  9. CLEC4F Is an Inducible C-Type Lectin in F4/80-Positive Cells and Is Involved in Alpha-Galactosylceramide Presentation in Liver

    NARCIS (Netherlands)

    Yang, C.Y.; Chen, J.B.; Tsai, T.F.; Tsai, Y.C.; Tsai, C.Y.; Liang, P.H.; Hsu, T.L.; Wu, C.Y.; Netea, M.G.; Wong, C.H.; Hsieh, S.L.

    2013-01-01

    CLEC4F, a member of C-type lectin, was first purified from rat liver extract with high binding affinity to fucose, galactose (Gal), N-acetylgalactosamine (GalNAc), and un-sialylated glucosphingolipids with GalNAc or Gal terminus. However, the biological functions of CLEC4F have not been elucidated.

  10. The C-Type Lectin Receptor MCL Mediates Vaccine-Induced Immunity against Infection with Blastomyces dermatitidis.

    Science.gov (United States)

    Wang, Huafeng; Li, Mengyi; Lerksuthirat, Tassanee; Klein, Bruce; Wüthrich, Marcel

    2015-12-14

    C-type lectin receptors (CLRs) are essential in shaping the immune response to fungal pathogens. Vaccine-induced resistance requires Dectin-2 to promote differentiation of antifungal Th1 and Th17 cells. Since Dectin-2 and MCL heterodimerize and both CLRs use FcRγ as the signaling adaptor, we investigated the role of MCL in vaccine immunity to the fungal pathogen Blastomyces dermatitidis. MCL(-/-) mice showed impaired vaccine resistance against B. dermatitidis infection compared to that of wild-type animals. The lack of resistance correlated with the reduced recruitment of Th17 cells to the lung upon recall following experimental challenge and impaired interleukin-17 (IL-17) production by vaccine antigen-stimulated splenocytes in vitro. Soluble MCL fusion protein recognized and bound a water-soluble ligand from the cell wall of vaccine yeast, but the addition of soluble Dectin-2 fusion protein did not augment ligand recognition by MCL. Taken together, our data indicate that MCL regulates the development of vaccine-induced Th17 cells and protective immunity against lethal experimental infection with B. dermatitidis.

  11. Mechanistic insights into the role of C-type lectin receptor/CARD9 signaling in human antifungal immunity

    Directory of Open Access Journals (Sweden)

    Rebecca A. Drummond

    2016-04-01

    Full Text Available Human CARD9 deficiency is an autosomal recessive primary immunodeficiency disorder caused by biallelic mutations in the gene CARD9, which encodes a signaling protein that is found downstream of many C-type lectin receptors (CLRs. CLRs encompass a large family of innate recognition receptors, expressed predominantly by myeloid and epithelial cells, which bind fungal carbohydrates and initiate antifungal immune responses. Accordingly, human CARD9 deficiency is associated with the spontaneous development of persistent and severe fungal infections that primarily localize to the skin and subcutaneous tissue, mucosal surfaces and/or central nervous system (CNS. In the last few years, more than 15 missense and nonsense CARD9 mutations have been reported which associate with the development of a wide spectrum of fungal infections caused by a variety of fungal organisms. The mechanisms by which CARD9 provides organ-specific protection against these fungal infections are now emerging. In this review, we summarize recent immunological and clinical advances that have provided significant mechanistic insights into the pathogenesis of human CARD9 deficiency. We also discuss how genetic mutations in CARD9-coupled receptors (Dectin-1, Dectin-2 and CARD9-binding partners (MALT1, BCL10 affect human antifungal immunity relative to CARD9 deficiency, and we highlight major understudied research questions which merit future investigation.

  12. C-type lectin like receptor 2 (CLEC-2) signals independently of lipid raft microdomains in platelets.

    Science.gov (United States)

    Manne, Bhanu Kanth; Badolia, Rachit; Dangelmaier, Carol A; Kunapuli, Satya P

    2015-01-15

    C-type lectin like receptor 2 (CLEC-2) has been reported to activate platelets through a lipid raft-dependent manner. Secreted ADP potentiates CLEC-2-mediated platelet aggregation. We have investigated whether the decrease in CLEC-2-mediated platelet aggregation, previously reported in platelets with disrupted rafts, is a result of the loss of agonist potentiation by ADP. We disrupted platelet lipid rafts with methyl-β-cyclodextrin (MβCD) and measured signaling events downstream of CLEC-2 activation. Lipid raft disruption decreases platelet aggregation induced by CLEC-2 agonists. The inhibition of platelet aggregation by the disruption of lipid rafts was rescued by the exogenous addition of epinephrine but not 2-methylthioadenosine diphosphate (2MeSADP), which suggests that lipid raft disruption effects P2Y12-mediated Gi activation but not Gz. Phosphorylation of Syk (Y525/526) and PLCγ2 (Y759), were not affected by raft disruption in CLEC-2 agonist-stimulated platelets. Furthermore, tyrosine phosphorylation of the CLEC-2 hemi-ITAM was not effected when MβCD disrupts lipid rafts. Lipid rafts do not directly contribute to CLEC-2 receptor activation in platelets. The effects of disruption of lipid rafts in in vitro assays can be attributed to inhibition of ADP feedback that potentiates CLEC-2 signaling.

  13. Hemolytic C-type lectin CEL-III from sea cucumber expressed in transgenic mosquitoes impairs malaria parasite development.

    Directory of Open Access Journals (Sweden)

    Shigeto Yoshida

    2007-12-01

    Full Text Available The midgut environment of anopheline mosquitoes plays an important role in the development of the malaria parasite. Using genetic manipulation of anopheline mosquitoes to change the environment in the mosquito midgut may inhibit development of the malaria parasite, thus blocking malaria transmission. Here we generate transgenic Anopheles stephensi mosquitoes that express the C-type lectin CEL-III from the sea cucumber, Cucumaria echinata, in a midgut-specific manner. CEL-III has strong and rapid hemolytic activity toward human and rat erythrocytes in the presence of serum. Importantly, CEL-III binds to ookinetes, leading to strong inhibition of ookinete formation in vitro with an IC(50 of 15 nM. Thus, CEL-III exhibits not only hemolytic activity but also cytotoxicity toward ookinetes. In these transgenic mosquitoes, sporogonic development of Plasmodium berghei is severely impaired. Moderate, but significant inhibition was found against Plasmodium falciparum. To our knowledge, this is the first demonstration of stably engineered anophelines that affect the Plasmodium transmission dynamics of human malaria. Although our laboratory-based research does not have immediate applications to block natural malaria transmission, these findings have significant implications for the generation of refractory mosquitoes to all species of human Plasmodium and elucidation of mosquito-parasite interactions.

  14. C-type Lectin Mincle Recognizes Glucosyl-diacylglycerol of Streptococcus pneumoniae and Plays a Protective Role in Pneumococcal Pneumonia.

    Science.gov (United States)

    Behler-Janbeck, Friederike; Takano, Tomotsugu; Maus, Regina; Stolper, Jennifer; Jonigk, Danny; Tort Tarrés, Meritxell; Fuehner, Thomas; Prasse, Antje; Welte, Tobias; Timmer, Mattie S M; Stocker, Bridget L; Nakanishi, Yoichi; Miyamoto, Tomofumi; Yamasaki, Sho; Maus, Ulrich A

    2016-12-01

    Among various innate immune receptor families, the role of C-type lectin receptors (CLRs) in lung protective immunity against Streptococcus pneumoniae (S. pneumoniae) is not fully defined. We here show that Mincle gene expression was induced in alveolar macrophages and neutrophils in bronchoalveolar lavage fluids of mice and patients with pneumococcal pneumonia. Moreover, S. pneumoniae directly triggered Mincle reporter cell activation in vitro via its glycolipid glucosyl-diacylglycerol (Glc-DAG), which was identified as the ligand recognized by Mincle. Purified Glc-DAG triggered Mincle reporter cell activation and stimulated inflammatory cytokine release by human alveolar macrophages and alveolar macrophages from WT but not Mincle KO mice. Mincle deficiency led to increased bacterial loads and decreased survival together with strongly dysregulated cytokine responses in mice challenged with focal pneumonia inducing S. pneumoniae, all of which was normalized in Mincle KO mice reconstituted with a WT hematopoietic system. In conclusion, the Mincle-Glc-DAG axis is a hitherto unrecognized element of lung protective immunity against focal pneumonia induced by S. pneumoniae.

  15. Macrophage inducible C-type lectin (Mincle) recognizes glycosylated surface (S)-layer of the periodontal pathogen Tannerella forsythia

    Science.gov (United States)

    Chinthamani, Sreedevi; Settem, Rajendra P.; Honma, Kiyonobu; Kay, Jason G.

    2017-01-01

    The oral pathogen Tannerella forsythia is implicated in the development of periodontitis, a common inflammatory disease that leads to the destruction of the gum and tooth supporting tissues, often leading to tooth loss. T. forsythia is a unique Gram-negative organism endowed with an elaborate protein O-glycosylation system that allows the bacterium to express a glycosylated surface (S)-layer comprising two high molecular weight glycoproteins modified with O-linked oligosaccharides. The T. forsythia S-layer has been implicated in the modulation of cytokine responses of antigen presenting cells, such as macrophages, that play a significant role during inflammation associated with periodontitis. The macrophage-inducible C-type lectin receptor (Mincle) is an FcRγ-coupled pathogen recognition receptor that recognizes a wide variety of sugar containing ligands from fungal and bacterial pathogens. In this study, we aimed to determine if Mincle might be involved in the recognition of T. forsythia S-layer and modulation of cytokine response of macrophages against the bacterium. Binding studies using recombinant Mincle-Fc fusion protein indicated a specific Ca2+-dependent binding of Mincle to T. forsythia S-layer. Subsequent experiments with Mincle-expressing and Mincle-knockdown macrophages revealed a role for Mincle/S-layer interaction in the induction of both pro- and anti-inflammatory cytokine secretion in macrophages stimulated with T. forsythia as well as its S-layer. Together, these studies revealed Mincle as an important macrophage receptor involved in the modulation of cytokine responses of macrophages against T. forsythia, and thus may play a critical role in orchestrating the host immune response against the bacterium. PMID:28264048

  16. Macrophage inducible C-type lectin (Mincle) recognizes glycosylated surface (S)-layer of the periodontal pathogen Tannerella forsythia.

    Science.gov (United States)

    Chinthamani, Sreedevi; Settem, Rajendra P; Honma, Kiyonobu; Kay, Jason G; Sharma, Ashu

    2017-01-01

    The oral pathogen Tannerella forsythia is implicated in the development of periodontitis, a common inflammatory disease that leads to the destruction of the gum and tooth supporting tissues, often leading to tooth loss. T. forsythia is a unique Gram-negative organism endowed with an elaborate protein O-glycosylation system that allows the bacterium to express a glycosylated surface (S)-layer comprising two high molecular weight glycoproteins modified with O-linked oligosaccharides. The T. forsythia S-layer has been implicated in the modulation of cytokine responses of antigen presenting cells, such as macrophages, that play a significant role during inflammation associated with periodontitis. The macrophage-inducible C-type lectin receptor (Mincle) is an FcRγ-coupled pathogen recognition receptor that recognizes a wide variety of sugar containing ligands from fungal and bacterial pathogens. In this study, we aimed to determine if Mincle might be involved in the recognition of T. forsythia S-layer and modulation of cytokine response of macrophages against the bacterium. Binding studies using recombinant Mincle-Fc fusion protein indicated a specific Ca2+-dependent binding of Mincle to T. forsythia S-layer. Subsequent experiments with Mincle-expressing and Mincle-knockdown macrophages revealed a role for Mincle/S-layer interaction in the induction of both pro- and anti-inflammatory cytokine secretion in macrophages stimulated with T. forsythia as well as its S-layer. Together, these studies revealed Mincle as an important macrophage receptor involved in the modulation of cytokine responses of macrophages against T. forsythia, and thus may play a critical role in orchestrating the host immune response against the bacterium.

  17. Specificity analysis of the C-type lectin from rattlesnake venom, and its selectivity towards Gal- or GalNAc-terminated glycoproteins.

    Science.gov (United States)

    Young, N Martin; van Faassen, Henk; Watson, David C; Mackenzie, C Roger

    2011-08-01

    The rattlesnake (Crotalus atrox) venom lectin is a readily-prepared decameric C-type lectin, specific for Gal and GalNAc. Glycan microarray analysis showed it reacted with a wide range of glycans, chiefly recognizing sets of compounds with Galβ1-4GlcNAc (LacNAc), α-Gal or α-GalNAc non-reducing termini. Its array profile was therefore distinctly different from those of four previously studied mammalian C-type lectins with the same Gal/GalNAc monosaccharide specificity, and it was more broadly reactive than several Gal- or GalNAc-specific plant lectins commonly used for glycan blotting. Though a general reactivity towards glycoproteins might be expected from the avidity conferred by its high valence, it showed a marked preference for glycoproteins with multiple glycans, terminated by Gal or GalNAc. Thus its ten closely-spaced sites each with a K(D) for GalNAc of ~2 mM appeared to make RSVL more selective than the four more widely-spaced sites of soybean agglutinin, with a ten-fold better K(D) for GalNAc.

  18. Super-resolution imaging of C-type lectin spatial rearrangement within the dendritic cell plasma membrane at fungal microbe contact sites

    Directory of Open Access Journals (Sweden)

    Michelle S Itano

    2014-08-01

    Full Text Available Dendritic cells express DC-SIGN and CD206, C-type lectins (CTLs that bind a variety of pathogens and may facilitate pathogen uptake for subsequent antigen presentation. Both proteins form punctate membrane nanodomains (~80 nm on naïve cells. We analyzed the spatiotemporal distribution of CTLs following host-fungal particle contact using confocal microscopy and three distinct methods of cluster identification and measurement of receptor clusters in super-resolution datasets: DBSCAN, Pair Correlation and a custom implementation of the Getis spatial statistic. Quantitative analysis of confocal and super-resolution images demonstrated that CTL nanodomains become concentrated in the contact site relative to non-contact membrane after the first hour of exposure and established that this recruitment is sustained out to four hours. DC-SIGN nanodomains in fungal contact sites exhibit a 70% area increase and a 38% decrease in interdomain separation. Contact site CD206 nanodomains possess 90% greater area and 42% lower interdomain separation relative to non-contact regions. Contact site CTL clusters appear as disk-shaped domains of approximately 150-175 nm in diameter. The increase in length scale of CTL nanostructure in contact sites suggests that the smaller nanodomains on resting membranes may merge during fungal nanodomain structure, or that they become packed closely enough to achieve sub-resolution inter-domain edge separations of < 30 nm. This study provides evidence of local receptor spatial rearrangements on the nanoscale that occur in the plasma membrane upon pathogen binding and may direct important signaling interactions required to recognize and respond to the presence of a relatively large pathogen.

  19. A platform to screen for C-type lectin receptor-binding carbohydrates and their potential for cell-specific targeting and immune modulation.

    Science.gov (United States)

    Maglinao, Maha; Eriksson, Magdalena; Schlegel, Mark K; Zimmermann, Stephanie; Johannssen, Timo; Götze, Sebastian; Seeberger, Peter H; Lepenies, Bernd

    2014-02-10

    Myeloid C-type lectin receptors (CLRs) in innate immunity represent a superfamily of pattern recognition receptors that recognize carbohydrate structures on pathogens and self-antigens. The primary interaction of an antigen-presenting cell and a pathogen shapes the following immune response. Therefore, the identification of CLR ligands that can either enhance or modulate the immune response is of interest. We have developed a screening platform based on glycan arrays to identify immune modulatory carbohydrate ligands of CLRs. A comprehensive library of CLRs was expressed by fusing the extracellular part of each respective CLR, the part containing the carbohydrate-recognition domain (CRD), to the Fc fragment of human IgG1 molecules. CLR-Fc fusion proteins display the CRD in a dimeric form, are properly glycosylated, and can be detected by a secondary antibody with a conjugated fluorophore. Thus, they are valuable tools for high-throughput screening. We were able to identify novel carbohydrate binders of CLRs using the glycan array technology. These CLR-binding carbohydrates were then covalently attached to the model antigen ovalbumin. The ovalbumin neoglycoconjugates were used in a dendritic cell/T cell co-culture assay to stimulate transgenic T cells in vitro. In addition, mice were immunized with these conjugates to analyze the immune modulatory properties of the CLR ligands in vivo. The CLR ligands induced an increased Th1 cytokine production in vitro and modulated the humoral response in vivo. The platform described here allows for the identification of CLR ligands, as well as the evaluation of each ligand's cell-specific targeting and immune modulatory properties.

  20. A single-CRD C-type lectin from oyster Crassostrea gigas mediates immune recognition and pathogen elimination with a potential role in the activation of complement system.

    Science.gov (United States)

    Li, Hui; Zhang, Huan; Jiang, Shuai; Wang, Weilin; Xin, Lusheng; Wang, Hao; Wang, Lingling; Song, Linsheng

    2015-06-01

    C-type lectins (CTLs), serving as pattern recognition receptors (PRRs), are a superfamily of Ca(2+)-dependent carbohydrate-recognition proteins that participate in nonself-recognition and pathogen elimination. In the present study, a single carbohydrate-recognition domain (CRD) CTL was identified from oyster Crassostrea gigas (designated as CgCLec-2). There was only one CRD within the deduced amino acid sequence of CgCLec-2 consisting of 129 amino acid residues. A conserved EPN (Glu246-Pro247-Asn248) motif was found in Ca(2+)-binding site 2 of CgCLec-2. The CgCLec-2 mRNA could be detected in all the examined tissues at different expression levels in oysters. The mRNA expression of CgCLec-2 in hemocytes was up-regulated significantly at 6 h post Vibrio splendidus challenge. The recombinant CgCLec-2 (rCgCLec-2) could bind various Pathogen-Associated Molecular Patterns (PAMPs), including lipopolysaccharide, mannan and peptidoglycan, and displayed strong binding abilities to Vibrio anguillarum, V. splendidus and Yarrowiali polytica and week binding ability to Staphylococcus aureus. It could also enhance the phagocytic activity of oyster hemocytes to V. splendidus and exhibited growth suppression activity against gram-positive bacteria S. aureus but no effect on gram-negative bacteria V. splendidus. Furthermore, the interaction between rCgCLec-2 and rCgMASPL-1 was confirmed by GST Pull down. The results suggested that CgCLec-2 served as not only a PRR in immune recognition but also a regulatory factor in pathogen elimination, and played a potential role in the activation of complement system.

  1. Diversity of lectins in Macrobrachium rosenbergii and their expression patterns under spiroplasma MR-1008 stimulation.

    Science.gov (United States)

    Zhu, Huanxi; Du, Jie; Hui, Kai-Min; Liu, Peng; Chen, Jing; Xiu, Yunji; Yao, Wei; Wu, Ting; Meng, Qingguo; Gu, Wei; Ren, Qian; Wang, Wen

    2013-08-01

    Lectins play important roles in crustacean innate immunity through recognition of foreign pathogens. In this study, 20 lectins including C-type lectins [dual-carbohydrate recognition domain (CRD) type and single-CRD type], L-type lectin, and lectin with low-density lipoprotein class A (LDLa) domain were identified from the freshwater prawn Macrobrachium rosenbergii. The tissue distribution and expression patterns of these lectins under spiroplasma strain MR-1008 challenge were investigated. Most of the lectins were found to be mainly distributed in the hepatopancreas. Lectin5, Lectin14, Lectin17, and Lectin18 exhibited the highest expression level in the hemocytes, nerve, intestine, and heart, respectively. MrLec1 to MrLec6 (dual-CRD lectins) in the hepatopancreas were up-regulated by spiroplasma challenge. Single-CRD lectins reached the highest level at 72 h after spiroplasma challenge. Lectin9 and Lectin15 both belong to L-type lectins. At post-spiroplasma challenge, Lectin9 expression was up-regulated, whereas Lectin15 expression was down-regulated. Lectin11 with LDLa domain showed the highest level after 12 h Lectin18 and Lectin20, namely, CD209, were also up-regulated by spiroplasma challenge. Lectin14, a C-type lectin, quickly reached the highest level after 2 h Lectin16 showed the highest level after 72 h Lectin5 reached the highest level in cultured hemocytes after 6 h Lectin17 in the intestine and Lectin14 in the nerve were slightly up-regulated after 6 and 2 h, respectively. Our research results indicate that lectins may play important roles in early or late immune responses against spiroplasma challenge.

  2. 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...

  3. Evolution of the C-Type Lectin-Like Receptor Genes of the DECTIN-1 Cluster in the NK Gene Complex

    Directory of Open Access Journals (Sweden)

    Susanne Sattler

    2012-01-01

    Full Text Available Pattern recognition receptors are crucial in initiating and shaping innate and adaptive immune responses and often belong to families of structurally and evolutionarily related proteins. The human C-type lectin-like receptors encoded in the DECTIN-1 cluster within the NK gene complex contain prominent receptors with pattern recognition function, such as DECTIN-1 and LOX-1. All members of this cluster share significant homology and are considered to have arisen from subsequent gene duplications. Recent developments in sequencing and the availability of comprehensive sequence data comprising many species showed that the receptors of the DECTIN-1 cluster are not only homologous to each other but also highly conserved between species. Even in Caenorhabditis elegans, genes displaying homology to the mammalian C-type lectin-like receptors have been detected. In this paper, we conduct a comprehensive phylogenetic survey and give an up-to-date overview of the currently available data on the evolutionary emergence of the DECTIN-1 cluster genes.

  4. Lectin domains of polypeptide GalNAc transferases exhibit glycopeptide binding specificity.

    Science.gov (United States)

    Pedersen, Johannes W; Bennett, Eric P; Schjoldager, Katrine T-B G; Meldal, Morten; Holmér, Andreas P; Blixt, Ola; Cló, Emiliano; Levery, Steven B; Clausen, Henrik; Wandall, Hans H

    2011-09-16

    UDP-GalNAc:polypeptide α-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 specificity, whereas the primary function of the lectin domain is to increase affinity to previously glycosylated substrates. Whether the lectin domain also has peptide sequence selectivity has remained unclear. Using a glycopeptide array with a library of synthetic and recombinant glycopeptides based 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 an additional level of complexity in the initiation step of O-glycosylation by GalNAc-Ts.

  5. Regulation of adherence and virulence by the Entamoeba histolytica lectin cytoplasmic domain, which contains a beta2 integrin motif.

    Science.gov (United States)

    Vines, R R; Ramakrishnan, G; Rogers, J B; Lockhart, L A; Mann, B J; Petri, W A

    1998-08-01

    Killing of human cells by the parasite Entamoeba histolytica requires adherence via an amebic cell surface lectin. Lectin activity in the parasite is regulated by inside-out signaling. The lectin cytoplasmic domain has sequence identity with a region of the beta2 integrin cytoplasmic tail implicated in regulation of integrin-mediated adhesion. Intracellular expression of a fusion protein containing the cytoplasmic domain of the lectin has a dominant negative effect on extracellular lectin-mediated cell adherence. Mutation of the integrin-like sequence abrogates the dominant negative effect. Amebae expressing the dominant negative mutant are less virulent in an animal model of amebiasis. These results suggest that inside-out signaling via the lectin cytoplasmic domain may control the extracellular adhesive activity of the amebic lectin and provide in vivo demonstration of the lectin's role in virulence.

  6. Involvement of viral envelope GP2 in Ebola virus entry into cells expressing the macrophage galactose-type C-type lectin

    Energy Technology Data Exchange (ETDEWEB)

    Usami, Katsuaki [Laboratory of Cancer Biology and Molecular Immunology, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033 (Japan); Matsuno, Keita; Igarashi, Manabu [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo 001-0020 (Japan); Denda-Nagai, Kaori [Laboratory of Cancer Biology and Molecular Immunology, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033 (Japan); Takada, Ayato [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo 001-0020 (Japan); Irimura, Tatsuro, E-mail: irimura@mol.f.u-tokyo.ac.jp [Laboratory of Cancer Biology and Molecular Immunology, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033 (Japan)

    2011-04-01

    Highlights: {yields} Ebola virus infection is mediated by binding to and fusion with the target cells. {yields} Structural feature of the viral glycoprotein determines the infectivity. {yields} Surface C-type lectin, MGL, of macrophages and dendritic cells mediate the infection. {yields} GP2, one of glycoprotein subunits, plays an essential role in MGL-mediated infection. {yields} There is a critical amino acid residue involved in high infectivity. -- Abstract: Ebola virus (EBOV) infection is initiated by the interaction of the viral surface envelope glycoprotein (GP) with the binding sites on target cells. Differences in the mortality among different species of the Ebola viruses, i.e., Zaire ebolavirus (ZEBOV) and Reston ebolavirus (REBOV), correspond to the in vitro infectivity of the pseudo-typed virus constructed with the GPs in cells expressing macrophage galactose-type calcium-type lectin (MGL/CD301). Through mutagenesis of GP2, the transmembrane-anchored subunit of GP, we found that residues 502-527 of the GP2 sequence determined the different infectivity between VSV-ZEBOV GP and -REBOV GP in MGL/CD301-expressing cells and a histidine residue at position 516 of ZEBOV GP2 appeared essential in the differential infectivity. These findings may provide a clue to clarify a molecular basis of different pathogenicity among EBOV species.

  7. CLEC4F is an inducible C-type lectin in F4/80-positive cells and is involved in alpha-galactosylceramide presentation in liver.

    Directory of Open Access Journals (Sweden)

    Chih-Ya Yang

    Full Text Available CLEC4F, a member of C-type lectin, was first purified from rat liver extract with high binding affinity to fucose, galactose (Gal, N-acetylgalactosamine (GalNAc, and un-sialylated glucosphingolipids with GalNAc or Gal terminus. However, the biological functions of CLEC4F have not been elucidated. To address this question, we examined the expression and distribution of murine CLEC4F, determined its binding specificity by glycan array, and investigated its function using CLEC4F knockout (Clec4f-/- mice. We found that CLEC4F is a heavily glycosylated membrane protein co-expressed with F4/80 on Kupffer cells. In contrast to F4/80, CLEC4F is detectable in fetal livers at embryonic day 11.5 (E11.5 but not in yolk sac, suggesting the expression of CLEC4F is induced as cells migrate from yolk cells to the liver. Even though CLEC4F is not detectable in tissues outside liver, both residential Kupffer cells and infiltrating mononuclear cells surrounding liver abscesses are CLEC4F-positive upon Listeria monocytogenes (L. monocytogenes infection. While CLEC4F has strong binding to Gal and GalNAc, terminal fucosylation inhibits CLEC4F recognition to several glycans such as Fucosyl GM1, Globo H, Bb3∼4 and other fucosyl-glycans. Moreover, CLEC4F interacts with alpha-galactosylceramide (α-GalCer in a calcium-dependent manner and participates in the presentation of α-GalCer to natural killer T (NKT cells. This suggests that CLEC4F is a C-type lectin with diverse binding specificity expressed on residential Kupffer cells and infiltrating monocytes in the liver, and may play an important role to modulate glycolipids presentation on Kupffer cells.

  8. Mutational analysis of affinity and selectivity of kringle-tetranectin interaction. Grafting novel kringle affinity ontp the trtranectin lectin scaffold

    DEFF Research Database (Denmark)

    Graversen, Jonas Heilskov; Jacobsen, C; Sigurskjold, B W

    2000-01-01

    C-type lectin-like domains are found in many proteins, where they mediate binding to a wide diversity of compounds, including carbohydrates, lipids, and proteins. The binding of a C-type lectin-like domain to a ligand is often influenced by calcium. Recently, we have identified a site in the C-ty...

  9. The Mycobacterium tuberculosis cell-surface glycoprotein apa as a potential adhesin to colonize target cells via the innate immune system pulmonary C-type lectin surfactant protein A.

    Science.gov (United States)

    Ragas, Aude; Roussel, Lucie; Puzo, Germain; Rivière, Michel

    2007-02-23

    Tuberculosis is still a major health problem, and understanding the mechanism by which Mycobacterium tuberculosis (Mtb) invades and colonizes its host target cells remains an important issue for the control of infection. The innate immune system C-type lectins (C-TLs), including the human pulmonary surfactant protein A (PSP-A), have been recently identified as determinant players in the early recognition of the invading pathogen and in mounting the host defense response. Although the antigenic lipoglycan mannosylated lipoarabinomannan is currently considered to be the major C-TL target on the mycobacterial surface, the recognition by some C-TLs of the only mycobacterial species composing the "Mtb complex" indicates that mannosylated lipoarabinomannan cannot account alone for this specificity. Thus, we searched for the mycobacterial molecules targeted by human PSP-A, focusing our attention on the Mtb surface glycoproteins. We developed an original functional proteomic approach based on a lectin blot assay using crude human bronchoalveolar lavage fluid as a source of physiological PSP-A. Combined with selective cell-surface protein extraction and mass spectrometry peptide mapping, this strategy allowed us to identify the Apa (alanine- and proline-rich antigenic) glycoprotein as new potential target for PSP-A. This result was supported by direct binding of PSP-A to purified Apa. Moreover, EDTA addition or deglycosylation of purified Apa samples completely abolished the interaction, demonstrating that the interaction is calcium- and mannose-dependent, as expected. Finally, we provide convincing evidence that Apa, formerly considered as mainly secreted, is associated with the cell wall for a sufficiently long time to aid in the attachment of PSP-A. Because, to date, Apa seems to be restricted to the Mtb complex strains, we propose that it may account for the selective recognition of those strains by PSP-A and other immune system C-TLs containing homologous functional

  10. C-type lectin receptors Dectin-3 and Dectin-2 form a heterodimeric pattern-recognition receptor for host defense against fungal infection.

    Science.gov (United States)

    Zhu, Le-Le; Zhao, Xue-Qiang; Jiang, Changying; You, Yun; Chen, Xiao-Ping; Jiang, Yuan-Ying; Jia, Xin-Ming; Lin, Xin

    2013-08-22

    C-type lectin receptors (CLRs) play critical roles as pattern-recognition receptors (PRRs) for sensing Candida albicans infection, which can be life-threatening for immunocompromised individuals. Here we have shown that Dectin-3 (also called CLECSF8, MCL, or Clec4d), a previously uncharacterized CLR, recognized α-mannans on the surfaces of C. albicans hyphae and induced NF-κB activation. Mice with either blockade or genetically deleted Dectin-3 were highly susceptible to C. albicans infection. Dectin-3 constantly formed heterodimers with Dectin-2, a well-characterized CLR, for recognizing C. albicans hyphae. Compared to their respective homodimers, Dectin-3 and Dectin-2 heterodimers bound α-mannans more effectively, leading to potent inflammatory responses against fungal infections. Together, our study demonstrates that Dectin-3 forms a heterodimeric PRR with Dectin-2 for sensing fungal infection and suggests that different CLRs may form different hetero- and homodimers, which provide different sensitivity and diversity for host cells to detect various microbial infections.

  11. The C-type lectin receptor SIGNR3 binds to fungi present in commensal microbiota and influences immune regulation in experimental colitis

    Directory of Open Access Journals (Sweden)

    Magdalena eEriksson

    2013-07-01

    Full Text Available Inflammatory bowel disease is a condition of acute and chronic inflammation of the gut. An important factor contributing to pathogenesis is a dysregulated mucosal immunity against commensal bacteria and fungi. Host pattern recognition receptors sense commensals in the gut and are involved in maintaining the balance between controlled responses to pathogens and overwhelming innate immune activation. C-type lectin receptors (CLRs are pattern recognition receptors recognizing glycan structures on pathogens and self-antigens. Here we examined the role of the murine CLR SIGNR3 in the recognition of commensals and its involvement in intestinal immunity. SIGNR3 is the closest murine homologue of the human DC-SIGN receptor recognizing similar carbohydrate ligands such as terminal fucose or high-mannose glycans. We discovered that SIGNR3 recognizes fungi present in the commensal microbiota. To analyze if this interaction impacts the intestinal immunity against microbiota, the dextran sulfate sodium (DSS-induced colitis model was employed. SIGNR3-/- mice exhibited an increased weight loss associated with more severe colitis symptoms compared to wild-type control mice. The increased inflammation in SIGNR3-/- mice was accompanied by a higher level of TNF-α in colon. Our findings demonstrate for the first time that SIGNR3 recognizes intestinal fungi and has an immune regulatory role in colitis.

  12. Vixapatin (VP12, a C-Type Lectin-Protein from Vipera xantina palestinae Venom: Characterization as a Novel Anti-angiogenic Compound

    Directory of Open Access Journals (Sweden)

    Philip Lazarovici

    2012-10-01

    Full Text Available A C-type lectin-like protein (CTL, originally identified as VP12 and lately named Vixapatin, was isolated and characterized from Israeli viper Vipera xantina palestinae snake venom. This CTL was characterized as a selective α2β1 integrin inhibitor with anti-melanoma metastatic activity. The major aim of the present study was to prove the possibility that this protein is also a potent novel anti-angiogenic compound. Using an adhesion assay, we demonstrated that Vixapatin selectively and potently inhibited the α2 mediated adhesion of K562 over-expressing cells, with IC50 of 3 nM. 3 nM Vixapatin blocked proliferation of human dermal microvascular endothelial cells (HDMEC; 25 nM inhibited collagen I induced migration of human fibrosarcoma HT-1080 cells; and 50 nM rat C6 glioma and human breast carcinoma MDA-MB-231 cells. 1 µM Vixapatin reduced HDMEC tube formation by 75% in a Matrigel assay. Furthermore, 1 µM Vixapatin decreased by 70% bFGF-induced physiological angiogenesis, and by 94% C6 glioma-induced pathological angiogenesis, in shell-less embryonic quail chorioallantoic membrane assay. Vixapatin’s ability to inhibit all steps of the angiogenesis process suggest that it is a novel pharmacological tool for studying α2β1 integrin mediated angiogenesis and a lead compound for the development of a novel anti-angiogenic/angiostatic/anti-cancer drug.

  13. Extrinsic functions of lectin domains in O-N-acetylgalactosamine glycan biosynthesis

    DEFF Research Database (Denmark)

    Lorenz, Virginia; Ditamo, Yanina; Cejas, Romina B;

    2016-01-01

    Glycan biosynthesis occurs mainly in Golgi. Molecular organization and functional regulation of this process are not well understood. We evaluated the extrinsic effect of lectin domains (β-trefoil fold) of polypeptide GalNAc-transferases (ppGalNAc-Ts) on catalytic activity of glycosyltransferases...

  14. Macrophage-inducible C-type lectin is associated with anti-cyclic citrullinated peptide antibodies-positive rheumatoid arthritis in men

    Institute of Scientific and Technical Information of China (English)

    WU Xin-yu; GUO Jian-ping; YIN Fang-rui; LU Xiao-lan; LI Ru; HE Jing; LIU Xu; LI Zhan-guo

    2012-01-01

    Background Macrophage-inducible C-type lectin (MINCLE) is an important member of C-type lectin superfamily,which has been shown evidence for susceptibility to arthritis in animal models.We aimed to investigate the possible association of MINCLE with rheumatoid arthritis (RA) susceptibility in Chinese Hart population.Methods Haplotypes from HapMap database (Chinese Hart Beijing,CHB) were used to select tag-single nucleotide polymorphism (SNP) (r2=0.8) residing in MINCLE gene.A total of 563 patients with RA and 404 healthy controls were TagMan genotyped for SNP rs10841845.Association analyses were performed on the whole data set and on RA subsets based on gender difference and the status of anti-cyclic citrullinated peptide (anti-CCP) antibody in RA patients.Association statistics were calculated by age and sex adjusted logistic regression.Results Overall,MINCLE SNP rs10841845 was not associated with susceptibility to RA.However,following anti-CCP stratification,rs10841845 GG genotypes conferred a significantly protective effects against anti-CCP-positive RA (OR 0.65,95% CI 0.430-0.995,P=0.048).Following gender stratification,SNP rs10841845 G allele appeared to insert its RA protective effect only in male patients,both at allele level (G vs.A OR 0.66,95% CI 0.46-0.93,P=0.018) and at genotype level (GG vs.AA+AG,OR 0.429,95% CI 0.20-0.95,P=0.036).Notably,the male RA protective effect of rs10841845 G allele was only seen in anti-CCP-positive RA (G vs.A:OR 0.64,95% CI 0.43-0.96,P=0.029; GG vs.AA+AG:OR 0.375,95% Cl 0.14-0.94,P=0.038).Furthermore,we observed a significant reduction of Disease Activity Score (DAS) 28 score (3.91±0.70 vs.5.66±0.31,P=0.022) and serum C-reactive protein levels (31.64±24.13 vs.91.80±12.02,P=0.012)in male anti-CCP-positive RA patients carrying rs10841845 GG genotype,compared with patients carrying AA+AG genotypes.Conclusions Our study provides the evidence for a gender specific association between MINCLE rs10841845 and RA

  15. A novel C-type lectin, Nattectin-like protein, with a wide range of bacterial agglutination activity in large yellow croaker Larimichthys crocea.

    Science.gov (United States)

    Lv, Changhuan; Zhang, Dongling; Wang, Zhiyong

    2016-03-01

    C-type lectins (CTLs) are generally recognized as a superfamily of Ca(2+)-dependent carbohydrate-binding proteins, which serve as pattern recognition receptors (PRRs) in innate immunity of vertebrates. In this study, the molecular characterization and immune roles of a novel CTL from Larimichthys crocea (designated as LcNTC) were investigated. LcNTC is a novel protein that shared 33%-49% homology with other teleosts CTLs. The full-length cDNA of LcNTC was composed of 859 bp with a 465 bp open reading frame encoding a putative protein of 154 residues. LcNTC contained a single CRD with four conserved disulfide-bonded cysteine residues (Cys(57)-Cys(148), Cys(126)-Cys(140)) and EPN/AND motifs instead of invariant EPN/WND motifs required for carbohydrate-binding specificity and constructing Ca(2+)-binding sites. LcNTC mRNA was detected in all examined tissues with the most abundant in the gill. After challenged with poly I:C and Vibrio parahaemolyticus, the temporal expression of LcNTC was significantly up-regulated in the liver, spleen and head-kidney. LcNTC transcripts were also induced in the gill, skin, spleen and head-kidney post-infection with Cryptocaryon irritans. The recombinant LcNTC (rLcNTC) purified from Escherichia coli BL21 (DE3) exhibited strong agglutination activity against erythrocytes from human, rabbit and large yellow croaker in a Ca(2+)-dependent manner, and the agglutination could be inhibited by D-Mannose, D-Glucose, D-Fructose, α-Lactose, D-Maltose and LPS. Positive microbial agglutination activities of rLcNTC were observed against all tested bacteria in the presence of Ca(2+), including Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus and Micrococcus lysoleikticus) and Gram-negative bacteria (E. coli, V. parahaemolyticus, Vibrio alginolyticus and Aeromonas hydrophila). These findings collectively indicated that LcNTC might be involved in the innate immunity of L. crocea as a PRR.

  16. 栉孔扇贝C型凝集素基因的cDNA克隆和序列分析%cDNA Cloning and Sequence Analysis on C -Type Lectin gene of Chlamys farreri

    Institute of Scientific and Technical Information of China (English)

    黄海宁

    2006-01-01

    利用本实验室已建立的栉孔扇贝cDNA文库中已知表达序列标签(expression sequence tag,EST),采用cDNA末端快速扩增(rapid amplification of cDNA end,RACE)技术获得目的基因的cDNA编码全序列.利用BLAST比对分析,结果发现目的基因序列与日本鳗鲡(Anguilla japonica)C型凝集素(C-type Lectin)E值达4e-19;利用Clustalw软件将目的基因与脊椎动物和节肢动物C型凝集素的多序列比对,发现克隆片段具有C型凝集素家族的标签序列模式且有很高的同源性,在该序列中形成二硫键的4个保守的半胱氨酸,与其他物种C型凝集素的二硫键结构非常相似;同时发现在其成熟肽中含有糖识别域(carbohydrate recognition domain,CRD),且Cys的位点是保守的.分析结果表明我们克隆的目的基因极可能为栉孔扇贝(Chlamys farreri)的C型凝集素基因.

  17. Lectins with Anti-HIV Activity: A Review

    Directory of Open Access Journals (Sweden)

    Ouafae Akkouh

    2015-01-01

    Full Text Available Lectins including flowering plant lectins, algal lectins, cyanobacterial lectins, actinomycete lectin, worm lectins, and the nonpeptidic lectin mimics pradimicins and benanomicins, exhibit anti-HIV activity. The anti-HIV plant lectins include Artocarpus heterophyllus (jacalin lectin, concanavalin A, Galanthus nivalis (snowdrop agglutinin-related lectins, Musa acuminata (banana lectin, Myrianthus holstii lectin, Narcissus pseudonarcissus lectin, and Urtica diocia agglutinin. The anti-HIV algal lectins comprise Boodlea coacta lectin, Griffithsin, Oscillatoria agardhii agglutinin. The anti-HIV cyanobacterial lectins are cyanovirin-N, scytovirin, Microcystis viridis lectin, and microvirin. Actinohivin is an anti-HIV actinomycete lectin. The anti-HIV worm lectins include Chaetopterus variopedatus polychaete marine worm lectin, Serpula vermicularis sea worm lectin, and C-type lectin Mermaid from nematode (Laxus oneistus. The anti-HIV nonpeptidic lectin mimics comprise pradimicins and benanomicins. Their anti-HIV mechanisms are discussed.

  18. Dynamic interplay between catalytic and lectin domains of GalNAc-transferases modulates protein O-glycosylation

    DEFF Research Database (Denmark)

    Lira-Navarrete, Erandi; de Las Rivas, Matilde; Compañón, Ismael;

    2015-01-01

    Protein O-glycosylation is controlled by polypeptide GalNAc-transferases (GalNAc-Ts) that uniquely feature both a catalytic and lectin domain. The underlying molecular basis of how the lectin domains of GalNAc-Ts contribute to glycopeptide specificity and catalysis remains unclear. Here we present...... the first crystal structures of complexes of GalNAc-T2 with glycopeptides that together with enhanced sampling molecular dynamics simulations demonstrate a cooperative mechanism by which the lectin domain enables free acceptor sites binding of glycopeptides into the catalytic domain. Atomic force microscopy...... and small-angle X-ray scattering experiments further reveal a dynamic conformational landscape of GalNAc-T2 and a prominent role of compact structures that are both required for efficient catalysis. Our model indicates that the activity profile of GalNAc-T2 is dictated by conformational heterogeneity...

  19. Phylogenetic and specificity studies of two-domain GNA-related lectins: generation of multispecificity through domain duplication and divergent evolution.

    Science.gov (United States)

    Van Damme, Els J M; Nakamura-Tsuruta, Sachiko; Smith, David F; Ongenaert, Maté; Winter, Harry C; Rougé, Pierre; Goldstein, Irwin J; Mo, Hanqing; Kominami, Junko; Culerrier, Raphaël; Barre, Annick; Hirabayashi, Jun; Peumans, Willy J

    2007-05-15

    A re-investigation of the occurrence and taxonomic distribution of proteins built up of protomers consisting of two tandem arrayed domains equivalent to the GNA [Galanthus nivalis (snowdrop) agglutinin] revealed that these are widespread among monotyledonous plants. Phylogenetic analysis of the available sequences indicated that these proteins do not represent a monophylogenetic group but most probably result from multiple independent domain duplication/in tandem insertion events. To corroborate the relationship between inter-domain sequence divergence and the widening of specificity range, a detailed comparative analysis was made of the sequences and specificity of a set of two-domain GNA-related lectins. Glycan microarray analyses, frontal affinity chromatography and surface plasmon resonance measurements demonstrated that the two-domain GNA-related lectins acquired a marked diversity in carbohydrate-binding specificity that strikingly contrasts the canonical exclusive specificity of their single domain counterparts towards mannose. Moreover, it appears that most two-domain GNA-related lectins interact with both high mannose and complex N-glycans and that this dual specificity relies on the simultaneous presence of at least two different independently acting binding sites. The combined phylogenetic, specificity and structural data strongly suggest that plants used domain duplication followed by divergent evolution as a mechanism to generate multispecific lectins from a single mannose-binding domain. Taking into account that the shift in specificity of some binding sites from high mannose to complex type N-glycans implies that the two-domain GNA-related lectins are primarily directed against typical animal glycans, it is tempting to speculate that plants developed two-domain GNA-related lectins for defence purposes.

  20. An evaluation of garlic lectin as an alternative carrier domain for insecticidal fusion proteins

    Institute of Scientific and Technical Information of China (English)

    Elaine Fitches; Judith Philip; Gareth Hinchliffe; Leisbeth Vercruysse; Nanasaheb Chougule; John A.Gatehouse

    2008-01-01

    The mannosc-binding lectin GNA(snowdrop lectin)is used as a"carrier"domain in insecticidal fusion proteins which cross the insect gut after oral ingestion.A similar lectin from garlic bulb,ASAII,has been evaluated as an altemative"carrieff".Recombinant ASAII delivered orally to larvae of cabbage moth(Mamestra brassica;Lepidoptera)Was subse-quently detected in haemolymph,demonstrating transport.Fusion proteins comprising an insect neurotoxin.ButaIT(Buthus tamulus insecticidal toxin;red scorpion toxin)linked to the C-terminal region of ASAII or GNA were produced as recombinant proteins(GNA/ButaIT and ASA/ButaIT)by expression in Pichia pastoris.In both cases the C-terminal sequence of the lectin was truncated to avoid post-translational proteolysis.The GNA-containing fusion protein was toxic by injection to cabbage moth larvae(LD50≈250μg/g),and when fed had a negative effect on survival and growth.It also decreased the survival of cereal aphids(Sitobion avenae;Homoptera)from neonate to adult by>70%when fed.In contrast,the ASA-ButaIT fusion protein was non-toxic to aphids,and had no effect on lepidopteran lalwae,either when injected or when fed.However,intact ASA-ButaIT fusion protein was present in the haemolymph of cabbage moth larvae following ingestion,showing that transport of the fusion had occurred.The stabilities of GNA/BUtaIT and ASA/ButaIT to proteolysis in vivo after injection or ingestion differed,and this may be a factor in determining insecticidal activities.

  1. Carbohydrate recognition factors of the lectin domains present in the Ricinus communis toxic protein (ricin).

    Science.gov (United States)

    Wu, June H; Singh, Tanuja; Herp, Anthony; Wu, Albert M

    2006-02-01

    Ricin (RCA60) is a potent cytotoxic protein with lectin domains, contained in the seeds of the castor bean Ricinus communis. It is a potential biohazard. To corroborate the biological properties of ricin, it is essential to understand the recognition factors involved in the ricin-glycotope interaction. In previous reports, knowledge of the binding properties of ricin was limited to oligosugars and glycopeptides with different specificities. Here, recognition factors of the lectin domains in ricin were examined by enzyme-linked lectinosorbent (ELLSA) and inhibition assays, using mammalian Gal/GalNAc structural units and corresponding polyvalent forms. Except for blood group GalNAcalpha1-3Gal (A) active and Forssman (GalNAcalpha1-3GalNAc, F) disaccharides, ricin has a broad range of affinity for mammalian disaccharide structural units-Galbeta1-4Glcbeta1-(Lbeta), Galbeta1-4GlcNAc (II), Galbeta1-3GlcNAc (I), Galbeta1-3GalNAcalpha1-(Talpha), Galbeta1-3GalNAcbeta1-(Tbeta), Galalpha1-3Gal (B), Galalpha1-4Gal (E), GalNAcbeta1-3Gal (P), GalNAcalpha1-Ser/Thr (Tn) and GalNAcbeta1-4Gal (S). Among the polyvalent glycotopes tested, ricin reacted best with type II-containing glycoproteins (gps). It also reacted well with several T (Thomsen-Friedenreich), tumor-associated Tn and blood group Sd. (a+)-containing gps. Except for bird nest and Tamm-Horsfall gps (THGP), this lectin reacted weakly or not at all with ABH-blood type and sialylated gps. From the present and previous results, it can be concluded that: (i) the combining sites of these lectin domains should be a shallow-groove type, recognizing Galbeta1-4Glcbeta1- and Galbeta1-3(4)GlcNAcbeta- as the major binding site; (ii) its size may be as large as a tetrasaccharide and most complementary to lacto-N-tetraose (Galbeta1-3GlcNAc beta1-3Galbeta1-4Glc) and lacto-N-neotetraose (Galbeta1-4GlcNAcbeta1-3Galbeta1-4Glc); (iii) the polyvalency of glycotopes, in general, enhances binding; (iv) a hydrophobic interaction in the vicinity

  2. Structural characterisation of the native fetuin-binding protein Scilla campanulata agglutinin: a novel two-domain lectin.

    Science.gov (United States)

    Wright, L M; Reynolds, C D; Rizkallah, P J; Allen, A K; Van Damme, E J; Donovan, M J; Peumans, W J

    2000-02-18

    The three-dimensional structure of a 244-residue, multivalent, fetuin-binding lectin, SCAfet, isolated from bluebell (Scilla campanulata) bulbs, has been solved at 3.3 A resolution by molecular replacement using the coordinates of the 119-residue, mannose-binding lectin, SCAman, also from bluebell bulbs. Unlike most monocot mannose-binding lectins, such as Galanthus nivalis agglutinin from snowdrop bulbs, which fold into a single domain, SCAfet contains two domains with approximately 55% sequence identity, joined by a linker peptide. Both domains are made up of a 12-stranded beta-prism II fold, with three putative carbohydrate-binding sites, one on each subdomain. SCAfet binds to the complex saccharides of various animal glycoproteins but not to simple sugars.

  3. The lectin domains of polypeptide GalNAc-transferases exhibit carbohydrate-binding specificity for GalNAc: lectin binding to GalNAc-glycopeptide substrates is required for high density GalNAc-O-glycosylation

    DEFF Research Database (Denmark)

    Wandall, Hans H; Irazoqui, Fernando; Tarp, Mads Agervig;

    2007-01-01

    to the enzyme. We have previously shown that the lectin domain of GalNAc-T4 modulates its substrate specificity to enable unique GalNAc-glycopeptide specificities and that this effect is selectively inhibitable by GalNAc; however, direct evidence of carbohydrate binding of GalNAc-transferase lectins has......-T2). Both lectins exhibited specificity for binding of free GalNAc. Kinetic and time-course analysis of GalNAc-T2 demonstrated that the lectin domain did not affect transfer to initial glycosylation sites, but selectively modulated velocity of transfer to subsequent sites and affected the number......Initiation of mucin-type O-glycosylation is controlled by a large family of UDP GalNAc:polypeptide N-acetylgalactosaminyltransferases (GalNAc-transferases). Most GalNAc-transferases contain a ricin-like lectin domain in the C-terminal end, which may confer GalNAc-glycopeptide substrate specificity...

  4. Dynamic interplay between catalytic and lectin domains of GalNAc-transferases modulates protein O-glycosylation

    Science.gov (United States)

    Lira-Navarrete, Erandi; de Las Rivas, Matilde; Compañón, Ismael; Pallarés, María Carmen; Kong, Yun; Iglesias-Fernández, Javier; Bernardes, Gonçalo J. L.; Peregrina, Jesús M.; Rovira, Carme; Bernadó, Pau; Bruscolini, Pierpaolo; Clausen, Henrik; Lostao, Anabel; Corzana, Francisco; Hurtado-Guerrero, Ramon

    2015-05-01

    Protein O-glycosylation is controlled by polypeptide GalNAc-transferases (GalNAc-Ts) that uniquely feature both a catalytic and lectin domain. The underlying molecular basis of how the lectin domains of GalNAc-Ts contribute to glycopeptide specificity and catalysis remains unclear. Here we present the first crystal structures of complexes of GalNAc-T2 with glycopeptides that together with enhanced sampling molecular dynamics simulations demonstrate a cooperative mechanism by which the lectin domain enables free acceptor sites binding of glycopeptides into the catalytic domain. Atomic force microscopy and small-angle X-ray scattering experiments further reveal a dynamic conformational landscape of GalNAc-T2 and a prominent role of compact structures that are both required for efficient catalysis. Our model indicates that the activity profile of GalNAc-T2 is dictated by conformational heterogeneity and relies on a flexible linker located between the catalytic and the lectin domains. Our results also shed light on how GalNAc-Ts generate dense decoration of proteins with O-glycans.

  5. Structure and Specificity of a Binary Tandem Domain F-Lectin from Striped Bass (Morone saxatilis)

    Energy Technology Data Exchange (ETDEWEB)

    Bianchet, M.; Odom, E; Vasta, J; Amzel, M

    2010-01-01

    The plasma of the striped bass Morone saxatilis contains a fucose-specific lectin (MsaFBP32) that consists of two F-type carbohydrate recognition domains (CRDs) in tandem. The crystal structure of the complex of MsaFBP32 with l-fucose reported here shows a cylindrical 81-A-long and 60-A-wide trimer divided into two globular halves: one containing N-terminal CRDs (N-CRDs) and the other containing C-terminal CRDs (C-CRDs). The resulting binding surfaces at the opposite ends of the cylindrical trimer have the potential to cross-link cell surface or humoral carbohydrate ligands. The N-CRDs and C-CRDs of MsaFBP32 exhibit significant structural differences, suggesting that they recognize different glycans. Analysis of the carbohydrate binding sites provides the structural basis for the observed specificity of MsaFBP32 for simple carbohydrates and suggests that the N-CRD recognizes more complex fucosylated oligosaccharides and with a relatively higher avidity than the C-CRD. Modeling of MsaFBP32 complexed with fucosylated glycans that are widely distributed in prokaryotes and eukaryotes rationalizes the observation that binary tandem CRD F-type lectins function as opsonins by cross-linking 'non-self' carbohydrate ligands and 'self' carbohydrate ligands, such as sugar structures displayed by microbial pathogens and glycans on the surface of phagocytic cells from the host.

  6. Carbohydrate Recognition Specificity of Trans-sialidase Lectin Domain from Trypanosoma congolense.

    Directory of Open Access Journals (Sweden)

    Mario Waespy

    Full Text Available Fourteen different active Trypanosoma congolense trans-sialidases (TconTS, 11 variants of TconTS1 besides TconTS2, TconTS3 and TconTS4, have been described. Notably, the specific transfer and sialidase activities of these TconTS differ by orders of magnitude. Surprisingly, phylogenetic analysis of the catalytic domains (CD grouped each of the highly active TconTS together with the less active enzymes. In contrast, when aligning lectin-like domains (LD, the highly active TconTS grouped together, leading to the hypothesis that the LD of TconTS modulates its enzymatic activity. So far, little is known about the function and ligand specificity of these LDs. To explore their carbohydrate-binding potential, glycan array analysis was performed on the LD of TconTS1, TconTS2, TconTS3 and TconTS4. In addition, Saturation Transfer Difference (STD NMR experiments were done on TconTS2-LD for a more detailed analysis of its lectin activity. Several mannose-containing oligosaccharides, such as mannobiose, mannotriose and higher mannosylated glycans, as well as Gal, GalNAc and LacNAc containing oligosaccharides were confirmed as binding partners of TconTS1-LD and TconTS2-LD. Interestingly, terminal mannose residues are not acceptor substrates for TconTS activity. This indicates a different, yet unknown biological function for TconTS-LD, including specific interactions with oligomannose-containing glycans on glycoproteins and GPI anchors found on the surface of the parasite, including the TconTS itself. Experimental evidence for such a scenario is presented.

  7. An acetylation site in lectin domain modulates the biological activity of polypeptide GalNAc-transferase-2

    DEFF Research Database (Denmark)

    Zlocowski, Natacha; Lorenz, Virginia; Bennett, Eric Paul;

    2013-01-01

    Abstract Polypeptide GalNAc-transferases (ppGalNAc-Ts) are a family of enzymes that catalyze the initiation of mucin-type O-glycosylation. All ppGalNAc-T family members contain a common (QXW)3 motif which is present in R-type lectin group. Acetylation site K521 is part of the QKW motif of ß......-trefoil in the lectin domain of ppGalNAc-T2. We used a combination of acetylation and site-directed mutagenesis approaches to examine the functional role of K521 in ppGalNAc-T2. Binding assays of non-acetylated and acetylated forms of the mutant ppGalNAc-T2K521Q to various naked and aGalNAc-glycosylated mucin peptides...... indicated that degree of interaction of lectin domain with aGalNAc depends on the peptide sequence of mucin. Studies of inhibitory effect of various carbohydrates on interactions of ppGalNAc-T2 with MUC1aGalNAc indicate that point K521Q mutation enhance the carbohydrate specificity of lectin domain for aGalNAc...

  8. The Distribution of Lectins across the Phylum Nematoda: A Genome-Wide Search

    Directory of Open Access Journals (Sweden)

    Lander Bauters

    2017-01-01

    Full Text Available Nematodes are a very diverse phylum that has adapted to nearly every ecosystem. They have developed specialized lifestyles, dividing the phylum into free-living, animal, and plant parasitic species. Their sheer abundance in numbers and presence in nearly every ecosystem make them the most prevalent animals on earth. In this research nematode-specific profiles were designed to retrieve predicted lectin-like domains from the sequence data of nematode genomes and transcriptomes. Lectins are carbohydrate-binding proteins that play numerous roles inside and outside the cell depending on their sugar specificity and associated protein domains. The sugar-binding properties of the retrieved lectin-like proteins were predicted in silico. Although most research has focused on C-type lectin-like, galectin-like, and calreticulin-like proteins in nematodes, we show that the lectin-like repertoire in nematodes is far more diverse. We focused on C-type lectins, which are abundantly present in all investigated nematode species, but seem to be far more abundant in free-living species. Although C-type lectin-like proteins are omnipresent in nematodes, we have shown that only a small part possesses the residues that are thought to be essential for carbohydrate binding. Curiously, hevein, a typical plant lectin domain not reported in animals before, was found in some nematode species.

  9. The Breast Cancer-Associated Glycoforms of MUC1, MUC1-Tn and sialyl-Tn, Are Expressed in COSMC Wild-Type Cells and Bind the C-Type Lectin MGL.

    Directory of Open Access Journals (Sweden)

    Richard Beatson

    Full Text Available Aberrant glycosylation occurs in the majority of human cancers and changes in mucin-type O-glycosylation are key events that play a role in the induction of invasion and metastases. These changes generate novel cancer-specific glyco-antigens that can interact with cells of the immune system through carbohydrate binding lectins. Two glyco-epitopes that are found expressed by many carcinomas are Tn (GalNAc-Ser/Thr and STn (NeuAcα2,6GalNAc-Ser/Thr. These glycans can be carried on many mucin-type glycoproteins including MUC1. We show that the majority of breast cancers carry Tn within the same cell and in close proximity to extended glycan T (Galβ1,3GalNAc the addition of Gal to the GalNAc being catalysed by the T synthase. The presence of active T synthase suggests that loss of the private chaperone for T synthase, COSMC, does not explain the expression of Tn and STn in breast cancer cells. We show that MUC1 carrying both Tn or STn can bind to the C-type lectin MGL and using atomic force microscopy show that they bind to MGL with a similar dead adhesion force. Tumour associated STn is associated with poor prognosis and resistance to chemotherapy in breast carcinomas, inhibition of DC maturation, DC apoptosis and inhibition of NK activity. As engagement of MGL in the absence of TLR triggering may lead to anergy, the binding of MUC1-STn to MGL may be in part responsible for some of the characteristics of STn expressing tumours.

  10. Recombinant expression and functional characterization of a C-type lectin ( Fclectin ) from the Chinese shrimp ( Fenneropenaeus chinensis )%中国明对虾C-型凝集素基因(Fclectin)的重组表达及活性分析

    Institute of Scientific and Technical Information of China (English)

    刘逸尘; 刘丽静; 张亦陈; 耿绪云; 孙妍; 孙金生

    2012-01-01

    Chinese shrimp (Fenneropenaeus chinensis) is distributed mainly along Chinese inshore areas, and is one of the most important farmed shrimp in China. The studies on innate immune responses of shrimps, especially on immune defense against the main crustacean pathogens,will provide more knowledge of shrimp immunity to prevent infectious diseases. Invertebrates do not possess an adaptive immune system based on highly specific antibodies and antigen receptors. They must rely on efficient immune defenses capable of protecting them against invading microorganisms. The chief issue of crustacean immunity should concern non-self-recognition mechanisms. Proteins that specifically bind to certain carbohydrate components on the surface of microorganisms play an important role in non-self-recognition and cleaning up of the invading microorganisms. Such proteins are known as pattern recognition receptors(PRRs). Lectins exist in almost all living organisms. Due to their ability of binding to terminal sugars on glycoproteins and glycolipids, lectins are primary candidates for pattern recognition receptors in innate immunity. C type Lectin is regarded as a potential molecule involved in immune recognition and phagocytosis through opsonization in crustacean. In the preliminary study,a novel C-type lectin was cloned from hemocytes of Chinese shrimp, ( Fenneropenaeus chinensis). It contains two tandem carbohydrate recognition domains ( CRDs)/C-type lectin-like domains. Both of the CRDs contain a QPD(Gln-Pro-Asp) motif that has a predicted binding specificity for galactose-type sugar. In this research, two recombinant target proteins ( rFclectin-CRDl and rFclectin-CRD2 ) were expressed by prokaryotic expression system. The result showed that fusion protein was expressed in the form of inclusion bodies. The LC-ESI-MS analysis showed that two peptide fragments of rFclectin-CRDl and rFclectin-CRD2 were identical with the corresponding sequence of F. chinensis C-type lectin. Recombinant

  11. 红笛鲷(Lutjanus sanguineus)C型凝集素基因的克隆与组织表达分析%Cloning and Tissue Expression Analysis of C-type Lectin Gene from Humphead Snapper(Lutjanus sanguineus)

    Institute of Scientific and Technical Information of China (English)

    蔡佳; 张雪利; 吴灶和; 简纪常; 鲁义善; 冯东岳; 焦茂兴

    2015-01-01

    根据已知的海水鱼类C型凝集素基因的核苷酸保守区序列设计一对简并引物,先后通过RT-PCR和RACE PCR法从红笛鲷脾脏中首次克隆获得红笛鲷C型凝集素(CTL)基因的cDNA全长(登录号:AGT37609).该序列长828 bp,开放阅读框663 bp,编码220个氨基酸.氨基酸序列分析显示,红笛鲷CTL基因氨基酸序列与其他物种CTL的相似性在30%-68%之间.系统进化分析表明,红笛鲷C型凝集素与鳉鱼、条石鲷、斜带石斑鱼 CTL蛋白亲缘关系最近,聚成一支.通过荧光定量PCR分析红笛鲷基因的组织差异表达,红笛鲷CTL基因在肝、脾以及皮肤中表达水平较高,其次是头肾、肾、胃、肠及肌肉,在心脏与脑中表达量较低.%According to conservative region of known C-type lectin(CTL)gene, a pair of degenerate primers were designed, and full length cDNA sequence of C-type lectin gene was amplified by RT-PCR and RACE PCR from spleen of humphead snapper,Lutjanus sanguineus (GenBank accession number: AGT37609)for the first time. The total cDNA sequence of the gene was 828 bp, consisting of a 663 bp open reading frame(ORF)and encoding 220 amino acids. The deduced amino acid sequence of humphead snapper CTL shared 30%-68% identities with other species CTLs. Phylogenetic analysis showed that humphead snapper CTL was clustered closely with mummichog, rock bream, and orange-spotted grouper CTL. Moreover, the mRNA expression levels in different tissues were analyzed by real time quantitative PCR. The result showed that humphead snapper CTL gene expressed in all tested tissues with highest level in liver, spleen and skin, moderate level in head kidney, kidney, stomach, intestine and muscle, and lowest level in heart and brain.

  12. Generation and characterization of β1,2-gluco-oligosaccharide probes from Brucella abortus cyclic β-glucan and their recognition by C-type lectins of the immune system

    Science.gov (United States)

    Zhang, Hongtao; Palma, Angelina S; Zhang, Yibing; Childs, Robert A; Liu, Yan; Mitchell, Daniel A; Guidolin, Leticia S; Weigel, Wilfried; Mulloy, Barbara; Ciocchini, Andrés E; Feizi, Ten; Chai, Wengang

    2016-01-01

    The β1,2-glucans produced by bacteria are important in invasion, survival and immunomodulation in infected hosts be they mammals or plants. However, there has been a lack of information on proteins which recognize these molecules. This is partly due to the extremely limited availability of the sequence-defined oligosaccharides and derived probes for use in the study of their interactions. Here we have used the cyclic β1,2-glucan (CβG) of the bacterial pathogen Brucella abortus, after removal of succinyl side chains, to prepare linearized oligosaccharides which were used to generate microarrays. We describe optimized conditions for partial depolymerization of the cyclic glucan by acid hydrolysis and conversion of the β1,2-gluco-oligosaccharides, with degrees of polymerization 2–13, to neoglycolipids for the purpose of generating microarrays. By microarray analyses, we show that the C-type lectin receptor DC-SIGNR, like the closely related DC-SIGN we investigated earlier, binds to the β1,2-gluco-oligosaccharides, as does the soluble immune effector serum mannose-binding protein. Exploratory studies with DC-SIGN are suggestive of the recognition also of the intact CβG by this receptor. These findings open the way to unravelling mechanisms of immunomodulation mediated by β1,2-glucans in mammalian systems. PMID:27053576

  13. The lectin domains of polypeptide GalNAc-transferases exhibit carbohydrate-binding specificity for GalNAc: lectin binding to GalNAc-glycopeptide substrates is required for high density GalNAc-O-glycosylation.

    Science.gov (United States)

    Wandall, Hans H; Irazoqui, Fernando; Tarp, Mads Agervig; Bennett, Eric P; Mandel, Ulla; Takeuchi, Hideyuki; Kato, Kentaro; Irimura, Tatsuro; Suryanarayanan, Ganesh; Hollingsworth, Michael A; Clausen, Henrik

    2007-04-01

    Initiation of mucin-type O-glycosylation is controlled by a large family of UDP GalNAc:polypeptide N-acetylgalactosaminyltransferases (GalNAc-transferases). Most GalNAc-transferases contain a ricin-like lectin domain in the C-terminal end, which may confer GalNAc-glycopeptide substrate specificity to the enzyme. We have previously shown that the lectin domain of GalNAc-T4 modulates its substrate specificity to enable unique GalNAc-glycopeptide specificities and that this effect is selectively inhibitable by GalNAc; however, direct evidence of carbohydrate binding of GalNAc-transferase lectins has not been previously presented. Here, we report the direct carbohydrate binding of two GalNAc-transferase lectin domains, GalNAc-T4 and GalNAc-T2, representing isoforms reported to have distinct glycopeptide activity (GalNAc-T4) and isoforms without apparent distinct GalNAc-glycopeptide specificity (GalNAc-T2). Both lectins exhibited specificity for binding of free GalNAc. Kinetic and time-course analysis of GalNAc-T2 demonstrated that the lectin domain did not affect transfer to initial glycosylation sites, but selectively modulated velocity of transfer to subsequent sites and affected the number of acceptor sites utilized. The results suggest that GalNAc-transferase lectins serve to modulate the kinetic properties of the enzymes in the late stages of the initiation process of O-glycosylation to accomplish dense or complete O-glycan occupancy.

  14. Evidence for a lectin activity for human interleukin 3 and modeling of its carbohydrate recognition domain.

    Science.gov (United States)

    Zanetta, Jean-Pierre; Bindeus, Roland; Normand, Guy; Durier, Viviane; Lagant, Philippe; Maes, Emmanuel; Vergoten, Gérard

    2002-10-11

    We demonstrate that human interleukin 3 (IL-3) is a lectin recognizing specifically the glycosaminoglycan part of a chondroitin sulfate proteoglycan (PGS3; Normand, G., Kuchler, S., Meyer, A., Vincendon, G., and Zanetta, J. P. (1988) J. Neurochem. 51, 665-676) isolated from the adult rat brain. The specificity of the interaction of this particular proteoglycan with IL-3 is due to the abundance of GlcA(2S)beta 1,3GalNAc(4S)beta 1 disaccharide units as suggested by (1)H NMR. Computational docking experiments of the lower energy conformers of the different disaccharides from chondroitin sulfates reveal a privileged binding site for GlcA(2S)beta 1,3GalNAc(4S)beta 1 (involving His-26, Arg-29, Asn-70, and Trp-104) localized in an area of IL-3 different from the receptor-binding domain previously identified by others (Bagley, C. J., Phillips, J., Cambareri, B., Vadas, M. A., and Lopez, A. F. (1996) J. Biol. Chem. 271, 31922-31928). Molecular modeling of the mutation P33G, described as increasing the biological activity of IL-3 without affecting its receptor binding (Lokker, N. A., Movva, N. R., Strittmatter, U., Fagg, B., and Zenke, G. (1991) J. Biol. Chem. 266, 10624-10631) provokes a change of the three-dimensional structure of IL-3, especially in the area of the putative carbohydrate recognition domain defined above. Computational docking experiments of the different disaccharides of chondroitin sulfates indicate a loss of affinity for the previous ligand but a higher affinity for the classic disaccharide of chondroitin-4-sulfate. This change from a rare and specific ligand to a more abundant constituent of proteoglycans could induce an increased quantitative association between the IL-3 receptors and its ligands and, consequently, an increased signaling.

  15. Contribution of the CR domain to P-selectin lectin domain allostery by regulating the orientation of the EGF domain.

    Science.gov (United States)

    Lü, Shouqin; Chen, Shenbao; Mao, Debin; Zhang, Yan; Long, Mian

    2015-01-01

    The allostery of P-selectin has been studied extensively with a focus on the Lec and EGF domains, whereas the contribution of the CR domain remains unclear. Here, molecular dynamics simulations (MDS) combined with homology modeling were preformed to investigate the impact of the CR domain on P-selectin allostery. The results indicated that the CR domain plays a role in the allosteric dynamics of P-selectin in two ways. First, the CR1 domain tends to stabilize the low affinity of P-selectin during the equilibration processes with the transition inhibition from the S1 to S1' state by restraining the extension of the bent EGF orientation, or with the relaxation acceleration of the S2 state by promoting the bending of the extended EGF orientation. Second, the existence of CR domain increases intramolecular extension prior to complex separation, increasing the time available for the allosteric shift during forced dissociation with a prolonged bond duration. These findings further our understanding of the structure-function relationship of P-selectin with the enriched micro-structural bases of the CR domain.

  16. The C-terminal domain of the Arabinosyltransferase Mycobacterium tuberculosis EmbC is a lectin-like carbohydrate binding module.

    Directory of Open Access Journals (Sweden)

    Luke J Alderwick

    2011-02-01

    Full Text Available The D-arabinan-containing polymers arabinogalactan (AG and lipoarabinomannan (LAM are essential components of the unique cell envelope of the pathogen Mycobacterium tuberculosis. Biosynthesis of AG and LAM involves a series of membrane-embedded arabinofuranosyl (Araf transferases whose structures are largely uncharacterised, despite the fact that several of them are pharmacological targets of ethambutol, a frontline drug in tuberculosis therapy. Herein, we present the crystal structure of the C-terminal hydrophilic domain of the ethambutol-sensitive Araf transferase M. tuberculosis EmbC, which is essential for LAM synthesis. The structure of the C-terminal domain of EmbC (EmbC(CT encompasses two sub-domains of different folds, of which subdomain II shows distinct similarity to lectin-like carbohydrate-binding modules (CBM. Co-crystallisation with a cell wall-derived di-arabinoside acceptor analogue and structural comparison with ligand-bound CBMs suggest that EmbC(CT contains two separate carbohydrate binding sites, associated with subdomains I and II, respectively. Single-residue substitution of conserved tryptophan residues (Trp868, Trp985 at these respective sites inhibited EmbC-catalysed extension of LAM. The same substitutions differentially abrogated binding of di- and penta-arabinofuranoside acceptor analogues to EmbC(CT, linking the loss of activity to compromised acceptor substrate binding, indicating the presence of two separate carbohydrate binding sites, and demonstrating that subdomain II indeed functions as a carbohydrate-binding module. This work provides the first step towards unravelling the structure and function of a GT-C-type glycosyltransferase that is essential in M. tuberculosis.

  17. The β-prism lectin domain of Vibrio cholerae hemolysin promotes self-assembly of the β-pore-forming toxin by a carbohydrate-independent mechanism.

    Science.gov (United States)

    Ganguly, Sreerupa; Mukherjee, Amarshi; Mazumdar, Budhaditya; Ghosh, Amar N; Banerjee, Kalyan K

    2014-02-14

    Vibrio cholerae cytolysin/hemolysin (VCC) is an amphipathic 65-kDa β-pore-forming toxin with a C-terminal β-prism lectin domain. Because deletion or point mutation of the lectin domain seriously compromises hemolytic activity, it is thought that carbohydrate-dependent interactions play a critical role in membrane targeting of VCC. To delineate the contributions of the cytolysin and lectin domains in pore formation, we used wild-type VCC, 50-kDa VCC (VCC(50)) without the lectin domain, and mutant VCC(D617A) with no carbohydrate-binding activity. VCC and its two variants with no carbohydrate-binding activity moved to the erythrocyte stroma with apparent association constants on the order of 10(7) M(-1). However, loss of the lectin domain severely reduced the efficiency of self-association of the VCC monomer with the β-barrel heptamer in the synthetic lipid bilayer from ∼83 to 27%. Notably, inactivation of the carbohydrate-binding activity by the D617A mutation marginally reduced oligomerization to ∼77%. Oligomerization of VCC(50) was temperature-insensitive; by contrast, VCC self-assembly increased with increasing temperature, suggesting that the process is driven by entropy and opposed by enthalpy. Asialofetuin, the β1-galactosyl-terminated glycoprotein inhibitor of VCC-induced hemolysis, promoted oligomerization of 65-kDa VCC to a species that resembled the membrane-inserted heptamer in stoichiometry and morphology but had reduced global amphipathicity. In conclusion, we propose (i) that the β-prism lectin domain facilitated toxin assembly by producing entropy during relocation in the heptamer and (ii) that glycoconjugates inhibited VCC by promoting its assembly to a water-soluble, less amphipathic oligomer variant with reduced ability to penetrate the bilayer.

  18. Genetically engineered fusion of MAP-1 and factor H domains 1-5 generates a potent dual upstream inhibitor of both the lectin and alternative complement pathways.

    Science.gov (United States)

    Nordmaj, Mie Anemone; Munthe-Fog, Lea; Hein, Estrid; Skjoedt, Mikkel-Ole; Garred, Peter

    2015-12-01

    Inhibition of the complement cascade has emerged as an option for treatment of a range of diseases. Mannose-binding lectin/ficolin/collectin-associated protein (MAP-1) is a pattern recognition molecule (PRM)-associated inhibitor of the lectin pathway. The central regulator of the alternative pathway (AP) is complement factor H (FH). Our aim was to design a dual upstream inhibitor of both human lectin and APs by fusing MAP-1 with a part of FH. There were 2 different recombinant chimeric proteins comprising full-length human MAP-1 and the first 5 N-terminal domains of human FH designed. The FH domains were orientated either in the N- or C-terminal part of MAP-1. The complement inhibition potential in human serum was assessed. Both chimeric constructs displayed the characteristics of the native molecules and bound to the PRMs with an EC50 of ∼ 2 nM. However, when added to serum diluted 1:4 in a solid-phase functional assay, only the first 5 N-terminal domains of complement FH fused to the C-terminal part of full-length MAP-1 chimeric construct were able to combine inhibition of lectin and AP activation with an half maximal inhibitory concentration of ∼ 100 and 20 nM, respectively. No effect was seen on the classical pathway. Fusion of MAP-1 with FH domains represents a novel therapeutic approach for selective targeting upstream and central complement activation at sites of inflammation.

  19. Homology modelling of the core domain of the endogenous lectin comitin: structural basis for its mannose-binding specificity.

    Science.gov (United States)

    Barre, A; Van Damme, E J; Peumans, W J; Rougé, P

    1999-03-01

    The N-terminal core domain of comitin from the slime mold Dictyostelium discoideum has been modelled from the X-ray coordinates of the monocot mannose-binding lectin from snowdrop (Galanthus nivalis). Docking experiments performed on the three-dimensional model showed that two of the three mannose-binding sites of the comitin monomer are functional. They are located at both ends of the comitin dimer whereas the actin-interacting region occurs in the central hinge region where both monomers are non covalently associated. This distribution is fully consistent with the bifunctional character of comitin which is believed to link the Golgi vesicles exhibiting mannosylated membrane glycans to the actin cytoskeleton in the cell.

  20. Elucidation of the sugar recognition ability of the lectin domain of UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase 3 by using unnatural glycopeptide substrates.

    Science.gov (United States)

    Yoshimura, Yayoi; Nudelman, Aaron S; Levery, Steven B; Wandall, Hans H; Bennett, Eric P; Hindsgaul, Ole; Clausen, Henrik; Nishimura, Shin-ichiro

    2012-03-01

    Mucin-type glycosylation [α-N-acetyl-D-galactosamine (α-GalNAc)-O-Ser/Thr] on proteins is initiated biosynthetically by 16 homologous isoforms of GalNAc-Ts (uridine diphosphate-GalNAc:polypeptide N-acetylgalactosaminyltransferases). All the GalNAc-Ts consist of a catalytic domain and a lectin domain. Previous reports of GalNAc-T assays toward peptides and α-GalNAc glycopeptides showed that the lectin domain recognized the sugar on the substrates and affected the reaction; however, the details are not clear. Here, we report a new strategy to give insight on the sugar recognition ability and the function of the GalNAc-T3 lectin domain using chemically synthesized natural-type (α-GalNAc-O-Thr) and unnatural-type [β-GalNAc-O-Thr, α-Fuc-O-Thr and β-GlcNAc-O-Thr] MUC5AC glycopeptides. GalNAc-T3 is one of isoforms expressed in various organs, its substrate specificity extensively characterized and its anomalous expression has been identified in several types of cancer (e.g. pancreas and stomach). The glycopeptides used in this study were designed based on a preliminary peptide assay with a sequence derived from the MUC5AC tandem repeat. Through GalNAc-T3 and lectin-inactivated GalNAc-T3, competition assays between the glycopeptide substrates and product analyses (MALDI-TOF MS, RP-HPLC and ETD-MS/MS), we show that the lectin domain strictly recognized GalNAc on the substrate and this specificity controlled the glycosylation pathway.

  1. A missense mutation in the aggrecan C-type lectin domain disrupts extracellular matrix interactions and causes dominant familial osteochondritis dissecans

    DEFF Research Database (Denmark)

    Stattin, Eva-Lena; Wiklund, Fredrik; Lindblom, Karin;

    2010-01-01

    Osteochondritis dissecans is a disorder in which fragments of articular cartilage and subchondral bone dislodge from the joint surface. We analyzed a five-generation family in which affected members had autosomal-dominant familial osteochondritis dissecans. A genome-wide linkage analysis identifi...

  2. Innate immunity mediated longevity and longevity induced by germ cell removal converge on the C-type lectin domain protein IRG-7

    Science.gov (United States)

    Yunger, Elad; Safra, Modi; Levi-Ferber, Mor; Haviv-Chesner, Anat

    2017-01-01

    In C. elegans, removal of the germline triggers molecular events in the neighboring intestine, which sends an anti-aging signal to the rest of the animal. In this study, we identified an innate immunity related gene, named irg-7, as a novel mediator of longevity in germlineless animals. We consider irg-7 to be an integral downstream component of the germline longevity pathway because its expression increases upon germ cell removal and its depletion interferes with the activation of the longevity-promoting transcription factors DAF-16 and DAF-12 in germlineless animals. Furthermore, irg-7 activation by itself sensitizes the animals' innate immune response and extends the lifespan of animals exposed to live bacteria. This lifespan-extending pathogen resistance relies on the somatic gonad as well as on many genes previously associated with the reproductive longevity pathway. This suggests that these genes are also relevant in animals with an intact gonad, and can affect their resistance to pathogens. Altogether, this study demonstrates the tight association between germline homeostasis and the immune response of animals, and raises the possibility that the reproductive system can act as a signaling center to divert resources towards defending against putative pathogen attacks. PMID:28196094

  3. Wheat Fhb1 encodes a chimeric lectin with agglutinin domains and a pore-forming toxin-like domain conferring resistance to Fusarium head blight.

    Science.gov (United States)

    Rawat, Nidhi; Pumphrey, Michael O; Liu, Sixin; Zhang, Xiaofei; Tiwari, Vijay K; Ando, Kaori; Trick, Harold N; Bockus, William W; Akhunov, Eduard; Anderson, James A; Gill, Bikram S

    2016-12-01

    Fusarium head blight (FHB), caused by Fusarium graminearum, is a devastating disease of wheat and barley that leads to reduced yield and mycotoxin contamination of grain, making it unfit for human consumption. FHB is a global problem, with outbreaks in the United States, Canada, Europe, Asia and South America. In the United States alone, total direct and secondary economic losses from 1993 to 2001 owing to FHB were estimated at $7.67 billion. Fhb1 is the most consistently reported quantitative trait locus (QTL) for FHB resistance breeding. Here we report the map-based cloning of Fhb1 from a Chinese wheat cultivar Sumai 3. By mutation analysis, gene silencing and transgenic overexpression, we show that a pore-forming toxin-like (PFT) gene at Fhb1 confers FHB resistance. PFT is predicted to encode a chimeric lectin with two agglutinin domains and an ETX/MTX2 toxin domain. Our discovery identifies a new type of durable plant resistance gene conferring quantitative disease resistance to plants against Fusarium species.

  4. The Breast Cancer-Associated Glycoforms of MUC1, MUC1-Tn and sialyl-Tn, Are Expressed in COSMC Wild-Type Cells and Bind the C-Type Lectin MGL

    DEFF Research Database (Denmark)

    Beatson, Richard; Maurstad, Gjertrud; Picco, Gianfranco;

    2015-01-01

    and in close proximity to extended glycan T (Galβ1,3GalNAc) the addition of Gal to the GalNAc being catalysed by the T synthase. The presence of active T synthase suggests that loss of the private chaperone for T synthase, COSMC, does not explain the expression of Tn and STn in breast cancer cells. We show...... carbohydrate binding lectins. Two glyco-epitopes that are found expressed by many carcinomas are Tn (GalNAc-Ser/Thr) and STn (NeuAcα2,6GalNAc-Ser/Thr). These glycans can be carried on many mucin-type glycoproteins including MUC1. We show that the majority of breast cancers carry Tn within the same cell...

  5. Biophysical studies on calcium and carbohydrate binding to carbohydrate recognition domain of Gal/GalNAc lectin from Entamoeba histolytica: insights into host cell adhesion.

    Science.gov (United States)

    Yadav, Rupali; Verma, Kuldeep; Chandra, Mintu; Mukherjee, Madhumita; Datta, Sunando

    2016-09-01

    Entamoeba histolytica, an enteric parasite expresses a Gal/GalNAc-specific lectin that contributes to its virulence by establishing adhesion to host cell. In this study, carbohydrate recognition domain of Hgl (EhCRD) was purified and biophysical studies were conducted to understand the thermodynamic basis of its binding to carbohydrate and Ca(++) Here, we show that carbohydrate recognition domain (CRD) of the lectin binds to calcium through DPN motif. To decipher the role of calcium in carbohydrate binding and host cell adhesion, biophysical and cell-based studies were carried out. We demonstrated that the presence of the cation neither change the affinity of the lectin for carbohydrates nor alters its conformation. Mutation of the calcium-binding motif in EhCRD resulted in complete loss of ability to bind calcium but retained its affinity for carbohydrates. Purified EhCRD significantly diminished adhesion of the amebic trophozoites to Chinese Hamster Ovary (CHO) cells as well as triggered red blood cell agglutination. The calcium-binding defective mutant abrogated amebic adhesion to CHO cells similar to the wild-type protein, but it failed to agglutinate RBCs suggesting a differential role of the cation in these two processes. This study provides the first molecular description of the role of calcium in Gal/GalNAc mediated host cell adhesion.

  6. The structure of the cysteine protease and lectin-like domains of Cwp84, a surface layer-associated protein from Clostridium difficile

    Energy Technology Data Exchange (ETDEWEB)

    Bradshaw, William J. [University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Public Health England, Porton Down, Salisbury SP4 0JG (United Kingdom); Kirby, Jonathan M. [Public Health England, Porton Down, Salisbury SP4 0JG (United Kingdom); Thiyagarajan, Nethaji [University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Chambers, Christopher J.; Davies, Abigail H. [University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Public Health England, Porton Down, Salisbury SP4 0JG (United Kingdom); Roberts, April K.; Shone, Clifford C. [Public Health England, Porton Down, Salisbury SP4 0JG (United Kingdom); Acharya, K. Ravi, E-mail: bsskra@bath.ac.uk [University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)

    2014-07-01

    The crystal structure of Cwp84, an S-layer protein from Clostridium difficile is presented for the first time. The cathepsin L-like fold of cysteine protease domain, a newly observed ‘lectin-like’ domain and several other features are described. Clostridium difficile is a major problem as an aetiological agent for antibiotic-associated diarrhoea. The mechanism by which the bacterium colonizes the gut during infection is poorly understood, but undoubtedly involves a myriad of components present on the bacterial surface. The mechanism of C. difficile surface-layer (S-layer) biogenesis is also largely unknown but involves the post-translational cleavage of a single polypeptide (surface-layer protein A; SlpA) into low- and high-molecular-weight subunits by Cwp84, a surface-located cysteine protease. Here, the first crystal structure of the surface protein Cwp84 is described at 1.4 Å resolution and the key structural components are identified. The truncated Cwp84 active-site mutant (amino-acid residues 33–497; C116A) exhibits three regions: a cleavable propeptide and a cysteine protease domain which exhibits a cathepsin L-like fold followed by a newly identified putative carbohydrate-binding domain with a bound calcium ion, which is referred to here as a lectin-like domain. This study thus provides the first structural insights into Cwp84 and a strong base to elucidate its role in the C. difficile S-layer maturation mechanism.

  7. The pepper GNA-related lectin and PAN domain protein gene, CaGLP1, is required for plant cell death and defense signaling during bacterial infection.

    Science.gov (United States)

    Kim, Nak Hyun; Lee, Dong Hyuk; Choi, Du Seok; Hwang, Byung Kook

    2015-12-01

    Carbohydrate-binding proteins, commonly referred to as lectins or agglutinins, function in defense responses to microbial pathogens. Pepper (Capsicum annuum) GNA-related lectin and PAN-domain protein gene CaGLP1 was isolated and functionally characterized from pepper leaves infected with Xanthomonas campestris pv. vesicatoria (Xcv). CaGLP1 contained an amine-terminus prokaryotic membrane lipoprotein lipid attachment site, a Galanthus nivalis agglutinin (GNA)-related lectin domain responsible for the recognition of high-mannose N-glycans, and a carboxyl-terminus PAN/apple domain. RNA gel blot and immunoblot analyses determined that CaGLP1 was strongly induced in pepper by compatible and incompatible Xcv infection. CaGLP1 protein localized primarily to the plasma membrane and exhibited mannose-binding specificity. CaGLP1-silenced pepper plants were more susceptible to compatible or incompatible Xcv infection compared with that of non-silenced control plants. CaGLP1 silencing in pepper leaves did not accumulate H2O2 and induce cell death during incompatible Xcv infection. Defense-related CaDEF1 (defensin) gene expression was significantly reduced in CaGLP1-silenced pepper plants. CaGLP1-overexpression in Arabidopsis thaliana enhanced resistance to Pseudomonas syringae pv. tomato. Defense-related AtPDF1.2 expression was elevated in CaGLP1-overexpression lines. Together, these results suggest that CaGLP1 is required for plant cell death and defense responses through the reactive oxygen species burst and downstream defense-related gene expression in response to bacterial pathogen challenge.

  8. Targeting the Cryptococcus neoformans var. grubii Cell Wall Using Lectins: Study of the Carbohydrate-Binding Domain

    Directory of Open Access Journals (Sweden)

    Pamella de Brito Ximenes

    2015-02-01

    Full Text Available Cryptococcus neoformans var. grubii is considered to be the major cause of cryptococcosis in immunosuppressed patients. Understanding cell wall glycoproteins using lectins is of medical interest and can contribute to specific therapy. The aim of this study was to evaluate the carbohydrates on the cell wall of Cryptococcus neoformans var. grubii clinical isolates, using a fluorescein isothiocyanate-lectin binding protocol. Thirty yeast strains stocked in the culture collection were cultivated for 2 days at 30 °C with shaking. Cells were obtained by centrifugation, washed in phosphate-buffered saline, and a suspension of 107 cells/mL was obtained. To determine the binding profile of lectins, concanavalin A (Con A, wheat germ agglutinin (WGA, Ulex europaeus agglutinin I (UEA-I, and peanut agglutinin (PNA conjugated to fluorescein were used. All the tested clinical isolates of Cryptococcus neoformans var. grubii were intensely stained by WGA, moderately stained by Con A, and weakly stained by PNA and UEA-I. Thus, Cryptococcus can be detected in clinical specimens such as blood and cerebrospinal fluid using the fluorescent lectin WGA, which may be considered as an option for detection in cases of suspected cryptococcosis with low laboratory sensitivity. Future applications may be developed using this basic tool.

  9. Structures and solution properties of two novel periplasmic sensor domains with c-type heme from chemotaxis proteins of Geobacter sulfurreducens : implications for signal transduction.

    Energy Technology Data Exchange (ETDEWEB)

    Pokkuluri, P. R.; Pessanha, M.; Londer, Y. Y.; Wood, S. J.; Duke, N. E. C.; Wilton, R.; Catarino, T.; Salgueiro, C. A.; Schiffer, M.; Biosciences Division; Univ.Nova de Lisboa; Insti. de Tecnologia Quimica e Biologica

    2008-04-11

    Periplasmic sensor domains from two methyl-accepting chemotaxis proteins from Geobacter sulfurreducens (encoded by genes GSU0935 and GSU0582) were expressed in Escherichia coli. The sensor domains were isolated, purified, characterized in solution, and their crystal structures were determined. In the crystal, both sensor domains form swapped dimers and show a PAS-type fold. The swapped segment consists of two helices of about 45 residues at the N terminus with the hemes located between the two monomers. In the case of the GSU0582 sensor, the dimer contains a crystallographic 2-fold symmetry and the heme is coordinated by an axial His and a water molecule. In the case of the GSU0935 sensor, the crystals contain a non-crystallographic dimer, and surprisingly, the coordination of the heme in each monomer is different; monomer A heme has His-Met ligation and monomer B heme has His-water ligation as found in the GSU0582 sensor. The structures of these sensor domains are the first structures of PAS domains containing covalently bound heme. Optical absorption, electron paramagnetic resonance and NMR spectroscopy have revealed that the heme groups of both sensor domains are high-spin and low-spin in the oxidized and reduced forms, respectively, and that the spin-state interconversion involves a heme axial ligand replacement. Both sensor domains bind NO in their ferric and ferrous forms but bind CO only in the reduced form. The binding of both NO and CO occurs via an axial ligand exchange process, and is fully reversible. The reduction potentials of the sensor domains differ by 95 mV (-156 mV and -251 mV for sensors GSU0582 and GSU0935, respectively). The swapped dimerization of these sensor domains and redox-linked ligand switch might be related to the mechanism of signal transduction by these chemotaxis proteins.

  10. Serum levels of mannan-binding lectin in chickens prior to and during experimental infection with avian infectious bronchitis virus

    DEFF Research Database (Denmark)

    Juul-Madsen, H.R.; Munch, M.; Handberg, Kurt;

    2003-01-01

    Mannan-binding lectin (MBL) is a glycoprotein and a member of the C-type lectin super family, the collectin family, and the acute phase protein family. The MBL exerts its function by directly binding to microbial surfaces through its carbohydrate recognition domains, followed by direct opsonization...... that the acute phase MBL response to infection with IBV was, to a degree (P ...%, whereas the acute phase response in chickens challenged after 12 h of rest peaked after 3.1 d with an increase of 51%. The specific antibody titer against IBV was also tested, and a difference (P

  11. Purification, characterization and cDNA cloning of a novel lipopolysaccharide-binding lectin from the shrimp Penaeus monodon.

    Science.gov (United States)

    Luo, Tian; Yang, Haijie; Li, Fang; Zhang, Xiaobo; Xu, Xun

    2006-01-01

    In invertebrates, C-type lectin plays an important role in innate immunity by mediating the recognition of pathogens to host cells and clearing microinvaders. A few C-type lectins have been identified from shrimps, but none of their gene or protein sequences is known to date. In this paper, a C-type lectin (named PmLec) specific for bacterial lipopolysaccharide was purified from the serum of the shrimp Penaeus monodon. The binding of PmLec to lipopolysaccharide was mainly mediated through the O-antigen. PmLec had a strong hemagglutinating and bacterial-agglutinating activity as well as an opsonic effect that enhances hemocyte phagocytosis. The PmLec cDNA sequence was obtained from the cDNA library of P. monodon by polymerase chain reaction with the degenerated primer designed according to the amino-terminal residue sequence of purified PmLec. A 546-bp open reading frame was found to encode a putative protein comprising 182 amino acids and containing a preceding signal peptide of 17 amino acids. A C-type lectin domain existed in PmLec, but no glycosylation site was found. The recombinant PmLec protein expressed in Escherichia coli also showed the same agglutinating activity and opsonic effect as that of the native protein. This is the first report of a lectin cDNA from the shrimp. PmLec functions as a pattern-recognition protein and an opsonin in the shrimp, and it provides a clue to elucidate the role of lectin in the innate immunity of aquatic invertebrates at the molecular level.

  12. Mannose-Binding Lectin Binds to Amyloid Protein and Modulates Inflammation

    Directory of Open Access Journals (Sweden)

    Mykol Larvie

    2012-01-01

    Full Text Available Mannose-binding lectin (MBL, a soluble factor of the innate immune system, is a pattern recognition molecule with a number of known ligands, including viruses, bacteria, and molecules from abnormal self tissues. In addition to its role in immunity, MBL also functions in the maintenance of tissue homeostasis. We present evidence here that MBL binds to amyloid β peptides. MBL binding to other known carbohydrate ligands is calcium-dependent and has been attributed to the carbohydrate-recognition domain, a common feature of other C-type lectins. In contrast, we find that the features of MBL binding to Aβ are more similar to the reported binding characteristics of the cysteine-rich domain of the unrelated mannose receptor and therefore may involve the MBL cysteine-rich domain. Differences in MBL ligand binding may contribute to modulation of inflammatory response and may correlate with the function of MBL in processes such as coagulation and tissue homeostasis.

  13. Genetically engineered fusion of MAP-1 and factor H domains 1-5 generates a potent dual upstream inhibitor of both the lectin and alternative complement pathways

    DEFF Research Database (Denmark)

    Nordmaj, Mie Anemone; Munthe-Fog, Lea; Hein, Estrid;

    2015-01-01

    Inhibition of the complement cascade has emerged as an option for treatment of a range of diseases. Mannose-binding lectin/ficolin/collectin-associated protein (MAP-1) is a pattern recognition molecule (PRM)-associated inhibitor of the lectin pathway. The central regulator of the alternative...

  14. Synthetic fusion-protein containing domains of Bt Cry1Ac and Allium sativum lectin (ASAL) conferred enhanced insecticidal activity against major lepidopteran pests.

    Science.gov (United States)

    Tajne, Sunita; Boddupally, Dayakar; Sadumpati, Vijayakumar; Vudem, Dashavantha Reddy; Khareedu, Venkateswara Rao

    2014-02-10

    Different transgenic crop plants, developed with δ-endotoxins of Bacillus thuringiensis (Bt) and mannose-specific plant lectins, exhibited significant protection against chewing and sucking insects. In the present study, a synthetic gene (cry-asal) encoding the fusion-protein having 488 amino acids, comprising DI and DII domains from Bt Cry1Ac and Allium sativum agglutinin (ASAL), was cloned and expressed in Escherichia coli. Ligand blot analysis disclosed that the fusion-protein could bind to more number of receptors of brush border membrane vesicle (BBMV) proteins of Helicoverpa armigera. Artificial diet bioassays revealed that 0.025 μg/g and 0.50 μg/g of fusion-protein were sufficient to cause 100% mortality in Pectinophora gossypiella and H. armigera insects, respectively. As compared to Cry1Ac, the fusion-protein showed enhanced (8-fold and 30-fold) insecticidal activity against two major lepidopteran pests. Binding of fusion-protein to the additional receptors in the midgut cells of insects is attributable to its enhanced entomotoxic effect. The synthetic gene, first of its kind, appears promising and might serve as a potential candidate for engineering crop plants against major insect pests.

  15. Domain Modeling: NP_001993.2 [SAHG[Archive

    Lifescience Database Archive (English)

    Full Text Available NP_001993.2 chr19 C-type lectin domain d1xarb_ chr19/NP_001993.2/NP_001993.2_apo_14...4-288.pdb d1k9ja_ chr19/NP_001993.2/NP_001993.2_holo_144-288.pdb blast 214A,215S,216H,217T,218G,225N,229K,23

  16. Elucidation of the sugar recognition ability of the lectin domain of UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase 3 by using unnatural glycopeptide substrates

    DEFF Research Database (Denmark)

    Yoshimura, Yayoi; Nudelman, Aaron S; Levery, Steven B;

    2012-01-01

    anomalous expression has been identified in several types of cancer (e.g. pancreas and stomach). The glycopeptides used in this study were designed based on a preliminary peptide assay with a sequence derived from the MUC5AC tandem repeat. Through GalNAc-T3 and lectin-inactivated GalNAc-T3, competition...

  17. The relationship between expressions of C-type lectin receptors on natural killer cells and infant human cytomegalovirus infection%婴儿巨细胞病毒感染与自然杀伤细胞C型凝集素受体的表达

    Institute of Scientific and Technical Information of China (English)

    郭红梅; 李玫; 林谦; 张兰芳

    2010-01-01

    目的 探讨自然杀伤(NK)细胞C型凝集素受体表达与婴儿人巨细胞病毒(HCMV)感染的关系.方法 2006年1月至2008年6月HCMV感染患儿79例和母乳性黄疸对照患儿39例.根据外周血中性粒细胞pp65抗原血症结果,分为活动性HCMV感染组48例和非活动性HCMV感染组31例,并对活动性HCMV感染组的48例婴儿进行更昔洛韦治疗2周.应用流式细胞术检测外周血NK细胞C型凝集素受体NKG2A、NKG2C、NKG2D表达.三组数据比较采用Kruskal-Wallis独立样本非参数检验,两组之间比较采用Mann-Whiteney配对样本非参数检验.结果 NK细胞抑制性受体NKG2A表达在活动性HCMV感染组、非活动性HCMV感染组和对照组之间差异无统计学意义(x2=3.95,P>0.05);NK细胞活化性受体NKG2C、NKG2D表达在活动性HCMV感染组、非活动性HCMV感染组和对照组之间差异有统计学意义(x2=24.91,P<0.01;x2=47.80,P<0.01).NK细胞活化性受体NKG2C、NKG2D表达在HCMV感染组较对照组明显升高(Z=-4.72,P<0.01;Z=-5.15,P<0.01).NK细胞活化性受体NKG2D表达在活动性HCMV感染组较非活动性HCMV感染组明显升高(Z=-5.08,P<0.01).更昔洛韦治疗后NK细胞活化性受体NKG2D表达降低(Z=-1.34,P=0.07).结论 在调节NK细胞功能和婴儿抗HCMV免疫方面,NKG2C和NKG2D表达可能起重要作用.%Objective To explore the relationship between expressions of C-type lectin receptors on natural killer(NK) cells and infant human cytomegalovirus (HCMV) infection. Methods Seventynine cases of HCMV infection infants and 39 cases of HCMV non-infection control infants admitted during January 2006 to June 2008 were recruited in this study. According to HCMV pp65 antigenemia levels in the peripheral blood, 79 cases of HCMV infection infants were divided into two groups: 48cases of active HCMV infection and 31 cases of inactive HCMV infection. The 48 cases of infants with active HCMV infection were treated with ganciclovir for 2 weeks. The

  18. C型凝集素1受体参与人中性粒细胞体外杀伤白念珠菌活性的实验研究%Dectin-1, a C-type lectin receptor, participates in the killing of Candida albicans by human neutrophils: an experimental study

    Institute of Scientific and Technical Information of China (English)

    陈青; 曾荣; 沈永年; 胡素泉; 李岷; 刘维达

    2013-01-01

    目的 探讨人中性粒细胞能否通过C型凝集素1受体(dectin-1)识别白念珠菌细胞壁不溶性β葡聚糖来介导体外杀伤白念珠菌的活性.方法 100 mg/L β葡聚糖体外作用于中性粒细胞1、6、24 h后,实时荧光定量逆转录PCR分析dectin-1和Toll样受体2 mRNA表达水平.100 mg/Lβ葡聚糖体外分别刺激中性粒细胞15 min、2h、6h,或先用dectin-1抑制剂昆布多糖100 mg/L和50 mg/L预处理30 min后,再予100 mg/L β葡聚糖刺激2h,微量培养板荧光分析法检测中性粒细胞H2O2释放水平.昆布多糖预处理的中性粒细胞与白念珠菌体外共培养后,检测菌落形成单位(CFU).结果 β葡聚糖作用中性粒细胞1、6、24 h后,dectin-1 mRNA水平分别为2.8195±0.1669、5.4859±0.7244、3.6041±0.5372,均明显高于空白对照组(均P< 0.01).β葡聚糖刺激中性粒细胞15 min后H2O2水平为(64.55±15.67) μmol/L,2h时为(290.34±30.56)μmol/L,6h时为(208.54±26.88) μmol/L,与空白对照组(22.05±3.99) μmol/L比较,差异均有统计学意义(均P< 0.01);100 mg/L和50 mg/L昆布多糖预处理组分别为(80.45±22.41) μmol/L和(130.42±44.55) μmol/L,与β葡聚糖刺激组相比,分别降低了73%和45%,差异均有统计学意义(P<0.01).昆布多糖能明显抑制中性粒细胞体外杀伤白念珠菌的活性(均P< 0.01).结论 Dectin-1参与人中性粒细胞分泌H2O2以及对白念珠菌杀灭活性,为过继性粒细胞转输治疗系统性念珠菌感染提供初步依据.%Objective To investigate whether human neutrophils kill Candida albicans through recognition of insoluble β-glucan in cell walls of C.albicans (CalG) by dectin-1,a C-type lectin receptor.Methods Neutrophils were obtained from peripheral blood of healthy human subjects and cultured in vitro.Real-time PCR was carried out to quantify the mRNA expressions of dectin-1 and Toll-like receptor 2 (TLR2) in neutrophils challenged with CaIG of 100 mg/L for 1,6,and 24 hours.A Fluoro

  19. The mannose-specific lectin domains of Flo1p from Saccharomyces cerevisiae and Lg-Flo1p from S. pastorianus: crystallization and preliminary X-ray diffraction analysis of the adhesin-carbohydrate complexes.

    Science.gov (United States)

    Ielasi, Francesco S; Goyal, Parveen; Sleutel, Mike; Wohlkonig, Alexandre; Willaert, Ronnie G

    2013-07-01

    Flo1p and Lg-Flo1p are two cell-wall adhesins belonging to the Flo (flocculation) protein family from the yeasts Saccharomyces cerevisiae and S. pastorianus. The main function of these modular proteins endowed with calcium-dependent lectin activity is to mediate cell-cell adhesion events during yeast flocculation, a process which is well known at the cellular level but still not fully characterized from a molecular perspective. Recently, structural features of the N-terminal Flo lectin domains, including the N-terminal domain of Lg-Flo1p (N-Lg-Flo1p), and their interactions with carbohydrate molecules have been investigated. However, structural data concerning the N-terminal domain of Flo1p (N-Flo1p), which is the most specific among the Flo proteins, are missing and information about the N-Lg-Flo1p-carbohydrate interaction still lacks detailed structural insight. Here, the crystallization and preliminary X-ray characterization of the apo form and the mannose complex of N-Flo1p and X-ray analysis of N-Lg-Flo1p crystals soaked in α-1,2-mannobiose are reported. The N-Flo1p crystals diffracted to a resolution of 1.43 Å in the case of the apo form and to 2.12 Å resolution for the mannose complex. Both crystals were orthorhombic and belonged to space group P212121, with one molecule in the asymmetric unit. The N-Lg-Flo1p-α-1,2-mannobiose complex crystal diffracted to 1.73 Å resolution and belonged to the monoclinic space group P1211 with two molecules in the asymmetric unit.

  20. The lectin domain of the polypeptide GalNAc transferase family of glycosyltransferases (ppGalNAc Ts) acts as a switch directing glycopeptide substrate glycosylation in an N- or C-terminal direction, further controlling mucin type O-glycosylation.

    Science.gov (United States)

    Gerken, Thomas A; Revoredo, Leslie; Thome, Joseph J C; Tabak, Lawrence A; Vester-Christensen, Malene Bech; Clausen, Henrik; Gahlay, Gagandeep K; Jarvis, Donald L; Johnson, Roy W; Moniz, Heather A; Moremen, Kelley

    2013-07-01

    Mucin type O-glycosylation is initiated by a large family of polypeptide GalNAc transferases (ppGalNAc Ts) that add α-GalNAc to the Ser and Thr residues of peptides. Of the 20 human isoforms, all but one are composed of two globular domains linked by a short flexible linker: a catalytic domain and a ricin-like lectin carbohydrate binding domain. Presently, the roles of the catalytic and lectin domains in peptide and glycopeptide recognition and specificity remain unclear. To systematically study the role of the lectin domain in ppGalNAc T glycopeptide substrate utilization, we have developed a series of novel random glycopeptide substrates containing a single GalNAc-O-Thr residue placed near either the N or C terminus of the glycopeptide substrate. Our results reveal that the presence and N- or C-terminal placement of the GalNAc-O-Thr can be important determinants of overall catalytic activity and specificity that differ between transferase isoforms. For example, ppGalNAc T1, T2, and T14 prefer C-terminally placed GalNAc-O-Thr, whereas ppGalNAc T3 and T6 prefer N-terminally placed GalNAc-O-Thr. Several transferase isoforms, ppGalNAc T5, T13, and T16, display equally enhanced N- or C-terminal activities relative to the nonglycosylated control peptides. This N- and/or C-terminal selectivity is presumably due to weak glycopeptide binding to the lectin domain, whose orientation relative to the catalytic domain is dynamic and isoform-dependent. Such N- or C-terminal glycopeptide selectivity provides an additional level of control or fidelity for the O-glycosylation of biologically significant sites and suggests that O-glycosylation may in some instances be exquisitely controlled.

  1. The Lectin Domain of the Polypeptide GalNAc Transferase Family of Glycosyltransferases (ppGalNAc Ts) Acts as a Switch Directing Glycopeptide Substrate Glycosylation in an N- or C-terminal Direction, Further Controlling Mucin Type O-Glycosylation

    DEFF Research Database (Denmark)

    Gerken, Thomas A; Revoredo, Leslie; Thome, Joseph J C

    2013-01-01

    Mucin type O-glycosylation is initiated by a large family of polypeptide GalNAc transferases (ppGalNAc Ts) that add α-GalNAc to the Ser and Thr residues of peptides. Of the 20 human isoforms, all but one are composed of two globular domains linked by a short flexible linker: a catalytic domain...... relative to the nonglycosylated control peptides. This N- and/or C-terminal selectivity is presumably due to weak glycopeptide binding to the lectin domain, whose orientation relative to the catalytic domain is dynamic and isoform-dependent. Such N- or C-terminal glycopeptide selectivity provides...

  2. Recombinant lectins: an array of tailor-made glycan-interaction biosynthetic tools.

    Science.gov (United States)

    Oliveira, Carla; Teixeira, José A; Domingues, Lucília

    2013-03-01

    Lectins are a heterogeneous group of proteins found in plants, animals and microorganisms, which possess at least one non-catalytic domain that binds reversibly to specific mono- or oligosaccharides. The range of lectins and respective biological activities is unsurprising given the immense diversity and complexity of glycan structures and the multiple modes of interaction with proteins. Recombinant DNA technology has been traditionally used for cloning and characterizing newly discovered lectins. It has also been employed as a means of producing pure and sequence-defined lectins for different biotechnological applications. This review focuses on the production of recombinant lectins in heterologous organisms, and highlighting the Escherichia coli and Pichia pastoris expression systems, which are the most employed. The choice of expression host depends on the lectin. Non-glycosylated recombinant lectins are produced in E. coli and post-translational modified recombinant lectins are produced in eukaryotic organisms, namely P. pastoris and non-microbial hosts such as mammalian cells. Emphasis is given to the applications of the recombinant lectins especially (a) in cancer diagnosis and/or therapeutics, (b) as anti-microbial, anti-viral, and anti-insect molecules or (c) in microarrays for glycome profiling. Most reported applications are from recombinant plant lectins. These applications benefit from the tailor-made design associated with recombinant production and will aid in unraveling the complex biological mechanisms of glycan-interactions, bringing recombinant lectins to the forefront of glycobiology. In conclusion, recombinant lectins are developing into valuable biosynthetic tools for biomedical research.

  3. Latent Ice Recrystallization Inhibition Activity in Nonantifreeze Proteins: Ca2+-Activated Plant Lectins and Cation-Activated Antimicrobial Peptides.

    Science.gov (United States)

    Mitchell, Daniel E; Gibson, Matthew I

    2015-10-12

    Organisms living in polar regions have evolved a series of antifreeze (glyco) proteins (AFGPs) to enable them to survive by modulating the structure of ice. These proteins have huge potential for use in cellular cryopreservation, ice-resistant surfaces, frozen food, and cryosurgery, but they are limited by their relatively low availability and questions regarding their mode of action. This has triggered the search for biomimetic materials capable of reproducing this function. The identification of new structures and sequences capable of inhibiting ice growth is crucial to aid our understanding of these proteins. Here, we show that plant c-type lectins, which have similar biological function to human c-type lectins (glycan recognition) but no sequence homology to AFPs, display calcium-dependent ice recrystallization inhibition (IRI) activity. This IRI activity can be switched on/off by changing the Ca2+ concentration. To show that more (nonantifreeze) proteins may exist with the potential to display IRI, a second motif was considered, amphipathicity. All known AFPs have defined hydrophobic/hydrophilic domains, rationalizing this choice. The cheap, and widely used, antimicrobial Nisin was found to have cation-dependent IRI activity, controlled by either acid or addition of histidine-binding ions such as zinc or nickel, which promote its amphipathic structure. These results demonstrate a new approach in the identification of antifreeze protein mimetic macromolecules and may help in the development of synthetic mimics of AFPs.

  4. Unique posttranslational modifications of chitin-binding lectins of Entamoeba invadens cyst walls.

    Science.gov (United States)

    Van Dellen, Katrina L; Chatterjee, Anirban; Ratner, Daniel M; Magnelli, Paula E; Cipollo, John F; Steffen, Martin; Robbins, Phillips W; Samuelson, John

    2006-05-01

    Entamoeba histolytica, which causes amebic dysentery and liver abscesses, is spread via chitin-walled cysts. The most abundant protein in the cyst wall of Entamoeba invadens, a model for amebic encystation, is a lectin called EiJacob1. EiJacob1 has five tandemly arrayed, six-Cys chitin-binding domains separated by low-complexity Ser- and Thr-rich spacers. E. histolytica also has numerous predicted Jessie lectins and chitinases, which contain a single, N-terminal eight-Cys chitin-binding domain. We hypothesized that E. invadens cyst walls are composed entirely of proteins with six-Cys or eight-Cys chitin-binding domains and that some of these proteins contain sugars. E. invadens genomic sequences predicted seven Jacob lectins, five Jessie lectins, and three chitinases. Reverse transcription-PCR analysis showed that mRNAs encoding Jacobs, Jessies, and chitinases are increased during E. invadens encystation, while mass spectrometry showed that the cyst wall is composed of an approximately 30:70 mix of Jacob lectins (cross-linking proteins) and Jessie and chitinase lectins (possible enzymes). Three Jacob lectins were cleaved prior to Lys at conserved sites (e.g., TPSVDK) in the Ser- and Thr-rich spacers between chitin-binding domains. A model peptide was cleaved at the same site by papain and E. invadens Cys proteases, suggesting that the latter cleave Jacob lectins in vivo. Some Jacob lectins had O-phosphodiester-linked carbohydrates, which were one to seven hexoses long and had deoxysugars at reducing ends. We concluded that the major protein components of the E. invadens cyst wall all contain chitin-binding domains (chitinases, Jessie lectins, and Jacob lectins) and that the Jacob lectins are differentially modified by site-specific Cys proteases and O-phosphodiester-linked glycans.

  5. Structure and Function of Mammalian Carbohydrate-Lectin Interactions

    Science.gov (United States)

    Anderson, Kevin; Evers, David; Rice, Kevin G.

    Over the past three decades the field of glycobiology has expanded beyond a basic understanding of the structure and biosynthesis of glycoprotein, proteoglycans, and glycolipids toward a more detailed picture of how these molecules afford communication through binding to mammalian lectins. Although the number of different mammalian lectin domains appears to be finite and even much smaller than early estimates predicated based on the diversity of glycan structures, nature appears capable of using these in numerous combinations to fine tune specificity. The following provides an overview of the major classes of mammalian lectins and discusses their glycan binding specificity. The review provides a snapshot of the field of glycobiology that continues to grow providing an increasing number of examples of biological processes that rely upon glycan-lectin binding.

  6. The different roles of aggrecan interaction domains

    DEFF Research Database (Denmark)

    Aspberg, Anders

    2012-01-01

    is vital in that it binds the proteoglycan to hyaluronan in ternary complex with link protein, retaining the proteoglycan in the tissue. The importance of the C-terminal G3 domain interactions has recently been emphasized by two different human hereditary disorders: autosomal recessive aggrecan......The aggregating proteoglycans of the lectican family are important components of extracellular matrices. Aggrecan is the most well studied of these and is central to cartilage biomechanical properties and skeletal development. Key to its biological function is the fixed charge of the many......-type spondyloepimetaphyseal dysplasia and autosomal dominant familial osteochondritis dissecans. In these two conditions, different missense mutations in the aggrecan C-type lectin repeat have been described. The resulting amino acid replacements affect the ligand interactions of the G3 domain, albeit with widely different...

  7. Animal lectins as self/non-self recognition molecules. Biochemical and genetic approaches to understanding their biological roles and evolution.

    Science.gov (United States)

    Vasta, G R; Ahmed, H; Fink, N E; Elola, M T; Marsh, A G; Snowden, A; Odom, E W

    1994-04-15

    In recent years, the significant contributions from molecular research studies on animal lectins have elucidated structural aspects and provided clues not only to their evolution but also to their multiple biological functions. The experimental evidence has suggested that distinct, and probably unrelated, groups of molecules are included under the term "lectin." Within the invertebrate taxa, major groups of lectins can be identified: One group would include lectins that show significant homology to membrane-integrated or soluble vertebrate C-type lectins. The second would include those beta-galactosyl-specific lectins homologous to the S-type vertebrate lectins. The third group would be constituted by lectins that show homology to vertebrate pentraxins that exhibit lectin-like properties, such as C-reactive protein and serum amyloid P. Finally, there are examples that do not exhibit similarities to any of the aforementioned categories. Moreover, the vast majority of invertebrate lectins described so far cannot yet be placed in one or another group because of the lack of information regarding their primary structure. (See Table 1.) Animal lectins do not express a recombinatorial diversity like that of antibodies, but a limited diversity in recognition capabilities would be accomplished by the occurrence of multiple lectins with distinct specificities, the presence of more than one binding site, specific for different carbohydrates in a single molecule, and by certain "flexibility" of the binding sites that would allow the recognition of a range of structurally related carbohydrates. In order to identify the lectins' "natural" ligands, we have investigated the interactions between those proteins and the putative endogenous or exogenous glycosylated substances or cells that may be relevant to their biological function. Results from these studies, together with information on the biochemical properties of invertebrate and vertebrate lectins, including their structural

  8. Multiplicity of carbohydrate-binding sites in -prism fold lectins: occurrence and possible evolutionary implications

    Indian Academy of Sciences (India)

    Alok Sharma; Divya Chandran; Desh D Singh; M Vijayan

    2007-09-01

    The -prism II fold lectins of known structure, all from monocots, invariably have three carbohydrate-binding sites in each subunit/domain. Until recently, -prism I fold lectins of known structure were all from dicots and they exhibited one carbohydrate-binding site per subunit/domain. However, the recently determined structure of the -prism fold I lectin from banana, a monocot, has two very similar carbohydrate-binding sites. This prompted a detailed analysis of all the sequences appropriate for two-lectin folds and which carry one or more relevant carbohydrate-binding motifs. The very recent observation of a -prism I fold lectin, griffithsin, with three binding sites in each domain further confirmed the need for such an analysis. The analysis demonstrates substantial diversity in the number of binding sites unrelated to the taxonomical position of the plant source. However, the number of binding sites and the symmetry within the sequence exhibit reasonable correlation. The distribution of the two families of -prism fold lectins among plants and the number of binding sites in them, appear to suggest that both of them arose through successive gene duplication, fusion and divergent evolution of the same primitive carbohydrate-binding motif involving a Greek key. Analysis with sequences in individual Greek keys as independent units lends further support to this conclusion. It would seem that the preponderance of three carbohydrate-binding sites per domain in monocot lectins, particularly those with the -prism II fold, is related to the role of plant lectins in defence.

  9. Lectin-like domain of thrombomodulin binds to its specific ligand Lewis Y antigen and neutralizes lipopolysaccharide-induced inflammatory response

    Science.gov (United States)

    Shi, Chung-Sheng; Hsiao, Shi-Ming; Kao, Yuan-Chung; Kuo, Kuan-Lin; Ma, Chih-Yuan; Kuo, Cheng-Hsiang; Chang, Bi-Ing; Chang, Chuan-Fa; Lin, Chun-Hung; Wong, Chi-Huey

    2008-01-01

    Thrombomodulin (TM), a widely expressing glycoprotein originally identified in vascular endothelium, is an important cofactor in the protein C anticoagulant system. TM appears to exhibit anti-inflammatory ability through both protein C–dependent and –independent pathways. We presently have demonstrated that recombinant N-terminal lectinlike domain of TM (rTMD1) functions as a protective agent against sepsis caused by Gram-negative bacterial infections. rTMD1 caused agglutination of Escherichia coli and Klebsiella pneumoniae and enhanced the macrophage phagocytosis of these Gram-negative bacteria. Moreover, rTMD1 bound to the Klebsiella pneumoniae and lipopolysaccharide (LPS) by specifically interacting with Lewis Y antigen. rTMD1 inhibited LPS-induced inflammatory mediator production via interference with CD14 and LPS binding. Furthermore, rTMD1 modulated LPS-induced mitogen-activated protein kinase and nuclear factor-κB signaling pathway activations and inducible nitric oxide synthase expression in macrophages. Administration of rTMD1 protected the host by suppressing inflammatory responses induced by LPS and Gram-negative bacteria, and enhanced LPS and bacterial clearance in sepsis. Thus, rTMD1 can be used to defend against bacterial infection and inhibit LPS-induced inflammatory responses, suggesting that rTMD1 may be valuable in the treatment of severe inflammation in sepsis, especially in Gram-negative bacterial infections. PMID:18711002

  10. Lectin-like molecules in transcriptome of Littorina littorea hemocytes.

    Science.gov (United States)

    Gorbushin, Alexander M; Borisova, Elena A

    2015-01-01

    The common periwinkle Littorina littorea was introduced in the list of models for comparative immunobiology as a representative of phylogenetically important taxon Caenogastropoda. Using Illumina sequencing technology, we de novo assembled the transcriptome of Littorina littorea hemocytes from 182 million mRNA-Seq pair-end 100 bp reads into a total of 15,526 contigs clustered in 4472 unigenes. The transcriptome profile was analyzed for presence of carbohydrate-binding molecules in a variety of architectural contexts. Hemocytes' repertoire of lectin-like proteins bearing conserved carbohydrate-recognition domains (CRDs) is highly diversified, including 11 of 15 lectin families earlier described in animals, as well as the novel members of lectin family found for the first time in mollusc species. The new molluscan lineage-specific domain combinations were confirmed by cloning and sequencing, including the fuco-lectin related molecules (FLReMs) composed of N-terminal region with no sequence homology to any known protein, a middle Fucolectin Tachylectin-4 Pentaxrin (FTP) domain, and a C-terminal epidermal growth factor (EGF) repeat region. The repertoire of lectin-like molecules is discussed in terms of their potential participation in the receptor phase of immune response. In total, immune-associated functions may be attributed to 70 transcripts belonging to 6 lectin families. These lectin-like genes show low overlap between species of invertebrates, suggesting relatively rapid evolution of immune-associated genes in the group. The repertoire provides valuable candidates for further characterization of the gene functions in mollusc immunity.

  11. Biochemical and ultrastructural studies of the C-type lectin bovine conglutinin

    DEFF Research Database (Denmark)

    Andersen, Ove; Nielsen, E H; Storgaard, P;

    1992-01-01

    The aim of this study was to correlate the supramolecular organization of conglutinin (BK) with its primary and tertiary structure and to gain more knowledge of functionally important regions of the molecule. BK analyzed by SDS-PAGE under standard reducing conditions (40 mM DTT) showed a major ba...

  12. Glycan and lectin biosensors

    Science.gov (United States)

    Belický, Štefan; Katrlík, Jaroslav

    2016-01-01

    A short description about the importance of glycan biorecognition in physiological (blood cell type) and pathological processes (infections by human and avian influenza viruses) is provided in this review. Glycans are described as much better information storage media, compared to proteins or DNA, due to the extensive variability of glycan structures. Techniques able to detect an exact glycan structure are briefly discussed with the main focus on the application of lectins (glycan-recognising proteins) in the specific analysis of glycans still attached to proteins or cells/viruses. Optical, electrochemical, piezoelectric and micromechanical biosensors with immobilised lectins or glycans able to detect a wide range of analytes including whole cells/viruses are also discussed. PMID:27365034

  13. Ureaplasma urealyticum binds mannose-binding lectin.

    Science.gov (United States)

    Benstein, Barbara D; Ourth, Donald D; Crouse, Dennis T; Shanklin, D Radford

    2004-10-01

    Mannose-binding C-type lectin (MBL) is an important component of innate immunity in mammals. Mannose-binding lectin (MBL), an acute phase protein, acts as an opsonin for phagocytosis and also activates the mannan-binding lectin complement pathway. It may play a particularly significant role during infancy before adequate specific protection can be provided by the adaptive immune system. Ureaplasma urealyticum has been linked to several diseases including pneumonia and chronic lung disease (CLD) in premature infants. We therefore investigated the ability of U. urealyticum to bind MBL. A guinea pig IgG anti-rabbit-MBL antiserum was produced. An immunoblot (dot-blot) assay done on nitrocellulose membrane determined that the anti-MBL antibody had specificity against both rabbit and human MBL. Pure cultures of U. urealyticum, serotype 3, were used to make slide preparations. The slides containing the organisms were then incubated with nonimmune rabbit serum containing MBL. Ureaplasma was shown to bind rabbit MBL with an immunocytochemical assay using the guinea pig IgG anti-rabbit MBL antiserum. Horseradish peroxidase (HRP)-labeled anti-guinea pig IgG was used to localize the reaction. The anti-MBL antiserum was also used in an immunocytochemical assay to localize U. urealyticum in histological sections of lungs from mice specifically infected with this organism. The same method also indicated binding of MBL by ureaplasma in human lung tissue obtained at autopsy from culture positive infants. Our results demonstrate that ureaplasma has the capacity to bind MBL. The absence of MBL may play a role in the predisposition of diseases related to this organism.

  14. Toxicity and Binding Profile of Lectins from the Genus Canavalia on Brine Shrimp

    Directory of Open Access Journals (Sweden)

    Francisco Vassiliepe Sousa Arruda

    2013-01-01

    Full Text Available Lectins are sugar-binding proteins widely distributed in nature with many biological functions. Although many lectins have a remarkable biotechnological potential, some of them can be cytotoxic. Thus, the aim of this study was to assess the toxicity of five lectins, purified from seeds of different species of Canavalia genus. In order to determine the toxicity, assays with Artemia nauplii were performed. In addition, a fluorescence assay was carried out to evaluate the binding of lectins to Artemia nauplii. In order to verify the relationship between the structure of lectins and their cytotoxic effect, structural analysis was carried out to evaluate the volume of the carbohydrate recognition domain (CRD of each lectin. The results showed that all lectins exhibited different toxicities and bound to a similar area in the digestive tract of Artemia nauplii. Concerning the structural analysis, differences in spatial arrangement and volume of CRD may explain the variation of the toxicity exhibited by each lectin. To this date, this is the first study that establishes a link between toxicity and structure of CRD from Diocleinae lectins.

  15. Toxicity and binding profile of lectins from the Genus canavalia on brine shrimp.

    Science.gov (United States)

    Arruda, Francisco Vassiliepe Sousa; Melo, Arthur Alves; Vasconcelos, Mayron Alves; Carneiro, Romulo Farias; Barroso-Neto, Ito Liberato; Silva, Suzete Roberta; Pereira-Junior, Francisco Nascimento; Nagano, Celso Shiniti; Nascimento, Kyria Santiago; Teixeira, Edson Holanda; Saker-Sampaio, Silvana; Sousa Cavada, Benildo; Sampaio, Alexandre Holanda

    2013-01-01

    Lectins are sugar-binding proteins widely distributed in nature with many biological functions. Although many lectins have a remarkable biotechnological potential, some of them can be cytotoxic. Thus, the aim of this study was to assess the toxicity of five lectins, purified from seeds of different species of Canavalia genus. In order to determine the toxicity, assays with Artemia nauplii were performed. In addition, a fluorescence assay was carried out to evaluate the binding of lectins to Artemia nauplii. In order to verify the relationship between the structure of lectins and their cytotoxic effect, structural analysis was carried out to evaluate the volume of the carbohydrate recognition domain (CRD) of each lectin. The results showed that all lectins exhibited different toxicities and bound to a similar area in the digestive tract of Artemia nauplii. Concerning the structural analysis, differences in spatial arrangement and volume of CRD may explain the variation of the toxicity exhibited by each lectin. To this date, this is the first study that establishes a link between toxicity and structure of CRD from Diocleinae lectins.

  16. A Lectin from Dioclea violacea Interacts with Midgut Surface of Lutzomyia migonei, Unlike Its Homologues, Cratylia floribunda Lectin and Canavalia gladiata Lectin

    Science.gov (United States)

    Monteiro Tínel, Juliana Montezuma Barbosa; Benevides, Melina Fechine Costa; Frutuoso, Mércia Sindeaux; Rocha, Camila Farias; Arruda, Francisco Vassiliepe Sousa; Vasconcelos, Mayron Alves; Pereira-Junior, Francisco Nascimento; Cajazeiras, João Batista; do Nascimento, Kyria Santiago; Martins, Jorge Luiz; Teixeira, Edson Holanda; Cavada, Benildo Sousa; dos Santos, Ricardo Pires; Lima Pompeu, Margarida Maria

    2014-01-01

    Leishmaniasis is a vector-borne disease transmitted by phlebotomine sand fly. Susceptibility and refractoriness to Leishmania depend on the outcome of multiple interactions that take place within the sand fly gut. Promastigote attachment to sand fly midgut epithelium is essential to avoid being excreted together with the digested blood meal. Promastigote and gut sand fly surface glycans are important ligands in this attachment. The purpose of the present study was to evaluate the interaction of three lectins isolated from leguminous seeds (Diocleinae subtribe), D-glucose and D-mannose-binding, with glycans on Lutzomyia migonei midgut. To study this interaction the lectins were labeled with FITC and a fluorescence assay was performed. The results showed that only Dioclea violacea lectin (DVL) was able to interact with midgut glycans, unlike Cratylia floribunda lectin (CFL) and Canavalia gladiata lectin (CGL). Furthermore, when DVL was blocked with D-mannose the interaction was inhibited. Differences of spatial arrangement of residues and volume of carbohydrate recognition domain (CRD) may be the cause of the fine specificity of DVL for glycans in the surface on Lu. migonei midgut. The findings in this study showed the presence of glycans in the midgut with glucose/mannose residues in its composition and these residues may be important in interaction between Lu. migonei midgut and Leishmania. PMID:25431778

  17. Lectin typing of Campylobacter concisus

    DEFF Research Database (Denmark)

    Aabenhus, Rune Munck; Hynes, Sean O; Permin, Henrik;

    2002-01-01

    A total of 44 clinical isolates and the type strain of the putative pathogen Campylobacter concisus were grouped based on their reactions with plant lectins. The optimized lectin typing system used C. concisus strains proteolytically pretreated and subsequently typed by using a panel of four...

  18. The lectin pathway of complement

    DEFF Research Database (Denmark)

    Ballegaard, Vibe Cecilie Diederich; Haugaard, Anna Karen; Garred, P;

    2014-01-01

    The pattern recognition molecules of the lectin complement pathway are important components of the innate immune system with known functions in host-virus interactions. This paper summarizes current knowledge of how these intriguing molecules, including mannose-binding lectin (MBL), Ficolin-1, -2...

  19. Recent advances in lectin-like oxidized low-density lipoprotein receptor-1 and atherosclerosis%血凝素样氧化低密度脂蛋白受体-1与动脉粥样硬化的研究进展

    Institute of Scientific and Technical Information of China (English)

    朱惠莲; 凌文华

    2004-01-01

    Lectin-like oxidized low density lipoprotein receptor-1 (LOX-1 } is a type-Ⅱ membrane protein belonging to the C-type lectin family molecules, which acts as a cell surface endocytosis receptor for atherogenic oxidized LDL (Ox-LDL). LOX-1 supports the binding internalization and proteolytic degradation of oxidized LDL, but not of significant amounts of acetylated LDL. LOX-1 is initially synthesized as a 40 kD precursor protein with N-linked high mannose-type carbohydrate, which is further glycosylated and processed into a 48-kD mature form. In vivo, endothelial cells that cover early therosclerotic lesions, intimal macrophages and smooth muscle cells in advanced atherosclerotic plaques express LOX-1. LOX-1 is cleaved at membrane proximal extracellular domain and released from the cell surface. Measurement of soluble LOX-1 in vivo may provide novel diagnostic strategy for the evaluation and prediction of atherosclerosis and vascular diseases.

  20. Lectins and Tetrahymena - A review.

    Science.gov (United States)

    Csaba, György

    2016-09-01

    The unicellular ciliate Tetrahymena is a complete organism, one of the most highly developed protozoans, which has specialized organelles performing each of the functions characteristic to the cells of higher ranked animals. It is also able to produce, store, and secrete hormones of higher ranked animals and also react to them. It produces lectins that can bind them and has functions, which are influenced by exogenous lectins. The review lists the observations on the relationship between lectins and Tetrahymena and try to construe them on the basis of the data, which are at our disposal. Considering the data, lectins can be used by Tetrahymena as materials for influencing conjugation, for stimulating hormone receptors, and by this, mimic the hormonal functions. Lectins can influence phagocytosis and movement of the cells as well as the cell division. As Tetrahymena can recognize both related and hostile cells by the help of lectins and surface sugars, it could be surmised a complex predator-prey system. This could determine the survival of the population as well as the nourishment conditions. When Tetrahymena is pathogenic, it can use lectins as virulence factors.

  1. Lectin complement protein Collectin 11 (CL-K1 and susceptibility to urinary schistosomiasis.

    Directory of Open Access Journals (Sweden)

    Justin S Antony

    2015-03-01

    Full Text Available Urinary Schistosomiasis is a neglected tropical disease endemic in many sub Saharan -African countries. Collectin Kidney 1 (CL-K1, encoded by COLEC11 on chromosome 2p25.3, a member of the vertebrate C-type lectin super family, has recently been identified as pattern-recognition molecule (PRR of the lectin complement pathway. CL-K1 is preferentially expressed in the kidneys, but also in other organs and it is considered to play a role in host defense to some infectious agents. Schistosome teguments are fucosylated and CL-K1 has, through its collagen-like domain, a high binding affinity to fucose.We utilized a Nigerian study group consisting of 167 Schistosoma haematobium infected individuals and 186 matched healthy subjects, and investigated the contribution of CL-K1 deficiency and of COLEC11 polymorphisms to infection phenotype. Higher CL-K1 serum levels were associated with decreased risk of schistosome infection (P corr = 0.0004. CL-K1 serum levels were differentially distributed between the COLEC11 genotypes and haplotypes observed. The non-synonymous variant p.R216H was associated with the occurrence of schistosomiasis (OR = 0.44, 95%CI = 0.22-0.72, P corr = 0.0004. The reconstructed COLEC11*TCCA haplotypes were associated with higher CL-K1 serum levels (P = 0.002 and with decreased schistosomiasis (OR = 0.38, 95%CI = 0.23-0.63, P corr = 0.0001.In agreement with findings from our earlier published study, our findings support the observation that CL-K1 and their functional variants may be host factors associated with protection in schistosomiasis and may be a useful marker for further investigations.

  2. Use of lectins in immunohematology

    Directory of Open Access Journals (Sweden)

    Ajit C Gorakshakar

    2016-01-01

    Full Text Available Lectins are carbohydrate binding proteins present in seeds of many plants, especially corals and beans, in fungi and bacteria, and in animals. Apart from their hemagglutinating property, a wide range of functions have been attributed to them. Their importance in the area of immunohematology is immense. They are used to detect specific red cell antigens, to activate different types of lymphocytes, in order to resolve problems related to polyagglutination and so on. The introduction of advanced biotechnological tools generates new opportunities to exploit the properties of lectins, which were not used earlier. Stem cell research is a very important area in transplant medicine. Certain lectins detect surface markers of stem cell. Hence, they are used to understand the developmental biology of stem cells. The role of various lectins in the areas of transfusion and transplant medicine is discussed in detail in this review.

  3. [Galectins, a class of unconventional lectins].

    Science.gov (United States)

    Advedissian, Tamara; Deshayes, Frédérique; Poirier, Françoise; Grandjean, Cyrille; Viguier, Mireille

    2015-05-01

    Galectins constitute a family of soluble animal lectins defined by their evolutionary conserved carbohydrate recognition domain and their affinity for β-galactosides containing glycoconjugates. Each galectin is characterized by a specific spatio-temporal distribution and a unique set of ligands and molecular partners. Interestingly, galectins are found both extracellularly and intracellularly and modulate various cellular processes. Knock-out mutant mice for galectins-1, 3 or 7 are viable but display a wide range of defects under various stress conditions. Indeed, galectins are multifunctional proteins involved in cell-cell and cell-extracellular matrix interactions, organization of membrane domains, cell signalling and also in intracellular trafficking, apoptosis, regulation of cell cycle. Galectins represent potential therapeutic targets, especially in the context of cancer and inflammatory diseases.

  4. Single CRD containing lectin from Macrobrachium rosenbergii (MrLec) participates in innate immunity against pathogen infections.

    Science.gov (United States)

    Huang, Xin; Li, Wen; Jin, Min; Ma, Fu-Tong; Huang, Ying; Shi, Yan-Ru; Zhao, Ling-Ling; Feng, Jin-Ling; Ren, Qian; Wang, Wen

    2016-04-01

    As a type of pattern-recognition proteins, lectins perform important functions in the innate immunity of crustaceans, including prawns. Although several reports showed that C-type lectin domain family (CLEC) importantly functions in host-pathogen interactions, limited research has focused on CLEC in Macrobrachium rosenbergii. In the present study, a new single CRD containing CLEC (designated as MrLec) was reported in freshwater prawns, M. rosenbergii. The full-length cDNA of MrLec consisted of 1027 bp with an open reading frame of 801 bp, which encoded a peptide of 266 amino acid residues. Genomic sequence for MrLec was also obtained from the M. rosenbergii, which contain 4 exons and 3 introns. MrLec was found to contain a single carbohydrate-recognition domain with an EPN motif. MrLec was ubiquitously distributed in various tissues of a normal prawn, particularly in the hepatopancreas and gills. MrLec expression in the gills was significantly upregulated after a challenge with Vibrio parahaemolyticus and downregulated at 24 h after MrLec RNA interference (MrLec-RNAi). The expression levels of some AMPs, including antilipopolysaccharide factor 1 (Alf1) and lysozyme 2 (Lyso2), also markedly decreased after MrLec-RNAi. Recombinant MrLec can agglutinate (Ca(2+)-dependent) and bind both Gram-negative and Gram-positive bacteria. Results suggested that MrLec participates in the recognition of invading pathogens and functions in the immune response of prawn against pathogen infections.

  5. Nkrp1 Family, from Lectins to Protein Interacting Molecules

    Directory of Open Access Journals (Sweden)

    Daniel Rozbeský

    2015-02-01

    Full Text Available The C-type lectin-like receptors include the Nkrp1 protein family that regulates the activity of natural killer (NK cells. Rat Nkrp1a was reported to bind monosaccharide moieties in a Ca2+-dependent manner in preference order of GalNac > GlcNAc >> Fuc >> Gal > Man. These findings established for rat Nkrp1a have been extrapolated to all additional Nkrp1 receptors and have been supported by numerous studies over the past two decades. However, since 1996 there has been controversy and another article showed lack of interactions with saccharides in 1999. Nevertheless, several high affinity saccharide ligands were synthesized in order to utilize their potential in antitumor therapy. Subsequently, protein ligands were introduced as specific binders for Nkrp1 proteins and three dimensional models of receptor/protein ligand interaction were derived from crystallographic data. Finally, for at least some members of the NK cell C-type lectin-like proteins, the “sweet story” was impaired by two reports in recent years. It has been shown that the rat Nkrp1a and CD69 do not bind saccharide ligands such as GlcNAc, GalNAc, chitotetraose and saccharide derivatives (GlcNAc-PAMAM do not directly and specifically influence cytotoxic activity of NK cells as it was previously described.

  6. Biological role of lectins: A review

    Directory of Open Access Journals (Sweden)

    K Kiran Kumar

    2012-01-01

    Full Text Available Lectins comprise a stracturally vary diverse class of proteins charecterized by their ability to selectively bind carbohydrate moieties of the glycoproteins of the cell surface. Lectins may be derived from plants, microbial or animal sources and may be soluble or membrane bound. Lectins is a tetramer made up of four nearly identical subunits. In human, lectins have been reported to cause food poisoning, hemolytic anemia, jaundice, digestive distress, protein and carbohydrate malabsorption and type I allergies. The present review focuses on the classification, structures, biological significance and application of lectins.

  7. Construction and immunogenicity of a codon-optimized Entamoeba histolytica Gal-lectin-based DNA vaccine.

    Science.gov (United States)

    Gaucher, Denis; Chadee, Kris

    2002-09-10

    Invasive amebiasis caused by Entamoeba histolytica is the third leading parasitic cause of mortality, and there are no vaccines available to help control the disease. The galactose-adherence lectin (Gal-lectin) is the parasite's major molecule allowing it to adhere to colonic mucin for colonization and to target cells for tissue destruction. It is immunodominant and is regarded as the most promising candidate molecule to be included in a subunit vaccine against amebiasis. In this study, we are reporting the construction of a codon-optimized DNA vaccine encoding a portion of the Gal-lectin heavy subunit that includes the carbohydrate recognition domain (CRD), and its in vivo testing in mice. The vaccine stimulated a Th1-type Gal-lectin-specific cellular immune response as well as the development of serum antibodies that recognized a recombinant portion of the heavy subunit, and that inhibited the adherence of trophozoites to target cells in vitro.

  8. Lectin-like Oxidized Low-Density Lipoprotein (LDL) Receptor (LOX-1): A Chameleon Receptor for Oxidized LDL.

    Science.gov (United States)

    Zeya, Bushra; Arjuman, Albina; Chandra, Nimai Chand

    2016-08-16

    LOX-1, one of the main receptors for oxLDL, is found mainly on the surface of endothelial cells. It is a multifacet 52 kDa type II transmembrane protein that structurally belongs to the C-type lectin family. It exists with short intracellular N-terminal and long extracellular C-terminal hydrophilic domains separated by a hydrophobic domain of 26 amino acids. LOX-1 acts like a bifunctional receptor either showing pro-atherogenicity by activating the NFκB-mediated down signaling cascade for gene activation of pro-inflammatory molecules or playing an atheroprotective agent by receptor-mediated uptake of oxLDL in the presence of an anti-inflammatory molecule like IL-10. Mildly, moderately, and highly oxidized LDL show their characteristic features upon LOX-1 activation and its ligand binding indenture. The polymorphic LOX-1 genes are intensively associated with increased susceptibility to myocardial diseases. The splicing variant LOX IN dimerizes with the native form of LOX-1 and protects cells from damage by oxidized LDL. In the developing field of regenerating medicine, LOX-1 is a potential target for therapeutic intervention.

  9. Isolation, functional, and partial biochemical characterization of galatrox, an acidic lectin from Bothrops atrox snake venom

    Institute of Scientific and Technical Information of China (English)

    Elaine de Paula Mendonca-Franqueiro; Eliane Candiani Arantes; Marcelo Dias-Baruffi; Suely Vilela Sampaio; Raquel de Melo Alves-Paiva; Marco Aurélio Sartim; Daniel Roberto Callejon; Helder Henrique Paiva; Gilmara Ausech Antonucci; José César Rosa; Adélia Cristina Oliveira Cintra; Jo(a)o José Franco

    2011-01-01

    Snake venom lectins have been studied in regard to their chemical structure and biological functions. However, little is known about lectins isolated from Bothrops atrox snake venom. We report here the isolation and partial functional and biochemical characterization of an acidic glycanbinding protein called galatrox from this venom. This lectin was purified by affinity chromatography using a lactosyl-sepharose column, and its homogeneity and molecular mass were evaluated by high-performance liquid chromatography, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. The purified galatrox was homogeneous and characterized as an acidic protein (pI 5.2) with a monomeric and dimeric molecular mass of 16.2 and 32.5 kDa, respectively. Alignment of N-terminal and internal amino acid sequences of galatrox indicated that this protein exhibits high homology to other C-type snake venom lectins. Galatrox showed optimal hemagglutinating activity at a concentration of 100 μg/ml and this effect was drastically inhibited by lactose, ethylenediaminetetraacetic acid, and heating, which confirmed galatrox's lectin activity. While galatrox failed to induce the same level of paw edema or mast cell degranulation as B. atrox crude venom, galatrox did alter cellular viability,which suggested that galatrox might contribute to venom toxicity by directly inducing cell death.

  10. Lectins as markers for blood grouping.

    Science.gov (United States)

    Khan, Fauzia; Khan, Rizwan H; Sherwani, Asma; Mohmood, Sameena; Azfer, Md A

    2002-12-01

    Lectins are unique proteins of varying biological importance. They are characterized by specific binding to carbohydrate residues, whether monosaccharides, disaccharides or polysaccharides. The sugar heads on the surface of the erythrocyte specify the different blood groups. Lectins, as an antigenic determinant of blood group, have come to be an important tool in the identification of different blood groups. A handful of lectins may be considered excellent reagents for anti-A, anti-B, anti-N etc, but the anti-A and anti-M are not yet regarded as commercially suitable antisera. Lectin from Vicia cracca has been proved to be a good anti-A, lectin from Dolichus biflorus can be used as anti-A1, and lectin from Griffonia simplicifolia as anti-B. Lectin from Vicia graminea is said to be a good typing reagent as Anti-N. On the other hand, the lectins involved in polyagglutination are absolutely essential as the reagent of choice and these cannot as yet be replaced by antibodies of any kind. Erythrocytes with exposed cryptantigens are significantly more sensitive to agglutination by certain lectins than by polyclonal antibodies. Peanut agglutinin (PNA), Polybrene, and Glycine max lectins are frequently used for the identification of different cryptantigens. The application of lectins as an anti-B reagent has proven to be as useful as human polyclonal or mouse monoclonal antibodies. Besides their specificity, lectins are excellent reagents because of their lower cost and indigenous production. The importance of various lectins used as markers for blood grouping is discussed.

  11. Human neutrophil migration and activation by BJcuL, a galactose binding lectin purified from Bothrops jararacussu venom

    Directory of Open Access Journals (Sweden)

    Fernandes Luiz

    2011-01-01

    Full Text Available Abstract Background Neutrophil migration to an inflamed site constitutes the first line of the innate immune response against invading microorganisms. Given the crucial role of endogenous lectins in neutrophil mobilization and activation, lectins from exogenous sources have often been considered as putative modulators of leukocyte function. Lectins purified from snake venom have been described as galactoside ligands that induce erythrocyte agglutination and platelet aggregation. This study evaluated human neutrophil migration and activation by C-type lectin BJcuL purified from Bothrops jararacussu venom. Results Utilizing fluorescence microscopy, we observed that biotinylated-BJcuL was evenly distributed on the neutrophil surface, selectively inhibited by D-galactose. Lectin was able to induce modification in the neutrophil morphology in a spherical shape for a polarized observed by optical microscopy and exposure to BJcuL in a Boyden chamber assay resulted in cell migration. After 30 minutes of incubation with BJcuL we found enhanced neutrophil functions, such as respiratory burst, zymozan phagocytosis and an increase in lissosomal volume. In addition, BJcuL delays late apoptosis neutrophils. Conclusion These results demonstrate that BJcuL can be implicated in a wide variety of immunological functions including first-line defense against pathogens, cell trafficking and induction of the innate immune response since lectin was capable of inducing potent neutrophil activation.

  12. [Lectins of Dryopteris Adans fern species].

    Science.gov (United States)

    Basheka, O V; Stetsenko, N M; Pogorila, N F

    1999-01-01

    Lectin activity of three ferns species (Dryopteris bushiana Fom., D. laeta (Kom.) C. Chr, D. pseudomas (Wollaston) Holub et Pouzar) has been studied. We used hemagglutination reaction albumin and globulin fractions of fronds and rhizomes extracts with rat erythrocytes. The frond extract of D. pseudomas have shown higher activity as compared with other extracts. The lectin activity of D. laeta leaves was absent. The rhizomes of all three fern species could be characterized as high activity. Based on lectin activity the species were placed as follows order: D. buschiana > D. pseudomas > D. laeta. The dependence with lectin activity and elements (Mn, Fe, Cu, Ni, Zn, Pb, Rb, Sr) content were not found.

  13. Expression of LSLCL, a new C-type lectin, is closely restricted, in bone marrow, to immature neutrophils.

    Science.gov (United States)

    Perrin, C; Bayle, J; Bannwarth, S; Michiels, J F; Heudier, P; Lefebvre, J C; Giordanengo, V

    2001-12-01

    In vitro, LSLCL is expressed by numerous myeloid, promyelocytic, and T or B lymphoblastoid cell lines. In vivo, LSLCL is strongly expressed in bone marrow and only faintly in lymphoid organs. We show here that, in bone marrow, LSLCL is detected: (i) concentrated in the cytoplasm of immature neutrophils but not in myeloblasts nor in mature neutrophils, (ii) in extracellular bone marrow fluid. Besides, numerous cDNAs, similar to LSLCL (identity of 93-99%), are found in 'expressed sequence tags' databases from various origins, mostly fetal and undifferentiated tumour tissues. Since LSLCL and various closely related cDNAs are expressed at definite stages of cellular maturation processes, we hypothesize that this class of proteins could play an important role in the control of cellular differentiation.

  14. Characterization of a gene family encoding SEA (sea-urchin sperm protein, enterokinase and agrin-domain proteins with lectin-like and heme-binding properties from Schistosoma japonicum.

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    Evaristus Chibunna Mbanefo

    Full Text Available BACKGROUND: We previously identified a novel gene family dispersed in the genome of Schistosoma japonicum by retrotransposon-mediated gene duplication mechanism. Although many transcripts were identified, no homolog was readily identifiable from sequence information. METHODOLOGY/PRINCIPAL FINDINGS: Here, we utilized structural homology modeling and biochemical methods to identify remote homologs, and characterized the gene products as SEA (sea-urchin sperm protein, enterokinase and agrin-domain containing proteins. A common extracellular domain in this family was structurally similar to SEA-domain. SEA-domain is primarily a structural domain, known to assist or regulate binding to glycans. Recombinant proteins from three members of this gene family specifically interacted with glycosaminoglycans with high affinity, with potential implication in ligand acquisition and immune evasion. Similar approach was used to identify a heme-binding site on the SEA-domain. The heme-binding mode showed heme molecule inserted into a hydrophobic pocket, with heme iron putatively coordinated to two histidine axial ligands. Heme-binding properties were confirmed using biochemical assays and UV-visible absorption spectroscopy, which showed high affinity heme-binding (K D = 1.605×10(-6 M and cognate spectroscopic attributes of hexa-coordinated heme iron. The native proteins were oligomers, antigenic, and are localized on adult worm teguments and gastrodermis; major host-parasite interfaces and site for heme detoxification and acquisition. CONCLUSIONS: The results suggest potential role, at least in the nucleation step of heme crystallization (hemozoin formation, and as receptors for heme uptake. Survival strategies exploited by parasites, including heme homeostasis mechanism in hemoparasites, are paramount for successful parasitism. Thus, assessing prospects for application in disease intervention is warranted.

  15. Cloning and expression of a mannose-binding jacalin-related lectin from leaves of Japanese cycad (Cycas revoluta Thunb.).

    Science.gov (United States)

    Haraguchi, Tomokazu; Nomura, Keiichi; Yagi, Fumio

    2006-09-01

    Cycad leaf lectin (CRLL), a mannose-recognizing jacalin-related lectin (mJRL), was first cloned as a gymnosperm lectin and expressed. The cDNA sequence of CRLL (DDBJ, accession no. AB198328), coding 291 amino acid residues, has a tandem repeat of about 150 amino acids divided into N- and C-terminal domains as Japanese chestnut mJRL. Sequence alignment showed deletion and insertion of the sequence, and its putative carbohydrate-binding sites showed some differences from other JRLs. PCR analysis showed that this lectin was expressed in the cycad leaf but not in the root or seed. Recombinant CRLL (rCRLL) was expressed in Escherichia coli and purified by affinity chromatography after refolding procedures. Properties of active rCRLL appeared to be almost the same as those of native CRLL.

  16. Structural characterization of coagulant Moringa oleifera Lectin and its effect on hemostatic parameters.

    Science.gov (United States)

    Luz, Luciana de Andrade; Silva, Mariana Cristina Cabral; Ferreira, Rodrigo da Silva; Santana, Lucimeire Aparecida; Silva-Lucca, Rosemeire Aparecida; Mentele, Reinhard; Oliva, Maria Luiza Vilela; Paiva, Patricia Maria Guedes; Coelho, Luana Cassandra Breitenbach Barroso

    2013-07-01

    Lectins are carbohydrate recognition proteins. cMoL, a coagulant Moringa oleifera Lectin, was isolated from seeds of the plant. Structural studies revealed a heat-stable and pH resistant protein with 101 amino acids, 11.67 theoretical pI and 81% similarity with a M. oleifera flocculent protein. Secondary structure content was estimated as 46% α-helix, 12% β-sheets, 17% β-turns and 25% unordered structures belonging to the α/β tertiary structure class. cMoL significantly prolonged the time required for blood coagulation, activated partial thromboplastin (aPTT) and prothrombin times (PT), but was not so effective in prolonging aPTT in asialofetuin presence. cMoL acted as an anticoagulant protein on in vitro blood coagulation parameters and at least on aPTT, the lectin interacted through the carbohydrate recognition domain.

  17. The areas of application for plant lectins

    Directory of Open Access Journals (Sweden)

    Melnykova N. M.

    2013-09-01

    Full Text Available Lectins, in particular from plants, are proteins of non-immune origin that are able to bind carbohydrates with high specificity. Due to their properties, phytolectins are of great interest in practical applications. They were shown to play an important role in forming strategies for treatment of disease including cancer and HIV. Plant lectins are an important tool in glycomic studies. Plant lectins with fungicidal and insecticidal activities are used in transgenic technologies to increase plant resistance to pests and phytopathogens. The introduction of lectin-like kinases genes into plant genome was shown to be perspective way to protect plants against environmental stresses and regulate plant growth. Engineering of phytolectins allows obtaining molecules with known carbohydrate specificity that can be applied in various areas. The studies are underway with the aim of design of lectin-based drug delivery systems as well as the pharmaceutical drugs containing plant lectins. Because of the ability of phytolectins to bind to different substances they can be more widely used in the future. The review focuses on current data and future possibilities in the application of plant lectins.

  18. Agglutination of Helicobacter pylori coccoids by lectins

    Institute of Scientific and Technical Information of China (English)

    Mar Mar Khin; Jie Song Hua; Hah Cong Ng; Bow Ho; Torkel Wadstrorr

    2000-01-01

    AIM To study the agglutination pattern of Helicobacter pylori coccoid and spiral forms.METHODS Assays of agglutination and agglutination inhibition were applied using fifteen commercial lectins. RESULTS Strong agglutination was observed with mannose-specific Concanavalin A (Con A ),fucose-specific Tetragonolobus purpureas ( Lotus A ) and N-acetyl glucosamine-specific Triticum vulgaris (WGA) lectins. Mannose and fucose specific lectins were reactive with all strains of H. pylori coccoids as compared to the spirals. Specific carbohydrates, glycoproteins and mucin were shown to inhibit H. pylori lectin-agglutination reactions. Pre-treatment of the bacterial cells with formalin and sulphuric acid did not alter the agglutination patterns with lectins. However, sodium periodate treatment of bacterial cells were shown to inhibit agglutination reaction with Con A, Lotus A and WGA lectins. On the contrary, enzymatic treatment of coccoids and spirals did not show marked inhibition of H. pylori-lectin agglutination. Interestingly, heating of H.pylori cells at 60℃ for 1 hour was shown to augment the agglutination with all of the lectins tested. CONCLUSION The considerable differences in lectin agglutination patterns seen among the two differentiated forms of H. pylori might be attributable to the structural changes during theevents of morphological transformation,resulting in exposing or masking some of the sugar residues on the cell surface. Possibility of various sugar residues on the cell wall of the coccoids may allow them to bind to different carbohydrate receptors on gastric mucus and epithelial cells. The coccoids with adherence characteristics like the spirals could aid in the pathogenic process of Helicobacter infection.This may probably lead to different clinical outcome of H. pylori associated gastroduodenal disease.

  19. Assessing biosafety of GM plants containing lectins

    DEFF Research Database (Denmark)

    Poulsen, Morten; Pedersen, Jan W.

    2010-01-01

    of the lectins that are potentially useful for insect resistance will pose no health risk in genetically modified (GM) plants. Since some lectins are known for their toxicity to humans, the insertion of lectin genes in food crop plants will have to be assessed carefully. It is expected that in some cases...... there will be a need to perform animal tests of such GM plants in order to eliminate any uncertainties about potential safety issues for these plants. A 90-day study designed and optimized for this purpose is suggested as one way to cope with these uncertainties....

  20. The heparin-binding site in tetranectin is located in the N-terminal region and binding does not involve the carbohydrate recognition domain

    DEFF Research Database (Denmark)

    Lorentsen, R H; Graversen, Jonas Heilskov; Caterer, N R

    2000-01-01

    in three exons. Exon 3 encodes the carbohydrate recognition domain, which binds to kringle 4 in plasminogen at low levels of Ca(2+). Exon 2 encodes an alpha-helix, which is necessary and sufficient to govern the trimerization of tetranectin by assembling into a triple-helical coiled-coil structural element......Tetranectin is a homotrimeric plasma and extracellular-matrix protein that binds plasminogen and complex sulphated polysaccharides including heparin. In terms of primary and tertiary structure, tetranectin is related to the collectin family of Ca(2+)-binding C-type lectins. Tetranectin is encoded....... Here we show that the heparin-binding site in tetranectin resides not in the carbohydrate recognition domain but within the N-terminal region, comprising the 16 amino acid residues encoded by exon 1. In particular, the lysine residues in the decapeptide segment KPKKIVNAKK (tetranectin residues 6...

  1. Lectin Complement Pathway Proteins in Healthy Individuals

    DEFF Research Database (Denmark)

    Troldborg, Anne; Hansen, Annette; Hansen, Søren W K

    2017-01-01

    Since the discovery of the lectin pathway of complement activation, numerous clinical cohorts have been examined for one or more of the proteins, with the intention of uncovering the functions of the proteins or with the aim of discovering new biomarkers or diagnostic tools. To unveil the abnormal......, it is pivotal to know the normal. Our aim was to describe the concentrations of the eleven known proteins of the lectin pathway in serum and plasma and to uncover possible gender differences, age and diurnal variations, which must be taken into account for investigations in different cohorts. We examined...... the concentrations of all lectin pathway proteins (mannan-binding lectin (MBL), H-ficolin, L-ficolin, M-ficolin, collectin-K1, collectin-L1, MBL-associated serine protease 2 (MASP-2), MASP-3, MBL associated protein of 44 kDa (MAp44) and MAp19 in 300 Danish blood donors in serum and EDTA plasma in established assays...

  2. Lectin binding in normal donkey eyeball

    Directory of Open Access Journals (Sweden)

    Khaled Aly

    2013-10-01

    Full Text Available In the present study, the distribution of various sugar residues in the eyeball tissues of sexually mature donkey was examined by employing fluorescein isothiocyanate-conjugated lectins. Our results revealed the presence of mannose (labeled by lectins ConA, galactose (labeled by PNA, GSAI, ECA, GalNAc (labeled by SBA, VVA, and GlcNAc (labeled by WGA residues in the donkey ocular tissues. The epithelium and stroma of the ocular tissues were labeled with mannose (ConA and GlcNAc (WGA binding lectins. Binding sites for WGA and PNA to the rod and cone cells of the retina were evident. The lectins Con A, WGA and GSAI are bound strongly to the endothelium of blood vessels and to smooth muscle cells of the iris. In conclusion, the findings of the present study clearly indicate that the donkey eyeball contains a wide range of glycoconjugates (bearing mannosyl, galactosyl and glucosly residues, and it lacks fucosyl residues.

  3. Lectin interactions with alpha-galactosylated xenoantigens

    DEFF Research Database (Denmark)

    Kirkeby, Svend; Moe, Dennis

    2002-01-01

    alpha-Galactosylated xenoantigens (Galalpha1-3Galbeta1-4GlcNAcbeta1 and Galalpha1-3Galbeta1-4GlcNAcbeta1-3Galbeta1-4Glc) are often detected with the alpha-Gal specific lectin Griffonia simplicifolia 1 isolectin B4 (GS1 B4). However, this lectin exhibits a broad and variable specificity for carboh...

  4. Porifera Lectins: Diversity, Physiological Roles and Biotechnological Potential.

    Science.gov (United States)

    Gardères, Johan; Bourguet-Kondracki, Marie-Lise; Hamer, Bojan; Batel, Renato; Schröder, Heinz C; Müller, Werner E G

    2015-08-07

    An overview on the diversity of 39 lectins from the phylum Porifera is presented, including 38 lectins, which were identified from the class of demosponges, and one lectin from the class of hexactinellida. Their purification from crude extracts was mainly performed by using affinity chromatography and gel filtration techniques. Other protocols were also developed in order to collect and study sponge lectins, including screening of sponge genomes and expression in heterologous bacterial systems. The characterization of the lectins was performed by Edman degradation or mass spectrometry. Regarding their physiological roles, sponge lectins showed to be involved in morphogenesis and cell interaction, biomineralization and spiculogenesis, as well as host defense mechanisms and potentially in the association between the sponge and its microorganisms. In addition, these lectins exhibited a broad range of bioactivities, including modulation of inflammatory response, antimicrobial and cytotoxic activities, as well as anticancer and neuromodulatory activity. In view of their potential pharmacological applications, sponge lectins constitute promising molecules of biotechnological interest.

  5. Lectin affinity chromatography of glycolipids

    Energy Technology Data Exchange (ETDEWEB)

    Torres, B.V.; Smith, D.F.

    1987-05-01

    Since glycolipids (GLs) are either insoluble or form mixed micelles in water, lectin affinity chromatography in aqueous systems has not been applied to their separation. They have overcome this problem by using tetrahydrofuran (THF) in the mobile phase during chromatography. Affinity columns prepared with the GalNAc-specific Helix pomatia agglutinin (HPA) and equilibrated in THF specifically bind the (/sup 3/H)oligosaccharide derived from Forssman GL indicating that the immobilized HPA retained its carbohydrate-binding specificity in this solvent. Intact Forssman GL was bound by the HPA-column equilibrated in THF and was specifically eluted with 0.1 mg/ml GalNAc in THF. Purification of the Forssman GL was achieved when a crude lipid extract of sheep erythrocyte membranes was applied to the HPA-column in THF. Non-specifically bound GLs were eluted from the column using a step gradient of aqueous buffer in THF, while the addition of GalNAc was required to elute the specifically bound GLs. Using this procedure the A-active GLs were purified from a crude lipid extract of type A human erythrocytes in a single chromatographic step. The use of solvents that maintain carbohydrate-binding specificity and lipid solubility will permit the application of affinity chromatography on immobilized carbohydrate-binding proteins to intact GLs.

  6. Burkholderia cenocepacia BC2L-C is a super lectin with dual specificity and proinflammatory activity.

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    Ondřej Sulák

    2011-09-01

    Full Text Available Lectins and adhesins are involved in bacterial adhesion to host tissues and mucus during early steps of infection. We report the characterization of BC2L-C, a soluble lectin from the opportunistic pathogen Burkholderia cenocepacia, which has two distinct domains with unique specificities and biological activities. The N-terminal domain is a novel TNF-α-like fucose-binding lectin, while the C-terminal part is similar to a superfamily of calcium-dependent bacterial lectins. The C-terminal domain displays specificity for mannose and l-glycero-d-manno-heptose. BC2L-C is therefore a superlectin that binds independently to mannose/heptose glycoconjugates and fucosylated human histo-blood group epitopes. The apo form of the C-terminal domain crystallized as a dimer, and calcium and mannose could be docked in the binding site. The whole lectin is hexameric and the overall structure, determined by electron microscopy and small angle X-ray scattering, reveals a flexible arrangement of three mannose/heptose-specific dimers flanked by two fucose-specific TNF-α-like trimers. We propose that BC2L-C binds to the bacterial surface in a mannose/heptose-dependent manner via the C-terminal domain. The TNF-α-like domain triggers IL-8 production in cultured airway epithelial cells in a carbohydrate-independent manner, and is therefore proposed to play a role in the dysregulated proinflammatory response observed in B. cenocepacia lung infections. The unique architecture of this newly recognized superlectin correlates with multiple functions including bacterial cell cross-linking, adhesion to human epithelia, and stimulation of inflammation.

  7. NMR investigations of protein-carbohydrate interactions : Studies on the relevance of Trp/Tyr variations in lectin binding sites as deduced from titration microcalorimetry and NMR studies on hevein domains. Determination of the NMR structure of the complex between pseudohevein and N,N ',N ''-triacetylchitotriose

    NARCIS (Netherlands)

    Asensio, JL; Siebert, HC; von der Lieth, CW; Laynez, J; Bruix, M; Soedjanaamadja, UM; Beintema, JJ; Canada, FJ; Gabius, HJ; Jimenez-Barbero, J

    2000-01-01

    Model studies on lectins and their interactions with carbohydrate ligands in solution are essential to gain insights into the driving forces for complex formation and to optimize programs for computer simulations. The specific interaction of pseudohevein with N,N',N"-triacetylchitotriose has been an

  8. Binding of Galanthus nivalis lectin to Chlamydia trachomatis and inhibition of in vitro infection.

    Science.gov (United States)

    Amin, K; Beillevaire, D; Mahmoud, E; Hammar, L; Mårdh, P A; Fröman, G

    1995-10-01

    A glycoprotein present in Chlamydia trachomatis, serotype L1, elementary bodies (EBs) was earlier found to bind the lectin from Galanthus nivalis (GNA). In the present paper we investigate the interaction of GNA with chlamydial EBs and its effect on in vitro infectivity. The binding affinity was studied with 125I-GNA lectin. Within 15 min about 80% maximal binding was obtained. The chlamydia-GNA interaction was inhibited by alpha-methylmannoside, causing a decrease of about 50% at 1 mM. Curve fit analyses indicated two types of binding sites for GNA on the EBs. The affinity to these differed by a factor of 15. The influence of the lectin on the ability of C. trachomatis to infect McCoy cells was also investigated. There was a GNA-dependent inhibition with a 50% reduction in the number of intracellular inclusions at 0.2 microM of the lectin. The findings indicate the presence of terminal mannose structures on the chlamydial surface at or in the proximity of the cell-binding domains. Mannose-binding proteins of eukaryotic cells could be important for the initial uptake of EBs.

  9. Rapid identification of Mycobacterium species by lectin agglutination.

    Science.gov (United States)

    Athamna, Abed; Cohen, Dani; Athamna, Muhammad; Ofek, Itzhak; Stavri, Henriette

    2006-05-01

    The purpose of the present study is to explore the possibility that plant lectins can be used for the development of rapid and inexpensive technique for differentiation of mycobacterial species. The method is based on interaction between mycobacteria and lectins as visualized by agglutination in a microtiter plate. We employed 18 mycobacterium species and determined the minimal lectin concentration (MLC) of 23 different lectins. For some of the bacteria as a high as 1000 microg/ml of one or more lectins were required to induce agglutination, while for other strains as low as 1.95 microg/ml of the lectin were needed. A unique pattern of agglutination was observed for each species over a range of 62-1000 microg/ml lectin concentrations. There were little or no variations in MLC within strains (intraspecies) of each of two species tested. In contrast, there were marked interspecies variations in MLC. Analysis of the MLC showed that the highest score of interspecies differences with 23 lectins was obtained at 125 microg/ml lectin concentration. At this concentration it was found that the pattern of agglutinations with only two lectins was sufficient to differentiate mycobacterium species from each other. Because the bacteria-lectin interaction is adaptable to various methods of visualization, our findings may set the stage for developing a rapid and reliable tool to differentiate mycobacterium species.

  10. Glycan microarray analysis of the carbohydrate-recognition specificity of native and recombinant forms of the lectin ArtinM.

    Science.gov (United States)

    Liu, Y; Cecílio, N T; Carvalho, F C; Roque-Barreira, M C; Feizi, T

    2015-12-01

    This article contains data related to the researc.h article entitled "Yeast-derived ArtinM shares structure, carbohydrate recognition, and biological effects with native ArtinM" by Cecílio et al. (2015) [1]. ArtinM, a D-mannose-binding lectin isolated from the seeds of Artocarpus heterophyllus, exerts immunomodulatory and regenerative activities through its Carbohydrate Recognition Domain (CRD) (Souza et al., 2013; Mariano et al., 2014 [2], [3]). The limited availability of the native lectin (n-ArtinM) led us to characterize a recombinant form of the protein, obtained by expression in Saccharomyces cerevisiae (y-ArtinM). We compared the carbohydrate-binding specificities of y-ArtinM and n-ArtinM by analyzing the binding of biotinylated preparations of the two lectin forms using a neoglycolipid (NGL)-based glycan microarray. Data showed that y-ArtinM mirrored the specificity exhibited by n-ArtinM.

  11. Mushroom Lectins: Specificity, Structure and Bioactivity Relevant to Human Disease

    Directory of Open Access Journals (Sweden)

    Mohamed Ali Abol Hassan

    2015-04-01

    Full Text Available Lectins are non-immunoglobulin proteins that bind diverse sugar structures with a high degree of selectivity. Lectins play crucial role in various biological processes such as cellular signaling, scavenging of glycoproteins from the circulatory system, cell–cell interactions in the immune system, differentiation and protein targeting to cellular compartments, as well as in host defence mechanisms, inflammation, and cancer. Among all the sources of lectins, plants have been most extensively studied. However, more recently fungal lectins have attracted considerable attention due to their antitumor, antiproliferative and immunomodulatory activities. Given that only 10% of mushroom species are known and have been taxonomically classified, mushrooms represent an enormous unexplored source of potentially useful and novel lectins. In this review we provide an up-to-date summary on the biochemical, molecular and structural properties of mushroom lectins, as well as their versatile applications specifically focusing on mushroom lectin bioactivity.

  12. Crosstalk between innate and adaptive immune responses to infectious bronchitis virus after vaccination and challenge of chickens varying in serum mannose-binding lectin concentrations

    DEFF Research Database (Denmark)

    Juul-Madsen, Helle R.; Norup, Liselotte R.; Jørgensen, Poul Henrik;

    2011-01-01

    Mannose-binding lectin (MBL), a C-type collectin with structural similarities to C1q, is an innate pattern-recognition molecule that is sequestered to sites of inflammation and infections. MBL selectively binds distinct chemical patterns, including carbohydrates expressed on all kinds of pathogens...... levels. These data demonstrate that MBL is involved in the regulation of the adaptive immune response to IBV....

  13. Plant lectin can target receptors containing sialic acid, exemplified by podoplanin, to inhibit transformed cell growth and migration.

    Directory of Open Access Journals (Sweden)

    Jhon Alberto Ochoa-Alvarez

    Full Text Available Cancer is a leading cause of death of men and women worldwide. Tumor cell motility contributes to metastatic invasion that causes the vast majority of cancer deaths. Extracellular receptors modified by α2,3-sialic acids that promote this motility can serve as ideal chemotherapeutic targets. For example, the extracellular domain of the mucin receptor podoplanin (PDPN is highly O-glycosylated with α2,3-sialic acid linked to galactose. PDPN is activated by endogenous ligands to induce tumor cell motility and metastasis. Dietary lectins that target proteins containing α2,3-sialic acid inhibit tumor cell growth. However, anti-cancer lectins that have been examined thus far target receptors that have not been identified. We report here that a lectin from the seeds of Maackia amurensis (MASL with affinity for O-linked carbohydrate chains containing sialic acid targets PDPN to inhibit transformed cell growth and motility at nanomolar concentrations. Interestingly, the biological activity of this lectin survives gastrointestinal proteolysis and enters the cardiovascular system to inhibit melanoma cell growth, migration, and tumorigenesis. These studies demonstrate how lectins may be used to help develop dietary agents that target specific receptors to combat malignant cell growth.

  14. IDENTIFICATION OF LECTINS OF ZEA MAYS RAW MATERIAL AND THE STUDY OF LECTIN ACTIVITY

    Directory of Open Access Journals (Sweden)

    Karpiuk UV

    2013-03-01

    Full Text Available The aime of the study was to identify lectins in the Zea mays raw material: roots, stems, heads, leaves and corn silk and study their activity. Lectins activity has been studied using the biological method of ratuserytroagglutination. This method is based on formation of aggregates of lectins and rats erythrocytes. The activity unit was the floor amount of lectins that agglutinate erythrocytes. The protein nature of extracts that agglutinate has been determined using Bradford method. The lectins activity of Zea mays roots was 6,21±0,11 unit/mg of protein; of heads – 2,61±0,17 unit/mg of protein; of leaves – 0,62 ±0,05 unit/mg of protein; of corn silk – 1,06±0,08 unit/mg of protein; of stems – 0,97±0,09 unit/mg of protein. The greatest lectins activity was in leaves, stems and corn silk.

  15. Three-dimensional structure of lectin from Dioclea violacea and comparative vasorelaxant effects with Dioclea rostrata

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, B.A.M.; Bezerra, M.J.B.; Bezerra, G.A.; Alencar, K.L.L.; Nascimento, K.S.; Naganao, C.S.; Sampaio, A.H.; Cavada, B.S. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil); Delatorre, P. [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil); Rodrigues, N.V.; Pires, A.F.; Assreuy, A.M.S. [Universidade Estadual do Ceara (UECE), Fortaleza, CE (Brazil); Marins, J.L. [Universidade Federal de Pelotas (UFPel), Pelotas, RS (Brazil)

    2012-07-01

    Full text: Lectins are a structural heterogeneous group of proteins possessing at least one non-catalytic domain that binds reversibly to a specific mono or oligosaccharide. Diocleinae lectins exhibit glucose/mannose monosaccharide binding specificity and studies of their chemical and physicochemical properties revealed a high degree of identity in their amino acid sequences and three dimensional structures. This study investigated structural/functional relationships between lectins obtained from Dioclea violacea (DVL) and Dioclea rostrata (DRL). The purified lectin (DVL) was solubilized in 20 mM Tris-HCl pH 7.6 with 5 mM CaCl{sub 2} and MnCl{sub 2} buffer and incubated during one hour before the crystallization experiments with the ligand X-Man (5-bromo-4-chloro-3-indolyl-{alpha}-D-mannose) at 3 mM. Crystals of DVL grew in condition 33 of Crystal Screen I (4M Sodium formate) and belong to the orthorhombic space group I222. The structure of DVL at 2.6 resolution was obtained by molecular replacement using the coordinates of DRL (PDB code 2ZBJ), after the last refinement the structure presented R factor of 0.23 and R free of 0.27. The crystal structures reveal differences between them and could be related to relaxant activity. The conformation of residues HIS51, HIS131 and GLU205 and others positioned at CRD lead to different lectin binding activities. In fact, the pocket in DVL is small and deep and promotes weak interaction with carbohydrates, while DRL pocket is large and shallow, allowing strong interaction between CRD and sugars. This can explain why DVL and DRL elicited different degrees of aorta relaxation showing maximal effects of 43 % and 96 %, respectively. (author)

  16. Animal lectins: potential receptors for ginseng polysaccharides

    Directory of Open Access Journals (Sweden)

    So Hee Loh

    2017-01-01

    Full Text Available Panax ginseng Meyer, belonging to the genus Panax of the family Araliaceae, is known for its human immune system-related effects, such as immune-boosting effects. Ginseng polysaccharides (GPs are the responsible ingredient of ginseng in immunomodulation, and are classified as acidic and neutral GPs. Although GPs participate in various immune reactions including the stimulation of immune cells and production of cytokines, the precise function of GPs together with its potential receptor(s and their signal transduction pathways have remained largely unknown. Animal lectins are carbohydrate-binding proteins that are highly specific for sugar moieties. Among many different biological functions in vivo, animal lectins especially play important roles in the immune system by recognizing carbohydrates that are found exclusively on pathogens or that are inaccessible on host cells. This review summarizes the immunological activities of GPs and the diverse roles of animal lectins in the immune system, suggesting the possibility of animal lectins as the potential receptor candidates of GPs and giving insights into the development of GPs as therapeutic biomaterials for many immunological diseases.

  17. BAD-lectins: boronic acid-decorated lectins with enhanced binding affinity for the selective enrichment of glycoproteins.

    Science.gov (United States)

    Lu, Ying-Wei; Chien, Chih-Wei; Lin, Po-Chiao; Huang, Li-De; Chen, Chang-Yang; Wu, Sz-Wei; Han, Chia-Li; Khoo, Kay-Hooi; Lin, Chun-Cheng; Chen, Yu-Ju

    2013-09-03

    The weak and variable binding affinities exhibited by lectin-carbohydrate interactions have often compromised the practical utility of lectin in capturing glycoproteins for glycoproteomic applications. We report here the development and applications of a new type of hybrid biomaterial, namely a boronic acid-decorated lectin (BAD-lectin), for efficient bifunctional glycoprotein labeling and enrichment. Our binding studies showed an enhanced affinity by BAD-lectin, likely to be mediated via the formation of boronate ester linkages between the lectin and glycan subsequent to the initial recognition process and thus preserving its glycan-specificity. Moreover, when attached to magnetic nanoparticles (BAD-lectin@MNPs), 2 to 60-fold improvement on detection sensitivity and enrichment efficiency for specific glycoproteins was observed over the independent use of either lectin or BA. Tested at the level of whole cell lysates for glycoproteomic applications, three different types of BAD-lectin@MNPs exhibited excellent specificities with only 6% overlapping among the 295 N-linked glycopeptides identified. As many as 236 N-linked glycopeptides (80%) were uniquely identified by one of the BAD-lectin@MNPs. These results indicated that the enhanced glycan-selective recognition and binding affinity of BAD-lectin@MNPs will facilitate a complementary identification of the under-explored glycoproteome.

  18. The search for lectin isolated from the mycelial cultures of Laetiporus sulphureus

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    Grażyna Końska

    2014-08-01

    Full Text Available This study proved the presence of lectin in mycelial cultures of Laetiporus sulphureus. Lectin was excreted into the medium and its erythroagglutinating activity was not high. No active lectin was detected in hyphae using both extraction and immunofluorescence method. Comparative studies based on immunological methods indicate~ that the lectin synthesised in vitro differed from the lectin produced in fruit-bodies.

  19. C-type natriuretic peptide in prostate cancer

    DEFF Research Database (Denmark)

    Nielsen, Soeren Junge; Iversen, Peter; Rehfeld, Jens F.;

    2009-01-01

    C-type natriuretic peptide (CNP) is expressed in the male reproductive organs in pigs. To examine whether the human prostate also expresses the CNP gene, we measured CNP and N-terminal proCNP in prostate cancer tissue extracts and performed immunohistochemical biopsy staining. Additionally, pro......CNP-derived peptides were quantitated in plasma from patients with prostate cancer. Blood was collected from healthy controls and patients before surgery for localized prostate cancer. Tissue extracts were prepared from tissue biopsies obtained from radical prostatectomy surgery. N-terminal proCNP, proCNP (1...... demonstrated the presence of the peptides in prostatic epithelial cells. The N-terminal proCNP concentrations in plasma were marginally lower in patients with localized prostate cancer compared with control subjects [13.8 pmol/l (11.0-17.2) vs. 15.1 pmol/l (10.4-23.2), p=0.002] but not enough to justify...

  20. C-type natriuretic peptide and its precursor

    DEFF Research Database (Denmark)

    Lippert, Solvej; Iversen, Peter; Brasso, Klaus;

    2015-01-01

    AIM: Seminal plasma offer a more organ-specific matrix for markers in prostatic disease. We hypothesized that C-type natriuretic peptide (CNP) expression may constitute such a new target. METHODS: Patients with benign prostatic hyperplasia, clinically localized and metastatic prostate cancer were...... examined for CNP and CNP precursor (proCNP) concentrations in blood and seminal plasma. Furthermore, CNP and the CNP receptor (NPR-B) mRNA contents in tissue from prostate and seminal vesicles were analyzed by qPCR. RESULTS: CNP and NPR-B concentrations decreased with increasing tumor burden (p = 0.......0027 and p = 0.0096, respectively). In contrast, seminal plasma CNP and proCNP concentrations were markedly increased with increased tumor burden (p prostate cancer....

  1. Lectins, Interconnecting Proteins with Biotechnological/Pharmacological and Therapeutic Applications

    Science.gov (United States)

    Silva, Priscila Marcelino dos Santos

    2017-01-01

    Lectins are proteins extensively used in biomedical applications with property to recognize carbohydrates through carbohydrate-binding sites, which identify glycans attached to cell surfaces, glycoconjugates, or free sugars, detecting abnormal cells and biomarkers related to diseases. These lectin abilities promoted interesting results in experimental treatments of immunological diseases, wounds, and cancer. Lectins obtained from virus, microorganisms, algae, animals, and plants were reported as modulators and tool markers in vivo and in vitro; these molecules also play a role in the induction of mitosis and immune responses, contributing for resolution of infections and inflammations. Lectins revealed healing effect through induction of reepithelialization and cicatrization of wounds. Some lectins have been efficient agents against virus, fungi, bacteria, and helminths at low concentrations. Lectin-mediated bioadhesion has been an interesting characteristic for development of drug delivery systems. Lectin histochemistry and lectin-based biosensors are useful to detect transformed tissues and biomarkers related to disease occurrence; antitumor lectins reported are promising for cancer therapy. Here, we address lectins from distinct sources with some biological effect and biotechnological potential in the diagnosis and therapeutic of diseases, highlighting many advances in this growing field. PMID:28367220

  2. Lectins, Interconnecting Proteins with Biotechnological/Pharmacological and Therapeutic Applications

    Directory of Open Access Journals (Sweden)

    Luana Cassandra Breitenbach Barroso Coelho

    2017-01-01

    Full Text Available Lectins are proteins extensively used in biomedical applications with property to recognize carbohydrates through carbohydrate-binding sites, which identify glycans attached to cell surfaces, glycoconjugates, or free sugars, detecting abnormal cells and biomarkers related to diseases. These lectin abilities promoted interesting results in experimental treatments of immunological diseases, wounds, and cancer. Lectins obtained from virus, microorganisms, algae, animals, and plants were reported as modulators and tool markers in vivo and in vitro; these molecules also play a role in the induction of mitosis and immune responses, contributing for resolution of infections and inflammations. Lectins revealed healing effect through induction of reepithelialization and cicatrization of wounds. Some lectins have been efficient agents against virus, fungi, bacteria, and helminths at low concentrations. Lectin-mediated bioadhesion has been an interesting characteristic for development of drug delivery systems. Lectin histochemistry and lectin-based biosensors are useful to detect transformed tissues and biomarkers related to disease occurrence; antitumor lectins reported are promising for cancer therapy. Here, we address lectins from distinct sources with some biological effect and biotechnological potential in the diagnosis and therapeutic of diseases, highlighting many advances in this growing field.

  3. Production, purification, and capsid stability of rhinovirus C types.

    Science.gov (United States)

    Griggs, Theodor F; Bochkov, Yury A; Nakagome, Kazuyuki; Palmenberg, Ann C; Gern, James E

    2015-06-01

    The rhinovirus C (RV-C) were discovered in 2006 and these agents are an important cause of respiratory morbidity. Little is known about their biology. RV-C15 (C15) can be produced by transfection of recombinant viral RNA into cells and subsequent purification over a 30% sucrose cushion, even though yields and infectivity of other RV-C genotypes with this protocol are low. The goal of this study was to determine whether poor RV-C yields were due to capsid instability, and moreover, to develop a robust protocol suitable for the purification of many RV-C types. Capsid stability assays indicated that virions of RV-C41 (refractory to purification) have similar tolerance for osmotic and temperature stress as RV-A16 (purified readily), although C41 is more sensitive to low pH. Modification to the purification protocol by removing detergent increased the yield of RV-C. Addition of nonfat dry milk to the sucrose cushion increased the virus yield but sacrificed purity of the viral suspension. Analysis of virus distribution following centrifugation indicated that the majority of detectable viral RNA (vRNA) was found in pellets refractory to resuspension. Reduction of the centrifugal force with commiserate increase in spin-time improved the recovery of RV-C for both C41 and C2. Transfection of primary lung fibroblasts (WisL cells) followed by the modified purification protocol further improved yields of infectious C41 and C2. Described herein is a higher yield purification protocol suitable for RV-C types refractory to the standard purification procedure. The findings suggest that aggregation-adhesion problems rather than capsid instability influence RV-C yield during purification.

  4. Molecular dynamics simulations and MM-PBSA calculations of the lectin from snowdrop (Galanthus nivalis).

    Science.gov (United States)

    Liu, Zhen; Zhang, Yizheng

    2009-12-01

    Galanthus nivalis agglutinin (GNA), a mannose-specific lectin from snowdrop bulbs, is a member of the monocot mannose-specific lectin family and exhibits antiviral activity toward HIV. In the present study, molecular dynamics (MD) simulations were performed to study the interaction between GNA and its carbohydrate ligand over a specific time span. By analysis of the secondary structures, it was observed that the GNA conformation maintains rather stable along the trajectories and the high fluctuations were only centered on the carbohydrate recognition domains. Our MD simulations also reproduced most of the hydrogen bonds observed in the x-ray crystal structure. Furthermore, the obtained MD trajectories were used to estimate the binding free energy of the complex using the molecular mechanics/Poisson Boltzmann surface area (MM-PBSA) method. It was revealed by the inspection of the binding free energy components that the major contributions to the complex stability arose from electrostatic interactions.

  5. Structural analysis of β-prism lectin from Colocasia esculenta (L.) S chott.

    Science.gov (United States)

    Vajravijayan, S; Pletnev, S; Pletnev, V Z; Nandhagopal, N; Gunasekaran, K

    2016-10-01

    The Mannose-binding β-Prism Colocasia esculenta lectin (β-PCL) was purified from tubers using ion exchange chromatography. The purified β-PCL appeared as a single band of ∼12kDa on SDS-PAGE. β-PCL crystallizes in trigonal space group P3121 and diffracted to a resolution of 2.1Å. The structure was solved using Molecular replacement using Crocus vernus lectin (PDB: 3MEZ) as a model. From the final refined model to an R-factor of 16.5% and an Rfree of 20.4%, it has been observed that the biological unit consists of two β-Prism domains augmented through C-terminals swap over to form one of faces for each domain. Cα superposition of individual domains of β-PCL with individual domains of other related structures and superposition of whole protein structures were carried out. The higher RMS deviation for the superposition of whole structures suggest that β-prism domains assume different orientation in each structure.

  6. Eutirucallin, a RIP-2 type lectin from the latex of Euphorbia tirucalli L. presents proinflammatory properties.

    Directory of Open Access Journals (Sweden)

    Sanzio Silva Santana

    Full Text Available Lectins are carbohydrate-binding proteins that recognize and modulate physiological activities and have been used as a toll for detection and identification of biomolecules, and therapy of diseases. In this study we have isolated a lectin present in the latex of Euphorbia tirucalli, and named it Eutirucallin. The latex protein extract was subjected to ion exchange chromatography and showed two peaks with haemagglutinating activity. Polypeptides of 32 kDa protein extract strongly interacted with immobilized galactose (α-lactose > D-N-acetylgalactosamine. The Eutirucallin was obtained with a yield of 5.6% using the α-lactose column. The lectin domain has 32 kDa subunits and at least two of which are joined by disulfide bridges. The agglutinating capacity for human erythrocytes A(+, B(+ and O(+ is inhibited by D-galactose. The haemagglutinating activity of Eutirucallin was independent of Ca(2+ and maintained until the temperature of 55°C. Eutirucallin presented biological activities such as neutrophils recruitment and cytokine prodution by macrophages. The analysis of the trypsin-digested Eutirucallin by ms/ms in ESI-Q-TOFF resulted in nine peptides similar to type 2 ribosome-inactivating protein (type-2 RIP. It's partial sequence showed a similarity of 67.4 - 83.1% for the lectin domain of type-2 RIP [Ricin and Abrin (83.1%, Viscumin, Ebulin, Pulchellin, Cinnamomin, Volkensin and type-2 RIP Iris hollandica]. Our data suggest that Eutirucallin is a new member of type 2 ribosome-inactivating protein and presents biotechnological potential.

  7. Maize root lectins mediate the interaction with Herbaspirillum seropedicae via N-acetyl glucosamine residues of lipopolysaccharides.

    Science.gov (United States)

    Balsanelli, Eduardo; Tuleski, Thalita Regina; de Baura, Valter Antonio; Yates, Marshall Geoffrey; Chubatsu, Leda Satie; Pedrosa, Fabio de Oliveira; de Souza, Emanuel Maltempi; Monteiro, Rose Adele

    2013-01-01

    Herbaspirillum seropedicae is a plant growth-promoting diazotrophic betaproteobacterium which associates with important crops, such as maize, wheat, rice and sugar-cane. We have previously reported that intact lipopolysaccharide (LPS) is required for H. seropedicae attachment and endophytic colonization of maize roots. In this study, we present evidence that the LPS biosynthesis gene waaL (codes for the O-antigen ligase) is induced during rhizosphere colonization by H. seropedicae. Furthermore a waaL mutant strain lacking the O-antigen portion of the LPS is severely impaired in colonization. Since N-acetyl glucosamine inhibits H. seropedicae attachment to maize roots, lectin-like proteins from maize roots (MRLs) were isolated and mass spectrometry (MS) analysis showed that MRL-1 and MRL-2 correspond to maize proteins with a jacalin-like lectin domain, while MRL-3 contains a B-chain lectin domain. These proteins showed agglutination activity against wild type H. seropedicae, but failed to agglutinate the waaL mutant strain. The agglutination reaction was severely diminished in the presence of N-acetyl glucosamine. Moreover addition of the MRL proteins as competitors in H. seropedicae attachment assays decreased 80-fold the adhesion of the wild type to maize roots. The results suggest that N-acetyl glucosamine residues of the LPS O-antigen bind to maize root lectins, an essential step for efficient bacterial attachment and colonization.

  8. Maize root lectins mediate the interaction with Herbaspirillum seropedicae via N-acetyl glucosamine residues of lipopolysaccharides.

    Directory of Open Access Journals (Sweden)

    Eduardo Balsanelli

    Full Text Available Herbaspirillum seropedicae is a plant growth-promoting diazotrophic betaproteobacterium which associates with important crops, such as maize, wheat, rice and sugar-cane. We have previously reported that intact lipopolysaccharide (LPS is required for H. seropedicae attachment and endophytic colonization of maize roots. In this study, we present evidence that the LPS biosynthesis gene waaL (codes for the O-antigen ligase is induced during rhizosphere colonization by H. seropedicae. Furthermore a waaL mutant strain lacking the O-antigen portion of the LPS is severely impaired in colonization. Since N-acetyl glucosamine inhibits H. seropedicae attachment to maize roots, lectin-like proteins from maize roots (MRLs were isolated and mass spectrometry (MS analysis showed that MRL-1 and MRL-2 correspond to maize proteins with a jacalin-like lectin domain, while MRL-3 contains a B-chain lectin domain. These proteins showed agglutination activity against wild type H. seropedicae, but failed to agglutinate the waaL mutant strain. The agglutination reaction was severely diminished in the presence of N-acetyl glucosamine. Moreover addition of the MRL proteins as competitors in H. seropedicae attachment assays decreased 80-fold the adhesion of the wild type to maize roots. The results suggest that N-acetyl glucosamine residues of the LPS O-antigen bind to maize root lectins, an essential step for efficient bacterial attachment and colonization.

  9. Lectin cDNA and transgenic plants derived therefrom

    Science.gov (United States)

    Raikhel, Natasha V.

    1994-01-04

    Transgenic plants containing cDNA encoding Gramineae lectin are described. The plants preferably contain cDNA coding for barley lectin and store the lectin in the leaves. The transgenic plants, particularly the leaves exhibit insecticidal and fungicidal properties. GOVERNMENT RIGHTS This application was funded under Department of Energy Contract DE-AC02-76ER01338. The U.S. Government has certain rights under this application and any patent issuing thereon.

  10. Lectin histochemistry of the boar bulbourethral glands

    Directory of Open Access Journals (Sweden)

    E Badia

    2009-06-01

    Full Text Available The present study describes, for the first time, the glycosidic content of boar bulbourethral glands using lectin histochemistry. Fourteen horseradish peroxidase- or digoxigeninlabelled lectins with different carbohydrate specificities were used in samples obtained from 3 healthy Landrace boars. The results obtained indicate that endpiece and duct cells synthesize and secrete mainly O-glycoproteins with a- and b-D-N-acetylgalactosamine, b-D-galactose-b(1®3-D-Nacetylgalactosamine, D-N-acetylglucosamine and neuraminic acid residues. Glycoproteins secreted by bulbourethral glands have a role in the protection and lubrication of the urethra. In addition, they may be also involved in the regulation of the sperm metabolic activity and in the maintenance of the structural integrity of acrosomal and plasma membranes.

  11. C-type natriuretic peptide in prostate cancer

    DEFF Research Database (Denmark)

    Nielsen, Soeren Junge; Iversen, Peter; Rehfeld, Jens F.;

    2009-01-01

    C-type natriuretic peptide (CNP) is expressed in the male reproductive organs in pigs. To examine whether the human prostate also expresses the CNP gene, we measured CNP and N-terminal proCNP in prostate cancer tissue extracts and performed immunohistochemical biopsy staining. Additionally, pro......CNP-derived peptides were quantitated in plasma from patients with prostate cancer. Blood was collected from healthy controls and patients before surgery for localized prostate cancer. Tissue extracts were prepared from tissue biopsies obtained from radical prostatectomy surgery. N-terminal proCNP, proCNP (1......-50) and CNP were measured in plasma and tissue extracts. Biopsies were stained for CNP-22 and N-terminal proCNP. Tissue extracts from human prostate cancer contained mostly N-terminal proCNP [median 5.3 pmol/g tissue (range 1.0-12.9)] and less CNP [0.14 pmol/g tissue (0.01-1.34)]. Immunohistochemistry...

  12. Mathematical model of various statements of C-type Language

    Directory of Open Access Journals (Sweden)

    Manoj Kumar Srivastav

    2013-12-01

    Full Text Available Some of the important components of high level languages are statements, keywords, variable declarations, arrays, user defined functions etc. In case of object oriented programming language we use class, object, inheritance, operator overloading, function overloading, polymorphism etc. There are some common category of statements such as control statement, loop statements etc. Pointers are also one important concept in C-language. User defined functions, function subprograms or subroutines are also important concepts in different programming languages. The language like ALGOL was developed using Chomsky context free grammar. The similar concept used in C-type languages. The high level languages are now based on mathematical derivations and logic. Most of the components of any high level language can be obtained from simple mathematical logic and derivations. In the present study the authors have tried to give some unified mathematical model of few statements, arrays, user defined functions of C-language. However, the present method may further be extended to any other high level language.

  13. Are Vicilins Another Major Class of Legume Lectins?

    Directory of Open Access Journals (Sweden)

    Ana C. Ribeiro

    2014-12-01

    Full Text Available Legume lectins comprise a structurally related, Ca/Mn-dependent, widespread, abundant and well characterized lectin family when compared to the large number of lectins from other sources described in the literature. Strangely enough, no specific function has been assigned to them aside from a possible role in storage and/or defense. Using a recent and fine-tuned methodology capable of specific lectin identification, β-conglutin, Vicia faba vicilin and β-lathyrin, the vicilin storage globulins from Lupinus albus, V. faba and Lathyrus sativus, respectively, were shown to be capable of affinity binding to thoroughly washed erythrocyte membranes and of specific elution with appropriate sugars. Based on this evidence and on sparse data published in the literature, a second family of legume lectins is proposed: the 7S family of storage proteins from leguminous seeds, or family II of legume lectins. These lectins are also structurally related, widespread and well characterized. In addition, they self-aggregate in a Ca/Mg, electrostatic dependent manner and are even more abundant than the family I of legume lectins. Using the same evidence, reserve and defense roles may be attributed to family II of legume lectins.

  14. Algal Lectins as Potential HIV Microbicide Candidates

    Directory of Open Access Journals (Sweden)

    Dominique Schols

    2012-07-01

    Full Text Available The development and use of topical microbicides potentially offers an additional strategy to reduce the spread of the Human Immunodeficiency Virus (HIV. Carbohydrate-binding agents (CBAs that show specificity for high mannose carbohydrates on the surface of the heavily glycosylated envelope of HIV are endowed with potent anti-HIV activity. In fact, a number of algal lectins such as cyanovirin-N, microvirin, microcystis viridis lectin, scytovirin, Oscillatoria agardhii agglutinin and griffithsin are considered as potential microbicide candidates to prevent the sexual transmission of HIV through topical applications. They not only inhibit infection of cells by cell-free virus but they can also efficiently prevent virus transmission from virus-infected cells to uninfected CD4+ target T-lymphocytes and DC-SIGN-directed capture of HIV-1 and transmission to CD4+ T lymphocytes. This review focuses on the structural properties and carbohydrate specificity of these algal lectins, their antiviral activity against HIV and several other enveloped viruses, their safety profile and viral resistance patterns.

  15. Biosynthesis of the Snowdrop (Galanthus nivalis) Lectin in Ripening Ovaries.

    Science.gov (United States)

    Van Damme, E J; Peumans, W J

    1988-03-01

    The biosynthesis and processing of the Galanthus nivalis agglutinin were studied in vivo in ripening snowdrop ovaries. Using labeling and pulse chase labeling experiments it could be demonstrated that the snowdrop lectin is synthesized as a precursor of relative molecular weight (M(r)) 15,000 which is posttranslationally converted into the authentic lectin polypeptide of M(r) 13,000 with a half-life of about 6 hours. Gel filtration of an extract of [(3)H]leucine labeled ovaries on Sepharose 4B showed that a significant portion of the newly synthesized lectin is associated with the particulate fraction. When the organellar fraction was fractionated on isopycnic sucrose gradients this lectin banded in the same density region as the endoplasmic reticulum (ER) marker enzyme NADH cytochrome c reductase. Both radioactivity in lectin and in enzyme activity shifted towards a higher density in the presence of 2 millimolar Mg-acetate indicating that the labeled lectin was associated with the rough ER. Labeled lectin could be chased from the ER with a half-life of 4 hours and then accumulated in the soluble fraction. Whereas the ER-associated lectin contains exclusively polypeptides of M(r) 15,000 the soluble fraction contains both precursor molecules and mature lectin polypeptides. The snowdrop lectin in the ER is fully capable of binding immobilized mannose. It is associated into tetramers with an appropriate molecular weight of 60,000. These results indicate that newly synthesized snowdrop lectin is transiently associated with the ER before transport and processing.

  16. Identification of Novel O-Linked Glycosylated Toxoplasma Proteins by Vicia villosa Lectin Chromatography.

    Directory of Open Access Journals (Sweden)

    Kevin Wang

    Full Text Available Toxoplasma gondii maintains its intracellular life cycle using an extraordinary arsenal of parasite-specific organelles including the inner membrane complex (IMC, rhoptries, micronemes, and dense granules. While these unique compartments play critical roles in pathogenesis, many of their protein constituents have yet to be identified. We exploited the Vicia villosa lectin (VVL to identify new glycosylated proteins that are present in these organelles. Purification of VVL-binding proteins by lectin affinity chromatography yielded a number of novel proteins that were subjected to further study, resulting in the identification of proteins from the dense granules, micronemes, rhoptries and IMC. We then chose to focus on three proteins identified by this approach, the SAG1 repeat containing protein SRS44, the rhoptry neck protein RON11 as well as a novel IMC protein we named IMC25. To assess function, we disrupted their genes by homologous recombination or CRISPR/Cas9. The knockouts were all successful, demonstrating that these proteins are not essential for invasion or intracellular survival. We also show that IMC25 undergoes substantial proteolytic processing that separates the C-terminal domain from the predicted glycosylation site. Together, we have demonstrated that lectin affinity chromatography is an efficient method of identifying new glycosylated parasite-specific proteins.

  17. Identification of Novel O-Linked Glycosylated Toxoplasma Proteins by Vicia villosa Lectin Chromatography.

    Science.gov (United States)

    Wang, Kevin; Peng, Eric D; Huang, Amy S; Xia, Dong; Vermont, Sarah J; Lentini, Gaelle; Lebrun, Maryse; Wastling, Jonathan M; Bradley, Peter J

    2016-01-01

    Toxoplasma gondii maintains its intracellular life cycle using an extraordinary arsenal of parasite-specific organelles including the inner membrane complex (IMC), rhoptries, micronemes, and dense granules. While these unique compartments play critical roles in pathogenesis, many of their protein constituents have yet to be identified. We exploited the Vicia villosa lectin (VVL) to identify new glycosylated proteins that are present in these organelles. Purification of VVL-binding proteins by lectin affinity chromatography yielded a number of novel proteins that were subjected to further study, resulting in the identification of proteins from the dense granules, micronemes, rhoptries and IMC. We then chose to focus on three proteins identified by this approach, the SAG1 repeat containing protein SRS44, the rhoptry neck protein RON11 as well as a novel IMC protein we named IMC25. To assess function, we disrupted their genes by homologous recombination or CRISPR/Cas9. The knockouts were all successful, demonstrating that these proteins are not essential for invasion or intracellular survival. We also show that IMC25 undergoes substantial proteolytic processing that separates the C-terminal domain from the predicted glycosylation site. Together, we have demonstrated that lectin affinity chromatography is an efficient method of identifying new glycosylated parasite-specific proteins.

  18. In vivo and in vitro antibacterial activity of conglutinin, a mammalian plasma lectin

    DEFF Research Database (Denmark)

    Friis-Christiansen, P; Thiel, S; Svehag, S E;

    1990-01-01

    of BALB/c mice with Salmonella typhimurium is mediated by conglutinin. Conglutinin also demonstrated antibacterial activity against E. coli and S. typhimurium in vitro. The expression of this activity required the presence of heat-labile serum factors and peritoneal exudate or spleen cells......, but not antibodies to the bacteria. Antibacterial activity was also demonstrated when the bacteria were pretreated with serum at 37 degrees C before incubation with conglutinin and cells. The activity of conglutinin was not observed when factor I-deficient or EDTA-treated serum was used instead of normal serum......Conglutinin is a mammalian C-type lectin which agglutinates iC3b-coated erythrocytes. Ingram [13] found that euglobulin from bovine serum may confer partial protection against experimental infections in mice. We now present evidence that the protective activity in euglobulin against infections...

  19. Mannose-binding lectin in pre-menopausal women with recurrent urinary tract infections.

    Science.gov (United States)

    Colodner, R; Nitzan, O; Chazan, B; Edelstein, H; Raz, R

    2010-09-01

    Mannose-binding lectin (MBL) comprises an oligomeric serum protein that is a member of the collectin class of the C-type lectin superfamily. Its deficiency is genetically determined and confers predisposition to recurrent infections as well as increased infection severity. This correlation has been demonstrated in recurrent furunculosis caused by Staphylococcus aureus, and in pneumococcal and Candida infections. The present study aimed to determine whether there is a correlation between MBL serum levels and recurrent urinary tact infections (UTI) in pre-menopausal women. The present aged-matched double-blind controlled study was conducted in 100 pre-menopausal adult women: 50 who suffered from recurrent UTI and 50 without UTI. The MBL concentration was measured in a single serum sample from each patient using an enzyme-linked immunosorbent assay. MBL serum levels [median (range)] were 2500 (4-12,000) ng/mL and 2105 (4-22,800) ng/mL for the research and control groups, respectively. The results from the two groups were compared and were not statistically different (p 0.4). According to these results, MBL serum levels are not associated with an increased risk for recurrent UTI in pre-menopausal women.

  20. Pancreatitis-associated protein: From a lectin to an anti-inflammatory cytokine

    Institute of Scientific and Technical Information of China (English)

    Daniel Closa; Yoshiharu Motoo; Juan L Iovanna

    2007-01-01

    Pancreatitis-associated protein (PAP) was discovered in the pancreatic juice of rats with acute pancreatitis. PAP is a 16 kDa secretory protein structurally related to the C-type lectins although classical lectin-related function has not been reported yet. Then, it was demonstrated that PAP expression may be activated in some tissues in a constitutive or injury- and inflammation-induced manner. More recently, it has been found that PAP acts as an anti-inflammatory factor in vitro and in vivo.PAP expression can be induced by several pro- and anti-inflammatory cytokines and by itself through a JAK/STAT3-dependent pathway. PAP is able to activate the expression of the anti-inflammatory factor SOCS3 through the JAK/STAT3-dependent pathway. The JAK/STAT3/SOCS3 pathway seems to be a common point between PAP and several cytokines. Therefore,it is reasonable to propose that PAP is a new antiinflammatory cytokine.

  1. Mannose-binding lectin genetics: from A to Z

    DEFF Research Database (Denmark)

    Garred, Peter

    2008-01-01

    MBL (mannose-binding lectin) is primarily a liver-derived collagen-like serum protein. It binds sugar structures on micro-organisms and on dying host cells and is one of the four known mediators that initiate activation of the complement system via the lectin pathway. Common variant alleles...

  2. Interaction of native and asialo rat sublingual glycoproteins with lectins.

    Science.gov (United States)

    Wu, A M; Herp, A; Song, S C; Wu, J H; Chang, K S

    1995-01-01

    The binding properties of the rat sublingual glycoprotein (RSL) and its asialo product with lectins were characterized by quantitative precipitin(QPA) and precipitin inhibition(QPIA) assays. Among twenty lectins tested for QPA, native RSL reacted well only with Artocarpus integrifolia (jacalin), but weakly or not at all with the other lectins. However, its asialo product (asialo-RSL) reacted strongly with many Gal and GalNAc specific lectins-it bound best to three of the GalNAc alpha 1-->Ser/Thr (Tn) and/or Gal beta 1-->4GlcNAc (II) active lectins [jacalin, Wistaria floribunda and Ricinus communis agglutinins] and completely precipitated each of these three lectins. Asialo-RSL also reacted well with Abrus precatorius, Glycine max, Bauhinia purpurea alba, and Maclura pomifera agglutinins, and abrin-a, but not with Arachis hypogeae and Dolichos biflorus agglutinins. The interaction between asialo-RSL and lectins were inhibited by either Gal beta 1-->4GlcNAc, p-NO2-phenyl alpha-GalNAc or both. The mapping of the precipitation and inhibition profiles leads to the conclusion that the asialo rat sublingual glycoprotein provides important ligands for II (Gal beta 1-->4GlcNAc beta 1-->) and Tn (GalNAc alpha 1-->Ser/Thr) active lectins.

  3. Combined biochemical and cytological analysis of membrane trafficking using lectins.

    Science.gov (United States)

    Morgan, Gareth W; Kail, Mark; Hollinshead, Michael; Vaux, David J

    2013-10-01

    We have tested the application of high-mannose-binding lectins as analytical reagents to identify N-glycans in the early secretory pathway of HeLa cells during subcellular fractionation and cytochemistry. Post-endoplasmic reticulum (ER) pre-Golgi intermediates were separated from the ER on Nycodenz-sucrose gradients, and the glycan composition of each gradient fraction was profiled using lectin blotting. The fractions containing the post-ER pre-Golgi intermediates are found to contain a subset of N-linked α-mannose glycans that bind the lectins Galanthus nivalis agglutinin (GNA), Pisum sativum agglutinin (PSA), and Lens culinaris agglutinin (LCA) but not lectins binding Golgi-modified glycans. Cytochemical analysis demonstrates that high-mannose-containing glycoproteins are predominantly localized to the ER and the early secretory pathway. Indirect immunofluorescence microscopy revealed that GNA colocalizes with the ER marker protein disulfide isomerase (PDI) and the COPI coat protein β-COP. In situ competition with concanavalin A (ConA), another high-mannose specific lectin, and subsequent GNA lectin histochemistry refined the localization of N-glyans containing nonreducing mannosyl groups, accentuating the GNA vesicular staining. Using GNA and treatments that perturb ER-Golgi transport, we demonstrate that lectins can be used to detect changes in membrane trafficking pathways histochemically. Overall, we find that conjugated plant lectins are effective tools for combinatory biochemical and cytological analysis of membrane trafficking of glycoproteins.

  4. Lessons learned from mice deficient in lectin complement pathway molecules

    DEFF Research Database (Denmark)

    Genster, Ninette Benthien; Takahashi, Minoru; Sekine, Hideharu;

    2014-01-01

    The lectin pathway of the complement system is initiated when the pattern-recognition molecules, mannose-binding lectin (MBL), ficolins or collectin-11, bind to invading pathogens or damaged host cells. This leads to activation of MBL/ficolin/collectin-11 associated serine proteases (MASPs), which...... in turn activate downstream complement components, ultimately leading to elimination of the pathogen. Mice deficient in the key molecules of lectin pathway of complement have been generated in order to build knowledge of the molecular mechanisms of the lectin pathway in health and disease. Despite...... in complement activation, pathogen infection, coagulation, host tissue injury and developmental biology have been revealed by in vivo investigations. This review provides an overview of the mice deficient in lectin pathway molecules and highlights some of the most important findings that have resulted from...

  5. Lectin activity in mycelial extracts of Fusarium species.

    Science.gov (United States)

    Bhari, Ranjeeta; Kaur, Bhawanpreet; Singh, Ram S

    2016-01-01

    Lectins are non-immunogenic carbohydrate-recognizing proteins that bind to glycoproteins, glycolipids, or polysaccharides with high affinity and exhibit remarkable ability to agglutinate erythrocytes and other cells. In the present study, ten Fusarium species previously not explored for lectins were screened for the presence of lectin activity. Mycelial extracts of F. fujikuroi, F. beomiformii, F. begoniae, F. nisikadoi, F. anthophilum, F. incarnatum, and F. tabacinum manifested agglutination of rabbit erythrocytes. Neuraminidase treatment of rabbit erythrocytes increased lectin titers of F. nisikadoi and F. tabacinum extracts, whereas the protease treatment resulted in a significant decline in agglutination by most of the lectins. Results of hapten inhibition studies demonstrated unique carbohydrate specificity of Fusarium lectins toward O-acetyl sialic acids. Activity of the majority of Fusarium lectins exhibited binding affinity to d-ribose, l-fucose, d-glucose, l-arabinose, d-mannitol, d-galactosamine hydrochloride, d-galacturonic acid, N-acetyl-d-galactosamine, N-acetyl-neuraminic acid, 2-deoxy-d-ribose, fetuin, asialofetuin, and bovine submaxillary mucin. Melibiose and N-glycolyl neuraminic acid did not inhibit the activity of any of the Fusarium lectins. Mycelial extracts of F. begoniae, F. nisikadoi, F. anthophilum, and F. incarnatum interacted with most of the carbohydrates tested. F. fujikuroi and F. anthophilum extracts displayed strong interaction with starch. The expression of lectin activity as a function of culture age was investigated. Most species displayed lectin activity on the 7th day of cultivation, and it varied with progressing of culture age.

  6. Lectin activity in mycelial extracts of Fusarium species

    Directory of Open Access Journals (Sweden)

    Ranjeeta Bhari

    Full Text Available ABSTRACT Lectins are non-immunogenic carbohydrate-recognizing proteins that bind to glycoproteins, glycolipids, or polysaccharides with high affinity and exhibit remarkable ability to agglutinate erythrocytes and other cells. In the present study, ten Fusarium species previously not explored for lectins were screened for the presence of lectin activity. Mycelial extracts of F. fujikuroi, F. beomiformii, F. begoniae, F. nisikadoi, F. anthophilum, F. incarnatum, and F. tabacinum manifested agglutination of rabbit erythrocytes. Neuraminidase treatment of rabbit erythrocytes increased lectin titers of F. nisikadoi and F. tabacinum extracts, whereas the protease treatment resulted in a significant decline in agglutination by most of the lectins. Results of hapten inhibition studies demonstrated unique carbohydrate specificity of Fusarium lectins toward O-acetyl sialic acids. Activity of the majority of Fusarium lectins exhibited binding affinity to D-ribose, L-fucose, D-glucose, L-arabinose, D-mannitol, D-galactosamine hydrochloride, D-galacturonic acid, N-acetyl-d-galactosamine, N-acetyl-neuraminic acid, 2-deoxy-D-ribose, fetuin, asialofetuin, and bovine submaxillary mucin. Melibiose and N-glycolyl neuraminic acid did not inhibit the activity of any of the Fusarium lectins. Mycelial extracts of F. begoniae, F. nisikadoi, F. anthophilum, and F. incarnatum interacted with most of the carbohydrates tested. F. fujikuroi and F. anthophilum extracts displayed strong interaction with starch. The expression of lectin activity as a function of culture age was investigated. Most species displayed lectin activity on the 7th day of cultivation, and it varied with progressing of culture age.

  7. Lectin binding to cystic stages of Taenia taeniaeformis.

    Science.gov (United States)

    Sandeman, R M; Williams, J F

    1984-10-01

    Studies of membrane glycoconjugates of Taenia taeniaeformis were initiated by assays of the lectin binding characteristics of 35-day-old cysticerci. Parasites fixed in glutaraldehyde were incubated with one of the following FITC-labelled lectins: Concanavalin A (Con A), Lens culinaris agglutinin (LCA), Ricinus communis agglutinin (RCA), peanut agglutinin (PNA), fucose binding protein (FBP) and wheat germ agglutinin (WGA) and either their specific or a nonspecific sugar. Ultraviolet microscopy revealed that only Con A and LCA bound in large amounts to the surface of cysticerci. This binding was partly inhibited by the specific sugar, but the nonspecific sugar had little effect. The lectin not removed by either of the sugars may have been bound nonspecifically to the charged glycocalyx. Lectins were primarily bound on the anterior third of the parasite around the scolex invagination. Kinetic studies of lectin interactions were carried out with LCA and RCA by spectrophotofluorometric analysis of the amount bound specifically or nonspecifically over a range of lectin concentrations. Lens culinaris lectin binding was found to be specific and involve 2 receptors which showed large differences in their affinity for lectin and prevalence on the surface. Ricinus communis lectin did not bind specifically but nonspecific interactions were observed. Adherence of small numbers of host cells was shown to have no measurable effect on the lectin binding characteristics. The results suggest that the major surface carbohydrates exposed are D-mannose and/or D-glucose residues with the other sugar groups poorly represented. This relatively homogeneous surface may have implications for the antigenicity of the parasite in its host.

  8. Molecular characterization of a saline-soluble lectin from a parasitic fungus: Extensive sequence similarities between fungal lectins

    NARCIS (Netherlands)

    Rosén, S.; Kata, M.; Persson, Y.; Lipniunas, P.H.; Wikström, M.; Hondel, C.A.M.J.J. van den; Brink, J.M. van den; Rask, L.; Hedén, L.O.; Tunlid, A.

    1996-01-01

    It has been proposed that the interactions between several parasite and pathogenic fungi and their hosts are mediated by soluble lectins present in the fungus. We have cloned and analyzed a gene encoding such a lectin (AOL) from the nematophagous fungus Arthrobotrys oligospora (deuteromycete). The d

  9. Genetic influences on Mannan-binding lectin (MBL) and Mannan-binding lectin associated serine protease-2 (MASP-2) activity

    DEFF Research Database (Denmark)

    Sorensen, Grith L; Petersen, Inge; Thiel, Steffen;

    2007-01-01

    The lectin pathway of the complement system is activated when Mannan-binding lectin (MBL) in complex with MASP-2 binds microorganisms. Polymorphisms in both genes are responsible for low serum levels, which associate with increased risk of infection and autoimmune disease. The present study inclu...

  10. Heterocomplexes of mannose-binding lectin and the pentraxins PTX3 or SAP trigger cross-activation of the complement system

    DEFF Research Database (Denmark)

    Ma, Ying Jie; Doni, Andrea; Skjødt, Mikkel-Ole;

    2011-01-01

    The long pentraxin 3 (PTX3), serum amyloid P component (SAP) and C-reactive protein (CRP) belong to the pentraxin family of pattern recognition molecules involved in tissue homeostasis and innate immunity. They interact with C1q from the classical complement pathway. Whether this also occurs via...... the analogous mannose-binding lectin (MBL) from the lectin complement pathway is unknown. Thus, we investigated the possible interaction between MBL and the pentraxins. We report that MBL bound PTX3 and SAP partly via its collagen-like domain, but not CRP. MBL:PTX3 complex formation resulted in recruitment of C......1q, but this was not seen for the MBL:SAP complex. However, both MBL:PTX3 and MBL:SAP complexes enhanced C4 and C3 deposition and opsonophagocytosis of Candida albicans by polymorphonuclear leukocytes. Interaction between MBL and PTX3 lead to communication between the lectin and classical complement...

  11. Noncovalent PEGylation via Lectin-Glycopolymer Interactions.

    Science.gov (United States)

    Antonik, Paweł M; Eissa, Ahmed M; Round, Adam R; Cameron, Neil R; Crowley, Peter B

    2016-08-08

    PEGylation, the covalent modification of proteins with polyethylene glycol, is an abundantly used technique to improve the pharmacokinetics of therapeutic proteins. The drawback with this methodology is that the covalently attached PEG can impede the biological activity (e.g., reduced receptor-binding capacity). Protein therapeutics with "disposable" PEG modifiers have potential advantages over the current technology. Here, we show that a protein-polymer "Medusa complex" is formed by the combination of a hexavalent lectin with a glycopolymer. Using NMR spectroscopy, small-angle X-ray scattering (SAXS), size exclusion chromatography, and native gel electrophoresis it was demonstrated that the fucose-binding lectin RSL and a fucose-capped polyethylene glycol (Fuc-PEG) form a multimeric assembly. All of the experimental methods provided evidence of noncovalent PEGylation with a concomitant increase in molecular mass and hydrodynamic radius. The affinity of the protein-polymer complex was determined by ITC and competition experiments to be in the micromolar range, suggesting that such systems have potential biomedical applications.

  12. The concentration of the C-type lectin, mannan-binding protein, in human plasma increases during an acute phase response

    DEFF Research Database (Denmark)

    Thiel, S; Holmskov, U; Hviid, L

    1992-01-01

    Two ELISAs for estimating mannan-binding protein (MBP) were constructed and the concentration of MBP in plasma was followed in patients undergoing major surgery and in patients having a malarial attack. In both cases increases of MBP in the plasma were observed. The relative increase and the kine......Two ELISAs for estimating mannan-binding protein (MBP) were constructed and the concentration of MBP in plasma was followed in patients undergoing major surgery and in patients having a malarial attack. In both cases increases of MBP in the plasma were observed. The relative increase...... and the kinetics varied from person to person. The concentration of MBP increased between 1.5- and three-fold following surgery. In some patients an increase was seen at day 1 whereas in others the increase was not observed until days 3-9. In the malaria patients an increased level of MBP was maintained during 30...

  13. New sensitive detection method for lectin hemagglutination using microscopy.

    Science.gov (United States)

    Adamová, Lenka; Malinovská, Lenka; Wimmerová, Michaela

    2014-10-01

    The blood group system AB0 is determined by the composition of terminal oligosaccharides on red blood cells. Thanks to this structural feature, these groups can be recognized by saccharide-recognizing compounds. Lectins are proteins that are able to reversibly bind saccharide structures. They generally occur as multimers and are known as hemagglutination agents. Hemagglutination is a process in which blood cells are cross-linked via multivalent molecules. Apart from lectins, hemagglutination can also be caused by antibodies or viruses. A hemagglutination assay is commonly used for the detection of multivalent molecules that recognize blood cells, in order to search for their sugar specificity. It is traditionally performed on a microtiter plate, where the lectin solution is serially diluted and the lowest concentration of lectin causing agglutination is detected. This experimental set-up is utilized further for testing lectin specificity via a hemagglutination inhibition assay. We have developed a new way of detecting hemagglutination using microscopy, which was tested on purified lectins as well as cell lysates. Hemagglutination was performed on a microscope slide directly and detected using a microscope. Comparison with the standard hemagglutination assay using microtiter plates revealed that microscopic approach is faster and more robust and allows fast determination of lectin activities immediately in bacterial cytosols.

  14. Strict specificity for high-mannose type N-glycans and primary structure of a red alga Eucheuma serra lectin.

    Science.gov (United States)

    Hori, Kanji; Sato, Yuichiro; Ito, Kaori; Fujiwara, Yoshifumi; Iwamoto, Yasumasa; Makino, Hiroyuki; Kawakubo, Akihiro

    2007-05-01

    We have elucidated the carbohydrate-binding profile of a non-monosaccharide-binding lectin named Eucheuma serra lectin (ESA)-2 from the red alga Eucheuma serra using a lectin-immobilized column and a centrifugal ultrafiltration-high performance liquid chromatography method with a variety of fluorescence-labeled oligosaccharides. In both methods, ESA-2 exclusively bound with high-mannose type (HM) N-glycans, but not with any of other N-glycans including complex type, hybrid type and core pentasaccharides, and oligosaccharides from glycolipids. These findings indicate that ESA-2 recognizes the branched oligomannosides of the N-glycans. However, ESA-2 did not bind with any of the free oligomannoses examined that are constituents of the branched oligomannosides implying that the portion of the core N-acetyl-D-glucosamine (GlcNAc) residue(s) of the N-glycans is also essential for binding. Thus, the algal lectin was strictly specific for HM N-glycans and recognized the extended carbohydrate structure with a minimum size of the pentasaccharide, Man(alpha1-3)Man(alpha1-6)Man(beta1-4)GlcNAc(beta1-4) GlcNAc. Kinetic analysis of binding with a HM heptasaccharide (M5) showed that ESA-2 has four carbohydrate-binding sites per polypeptide with a high association constant of 1.6x10(8) M-1. Sequence analysis, by a combination of Edman degradation and mass analyses of the intact protein and of peptides produced by its enzymic digestions, showed that ESA-2 is composed of 268 amino acids (molecular weight 27950) with four tandemly repeated domains of 67 amino acids. The number of repeats coincided with the number of carbohydrate-binding sites in the monomeric molecule. Surprisingly, the marine algal lectin was homologous to hemagglutinin from the soil bacterium Myxococcus xanthus.

  15. Identification and characterization of a novel legume-like lectin cDNA sequence from the red marine algae Gracilaria fisheri

    Indian Academy of Sciences (India)

    Sukanya Suttisrisung; Saengchan Senapin; Boonsirm Withyachumnarnkul; Kanokpan Wongprasert

    2011-12-01

    A legume-type lectin (L-lectin) gene of the red algae Gracilaria fisheri (GFL) was cloned by rapid amplification of cDNA ends (RACE). The full-length cDNA of GFL was 1714 bp and contained a 1542 bp open reading frame encoding 513 amino acids with a predicted molecular mass of 56.5 kDa. Analysis of the putative amino acid sequence with NCBI-BLAST revealed a high homology (30–68%) with legume-type lectins (L-lectin) from Griffithsia japonica, Clavispora lusitaniae, Acyrthosiphon pisum, Tetraodon nigroviridis and Xenopus tropicalis. Phylogenetic relationship analysis showed the highest sequence identity to a glycoprotein of the red algae Griffithsia japonica (68%) (GenBank number AAM93989). Conserved Domain Database analysis detected an N-terminal carbohydrate recognition domain (CRD), the characteristic of L-lectins, which contained two sugar binding sites and a metal binding site. The secondary structure prediction of GFL showed a -sheet structure, connected with turn and coil. The most abundant structural element of GFL was the random coil, while the -helixes were distributed at the N- and C-termini, and 21 -sheets were distributed in the CRD. Computer analysis of three-dimensional structure showed a common feature of L-lectins of GFL, which included an overall globular shape that was composed of a -sandwich of two anti-parallel -sheets, monosaccharide binding sites, were on the top of the structure and in proximity with a metal binding site. Northern blot analysis using a DIG-labelled probe derived from a partial GFL sequence revealed a hybridization signal of ∼1.7 kb consistent with the length of the full-length GFL cDNA identified by RACE. No detectable band was observed from control total RNA extracted from filamentous green algae.

  16. Identification and characterization of a novel legume-like lectin cDNA sequence from the red marine algae Gracilaria fisheri.

    Science.gov (United States)

    Suttisrisung, Sukanya; Senapin, Saengchan; Withyachumnarnkul, Boonsirm; Wongprasert, Kanokpan

    2011-12-01

    A legume-type lectin (L-Lectin) gene of the red algae Gracilaria fisheri (GFL) was cloned by rapid amplification of cDNA ends (RACE). The full-length cDNA of GFL was 1714 bp and contained a 1542 bp open reading frame encoding 513 amino acids with a predicted molecular mass of 56.5 kDa. Analysis of the putative amino acid sequence with NCBI-BLAST revealed a high homology (30-68%) with legume-type lectins (L-lectin) from Griffithsia japonica, Clavispora lusitaniae, Acyrthosiphon pisum, Tetraodon nigroviridis and Xenopus tropicalis. Phylogenetic relationship analysis showed the highest sequence identity to a glycoprotein of the red algae Griffithsia japonica (68%) (GenBank number AAM93989). Conserved Domain Database analysis detected an N-terminal carbohydrate recognition domain (CRD), the characteristic of L-lectins, which contained two sugar binding sites and a metal binding site. The secondary structure prediction of GFL showed a beta-sheet structure, connected with turn and coil. The most abundant structural element of GFL was the random coil, while the alpha-helixes were distributed at the N- and C-termini, and 21 beta-sheets were distributed in the CRD. Computer analysis of three-dimensional structure showed a common feature of L-lectins of GFL, which included an overall globular shape that was composed of a beta-sandwich of two anti-parallel beta-sheets, monosaccharide binding sites, were on the top of the structure and in proximity with a metal binding site. Northern blot analysis using a DIG-labelled probe derived from a partial GFL sequence revealed a hybridization signal of (approx.) 1.7 kb consistent with the length of the full-length GFL cDNA identified by RACE. No detectable band was observed from control total RNA extracted from filamentous green algae.

  17. Self-assembled carbohydrate-based vesicles for lectin targeting.

    Science.gov (United States)

    Dos Santos, Marinalva Cardoso; Micheletto, Yasmine Miguel Serafini; da Silveira, Nadya Pesce; da Silva Pinto, Luciano; Giacomelli, Fernando Carlos; de Lima, Vânia Rodrigues; Frizon, Tiago Elias Allievi; Dal-Bó, Alexandre Gonçalves

    2016-12-01

    This study examined the physicochemical interactions between vesicles formed by phosphatidylcholine (PC) and glycosylated polymeric amphiphile N-acetyl-β-d-glucosaminyl-PEG900-docosanate (C22PEG900GlcNAc) conjugated with Bauhinia variegata lectin (BVL). Lectins are proteins or glycoproteins capable of binding glycosylated membrane components. Accordingly, the surface functionalization by such entities is considered a potential strategy for targeted drug delivery. We observed increased hydrodynamic radii (RH) of PC+C22PEG900GlcNAc vesicles in the presence of lectins, suggesting that this aggregation was due to the interaction between lectins and the vesicular glycosylated surfaces. Furthermore, changes in the zeta potential of the vesicles with increasing lectin concentrations implied that the vesicular glycosylated surfaces were recognized by the investigated lectin. The presence of carbohydrate residues on vesicle surfaces and the ability of the vesicles to establish specific interactions with BVL were further explored using atomic force microscopy (AFM) and small-angle X-ray scattering (SAXS) analysis. The results indicated that the thickness of the hydrophilic layer was to some extent influenced by the presence of lectins. The presence of lectins required a higher degree of polydispersity as indicated by the width parameter of the log-normal distribution of size, which also suggested more irregular structures. Reflectance Fourier transform infrared (HATR-FTIR), differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-vis.) analyses revealed that the studied lectin preferentially interacted with the choline and carbonyl groups of the lipid, thereby changing the choline orientation and intermolecular interactions. The protein also discretely reduced the intermolecular communication of the hydrophobic acyl chains, resulting in a disordered state.

  18. Fine specificities of two lectins from Cymbosema roseum seeds: a lectin specific for high-mannose oligosaccharides and a lectin specific for blood group H type II trisaccharide.

    Science.gov (United States)

    Dam, Tarun K; Cavada, Benildo S; Nagano, Celso S; Rocha, Bruno Am; Benevides, Raquel G; Nascimento, Kyria S; de Sousa, Luiz Ag; Oscarson, Stefan; Brewer, C Fred

    2011-07-01

    The legume species of Cymbosema roseum of Diocleinae subtribe produce at least two different seed lectins. The present study demonstrates that C. roseum lectin I (CRL I) binds with high affinity to the "core" trimannoside of N-linked oligosaccharides. Cymbosema roseum lectin II (CRL II), on the other hand, binds with high affinity to the blood group H trisaccharide (Fucα1,2Galα1-4GlcNAc-). Thermodynamic and hemagglutination inhibition studies reveal the fine binding specificities of the two lectins. Data obtained with a complete set of monodeoxy analogs of the core trimannoside indicate that CRL I recognizes the 3-, 4- and 6-hydroxyl groups of the α(1,6) Man residue, the 3- and 4-hydroxyl group of the α(1,3) Man residue and the 2- and 4-hydroxyl groups of the central Man residue of the trimannoside. CRL I possesses enhanced affinities for the Man5 oligomannose glycan and a biantennary complex glycan as well as glycoproteins containing high-mannose glycans. On the other hand, CRL II distinguishes the blood group H type II epitope from the Lewis(x), Lewis(y), Lewis(a) and Lewis(b) epitopes. CRL II also distinguishes between blood group H type II and type I trisaccharides. CRL I and CRL II, respectively, possess differences in fine specificities when compared with other reported mannose and fucose recognizing lectins. This is the first report of a mannose-specific lectin (CRL I) and a blood group H type II-specific lectin (CRL II) from seeds of a member of the Diocleinae subtribe.

  19. Lectin-like bacteriocins from Pseudomonas spp. utilise D-rhamnose containing lipopolysaccharide as a cellular receptor.

    Directory of Open Access Journals (Sweden)

    Laura C McCaughey

    2014-02-01

    Full Text Available Lectin-like bacteriocins consist of tandem monocot mannose-binding domains and display a genus-specific killing activity. Here we show that pyocin L1, a novel member of this family from Pseudomonas aeruginosa, targets susceptible strains of this species through recognition of the common polysaccharide antigen (CPA of P. aeruginosa lipopolysaccharide that is predominantly a homopolymer of D-rhamnose. Structural and biophysical analyses show that recognition of CPA occurs through the C-terminal carbohydrate-binding domain of pyocin L1 and that this interaction is a prerequisite for bactericidal activity. Further to this, we show that the previously described lectin-like bacteriocin putidacin L1 shows a similar carbohydrate-binding specificity, indicating that oligosaccharides containing D-rhamnose and not D-mannose, as was previously thought, are the physiologically relevant ligands for this group of bacteriocins. The widespread inclusion of d-rhamnose in the lipopolysaccharide of members of the genus Pseudomonas explains the unusual genus-specific activity of the lectin-like bacteriocins.

  20. Lectin-like bacteriocins from Pseudomonas spp. utilise D-rhamnose containing lipopolysaccharide as a cellular receptor.

    Science.gov (United States)

    McCaughey, Laura C; Grinter, Rhys; Josts, Inokentijs; Roszak, Aleksander W; Waløen, Kai I; Cogdell, Richard J; Milner, Joel; Evans, Tom; Kelly, Sharon; Tucker, Nicholas P; Byron, Olwyn; Smith, Brian; Walker, Daniel

    2014-02-01

    Lectin-like bacteriocins consist of tandem monocot mannose-binding domains and display a genus-specific killing activity. Here we show that pyocin L1, a novel member of this family from Pseudomonas aeruginosa, targets susceptible strains of this species through recognition of the common polysaccharide antigen (CPA) of P. aeruginosa lipopolysaccharide that is predominantly a homopolymer of D-rhamnose. Structural and biophysical analyses show that recognition of CPA occurs through the C-terminal carbohydrate-binding domain of pyocin L1 and that this interaction is a prerequisite for bactericidal activity. Further to this, we show that the previously described lectin-like bacteriocin putidacin L1 shows a similar carbohydrate-binding specificity, indicating that oligosaccharides containing D-rhamnose and not D-mannose, as was previously thought, are the physiologically relevant ligands for this group of bacteriocins. The widespread inclusion of d-rhamnose in the lipopolysaccharide of members of the genus Pseudomonas explains the unusual genus-specific activity of the lectin-like bacteriocins.

  1. The Lectin Pathway of Complement and Biocompatibility

    DEFF Research Database (Denmark)

    Hein, Estrid; Garred, Peter

    2015-01-01

    In modern health technologies the use of biomaterials in the form of stents, haemodialysis tubes, artificial implants, bypass circuits etc. is rapidly expanding. The exposure of synthetic, foreign surfaces to the blood and tissue of the host, calls for strict biocompatibility in respect to contac...... been broadly documented. However, the specific role of lectin pathway and the pattern recognition molecules initiating the pathway has only been transiently investigated. Here we review the current data on the field....... and the alternative pathway, all converging in an amplification loop of the cascade system and downstream reactions. Thus, when exposed to foreign substances complement components will be activated and lead to a powerful inflammatory response. Biosurface induced complement activation is a recognised issue that has...

  2. Detection of Lectins by Saccharide-gold Nanoparticle Conjugates

    Institute of Scientific and Technical Information of China (English)

    HOU Qiong; WANG Jin-e; LIU Xia; LI Xiao-kun; MA Li-na; DUAN Wu-biao; WANG Zhen-xin

    2012-01-01

    A general functionalization strategy was reported,which enables one to conjugate saccharide(SA) on gold nanoparticle(GNP) surface without affecting SA properties.First,disulfide phenylboronic acid(Bor) functionalized GNPs(Bor@GNPs) were synthesized by the reaction of citrate stabilized GNPs of 13 nm in diameter with the mixture of Bor and pentapeptide(Cys-Ala-Leu-Asn-Asn,CALNN).Subsequently,the SA-GNP conjugates(SA@GNPs) were prepared by coupling SA to the GNP surface via the reaction of phenylboronic acid(PBA) with the cis-diol configuration in SA.The interactions of three SA@GNPs with three lectins have been analyzed by UV-visible spectroscopic and transmission electronic microscopic(TEM) techniques,respectively.The experimental results demonstrate that SA@GNPs can efficiently bind to lectins and show a great promise as optical probes for monitoring specific affinities of lectins for SA,and detecting lectins with high sensitivity.

  3. Isolation and characterization of a lectin from Annona muricata seeds.

    Science.gov (United States)

    Damico, D C S; Freire, M G M; Gomes, V M; Toyama, M H; Marangoni, S; Novello, J C; Macedo, M L R

    2003-11-01

    A lectin with a high affinity for glucose/mannose was isolated from Annona muricata seeds (Annonaceae) by gel filtration chromatography on Sephacryl S-200, ion exchange chromatography on a DEAE SP-5 PW column, and molecular exclusion on a Protein Pak Glass 300 SW column. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (PAGE) yielded two protein bands of approximately 14 kDa and 22 kDa. However, only one band was seen in native PAGE. The Mr of the lectin estimated by fast-performance liquid chromatography-gel filtration on Superdex 75 was 22 kDa. The lectin was a glycoprotein with 8% carbohydrate (neutral sugar) and required divalent metal cations (Ca2+, Mg2+, and Mn2+) for full activity. Amino acid analysis revealed a large content of Glx, Gly, Phe, and Lys. The lectin agglutinated dog, chicken, horse, goose, and human erythrocytes and inhibited the growth of the fungi Fusarium oxysporum, Fusarium solani, and Colletotrichum musae.

  4. Insights into Animal and Plant Lectins with Antimicrobial Activities

    Directory of Open Access Journals (Sweden)

    Renata de Oliveira Dias

    2015-01-01

    Full Text Available Lectins are multivalent proteins with the ability to recognize and bind diverse carbohydrate structures. The glyco -binding and diverse molecular structures observed in these protein classes make them a large and heterogeneous group with a wide range of biological activities in microorganisms, animals and plants. Lectins from plants and animals are commonly used in direct defense against pathogens and in immune regulation. This review focuses on sources of animal and plant lectins, describing their functional classification and tridimensional structures, relating these properties with biotechnological purposes, including antimicrobial activities. In summary, this work focuses on structural-functional elucidation of diverse lectin groups, shedding some light on host-pathogen interactions; it also examines their emergence as biotechnological tools through gene manipulation and development of new drugs.

  5. Lentinula edodes Biotechnology – From Lentinan to Lectins

    Directory of Open Access Journals (Sweden)

    Valentina E. Nikitina

    2007-01-01

    Full Text Available Lentinula edodes was the first medicinal macrofungus to enter the realm of modern biotechnology. The present paper briefly reviews the history of the modern biotechnology of this mushroom starting with the production of the polysaccharide preparation lentinan, and ending with an overview of our own work regarding the production of lectins. Our work with lectins has involved studies of the effect of initial pH, carbon and nitrogen sources and the C:N ratio on lectin production in both the mycelium and culture medium. We have shown that lectin activity is related to morphological development, with the activity being highest in extracts of the pigmented mycelial films that precede fruiting body production.

  6. C-type natriuretic-derived peptides as biomarkers in human disease

    DEFF Research Database (Denmark)

    Lippert, Solvej Kølvraa; Goetze, Jens Peter

    2010-01-01

    and extracellular fluid volume. Atrial natriuretic peptide and B-type natriuretic peptide have gained considerable diagnostic interest as biomarkers in cardiovascular disease. By contrast, C-type natriuretic peptide has not yet been ascribed a role in human diagnostics. This perspective aims at recapitulating...... the present biochemical and clinical issues concerning C-type natriuretic peptide measurement in plasma as a potential biomarker....

  7. Interaction of the tobacco lectin with histone proteins

    OpenAIRE

    Schouppe, Dieter; Ghesquière, Bart; Menschaert, Gerben; De Vos, Winnok; Bourque, Stéphane; Trooskens, Geert; Proost, Paul; Gevaert, Kris; Van Damme, Els

    2011-01-01

    The tobacco (Nicotiana tabacum) agglutinin or Nictaba is a member of a novel class of plant lectins residing in the nucleus and the cytoplasm of tobacco cells. Since tobacco lectin expression is only observed after the plant has been subjected to stress situations such as jasmonate treatment or insect attack, Nictaba is believed to act as a signaling protein involved in the stress physiology of the plant. In this paper, a nuclear proteomics approach was followed to identify the binding partne...

  8. A lectin with some unique characteristics from the samta tomato.

    Science.gov (United States)

    Wang, H; Ng, T B

    2006-04-01

    A lectin, with a molecular mass of 79 kDa, and with specificity toward rhamnose and O-nitrophenyl-beta-D-galactopyranoside, was isolated from samta tomato fruits. The procedure entailed ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on CM-cellulose and gel filtration by fast protein liquid chromatography on Superdex 75. The lectin was unadsorbed on DEAE-cellulose but adsorbed on Affi-gel blue gel and CM-cellulose. The lectin was stable up to 70 degrees C. The lectin activity was potentiated by NaOH solutions (25-100 mM), but was reduced by 50 and 100 mM HCl solutions. The activity of the lectin was reduced in the presence of CaCl(2), MgCl(2) and ZnCl(2), but was potentiated by 5 and 10 mM AlCl(3) solutions. The lectin stimulated the mitogenic response in mouse splenocytes and inhibited human immunodeficiency virus-1 reverse transcriptase with an IC(50) of 6.2 microM.

  9. Domains and domain loss

    DEFF Research Database (Denmark)

    Haberland, Hartmut

    2005-01-01

    The domain concept, originally suggested by Schmidt-Rohr in the 1930’s (as credited in Fishman’s writings in the 1970s), was an attempt to sort out different areas of language use in multilingual societies, which are relevant for language choice. In Fishman’s version, domains were considered...... not described in terms of domains, and recent research e.g. about the multilingual communities in the Danish-German border area seems to confirm this....

  10. Soluble CLEC2 Extracellular Domain Improves Glucose and Lipid Homeostasis by Regulating Liver Kupffer Cell Polarization

    Directory of Open Access Journals (Sweden)

    Xinle Wu

    2015-03-01

    Full Text Available The polarization of tissue resident macrophages toward the alternatively activated, anti-inflammatory M2 phenotype is believed to positively impact obesity and insulin resistance. Here we show that the soluble form of the extracellular domain (ECD of C-type lectin-like receptor 2, CLEC2, regulates Kupffer cell polarization in the liver and improves glucose and lipid parameters in diabetic animal models. Over-expression of Fc-CLEC2(ECD in mice via in vivo gene delivery, or injection of recombinant Fc-CLEC2(ECD protein, results in a reduction of blood glucose and liver triglyceride levels and improves glucose tolerance. Furthermore, Fc-CLEC2(ECD treatment improves cytokine profiles and increases both the M2 macrophage population and the genes involved in the oxidation of lipid metabolism in the liver. These data reveal a previously unidentified role for CLEC2 as a regulator of macrophage polarity, and establish CLEC2 as a promising therapeutic target for treatment of diabetes and liver disease.

  11. Structures and binding specificity of galactose- and mannose-binding lectins from champedak: differences from jackfruit lectins.

    Science.gov (United States)

    Gabrielsen, Mads; Abdul-Rahman, Puteri Shafinaz; Othman, Shatrah; Hashim, Onn H; Cogdell, Richard J

    2014-06-01

    Galactose-binding and mannose-binding lectins from the champedak fruit, which is native to South-east Asia, exhibit useful potential clinical applications. The specificity of the two lectins for their respective ligands allows the detection of potential cancer biomarkers and monitoring of the glycosylated state of proteins in human serum and/or urine. To fully understand and expand the use of these natural proteins, their complete sequences and crystal structures are presented here, together with details of sugar binding.

  12. Molecular cloning of rhamnose-binding lectin gene and its promoter region from snakehead Channa argus.

    Science.gov (United States)

    Jia, W Z; Shang, N; Guo, Q L

    2010-09-01

    Lectins are sugar-binding proteins that mediate pathogen recognition and cell-cell interactions. A rhamnose-binding lectin (RBL) gene and its promoter region have been cloned and characterized from snakehead Channa argus. From the transcription initiation site, snakehead rhamnose-binding lectin (SHL) gene extends 2,382 bp to the end of the 3' untranslated region (UTR), and contains nine exons and eight introns. The open reading frame (ORF) of the SHL transcript has 675 bp which encodes 224 amino acids. The molecular structure of SHL is composed of two tandem repeat carbohydrate recognition domains (CRD) with 35% internal identity. Analysis of the gene organization of SHL indicates that the ancestral gene of RBL may diverge and evolve by exon shuffling and gene duplication, producing new forms to play their own roles in various organisms. The characteristics of SHL gene 5' flanking region are the presence of consensus nuclear factor of interleukin 6 (NF-IL6) and IFN-gamma activation (GAS) sites. The results provide indirect evidence that up-regulation of SHL expression may be induced in response to inflammatory stimuli, such as lipopolysaccharide (LPS), interleukin 6 (IL-6), and interferon gamma (IFN-gamma). The transcript of SHL mRNA was expressed in the head kidney, posterior kidney, spleen, liver, intestine, heart, muscle, and ovary. No tissue-specific expressive pattern is different from reported STLs, WCLs, and PFLs, suggesting that different types of RBLs exist in species-specific fish that have evolved and adapted to their surroundings.

  13. Bradykinin-potentiating peptides and C-type natriuretic peptides from snake venom.

    Science.gov (United States)

    Higuchi, S; Murayama, N; Saguchi, K; Ohi, H; Fujita, Y; Camargo, A C; Ogawa, T; Deshimaru, M; Ohno, M

    1999-10-15

    Cloning of cDNAs encoding bradykinin-potentiating peptides (BPPs)-C-type natriuretic peptide (CNP) precursor or its homologue was performed for cDNA libraries of Bothrops jararaca (South American snake), Trimeresurus flavoviridis, Trimeresurus gramineus and Agkistrodon halys blomhoffi (Asian snakes), all belonging to Crotalinae subfamily. Each cDNA library was constructed from the venom glands of a single snake to preclude ambiguity by intraspecies variation in venom components. Thirteen positive clones derived from B. jararaca were divided into two types depending on restriction sites. Differences in the nucleotide sequence arise at three locations and two of them accompanied amino acid conversions. Despite the differences, both types of cDNA clones encode the BPP-CNP precursor of 256 amino acid residues. Sequence analysis demonstrated that cDNA clones from three Asian snakes encode homologues of the BPP-CNP precursor from B. jararaca. In a precursor polypeptide, a signal sequence (approximately 25 aa) at the N-terminus is followed by sequences of BPP or the analogue (5-13 aa) with flanking spacer sequences (indefinite number of aa), an intervening linker sequence (approximately 144 aa) with unidentified function, and a CNP sequence (22 aa) with a preceding processing signal sequence (10 aa). cDNA clones from A. halys blomhoffi encode two distinct peptides in place of BPP, and T. flavoviridis and T. gramineus were shown to have considerably different sequences in the BPP domain from those known as BPP sequences. The present results provide evidence for a wide distribution of the orthologous gene expressing a series of bioactive peptides among Crotalinae subfamily.

  14. Mannan-binding lectin inhibits Candida albicans-induced cellular responses in PMA-activated THP-1 cells through Toll-like receptor 2 and Toll-like receptor 4.

    Directory of Open Access Journals (Sweden)

    Mingyong Wang

    Full Text Available BACKGROUND: Candida albicans (C. albicans, the most common human fungal pathogen, can cause fatal systemic infections under certain circumstances. Mannan-binding lectin (MBL,a member of the collectin family in the C-type lectin superfamily, is an important serum component associated with innate immunity. Toll-like receptors (TLRs are expressed extensively, and have been shown to be involved in C. albicans-induced cellular responses. We first examined whether MBL modulated heat-killed (HK C. albicans-induced cellular responses in phorbol 12-myristate 13-acetate (PMA-activated human THP-1 macrophages. We then investigated the possible mechanisms of its inhibitory effect. METHODOLOGY/PRINCIPAL FINDING: Enzyme-linked immunosorbent assay (ELISA and reverse transcriptasepolymerase chain reaction (RT-PCR analysis showed that MBL at higher concentrations (10-20 µg/ml significantly attenuated C. albicans-induced chemokine (e.g., IL-8 and proinflammatory cytokine (e.g., TNF-α production from PMA-activated THP-1 cells at both protein and mRNA levels. Electrophoretic mobility shift assay (EMSA and Western blot (WB analysis showed that MBL could inhibit C. albicans-induced nuclear factor-κB (NF-κB DNA binding and its translocation in PMA-activated THP-1 cells. MBL could directly bind to PMA-activated THP-1 cells in the presence of Ca(2+, and this binding decreased TLR2 and TLR4 expressions in C. albicans-induced THP-1 macrophages. Furthermore, the binding could be partially inhibited by both anti-TLR2 monoclonal antibody (clone TL2.1 and anti-TLR4 monoclonal antibody (clone HTA125. In addition, co-immunoprecipitation experiments and microtiter wells assay showed that MBL could directly bind to the recombinant soluble form of extracellular TLR2 domain (sTLR2 and sTLR4. CONCLUSIONS/SIGNIFICANCE: Our study demonstrates that MBL can affect proinflammatory cytokine and chemokine expressions by modifying C. albicans-/TLR-signaling pathways. This study supports

  15. cDNA cloning and expression analysis of a mannose-binding lectin from Pinellia pedatisecta

    Indian Academy of Sciences (India)

    Juan Lin; Xuanwei Zhou; Shi Gao; Xiaojun Liu; Weisheng Wu; Xiaofen Sun; Kexuan Tang

    2007-03-01

    Pinellia pedatisecta agglutinin (PPA) is a very basic protein that accumulates in the tuber of P. pedatisecta. PPA is a hetero-tetramer protein of 40 kDa, composed of two polypeptide chains A (about 12 kDa) and two polypeptides chains B (about 12 kDa). The full-length cDNA of PPA was cloned from P. pedatisecta using SMART RACE-PCR technology; it was 1146 bp and contained a 771 bp open reading frame (ORF) encoding a lectin precursor of 256 amino acid residues with a 24 amino acid signal peptide. The PPA precursor contained 3 mannose-binding sites (QXDXNXVXY) and two conserved domains of 43% identity, PPA-DOM1 (polypeptides A) and PPA-DOM2 (polypeptides B). PPA shared varying identities, ranging from 40% to 85%, with mannose-binding lectins from other species of plant families such as Araceae, Alliaceae, Iridaceae, Liliaceae, Amaryllidaceae and Bromeliaceae. Southern blot analysis indicated that ppa belonged to a multi-copy gene family. Expression pattern analysis revealed that ppa expressed in most tested tissues, with high expression being found in spadix, spathe and tuber. Cloning of the ppa gene not only provides a basis for further investigation of its structure, expression and regulatory mechanism, but also enables us to test its potential role in controlling pests and fungal diseases by transferring the gene into plants in the future.

  16. Structure predictions of two Bauhinia variegata lectins reveal patterns of C-terminal properties in single chain legume lectins.

    Science.gov (United States)

    Moreira, Gustavo M S G; Conceição, Fabricio R; McBride, Alan J A; Pinto, Luciano da S

    2013-01-01

    Bauhinia variegata lectins (BVL-I and BVL-II) are single chain lectins isolated from the plant Bauhinia variegata. Single chain lectins undergo post-translational processing on its N-terminal and C-terminal regions, which determines their physiological targeting, carbohydrate binding activity and pattern of quaternary association. These two lectins are isoforms, BVL-I being highly glycosylated, and thus far, it has not been possible to determine their structures. The present study used prediction and validation algorithms to elucidate the likely structures of BVL-I and -II. The program Bhageerath-H was chosen from among three different structure prediction programs due to its better overall reliability. In order to predict the C-terminal region cleavage sites, other lectins known to have this modification were analysed and three rules were created: (1) the first amino acid of the excised peptide is small or hydrophobic; (2) the cleavage occurs after an acid, polar, or hydrophobic residue, but not after a basic one; and (3) the cleavage spot is located 5-8 residues after a conserved Leu amino acid. These rules predicted that BVL-I and -II would have fifteen C-terminal residues cleaved, and this was confirmed experimentally by Edman degradation sequencing of BVL-I. Furthermore, the C-terminal analyses predicted that only BVL-II underwent α-helical folding in this region, similar to that seen in SBA and DBL. Conversely, BVL-I and -II contained four conserved regions of a GS-I association, providing evidence of a previously undescribed X4+unusual oligomerisation between the truncated BVL-I and the intact BVL-II. This is the first report on the structural analysis of lectins from Bauhinia spp. and therefore is important for the characterisation C-terminal cleavage and patterns of quaternary association of single chain lectins.

  17. Structure predictions of two Bauhinia variegata lectins reveal patterns of C-terminal properties in single chain legume lectins.

    Directory of Open Access Journals (Sweden)

    Gustavo M S G Moreira

    Full Text Available Bauhinia variegata lectins (BVL-I and BVL-II are single chain lectins isolated from the plant Bauhinia variegata. Single chain lectins undergo post-translational processing on its N-terminal and C-terminal regions, which determines their physiological targeting, carbohydrate binding activity and pattern of quaternary association. These two lectins are isoforms, BVL-I being highly glycosylated, and thus far, it has not been possible to determine their structures. The present study used prediction and validation algorithms to elucidate the likely structures of BVL-I and -II. The program Bhageerath-H was chosen from among three different structure prediction programs due to its better overall reliability. In order to predict the C-terminal region cleavage sites, other lectins known to have this modification were analysed and three rules were created: (1 the first amino acid of the excised peptide is small or hydrophobic; (2 the cleavage occurs after an acid, polar, or hydrophobic residue, but not after a basic one; and (3 the cleavage spot is located 5-8 residues after a conserved Leu amino acid. These rules predicted that BVL-I and -II would have fifteen C-terminal residues cleaved, and this was confirmed experimentally by Edman degradation sequencing of BVL-I. Furthermore, the C-terminal analyses predicted that only BVL-II underwent α-helical folding in this region, similar to that seen in SBA and DBL. Conversely, BVL-I and -II contained four conserved regions of a GS-I association, providing evidence of a previously undescribed X4+unusual oligomerisation between the truncated BVL-I and the intact BVL-II. This is the first report on the structural analysis of lectins from Bauhinia spp. and therefore is important for the characterisation C-terminal cleavage and patterns of quaternary association of single chain lectins.

  18. Bauhinia variegata var. variegata lectin: isolation, characterization, and comparison.

    Science.gov (United States)

    Chan, Yau Sang; Ng, Tzi Bun

    2015-01-01

    Bauhinia variegata var. variegata seeds are rich in proteins. Previously, one of the major storage proteins of the seeds was found to be a trypsin inhibitor that possessed various biological activities. By using another purification protocol, a glucoside- and galactoside-binding lectin that demonstrated some differences from the previously reported B. variegata lectin could be isolated from the seeds. It involved affinity chromatography on Affi-gel blue gel, ion exchange chromatography on Q-Sepharose and Mono Q, and also size exclusion chromatography on Superdex 75. The lectin was not retained on Affi-gel blue gel but interacted with Q-Sepharose. The lectin was a 64-kDa protein with two 32-kDa subunits. It had low thermostability (stable up to 50 °C) and moderate pH stability (stable in pH 3-10). It exhibited anti-proliferative activity on nasopharyngeal carcinoma HONE1 cells with an IC50 of 12.8 μM after treatment for 48 h. It also slightly inhibited the growth of hepatoma HepG2 cells. The lectin may have potential in aiding cancer treatments.

  19. The interaction of fish trypanosome culture forms with some lectins.

    Science.gov (United States)

    Zajícek, P; Pecková, H

    1990-01-01

    The interactions of fish trypanosome culture forms with 11 purified lectins were compared using the agglutination test in microwell plates. Altogether, ten stocks of ten different freshwater fish species were examined. Three basic types of cell-lectin interactions were observed on the microscopical level. The strong agglutination of all stocks regardless their original host was found in the presence of Con A, PSA, RCA60, and RCA120, which implies the presence of relatively high amounts of sugar residues of D-mannose and D-galactose in the surface of culture forms of these parasites. Weak agglutinations of some stocks were observed in the presence of LCA, PNA, SBA, and WGA lectins, but their low intensity makes them not sufficiently reliable for stock characterization. The lectins UEA I, HPA, and PHA caused no agglutination. In conclusion, in case of unequivocal results no remarkable differences in the interactions of various stocks of trypanosomes culture forms with used lectins were observed. These results imply the high degree of similarity of their main cell surface saccharide structures.

  20. Effects of Plant Lectins on Human Erythrocyte Agglutination

    Directory of Open Access Journals (Sweden)

    Zubcevic Nadja

    2016-09-01

    Full Text Available Plant lectins are carbohydrate binding proteins or phytohaemagglutinins present in most plants, especially seeds and tubers, which include cereals, potatoes and beans. Lectins have great significance in the diet because of their involvement in gastrointestinal difficulties and erythrocyte agglutination. Blood agglutination activity against A, B, AB and O groups was shown after exposing blood to extracts obtained from 55% of tested plants, while in 45% of plants, agglutination was absent. The results of our study have shown that in humans, 40% of plant extracts exhibited activity against A, 40% of plant extracts exhibited activity against B, and 50% of plant extracts exhibited activity against AB and O groups in humans. The concentration of plant lectins depends on the part of the plant. Lectins from the seeds of certain plants cause the greatest percentage of erythrocyte agglutination, while the lowest agglutination was caused by plant bulbs and leaves. However, lectins derived from all plant species of the family Fabaceae agglutinated erythrocytes of all blood types to some extent.

  1. Lectin Activity in Gut Extract of Culex pipiens.

    Directory of Open Access Journals (Sweden)

    Mona Koosha

    2013-06-01

    Full Text Available The role of lectins is important in interaction between pathogens and mosquito vectors. This study was performed to identify agglutinin activities of protein molecules on the midgut of Culex pipiens.Culex pipiens was reared in insectray condition and the midguts of males and females (blood fed and unfed were dissected separately in Tris-HCl buffer. The extracts of midguts were applied for hemagglutinin assay against red blood cells of rabbit, mouse, rat, dog, horse, sheep, guinea pig, cow, human (A, B, AB, O groups. Then, the RBCs with relatively high agglutinin activity were chosen for carbohydrate inhibition assay. D (+ glucose, D (+ galactose, D (+ mannose, D (- fructose, D (- arabinose, L (- fucose, lactose, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, sialic acid were used to specify carbohydrate binding lectin.The highest agglutinin activities were found against sheep and rabbits RBCs. Sexual diversity of agglutinin activities was observed among midgut extraction of males and females. In addition, variation in agglutinin activity of blood fed and unfed female mosquitoes were detected. The lectin activity was inhibited highly with glucose, galactose, fucose and fructose but less inhibitor activities was observed by arabinose, N-acetyl-D-galactosamine, n-acetyl-d-glucosamine, lactose and mannose.The secretion of hemagglutinins (lectins or lectin-like molecules in the digestive system depends on the type of food in the gut. This suggests that emptying of the gut in preparation for protein rich food probably starts the secretion of hemagglutinins.

  2. A Rhizobium leguminosarum CHDL- (Cadherin-Like-) Lectin Participates in Assembly and Remodeling of the Biofilm Matrix

    Science.gov (United States)

    Vozza, Nicolás F.; Abdian, Patricia L.; Russo, Daniela M.; Mongiardini, Elías J.; Lodeiro, Aníbal R.; Molin, Søren; Zorreguieta, Angeles

    2016-01-01

    In natural environments most bacteria live in multicellular structures called biofilms. These cell aggregates are enclosed in a self-produced polymeric extracellular matrix, which protects the cells, provides mechanical stability and mediates cellular cohesion and adhesion to surfaces. Although important advances were made in the identification of the genetic and extracellular factors required for biofilm formation, the mechanisms leading to biofilm matrix assembly, and the roles of extracellular proteins in these processes are still poorly understood. The symbiont Rhizobium leguminosarum requires the synthesis of the acidic exopolysaccharide and the PrsDE secretion system to develop a mature biofilm. PrsDE is responsible for the secretion of the Rap family of proteins that share one or two Ra/CHDL (cadherin-like-) domains. RapA2 is a calcium-dependent lectin with a cadherin-like β sheet structure that specifically recognizes the exopolysaccharide, either as a capsular polysaccharide (CPS) or in its released form [extracellular polysaccharide (EPS)]. In this study, using gain and loss of function approaches combined with phenotypic and microscopic studies we demonstrated that RapA lectins are involved in biofilm matrix development and cellular cohesion. While the absence of any RapA protein increased the compactness of bacterial aggregates, high levels of RapA1 expanded distances between cells and favored the production of a dense matrix network. Whereas endogenous RapA(s) are predominantly located at one bacterial pole, we found that under overproduction conditions, RapA1 surrounded the cell in a way that was reminiscent of the capsule. Accordingly, polysaccharide analyses showed that the RapA lectins promote CPS formation at the expense of lower EPS production. Besides, polysaccharide analysis suggests that RapA modulates the EPS size profile. Collectively, these results show that the interaction of RapA lectins with the polysaccharide is involved in rhizobial

  3. Fucose-binding lectin from opportunistic pathogen Burkholderia ambifaria binds to both plant and human oligosaccharidic epitopes.

    Science.gov (United States)

    Audfray, Aymeric; Claudinon, Julie; Abounit, Saïda; Ruvoën-Clouet, Nathalie; Larson, Göran; Smith, David F; Wimmerová, Michaela; Le Pendu, Jacques; Römer, Winfried; Varrot, Annabelle; Imberty, Anne

    2012-02-03

    Burkholderia ambifaria is generally associated with the rhizosphere of plants where it has biocontrol effects on other microorganisms. It is also a member of the Burkholderia cepacia complex, a group of closely related bacteria that cause lung infections in immunocompromised patients as well as in patients with granulomatous disease or cystic fibrosis. Our previous work indicated that fucose on human epithelia is a frequent target for lectins and adhesins of lung pathogens (Sulák, O., Cioci, G., Lameignère, E., Balloy, V., Round, A., Gutsche, I., Malinovská, L., Chignard, M., Kosma, P., Aubert, D. F., Marolda, C. L., Valvano, M. A., Wimmerová, M., and Imberty, A. (2011) PLoS Pathog. 7, e1002238). Analysis of the B. ambifaria genome identified BambL as a putative fucose-binding lectin. The 87-amino acid protein was produced recombinantly and demonstrated to bind to fucosylated oligosaccharides with a preference for αFuc1-2Gal epitopes. Crystal structures revealed that it associates as a trimer with two fucose-binding sites per monomer. The overall fold is a six-bladed β-propeller formed by oligomerization as in the Ralstonia solanacearum lectin and not by sequential domains like the fungal fucose lectin from Aleuria aurantia. The affinity of BambL for small fucosylated glycans is very high as demonstrated by microcalorimetry (K(D) < 1 μM). Plant cell wall oligosaccharides and human histo-blood group oligosaccharides H-type 2 and Lewis Y are bound with equivalent efficiency. Binding to artificial glycosphingolipid-containing vesicles, human saliva, and lung tissues confirmed that BambL could recognize a wide spectrum of fucosylated epitopes, albeit with a lower affinity for biological material from nonsecretor individuals.

  4. Lectin receptor kinases participate in protein-protein interactions to mediate plasma membrane-cell wall adhesions in Arabidopsis.

    Science.gov (United States)

    Gouget, Anne; Senchou, Virginie; Govers, Francine; Sanson, Arnaud; Barre, Annick; Rougé, Pierre; Pont-Lezica, Rafael; Canut, Hervé

    2006-01-01

    Interactions between plant cell walls and plasma membranes are essential for cells to function properly, but the molecules that mediate the structural continuity between wall and membrane are unknown. Some of these interactions, which are visualized upon tissue plasmolysis in Arabidopsis (Arabidopsis thaliana), are disrupted by the RGD (arginine-glycine-aspartic acid) tripeptide sequence, a characteristic cell adhesion motif in mammals. In planta induced-O (IPI-O) is an RGD-containing protein from the plant pathogen Phytophthora infestans that can disrupt cell wall-plasma membrane adhesions through its RGD motif. To identify peptide sequences that specifically bind the RGD motif of the IPI-O protein and potentially play a role in receptor recognition, we screened a heptamer peptide library displayed in a filamentous phage and selected two peptides acting as inhibitors of the plasma membrane RGD-binding activity of Arabidopsis. Moreover, the two peptides also disrupted cell wall-plasma membrane adhesions. Sequence comparison of the RGD-binding peptides with the Arabidopsis proteome revealed 12 proteins containing amino acid sequences in their extracellular domains common with the two RGD-binding peptides. Eight belong to the receptor-like kinase family, four of which have a lectin-like extracellular domain. The lectin domain of one of these, At5g60300, recognized the RGD motif both in peptides and proteins. These results imply that lectin receptor kinases are involved in protein-protein interactions with RGD-containing proteins as potential ligands, and play a structural and signaling role at the plant cell surfaces.

  5. Lectin Receptor Kinases Participate in Protein-Protein Interactions to Mediate Plasma Membrane-Cell Wall Adhesions in Arabidopsis1

    Science.gov (United States)

    Gouget, Anne; Senchou, Virginie; Govers, Francine; Sanson, Arnaud; Barre, Annick; Rougé, Pierre; Pont-Lezica, Rafael; Canut, Hervé

    2006-01-01

    Interactions between plant cell walls and plasma membranes are essential for cells to function properly, but the molecules that mediate the structural continuity between wall and membrane are unknown. Some of these interactions, which are visualized upon tissue plasmolysis in Arabidopsis (Arabidopsis thaliana), are disrupted by the RGD (arginine-glycine-aspartic acid) tripeptide sequence, a characteristic cell adhesion motif in mammals. In planta induced-O (IPI-O) is an RGD-containing protein from the plant pathogen Phytophthora infestans that can disrupt cell wall-plasma membrane adhesions through its RGD motif. To identify peptide sequences that specifically bind the RGD motif of the IPI-O protein and potentially play a role in receptor recognition, we screened a heptamer peptide library displayed in a filamentous phage and selected two peptides acting as inhibitors of the plasma membrane RGD-binding activity of Arabidopsis. Moreover, the two peptides also disrupted cell wall-plasma membrane adhesions. Sequence comparison of the RGD-binding peptides with the Arabidopsis proteome revealed 12 proteins containing amino acid sequences in their extracellular domains common with the two RGD-binding peptides. Eight belong to the receptor-like kinase family, four of which have a lectin-like extracellular domain. The lectin domain of one of these, At5g60300, recognized the RGD motif both in peptides and proteins. These results imply that lectin receptor kinases are involved in protein-protein interactions with RGD-containing proteins as potential ligands, and play a structural and signaling role at the plant cell surfaces. PMID:16361528

  6. Mannose binding lectin plays a crucial role in innate immunity against yeast by enhanced complement activation and enhanced uptake of polymorphonuclear cells

    Directory of Open Access Journals (Sweden)

    Herpers Bjorn L

    2008-12-01

    Full Text Available Abstract Background Mannose binding lectin (MBL is an important host defence protein against opportunistic fungal pathogens. This carbohydrate-binding protein, an opsonin and lectin pathway activator, binds through multiple lectin domains to the repeating sugar arrays displayed on the surface of a wide range of clinically relevant microbial species. We investigated the contribution of MBL to antifungal innate immunity towards C. parapsilosis in vitro. Results High avidity binding was observed between MBL and C. albicans and C. parapsilosis. Addition of MBL to MBL deficient serum increased the deposition of C4 and C3b and enhanced the uptake of C. albicans, C. parapsilosis and acapsular C. neoformans by polymorphonuclear cells (PMNs. Compared to other microorganisms, such as Escherichia coli, Staphylococcus aureus and Cryptococcus neoformans, C. parapsilosis and Candida albicans were potent activators of the lectin pathway. Conclusion Our results suggest that MBL plays a crucial role in the innate immunity against infections caused by yeast by increasing uptake by PMN.

  7. Marine Sponge Lectins: Actual Status on Properties and Biological Activities

    Directory of Open Access Journals (Sweden)

    Sandro Mascena Gomes Filho

    2014-12-01

    Full Text Available Marine sponges are primitive metazoans that produce a wide variety of molecules that protect them against predators. In studies that search for bioactive molecules, these marine invertebrates stand out as promising sources of new biologically-active molecules, many of which are still unknown or little studied; thus being an unexplored biotechnological resource of high added value. Among these molecules, lectins are proteins that reversibly bind to carbohydrates without modifying them. In this review, various structural features and biological activities of lectins derived from marine sponges so far described in the scientific literature are discussed. From the results found in the literature, it could be concluded that lectins derived from marine sponges are structurally diverse proteins with great potential for application in the production of biopharmaceuticals, especially as antibacterial and antitumor agents.

  8. BSA-boronic acid conjugate as lectin mimetics.

    Science.gov (United States)

    Narla, Satya Nandana; Pinnamaneni, Poornima; Nie, Huan; Li, Yu; Sun, Xue-Long

    2014-01-10

    We report bovine serum albumin (BSA)-boronic acid (BA) conjugates as lectin mimetics and their glyco-capturing capacity. The BSA-BA conjugates were synthesized by amidation of carboxylic acid groups in BSA with aminophenyl boronic acid in the presence of EDC, and were characterized by Alizarin Red S (ARS) assay and SDS-PAGE gel. The BSA-BA conjugates were immobilized onto maleimide-functionalized silica beads and their sugar capturing capacity and specificity were confirmed by ARS displacement assay. Further, surface plasmon resonance (SPR) analysis of the glyco-capturing activity of the BSA-BA conjugates was conducted by immobilizing BSA-BA onto SPR gold chip. Overall, we demonstrated a BSA-BA-based lectin mimetics for glyco-capturing applications. These lectin mimetics are expected to provide an important tool for glycomics and biosensor research and applications.

  9. Isolation and Biochemical Characterization of Apios Tuber Lectin

    Directory of Open Access Journals (Sweden)

    Eri Kenmochi

    2015-01-01

    Full Text Available Apios tuber lectin, named ATL, was isolated from Apios americana Medikus by two chromatography steps, hydrophobic chromatography and anion-exchange chromatography. The minimum concentration required for the hemagglutination activity toward rabbit erythrocytes of ATL was 4 μg/mL. ATL was composed of a homodimer of 28.4 kDa subunits. The amino acid sequence of ATL was similar to those of other legume lectins. The lectin showed moderate stability toward heating and acidic pH, and the binding affinity against several monosaccharides, such as D-glucosamine and D-galactosamine. ATL also bound to desialylated or agalactosylated glycoproteins such as asialo and agalacto transferrin. ATL decreased the transepithelial electrical resistance across human intestinal Caco-2 cell monolayers, suggesting the effect on the tight junction-mediated paracellular transport.

  10. Parkia pendula lectin as histochemistry marker for meningothelial tumour

    Directory of Open Access Journals (Sweden)

    EIC Beltrão

    2009-06-01

    Full Text Available Lectins have been intensively used in histochemical techniques for cell surface characterization. These proteins are involved in several biological processes and their use as histochemical markers have been evaluated since they can indicate differences in cell surfaces. Parkia pendula lectin (PpeL was evaluated as histochemical marker for meningothelial meningioma biopsies. Tissue slices were incubated with PpeL conjugated to horseradish peroxidase (PpeL-HRP and Concanavalin A-HRP (ConA-HPR and the binding visualized with diaminobenzidine and hydrogen peroxide. The lectin-tissue binding was inhibited with D-glucose. PpeL showed to be a useful tool for the characterization of meningothelial tumour and clinico-pathological diagnosis.

  11. Production and purification of active snowdrop lectin in Escherichia coli.

    Science.gov (United States)

    Longstaff, M; Powell, K S; Gatehouse, J A; Raemaekers, R; Newell, C A; Hamilton, W D

    1998-02-15

    Recombinant snowdrop lectin was produced in Escherichia coli from a cDNA clone encoding mature Galanthus nivalis agglutinin. After induction with isopropylthio-beta-D-galactoside, inclusion bodies from E. coli were solubilised and the G. nivalis agglutinin purified by metal-affinity chromatography using a carboxy-terminal hexahistidine tag. The protein was refolded on the metal-affinity column prior to elution. After purification, the recombinant G. nivalis agglutinin agglutinated rabbit erythrocytes to a dilution similar to that determined for 'native' lectin purified from snowdrop, and showed similar specific binding to mannose. The toxicity of the recombinant G. nivalis agglutinin towards rice brown planthopper (Nilaparvata lugens) was shown to be similar to that of 'native' G. nivalis agglutinin when incorporated into an artificial diet. The recombinant G. nivalis agglutinin is thus functionally similar to 'native' snowdrop lectin.

  12. Erythrina lectins detect the H/HI blood groups.

    Science.gov (United States)

    Sudakevitz, D; Gilboa-Garber, N; Levene, C; Sela, R; Bhattacharyya, L

    1991-08-01

    The lectin purified from Erythrina corallodendron seeds which binds N-acetyllactosamine greater than N-acetyl-D-galactosamine greater than alpha and beta galactosides greater than D-galactose was examined for its ABO(H) blood group specificity. It has been shown that this lectin causes the strongest hemagglutination of O(H) and weakest of Oh(Bombay) red blood cells, and interacts with the H antigen in association with the I antigen. The reactions of Erythrina corallodendron and Erythrina indica lectins (which are similar in sugar specificity) with erythrocytes of different ABO(H) and Ii blood groups (the I bloods were all from adults and the i from either cord or adult bloods) revealed the following order of activity: O(H)I greater than A2 I greater than O(H)i adult greater than A2BI greater than BI greater than O(H)i cord greater than A1I greater than A1i adult greater than Bi cord greater than A1BI greater than Ai cord greater than ABi cord greater than OhI. The Erythrina indica lectin showed a lower differentiation between the agglutination of O(H) and Oh erythrocytes. Both Erythrina lectins exhibited H/HI blood group preference but were not inhibited by the saliva from ABO(H) "secretors". Thus they may be classified with the Cytisus sessilifolius, Lotus tetragonolobus and Laburnum alpinum lectins which are inhibited by lactose but not by H blood group substances in secretions.

  13. Bi- to tetravalent glycoclusters presenting GlcNAc/GalNAc as inhibitors: from plant agglutinins to human macrophage galactose-type lectin (CD301) and galectins.

    Science.gov (United States)

    André, Sabine; O'Sullivan, Shane; Koller, Christiane; Murphy, Paul V; Gabius, Hans-Joachim

    2015-04-14

    Emerging insights into the functional spectrum of tissue lectins leads to identification of new targets for the custom-made design of potent inhibitors, providing a challenge for synthetic chemistry. The affinity and selectivity of a carbohydrate ligand for a lectin may immensely be increased by a number of approaches, which includes varying geometrical or topological features. This perspective leads to the design and synthesis of glycoclusters and their testing using assays of physiological relevance. Herein, hydroquinone, resorcinol, benzene-1,3,5-triol and tetra(4-hydroxyphenyl)ethene have been employed as scaffolds and propargyl derivatives obtained. The triazole-containing linker to the α/β-O/S-glycosides of GlcNAc/GalNAc presented on these scaffolds was generated by copper-catalysed azide-alkyne cycloaddition. This strategy was used to give a panel of nine glycoclusters with bi-, tri- and tetravalency. Maintained activity for lectin binding after conjugation was ascertained for both sugars in solid-phase assays with the plant agglutinins WGA (GlcNAc) and DBA (GalNAc). Absence of cross-reactivity excluded any carbohydrate-independent reactivity of the bivalent compounds, allowing us to proceed to further testing with a biomedically relevant lectin specific for GalNAc. Macrophage galactose(-binding C)-type lectin, involved in immune defence by dendritic cells and in virus uptake, was produced as a soluble protein without/with its α-helical coiled-coil stalk region. Binding to ligands presented on a matrix and on cell surfaces was highly susceptible to the presence of the tetravalent inhibitor derived from the tetraphenylethene-containing scaffold, and presentation of GalNAc with an α-thioglycosidic linkage proved favorable. Cross-reactivity of this glycocluster to human galectins-3 and -4, which interact with Tn-antigen-presenting mucins, was rather small. Evidently, the valency and spatial display of α-GalNAc residues is a key factor to design potent and

  14. INTERACTION BETWEEN THE SURFACE GLYCOSYLATED POLYPROPYLENE MEMBRANE AND LECTIN

    Institute of Scientific and Technical Information of China (English)

    Qian Yang; Ling-shu Wan; Zhi-kang Xu

    2008-01-01

    A glycopolymer bearing glucose residues was tethered onto the surface of polypropylene microporous membrane by UV-induced graft polymerization of α-allyl glucoside. Concanavalin A (Con A), a glucose recognizing lectin, could be specifically adsorbed to the membrane surface. On the other hand, the membrane surface showed no recognition ability to another lectin peanut agglutinin. Moreover, the recognition complex between the glycosylated membrane surface and Con Acould be inhibited by glucose and mannose solution. This surface glycosylated membrane could be used as affinity membrane for protein separation and purification.

  15. Ribosome-inactivating lectins with polynucleotide:adenosine glycosidase activity.

    Science.gov (United States)

    Battelli, M G; Barbieri, L; Bolognesi, A; Buonamici, L; Valbonesi, P; Polito, L; Van Damme, E J; Peumans, W J; Stirpe, F

    1997-05-26

    Lectins from Aegopodium podagraria (APA), Bryonia dioica (BDA), Galanthus nivalis (GNA), Iris hybrid (IRA) and Sambucus nigra (SNAI), and a new lectin-related protein from Sambucus nigra (SNLRP) were studied to ascertain whether they had the properties of ribosome-inactivating proteins (RIP). IRA and SNLRP inhibited protein synthesis by a cell-free system and, at much higher concentrations, by cells and had polynucleotide:adenosine glycosidase activity, thus behaving like non-toxic type 2 (two chain) RIP. APA and SNAI had much less activity, and BDA and GNA did not inhibit protein synthesis.

  16. Ferromagnetic Levan Composite: An Affinity Matrix to Purify Lectin

    Directory of Open Access Journals (Sweden)

    Renata Angeli

    2009-01-01

    Full Text Available A simple and inexpensive procedure used magnetite and levan to synthesize a composite recovered by a magnetic field. Lectins from Canavalia ensiformis (Con A and Cratylia mollis (Cramoll 1 and Cramoll 1,4 did bind specifically to composite. The magnetic property of derivative favored washing out contaminating proteins and recovery of pure lectins with glucose elution. Cramoll 1 was purified by this affinity binding procedure in two steps instead of a previous three-step protocol with ammonium sulfate fractionation, affinity chromatography on Sephadex G-75, and ion exchange chromatography through a CM-cellulose column.

  17. Mannan-binding lectin activates C3 and the

    DEFF Research Database (Denmark)

    Selander, B.; Martensson, U.; Weintraub, A.;

    2006-01-01

    Lectin pathway activation of C3 is known to involve target recognition by mannan-binding lectin (MBL) or ficolins and generation of classical pathway C3 convertase via cleavage of C4 and C2 by MBL-associated serine protease 2 (MASP-2). We investigated C3 activation in C2-deficient human sera...... and in sera with other defined defects of complement to assess other mechanisms through which MBL might recruit complement. The capacity of serum to support C3 deposition was examined by ELISA using microtiter plates coated with O antigen-specific oligosaccharides derived from Salmonella typhimurium, S...

  18. 树突状细胞相关凝集素受体1和2在真菌免疫领域的研究进展%DC-associated C-type lecxin-1 and DC-associated C-type lecxin-2 in antifungal dfences

    Institute of Scientific and Technical Information of China (English)

    黄晓强; 陈剑

    2012-01-01

    树突状细胞相关凝集素受体1和2(Dectin1和2)是2C型凝集素受体家族(CLR)的重要成员,作为模式识别受体( PRRs),其有效地识别病原体相关分子模式(PAMPs);Dectin-1识别β-葡聚糖,通过自身免疫受体络氨酸激活基序( ITAM)向胞内转导信号;Dectin-2识别α-甘露聚糖,通过耦联FcRγ链上的ITAM结构转导信号.ITAM招募并激活非受体络氨酸蛋白激酶(Syk),后者激活MAPKs或介导CARD9-Malt1-Bcl10复合体组装,激活核因子-κB(NF-κB),诱导合成炎症因子等一系列细胞活动.其配体β-葡聚糖和甘露聚糖都是真菌细胞壁的主要成分.近年来研究表明,Dectin-1和Dectin-2受体在真菌免疫防御中具有重要作用.%DC-associated C-type lectin-1 and 2 (Dectin-1 and Dectin-2) are pivotal C-type lectin family members,both of them function as pattern recognition receptors (PRRs) to initiate innate and adaptive immunity by recognizing pathogen-associated molecular patterns (PAMPs).Dectin-1 recognizes β-glucans and signals with its cytoplasmic immunoreceptor tyrosine-based activation motif (ITAM)-like motif,whereas Dectin-2 recognizes α-mannans and signals through association with the ITAM-containing Fc receptor γ chain.Upon ligand ligation,spleen tyrosine kinase (Syk) is recruited to the ITAM.Syk mediates the activation of MAPKs;or induces the formation of the CARD9-Malt1-Bcl10 complex,resulting in the activation of nuclear factor-κB (NF-κB).Recert studies indicate that Dectin-1 and Dectin-2 play important roles in immune defense against fungi.

  19. Galactose/N-acetylgalactosamine lectin: the coordinator of host cell killing

    Indian Academy of Sciences (India)

    Douglas R Boettner; Christopher Huston; William A Petri Jr

    2002-11-01

    Entamoeba histolytica is an enteric parasite that can kill host cells via a contact-dependent mechanism. This killing involves the amoebic surface protein referred to as the Gal/GalNAc lectin. The Gal/GalNAc lectin binds galactose and N-acetylgalactosamine allowing the adherence of amoebas to host cells. Involvement of the lectin in the pathogenesis of E. histolytica infection will be reviewed in this paper. The lectin has been shown to have very specific and substantial effects on adherence, cytotoxicity, and encystation. There is also possible involvement of the lectin in phagocytosis and caspase activation in host cells.

  20. Genetic influences on mannan-binding lectin (MBL) and mannan-binding lectin associated serine protease-2 (MASP-2) activity

    DEFF Research Database (Denmark)

    Sørensen, GL; Petersen, I; Thiel, Steffen;

    2007-01-01

    The lectin pathway of the complement system is activated when Mannan-binding lectin (MBL) in complex with MASP-2 binds microorganisms. Polymorphisms in both genes are responsible for low serum levels, which associate with increased risk of infection and autoimmune disease. The present study....... Heritabilites of MBL levels and MASP-2 activity were estimated using structural equation modeling allowing assessment of the contribution of common genes affecting both traits. The estimated heritability was 0.77 [95% CI 0.64;0.91] for MBL levels and 0.75 [95% CI 0.59;0.81] for MASP-2 activity with the presence...

  1. Genetic influences on mannan-binding lectin (MBL) and mannan-binding lectin associated serine protease-2 (MASP-2) activity

    DEFF Research Database (Denmark)

    Sørensen, Grith Lykke; Petersen, Inge; Thiel, Steffen;

    2007-01-01

    The lectin pathway of the complement system is activated when Mannan-binding lectin (MBL) in complex with MASP-2 binds microorganisms. Polymorphisms in both genes are responsible for low serum levels, which associate with increased risk of infection and autoimmune disease. The present study...... of additive genetic factors, shared environmental factors, and non-shared environmental factors. The genetic correlation, i.e., common genetic factors affecting MBL and MASP-2 activity was estimated to r(g) = 0.34 [0.25;0.42]. The data indicate a strong genetic influence for the serum levels of MBL...

  2. Lectin coated MgO nanoparticle: its toxicity, antileishmanial activity, and macrophage activation.

    Science.gov (United States)

    Jebali, Ali; Hekmatimoghaddam, Seyedhossein; Kazemi, Bahram; Allaveisie, Azra; Masoudi, Alireza; Daliri, Karim; Sedighi, Najme; Ranjbari, Javad

    2014-10-01

    The purpose of this research was to evaluate toxicity of uncoated magnesium oxide nanoparticles (MgO NPs), MgO NPs coated with Peanut agglutinin (PNA) lectin, and PNA alone on the promastigotes of Leishmania major (L. major) and macrophages of BALB/c mice. On the other hand, antileishmanial property of uncoated MgO NPs, lectin coated MgO NPs, and PNA lectin alone was evaluated, and also macrophage activation was investigated after treatment with these materials by measurement of nitrite, H2O2, and some interleukins. This study showed that PNA lectin and lectin coated MgO NPs had approximately no toxicity on L. major and macrophages, but some toxic effects were observed for uncoated MgO NPs, especially at concentration of 500 µg/mL. Interestingly, lectin coated MgO NPs had the highest antileishmanial activity and macrophage activation, compared with uncoated MgO NPs and PNA lectin.

  3. Lectin from Canavalia brasiliensis Seeds (ConBr Is a Valuable Biotechnological Tool to Stimulate the Growth of Rhizobium tropici in Vitro

    Directory of Open Access Journals (Sweden)

    Ricardo Pires dos Santos

    2012-05-01

    Full Text Available To study the interactions between a Rhizobium tropici strain and lectins isolated from the seeds of Canavalia ensiformis (ConA and Canavalia brasiliensis (ConBr, a lectin fluorescence assay was performed. In addition, an experiment was designed to evaluate the effect of the two lectins on bacterial growth. Both lectins were found to bind to R. tropici cells, but the interactions were inhibited by D-mannose. Interestingly, only ConBr stimulated bacterial growth in proportion to the concentrations used (15.6–500 µg/mL, and the bacterial growth stimulation was inhibited by D-mannose as well. Structure/Function analyses by bioinformatics were carried out to evaluate the volume and carbohydrate recognition domain (CRD configuration of ConA and ConBr. The difference of spatial arrangement and volume of CRD may indicate the variation between biological activities of both lectins. The results suggest that ConBr could be a promising tool for studies focusing on the interactions between rhizobia and host plants.

  4. A hypothesis on the origin of C-type asteroids and carbonaceous chondrites

    OpenAIRE

    Busarev, V. V.

    2012-01-01

    A hypothesis based on observational and theoretical results on the origin of C-type asteroids and carbonaceous chondrites is proposed. Asteroids of C-type and close BGF-types could form from hydrated silicate-organic matter accumulated in the cores of water-differentiated (due to 26Al and other short-lived isotopes decay) bodies existed in the growth zones of Jupiter. Gravitational scattering of such bodies by Jupiter at its final stage of formation to the main asteroid belt might have led to...

  5. Characterization of glycoconjugates of extracellular polymeric substances in tufa-associated biofilms by using fluorescence lectin-binding analysis.

    Science.gov (United States)

    Zippel, B; Neu, T R

    2011-01-01

    Freshwater tufa deposits are the result of calcification associated with biofilms dominated by cyanobacteria. Recent investigations highlighted the fact that the formation of microbial calcium carbonates is mainly dependent on the saturation index, which is determined by pH, the ion activity of Ca(2+) and CO(3)(2-), and the occurrence of extracellular polymeric substances (EPS) produced by microorganisms. EPS, which contain carboxyl and/or hydroxyl groups, can strongly bind cations. This may result in inhibition of CaCO(3) precipitation. In contrast, the formation of templates for crystal nucleation was reported by many previous investigations. The purposes of this study were (i) to characterize the in situ distribution of EPS glycoconjugates in tufa-associated biofilms of two German hard-water creeks by employing fluorescence lectin-binding analysis (FLBA), (ii) to verify the specific lectin-binding pattern by competitive-inhibition assays, and (iii) to assess whether carbonates are associated with structural EPS domains. Three major in situ EPS domains (cyanobacterial, network-like, and cloud-like structures) were detected by FLBA in combination with laser scanning microscopy (LSM). Based on lectin specificity, the EPS glycoconjugates produced by cyanobacteria contained mainly fucose, amino sugars (N-acetyl-glucosamine and N-acetyl-galactosamine), and sialic acid. Tufa deposits were irregularly covered by network-like EPS structures, which may originate from cyanobacterial EPS secretions. Cloud-like EPS glycoconjugates were dominated by sialic acid, amino sugars, and galactose. In some cases calcium carbonate crystals were associated with cyanobacterial EPS glycoconjugates. The detection of amino sugars and calcium carbonate in close association with decaying sheath material indicated that microbially mediated processes might be important for calcium carbonate precipitation in freshwater tufa systems.

  6. Expression Analysis of Lily Type Lectin Isotypes in the Rock Bream, Oplegnathus fasciatus: in the Tissue, Developmental Stage and Viral Infection.

    Science.gov (United States)

    Lee, Young Mee; Yang, In Jung; Noh, Jae Koo; Kim, Hyun Chul; Park, Choul-Ji; Park, Jong-Won; Noh, Gyeong Eon; Kim, Woo-Jin; Kim, Kyung-Kil

    2016-12-01

    Lectins belong to the pattern-recognition receptors (PRRs) class and play important roles in the recognition and elimination of pathogens via the innate immune system. Recently, it was reported that lily-type lectin-1 is involved when a pathogen attacks in the early immune response of fish. However, this study is limited to information that the lectin is involved in the innate immune response against viral infection. In the present study, the lily-type lectin-2 and -3 of Oplegnathus fasciatus (OfLTL-2 and 3) have been presented to be included B-lectin domain and two D-mannose binding sites in the amino acid sequence that an important feature for the fundamental structure. To investigate the functional properties of OfLTLs, the tissue distribution in the healthy rock bream and temporal expression during early developmental stage analysis are performed using quantitative real-time PCR. OfLTL-2 and 3 are predominantly expressed in the liver and skin, but rarely expressed in other organ. Also, the transcripts of OfLTLs are not expressed during the early developmental stage but its transcripts are increased after immune-related organs which are fully formed. In the challenge experiment with RBIV (rock bream iridovirus), the expression of OfLTLs was increased much more strongly in the late response than the early, unlike previously known. These results suggest that OfLTLs are specifically expressed in the immune-related tissues when those organs are fully formed and it can be inferred that the more intensively involved in the second half to the virus infection.

  7. Mannose-Binding Lectin Deficiency Is Associated with Myocardial Infarction

    DEFF Research Database (Denmark)

    Vengen, Inga Thorsen; Madsen, Hans O; Garred, Peter;

    2012-01-01

    Mannose-binding lectin (MBL) and ficolins activate the complement cascade, which is involved in atherogenesis. Based on a pilot study, we hypothesized that functional polymorphisms in the MBL gene (MBL2) leading to dysfunctional protein are related to development of myocardial infarction (MI...

  8. Lectin Activity in Gut Extract of Culex Pipiens

    Directory of Open Access Journals (Sweden)

    Mona Koosha

    2013-03-01

    Full Text Available Background: The role of lectins is important in interaction between pathogens and mosquito vectors. This study was performed to identify agglutinin activities of protein molecules on the midgut of Culex pipiens. Methods: Culex pipiens was reared in insectray condition and the midguts of males and females (blood fed and un­fed were dissected separately in Tris-HCl buffer. The extracts of midguts were applied for hemagglutinin assay against red blood cells of rabbit, mouse, rat, dog, horse, sheep, guinea pig, cow, human (A, B, AB, O groups. Then, the RBCs with relatively high agglutinin activity were chosen for carbohydrate inhibition assay. D (+ glucose, D (+ galactose, D (+ mannose, D (- fructose, D (- arabinose, L (- fucose, lactose, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, sialic acid were used to specify carbohydrate binding lectin.Results: The highest agglutinin activities were found against sheep and rabbits RBCs. Sexual diversity of agglutinin activities was observed among midgut extraction of males and females. In addition, variation in agglutinin activity of blood fed and unfed female mosquitoes were detected. The lectin activity was inhibited highly with glucose, galactose, fucose and fructose but less inhibitor activities was observed by arabinose, N-acetyl-D-galactosamine, n-acetyl-d-glucosamine, lactose and mannose.Conclusion: The secretion of hemagglutinins (lectins or lectin-like molecules in the digestive system depends on the type of food in the gut. This suggests that emptying of the gut in preparation for protein rich food probably starts the secretion of hemagglutinins.

  9. Broad spectrum activity of a lectin-like bacterial serine protease family on human leukocytes.

    Directory of Open Access Journals (Sweden)

    Jorge Luis Ayala-Lujan

    Full Text Available The serine protease autotransporter from Enterobacteriaceae (SPATE family, which number more than 25 proteases with apparent diverse functions, have been phylogenetically divided into two distinct classes, designated 1 and 2. We recently demonstrated that Pic and Tsh, two members of the class-2 SPATE family produced by intestinal and extraintestinal pathogenic E. coli, were able to cleave a number of O-glycosylated proteins on neutrophils and lymphocytes resulting in impaired leukocyte functions. Here we show that most members of the class-2 SPATE family have lectin-like properties and exhibit differential protease activity reliant on glycoprotein type and cell lineage. Protease activity was seen in virtually all tested O-glycosylated proteins including CD34, CD55, CD164, TIM1, TIM3, TIM4 and C1-INH. We also show that although SPATE proteins bound and cleaved glycoproteins more efficiently on granulocytes and monocytes, they also targeted glycoproteins on B, T and natural killer lymphocytes. Finally, we found that the characteristic domain-2 of class-2 SPATEs is not required for glycoprotease activity, but single amino acid mutations in Pic domain-1 to those residues naturally occurring in domain-1 of SepA, were sufficient to hamper Pic glycoprotease activity. This study shows that most class-2 SPATEs have redundant activities and suggest that they may function as immunomodulators at several levels of the immune system.

  10. Mannan-binding lectin and mannan-binding lectin-associated serine protease 2 in acute pancreatitis

    DEFF Research Database (Denmark)

    Novovic, Srdan; Andersen, Anders Møller; Ersbøll, Annette Kjær;

    2011-01-01

    Complement activation may play a prominent role in acute pancreatitis (AP). Mannan-binding lectin (MBL) and MBL-associated serine protease 2 (MASP-2) participate in complement activation. The objective of the present study was to evaluate the role of MBL and MASP-2 as markers in AP with regard to...... to etiology, inflammatory activity, severity, and development of multiorgan failure....

  11. Processing-independent analysis for pro-C-type natriuretic peptide

    DEFF Research Database (Denmark)

    Lippert, Solvej Kølvraa; Rehfeld, Jens F.; Gøtze, Jens Peter

    2010-01-01

    C-type natriuretic peptide (CNP) is expressed in several human tissues. We designed a specific processing-independent assay for proCNP-derived products and quantitated the concentrations in human seminal plasma from normal and vasectomized men. Antibodies were raised against the N-terminus of human...

  12. Functional environmental proteomics: elucidating the role of a c-type cytochrome abundant during uranium bioremediation.

    Science.gov (United States)

    Yun, Jiae; Malvankar, Nikhil S; Ueki, Toshiyuki; Lovley, Derek R

    2016-02-01

    Studies with pure cultures of dissimilatory metal-reducing microorganisms have demonstrated that outer-surface c-type cytochromes are important electron transfer agents for the reduction of metals, but previous environmental proteomic studies have typically not recovered cytochrome sequences from subsurface environments in which metal reduction is important. Gel-separation, heme-staining and mass spectrometry of proteins in groundwater from in situ uranium bioremediation experiments identified a putative c-type cytochrome, designated Geobacter subsurface c-type cytochrome A (GscA), encoded within the genome of strain M18, a Geobacter isolate previously recovered from the site. Homologs of GscA were identified in the genomes of other Geobacter isolates in the phylogenetic cluster known as subsurface clade 1, which predominates in a diversity of Fe(III)-reducing subsurface environments. Most of the gscA sequences recovered from groundwater genomic DNA clustered in a tight phylogenetic group closely related to strain M18. GscA was most abundant in groundwater samples in which Geobacter sp. predominated. Expression of gscA in a strain of Geobacter sulfurreducens that lacked the gene for the c-type cytochrome OmcS, thought to facilitate electron transfer from conductive pili to Fe(III) oxide, restored the capacity for Fe(III) oxide reduction. Atomic force microscopy provided evidence that GscA was associated with the pili. These results demonstrate that a c-type cytochrome with an apparent function similar to that of OmcS is abundant when Geobacter sp. are abundant in the subsurface, providing insight into the mechanisms for the growth of subsurface Geobacter sp. on Fe(III) oxide and suggesting an approach for functional analysis of other Geobacter proteins found in the subsurface.

  13. Isolation and partial characterization of a lectin from ground elder (Aegopodium podagraria) rhizomes.

    Science.gov (United States)

    Peumans, W J; Nsimba-Lubaki, M; Peeters, B; Broekaert, W F

    1985-05-01

    A lectin has been isolated from rhizomes of ground elder (Aegopodium podagraria) using a combination of affinity chromatography on erythrocyte membrane proteins immobilized on cross-linked agarose and hydroxyapatite, and ion-exchange chromatography. The molecular structure of the lectin was determined by gelfiltration, sucrose density-gradient centrifugation and gel electrophoresis under denaturing conditions. It has an unusually high Mr (about 480000) and is most probably an octamer composed of two distinct types of subunits with slightly different Mr (about 60000). Hapten inhibition assays indicated that the Aegopodium lectin is preferentially inhibited by N-acetylgalactosamine. Nevertheless, it does not agglutinate preferentially blood-group-A erythrocytes. The ground-elder lectin is a typical non-seed lectin, which occurs virtually exclusively in the underground rhizomes. In this organ it is an abundant protein as it represents up to 5% of the total protein content. The lectin content of the rhizome tissue varies strongly according to its particular location along the organ. In addition, the lectin content changes dramatically as a function of the seasons. The ground-elder lectin differs from all other plant lectins by its unusually high molecular weight. In addition, it is the first lectin to be isolated from a species of the family Apiaceae.

  14. The galactophilic lectin (PA-IL, gene LecA) from Pseudomonas aeruginosa. Its binding requirements and the localization of lectin receptors in various mouse tissues

    DEFF Research Database (Denmark)

    Kirkeby, Svend; Hansen, Axel K; d'Apice, Anthony

    2006-01-01

    . It is concluded that the carbohydrate recognizing site of the lectin can have a binding requirement of only one saccharide. Lectin histochemistry was performed on sections from wild type mice and from knock-out mice, which lack function of the alpha.1,3-galactosyltransferase gene. All assays with the P...

  15. Mannan-binding lectin and healing of a radiation-induced chronic ulcer--a case report on mannan-binding lectin replacement therapy

    DEFF Research Database (Denmark)

    Maaløe, Nanna; Bonde, C; Laursen, I;

    2011-01-01

    Mannan-binding lectin is an important component of innate immunity, and insufficiency is associated with several clinical disorders. Recently, experimental replacement therapy with plasma-derived mannan-binding lectin has become an option. The current article presents the case of a patient with a...

  16. cDNA and Gene Structure of MytiLec-1, A Bacteriostatic R-Type Lectin from the Mediterranean Mussel (Mytilus galloprovincialis).

    Science.gov (United States)

    Hasan, Imtiaj; Gerdol, Marco; Fujii, Yuki; Rajia, Sultana; Koide, Yasuhiro; Yamamoto, Daiki; Kawsar, Sarkar M A; Ozeki, Yasuhiro

    2016-01-01

    MytiLec is an α-d-galactose-binding lectin with a unique primary structure isolated from the Mediterranean mussel (Mytilus galloprovincialis). The lectin adopts a β-trefoil fold that is also found in the B-sub-unit of ricin and other ricin-type (R-type) lectins. We are introducing MytiLec(-1) and its two variants (MytiLec-2 and -3), which both possess an additional pore-forming aerolysin-like domain, as members of a novel multi-genic "mytilectin family" in bivalve mollusks. Based on the full length mRNA sequence (911 bps), it was possible to elucidate the coding sequence of MytiLec-1, which displays an extended open reading frame (ORF) at the 5' end of the sequence, confirmed both at the mRNA and at the genomic DNA sequence level. While this extension could potentially produce a polypeptide significantly longer than previously reported, this has not been confirmed yet at the protein level. MytiLec-1 was revealed to be encoded by a gene consisting of two exons and a single intron. The first exon comprised the 5'UTR and the initial ATG codon and it was possible to detect a putative promoter region immediately ahead of the transcription start site in the MytiLec-1 genomic locus. The remaining part of the MytiLec-1 coding sequence (including the three sub-domains, the 3'UTR and the poly-A signal) was included in the second exon. The bacteriostatic activity of MytiLec-1 was determined by the agglutination of both Gram-positive and Gram-negative bacteria, which was reversed by the co-presence of α-galactoside. Altogether, these data support the classification of MytiLec-1 as a member of the novel mytilectin family and suggest that this lectin may play an important role as a pattern recognition receptor in the innate immunity of mussels.

  17. Lectin receptors on the plasma membrane of soybean cells. Binding and lateral diffusion of lectins.

    Science.gov (United States)

    Metcalf, T N; Wang, J L; Schubert, K R; Schindler, M

    1983-08-02

    Protoplasts prepared from suspension cultures of root cells of Glycine max (SB-1 cell line) bound soybean agglutinin (SBA), concanavalin A (Con A), and wheat germ agglutinin (WGA). Binding studies carried out with 125I-labeled SBA, Con A, and WGA showed that these interactions were saturable and specific. Fluorescence microscopy demonstrated uniform membrane labeling. The mobility of the lectin-receptor complexes was measured by fluorescence redistribution after photobleaching. The diffusion constants (D) for SBA and Con A were 5 X 10(-11) and 7 X 10(-11) cm2/s, respectively. In contrast, WGA yielded a diffusion constant of 3 X 10(-10) cm2/s. Pretreatment of the protoplasts with either SBA or Con A resulted in a 6-fold reduction in the mobility of WGA (D congruent to 5 X 10(-11) cm2/s). The results suggest that the binding of SBA or Con A may lead to alterations of the soybean plasma membrane which, in turn, may restrict the mobility of other receptors.

  18. PO-20 - Crosstalk between the lectin pathway and haemostasis in patients with pulmonary cancer

    DEFF Research Database (Denmark)

    Larsen, J B; Christensen, T D; Hvas, C L

    2016-01-01

    INTRODUCTION: Recent research has focused on the complement system in cancer, including the lectin pathway of complement activation. Mannose-binding lectin (MBL), a key activator of the lectin pathway, can bind to tumor cell surfaces in vitro, and lectin pathway activation is increased in several...... types of cancer. The exact role of the complement system in cancer is currently discussed. However, one possible consequence of the increased complement activation could be contribution to the increased thrombosis risk which cancer patients experience. Proteins of the lectin pathway can activate...... coagulation and impair fibrinolysis in vitro, but the significance of this in a clinical setting is not well understood. AIM: We aim to investigate associations between lectin pathway and haemostatic activation in patients with lung cancer undergoing thoracoscopic surgery. MATERIALS AND METHODS: Patients...

  19. A galactose-specific lectin from the hemolymph of the pearl oyster, Pinctada fucata martensii.

    Science.gov (United States)

    Suzuki, T; Mori, K

    1989-01-01

    1. A lectin in the serum of Pinctada fucata martensii was purified by a combination of affinity chromatography on Sepharose 4B coupled with bovine submaxillary gland mucine, anion exchange chromatography on Mono Q and gel filtration on Superose 6. 2. The purified lectin was indicated to be homogeneous by polyacrylamide electrophoresis and rechromatography on Mono Q. 3. The purified lectin was approximately 440,000 in molecular weight and was composed of identical subunits with a molecular weight of approximately 20,000. 4. D-galactose and N-acetylgalactosamine gave a 50% inhibition of agglutination of horse erythrocytes by the lectin at 0.3 and 1.2 mM, respectively. 5. The antibody obtained from rabbit immunized with the purified lectin was monospecific to the lectin judged from the hemagglutination blocking test, immunoelectrophoresis and immunoblotting.

  20. Lectin Activation in Giardia lamblia by Host Protease: A Novel Host-Parasite Interaction

    Science.gov (United States)

    Lev, Boaz; Ward, Honorine; Keusch, Gerald T.; Pereira, Miercio E. A.

    1986-04-01

    A lectin in Giardia lamblia was activated by secretions from the human duodenum, the environment where the parasite lives. Incubation of the secretions with trypsin inhibitors prevented the appearance of lectin activity, implicating proteases as the activating agent. Accordingly, lectin activation was also produced by crystalline trypsin and Pronase; other proteases tested were ineffective. When activated, the lectin agglutinated intestinal cells to which the parasite adheres in vivo. The lectin was most specific to mannose-6-phosphate and apparently was bound to the plasma membrane. Activation of a parasite lectin by a host protease represents a novel mechanism of hostparasite interaction and may contribute to the affinity of Giardia lamblia to the infection site.

  1. Transient evolution of C-type shocks in dusty regions of varying density

    CERN Document Server

    Ashmore, I; Caselli, P; Falle, S A E G; Hartquist, T W

    2009-01-01

    Outflows of young stars drive shocks into dusty, molecular regions. Most models of such shocks assume that they are steady and propagating perpendicular to the magnetic field. Real shocks often violate both of these assumptions and the media through which they propagate are inhomogeneous. We use the code employed previously to produce the first time-dependent simulations of fast-mode, oblique C-type shocks interacting with density perturbations. We include a self-consistent calculation of the thermal and ionisation balances and a fluid treatment of grains. We identify features that develop when a multifluid shock encounters a density inhomogeneity to investigate whether any part of the precursor region ever behaves in a quasi-steady fashion. If it does the shock may be modelled approximately without solving the time-dependent hydromagnetic equations. Simulations were made for initially steady oblique C-type shocks encountering density inhomogeneities. For a semi-finite inhomogeneity with a density larger than...

  2. Large Scale Magnetic Separation of Solanum tuberosum Tuber Lectin from Potato Starch Waste Water

    Science.gov (United States)

    Safarik, Ivo; Horska, Katerina; Martinez, Lluis M.; Safarikova, Mirka

    2010-12-01

    A simple procedure for large scale isolation of Solanum tuberosum tuber lectin from potato starch industry waste water has been developed. The procedure employed magnetic chitosan microparticles as an affinity adsorbent. Magnetic separation was performed in a flow-through magnetic separation system. The adsorbed lectin was eluted with glycine/HCl buffer, pH 2.2. The specific activity of separated lectin increased approximately 27 times during the isolation process.

  3. Griffithsin: An Antiviral Lectin with Outstanding Therapeutic Potential

    Directory of Open Access Journals (Sweden)

    Sabrina Lusvarghi

    2016-10-01

    Full Text Available Griffithsin (GRFT, an algae-derived lectin, is one of the most potent viral entry inhibitors discovered to date. It is currently being developed as a microbicide with broad-spectrum activity against several enveloped viruses. GRFT can inhibit human immunodeficiency virus (HIV infection at picomolar concentrations, surpassing the ability of most anti-HIV agents. The potential to inhibit other viruses as well as parasites has also been demonstrated. Griffithsin’s antiviral activity stems from its ability to bind terminal mannoses present in high-mannose oligosaccharides and crosslink these glycans on the surface of the viral envelope glycoproteins. Here, we review structural and biochemical studies that established mode of action and facilitated construction of GRFT analogs, mechanisms that may lead to resistance, and in vitro and pre-clinical results that support the therapeutic potential of this lectin.

  4. Gliadins bind to reticulin in a lectin-like manner.

    Science.gov (United States)

    Unsworth, D J; Leonard, J N; Hobday, C M; Griffiths, C E; Powles, A V; Haffenden, G P; Fry, L

    1987-01-01

    It has previously been reported that gliadins bind to reticulin in tissue sections. Three lines of evidence are reported in this study which indicate that the gliadins bind to reticulins because they are lectins which bind to sugars expressed on glycoproteins in reticulin and other sites. First, immunofluorescence studies on tissue sections showed that although gliadin binding is largely confined to areas rich in reticulin, it is, nonetheless, also seen in one or two other sites devoid of reticulin. Second, by using fluorescein-labelled lectins of known specificity, it has been shown that the areas to which gliadins bind in tissue sections (including those sites devoid of reticulin) are rich in particular sugars. Third, it has been shown that one of these sugars, alpha-D-mannose, partially inhibited gliadin binding to tissue sections.

  5. Soluble Host Defense Lectins in Innate Immunity to Influenza Virus

    Directory of Open Access Journals (Sweden)

    Wy Ching Ng

    2012-01-01

    Full Text Available Host defenses against viral infections depend on a complex interplay of innate (nonspecific and adaptive (specific components. In the early stages of infection, innate mechanisms represent the main line of host defense, acting to limit the spread of virus in host tissues prior to the induction of the adaptive immune response. Serum and lung fluids contain a range of lectins capable of recognizing and destroying influenza A viruses (IAV. Herein, we review the mechanisms by which soluble endogenous lectins mediate anti-IAV activity, including their role in modulating IAV-induced inflammation and disease and their potential as prophylactic and/or therapeutic treatments during severe IAV-induced disease.

  6. Sequence-Based Appraisal of the Genes Encoding Neck and Carbohydrate Recognition Domain of Conglutinin in Blackbuck (Antilope cervicapra and Goat (Capra hircus

    Directory of Open Access Journals (Sweden)

    Sasmita Barik

    2014-01-01

    Full Text Available Conglutinin, a collagenous C-type lectin, acts as soluble pattern recognition receptor (PRR in recognition of pathogens. In the present study, genes encoding neck and carbohydrate recognition domain (NCRD of conglutinin in goat and blackbuck were amplified, cloned, and sequenced. The obtained 488 bp ORFs encoding NCRD were submitted to NCBI with accession numbers KC505182 and KC505183. Both nucleotide and predicted amino acid sequences were analysed with sequences of other ruminants retrieved from NCBI GenBank using DNAstar and Megalign5.2 software. Sequence analysis revealed maximum similarity of blackbuck sequence with wild ruminants like nilgai and buffalo, whereas goat sequence displayed maximum similarity with sheep sequence at both nucleotide and amino acid level. Phylogenetic analysis further indicated clear divergence of wild ruminants from the domestic ruminants in separate clusters. The predicted secondary structures of NCRD protein in goat and blackbuck using SWISSMODEL ProtParam online software were found to possess 6 beta-sheets and 3 alpha-helices which are identical to the result obtained in case of sheep, cattle, buffalo, and nilgai. However, quaternary structure in goat, sheep, and cattle was found to differ from that of buffalo, nilgai, and blackbuck, suggesting a probable variation in the efficiency of antimicrobial activity among wild and domestic ruminants.

  7. Annotation and genetic diversity of the chicken collagenous lectins.

    Science.gov (United States)

    Hamzić, Edin; Pinard-van der Laan, Marie-Hélène; Bed'Hom, Bertrand; Juul-Madsen, Helle Risdahl

    2015-06-01

    Collectins and ficolins are multimeric proteins present in various tissues and are actively involved in innate immune responses. In chickens, six different collagenous lectins have been characterized so far: mannose-binding lectin (MBL), surfactant protein A (SP-A), collectin 10 (COLEC10), collectin 11 (COLEC11), collectin 12 (COLEC12), lung lectin (LL) and one ficolin (FCN). However, the structural and functional features of the chicken collectins and ficolin are still not fully understood. Therefore, the aims of this study were: (i) to make an overview of the genetic structure and function of chicken collectins and the ficolin, (ii) to investigate the variation in the chicken collectins and the ficolin gene in different chicken populations, and (iii) to assess the presence of MBL gene variants in different chicken populations. We performed comparative genomic analysis using publically available data. The obtained results showed that collectins and ficolins have conserved protein sequences and gene structure across all vertebrate groups and this is especially notable for COLEC10, COLEC11 and COLEC12. For the purpose of studying the genetic variation, 179 animals from 14 populations were genotyped using 31 SNPs covering five genomic regions. The obtained results revealed low level of heterozygosity in the collagenous lectins except for the COLEC12 gene and the LL-SPA-MBL region compared to heterozygosity at neutral microsatellite markers. In addition, the MBL gene variants were assessed in different chicken populations based on the polymorphisms in the promoter region. We observed 10 previously identified MBL variants with A2/A8 and A4 as the most frequent alleles.

  8. Molecular recognition of surface-immobilized carbohydrates by a synthetic lectin

    Directory of Open Access Journals (Sweden)

    Melanie Rauschenberg

    2014-06-01

    Full Text Available The molecular recognition of carbohydrates and proteins mediates a wide range of physiological processes and the development of synthetic carbohydrate receptors (“synthetic lectins” constitutes a key advance in biomedical technology. In this article we report a synthetic lectin that selectively binds to carbohydrates immobilized in a molecular monolayer. Inspired by our previous work, we prepared a fluorescently labeled synthetic lectin consisting of a cyclic dimer of the tripeptide Cys-His-Cys, which forms spontaneously by air oxidation of the monomer. Amine-tethered derivatives of N-acetylneuraminic acid (NANA, β-D-galactose, β-D-glucose and α-D-mannose were microcontact printed on epoxide-terminated self-assembled monolayers. Successive prints resulted in simple microarrays of two carbohydrates. The selectivity of the synthetic lectin was investigated by incubation on the immobilized carbohydrates. Selective binding of the synthetic lectin to immobilized NANA and β-D-galactose was observed by fluorescence microscopy. The selectivity and affinity of the synthetic lectin was screened in competition experiments. In addition, the carbohydrate binding of the synthetic lectin was compared with the carbohydrate binding of the lectins concanavalin A and peanut agglutinin. It was found that the printed carbohydrates retain their characteristic selectivity towards the synthetic and natural lectins and that the recognition of synthetic and natural lectins is strictly orthogonal.

  9. Characterization of a new lectin involved in the protoplast regeneration of Bryopsis hypnoides

    Institute of Scientific and Technical Information of China (English)

    NIU Jianfeng; WANG Guangce; L(U) Fang; ZHOU Baicheng; PENG Guang

    2009-01-01

    A group of coenocytic marine algae differs from higher plants, whose totipotency depends on an intact cell (or protoplast). Instead, this alga is able to aggregate its extruded protoplasm in sea water and generate new mature individuals. It is thought that lectins play a key role in the aggregation process. We purified a lectin associated with the aggregation of cell organelles in Bryopsis hypnoides. The lectin was ca. 27 kDa with a pI between pH 5 and pH 6. The absence of carbohydrate suggested that the lectin was not a glycoprotein. The hemagglutinating activity (HA) of the lectin was not dependent on the presence of divalent cations and was inhibited by N-Acetylgalactosamine, N-Acetylglucosamine, and the glycoprotein bovine submaxillary mucin. The lectin preferentially agglutinated Gram-negative bacterium. The HA of this lectin was stable between pH 4 to pH 10. Cell organelles outside the cytoplasm were agglutinated by the addition of lectin solution (0.5 mg ml-1). Our results suggest that the regeneration of B. hypnoides is mediated by this lectin. We also demonstrated that the formation of cell organelle aggregates was inhibited by nigericin in natural seawater (pH 8.0). Given that nigericin dissipates proton gradients across the membrane, we hypothesize that the aggregation of cell organelles was proton-gradient dependent.

  10. Prevention of intestinal amebiasis by vaccination with the Entamoeba histolytica Gal/GalNac lectin.

    Science.gov (United States)

    Houpt, Eric; Barroso, Lisa; Lockhart, Lauren; Wright, Rhonda; Cramer, Carole; Lyerly, David; Petri, William A

    2004-01-26

    Prevention of intestinal infection by Entamoeba histolytica would block both invasive disease and parasite transmission. The amebic Gal/GalNAc lectin mediates parasite adherence to the colonic surface and fecal anti-lectin IgA is associated with protection from intestinal reinfection in children. We tested if vaccination with the E. histolytica Gal/GalNAc lectin could prevent cecal infection in a C3H mouse model of amebic colitis. Two trials using native lectin purified from the parasite and two trials using a 64 kDa recombinant fragment ("LecA") were performed with a combined intranasal and intraperitoneal immunization regimen using cholera toxin and Freund's adjuvants, respectively. Two weeks after immunization mice were challenged intracecally with trophozoites, and 4-12 weeks after challenge mice were sacrificed for histopathologic evaluation of infection. Vaccination prevented intestinal infection with efficacies of 84 and 100% in the two native lectin trials and 91 and 34% in the two LecA trials. Mice with detectable pre-challenge fecal anti-lectin IgA responses were significantly more resistant to infection than mice without fecal anti-lectin IgA responses. These results show for the first time that immunization with the Gal/GalNAc lectin can prevent intestinal amebiasis in mice and suggest a protective role for fecal anti-lectin IgA in vivo.

  11. A simple fibril and lectin model for cyst walls of Entamoeba and perhaps Giardia.

    Science.gov (United States)

    Samuelson, John; Robbins, Phillips

    2011-01-01

    Cyst walls of Entamoeba and Giardia protect them from environmental insults, stomach acids, and intestinal proteases. Each cyst wall contains a sugar homopolymer: chitin in Entamoeba and a unique N-acetylgalactosamine (GalNAc) homopolymer in Giardia. Entamoeba cyst wall proteins include Jacob lectins (carbohydrate-binding proteins) that crosslink chitin, chitinases that degrade chitin, and Jessie lectins that make walls impermeable. Giardia cyst wall proteins are also lectins that bind fibrils of the GalNAc homopolymer. Although many of the details remain to be determined for the cyst wall of Giardia, current data suggest a relatively simple fibril and lectin model for the Entamoeba cyst wall.

  12. Microencapsulation of lectin anti-cancer agent and controlled release by alginate beads, biosafety approach.

    Science.gov (United States)

    El-Aassar, M R; Hafez, Elsayed E; El-Deeb, Nehal M; Fouda, Moustafa M G

    2014-08-01

    Hepatocellular carcinoma (HCC) is considered as one of the most aggressive cancer worldwide. In Egypt, the prevalence of HCC is increasing during last years. Recently, drug-loaded microparticles were used to improve the efficiency of various medical treatments. This study is designed to evaluate the anticancer potentialities of lectins against HCC while hinting to its safety usage. The aim is also extended to encapsulate lectins in alginate microbeads for oral drug delivery purposes. The extracted lectins showed anti-proliferative effect against HCC with a percentage of 60.76% by using its nontoxic dose with an up-regulation of P53 gene expression. Concerning the handling of lectin alginate microbeads for oral drug delivery, the prepared lectin alginate beads were ∼100μm in diameter. The efficiency of the microcapsules was checked by scanning electron microscopy, the SEM showed the change on the alginate beads surface revealing the successful lectin encapsulation. The release of lectins from the microbeads depended on a variety of factors as the microbeads forming carriers and the amount-encapsulated lectins. The Pisum sativum extracted lectins may be considered as a promising agent in controlling HCC and this solid dosage form could be suitable for oral administration complemented with/or without the standard HCC drugs.

  13. Mouse macrophage galactose-type lectin (mMGL) is critical for host resistance against Trypanosoma cruzi infection.

    Science.gov (United States)

    Vázquez, Alicia; Ruiz-Rosado, Juan de Dios; Terrazas, Luis I; Juárez, Imelda; Gomez-Garcia, Lorena; Calleja, Elsa; Camacho, Griselda; Chávez, Ana; Romero, Miriam; Rodriguez, Tonathiu; Espinoza, Bertha; Rodriguez-Sosa, Miriam

    2014-01-01

    The C-type lectin receptor mMGL is expressed exclusively by myeloid antigen presenting cells (APC) such as dendritic cells (DC) and macrophages (Mφ), and it mediates binding to glycoproteins carrying terminal galactose and α- or β-N-acetylgalactosamine (Gal/GalNAc) residues. Trypanosoma cruzi (T. cruzi) expresses large amounts of mucin (TcMUC)-like glycoproteins. Here, we show by lectin-blot that galactose moieties are also expressed on the surface of T. cruzi. Male mMGL knockout (-/-) and wild-type (WT) C57BL/6 mice were infected intraperitoneally with 10(4) T. cruzi trypomastigotes (Queretaro strain). Following T. cruzi infection, mMGL-/- mice developed higher parasitemia and higher mortality rates compared with WT mice. Although hearts from T. cruzi-infected WT mice presented few amastigote nests, mMGL-/- mice displayed higher numbers of amastigote nests. Compared with WT, Mφ from mMGL-/- mice had low production of nitric oxide (NO), interleukin (IL)-12 and tumor necrosis factor (TNF)-α in response to soluble T. cruzi antigens (TcAg). Interestingly, upon in vitro T. cruzi infection, mMGL-/- Mφ expressed lower levels of MHC-II and TLR-4 and harbored higher numbers of parasites, even when mMGL-/- Mφ were previously primed with IFN-γ or LPS/IFN-γ. These data suggest that mMGL plays an important role during T. cruzi infection, is required for optimal Mφ activation, and may synergize with TLR-4-induced pathways to produce TNF-α, IL-1β and NO during the early phase of infection.

  14. Regional differences in lectin binding patterns of vestibular hair cells

    Science.gov (United States)

    Baird, Richard A.; Schuff, N. R.; Bancroft, J.

    1994-01-01

    Surface glycoconjugates of hair cells and supporting cells in the vestibular endorgans of the bullfrog were identified using biotinylated lectins with different carbohydrate specificities. Lectin binding in hair cells was consistent with the presence of glucose and mannose (CON A), galactose (RCA-I), N-acetylgalactosamine (VVA), but not fucose (UEA-I) residues. Hair cells in the bullfrog sacculus, unlike those in the utriculus and semicircular canals, did not stain for N-acetylglucosamine (WGA) or N-acetylgalactosamine (VVA). By contrast, WGA and, to a lesser extent, VVA, differentially stained utricular and semicircular canal hair cells, labeling hair cells located in peripheral, but not central, regions. In mammals, WGA uniformly labeled Type 1 hair cells while labeling, as in the bullfrog, Type 2 hair cells only in peripheral regions. These regional variations were retained after enzymatic digestion. We conclude that vestibular hair cells differ in their surface glycoconjugates and that differences in lectin binding patterns can be used to identify hair cell types and to infer the epithelial origin of isolated vestibular hair cells.

  15. Ganoderma lucidum: a source for novel bioactive lectin.

    Science.gov (United States)

    U Girjal, Vinay; Neelagund, Shivayogeeswar; Krishnappa, Madappa

    2011-11-01

    Ganoderma lucidum is known for its high medicinal value, clinically used in treatment for various diseases. We have selected this mushroom for isolation of novel bioactive lectin. The isolation procedure comprised of ion-exchange chromatography on DEAE- cellulose and affinity chromatography on Affi-gel blue gel. Purified lectin was monomer with a molecular mass of 15 kDa, determined by SDS-PAGE, Gel filtration, MALDI-ToF. It showed hemagglutinating activity against both human and animal erythrocytes. The hemagglutination activity was not inhibited by simple sugars but inhibited by glycoproteins. The activity was maximal at pH range 4.0-9.0 and at temperature up to 60° C. The hemagglutination activity was stable even in the presence of 10mM EDTA and other divalent metal cations such as CaCl2, MgCl2, ZnCl2, and MnCl2. Lectin was shown antifungal activity against following pathogens Fusarium oxysporium, Penicillium chrysogenum, Aspergillus Niger, Colletotrichum musae, Botrytis cinerea, Trichophyton rubrum, Trichophyton tonsurans, Trichophyton interdigitale, Epidermophyton floccosum and Microsporum canis.

  16. Labeling of lectin receptors during the cell cycle.

    Science.gov (United States)

    Garrido, J

    1976-12-01

    Labeling of lectin receptors during the cell cycle. (Localizabión de receptores para lectinas durante el ciclo celular). Arch. Biol. Med. Exper. 10: 100-104, 1976. The topographic distribution of specific cell surface receptors for concanavalin A and wheat germ agglutinin was studied by ultrastructural labeling in the course of the cell cycle. C12TSV5 cells were synchronized by double thymidine block or mechanical selection (shakeoff). They were labeled by means of lectin-peroxidase techniques while in G1 S, G2 and M phases of the cycle. The results obtained were similar for both lectins employed. Interphase cells (G1 S, G2) present a stlihtly discontinous labeling pattern that is similar to the one observed on unsynchronized cells of the same line. Cells in mitosis, on the contrary, present a highly discontinous distribution of reaction product. This pattern disappears after the cells enters G1 and is not present on mitotic cells fixed in aldehyde prior to labeling.

  17. TFPI inhibits lectin pathway of complement activation by direct interaction with MASP-2.

    Science.gov (United States)

    Keizer, Mischa P; Pouw, Richard B; Kamp, Angela M; Patiwael, Sanne; Marsman, Gerben; Hart, Margreet H; Zeerleder, Sacha; Kuijpers, Taco W; Wouters, Diana

    2015-02-01

    The lectin pathway (LP) of complement has a protective function against invading pathogens. Recent studies have also shown that the LP plays an important role in ischemia/reperfusion (I/R)-injury. MBL-associated serine protease (MASP)-2 appears to be crucial in this process. The serpin C1-inhibitor is the major inhibitor of MASP-2. In addition, aprotinin, a Kunitz-type inhibitor, was shown to inhibit MASP-2 activity in vitro. In this study we investigated whether the Kunitz-type inhibitor tissue factor pathway inhibitor (TFPI) is also able to inhibit MASP-2. Ex vivo LP was induced and detected by C4-deposition on mannan-coated plates. The MASP-2 activity was measured in a fluid-phase chromogenic assay. rTFPI in the absence or presence of specific monoclonal antibodies was used to investigate which TFPI-domains contribute to MASP-2 inhibition. Here, we identify TFPI as a novel selective inhibitor of MASP-2, without affecting MASP-1 or the classical pathway proteases C1s and C1r. Kunitz-2 domain of TFPI is required for the inhibition of MASP-2. Considering the role of MASP-2 in complement-mediated I/R-injury, the inhibition of this protease by TFPI could be an interesting therapeutic approach to limit the tissue damage in conditions such as cerebral stroke, myocardial infarction or solid organ transplantation.

  18. Structure of mannose-specific snowdrop (Galanthus nivalis) lectin is representative of a new plant lectin family.

    Science.gov (United States)

    Hester, G; Kaku, H; Goldstein, I J; Wright, C S

    1995-06-01

    Tetrameric Galanthus nivalis agglutinin (50,000 M(r)) belongs to a super-family of alpha-D-mannose-specific plant bulb lectins known to be potent inhibitors of retroviruses. The 2.3 A crystal structure of this lectin complexed with methyl alpha-D-mannose reveals a novel three-fold symmetric beta-sheet polypeptide fold. Three antiparallel four-stranded beta-sheets, each with a conserved mannose-binding site, are arranged as a 12-stranded beta-barrel. The tetramer displays 222 symmetry. Pairs of monomers form stable dimers through C-terminal strand exchange. The so formed hybrid beta-sheets are the sites for high affinity mannose binding in the dimer interface. Occupancy observed at corresponding sites in other beta-sheets suggests a potential for twelve sites per tetramer.

  19. Polymorphisms in the Mannose-Binding Lectin Gene are Associated with Defective Mannose-Binding Lectin Functional Activity in Crohn's Disease Patients.

    Science.gov (United States)

    Choteau, Laura; Vasseur, Francis; Lepretre, Frederic; Figeac, Martin; Gower-Rousseau, Corine; Dubuquoy, Laurent; Poulain, Daniel; Colombel, Jean-Frederic; Sendid, Boualem; Jawhara, Samir

    2016-01-01

    Mannose-binding lectin, together with mannose-associated serine proteases, activates the lectin pathway of the complement system and subsequent inflammatory mechanisms. An association between mannose-binding lectin deficiency and anti-Saccharomyces cerevisiae antibody levels is observed in Crohn's disease and this deficiency is frequently associated with a severe Crohn's disease phenotype. In the present study, we assessed the relationship between serum concentrations of mannose-binding lectin, mannose-binding lectin functional activity, MBL2 and NOD2 polymorphisms, anti-S. cerevisiae antibody levels and clinical Crohn's disease phenotype in 69 Crohn's disease patients and 30 age- and sex-matched healthy controls. The results show that the MBL2 variant rs5030737 at codon 52 was associated with a low level of mannose-binding lectin and impaired mannose-binding lectin-mannose-associated serine protease (MBL-MASP) functional activity in Crohn's disease patients. This MBL2 variant was also associated with a higher level of anti-S. cerevisiae antibodies. In addition, the NOD2 variant rs2066844, which is associated with susceptibility to Crohn's disease, was significantly correlated with an impairment in MBL-MASP functional activity. These results provide evidence that Crohn's disease patients have an impairment in MBL-MASP functional activity and that this defect is associated with MBL2 and NOD2 variants.

  20. Functional characterization of mannose-binding lectin in zebrafish: implication for a lectin-dependent complement system in early embryos.

    Science.gov (United States)

    Yang, Lili; Bu, Lingzhen; Sun, Weiwei; Hu, Lili; Zhang, Shicui

    2014-10-01

    The lectin pathway involves recognition of pathogen-associated molecular patterns by mannose-binding lectin (MBL), and the subsequent activation of associated enzymes, termed MBL-associated serine proteases (MASPs). In this study, we demonstrate that the transcript of MBL gene is present in the early embryo of zebrafish, and MBL protein is also present in the embryo. In addition, we show that recombinant zebrafish MBL was able to bind the Gram-negative bacterium Escherichia coli and the Gram-positive bacterium Staphylococcus aureus, and rMBL was able to promote the phagocytosis of E. coli and S. aureus by macrophages, indicating that like mammalian MBL, zebrafish MBL performs a dual function in both pattern recognition and opsonization. Importantly, we show that microinjection of anti-MBL antibody into the early developing embryos resulted in a significantly increased mortality in the embryos challenged with Aeromonas hydrophila (pathogenic to zebrafish); and injection of rMBL into the embryos (resulting in increase in MBL in the embryo) markedly promoted their resistance to A. hydrophila; and this promoted bacterial resistance was significantly reduced by the co-injection of anti-MBL antibody with rMBL but not by the injection of anti-actin antibody with rMBL. These suggest that the lectin pathway may be already functional in the early embryos in zebrafish before their immune system is fully matured, protecting the developing embryos from microbial infection. This work provides a new angle to understand the immune role of the lectin pathway in early development of animals.

  1. The in vivo synthesis and accumulation of lectin in developing seeds of black gram (Vigna mungo L. Hepper).

    Science.gov (United States)

    Suseelan, K N; Mitra, R; Bhatia, C R; Gopalakrishna, T

    2004-01-01

    Black gram (Vigna mungo L. Hepper) seed contains two D-galactose-specific lectin species, BGL-I and BGL-II, identified on the basis of elution from ion exchange column and immunochemical cross-reactivity. BGL-I consisted of two monomeric lectins, BGL-I-1 and BGL-1-2, of relative molecular weights 94 and 89 kDa, respectively. BGL-II is another monomeric lectin with a molecular weight of 83 kDa. The in vivo synthesis studies using pulse-chase experiment showed that BGL-II lectin was synthesized as early as 14 days after flowering (DAF). The 94-kDa BGL-I-1 lectin was synthesized around 17 DAF. There was no cotranslational or posttranslational modification of the lectin proteins. The amount of lectin in developing seeds was determined by radial immunodiffusion assay technique. The maximum amount of lectin per seed was found at 28 DAF.

  2. Purification and primary structure of a mannose/glucose-binding lectin from Parkia biglobosa Jacq. seeds with antinociceptive and anti-inflammatory properties.

    Science.gov (United States)

    Silva, Helton C; Bari, Alfa U; Rocha, Bruno Anderson M; Nascimento, Kyria S; Ponte, Edson L; Pires, Alana F; Delatorre, Plínio; Teixeira, Edson H; Debray, Henri; Assreuy, Ana Maria S; Nagano, Celso S; Cavada, Benildo S

    2013-10-01

    Parkia biglobosa (subfamily Mimosoideae), a typical tree from African savannas, possess a seed lectin that was purified by combination of ammonium sulfate precipitation and affinity chromatography on a Sephadex G-100 column. The P. biglobosa lectin (PBL) strongly agglutinated rabbit erythrocytes, an effect that was inhibited by d-mannose and d-glucose-derived sugars, especially α-methyl-d-mannopyranoside and N-acetyl-d-glucosamine. The hemagglutinating activity of PBL was maintained after incubation at a wide range of temperature and pH and also was independent of divalent cations. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, PBL exhibited an electrophoretic profile consisting of a single band with apparent molecular mass of 45 kDa. An analysis using electrospray ionization-mass spectrometry indicated that purified lectin possesses a molecular average mass of 47 562 ± 4 Da, and the analysis by gel filtration showed that PBL is a dimer in solution. The complete amino acid sequence of PBL, as determined using tandem mass spectrometry, consists of 443 amino acid residues. PBL is composed of a single non-glycosylated polypeptide chain of three tandemly arranged jacalin-related domains. Sequence heterogeneity was found in six positions, indicating that the PBL preparations contain highly homologous isolectins. PBL showed important antinociceptive activity associated to the inhibition of inflammatory process.

  3. The Macrophage Galactose-Type Lectin-1 (MGL1 Recognizes Taenia crassiceps Antigens, Triggers Intracellular Signaling, and Is Critical for Resistance to This Infection

    Directory of Open Access Journals (Sweden)

    Daniel Montero-Barrera

    2015-01-01

    Full Text Available C-type lectins are multifunctional sugar-binding molecules expressed on dendritic cells (DCs and macrophages that internalize antigens for processing and presentation. Macrophage galactose-type lectin 1 (MGL1 recognizes glycoconjugates expressing Lewis X structures which contain galactose residues, and it is selectively expressed on immature DCs and macrophages. Helminth parasites contain large amounts of glycosylated components, which play a role in the immune regulation induced by such infections. Macrophages from MGL1−/− mice showed less binding ability toward parasite antigens than their wild-type (WT counterparts. Exposure of WT macrophages to T. crassiceps antigens triggered tyrosine phosphorylation signaling activity, which was diminished in MGL1−/− macrophages. Following T. crassiceps infection, MGL1−/− mice failed to produce significant levels of inflammatory cytokines early in the infection compared to WT mice. In contrast, MGL1−/− mice developed a Th2-dominant immune response that was associated with significantly higher parasite loads, whereas WT mice were resistant. Flow cytometry and RT-PCR analyses showed overexpression of the mannose receptors, IL-4Rα, PDL2, arginase-1, Ym1, and RELM-α on MGL1−/− macrophages. These studies indicate that MGL1 is involved in T. crassiceps recognition and subsequent innate immune activation and resistance.

  4. The macrophage galactose-type lectin-1 (MGL1) recognizes Taenia crassiceps antigens, triggers intracellular signaling, and is critical for resistance to this infection.

    Science.gov (United States)

    Montero-Barrera, Daniel; Valderrama-Carvajal, Héctor; Terrazas, César A; Rojas-Hernández, Saúl; Ledesma-Soto, Yadira; Vera-Arias, Laura; Carrasco-Yépez, Maricela; Gómez-García, Lorena; Martínez-Saucedo, Diana; Becerra-Díaz, Mireya; Terrazas, Luis I

    2015-01-01

    C-type lectins are multifunctional sugar-binding molecules expressed on dendritic cells (DCs) and macrophages that internalize antigens for processing and presentation. Macrophage galactose-type lectin 1 (MGL1) recognizes glycoconjugates expressing Lewis X structures which contain galactose residues, and it is selectively expressed on immature DCs and macrophages. Helminth parasites contain large amounts of glycosylated components, which play a role in the immune regulation induced by such infections. Macrophages from MGL1(-/-) mice showed less binding ability toward parasite antigens than their wild-type (WT) counterparts. Exposure of WT macrophages to T. crassiceps antigens triggered tyrosine phosphorylation signaling activity, which was diminished in MGL1(-/-) macrophages. Following T. crassiceps infection, MGL1(-/-) mice failed to produce significant levels of inflammatory cytokines early in the infection compared to WT mice. In contrast, MGL1(-/-) mice developed a Th2-dominant immune response that was associated with significantly higher parasite loads, whereas WT mice were resistant. Flow cytometry and RT-PCR analyses showed overexpression of the mannose receptors, IL-4Rα, PDL2, arginase-1, Ym1, and RELM-α on MGL1(-/-) macrophages. These studies indicate that MGL1 is involved in T. crassiceps recognition and subsequent innate immune activation and resistance.

  5. Different Origins or Different Evolutions? Decoding the Spectral Diversity Among C-type Asteroids

    Science.gov (United States)

    Vernazza, P.; Castillo-Rogez, J.; Beck, P.; Emery, J.; Brunetto, R.; Delbo, M.; Marsset, M.; Marchis, F.; Groussin, O.; Zanda, B.; Lamy, P.; Jorda, L.; Mousis, O.; Delsanti, A.; Djouadi, Z.; Dionnet, Z.; Borondics, F.; Carry, B.

    2017-02-01

    Anhydrous pyroxene-rich interplanetary dust particles (IDPs) have been proposed as surface analogs for about two-thirds of all C-complex asteroids. However, this suggestion appears to be inconsistent with the presence of hydrated silicates on the surfaces of some of these asteroids, including Ceres. Here, we report the presence of enstatite (pyroxene) on the surface of two C-type asteroids (Ceres and Eugenia) based on their spectral properties in the mid-infrared range. The presence of this component is particularly unexpected in the case of Ceres, because most thermal evolution models predict a surface consisting of hydrated compounds only. The most plausible scenario is that Ceres’ surface has been partially contaminated by exogenous enstatite-rich material, possibly coming from the Beagle asteroid family. This scenario questions a similar origin for Ceres and the remaining C-types, and it possibly supports recent results obtained by the Dawn mission (NASA) that Ceres may have formed in the very outer solar system. Concerning the smaller D ∼ 200 km C-types such as Eugenia, both their derived surface composition (enstatite and amorphous silicates) and low density (ice), and that a significant volume fraction of these bodies has remained unaffected by hydrothermal activity likely implying a late accretion. In addition, their current heliocentric distance may best explain the presence or absence of water ice at their surfaces. Finally, we raise the possibility that CI chondrites, Tagish-Lake-like material, or hydrated IDPs may be representative samples of the cores of these bodies.

  6. U(VI) reduction by diverse outer surface c-type cytochromes of Geobacter sulfurreducens.

    Science.gov (United States)

    Orellana, Roberto; Leavitt, Janet J; Comolli, Luis R; Csencsits, Roseann; Janot, Noemie; Flanagan, Kelly A; Gray, Arianna S; Leang, Ching; Izallalen, Mounir; Mester, Tünde; Lovley, Derek R

    2013-10-01

    Early studies with Geobacter sulfurreducens suggested that outer-surface c-type cytochromes might play a role in U(VI) reduction, but it has recently been suggested that there is substantial U(VI) reduction at the surface of the electrically conductive pili known as microbial nanowires. This phenomenon was further investigated. A strain of G. sulfurreducens, known as Aro-5, which produces pili with substantially reduced conductivity reduced U(VI) nearly as well as the wild type, as did a strain in which the gene for PilA, the structural pilin protein, was deleted. In order to reduce rates of U(VI) reduction to levels less than 20% of the wild-type rates, it was necessary to delete the genes for the five most abundant outer surface c-type cytochromes of G. sulfurreducens. X-ray absorption near-edge structure spectroscopy demonstrated that whereas 83% ± 10% of the uranium associated with wild-type cells correspond to U(IV) after 4 h of incubation, with the quintuple mutant, 89% ± 10% of uranium was U(VI). Transmission electron microscopy and X-ray energy dispersion spectroscopy revealed that wild-type cells did not precipitate uranium along pili as previously reported, but U(IV) was precipitated at the outer cell surface. These findings are consistent with those of previous studies, which have suggested that G. sulfurreducens requires outer-surface c-type cytochromes but not pili for the reduction of soluble extracellular electron acceptors.

  7. Glycodendrimersomes from Sequence-Defined Janus Glycodendrimers Reveal High Activity and Sensor Capacity for the Agglutination by Natural Variants of Human Lectins.

    Science.gov (United States)

    Zhang, Shaodong; Xiao, Qi; Sherman, Samuel E; Muncan, Adam; Ramos Vicente, Andrea D M; Wang, Zhichun; Hammer, Daniel A; Williams, Dewight; Chen, Yingchao; Pochan, Darrin J; Vértesy, Sabine; André, Sabine; Klein, Michael L; Gabius, Hans-Joachim; Percec, Virgil

    2015-10-21

    A library of eight amphiphilic Janus glycodendrimers (Janus-GDs) presenting D-lactose (Lac) and a combination of Lac with up to eight methoxytriethoxy (3EO) units in a sequence-defined arrangement was synthesized via an iterative modular methodology. The length of the linker between Lac and the hydrophobic part of the Janus-GDs was also varied. Self-assembly by injection from THF solution into phosphate-buffered saline led to unilamellar, monodisperse glycodendrimersomes (GDSs) with dimensions predicted by Janus-GD concentration. These GDSs provided a toolbox to measure bioactivity profiles in agglutination assays with sugar-binding proteins (lectins). Three naturally occurring forms of the human adhesion/growth-regulatory lectin galectin-8, Gal-8S and Gal-8L, which differ by the length of linker connecting their two active domains, and a single amino acid mutant (F19Y), were used as probes to study activity and sensor capacity. Unpredictably, the sequence of Lac on the Janus-GDs was demonstrated to determine bioactivity, with the highest level revealed for a Janus-GD with six 3EO groups and one Lac. A further increase in Lac density was invariably accompanied by a substantial decrease in agglutination, whereas a decrease in Lac density resulted in similar or lower bioactivity and sensor capacity. Both changes in topology of Lac presentation of the GDSs and seemingly subtle alterations in protein structure resulted in different levels of bioactivity, demonstrating the presence of regulation on both GDS surface and lectin. These results illustrate the applicability of Janus-GDs to dissect structure-activity relationships between programmable cell surface models and human lectins in a highly sensitive and physiologically relevant manner.

  8. Preparation and biological properties of a melibiose binding lectin from Bauhinia variegata seeds.

    Science.gov (United States)

    Lin, Peng; Ng, Tzi Bun

    2008-11-26

    A dimeric 64-kDa melibiose-binding lectin was isolated from the seeds of Bauhinia variegata. The isolation procedure comprised affinity chromatography on Affi-gel blue gel, ion exchange chromatography on Mono Q, and gel filtration on Superdex 75. The lectin was adsorbed on the first two chromatographic media. Its hemagglutinating activity was stable after 30-min exposure to temperatures up to 70 degrees C. Since lectins may demonstrate biological activities such as antiproliferative, immunomodulatory, antifungal, antiviral, and HIV-1 reverse transcriptase inhibitory activities, the isolated lectin was tested for these activities. It was found that the lectin inhibited proliferation in hepatoma HepG2 cells and breast cancer MCF7 cells with an IC(50) of 1.4 microM and 0.18 microM, respectively. HIV-1 reverse transcriptase activity was inhibited with an IC(50) of 1.02 microM. The lectin and concanavalin A (Con A) evoked maximal mitogenic response from mouse splenocytes at similar concentrations, but the maximal response to B. variegata lectin was only 1/5 of that induced by Con A in magnitude. B. variegata lectin was devoid of antifungal activity.

  9. Serine protease immunohistochemistry and lectin histochemistry in the small intestine of weaned and unweaned pigs

    DEFF Research Database (Denmark)

    Brown, P J; Poulsen, Steen Seier; Wells, M

    1991-01-01

    The distribution of goblet cells containing serine protease and of those binding the lectin Ulex europaeus agglutinin-1 (UEA-1) in the pig small intestine is altered during the period after weaning. Goblet cells exhibiting binding of other lectins were not altered. These alterations and other...

  10. Antinociceptive activity of lectins from Diocleinae seeds on acetic acid-induced writhing test in mice.

    Science.gov (United States)

    Holanda, Fernanda R; Coelho-de-Sousa, Andrelina N; Assreuy, Ana M S; Leal-Cardoso, José Henrique; Pires, Alana F; do Nascimento, Kyria S; Teixeira, Cícero S; Cavada, Benildo S; Santos, Cláudia F

    2009-01-01

    Diocleinae lectins administered per oral route in mice inhibited the abdominal constrictions induced by acetic acid. The percentage of the lectins antinociception varied from 61% for Canavalia grandiflora (ConGf) to 20% for Dioclea violacea. ConGf inhibited contortions at all doses tested but not in a dose-dependent manner, involving carbohydrate recognition.

  11. Mannose-binding lectin variant alleles and the risk of arterial thrombosis in systemic lupus erythematosus

    DEFF Research Database (Denmark)

    Øhlenschlaeger, Tommy; Garred, Peter; Madsen, Hans O

    2004-01-01

    Cardiovascular disease is an important complication in patients with systemic lupus erythematosus (SLE). Variant alleles of the mannose-binding lectin gene are associated with SLE as well as with severe atherosclerosis. We determined whether mannose-binding lectin variant alleles were associated...

  12. Mannose-binding lectin polymorphisms and susceptibility to infection in systemic lupus erythematosus

    DEFF Research Database (Denmark)

    Garred, P; Madsen, H O; Halberg, P

    1999-01-01

    To determine whether variant alleles in the coding portion of the mannose-binding lectin (MBL) gene are associated with increased susceptibility to systemic lupus erythematosus (SLE) and concomitant infections.......To determine whether variant alleles in the coding portion of the mannose-binding lectin (MBL) gene are associated with increased susceptibility to systemic lupus erythematosus (SLE) and concomitant infections....

  13. Carbohydrate Nanotechnology: Hierarchical Assemblies and Information Processing from Oligosaccharide-Synthetic Lectin Host-Guest

    Science.gov (United States)

    2014-09-17

    controlled grafted-from brush polymerization strategy, and the resulting glycopolymers are orders-of-magnitude more sensitive towards lectins compared to...was made towards all research goals. We have developed a new, mannose-specific synthetic lectin scaffold that achieves specificity through...and thereby initiate photochemical brush polymerizations . This reaction methodology was used to create carbohydrate-containing brush polymers with

  14. Purification and Characterization of a Lectin from Phaseolus vulgaris cv. (Anasazi Beans

    Directory of Open Access Journals (Sweden)

    Arishya Sharma

    2009-01-01

    Full Text Available A lectin has been isolated from seeds of the Phaseolus vulgaris cv. “Anasazi beans” using a procedure that involved affinity chromatography on Affi-gel blue gel, fast protein liquid chromatography (FPLC-ion exchange chromatography on Mono S, and FPLC-gel filtration on Superdex 200. The lectin was comprised of two 30-kDa subunits with substantial N-terminal sequence similarity to other Phaseolus lectins. The hemagglutinating activity of the lectin was stable within the pH range of 1–14 and the temperature range of 0–80∘C. The lectin potently suppressed proliferation of MCF-7 (breast cancer cells with an IC50 of 1.3 μM, and inhibited the activity of HIV-1 reverse transcriptase with an IC50 of 7.6 μM. The lectin evoked a mitogenic response from murine splenocytes as evidenced by an increase in [3H-methyl]-thymidine incorporation. The lectin had no antifungal activity. It did not stimulate nitric oxide production by murine peritoneal macrophages. Chemical modification results indicated that tryptophan was crucial for the hemagglutinating activity of the lectin.

  15. Biosynthesis, primary structure and molecular cloning of snowdrop (Galanthus nivalis L.) lectin.

    Science.gov (United States)

    Van Damme, E J; Kaku, H; Perini, F; Goldstein, I J; Peeters, B; Yagi, F; Decock, B; Peumans, W J

    1991-11-15

    Poly(A)-rich RNA isolated from ripening ovaries of snowdrop (Galanthus nivalis L.) yielded a single 17-kDa lectin polypeptide upon translation in a wheat-germ cell-free system. This lectin was purified by affinity chromatography. Translation of the same RNA in Xenopus leavis oocytes revealed a lectin polypeptide which was about 2 kDa smaller than the in vitro synthesized precursor, suggesting that the oocyte system had removed a 2-kDa signal peptide. A second post-translational processing step was likely to be involved since both the in vivo precursor and the Xenopus translation products were about 2 kDa larger than the mature lectin polypeptide. This hypothesis was confirmed by the structural analysis of the amino acid sequence of the mature protein and the cloned mRNA. Edman degradation and carboxypeptidase Y digestion of the mature protein, and structural analysis of the peptides obtained after chemical cleavage and modification, allowed determination of the complete 105 amino acid sequence of the snowdrop lectin polypeptide. Comparison of this sequence with the deduced amino acid sequence of a lectin cDNA clone revealed that besides the mature lectin polypeptide, the lectin mRNA also encoded a 23 amino acid signal-sequence and a C-terminal extension of 29 amino acids, which confirms the results from in vitro translation experiments.

  16. Effect of granule size on the properties of lotus rhizome C-type starch.

    Science.gov (United States)

    Lin, Lingshang; Huang, Jun; Zhao, Lingxiao; Wang, Juan; Wang, Zhifeng; Wei, Cunxu

    2015-12-10

    Lotus rhizome C-type starch was separated into different size fractions. Starch morphologies changed from irregular to elongated, ellipsoid, oval, and spherical with decreasing granule size. The small- and very-small-sized fractions had a centric hilum, and the other size fractions had an eccentric hilum. The different size fractions all showed C-type crystallinity, pseudoplasticity and shear-thinning rheological properties. The range of amylose content was 25.6 to 26.6%, that of relative crystallinity was 23.9 to 25.8%, that of swelling power was 29.0 to 31.4 g/g, and that of gelatinization enthalpy was 12.4 to 14.2J/g. The very-small-sized fraction had a significantly lower short-range ordered degree and flow behavior index and higher scattering peak intensity, water solubility, gelatinization peak temperature, gelatinization conclusion temperature, consistency coefficient, hydrolysis degrees, and digestion rate than the large-sized fraction. Granule size significantly positively influenced short-range ordered structure and swelling power and negatively influenced scattering peak intensity, water solubility, hydrolysis and digestion of starch (p<0.01).

  17. Crystalline and structural properties of acid-modified lotus rhizome C-type starch.

    Science.gov (United States)

    Cai, Jinwen; Cai, Canhui; Man, Jianmin; Yang, Yang; Zhang, Fengmin; Wei, Cunxu

    2014-02-15

    The crystalline and structural properties of acid-modified C-type starch from lotus rhizomes were investigated using a combination of techniques. The degradation of granule during hydrolysis began from the end distant from the hilum and then propagated into the center of granule, accompanied by loss of birefringence. The crystallinity changed from C-type to A-type via CA-type during hydrolysis. At the early stage of hydrolysis, the amylose content substantially reduced, the peak and conclusion gelatinization temperatures increased, and the enthalpy decreased. During hydrolysis, the double helix content gradually increased and the amorphous component decreased, the lamellar peak intensity firstly increased and then decreased accompanied by hydrolysis of amorphous and crystalline regions. This study elucidated that B-type allomorph was mainly arranged in the distal region of eccentric hilum, A-type allomorph was mainly located in the periphery of hilum end, and the center of granule was a mixed distribution of A- and B-type allomorphs.

  18. A hypothesis on the origin of C-type asteroids and carbonaceous chondrites

    CERN Document Server

    Busarev, V V

    2012-01-01

    A hypothesis based on observational and theoretical results on the origin of C-type asteroids and carbonaceous chondrites is proposed. Asteroids of C-type and close BGF-types could form from hydrated silicate-organic matter accumulated in the cores of water-differentiated (due to 26Al and other short-lived isotopes decay) bodies existed in the growth zones of Jupiter. Gravitational scattering of such bodies by Jupiter at its final stage of formation to the main asteroid belt might have led to fragmentation and re-accretion of their primitive materials on the surfaces of many asteroids and/or asteroid parent bodies. The hypothesis makes clear a row of long-standing puzzling facts, the main of which are as follows. The low-albedo and carbonaceous-chondritic surface properties of (1) Ceres contradict to its probable differentiated structure and icy crust (e. g., Thomas et al., 2005, Nature 437: 224-226; Castillo-Rogez et al., 2010, Icarus 205, 443-459), but it could be explained by the process of primitive matte...

  19. Effects of Glutamic Acid on C-type Inactivation of Kvl.4△N Channel

    Institute of Scientific and Technical Information of China (English)

    Cheng Ye; Xiaoyan Li; Zhouwu Shu; Xuejun Jiang

    2008-01-01

    Objectives Acidosis has an inhibitory effect on the inactivation of Kvl.4 AN channel through the position H508.So in order to show the effects of glutamic acid on the mutant Kv 1.4 channel that lacks N-type inactivation(Kvl.4A2-146),we studied in the expression system of the Xenopus oocytes.Methods The two-electrode voltage-clamp technique(TEV)was used to record the currents.Results Acidosis increased fKvl.4 △2-146 C-type inactivation.After application of glutamic acid(1 mmol/L) to Kvl.4 △2-146 increased C-type inactivation further,changed inactivation time constants from (2.02±0.39s)to(1.71±0.23 s)(P<0.05)at +50my,and shifted the steadystate inactivation curves of Kvl.4 △N to positive potential,which was from(-44.30±0.59 mV) to(-39.88±0.29 mV)(P<0.05 ).and slowed the rate of recovery from inactivation,which was from(1.64±0.19s) to (1.91±0.23 s)(P<0.05).Conclusions Together,these results suggest that 1 mmol/L glutamic acid accelerates the Ctype inactivation of Kvl.4 AN in pH 6.8.

  20. Isolation and characterization of a c-type lysozyme from the nurse shark.

    Science.gov (United States)

    Hinds Vaughan, Nichole; Smith, Sylvia L

    2013-12-01

    Lysozyme is a ubiquitous antibacterial enzyme that occurs in numerous invertebrate and vertebrate species. Three forms have been described c-type, g-type and i-type which differ in primary structure. Shark lysozyme has not been characterized; here we report on the isolation and characterization of lysozyme from unstimulated shark (Ginglymostoma cirratum) leukocytes and provide amino acid sequence data across the highly conserved active site of the molecule identifying it to be a c-type lysozyme. A leukocyte lysate was applied either (a) to the first of two sequential DE-52 cellulose columns or alternatively, (b) to a DEAE-Sepharose column. Lysozyme activity in lysate and active fractions was identified by zones of lysis of Micrococcus lysodeikticus cell walls on lysoplates and zones of growth inhibition in agar diffusion assays using Planococcus citreus as the target organism. SDS-PAGE analysis revealed a 14 kDa protein which was identified as lysozyme by mass spectroscopic analysis of peptides, reactivity against anti-HEWL antibodies on a Western blot, hydrolysis of M. lysodeikticus cell walls, and inhibition of growth of P. citreus on AU-gel blots in which the area of growth inhibition correlated to a 14 kDa protein.

  1. Azospirillum lectin – induced changes in the content of nitric oxide in wheat seedling roots

    Directory of Open Access Journals (Sweden)

    Alen’kina S.A.

    2010-11-01

    Full Text Available The lectin of Azospirillum brasilense Sp7 at 40 μg ml-1 elicited two peaks of induction of nitric oxide synthesis in the roots of wheat seedlings after 3 and 26 h of coincubation. The lectin of A. brasilense Sp7.2.3, a mutant defective in lectin activity, produced the same effect, but the activation of nitric oxide synthesis in the roots was less in the case of 26-h incubation. Exposure to the lectins for 3 h increased citrulline synthesis in the plant cell to the same extent. This finding indicated that the Azospirillum lectins activate nitric oxide production through the NO signal system of plants, thereby acting as inducers of adaptation processes in the roots of wheat seedlings.

  2. [Lectin histochemistry of the Bufo marinus L. toad tongue].

    Science.gov (United States)

    González Elorriaga, M; Jaloveckas, D; Salazar de Candelle, M

    1995-01-01

    Lectin histochemistry at light microscope level was used in the tongue of the cane toad Bufo marinus to determine the distribution of sugar residues in glycoconjugates (GCs) previously localized and characterized by conventional histochemical techniques. Five horseradish-peroxidase (HRP) labeled-lectins, namely Con A, PNA, SBA, UEA-1 and WGS were used. Additionally, neuraminidase (N) treated sections before the staining procedures were used in order to dilucidate the presence of terminal sialic acid (SA). Sugar residues in GCs of the taste organ (TO) associated mucous cells stained more intensely with WGA than with Con A and UEA-1. All the sensory cells reacted with Con A and WGA but one type of them were characteristically labeled by UEA-1. The glycocalix (gc) of the TOs resulted intensely stained with Con A and with WGA and UEA-1 before and after N treatment. The GCs in the mucous-supporting cells of dorsal mucosae filiform papillae and folds reacted intensely with WGA and weakly with Con A. The ciliated cells (cic) were intense and characteristically stained with UEA-1 and WGA and moderately with Con A. The gc reacted more intensely with WGA than with Con A. Dorsal mucosae glands secretory cells mucins were characteristically stained with PNA, SBA and WGA besides Con A, while glandular ciliated cells showed the same staining pattern as in the filiform papillae. In the ventral mucosa all epithelium cells resulted stained with WGA and Con A, while differentiated goblet cells only reacted as well with UEA-1 and PNA before and after neuraminidase treatment. Unexpectedly, ciliated ventral mucosae cells did not react with UEA-1 but only with WGA and Con A. The results have shown that lectin histochemistry is an interesting tool to characterize similarities and differences in the lingual GCs sugar residues composition and distribution, particularly those located in epithelial cells.

  3. Re-examining the proposed lectin properties of IL-2.

    Science.gov (United States)

    Papalia, Giuseppe A; Rini, James M

    2008-03-01

    Early work examining the interactions of IL-2 and the urinary glycoprotein uromodulin led to the suggestion that IL-2 was a lectin with specificity for high-mannose and mannan ligands. Subsequent studies have attributed various roles to these properties, some critical to the cell proliferative activity of IL-2. In an attempt to verify the reported interaction between IL-2 and mannose containing carbohydrate ligands we studied two biologically active forms of IL-2 using various techniques including affinity chromatography, equilibrium dialysis, and NMR methods. Despite previous reports we have not been able to demonstrate that IL-2 possesses the ability to bind carbohydrate.

  4. Immunologically related lectins from stems and roots of developing seedlings of Cucurbita ficifolia: purification and some properties of root and stem lectins

    Directory of Open Access Journals (Sweden)

    Irena Lorenc-Kubis

    2014-02-01

    Full Text Available Hemagglutinating activity has been found in acetate extracts from roots and stems of squash seedlings (Cucurbita ficifolia. The hemaglutinating activity changes during seeds germination and seedling development. Dot blot and Western blot techniques have shown that proteins from these vegetative tissues cross-reacted with antibodies raised against endogenous cotyledons lectin CLBa and Con A.Lectins were isolated from stems and roots of 6-day old seedlings by precipitation with ethanol, affinity chromatography on Con A-Sepharose, gel filtration on Bio-gel P100 and separated by electrophoresis on polyacrylamide gel. Three purified lectins (RLA1, RLA2, RLA3 were obtained from roots and four from stems (SLA1, SLA2, SLA3, SLA4. The purified lectins from roots and stems agglutinated all human red blood cells, but sheep erythrocytes were most sensitive to agglutination. The hemagglutination of the root lectins RLA2 and RLA3 was inhibited by a very low concentration of arabinose, while RLA1, of xylose and Ga1NAc. Arabinose and Xylose were also found to be the most effective inhibitors of all stem lectins.

  5. Complement activating soluble pattern recognition molecules with collagen-like regions, mannan-binding lectin, ficolins and associated proteins

    DEFF Research Database (Denmark)

    Thiel, Steffen

    2007-01-01

    Mannan-binding lectin (MBL), L-ficolin, M-ficolin and H-ficolin are all complement activating soluble pattern recognition molecules with recognition domains linked to collagen-like regions. All four may form complexes with four structurally related proteins, the three MBL-associated serine...... proteases (MASPs), MASP-1, MASP-2 and MASP-3, and a smaller MBL-associated protein (MAp19). The four recognition molecules recognize patterns of carbohydrate or acetyl-group containing ligands. After binding to the relevant targets all four are able to activate the complement system. We thus have a system...... where four different and/or overlapping patterns of microbial origin or patterns of altered-self may be recognized, but in all cases the signalling molecules, the MASPs, are shared. MASP-1 and MASP-3 are formed from one gene, MASP1/3, by alternative splicing generating two different mRNAs from a single...

  6. Importance of c-Type cytochromes for U(VI reduction by Geobacter sulfurreducens

    Directory of Open Access Journals (Sweden)

    Leang Ching

    2007-03-01

    Full Text Available Abstract Background In order to study the mechanism of U(VI reduction, the effect of deleting c-type cytochrome genes on the capacity of Geobacter sulfurreducens to reduce U(VI with acetate serving as the electron donor was investigated. Results The ability of several c-type cytochrome deficient mutants to reduce U(VI was lower than that of the wild type strain. Elimination of two confirmed outer membrane cytochromes and two putative outer membrane cytochromes significantly decreased (ca. 50–60% the ability of G. sulfurreducens to reduce U(VI. Involvement in U(VI reduction did not appear to be a general property of outer membrane cytochromes, as elimination of two other confirmed outer membrane cytochromes, OmcB and OmcC, had very little impact on U(VI reduction. Among the periplasmic cytochromes, only MacA, proposed to transfer electrons from the inner membrane to the periplasm, appeared to play a significant role in U(VI reduction. A subpopulation of both wild type and U(VI reduction-impaired cells, 24–30%, accumulated amorphous uranium in the periplasm. Comparison of uranium-accumulating cells demonstrated a similar amount of periplasmic uranium accumulation in U(VI reduction-impaired and wild type G. sulfurreducens. Assessment of the ability of the various suspensions to reduce Fe(III revealed no correlation between the impact of cytochrome deletion on U(VI reduction and reduction of Fe(III hydroxide and chelated Fe(III. Conclusion This study indicates that c-type cytochromes are involved in U(VI reduction by Geobacter sulfurreducens. The data provide new evidence for extracellular uranium reduction by G. sulfurreducens but do not rule out the possibility of periplasmic uranium reduction. Occurrence of U(VI reduction at the cell surface is supported by the significant impact of elimination of outer membrane cytochromes on U(VI reduction and the lack of correlation between periplasmic uranium accumulation and the capacity for uranium

  7. Gal/GalNAc specific multiple lectins in marine bivalve Anadara granosa.

    Science.gov (United States)

    Adhya, Mausumi; Singha, Biswajit

    2016-03-01

    Complete lectin mapping of molluscs with their diversified recognition pattern and possible role in lectin-carbohydrate interaction based immune response triggering need much attention. In this communication, Gal/GalNAc specific three lectins AGL-IA (Anadara granosa lectin-IA), AGL-IB (A. granosa lectin-IB) and AGL-IV (A. granosa lectin-IV) and a lectin having hemolytic activity AGL-III (A. granosa lectin-III) were purified from the plasma of A. granosa bivalve by a combination of gel filtration and affinity chromatography. AGL-IA and IB were oligomeric lectins whereas, AGL-III and IV were monomeric. The molecular weight of AGL-IA, IB, III and IV were 375, 260, 45 and 33 kDa respectively. AGL-IA and IV agglutinated both rabbit and pronase treated human erythrocytes, whereas AGL-IB agglutinated only rabbit erythrocytes. AGL-III was found to agglutinate rabbit erythrocytes, however, it caused hemolysis of pronase treated human erythrocytes. The activity of all four lectins was calcium dependent and maximum at a pH range 7-8. Apart from Gal/GalNAc specific, the four lectins showed substantial differences in their carbohydrate recognition pattern. Moreover, there was a difference in the carbohydrate specificity between AGL-III and other three lectins (AGL-IA, AGL-IB and AGL-IV) towards polyvalent glycotope. On the one hand, 'cluster glycoside effect' i.e., an enhancement of the activity of a multivalent ligand, was observed for carbohydrate specificities of AGL-IA, AGL-IB, AGL-IV. On the other hand, the effect of multivalent ligands on the carbohydrate specificity of AGL-III was opposite of cluster glycoside effect. The affinity of AGL-IA, AGL-IB and AGL-IV for ligands can be ranked as follows: glycoproteins > polysaccharide > oligosaccharides and monosaccharides. However, Gal related monosaccharides were the best inhibitors of AGL-III and the inhibitory activity decreased gradually in the following order: monosaccharide > disaccharide > polysaccharide. Thus, the

  8. Processing-independent analysis for pro-C-type natriuretic peptide

    DEFF Research Database (Denmark)

    Lippert, Solvej Kølvraa; Rehfeld, Jens F.; Gøtze, Jens Peter

    2010-01-01

    proCNP concentrations similar to non-vasectomized men (range 107-705 pmol/L, age 34-44 years). Taken together, our new proCNP assay shows that proCNP is abundantly present in human seminal plasma and that seminal proCNP is secreted from the prostate gland and/or the seminal vesicles.......C-type natriuretic peptide (CNP) is expressed in several human tissues. We designed a specific processing-independent assay for proCNP-derived products and quantitated the concentrations in human seminal plasma from normal and vasectomized men. Antibodies were raised against the N-terminus of human...... proCNP 11-27. Samples were incubated with trypsin prior to immunoassay, which allows for the measurement of "total" proCNP irrespective of the degree of post-translational processing. Seminal plasma from normal young men and vasectomized men were collected and quantitated; the molecular heterogeneity...

  9. Identification of a novel human rhinovirus C type by antibody capture VIDISCA-454.

    Science.gov (United States)

    Jazaeri Farsani, Seyed Mohammad; Oude Munnink, Bas B; Canuti, Marta; Deijs, Martin; Cotten, Matthew; Jebbink, Maarten F; Verhoeven, Joost; Kellam, Paul; Loens, Katherine; Goossens, Herman; Ieven, Margareta; van der Hoek, Lia

    2015-01-19

    Causative agents for more than 30 percent of respiratory infections remain unidentified, suggesting that unknown respiratory pathogens might be involved. In this study, antibody capture VIDISCA-454 (virus discovery cDNA-AFLP combined with Roche 454 high-throughput sequencing) resulted in the discovery of a novel type of rhinovirus C (RV-C). The virus has an RNA genome of at least 7054 nt and carries the characteristics of rhinovirus C species. The gene encoding viral protein 1, which is used for typing, has only 81% nucleotide sequence identity with the closest known RV-C type, and, therefore, the virus represents the first member of a novel type, named RV-C54.

  10. Outbreak of infection caused by Neisseria meningitidis group C type 2 in a nursery.

    Science.gov (United States)

    Sáez-Nieto, J A; Perucha, M; Casamayor, H; Marcen, J J; Llacer, A; Garcia-Barreno, B; Casal, J

    1984-01-01

    An outbreak of meningococcal infection which took place in a nursery in Rioja, Spain, is reported. Between November 1981 and February 1982, 11 patients had meningitis with or without septicaemia. Two died. Three meningococcal strains from the patients isolated were studied. All three were group C type 2 and were resistant to sulphadiazine (MIC 50 mg/l) but susceptible to penicillin, ampicillin, chloramphenicol, rifampicin and spiramycin. This outbreak took place during an epidemic in which serogroup B was the most prevalent in Spain. Two surveys before and after chemoprophylaxis were made to determine the carrier rate in the nursery population. The strain causing the outbreak was found in 2.5 and 4 per cent of persons respectively. Rifampicin was administered to all carriers after the first survey and to carriers of the virulent strain after the second survey. The remaining children were given polysaccharide C vaccine. No more cases arose after this last prophylactic measure.

  11. Intracellular mannose binding lectin mediates subcellular trafficking of HIV-1 gp120 in neurons.

    Science.gov (United States)

    Teodorof, C; Divakar, S; Soontornniyomkij, B; Achim, C L; Kaul, M; Singh, K K

    2014-09-01

    Human immunodeficiency virus-1 (HIV-1) enters the brain early during infection and leads to severe neuronal damage and central nervous system impairment. HIV-1 envelope glycoprotein 120 (gp120), a neurotoxin, undergoes intracellular trafficking and transport across neurons; however mechanisms of gp120 trafficking in neurons are unclear. Our results show that mannose binding lectin (MBL) that binds to the N-linked mannose residues on gp120, participates in intravesicular packaging of gp120 in neuronal subcellular organelles and also in subcellular trafficking of these vesicles in neuronal cells. Perinuclear MBL:gp120 vesicular complexes were observed and MBL facilitated the subcellular trafficking of gp120 via the endoplasmic reticulum (ER) and Golgi vesicles. The functional carbohydrate recognition domain of MBL was required for perinuclear organization, distribution and subcellular trafficking of MBL:gp120 vesicular complexes. Nocodazole, an agent that depolymerizes the microtubule network, abolished the trafficking of MBL:gp120 vesicles, suggesting that these vesicular complexes were transported along the microtubule network. Live cell imaging confirmed the association of the MBL:gp120 complexes with dynamic subcellular vesicles that underwent trafficking in neuronal soma and along the neurites. Thus, our findings suggest that intracellular MBL mediates subcellular trafficking and transport of viral glycoproteins in a microtubule-dependent mechanism in the neurons.

  12. Collectin-11/MASP complex formation triggers activation of the lectin complement pathway--the fifth lectin pathway initiation complex

    DEFF Research Database (Denmark)

    Ma, Ying Jie; Skjoedt, Mikkel-Ole; Garred, Peter

    2013-01-01

    complement pathway regulator MAP-1. Furthermore, we found that complex formation between recombinant collectin-11 and recombinant MASP-2 on Candida albicans leads to deposition of C4b. Native collectin-11 in serum mediated complement activation and deposition of C4b and C3b, and formation of the terminal...... complement complex on C. albicans. Moreover, spiking collectin-11-depleted serum, which did not mediate complement activation, with recombinant collectin-11 restored the complement activation capability. These results define collectin-11 as the fifth recognition molecule in the lectin complement pathway...

  13. Carbohydrate specificity of lectin, purified from the fruiting bodies of Mycena pura /Fr./ Kumm. and its use in histochemical investigation

    Directory of Open Access Journals (Sweden)

    Ambarova N. O.

    2009-12-01

    Full Text Available Aim. The purpose of this investigation was to research carbohydrate specificity of a new lectin from fruiting body of Mycena pura and possibilities of its application in histochemical studies. Methods. The lectin has been purified by affinity chromatography on «îvomucine». The lectin carbohydrate specificity has been determined by a reaction of inhibiting haemagglutination by haptens. Histological materials were fixed in 4 % neutral formalin solution. Alkaline phosphatase was revealed in the cryostat unfixed microscopical sections. Results. The lectin yield from fresh fruit bodies of raw material was 9 mg/kg. Mol. mass of the lectin is 40 kDa. The lectin poorly interacted with D-glucose and D-mannose in contrast to lectins from Pisum sativum and Leucojum vernum. The peculiarity of this lectin is its strong interaction with alkaline phosphatase, the highest among twenty tested lectins. However, the receptors for Mycena lectin binding in mammalian tissues are not limited by this enzyme being presented also by glycoconjugates of another structure, as it was shown for fetus calf small intestine and kidney of rat. Conclusions. An important role in the lectin interaction with glycoproteins probably belongs to the disaccharide links of GlcNAcb(1-2Mana(1-6 or GlcNAcb(1- 2Mana(1-2, which not necessarily are terminal

  14. Anti-Neuroblastoma Properties of a Recombinant Sunflower Lectin

    Directory of Open Access Journals (Sweden)

    Marcela Pinedo

    2017-01-01

    Full Text Available According to their sugar recognition specificity, plant lectins are proposed as bioactive proteins with potential in cancer treatment and diagnosis. Helja is a mannose-specific jacalin-like lectin from sunflower which was shown to inhibit the growth of certain fungi. Here, we report its recombinant expression in a prokaryotic system and its activity in neurobalstoma cells. Helja coding sequence was fused to the pET-32 EK/LIC, the enterokinase/Ligation-independent cloning vector and a 35 kDa protein was obtained in Escherichia coli representing Helja coupled to thioredoxin (Trx. The identity of this protein was verified using anti-Helja antibodies. This chimera, named Trx-rHelja, was enriched in the soluble bacterial extracts and was purified using Ni+2-Sepharose and d-mannose-agarose chromatography. Trx-rHelja and the enterokinase-released recombinant Helja (rHelja both displayed toxicity on human SH-SY5Y neuroblastomas. rHelja decreased the viability of these tumor cells by 75% according to the tetrazolium reduction assay, and microscopic analyses revealed that the cell morphology was disturbed. Thus, the stellate cells of the monolayer became spheroids and were isolated. Our results indicate that rHelja is a promising tool for the development of diagnostic or therapeutic methods for neuroblastoma cells, the most common solid tumors in childhood.

  15. Lectin functionalized quantum dots for recognition of mammary tumors

    Science.gov (United States)

    Santos, Beate S.; de Farias, Patricia M. A.; de Menezes, Frederico D.; de C. Ferreira, Ricardo; Júnior, Severino A.; Figueiredo, Regina C. B. Q.; Beltrão, Eduardo I. C.

    2006-02-01

    In this study we use CdS/Cd(OH) II quantum dots functionalized with concanavalin-A (Con-A) lectin, specific to glucose/mannose residues, to investigate cell alterations regarding carbohydrate profile in human mammary tissues diagnosed as fibroadenoma (benign tumor). These particles were functionalized with glutaraldehyde and Con-A and incubated with tissue sections of normal and to Fibroadenoma, a benign type of mammary tumor. The tissue sections were deparafinized, hydrated in graded alcohol and treated with a solution of Evans Blue in order to avoid autofluorescence. The fluorescence intensity of QD-Con-A stained tissues showed different patterns, which reflect the carbohydrate expression of glucose/mannose in fibroadenoma when compared to the detection of the normal carbohydrate expression. The pattern of unspecific labeling of the tissues with glutaraldehyde functionalized CdS/Cd(OH) II quantum dots is compared to the targeting driven by the Con-A lectin. The preliminary findings reported here support the use of CdS/Cd(OH) II quantum dots as specific probes of cellular alterations and their use in diagnostics.

  16. Anti-Neuroblastoma Properties of a Recombinant Sunflower Lectin

    Science.gov (United States)

    Pinedo, Marcela; Genoula, Melanie; Silveyra, María Ximena; De Oliveira Carvalho, André; Regente, Mariana; Del Río, Marianela; Ribeiro Soares, Júlia; Moreira Gomes, Valdirene; De La Canal, Laura

    2017-01-01

    According to their sugar recognition specificity, plant lectins are proposed as bioactive proteins with potential in cancer treatment and diagnosis. Helja is a mannose-specific jacalin-like lectin from sunflower which was shown to inhibit the growth of certain fungi. Here, we report its recombinant expression in a prokaryotic system and its activity in neurobalstoma cells. Helja coding sequence was fused to the pET-32 EK/LIC, the enterokinase/Ligation-independent cloning vector and a 35 kDa protein was obtained in Escherichia coli representing Helja coupled to thioredoxin (Trx). The identity of this protein was verified using anti-Helja antibodies. This chimera, named Trx-rHelja, was enriched in the soluble bacterial extracts and was purified using Ni+2-Sepharose and d-mannose-agarose chromatography. Trx-rHelja and the enterokinase-released recombinant Helja (rHelja) both displayed toxicity on human SH-SY5Y neuroblastomas. rHelja decreased the viability of these tumor cells by 75% according to the tetrazolium reduction assay, and microscopic analyses revealed that the cell morphology was disturbed. Thus, the stellate cells of the monolayer became spheroids and were isolated. Our results indicate that rHelja is a promising tool for the development of diagnostic or therapeutic methods for neuroblastoma cells, the most common solid tumors in childhood. PMID:28075401

  17. Revised domain structure of ulvan lyase and characterization of the first ulvan binding domain

    Science.gov (United States)

    Melcher, Rebecca L. J.; Neumann, Marten; Fuenzalida Werner, Juan Pablo; Gröhn, Franziska; Moerschbacher, Bruno M.

    2017-01-01

    Biomass waste products from green algae have recently been given new life, as these polysaccharides have potential applications in industry, agriculture, and medicine. One such polysaccharide group called ulvans displays many different, potentially useful properties that arise from their structural versatility. Hence, performing structural analyses on ulvan is crucial for future applications. However, chemical reaction–based analysis methods cannot fully characterize ulvan and tend to alter its structure. Thus, better methods require well-characterized ulvan-degrading enzymes. Therefore, we analysed a previously sequenced ulvan lyase (GenebankTM reference number JN104480) and characterized its domains. We suggest that the enzyme consists of a shorter than previously described catalytic domain, a newly identified substrate binding domain, and a C-terminal type 9 secretion system signal peptide. By separately expressing the two domains in E. coli, we confirmed that the binding domain is ulvan specific, having higher affinity for ulvan than most lectins for their ligands (affinity constant: 105 M−1). To our knowledge, this is the first description of an ulvan-binding domain. Overall, identifying this new binding domain is one step towards engineering ulvan enzymes that can be used to characterize ulvan, e.g. through enzymatic/mass spectrometric fingerprinting analyses, and help unlock its full potential. PMID:28327560

  18. Jacalin domain in wheat jasmonate-regulated protein Ta-JA1 confers agglutinating activity and pathogen resistance.

    Science.gov (United States)

    Ma, Qing-Hu; Zhen, Wei-Bo; Liu, Yun-Chao

    2013-02-01

    Ta-JA1 is a jacalin-like lectin from wheat (Triticum aestivum) plants. To date, its homologs are only observed in the Gramineae family. Our previous experiments have demonstrated that Ta-JA1 contains a modular structure consisting of an N-terminal dirigent domain and a C-terminal jacalin-related lectin domain (JRL) and this protein exhibits a mannose-specific lectin activity. The over-expression of Ta-JA1 gene provides transgenic plants a broad-spectrum resistance to diseases. Here, we report the differential activities of the dirigent and JRL domains of Ta-JA1. In vitro assay showed that the recombinant JRL domain could effectively agglutinate rabbit erythrocytes and pathogen bacteria Pseudomonas syringe pv tabaci. These hemagglutination activities could be inhibited by mannose but not by galactose. In contrast, the recombinant dirigent domain did not show agglutination activity. Corresponding to these differentiations of activities, similar to full-length of Ta-JA1, the over-expression of JRL domain in transgenic plants also increased resistance to the infection of P. syringe. Unlike JRL, the over-expression of dirigent domain in transgenic plants led to alteration of the seedling sensitivity to salts. In addition, a d(N)/d(S) ratio analysis of Ta-JA1 and its related proteins showed that this protein family functionally limited to a few crop plants, such as maize, rice and wheat.

  19. LpMab-12 Established by CasMab Technology Specifically Detects Sialylated O-Glycan on Thr52 of Platelet Aggregation-Stimulating Domain of Human Podoplanin.

    Directory of Open Access Journals (Sweden)

    Yukinari Kato

    Full Text Available Podoplanin (PDPN, also known as Aggrus, possesses three tandem repeat of platelet aggregation-stimulating (PLAG domains in its N-terminus. Among the PLAG domains, sialylated O-glycan on Thr52 of PLAG3 is essential for the binding to C-type lectin-like receptor-2 (CLEC-2 and the platelet-aggregating activity of human PDPN (hPDPN. Although various anti-hPDPN monoclonal antibodies (mAbs have been generated, no specific mAb has been reported to target the epitope containing glycosylated Thr52. We recently established CasMab technology to develop mAbs against glycosylated membrane proteins. Herein, we report the development of a novel anti-glycopeptide mAb (GpMab, LpMab-12. LpMab-12 detected endogenous hPDPN by flow cytometry. Immunohistochemical analyses also showed that hPDPN-expressing lymphatic endothelial and cancer cells were clearly labeled by LpMab-12. The minimal epitope of LpMab-12 was identified as Asp49-Pro53 of hPDPN. Furthermore, LpMab-12 reacted with the synthetic glycopeptide of hPDPN, corresponding to 38-54 amino acids (hpp3854: 38-EGGVAMPGAEDDVVTPG-54, which carries α2-6 sialylated N-acetyl-D-galactosamine (GalNAc on Thr52. LpMab-12 did not recognize non-sialylated GalNAc-attached glycopeptide, indicating that sialylated GalNAc on Thr52 is necessary for the binding of LpMab-12 to hPDPN. Thus, LpMab-12 could serve as a new diagnostic tool for determining whether hPDPN possesses the sialylation on Thr52, a site-specific post-translational modification critical for the hPDPN association with CLEC-2.

  20. Lectin typing of Campylobacter jejuni using a novel quartz crystal microbalance technique

    Energy Technology Data Exchange (ETDEWEB)

    Yakovleva, Maria E., E-mail: maria.yakovleva@gmail.com [Department of Infectious Diseases and Medical Microbiology, Lund University, 223 62 Lund (Sweden); Moran, Anthony P. [Department of Microbiology, School of Natural Sciences, National University of Ireland, Galway (Ireland); Safina, Gulnara R. [Department of Analytical and Marine Chemistry, University of Gothenburg, 412 96 Gothenburg (Sweden); Wadstroem, Torkel [Department of Infectious Diseases and Medical Microbiology, Lund University, 223 62 Lund (Sweden); Danielsson, Bengt [Acromed Invest AB, Magistratsvaegen 10, 226 43 Lund (Sweden)

    2011-05-23

    Seven Campylobacter jejuni strains were characterised by a lectin typing assay. The typing system was based on a quartz crystal microbalance technique (QCM) with four commercially available lectins (wheat germ agglutinin, Maackia amurensis lectin, Lens culinaris agglutinin, and Concanavalin A), which were chosen for their differing carbohydrate specificities. Initially, the gold surfaces of the quartz crystals were modified with 11-mercaptoundecanoic acid followed by lectin immobilisation using a conventional amine-coupling technique. Bacterial cells were applied for lectin typing without preliminary treatment, and resonant frequency and dissipation responses were recorded. The adhesion of microorganisms on lectin surfaces was confirmed by atomic force microscopy. Scanning was performed in the tapping mode and the presence of bacteria on lectin-coated surfaces was successfully demonstrated. A significant difference in the dissipation response was observed for different C. jejuni strains which made it possible to use this parameter for discriminating between bacterial strains. In summary, the QCM technique proved a powerful tool for the recognition and discrimination of C. jejuni strains. The approach may also prove applicable to strain discrimination of other bacterial species, particularly pathogens.

  1. A novel L-fucose-binding lectin from Fenneropenaeus indicus induced cytotoxicity in breast cancer cells.

    Science.gov (United States)

    Chatterjee, Biji; Ghosh, Krishna; Yadav, Nitin; Kanade, Santosh R

    2017-01-01

    Lectins are omnipresent in almost all life forms, being the proteins which specifically bind to carbohydrate moieties on the cell surface; they have been explored for their anti-tumour activities. In this study, we purified a fucose specific-lectin (IFL) from Fenneropenaeus indicus haemolymph using fucose-affinity column and characterized for its haemagglutination activity, carbohydrate specificity, dependency on cations and cytotoxicity against cancer cells. The lectin showed non-specificity against human erythrocytes. It was a Ca(2+)-dependent lectin which remained stable over wide pH and temperature ranges. The lectin showed effective dose dependent cytotoxicity against different human cancer cell lines and induced apoptosis in MCF-7 cells as evidenced by DNA ladder assay and PARP cleavage in a dose dependent manner. Moreover, an increased p21 level corresponding to cyclin D downregulation in response to IFL treatment was observed which might work as probable factors to inhibit cell growth and induce apoptosis of MCF-7 cells. Therefore, we report a novel lectin from the prawn haemolymph with high specificity for L-fucose and antiproliferative towards human cancer cells. However, further establishment of the modus operandi of this lectin is required to enable its biotechnological applications.

  2. Synthesis of a selective inhibitor of a fucose binding bacterial lectin from Burkholderia ambifaria.

    Science.gov (United States)

    Richichi, Barbara; Imberty, Anne; Gillon, Emilie; Bosco, Rosa; Sutkeviciute, Ieva; Fieschi, Franck; Nativi, Cristina

    2013-06-28

    Burkholderia ambifaria is a bacterium member of the Burkholderia cepacia complex (BCC), a closely related group of Gram-negative bacteria responsible for "cepacia syndrome" in immunocompromised patients. B. ambifaria produces BambL, a fucose-binding lectin that displays fine specificity to human fucosylated epitopes. Here, we report the first example of a synthetic ligand able to selectively bind, in the micromolar range, the pathogen-lectin BambL. The synthetic routes for the preparation of the α conformationally constrained fucoside are described, focusing on a totally diastereoselective inverse electron demand [4 + 2] Diels-Alder reaction. Isothermal titration calorimetry (ITC) demonstrated that this compound binds to the pathogen-associated lectin BambL with an affinity comparable to that of natural fucose-containing oligosaccharides. No binding was observed by LecB, a fucose-binding lectin from Pseudomonas aeruginosa, and the differences in affinity between the two lectins could be rationalized by modeling. Furthermore, SPR analyses showed that this fucomimetic does not bind to the human fucose-binding lectin DC-SIGN, thus supporting the selective binding profile towards B. ambifaria lectin.

  3. Effective inhibition of melanosome transfer to keratinocytes by lectins and niacinamide is reversible.

    Science.gov (United States)

    Greatens, Amanda; Hakozaki, Tomohiro; Koshoffer, Amy; Epstein, Howard; Schwemberger, Sandy; Babcock, George; Bissett, Donald; Takiwaki, Hirotsugu; Arase, Seiji; Wickett, R Randall; Boissy, Raymond E

    2005-07-01

    Skin pigmentation results in part from the transfer of melanized melanosomes synthesized by melanocytes to neighboring keratinocytes. Plasma membrane lectins and their glycoconjugates expressed by these epidermal cells are critical molecules involved in this transfer process. In addition, the derivative of vitamin B(3), niacinamide, can inhibit melanosome transfer and induce skin lightening. We investigated the effects of these molecules on the viability of melanocytes and keratinocytes and on the reversibility of melanosome-transfer inhibition induced by these agents using an in vitro melanocyte-keratinocyte coculture model system. While lectins and neoglycoproteins could induce apoptosis in a dose-dependent manner to melanocytes or keratinocytes in monoculture, similar dosages of the lectins, as opposed to neoglycoproteins, did not induce apoptosis to either cell type when treated in coculture. The dosages of lectins and niacinamide not affecting cell viability produced an inhibitory effect on melanosome transfer, when used either alone or together in cocultures of melanocytes-keratinocytes. Cocultures treated with lectins or niacinamide resumed normal melanosome transfer in 3 days after removal of the inhibitor, while cocultures treated with a combination of lectins and niacinamide demonstrated a lag in this recovery. Subsequently, we assessed the effect of niacinamide on facial hyperpigmented spots using a vehicle-controlled, split-faced design human clinical trial. Topical application of niacinamide resulted in a dose-dependent and reversible reduction in hyperpigmented lesions. These results suggest that lectins and niacinamide at concentrations that do not affect cell viability are reversible inhibitors of melanosome transfer.

  4. Purification and Characterization of a Lectin from Green Split Peas (Pisum sativum).

    Science.gov (United States)

    Ng, Tzi Bun; Chan, Yau Sang; Ng, Charlene Cheuk Wing; Wong, Jack Ho

    2015-11-01

    Lectins have captured the attention of a large number of researchers on account of their various exploitable activities, including antitumor, immunomodulatory, antifungal, as well as HIV reverse transcriptase inhibitory activities. A mannose/glucose-specific lectin was isolated from green split peas (a variety of Pisum sativum) and characterized. The purification step involved anion-exchange chromatography on a DEAE-cellulose column, cation-exchange chromatography on an SP-Sepharose column, and gel filtration by fast protein liquid chromatography (FPLC) on Superdex 200. The purified lectin had a native molecular mass of around 50 kDa as determined by size exclusion chromatography. It appeared as a heterotetramer, composed of two distinct polypeptide bands with a molecular mass of 6 and 19 kDa, respectively, in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The N-terminal sequence of green split pea lectin shows some degree of homology compared to lectins from other legume species. Its hemagglutinating activity was inhibited by glucose, mannose, and sucrose, and attenuated at pH values higher than 12 or lower than 3. Hemagglutinating activity was preserved at temperatures lower than 80 °C. The lectin did not show antifungal activity toward fungi including Fusarium oxysporum, Botrytis cinerea, and Mycosphaerella arachidicola. Green split pea lectin showed a mitogenic effect toward murine splenocytes and could inhibit the activity of HIV-1 reverse transcriptase.

  5. Purification and partial characterization of a fructose-binding lectin from the leaves of Euphorbia helioscopia.

    Science.gov (United States)

    Rafiq, Shaista; Qadir, Sakeena; Wani, Ishfak Hussain; Ganie, Showkat Ahmad; Masood, Akbar; Hamid, Rabia

    2014-11-01

    A lectin was purified from leaves of Euphorbia helioscopia, by a combination of ion-exchange and gel filtration chromatography. On ion exchange using a DEAE- cellulose column in 0.2 M phosphate buffer, pH 7.2, the bound protein was eluted with a linear sodium chloride gradient of 0.1 M to 0.5 M. Further purification of the lectin was achieved by gel filtration on Sephadex G-100. Euphorbia helioscopia lectin (EHL) agglutinates only chick erythrocytes, showing no agglutination of all human blood group erythrocytes. The EHL induced hemagglutination is inhibited by fructose. The purified protein showed one band, both in non-denaturing PAGE and SDS-PAGE establishing the charge and size homogeneities of the lectin preparation. The molecular mass of the lectin as indicated by SDS-PAGE was approximately 31 kDa and that estimated from G-100 gel filtration chromatography was about 65 kDa establishing that the lectin is a homodimer. The lectin was stable within a temperature range of 0°C-40°C and exhibited a narrow range of pH stability, being optimally active at around pH 7. EHL also possesses antimicrobial activity and is an inhibitor of bacterial growth particularly Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli.

  6. Lectin Histochemical Study of Cell Surface Glycoconjugate in Gastric Carcinoma Using Helix Pomatia Agglutinin

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Arab

    2010-07-01

    Full Text Available "nAltered glycosylation of proteins in cancer cells is one of the main processes responsible for anaplasia, invasion and metastatic potential of neoplastic cells. Lectins are nonimmunogenetic compounds which specifically detect certain terminal sugars of glycoconjugates. The aim of the present study was to identify the N-acetylgalactosamine (GalNac containing glycoconjugates in cancer cells in all grades of gastric carcinoma. Paraffin blocks belong to 30 patients of gastric carcinoma (10 cases from each grade was collected from pathology file of Ali-Ebn-Abitaleb Hospital in Zahedan during 2005-2007. Prepared sections (5-7μm in thickness were stained by Alcian Blue, hematoxylin and eosin (H&E and helix pomatia agglutinin (HPA conjugated lectin. Lectin diluted up to 10μg/ml in PBS (0.1M, pH=6.8. Lectin reactivity was visualized by 0.03% diaminobenzidine (DAB solution. Sections were graded according to staining intensity to lectin (0-4+. Although there was some difference for lectin staining intensity between cancer cells in different grades of gastric carcinoma, statistical analysis showed that there was only a significant difference for cancer cells reactivity between histopathological grades of II and III. The pattern of reactivity to HPA lectin were also different from all histopathological grades. It seems that in cancer cells, the amount and distribution of GalNac containing glycoconjugate differ from neoplastic cells of different histopathological grades in gastric carcinoma.

  7. Lectin Histochemical Study of Cell Surface Glycoconjugate in Gastric Carcinoma Using Helix Pomatia Agglutinin

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Arab

    2010-08-01

    Full Text Available Altered glycosylation of proteins in cancer cells is one of the main processes responsible for anaplasia, invasion and metastatic potential of neoplastic cells. Lectins are nonimmunogenetic compounds which specifically detect certain terminal sugars of glycoconjugates. The aim of the present study was to identify the N-acetylgalactosamine (GalNac containing glycoconjugates in cancer cells in all grades of gastric carcinoma. Paraffin blocks belong to 30 patients of gastric carcinoma (10 cases from each grade was collected from pathology file of Ali-Ebn-Abitaleb Hospital in Zahedan during 2005-2007. Prepared sections (5-7μm in thickness were stained by Alcian Blue, hematoxylin and eosin (H&E and helix pomatia agglutinin (HPA conjugated lectin. Lectin diluted up to 10μg/ml in PBS (0.1M, pH=6.8. Lectin reactivity was visualized by 0.03% diaminobenzidine (DAB solution. Sections were graded according to staining intensity to lectin (0-4+. Although there was some difference for lectin staining intensity between cancer cells in different grades of gastric carcinoma, statistical analysis showed that there was only a significant difference for cancer cells reactivity between histopathological grades of II and III. The pattern of reactivity to HPA lectin were also different from all histopathological grades. It seems that in cancer cells, the amount and distribution of GalNac containing glycoconjugate differ from neoplastic cells of different histopathological grades in gastric carcinoma.

  8. Isolation and characterization of a new mannose-binding lectin gene from Taxus media

    Indian Academy of Sciences (India)

    Guoyin Kai; Lingxia Zhao; Jingui Zheng; Lei Zhang; Zhiqi Miao; Xiaofen Sun; Kexuan Tanga

    2004-12-01

    In this paper, we report the cloning and characterization of the first mannose-binding lectin gene from a gymnosperm plant species, Taxus media. The full-length cDNA of T. media agglutinin (TMA) consisted of 676 bp and contained a 432 bp open reading frame (ORF) encoding a 144 amino acid protein. Comparative analysis showed that TMA had high homology with many previously reported plant mannose-binding lectins and that tma encoded a precursor lectin with a 26-aa signal peptide. Molecular modelling revealed that TMA was a new mannose-binding lectin with three typical mannose-binding boxes like lectins from species of angiosperms. Tissue expression pattern analyses revealed that tma is expressed in a tissue-specific manner in leaves and stems, but not in fruits and roots. Phylogenetic tree analyses showed that TMA belonged to the structurally and evolutionarily closely related monocot mannose-binding lectin superfamily. This study provides useful information to understand the molecular evolution of plant lectins.

  9. Studies of hemolytical and antimicrobical action of Amanita virosa Secr. and Mycena pura /Fr./ Kumm. poisonous mushrooms lectins

    Directory of Open Access Journals (Sweden)

    Danileuchenko V. V.

    2010-02-01

    Full Text Available Aim. To study hemolytical and antimicrobical action of two new lectins, obtained from fruit bodies of poisonous basidial mushrooms of A. virosa Secr. and M. pura /Fr./ Kumm. Methods. Research on hemolytical action of lectins was conducted on the erythrocytes of human and animals. The experiments on osmotic protection of erythrocytes were performed in the presence of polyethylenglycols of different molecular mass (in a range from 400 to 4000 Da. Antimicrobical activity of lectins was studied by determination of area delay of growth of culture of different types of microorganisms on the Petri dish in an agaric media. Results. Both lectins hemolyse the erythrocytes of rabbit, human, rat and dog and do not hemolyse the erythrocytes of cow and ship in concentration of 1 mg/ml. The rabbit erythrocytes are most sensitive to hemolytical action of lectins, while hemolytic ability of A. virosa lectin is higher. Hemolysis was not observed in the presence of PEG of molecular mass over 1,350 Da. Action of lectins on 10 types of microorganisms was investigated. Lectins inhibited mainly growth of grammpositive microorganisms and protey. For most tested microorganisms antimicrobial action of Mycena lectin is stronger comparing with A. virosa lectin. Conclusions. Two new hemolytical lectins are found in the fruit bodies of mushrooms-basidiomycetes. The lectin formed ion-permeable pores in membrane of erythrocytes with the hydrodynamic diameter smaller than 2.3 nm and larger than 1.6 nm. These lectins displays also antimicrobial activity and by the sum of these features are similar to the cytolytic lectins of lower invertebrates.

  10. Arabidopsis Lectin Receptor Kinases LecRK-IX.1 and LecRK-IX.2 Are Functional Analogs in Regulating Phytophthora Resistance and Plant Cell Death.

    Science.gov (United States)

    Wang, Yan; Cordewener, Jan H G; America, Antoine H P; Shan, Weixing; Bouwmeester, Klaas; Govers, Francine

    2015-09-01

    L-type lectin receptor kinases (LecRK) are potential immune receptors. Here, we characterized two closely-related Arabidopsis LecRK, LecRK-IX.1 and LecRK-IX.2, of which T-DNA insertion mutants showed compromised resistance to Phytophthora brassicae and Phytophthora capsici, with double mutants showing additive susceptibility. Overexpression of LecRK-IX.1 or LecRK-IX.2 in Arabidopsis and transient expression in Nicotiana benthamiana increased Phytophthora resistance but also induced cell death. Phytophthora resistance required both the lectin domain and kinase activity, but for cell death, the lectin domain was not needed. Silencing of the two closely related mitogen-activated protein kinase genes NbSIPK and NbNTF4 in N. benthamiana completely abolished LecRK-IX.1-induced cell death but not Phytophthora resistance. Liquid chromatography-mass spectrometry analysis of protein complexes coimmunoprecipitated in planta with LecRK-IX.1 or LecRK-IX.2 as bait, resulted in the identification of the N. benthamiana ABC transporter NbPDR1 as a potential interactor of both LecRK. The closest homolog of NbPDR1 in Arabidopsis is ABCG40, and coimmunoprecipitation experiments showed that ABCG40 associates with LecRK-IX.1 and LecRK-IX.2 in planta. Similar to the LecRK mutants, ABCG40 mutants showed compromised Phytophthora resistance. This study shows that LecRK-IX.1 and LecRK-IX.2 are Phytophthora resistance components that function independent of each other and independent of the cell-death phenotype. They both interact with the same ABC transporter, suggesting that they exploit similar signal transduction pathways.

  11. High-Mannose Specific Lectin and Its Recombinants from a Carrageenophyta Kappaphycus alvarezii Represent a Potent Anti-HIV Activity Through High-Affinity Binding to the Viral Envelope Glycoprotein gp120.

    Science.gov (United States)

    Hirayama, Makoto; Shibata, Hiromi; Imamura, Koji; Sakaguchi, Takemasa; Hori, Kanji

    2016-04-01

    We previously reported that a high-mannose binding lectin KAA-2 from the red alga Kappaphycus alvarezii, which is an economically important species and widely cultivated as a source of carrageenans, had a potent anti-influenza virus activity. In this study, the full-length sequences of two KAA isoforms, KAA-1 and KAA-2, were elucidated by a combination of peptide mapping and cDNA cloning. They consisted of four internal tandem-repeated domains, which are conserved in high-mannose specific lectins from lower organisms, including a cyanobacterium Oscillatoria agardhii and a red alga Eucheuma serra. Using an Escherichia coli expression system, an active recombinant form of KAA-1 (His-tagged rKAA-1) was successfully generated in the yield of 115 mg per a litter of culture. In a detailed oligosaccharide binding analysis by a centrifugal ultrafiltration-HPLC method with 27 pyridylaminated oligosaccharides, His-tagged rKAA-1 and rKAA-1 specifically bound to high-mannose N-glycans with an exposed α1-3 mannose in the D2 arm as the native lectin did. Predicted from oligosaccharide-binding specificity, a surface plasmon resonance analysis revealed that the recombinants exhibit strong interaction with gp120, a heavily glycosylated envelope glycoprotein of HIV with high association constants (1.48-1.61 × 10(9) M(-1)). Native KAAs and the recombinants inhibited the HIV-1 entry at IC50s of low nanomolar levels (7.3-12.9 nM). Thus, the recombinant proteins would be useful as antiviral reagents targeting the viral surface glycoproteins with high-mannose N-glycans, and the cultivated alga K. alvarezii could also be a good source of not only carrageenans but also this functional lectin(s).

  12. Physicochemical properties and oxidative inactivation of soluble lectin from water buffalo (Bubalus bubalis) brain.

    Science.gov (United States)

    Rizvi, Sabika; Banu, Naheed

    2008-03-01

    Lectins are carbohydrate-binding proteins present in a wide variety of plants and animals, which serve various important physiological functions. A soluble beta-galactoside binding lectin has been isolated and purified to homogeneity from buffalo brain using ammonium sulphate precipitation (40-70%) and gel permeation chromatography on Sephadex G50-80 column. The molecular weight of buffalo brain lectin (BBL) as determined by SDS-PAGE under reducing and non-reducing conditions was 14.2 kDa, however, with gel filtration it was 28.5 kDa, revealing the dimeric form of protein. The neutral sugar content of the soluble lectin was estimated to be 3.3%. The BBL showed highest affinity for lactose and other sugar moieties in glycosidic form, suggesting it to be a beta-galactoside binding lectin. The association constant for lactose binding as evidenced by Scatchard analysis was 6.6 x 10(3) M(-1) showing two carbohydrate binding sites per lectin molecule. A total inhibition of lectin activity was observed by denaturants like guanidine HCl, thiourea and urea at 6 M concentration. The treatment of BBL with oxidizing agent destroyed its agglutination activity, abolished its fluorescence, and shifted its UV absorption maxima from 282 to 250 nm. The effect of H2O2 was greatly prevented by lactose indicating that BBL is more stable in the presence of its specific ligand. The purified lectin was investigated for its brain cell aggregation properties by testing its ability to agglutinate cells isolated from buffalo and goat brains. Rate of aggregation of buffalo brain cells by purified protein was more than the goat brain cells. The data from above study suggests that the isolated lectin may belong to the galectin-1 family but is glycosylated unlike those purified till date.

  13. Differential activity of a lectin from Solieria filiformis against human pathogenic bacteria

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    M.L. Holanda

    2005-12-01

    Full Text Available A lectin isolated from the red alga Solieria filiformis was evaluated for its effect on the growth of 8 gram-negative and 3 gram-positive bacteria cultivated in liquid medium (three independent experiments/bacterium. The lectin (500 µg/mL stimulated the growth of the gram-positive species Bacillus cereus and inhibited the growth of the gram-negative species Serratia marcescens, Salmonella typhi, Klebsiella pneumoniae, Enterobacter aerogenes, Proteus sp, and Pseudomonas aeruginosa at 1000 µg/mL but the lectin (10-1000 µg/mL had no effect on the growth of the gram-positive bacteria Staphylococcus aureus and B. subtilis, or on the gram-negative bacteria Escherichia coli and Salmonella typhimurium. The purified lectin significantly reduced the cell density of gram-negative bacteria, although no changes in growth phases (log, exponential and of decline were observed. It is possible that the interaction of S. filiformis lectin with the cell surface receptors of gram-negative bacteria promotes alterations in the flow of nutrients, which would explain the bacteriostatic effect. Growth stimulation of the gram-positive bacterium B. cereus was more marked in the presence of the lectin at a concentration of 1000 µg/mL. The stimulation of the growth of B. cereus was not observed when the lectin was previously incubated with mannan (125 µg/mL, its hapten. Thus, we suggest the involvement of the binding site of the lectin in this effect. The present study reports the first data on the inhibition and stimulation of pathogenic bacterial cells by marine alga lectins.

  14. Purification of a N-acetyl-D-galactosamine specific lectin from the orchid Laelia autumnalis.

    Science.gov (United States)

    Zenteno, R; Chávez, R; Portugal, D; Páez, A; Lascurain, R; Zenteno, E

    1995-10-01

    From the pseudobulbs of the orchid L. autumnalis a lectin was purified on immobilized porcine mucin with A + H blood group substance. This lectin is a dimeric glycoprotein of M(r) 12,000 with an Sw,20 of 2.2, showing haemagglutinating activity directed mainly to human A1 desialylated erythrocytes. The lectin possesses sugar specificity for N-acetyl-D-galactosamine and also shows high specificity for glycoproteins containing the T (galactose beta 1,3GA1NAc alpha 1,0 Ser/Thr) or the Tn antigen (GalNAc alpha 1,0 Ser/Thr).

  15. Application of lectin microarray to crude samples: differential glycan profiling of lec mutants.

    Science.gov (United States)

    Ebe, Youji; Kuno, Atsushi; Uchiyama, Noboru; Koseki-Kuno, Shiori; Yamada, Masao; Sato, Takashi; Narimatsu, Hisashi; Hirabayashi, Jun

    2006-03-01

    We recently developed a novel system for lectin microarray based on the evanescent-field fluorescence-detection principle, by which even weak lectin-oligosaccharide interactions are detectable without a washing procedure. For its practical application, cell glycan analysis was performed for Chinese hamster ovary (CHO) cells and their glycan profile was compared with those of their glycosylation-defective Lec mutants. Each of the cell surface extracts gave a significantly different profile from that of the parental CHO cells in a manner reflecting denoted biosynthetic features. Hence, the developed lectin microarray system is considered to be fully applicable for differential glycan profiling of crude samples.

  16. Urinary C-type natriuretic peptide: an emerging biomarker for heart failure and renal remodeling.

    Science.gov (United States)

    Zakeri, Rosita; Burnett, John C; Sangaralingham, S Jeson

    2015-03-30

    The public health and economic burden of heart failure (HF) is staggering and the need for relevant pathophysiologic and clinical biomarkers to advance the field and improve HF therapy remains high. Renal dysfunction is common among HF patients and is associated with increased HF hospitalization and mortality. It is widely recognized that mechanisms contributing to HF pathogenesis include a complex bidirectional interaction between the kidney and heart, encompassed by the term cardiorenal syndrome (CRS). Among a new wave of urinary biomarkers germane to CRS, C-type natriuretic peptide (CNP) has emerged as an innovative biomarker of renal structural and functional impairment in HF and chronic renal disease states. CNP is a hormone, synthesized in the kidney, and is an important regulator of cell proliferation and organ fibrosis. Hypoxia, cytokines and fibrotic growth factors, which are inherent to both cardiac and renal remodeling processes, are among the recognized stimuli for CNP production and release. In this review we aim to highlight current knowledge regarding the biology and pathophysiological correlates of urinary CNP, and its potential clinical utility as a diagnostic and prognostic biomarker in HF and renal disease states.

  17. SiO line emission from C-type shock waves : interstellar jets and outflows

    CERN Document Server

    Gusdorf, A; Flower, D R; Forets, G Pineau des

    2008-01-01

    We study the production of SiO in the gas phase of molecular outflows, through the sputtering of Si--bearing material in refractory grain cores, which are taken to be olivine; we calculate also the rotational line spectrum of the SiO. The sputtering is driven by neutral particle impact on charged grains, in steady--state C-type shock waves, at the speed of ambipolar diffusion. The emission of the SiO molecule is calculated by means of an LVG code. A grid of models has been generated. We compare our results with those of an earlier study (Schilke et al. 1997). Improvements in the treatment of the coupling between the charged grains and the neutral fluid lead to narrower shock waves and lower fractions of Si being released into the gas phase. More realistic assumptions concerning the initial fractional abundance of O2 lead to SiO formation being delayed, so that it occurs in the cool, dense postshock flow. Good agreement is obtained with recent observations of SiO line intensities in the L1157 and L1448 molecul...

  18. Detection of Sugar-Lectin Interactions by Multivalent Dendritic Sugar Functionalized Single-Walled Carbon Nanotubes

    CERN Document Server

    Vasu, K S; Bagul, R S; Jayaraman, N; Sood, A K; 10.1063/1.4739793

    2012-01-01

    We show that single walled carbon nanotubes (SWNT) decorated with sugar functionalized poly (propyl ether imine) (PETIM) dendrimer is a very sensitive platform to quantitatively detect carbohydrate recognizing proteins, namely, lectins. The changes in electrical conductivity of SWNT in field effect transistor device due to carbohydrate - protein interactions form the basis of present study. The mannose sugar attached PETIM dendrimers undergo charge - transfer interactions with the SWNT. The changes in the conductance of the dendritic sugar functionalized SWNT after addition of lectins in varying concentrations were found to follow the Langmuir type isotherm, giving the concanavalin A (Con A) - mannose affinity constant to be 8.5 x 106 M-1. The increase in the device conductance observed after adding 10 nM of Con A is same as after adding 20 \\muM of a non - specific lectin peanut agglutinin, showing the high specificity of the Con A - mannose interactions. The specificity of sugar-lectin interactions was chara...

  19. STUDY OF AZOSPIRILLUM LECTINS INFLUENCE ON HYDROGEN PEROXIDE PRODUCTION IN WHEAT-ROOTS

    Directory of Open Access Journals (Sweden)

    Alen’kina S.A.

    2009-12-01

    Full Text Available It was found that two cell-surface lectins isolated from the nitrogen-fixing soil bacterium Azospirillum brasilense Sp7 and from its mutant defective in lectin activity, A. brasilense Sp7.2.3 can stimulate rapid formation of hydrogen peroxide, associated with an increase in the activities of oxalate oxidase and peroxidase in the roots of wheat seedlings. The most advantageous and most rapidly induced pathway of hydrogen peroxide formation was the oxidation of oxalic acid by oxalate oxidase because in this case, a 10-min treatment of the roots with the lectins at 10 µg ml-1 was sufficient. The data from this study attest that the Azospirillum lectins can act as inducers of adaptation processes in the roots of wheat seedlings.

  20. 绵羊甘露聚糖结合凝集素基因(MBL)全长DNA序列克隆及生物信息学分析%Cloning and Bioinformatics Analysis of Mannan-binding Lectin Gene (MBL) Full-length DNA Sequence in Sheep(Ovis aries)

    Institute of Scientific and Technical Information of China (English)

    赵宗胜; 赵凤; 张红梅; 贾斌; 余鹏; 张慧; 班谦; 王建梅; 王小义

    2012-01-01

    Sheep mannose-binding lectin (MBL) is an important part of the body's natural immune system. Nine pairs of primers were designed according to human (Homo spiens) and bovine (Bos taurus) MBL gene sequence, combined with PCR technique to amplify the MBL gene of sheep (Ovis aries). Cloning, sequencing and splicing to analyze bioinformations with the DNAMAN software and online tools. The results showed that sequence of DNA of the sheep MBL gene was 4 462 bp containing promoter, four exons, three introns, which encoded 249 animo acids, submitted it to GenBank (Accession No. FJ977629). Its amino acid sequence had an overall similarity with a comparable region of bovine MBL-C gene (96.39%), phylogenetic tree of amino acid analysis indicated that the sheep MBL gene was MBL-C. Expasy were employed to predict specific structure and function of sheep MBL gene, 1-19 amino acids were signal peptide region, exon 1 encoded N-terminus cysteine-rich domain and 8 Gly-X-Y repetitive sequences of collagen-like domain, and exon 4 encoded carbohydrate recognition domain (CRD) which had common features of C-type lectin. This study is the first report about complete genomic DNA sequence data of sheep MBL gene, and it provides basal data for further study on the structure, function and defects in the molecular mechanism of MBL.%绵羊甘露聚糖结合凝集素(MBL)是肌体天然免疫系统的重要组成部分.根据人(Homo sapiens)和牛(Bos taurus)的MBL基因序列的同源保守区域,分段设计9对特异性引物,以中国美利奴羊(Ovis aries)血液基因组DNA为模板,经扩增、测序、拼接,首次克隆到长为4 462 bp的绵羊MBL基因组DNA序列,包括了该基因的启动子区、4个外显子和3个内含子,编码249个氨基酸;BLAST分析其与牛MBL-C编码的氨基酸同源性最高为96.39%,判定其为MBL-C型基因,并将该序列提交至GenBank (Accession No.FJ977629);通过Expasy网站预测其蛋白结构功能特征,1~19氨基酸为绵羊MBL

  1. Lectin Histochemical Study of Vasculogenesis During Rat Pituitary Morphogenesis

    Directory of Open Access Journals (Sweden)

    Ali Reza Ebrahimzadeh Bideskan

    2011-01-01

    Full Text Available Objective(s The aim of this study was to investigate glycoconjugates distribution patterns as well as their changes during the course of pituitary portal vasculogenesis and angiogenesis.Materials and MethodsFormalin fixed paraffin sections of 10 to 20 days of Sprague Dawly rat fetuses were processed for histochemical studies using four different horseradish peroxidase (HRP conjugated lectins. Orange peel fungus (OFA, Vicica villosa (VVA, Glycine max (SBA and Wistaria floribunda (WFA specific for α-L-Fucose, D-Gal, α, ß-D-GalNAc and D- GalNAc terminal sugars of glycoconjugates respectively.ResultsOur finding indicated that adenohypophysal cells reacted with OFA on gestational day 10 (E10 and increased progressively to E14. Staining intensity did not change from days 14 to17, then after increased following days to E20 significantly (P< 0.05. A few cells around Rathke’s pouch reacted with VVA on E13, increased to E14 and decreased significantly afterward (P< 0.05. Reaction of some cells around Rathke’s pouch reacted with SBA on E14. This visible reaction was the same as E18 and decreased later (P< 0.05. Many cells around Rathke’s pouch reacted with WFA on E13 and increased on E 14 and E15 and decreased thereafter (P< 0.05.ConclusionReactions of OFA and other tested lectins with endothelial cells around Rathke’s pouch and developing pars distalis were different. These results suggest that embryonic origin of hypophiseal pituitary portal (HPP system endothelial cells are not the same and our finding also indicated that glycoconjugates with terminal sugars α-L-Fucose, D-Gal, α, ß-D-GalNAc may play critical role(s in cell interactions and tissue differentiations such as vasculogensis and angiogenesis as well as other developmental precursors in formation of the pituitary gland.

  2. Interaction indole-3-acetic acid IAA with lectin Canavalia maritima seeds reveal new function of lectins in plant physiology

    Energy Technology Data Exchange (ETDEWEB)

    Silva Filho, J.C.; Santi-Gadelha, T.; Gadelha, C.A.A.; Delatorre, P. [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil); Teixeira, C.S.; Rocha, B.A.M.; Nobrega, R.B.; Alencar, K.L.L.; Cavada, B.S. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil)

    2012-07-01

    Full text: Lectins are a class of proteins of non-immune origin characterized by its capability in interacts specifically and reversibly to mono and oligosaccharides. In plant several possible roles have been suggested including their function in seed maturation, cell wall assembly, defense mechanisms, or rhizobial nodulation of legume roots. Nearly all application and proposed of the plant lectins are based on their specific carbohydrate binding. However, it has been reported that lectins from legumes, might interact with other molecules, such as non proteic amino acids and hydrophobic compounds. This study show the first the crystal structure based on molecular replacement of the Canavalia maritima (CML) complexed with IAA correlated with possible role in plant development. Purified CML was dissolved in 20 mMTrisHCl pH 7.6 containing 5 mM IAA, the suitable co-crystals from CML-IAA complex grew in condition 4 of screen I (0.1 M TrisHCl pH 8.5 and 2.0 M ammonium sulfate). This crystal belong to the orthorhombic space group I222 with unit-cell parameters a = 67.1 ; b = 70.7 , c = 97.7 , The structure was refined at 2.1 of resolution to a final R factor of 20.63 % and an R free of 22.54 %. To check the relative position of the IAA molecule in relation to the biological assemble of the CML, the tetrameric structure was generate by crystallographic symmetry. IAA molecules are positioned in the central cavity. The IAA is stabilized by interacting through hydrogen bounds and Van der Waals forces with the amino acids residues Ser 108 and Asn131, and two water molecules. The hydrophilic interactions occur between IAA and side chains of Ser 108, Asn131 and water molecules 26 and 31 by H-bonds. The OG oxygen from Ser108 display H-bonds with O2 and O3 oxygen atoms from IAA, 3.1 and 2.8 respectively. The tetrameric structure of CML complexed with IAA revels which this protein can act during the seedling in plant development. (author)

  3. Differential effect of plant lectins on mast cells of different origins

    Directory of Open Access Journals (Sweden)

    F.C. Lopes

    2005-06-01

    Full Text Available Histamine release induced by plant lectins was studied with emphasis on the carbohydrate specificity, external calcium requirement, metal binding sites, and mast cell heterogeneity and on the importance of antibodies bound to the mast cell membrane to the lectin effect. Peritoneal mast cells were obtained by direct lavage of the rat peritoneal cavity and guinea pig intestine and hamster cheek pouch mast cells were obtained by dispersion with collagenase type IA. Histamine release was induced with concanavalin A (Con A, lectins from Canavalia brasiliensis, mannose-specific Cymbosema roseum, Maackia amurensis, Parkia platycephala, Triticum vulgaris (WGA, and demetallized Con A and C. brasiliensis, using 1-300 µg/ml lectin concentrations applied to Wistar rat peritoneal mast cells, peaking on 26.9, 21.0, 29.1, 24.9, 17.2, 10.7, 19.9, and 41.5%, respectively. This effect was inhibited in the absence of extracellular calcium. The lectins were also active on hamster cheek pouch mast cells (except demetallized Con A and on Rowett nude rat (animal free of immunoglobulins peritoneal mast cells (except for mannose-specific C. roseum, P. platycephala and WGA. No effect was observed in guinea pig intestine mast cells. Glucose-saturated Con A and C. brasiliensis also released histamine from Wistar rat peritoneal mast cells. These results suggest that histamine release induced by lectins is influenced by the heterogeneity of mast cells and depends on extracellular calcium. The results also suggest that this histamine release might occur by alternative mechanisms, because the usual mechanism of lectins is related to their binding properties to metals from which depend the binding to sugars, which would be their sites to bind to immunoglobulins. In the present study, we show that the histamine release by lectins was also induced by demetallized lectins and by sugar-saturated lectins (which would avoid their binding to other sugars. Additionally, the lectins

  4. cDNA and Gene Structure of MytiLec-1, A Bacteriostatic R-Type Lectin from the Mediterranean Mussel (Mytilus galloprovincialis

    Directory of Open Access Journals (Sweden)

    Imtiaj Hasan

    2016-05-01

    Full Text Available MytiLec is an α-d-galactose-binding lectin with a unique primary structure isolated from the Mediterranean mussel (Mytilus galloprovincialis. The lectin adopts a β-trefoil fold that is also found in the B-sub-unit of ricin and other ricin-type (R-type lectins. We are introducing MytiLec(-1 and its two variants (MytiLec-2 and -3, which both possess an additional pore-forming aerolysin-like domain, as members of a novel multi-genic “mytilectin family” in bivalve mollusks. Based on the full length mRNA sequence (911 bps, it was possible to elucidate the coding sequence of MytiLec-1, which displays an extended open reading frame (ORF at the 5′ end of the sequence, confirmed both at the mRNA and at the genomic DNA sequence level. While this extension could potentially produce a polypeptide significantly longer than previously reported, this has not been confirmed yet at the protein level. MytiLec-1 was revealed to be encoded by a gene consisting of two exons and a single intron. The first exon comprised the 5′UTR and the initial ATG codon and it was possible to detect a putative promoter region immediately ahead of the transcription start site in the MytiLec-1 genomic locus. The remaining part of the MytiLec-1 coding sequence (including the three sub-domains, the 3′UTR and the poly-A signal was included in the second exon. The bacteriostatic activity of MytiLec-1 was determined by the agglutination of both Gram-positive and Gram-negative bacteria, which was reversed by the co-presence of α-galactoside. Altogether, these data support the classification of MytiLec-1 as a member of the novel mytilectin family and suggest that this lectin may play an important role as a pattern recognition receptor in the innate immunity of mussels.

  5. Helicobacter pylori CagA triggers expression of the bactericidal lectin REG3γ via gastric STAT3 activation.

    Directory of Open Access Journals (Sweden)

    Kai Syin Lee

    Full Text Available BACKGROUND: Most of what is known about the Helicobacter pylori (H. pylori cytotoxin, CagA, pertains to a much-vaunted role as a determinant of gastric inflammation and cancer. Little attention has been devoted to potential roles of CagA in the majority of H. pylori infected individuals not showing oncogenic progression, particularly in relation to host tolerance. Regenerating islet-derived (REG3γ encodes a secreted C-type lectin that exerts direct bactericidal activity against Gram-positive bacteria in the intestine. Here, we extend this paradigm of lectin-mediated innate immunity, showing that REG3γ expression is triggered by CagA in the H. pylori-infected stomach. METHODOLOGY/PRINCIPAL FINDINGS: In human gastric mucosal tissues, REG3γ expression was significantly increased in CagA-positive, compared to CagA-negative H. pylori infected individuals. Using transfected CagA-inducible gastric MKN28 cells, we recapitulated REG3γ induction in vitro, also showing that tyrosine phosphorylated, not unphosphorylated CagA triggers REG3γ transcription. In concert with induced REG3γ, pro-inflammatory signalling downstream of the gp130 cytokine co-receptor via the signal transducer and activator of transcription (STAT3 and transcription of two cognate ligands, interleukin(IL-11 and IL-6, were significantly increased. Exogenous IL-11, but not IL-6, directly stimulated STAT3 activation and REG3γ transcription. STAT3 siRNA knockdown or IL-11 receptor blockade respectively abrogated or subdued CagA-dependent REG3γ mRNA induction, thus demonstrating a requirement for uncompromised signalling via the IL-11/STAT3 pathway. Inhibition of the gp130-related SHP2-(Ras-ERK pathway did not affect CagA-dependent REG3γ induction, but strengthened STAT3 activation as well as augmenting transcription of mucosal innate immune regulators, IL-6, IL-8 and interferon-response factor (IRF1. CONCLUSIONS/SIGNIFICANCE: Our results support a model of CagA-directed REG3

  6. Stability of Curcuma longa rhizome lectin: Role of N-linked glycosylation.

    Science.gov (United States)

    Biswas, Himadri; Chattopadhyaya, Rajagopal

    2016-04-01

    Curcuma longa rhizome lectin, a mannose-binding protein of non-seed portions of turmeric, is known to have antifungal, antibacterial and α-glucosidase inhibitory activities. We studied the role of complex-type glycans attached to asparagine (Asn) 66 and Asn 110 to elucidate the role of carbohydrates in lectin activity and stability. Apart from the native lectin, the characteristics of a deglycosylated Escherichia coli expressed lectin, high-mannose oligosaccharides at both asparagines and its glycosylation mutants N66Q and N110Q expressed in Pichia pastoris, were compared to understand the relationship between glycosylation and activity. Far UV circular dichroism (CD) spectra, fluorescence emission maximum, hemagglutination assay show no change in secondary or tertiary structures or sugar-binding properties between wild-type and aforementioned recombinant lectins under physiological pH. But reduced agglutination activity and loss of tertiary structure are observed in the acidic pH range for the deglycosylated and the N110Q protein. In thermal and guanidine hydrochloride (GdnCl)-induced unfolding, the wild-type and high-mannose lectins possess higher stability compared with the deglycosylated recombinant lectin and both mutants, as measured by a higher Tm of denaturation or a greater free energy change, respectively. Reversibility experiments after thermal denaturation reveal that deglycosylated proteins tend to aggregate during thermal inactivation but the wild type shows a much greater recovery to the native state upon refolding. These results suggest that N-glycosylation in turmeric lectin is important for the maintenance of its proper folding upon changes in pH, and that the oligosaccharides help in maintaining the active conformation and prevent aggregation in unfolded or partially folded molecules.

  7. Isolation and antiproliferative activity of Lotus corniculatus lectin towards human tumour cell lines.

    Science.gov (United States)

    Rafiq, Shaista; Majeed, Rabiya; Qazi, Asif Khurshid; Ganai, Bashir Ahmad; Wani, Ishfak; Rakhshanda, Syed; Qurishi, Yasrib; Sharma, P R; Hamid, Abid; Masood, Akbar; Hamid, Rabia

    2013-12-15

    The objective of the study was to investigate the anti cancer activity of a lectin isolated from Lotus corniculatus seeds. A tetrameric 70kDa galactose specific lectin was purified using two step simple purification protocol which involved affinity chromatography on AF-BlueHC650M and gel filtration on Sephadex G-100. The lectin was adsorbed on AF-BlueHC650M and desorbed using 1M NaCl in the starting buffer. Gel filtration on Sephadex G-100 yielded a major peak absorbance that gave two bands of 15kDa and 20kDa in SDS PAGE. Hemagglutination activity was completely preserved, when the temperature was in the range of 20-60°C. However, drastic reduction in activity occurred at temperatures above 60°C. Full hemagglutination activity was retained at ambient pH 4-12. Thereafter no activity was observed above pH 13. Hemaglutination of the lectin was inhibited by d-galactose. The lectin showed a strong antiproliferative activity towards human leukemic (THP-1) cancer cells followed by lung cancer (HOP62) cells and HCT116 with an IC50 of 39μg/ml and 50μg/ml and 60μg/ml respectively. Flow cytometry analysis showed an increase in the percentage of cells in sub G0G1 phase confirming that Lotus corniculatus lectin induced apoptosis. Morphological observations showed that Lotus corniculatus lectin (LCL) treated THP-1 cells displayed apparent apoptosis characteristics such as nuclear fragmentation, appearance of membrane enclosed apoptotic bodies and DNA fragmentation. Lotus corniculatus lectin (LCL) effectively inhibits the cell migration in a dose dependent manner as indicated by the wound healing assay.

  8. Molecular cloning and characterization of multiple isoforms of the snowdrop (Galanthus nivalis L.) lectin.

    Science.gov (United States)

    Van Damme, E J; De Clercq, N; Claessens, F; Hemschoote, K; Peeters, B; Peumans, W J

    1991-12-01

    Screening of a copy-DNA (cDNA) library constructed from RNA isolated from young developing ovaries of snowdrop (Galanthus nivalis) resulted in the isolation of five lectin clones which clearly differed from each other with regard to their nucleotide sequence and deduced amino-acid sequence. Sequence comparison between the coding regions of different lectin cDNAs revealed the highest homology between lectin clones LECGNA 3 and LECGNA 5, showing 96.4% and 93.6% similarity at the nucleotide level and at the deduced amino-acid level, respectively, whereas lectin clones LECGNA 1 and LECGNA 3 showed the lowest homology of 81.6% and 68.6% for the nucleotide sequence and the amino-acid sequence, respectively. Only very few lectin cDNA clones containing a polyadenylated tail could be isolated. Moreover all these cDNA clones were derived from isolectin 3 and showed some variability within the length of the 3' untranslated region. The major transcription initiation site was located 30 bases upstream from the AUG codon as could be deduced from primer-extension analysis. Taking into account the small 5' untranslated region of the lectin clones, the size of the lectin mRNA, which is approx. 780 nucleotides as determined by Northern blot analysis, is in good agreement with the length of the cDNA clones isolated. Besides the ovary tissue, both the leaf and the flower tissue were also shown to express the lectin mRNA in a flowering snowdrop plant.

  9. Domain crossing

    DEFF Research Database (Denmark)

    Schraefel, M. C.; Rouncefield, Mark; Kellogg, Wendy

    2012-01-01

    In CSCW, how much do we need to know about another domain/culture before we observe, intersect and intervene with designs. What optimally would that other culture need to know about us? Is this a “how long is a piece of string” question, or an inquiry where we can consider a variety of contexts a...

  10. Dexamethasone stimulates expression of C-type Natriuretic Peptide in chondrocytes

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    Beier Frank

    2006-11-01

    Full Text Available Abstract Background Growth of endochondral bones is regulated through the activity of cartilaginous growth plates. Disruption of the physiological patterns of chondrocyte proliferation and differentiation – such as in endocrine disorders or in many different genetic diseases (e.g. chondrodysplasias – generally results in dwarfism and skeletal defects. For example, glucocorticoid administration in children inhibits endochondral bone growth, but the molecular targets of these hormones in chondrocytes remain largely unknown. In contrast, recent studies have shown that C-type Natriuretic Peptide (CNP is an important anabolic regulator of cartilage growth, and loss-of-function mutations in the human CNP receptor gene cause dwarfism. We asked whether glucocorticoids could exert their activities by interfering with the expression of CNP or its downstream signaling components. Methods Primary mouse chondrocytes in monolayer where incubated with the synthetic glucocorticoid Dexamethasone (DEX for 12 to 72 hours. Cell numbers were determined by counting, and real-time PCR was performed to examine regulation of genes in the CNP signaling pathway by DEX. Results We show that DEX does influence expression of key genes in the CNP pathway. Most importantly, DEX significantly increases RNA expression of the gene encoding CNP itself (Nppc. In addition, DEX stimulates expression of Prkg2 (encoding cGMP-dependent protein kinase II and Npr3 (natriuretic peptide decoy receptor genes. Conversely, DEX was found to down-regulate the expression of the gene encoding its receptor, Nr3c1 (glucocorticoid receptor, as well as the Npr2 gene (encoding the CNP receptor. Conclusion Our data suggest that the growth-suppressive activities of DEX are not due to blockade of CNP signaling. This study reveals a novel, unanticipated relationship between glucocorticoid and CNP signaling and provides the first evidence that CNP expression in chondrocytes is regulated by endocrine

  11. Thermal Infrared Imaging Experiments of C-Type Asteroid 162173 Ryugu on Hayabusa2

    Science.gov (United States)

    Okada, Tatsuaki; Fukuhara, Tetsuya; Tanaka, Satoshi; Taguchi, Makoto; Imamura, Takeshi; Arai, Takehiko; Senshu, Hiroki; Ogawa, Yoshiko; Demura, Hirohide; Kitazato, Kohei; Nakamura, Ryosuke; Kouyama, Toru; Sekiguchi, Tomohiko; Hasegawa, Sunao; Matsunaga, Tsuneo; Wada, Takehiko; Takita, Jun; Sakatani, Naoya; Horikawa, Yamato; Endo, Ken; Helbert, Jörn; Müller, Thomas G.; Hagermann, Axel

    2016-09-01

    The thermal infrared imager TIR onboard Hayabusa2 has been developed to investigate thermo-physical properties of C-type, near-Earth asteroid 162173 Ryugu. TIR is one of the remote science instruments on Hayabusa2 designed to understand the nature of a volatile-rich solar system small body, but it also has significant mission objectives to provide information on surface physical properties and conditions for sampling site selection as well as the assessment of safe landing operations. TIR is based on a two-dimensional uncooled micro-bolometer array inherited from the Longwave Infrared Camera LIR on Akatsuki (Fukuhara et al., 2011). TIR takes images of thermal infrared emission in 8 to 12 μm with a field of view of 16 × 12° and a spatial resolution of 0.05° per pixel. TIR covers the temperature range from 150 to 460 K, including the well calibrated range from 230 to 420 K. Temperature accuracy is within 2 K or better for summed images, and the relative accuracy or noise equivalent temperature difference (NETD) at each of pixels is 0.4 K or lower for the well-calibrated temperature range. TIR takes a couple of images with shutter open and closed, the corresponding dark frame, and provides a true thermal image by dark frame subtraction. Data processing involves summation of multiple images, image processing including the StarPixel compression (Hihara et al., 2014), and transfer to the data recorder in the spacecraft digital electronics (DE). We report the scientific and mission objectives of TIR, the requirements and constraints for the instrument specifications, the designed instrumentation and the pre-flight and in-flight performances of TIR, as well as its observation plan during the Hayabusa2 mission.

  12. c-Type cytochrome-dependent formation of U(IV nanoparticles by Shewanella oneidensis.

    Directory of Open Access Journals (Sweden)

    Matthew J Marshall

    2006-09-01

    Full Text Available Modern approaches for bioremediation of radionuclide contaminated environments are based on the ability of microorganisms to effectively catalyze changes in the oxidation states of metals that in turn influence their solubility. Although microbial metal reduction has been identified as an effective means for immobilizing highly-soluble uranium(VI complexes in situ, the biomolecular mechanisms of U(VI reduction are not well understood. Here, we show that c-type cytochromes of a dissimilatory metal-reducing bacterium, Shewanella oneidensis MR-1, are essential for the reduction of U(VI and formation of extracellular UO(2 nanoparticles. In particular, the outer membrane (OM decaheme cytochrome MtrC (metal reduction, previously implicated in Mn(IV and Fe(III reduction, directly transferred electrons to U(VI. Additionally, deletions of mtrC and/or omcA significantly affected the in vivo U(VI reduction rate relative to wild-type MR-1. Similar to the wild-type, the mutants accumulated UO(2 nanoparticles extracellularly to high densities in association with an extracellular polymeric substance (EPS. In wild-type cells, this UO(2-EPS matrix exhibited glycocalyx-like properties and contained multiple elements of the OM, polysaccharide, and heme-containing proteins. Using a novel combination of methods including synchrotron-based X-ray fluorescence microscopy and high-resolution immune-electron microscopy, we demonstrate a close association of the extracellular UO(2 nanoparticles with MtrC and OmcA (outer membrane cytochrome. This is the first study to our knowledge to directly localize the OM-associated cytochromes with EPS, which contains biogenic UO(2 nanoparticles. In the environment, such association of UO(2 nanoparticles with biopolymers may exert a strong influence on subsequent behavior including susceptibility to oxidation by O(2 or transport in soils and sediments.

  13. A seedling specific vegetative lectin gene is related to development in Cicer arietinum.

    Science.gov (United States)

    Esteban, Rocío; Dopico, Berta; Muñoz, Francisco J; Romo, Silvia; Labrador, Emilia

    2002-04-01

    Plant lectins are a group of glycoproteins with the ability to recognize and bind carbohydrate ligands. Seed lectins function as storage and defense proteins, but the specific function of vegetative lectins is uncertain. In this paper we describe the characterization of a clone, CanVLEC, encoding a vegetative lectin from chickpea (Cicer arietinum L. cv. Castellana). The expression of the CanVLEC gene was specific in seedlings, mostly in hooks and elongating epicotyls, and no expression was detected in adult plants. The level of chickpea vegetative lectin transcripts in epicotyls decreased through the epicotyl growth suggesting a relationship to development. Treatment with indoleacetic acid (IAA) and brassinolides (BR), hormones that promoted elongation in chickpea epicotyl, increased the level of CanVLEC mRNA, supporting a relationship to growth. CanVLEC is drastically down regulated by water deficit ruling out its possible involvement in plant response to water stress, unlike other vegetative lectins. CanVLEC protein may be targeted to an extracellular location owing to the presence of a signal peptide.

  14. Evaluation of Caesalpinia pulcherrima endospermic gum as affinity matrices for galactose-binding lectins interaction

    Directory of Open Access Journals (Sweden)

    Renata Chastinet Braga

    2011-04-01

    Full Text Available Lectins are proteins or glycoproteins able to bind, specifically and reversibly carbohydrates and glycoconjugates. Considering this ability, the utilization of Caesalpinia pulcherrima seeds polysaccharides as an affinity matrix was tested. The endospermic gum were solubilized in distinct concentrations of NaOH and treated with different amounts of epichlorohydrin (ECH forming affinity gels with variable capacity for interaction with galactose- binding lectins. The gel with an ECH/gum ration of 6.0mmol/g was selected as the best affinity matrix. The matrix presented different efficiencies in terms of isolating galactose-binding lectins. C. pulcherrima endospermic galactomannans were purified by ethanol precipitation and the purified galactomannan was crosslinked with the best formulation of gel. The Artocarpus incisa, Ricinus communis and Abrus precatorius lectins showed interactions of 11.5, 17.7 and 47.2mg of retained protein in 1g of gel, respectively; the Artocarpus integrifolia lectin showed the highest affinities (79.7mg/g. The heamaglutination assays confirmed the activity and SDS-PAGE electrophoresis confirmed the isolation of the lectins in a single-step procedure.

  15. Selectivity among two lectins: probing the effect of topology, multivalency and flexibility of "clicked" multivalent glycoclusters.

    Science.gov (United States)

    Cecioni, Samy; Faure, Sophie; Darbost, Ulrich; Bonnamour, Isabelle; Parrot-Lopez, Hélène; Roy, Olivier; Taillefumier, Claude; Wimmerová, Michaela; Praly, Jean-Pierre; Imberty, Anne; Vidal, Sébastien

    2011-02-11

    The design of multivalent glycoconjugates has been developed over the past decades to obtain high-affinity ligands for lectin receptors. While multivalency frequently increases the affinity of a ligand for its lectin through the so-called "glycoside cluster effect", the binding profiles towards different lectins have been much less investigated. We have designed a series of multivalent galactosylated glycoconjugates and studied their binding properties towards two lectins, from plant and bacterial origins, to determine their potential selectivity. The synthesis was achieved through copper(I)-catalysed azide-alkyne cycloaddition (CuAAC) under microwave activation between propargylated multivalent scaffolds and an azido-functionalised carbohydrate derivative. The interactions of two galactose-binding lectins from Pseudomonas aeruginosa (PA-IL) and Erythrina cristagalli (ECA) with the synthesized glycoclusters were studied by hemagglutination inhibition assays (HIA), surface plasmon resonance (SPR) and isothermal titration microcalorimetry (ITC). The results obtained illustrate the influence of the scaffold's geometry on the affinity towards the lectin and also on the relative potency in comparison with a monovalent galactoside reference probe.

  16. Effect of leguminous lectins on the growth of Rhizobium tropici CIAT899.

    Science.gov (United States)

    de Vasconcelos, Mayron Alves; Cunha, Cláudio Oliveira; Arruda, Francisco Vassiliepe Sousa; Carneiro, Victor Alves; Bastos, Rafaela Mesquita; Mercante, Fábio Martins; do Nascimento, Kyria Santiago; Cavada, Benildo Sousa; dos Santos, Ricardo Pires; Teixeira, Edson Holanda

    2013-05-17

    Rhizobium tropici is a Gram-negative bacterium that induces nodules and fixed atmospheric nitrogen in symbiotic association with Phaseolus vulgaris (common bean) and some other leguminous species. Lectins are proteins that specifically bind to carbohydrates and, consequently, modulate different biological functions. In this study, the d-glucose/ d-mannose-binding lectins (from seeds of Dioclea megacarpa, D. rostrata and D. violacea) and D-galactose-binding lectins (from seeds of Bauhinia variegata, Erythina velutina and Vatairea macrocarpa) were purified using chromatographic techniques and evaluated for their effect on the growth of R. tropici CIAT899. All lectins were assayed with a satisfactory degree of purity according to SDS-PAGE analysis, and stimulated bacterial growth; in particular, the Dioclea rostrata lectin was the most active among all tested proteins. As confirmed in the present study, both d-galactose- and d-glucose/d-mannose-binding lectins purified from the seeds of leguminous plants may be powerful biotechnological tools to stimulate the growth of R. tropici CIAT99, thus improving symbiotic interaction between rhizobia and common bean and, hence, the production of this field crop.

  17. Effect of Leguminous Lectins on the Growth of Rhizobium tropici CIAT899

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    Mayron Alves de Vasconcelos

    2013-05-01

    Full Text Available Rhizobium tropici is a Gram-negative bacterium that induces nodules and fixed atmospheric nitrogen in symbiotic association with Phaseolus vulgaris (common bean and some other leguminous species. Lectins are proteins that specifically bind to carbohydrates and, consequently, modulate different biological functions. In this study, the d-glucose/ d-mannose-binding lectins (from seeds of Dioclea megacarpa, D. rostrata and D. violacea and D-galactose-binding lectins (from seeds of Bauhinia variegata, Erythina velutina and Vatairea macrocarpa were purified using chromatographic techniques and evaluated for their effect on the growth of R. tropici CIAT899. All lectins were assayed with a satisfactory degree of purity according to SDS-PAGE analysis, and stimulated bacterial growth; in particular, the Dioclea rostrata lectin was the most active among all tested proteins. As confirmed in the present study, both d-galactose- and d-glucose/d-mannose-binding lectins purified from the seeds of leguminous plants may be powerful biotechnological tools to stimulate the growth of R. tropici CIAT99, thus improving symbiotic interaction between rhizobia and common bean and, hence, the production of this field crop.

  18. Purification of melibiose-binding lectins from two cultivars of Chinese black soybeans

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A dimeric 50 kDa melibiose-binding leetin was isolated from the seeds of the cultivar of soybean (Glycine max), called the small glossy black soybean. The isolation procedure comprised ion exchange chromatography on Q Sepharose, SP Sepharose and Mono Q followed by gel filtration on Superdex 75. The lectin was adsorbed on all three ion exchangers, and it exhibited an N-terminal sequence identical to that of soybean iectin. Of all the sugars tested, melibiose most potently inhibited the hemagglutinating activity of the lectin, which was stable between pH 3-12 and 0-70℃. The lectin evoked maximal mitogenic response at about the same molar concentration as Con A. However, the response was much weaker. The soybean iectin inhibited the activity of HIV-1 reverse transcriptase as well as the proliferation of breast cancer MCF7 cells and hepatoma HepG2 cells with an IC of 2.82 μM, 2.6 μM and 4.1 μM, respectively. There was no antifungal activity. Another lectin was isolated from a different cnltivar of soybean called little black soybean. The lectin was essentially similar to small glossy black soy-bean iectin except for a larger subunit molecular mass (31 kDa), a more potent mitogenic activity and lower thermostability. The results indicate that different cultivars of soybean produce lectins that are not identical in every aspect.

  19. Molecular Characterization of a New Lectin from the Marine Alga Ulva pertusa

    Institute of Scientific and Technical Information of China (English)

    ShengWANG; Fu-DiZHONG; Yong-JiangZHANG; Zu-JianWU; Qi-YingLIN; Lian-HuiXIE

    2004-01-01

    A new lectin, named UPL1, was purified from a green alga Ulvapertusa by an affinitychromatography on the bovine-thyroglobulin-Sepharose 4B column. The molecular mass of the algal lectinwas about 23 kD by SDS-PAGE, and it specifically agglutinated rabbit erythrocytes. The hemagglutinatingactivity for rabbit erythrocytes could be inhibited by bovine thyroglobulin and N-acetyl-D-glucosamine. Thelectin UPL1 required divalent cations for maintenance of its biological activity, and was heat-stable, and hadhigher activity within pH 6-8. The N-terminal amino acid sequence of the purified lectin was determined(P83209) and a set of degenerate primers were designed. The full-length cDNA of the lectin was cloned byrapid amplification ofcDNA ends (RACE) method (AY433960). Sequence analysis of upll indicated it was! 084 bp long, and encoded a premature protein of 203 amino acids. The N-terminal sequence of the matureUPL1 polypeptide started at amino acid 54 of the deduced sequence from the cDNA, indicating 53 aminoacids lost due to posttranslational modification. The primary structure of the Ulva pertusa lectin did not showamino acid sequence similarity with known plant and animal lectins. Hence, this protein may be the paradigmof a novel lectin family.

  20. Molecular Characterization of a New Lectin from the Marine Alga Ulva pertusa

    Institute of Scientific and Technical Information of China (English)

    Sheng WANG; Fu-Di ZHONG; Yong-Jiang ZHANG; Zu-Jian WU; Qi-Ying LIN; Lian-Hui XIE

    2004-01-01

    A new lectin, named UPL1, was purified from a green alga Ulvapertusa by an affinitychromatography on the bovine-thyroglobulin-Sepharose 4B column. The molecular mass of the algal lectinwas about 23 kD by SDS-PAGE, and it specifically agglutinated rabbit erythrocytes. The hemagglutinatingactivity for rabbit erythrocytes could be inhibited by bovine thyroglobulin and N-acetyl-D-glucosamine. Thelectin UPL1 required divalent cations for maintenance of its biological activity, and was heat-stable, and hadhigher activity within pH 6-8. The N-terminal amino acid sequence of the purified lectin was determined(P83209) and a set of degenerate primers were designed. The full-length cDNA of the lectin was cloned byrapid amplification of cDNA ends (RACE) method (AY433960). Sequence analysis of upl1 indicated it was1084 bp long, and encoded a premature protein of 203 amino acids. The N-terminal sequence of the matureUPL1 polypeptide started at amino acid 54 of the deduced sequence from the cDNA, indicating 53 aminoacids lost due to posttranslational modification. The primary structure of the Ulvapertusa lectin did not showamino acid sequence similarity with known plant and animal lectins. Hence, this protein may be the paradigmof a novel lectin family.

  1. A lectin-based glycomic approach to identify characteristic features of Xenopus embryogenesis.

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    Yasuko Onuma

    Full Text Available Cell surface glycans show dynamic changes during cell differentiation. Several glycans are useful biomarkers of tumors, stem cells, and embryogenesis. Glycomic studies have been performed using liquid chromatography and mass spectrometry, which are powerful tools for glycan structural analysis but are difficult to use for small sample sizes. Recently, a lectin microarray system was developed for profiling cell surface glycome changes to terminal carbohydrate chains and branch types, using sample sizes of a few micrograms. In this study, we used the lectin microarray system for the first time to investigate stage-specific glycomes in Xenopus laevis embryos. Unsupervised cluster analysis of lectin microarray data indicated that glycan profiles changed sequentially during development. Nine lectin probes showed significantly different signals between early and the late-stage embryos: 4 showed higher signals in the early stages, and 5 exhibited higher signals in the late stages. The gene expression profiles of relevant glycosyltransferase genes support the lectin microarray data. Therefore, we have shown that lectin microarray is an effective tool for high-throughput glycan analysis in Xenopus embryogenesis, allowing glycan profiling of early embryos and small biopsy specimens.

  2. Isolation and Characterization of Midgut Lectin From Aedes aegypti (L. (Diptera: Culicidae

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    Tahany Hassan Ayaad

    2015-12-01

    Full Text Available ABSTRACT The present investigation deals with the isolation and characterization of a lectin from Aedes aegypti (Ae aegypti female mid gut extract that agglutinates various mammalian red blood cells (RBCs such as human three groups A, B, and O (RH+, mouse, rat, guinea-pig, sheep and goat erythrocytes. The highest activity of both crude and isolated mid gut lectins were detected against sheep RBCs. Using (NH42 SO4 fractionation, ion-exchange and mannose-CNBr-Sepharose 6B affinity chromatography techniques, Ae. aegypti midgut lectin (Aelec was purified to homogeneity.Isoelectric focusing (IEF and reducing SDS/PAGE revealed that the isolated mid gut lectin had isoelectric point (PI of 5.90, and subunits approximate molecular weights of 35.50 and 27.35 KDa. The hemagglutination (HA of lectins were Ca2+ - independent and heat-resistant. The sugar specificity of the purified Aelec was strongly inhibited by D (+-mannose and raffinose, followed by D (+ glucose. N-acetyl-D-manosamine and N-acetyl-D-glucosamine were moderate inhibitors. None of the lectins were inhibited by the disaccharides such as galactose, lactose, trehalose (IC50 up to 200 mM or fetuin up to 1% but the glycosubstances mucin and laminarin were strong inhibitors up to very low concentrations (0.030 - 0.003%.

  3. Interaction of a human blood group Sd(a-) Tamm-Horsfall glycoprotein with applied lectins.

    Science.gov (United States)

    Wu, J H; Watkins, W M; Chen, C P; Song, S C; Wu, A M

    1996-04-22

    Unlike the human blood group Sd(a+) Tamm-Horsfall glycoprotein (THGP), the Sd(a-) one lacks terminal GalNAcbeta1--> residues at the nonreducing ends. The binding properties of this glycoprotein and its asialo product with lectins were characterized by quantitative precipitin (QPA) and precipitin inhibition assays. Among 20 lectins tested by QPA, both native and asialo Sd(a-) THGP reacted best with Abrus precatorius and Ricinus communis and completely precipitated the lectin added. They also precipitated well Wistaria floribunda (WFA), Glycine max (SBA), Bauhinia purpurea alba, abrin-a and ricin, all of which recognize the Galbeta1--> 4GlcNAcbeta1--> sequence, although at different strength. The lectin-glycan interactions were inhibited by Galbeta1--> 4GlcNAc and Galbeta1--> 4Glc. When the precipitability of Sd(a-) THGP was compared with that of the Sd(a+) phenotype, the native Sd(a-) THGP exhibited a 40% lesser affinity for WFA, SBA, WGA and mistletoe lectin-I (ML-I). Mapping the precipitation and inhibition profiles of the present study and the results of THGP Sd(a+), it is concluded that Sd(a-) THGP showed a strongly diminished affinity for GalNAcbeta1--> active lectins (SBA and WFA) than the Sd(a+) phenotype.

  4. Integrated Microfluidic Lectin Barcode Platform for High-Performance Focused Glycomic Profiling.

    Science.gov (United States)

    Shang, Yuqin; Zeng, Yun; Zeng, Yong

    2016-02-02

    Protein glycosylation is one of the key processes that play essential roles in biological functions and dysfunctions. However, progress in glycomics has considerably lagged behind genomics and proteomics, due in part to the enormous challenges in analysis of glycans. Here we present a new integrated and automated microfluidic lectin barcode platform to substantially improve the performance of lectin array for focused glycomic profiling. The chip design and flow control were optimized to promote the lectin-glycan binding kinetics and speed of lectin microarray. Moreover, we established an on-chip lectin assay which employs a very simple blocking method to effectively suppress the undesired background due to lectin binding of antibodies. Using this technology, we demonstrated focused differential profiling of tissue-specific glycosylation changes of a biomarker, CA125 protein purified from ovarian cancer cell line and different tissues from ovarian cancer patients in a fast, reproducible, and high-throughput fashion. Highly sensitive CA125 detection was also demonstrated with a detection limit much lower than the clinical cutoff value for cancer diagnosis. This microfluidic platform holds the potential to integrate with sample preparation functions to construct a fully integrated "sample-to-answer" microsystem for focused differential glycomic analysis. Thus, our technology should present a powerful tool in support of rapid advance in glycobiology and glyco-biomarker development.

  5. Screening of lectins from South American plants used as affinity ligands to purify rhEPO

    Directory of Open Access Journals (Sweden)

    G.I. Amadeo

    2003-03-01

    Full Text Available Two groups of isoforms of rhEPO, at a concentration of 300 µg/ml, were tested as putative inhibitors of the lectinic hemagglutination reaction in order to obtain affinity ligand(s for hormone purification: groups I (pI: 3.80; 3.89; 3.95; 4.07, 4.15 and 4.26 and groups II (pI: 4.15, 4.26; 4.38; 4.51; 4.72 and 4.93 Crude extracts from the vegetable materials Abrus precatorious (Abrin, Artocarpus incisa (Frutalin, Artocarpus integrifolia (Jacalin, Canavalia ensiformes (ConA, Canavalia brasiliensis (Conbr, Cratylia floribunda, Dioclea altissima (DAL, Dioclea grandiflora (DGL, Erythrina vellutina (EVL, Erythrina cristagalli, Lutaelburgia auriculata (lectin not fully characterized yet, Lycopersicum esculentum (LEA, Phaseolus vulgaris (PHA, Ricinus communis (Ricin and Triticum vulgaris (WGA were used. Only some of the galactose-specific lectins and the GlcNAc-specific lectins showed rapid full inhibition of the hemagglutination reaction for the less acidic isoforms and the total isoforms of rhEPO, respectively. On this basis, the selected lectins were purified by affinity chromatoghraphy and covalently coupled to cyanogen bromide activated Sepharose® (Amersham-Pharmacia. CHO.K1 cell culture supernatant containing rhEPO was loaded onto the lectin resins and the recoveries were calculated by using specific elutions.

  6. Absence of C-type virus production in human leukemic B cell, T cell and null cell lines.

    Directory of Open Access Journals (Sweden)

    Ogura,Hajime

    1978-06-01

    Full Text Available Electron microscope observation of cultured human leukemic B cell, T cell and null cell lines and reverse transcriptase assay of the culture supernatants were all negative for the presence of C-type virus. Bat cell line, which propagates primate C-type viruses well, was cocultivated with the human leukemic cell lines, in the hope of amplification of virus if present. Three weeks after mixed culture, the culture supernatants were again examined for reverse transcriptase activity and the cells were tested for syncytia formation by cocultivation with rat XC, human KC and RSb cell lines. All these tests, except for the positive control using a simian sarcoma virus, were negative, suggesting that no C-type was produced from these human leukemic cell lines.

  7. Tumor-associated Tn-MUC1 glycoform is internalized through the macrophage galactose-type C-type lectin and delivered to the HLA class I and II compartments in dendritic cells

    DEFF Research Database (Denmark)

    Napoletano, Chiara; Rughetti, Aurelia; Agervig Tarp, Mads P;

    2007-01-01

    and ELISA done on subcellular fractions of iDCs showed that the Tn-MUC1 glycopeptides colocalized with HLA class I and II compartments after internalization. Importantly, although Tn-MUC1 recombinant protein was bound and internalized by MGL, the glycoprotein entered the HLA class II compartment......, but not the HLA class I pathway. These data indicate that MGL expressed on iDCs is an optimal receptor for the internalization of short GalNAcs carrying immunogens to be delivered into HLA class I and II compartments. Such glycopeptides therefore represent a new way of targeting the HLA class I and II pathways...

  8. Detection of Cytotoxic Activity of Lectin on Human Colon Adenocarcinoma (Sw480 and Epithelial Cervical Carcinoma (C33-A

    Directory of Open Access Journals (Sweden)

    Mirandeli Bautista

    2011-03-01

    Full Text Available Lectins comprise a heterogeneous class of proteins that recognize the carbohydrate moieties of glycoconjugates with high specificity. Numerous studies have shown that lectins are capable of recognizing specific carbohydrate moieties displayed by malignant cells or tissues. The present work was performed to investigate the effects of tepary bean (Phaseolus acutifolius lectins on proliferation, colony formation, and alteration of DNA synthesis of human malignant cells. Tepary bean lectin showed dose dependent  effects on the inhibition of viability as well as on colony formation in two human malignant cells lines (C33-A, Sw480; By contrast, tepary bean lectin only showed significant effects on DNA synthesis on Sw480 cells. Our results provide evidence of the anti- proliferative and cytotoxic effects of the tepary bean lectins on C33-A and Sw480 cells lines.

  9. [Effect of Azospirillum lectins on the Activity of Proteolytic Enzymes and Their Inhibitors in Wheat Seedling Roots].

    Science.gov (United States)

    Alen'kina, S A; Nikitina, V E

    2015-01-01

    The lectins of associative nitrogen-fixing strains Azospirillum brasilense Sp7 and Sp245 were shown to exerte a multidirectional effect on the activity of acidic (pH 3.5), neutral (6.8), and alkaline (pH 7.8) proteinases. The lectin of the epiphytic A. brasilense Sp7 decreased proteolytic activity at all pH values, whereas the lectin of the endophytic A. brasilense Sp245 activated neutral and alkaline proteinases, while not affecting the alkaline ones. Experiments with protease inhibitors made it possible to conclude that the lectins of the studied A. brasilense strains alter the ratio between the activities of different protease types in germinating seeds. The activity of trypsin inhibitors in wheat seedling roots was found to increase in the presence of the lectins. Our results indicate a broader spectrum of effects of azospirilla lectins on the host plant organism.

  10. A lectin extracted from Citrullus colocynthis L. (Cucurbitaceae) inhibits digestive α-amylase of Ectomyelois ceratoniae Zeller (Lepidoptera: Pyralidae)

    OpenAIRE

    S. Ramzi; A. Sahragard

    2013-01-01

    A lectin was extracted from seeds of Citrullus colocynthis (Cucurbitaceae) by column chromatography using Sepharose 4BGalactose and DEAE-Cellulose fast flow. The inhibitory effects of the extracted lectin on digestive α-amylase of Ectomyelois ceratoniae larvae were studied using pH, temperature, time of incubation and kinetic parameters. Different concentrations of extracted lectin, Citrullus colocynthis agglutinin (CCA), inhibited digestive amylolytic activity by 22-49%. The highest inhibiti...

  11. Trusted Domain

    DEFF Research Database (Denmark)

    Hjorth, Theis Solberg; Torbensen, Rune

    2012-01-01

    In the digital age of home automation and with the proliferation of mobile Internet access, the intelligent home and its devices should be accessible at any time from anywhere. There are many challenges such as security, privacy, ease of configuration, incompatible legacy devices, a wealth...... remote access via IP-based devices such as smartphones. The Trusted Domain platform fits existing legacy technologies by managing their interoperability and access controls, and it seeks to avoid the security issues of relying on third-party servers outside the home. It is a distributed system...... of wireless standards, limited resources of embedded systems, etc. Taking these challenges into account, we present a Trusted Domain home automation platform, which dynamically and securely connects heterogeneous networks of Short-Range Wireless devices via simple non-expert user. interactions, and allows...

  12. Differential binding properties of Gal/GalNAc specific lectins available for characterization of glycoreceptors.

    Science.gov (United States)

    Wu, A M; Song, S C; Sugii, S; Herp, A

    1997-01-01

    Differentiating the binding properties of applied lectins should facilitate the selection of lectins for characterization of glycoreceptors on the cell surface. Based on the binding specificities studied by inhibition assays of lectin-glycan interactions, over twenty Gal and/or GalNAc specific lectins have been divided into eight groups according to their specificity for structural units (lectin determinants), which are the disaccharide as all or part of the determinants and of GalNAc alpha 1-->Ser (Thr) of the peptide chain. A scheme of codes for lectin determinants is illustrated as follows: (1) F (GalNAc alpha 1-->3GalNAc), Forssman specific disaccharide--Dolichos biflorus (DBL), Helix pomatia (HPL) and Wistaria floribunda (WFL) lectins. (2) A (GalNAc alpha 1-->3 Gal), blood group A specific disaccharide--Codium fragile subspecies tomentosoides (CFT), Soy bean (SBL), Vicia villosa-A4 (VVL-A4), and Wistaria floribunda (WFL) lectins. (3) Tn (GalNAc alpha 1-->Ser (Thr) of the protein core)--Vicia villosa B4 (VVL-B4), Salvia sclarea (SSL), Maclura pomifera (MPL), Bauhinia purpurea alba (BPL) and Artocarpus integrifolia (Jacalin, AIL). (4) T (Gal beta 1-->3GalNAc), the mucin type sugar sequences on the human erythrocyte membrane(T alpha), T antigen or the disaccharides at the terminal nonreducing end of gangliosides (T beta)--Peanut (PNA), Bauhinia purpurea alba (BPL), Maclura pomifera (MPL), Sophora japonica (SJL), Artocarpus lakoocha (Artocarpin) lectins and Abrus precatorius agglutinin (APA).(5) I and II (Gal beta 1-->3(4)GlcNAc)--the disaccharide residue at the nonreducing end of the carbohydrate chains derived from either N- or O-glycosidic linkage--Ricinus communis agglutinin (RCA1), Datura stramonium (TAL, Thorn apple), Erythrina cristagalli (ECL, Coral tree), and Geodia cydonium (GCL). (6) B (Gal alpha 1-->3Gal), human blood group B specific disaccharide--Griffonia(Banderiaea) simplicifolia B4 (GSI-B4). (7) E (Gal alpha 1-->4Gal), receptors for pathogenic E

  13. PURIFICATION AND CHARACTERIZATION OF A NEW MANNOSE-SPECIFIC LECTIN FROM Hyacinthella аcutiloba K. Perss.

    Directory of Open Access Journals (Sweden)

    V. O. Antonyuk

    2013-06-01

    Full Text Available A new lectin with 6.5 mg/kg yield was purified from fresh bulb Hyacinthella аcutiloba K. Perss. by combination of affinity chromathography on yeast mannan and by ion exchange chromatography on DEAE-toyopearl. The best lectin inhibitor among tested mono- and disaccharides was D-turanose (Glcp ?1-3 Fruf. Very powerful inhibitor of lectin activity was yeast mannan. The lectin revealed weak affinity to ?-methyl-Dmannoside, D-fructose and 2-acetamido-D-galactopyranoside. The lectin interacted also with pig liver glycogen, starch and mannose-containing glycoproteins (ovoalbumin, ovomucoid and calf thyroglobulin, but don’t interacted with horsera dish peroxidase and calf intestine alkaline phosphatase. According to electrophoresis, in 20% SDS-PAAG containing SDS-Na the lectin consists with subunits of molecular weight 12 kDa. Molecular weight of the lectin is 48 kDa according to gelchromatography on Toyopearl HW-55. The lectin agglutinated best of all rabbit erythrocytes and worse agglutinated guinea-pig, very weak — rat erythrocytes and did not agglutinate human and goat erythrocytes. After dialysis against 1% EDTA sodium salt solution the lectin did not lose hemaglutinating activity and endured heating to +65 °C during one hour.

  14. Crystallization and preliminary X-ray diffraction analysis of HML, a lectin from the red marine alga Hypnea musciformis

    Energy Technology Data Exchange (ETDEWEB)

    Nagano, Celso S.; Gallego del Sol, Francisca [Instituto de Biomedicina de Valencia, CSIC, Valencia (Spain); Cavada, Benildo S.; Nascimento, Kyria Santiago Do [Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, CE 60451-970 (Brazil); Nunes, Eudismar Vale; Sampaio, Alexandre H. [Laboratorio de Bioquímica Marinha, Departamento de Engenharia de Pesca, Universidade Federal do Ceará, Fortaleza, CE 60451-970 (Brazil); Calvete, Juan J., E-mail: jcalvete@ibv.csic.es [Instituto de Biomedicina de Valencia, CSIC, Valencia (Spain)

    2005-11-01

    The crystallization and preliminary X-ray diffraction analysis of a red marine alga lectin isolated from H. musciformis is reported. HML, a lectin from the red marine alga Hypnea musciformis, defines a novel lectin family. Orthorhombic crystals of HML belonging to space group P2{sub 1}2{sub 1}2{sub 1} grew within three weeks at 293 K using the hanging-drop vapour-diffusion method. A complete data set was collected at 2.4 Å resolution. HML is the first marine alga lectin to be crystallized.

  15. Surface plasmon resonance for real-time study of lectin-carbohydrate interactions for the differentiation and identification of glycoproteins.

    Science.gov (United States)

    Safina, Gulnara; Duran, Iu Benet; Alasel, Mohammed; Danielsson, Bengt

    2011-06-15

    A study of specific interactions between lectins and glycoproteins has been carried out using surface plasmon resonance (SPR) in a flow-injection mode. Lectins were covalently immobilised on the surfaces of the microfluidic sensor chip via amine coupling and serum glycoproteins were injected into the flow channels. Specific lectin-glycoprotein interactions caused the shift of refractive index proportional to the mass concentration accumulated on the channel surface. Lectins showed different affinity to the tested glycoproteins and each glycoprotein displayed its own lectin-binding pattern. It is possible to distinguish and identify even glycoproteins with similar sugar structures by simple and quick screening. The working conditions of the assay were optimised. The lectin-based SPR made it possible to carry out the label-free detection of glycoproteins within a broad concentration range with a good linearity. Regeneration conditions for the surface of the sensor chip were found and optimised. Combination of 10mM HCl and 10mM glycine-HCl (pH 2.5) removes the bound glycoproteins from the lectin surface without damaging it. The kinetic and affinity parameters of lectin-glycoprotein binding were evaluated. The proposed method was tested on human glycosylated serum. Combination of the lectin panel with SPR is suitable both for specific screening and for sensitive assay of serum glycoproteins.

  16. Purification and characterization of a mucin specific mycelial lectin from Aspergillus gorakhpurensis: application for mitogenic and antimicrobial activity.

    Directory of Open Access Journals (Sweden)

    Ram Sarup Singh

    Full Text Available BACKGROUND: Lectins are carbohydrate binding proteins or glycoproteins that bind reversibly to specific carbohydrates present on the apposing cells, which are responsible for their ability to agglutinate red blood cells, lymphocytes, fibroblasts, etc. Interest in lectins has been intensified due to their carbohydrate specificity as they can be valuable reagents for the investigation of cell surface sugars, purification and characterization of glycoproteins. The present study reports the purification, characterization and evaluation of mitogenic and antimicrobial potential of a mycelial lectin from Aspergillus gorakhpurensis. METHODS: Affinity chromatography on mucin-sepharose column was carried out for purification of Aspergillus gorakhpurensis lectin. The lectin was characterized for physico-chemical parameters. Mitogenic potential of the lectin was evaluated against splenocytes of Swiss albino mice by MTT assay. Antimicrobial activity of the purified lectin has also been evaluated by disc diffusion assay. RESULTS: Single-step affinity purification resulted in 18.6-fold purification of the mycelial lectin. The molecular mass of the lectin was found to be 70 kDa and it was composed of two subunits of 34.8 kDa as determined by gel filtration chromatography, SDS-PAGE and MALDI-TOF analysis. pH optima of the lectin was found to be 6.5-9.5, while optimum temperature for lectin activity was 20-30 °C. Lectin was stable within a pH range of 7.0-10.5 and showed fair thermostability. EDTA did not affect lectin activity whereas it was found susceptible to the denaturants tested. MTT assay revealed strong mitogenic potential of A. gorakhpurensis lectin at a concentration upto 150 µg/mL. Antimicrobial activity assay showed its potent antibacterial activity against Bacillus cereus, Staphylococcous aureus and Escherichia coli and marginal antifungal activity against Saccharomyces cerevisiae. CONCLUSION: This is the first report on the mitogenic and

  17. A-current modifies the spike of C-type neurones in the rabbit nodose ganglion.

    Science.gov (United States)

    Ducreux, C; Puizillout, J J

    1995-07-15

    1. In the rabbit nodose ganglion, C-type fibre neurones (C neurones) can be divided into two subtypes according to their after-hyperpolarizing potential (AHP) i.e. those with a fast AHP only and those with a fast AHP and a subsequent slow AHP produced by a slow calcium-dependent potassium current. In addition we have shown that some C neurones can be divided into two groups according to the effect of membrane hyperpolarization on their spikes i.e. type 1 in which duration and amplitude do not change and type 2 in which duration and amplitude decrease significantly. 2. In the present report we studied the effect of A-current (IA) on spike duration, amplitude and slow AHP using intracellular recording techniques. 3. To detect the presence of IA, we first applied a series of increasing rectangular hyperpolarizing pulses to remove IA inactivation and then a short depolarizing pulse to trigger a spike. In type 1 C neurones the lag time of the spike in relation to hyperpolarization remains constant whereas in type 2 C neurones the spike only appears after IA inactivation and lag time in relation to hyperpolarization is lengthened. Thus, type 2 C neurones have an IA while type 1 C neurones do not. The fact that addition of cadmium did not change the lag time in type 2 C neurones shows that the IA is not calcium dependent. 4. Nodose neurones can be orthodromically activated by stimulation of the vagal peripheral process. In this way, after a hyperpolarizing pulse, IA can be fully activated by the orthodromic spike itself. Under these conditions it is possible to analyse the effects of IA on the spike. This was done by increasing either the hyperpolarizing potential, pulse duration, or the delay of the spike after the end of the pulse. We observed that maximum IA inactivation removal was always associated with the lowest duration and amplitude of the spike. 5. When IA inhibitors, 4-aminopyridine (4-AP) or catechol, were applied to type 2 C neurones, the delay of the spike

  18. L-Rhamnose-binding lectins (RBLs) in channel catfish, Ictalurus punctatus: Characterization and expression profiling in mucosal tissues.

    Science.gov (United States)

    Thongda, Wilawan; Li, Chao; Luo, Yupeng; Beck, Benjamin H; Peatman, Eric

    2014-06-01

    Rhamnose-binding lectins (RBLs) have recently emerged as important molecules in the context of innate immunity in teleost fishes. Previously, using RNA-seq technology, we observed marked up-regulation of a RBL in channel catfish (Ictalurus punctatus) gill following a challenge with the bacterial pathogen Flavobacterium columnare. Furthermore, the magnitude of RBL up-regulation positively correlated with disease susceptibility. Moving forward from these findings, we wished to more broadly understand RBL function, diversity, and expression kinetics in channel catfish. Therefore, in the present study we characterized the RBL gene family present in select channel catfish tissues and profiled family member expression after challenge with two different Gram-negative bacterial pathogens. Here, six RBLs were identified from channel catfish and were designated IpRBL1a, IpRBL1b, IpRBL1c, IpRBL3a, IpRBL3b, and IpRBL5a. These RBLs contained carbohydrate recognition domains (CRD) ranging from one to three domains and each CRD contained the conserved motifs of -YGR- and -DPC-. Despite a level of structural conservation, the catfish RBLs showed low full-length identity with RBLs from outside the order Siluriformes. IpRBL expression after bacterial infection varied depending on both pathogen and tissue type, suggesting that IpRBLs may exert disparate functions or exhibit distinct tissue-selective roles in the host immune response to bacterial pathogens.

  19. Allosteric role of the large-scale domain opening in biological catch-binding

    Science.gov (United States)

    Pereverzev, Yuriy V.; Prezhdo, Oleg V.; Sokurenko, Evgeni V.

    2009-05-01

    The proposed model demonstrates the allosteric role of the two-domain region of the receptor protein in the increased lifetimes of biological receptor/ligand bonds subjected to an external force. The interaction between the domains is represented by a bounded potential, containing two minima corresponding to the attached and separated conformations of the two protein domains. The dissociative potential with a single minimum describing receptor/ligand binding fluctuates between deep and shallow states, depending on whether the domains are attached or separated. A number of valuable analytic expressions are derived and are used to interpret experimental data for two catch bonds. The P-selectin/P-selectin-glycoprotein-ligand-1 (PSGL-1) bond is controlled by the interface between the epidermal growth factor (EGF) and lectin domains of P-selectin, and the type 1 fimbrial adhesive protein (FimH)/mannose bond is governed by the interface between the lectin and pilin domains of FimH. Catch-binding occurs in these systems when the external force stretches the receptor proteins and increases the interdomain distance. The allosteric effect is supported by independent measurements, in which the domains are kept separated by attachment of another ligand. The proposed model accurately describes the experimentally observed anomalous behavior of the lifetimes of the P-selectin/PSGL-1 and FimH/mannose complexes as a function of applied force and provides valuable insights into the mechanism of catch-binding.

  20. Activation of dendritic cells by the Gal-lectin of Entamoeba histolytica drives Th1 responses in vitro and in vivo.

    Science.gov (United States)

    Ivory, Catherine P A; Chadee, Kris

    2007-02-01

    Amebiasis is a human disease caused by the protozoan intestinal parasite Entamoeba histolytica. Vaccine development has focused on the parasite's surface galactose-N-acetyl-D-galactosamine inhibitable lectin (Gal-lectin) as a protective antigen. The Gal-lectin is immunogenic and has been shown to induce Th1 cytokines in vitro and in vivo. The immunological basis of the protective immune response elicited by the Gal-lectin is unknown. In this study, we investigated the response of BALB/c bone marrow-derived DC to E. histolytica Gal-lectin. Incubation of immature DC with Gal-lectin resulted in activation and maturation after 24 h. FACS analysis demonstrated an up-regulation of DC maturation markers CD80, CD86, CD40 and MHC class II upon exposure to Gal-lectin. The Gal-lectin also induced DC production of IL-12, indicating a Th1 response. Gal-lectin-activated DC were able to stimulate T cell proliferation in an allogeneic mixed leukocyte reaction and adoptive transfer of Gal-lectin-treated DC into naïve mice resulted in IFN-gamma-producing Gal-lectin-sensitized T cells. The activation of DC by Gal-lectin was mediated by MAPK and NF-kappaB. These findings indicate that E. histolytica Gal-lectin is a potent vaccine antigen capable of directly initiating DC maturation and activation characterized by Th1 cytokine production.

  1. Diagnosis of myocardial infarction based on lectin-induced erythrocyte agglutination: a feasibility study

    Science.gov (United States)

    Bocsi, József; Nieschke, Kathleen; Mittag, Anja; Reichert, Thomas; Laffers, Wiebke; Marecka, Monika; Pierzchalski, Arkadiusz; Piltz, Joachim; Esche, Hans-Jürgen; Wolf, Günther; Dähnert, Ingo; Baumgartner, Adolf; Tarnok, Attila

    2014-03-01

    Myocardial infarction (MI) is an acute life-threatening disease with a high incidence worldwide. Aim of this study was to test lectin-carbohydrate binding-induced red blood cell (RBC) agglutination as an innovative tool for fast, precise and cost effective diagnosis of MI. Five lectins (Ricinus communis agglutinin (RCA), Phaseolus vulgaris erythroagglutinin (PHA), Datura stramonium agglutinin (DSA), Artocarpus agglutinin (ArA), Triticum agglutinin (TA)) were tested for ability to differentiate between agglutination characteristics in patients with MI (n = 101) or angina pectoris without MI (AP) (n = 34) and healthy volunteers (HV) as control (n =68) . RBC agglutination was analyzed by light absorbance of a stirred RBC suspension in the green to red light spectrum in an agglutimeter (amtec, Leipzig, Germany) for 15 min after lectin addition. Mean cell count in aggregates was estimated from light absorbance by a mathematical model. Each lectin induced RBC agglutination. RCA led to the strongest RBC agglutination (~500 RBCs/aggregate), while the others induced substantially slower agglutination and lead to smaller aggregate sizes (5-150 RBCs/aggregate). For all analyzed lectins the lectin-induced RBC agglutination of MI or AP patients was generally higher than for HV. However, only PHA induced agglutination that clearly distinguished MI from HV. Variance analysis showed that aggregate size after 15 min. agglutination induced by PHA was significantly higher in the MI group (143 RBCs/ aggregate) than in the HV (29 RBC-s/aggregate, p = 0.000). We hypothesize that pathological changes during MI induce modification of the carbohydrate composition on the RBC membrane and thus modify RBC agglutination. Occurrence of carbohydrate-lectin binding sites on RBC membranes provides evidence about MI. Due to significant difference in the rate of agglutination between MI > HV the differentiation between these groups is possible based on PHA-induced RBC-agglutination. This novel assay

  2. Lectin binding patterns and carbohydrate mediation of sperm binding to llama oviductal cells in vitro.

    Science.gov (United States)

    Apichela, Silvana A; Valz-Gianinet, Jorge N; Schuster, Stefanie; Jiménez-Díaz, María A; Roldán-Olarte, Eugenia M; Miceli, Dora C

    2010-04-01

    Sperm binding to oviductal epithelium would be involved in sperm reservoir formation in the utero tubal junction (UTJ). Although in other mammals sperm-oviduct interaction has been proved to be mediated by carbohydrate-recognition mechanisms, the factors implicated in the sperm adhesion to oviductal epithelium of llama are still unknown. In order to assess the role of carbohydrates present in the mucosa surface, we examined the distribution of glycoconjugates in the llama oviduct by confocal lectin-histochemistry. Mannosyl, glucosyl, N-acetylglucosaminyl, galactosyl, N-acetylgalactosaminyl and sialic acid residues were detected in the oviductal mucose glycocalyx. By incubation of UTJ oviductal explants with LCA, DBA, UEA-1 or PNA lectin previous to co-culture with sperm, we observed a significant decrease in sperm binding only with LCA lectin. In the mucosa surface there were numerous d-glucosyl and D-manosyl residues, which were spotted by this lectin. Probably, this fact promotes the whole covering of the oviduct luminal surface by the sugar-lectin complex, preventing sperm access and adhesion of further residues. However, sperm incubation with mannose or glucose does not significantly prevent binding, which means that glucose and mannose would not be involved in a specific sperm-oviduct interaction. On the other hand, we observed a high reduction in sperm binding to UTJ explants with N-acetylgalactosamine and galactose (pllama sperm have lectin-like molecules in their surface, as is the case in other mammals. Probably, these lectin-like molecules, by means of N-acetylgalactosamine and galactose recognition, could link the sperm to the oviductal mucosa with the purpose of forming storing sites in the UTJ. Our results support the idea that more than one carbohydrate could participate in sperm reservoir formation in the llama UTJ oviductal segment.

  3. Binding of the blood group-reactive lectins to human adult kidney specimens.

    Science.gov (United States)

    Laitinen, L; Juusela, H; Virtanen, I

    1990-01-01

    The binding of a panel of blood group-reactive lectins to frozen sections of human kidney was studied with a special emphasis on reactivity with endothelia and basement membranes. The blood group A-reactive lectins, all specific for alpha-D-N-acetylgalactosamine (GalNAc), Helix aspersa (HAA), Helix pomatia (HPA), and Griffonia simplicifolia I-A4 (GSA-I-A4) agglutinins bound to the endothelium in specimens with blood groups A and AB. In other samples, these lectins reacted predominantly with tubular basement membranes, as well as with certain tubules. Both Dolichos biflorus (DBA) and Vicia villosa agglutinins (VVA), reported to react with blood group A1 substance, failed to reveal endothelia in most specimens, but bound differently to tubules in all blood groups. The blood group B-reactive lectins, specific for alpha-D-galactose (alpha-Gal) or GalNAc, respectively, GSA-I-B4 and Sophora japonica agglutinin (SJA), bound to the endothelia in specimens from blood group B or AB and in other specimens bound only to certain tubules. Among the blood group O-reactive lectins, specific for alpha-L-fucose (Fuc), Ulex europaeus I agglutinin (UEA-I) conjugates, but not other lectins with a similar nominal specificity, bound strongly to endothelia in specimens with blood group O. The UEA-I conjugates bound distinctly more faintly to endothelia in specimens of other blood groups. The present results indicate that lectins, binding to defined blood group determinants, react with endothelia in specimens of the respective blood group status. Furthermore, they suggest that basement membranes and some tubules in the human kidney show a distinct heterogeneity in their expression of saccharide residues, related to their blood group status.

  4. A glucuronic acid binding leguminous lectin with mitogenic activity toward mouse splenocytes.

    Science.gov (United States)

    Chan, Yau Sang; Wong, Jack Ho; Ng, Tzi Bun

    2011-02-01

    A dimeric 64-kDa lectin was purified from seeds of French bean (Phaseolus vulgaris) cultivar number 1. The purification protocol entailed Q-Sepharose, Affi-gel blue gel, Mono S and Superdex 75. The lectin-enriched fraction was adsorbed on Q-Sepharose and Affi-gel blue gel and desorbed using 1M NaCl in the starting buffer. Hemagglutinating activity was adsorbed on Mono S and eluted with a linear 0.3-1 M NaCl gradient. Gel filtration on Superdex 75 yielded a single absorbance peak which appeared as a single 32-kDa in sodium dodecyl sulfate poylacylamide gel electrophoresis. Full hemagglutinating activity was observed when the lectin was exposed to a pH ranging from 3 to 11. About 50% activity remained at pH 12, and about 25% at pH 0 to pH 2. Activity was totally abolished at pH 13-14. The activity was completely preserved when the ambient temperature was 20 °C-60 °C. However, only 50% and 12.5% of the activity remained at 65 °C and 70 °C, respectively. Activity was barely discernible at 75 °C and completely abrogated at and above 80 °C. Hemagglutinating activity of the lectin was inhibited by glucuronic acid. Maximum mitogenic activity of the lectin toward murine splenocytes occurred at a lectin concentration of 0.488 µM. The mitogenic activity was nearly eliminated in the presence of 250 mM glucuronic acid. The lectin did not exhibit antiproliferative activity toward hepatoma (HepG2) cells, breast cancer (MCF7) cells, and nasopharynegeal carcinoma CNE stage 1 and stage 2 cells. It was also devoid of significant anti-HIV reverse transcriptase activity.

  5. Borrelia burgdorferi RST1 (OspC type A) genotype is associated with greater inflammation and more severe Lyme disease.

    Science.gov (United States)

    Strle, Klemen; Jones, Kathryn L; Drouin, Elise E; Li, Xin; Steere, Allen C

    2011-06-01

    Evidence is emerging for differential pathogenicity among Borrelia burgdorferi genotypes in the United States. By using two linked genotyping systems, ribosomal RNA intergenic spacer type (RST) and outer surface protein C (OspC), we studied the inflammatory potential of B. burgdorferi genotypes in cells and patients with erythema migrans or Lyme arthritis. When macrophages were stimulated with 10 isolates of each RST1, RST2, or RST3 strain, RST1 (OspC type A)-stimulated cells expressed significantly higher levels of IL-6, IL-8, chemokine ligand (CCL) 3, CCL4, tumor necrosis factor, and IL-1β, factors associated with innate immune responses. In peripheral blood mononuclear cells, RST1 strains again stimulated significantly higher levels of these mediators. Moreover, compared with RST2, RST1 isolates induced significantly more interferon (IFN)-α, IFN-γ, and CXCL10, which are needed for adaptive immune responses; however, OspC type I (RST3) approached RST1 (OspC type A) in stimulating these adaptive immune mediators. Similarly, serum samples from patients with erythema migrans who were infected with the RST1 genotype had significantly higher levels of almost all of these mediators, including exceptionally high levels of IFN-γ-inducible chemokines, CCL2, CXCL9, and CXCL10; and this pronounced inflammatory response was associated with more symptomatic infection. Differences among genotypes were not as great in patients with Lyme arthritis, but those infected with RST1 strains more often had antibiotic-refractory arthritis. Thus, the B. burgdorferi RST1 (OspC type A) genotype, followed by the RST3 (OspC type I) genotype, causes greater inflammation and more severe disease, establishing a link between spirochetal virulence and host inflammation.

  6. Electron microscopic demonstration of lectin binding sites in the taste buds of the European catfish Silurus glanis (Teleostei).

    Science.gov (United States)

    Witt, M; Reutter, K

    1990-01-01

    Taste buds in the European catfish Silurus glanis were examined with electron microscopic lectin histochemistry. For detection of carbohydrate residues in sensory cells and adjacent epithelial cells, gold-, ferritin- and biotin-labeled lectins were used. A post-embedding procedure carried out on tissue sections embedded in LR-White was applied to differentiate between the sensory cells: The lectins from Helix pomatia (HPA) and Triticum vulgare (WGA) bound to N-acetyl-galactosamine and to N-acetylglucosamine residues occurring especially in vesicles of dark sensory cells. This indicates a secretory function of these cells. Most light sensory cells--with some exceptions, probably immature cells--, are HPA-negative. The mucus of the receptor field and at the top of the adjacent epithelial cells was strongly HPA-positive. Pre-embedding studies were performed in order to obtain information about the reaction of the mucus with lectins under supravital conditions. The mucus of the taste bud receptor field exhibited intensive binding to WGA, but not to the other lectins tested. Most lectins bound predominantly to the surface mucus of the nonsensory epithelium and to the marginal cells close to the receptor field. The strong lectin binding to mucins and the relatively weak lectin binding to cell surface membranes in pre-embedding studies suggest that the mucus possibly serves as a barrier which is passed selectively only by a small amount of lectins or lectin-carbohydrate complexes. Lectin-carbohydrate interactions may play a role in recognition phenomena on the plasmalemmata of the taste bud sensory cells. Recognition processes directed to bacteria or viruses should be considered as well.

  7. A lectin with highly potent inhibitory activity toward breast cancer cells from edible tubers of Dioscorea opposita cv. nagaimo.

    Directory of Open Access Journals (Sweden)

    Yau Sang Chan

    Full Text Available A 70-kDa galactose-specific lectin was purified from the tubers of Dioscorea opposita cv. nagaimo. The purification involved three chromatographic steps: anion exchange chromatography on a Q-Sepharose column, FPLC-anion exchange chromatography on a Mono Q column, and FPLC-gel filtration on a Superdex 75 column. The purified nagaimo lectin presented as a single 35-kDa band in reducing SDS-PAGE while it exhibited a 70-kDa single band in non-reducing SDS-PAGE suggesting its dimeric nature. Nagaimo lectin displayed moderate thermostability, retaining full hemagglutinating activity after heating up to 62°C for 30 minutes. It also manifested stability over a wide pH range from pH 2 to 13. Nagaimo lectin was a galactose-specific lectin, as evidenced by binding with galactose and galactose-containing sugars such as lactose and raffinose. The minimum concentration of galactose, lactose and raffinose required to exert an inhibitory effect on hemagglutinating activity of nagaimo lectin was 20 mM, 5 mM and 40 mM, respectively. Nagaimo lectin inhibited the growth of some cancer cell lines including breast cancer MCF7 cells, hepatoma HepG2 cells and nasopharyngeal carcinoma CNE2 cells, with IC(50 values of 3.71 µM, 7.12 µM and 19.79 µM, respectively, after 24 hour treatment with nagaimo lectin. The induction of phosphatidylserine externalization and mitochondrial depolarization indicated that nagaimo lectin evoked apoptosis in MCF7 cells. However, the anti-proliferative activity of nagaimo lectin was not blocked by application of galactose, signifying that the activity was not related to the carbohydrate binding specificity of the lectin.

  8. Binding studies of alpha-GalNAc-specific lectins to the alpha-GalNAc (Tn-antigen) form of porcine submaxillary mucin and its smaller fragments.

    Science.gov (United States)

    Dam, Tarun K; Gerken, Thomas A; Cavada, Benildo S; Nascimento, Kyria S; Moura, Tales R; Brewer, C Fred

    2007-09-21

    Isothermal titration microcalorimetry (ITC) and hemagglutination inhibition measurements demonstrate that a chemically and enzymatically prepared form of porcine submaxillary mucin that possesses a molecular mass of approximately 10(6) daltons and approximately 2300 alpha-GalNAc residues (Tn-PSM) binds to the soybean agglutinin (SBA) with a K(d) of 0.2 nm, which is approximately 10(6)-fold enhanced affinity relative to GalNAcalpha1-O-Ser (Tn), the pancarcinoma carbohydrate antigen. The enzymatically derived 81 amino acid tandem repeat domain of Tn-PSM containing approximately 23 alpha-GalNAc residues binds with approximately 10(3)-fold enhanced affinity, while the enzymatically derived 38/40 amino acid cleavage product(s) of Tn-PSM containing approximately 11-12 alpha-GalNAc residues shows approximately 10(2)-fold enhanced affinity. A natural carbohydrate decorated form of PSM (Fd-PSM) containing 40% of the core 1 blood group type A tetrasaccharide, and 58% peptide-linked GalNAcalpha1-O-Ser/Thr residues, with 45% of the peptide-linked alpha-GalNAc residues linked alpha-(2,6) to N-glycolylneuraminic acid, shows approximately 10(4) enhanced affinity for SBA. Vatairea macrocarpa lectin (VML), which is also a GalNAc binding lectin, displays a similar pattern of binding to the four forms of PSM, although there are quantitative differences in its affinities as compared with SBA. The higher affinities of SBA and VML for Tn-PSM relative to Fd-PSM indicate the importance of carbohydrate composition and epitope density of mucins on their affinities for lectins. The higher affinities of SBA and VML for Tn-PSM relative to its two shorter chain analogs demonstrate that the length of a mucin polypeptide and hence total carbohydrate valence determines the affinities of the three Tn-PSM analogs. The results suggest a binding model in which lectin molecules "bind and jump" from alpha-GalNAc residue to alpha-GalNAc residue along the polypeptide chain of Tn-PSM before dissociating

  9. Entamoeba histolytica: Adhesins and Lectins in the Trophozoite Surface

    Directory of Open Access Journals (Sweden)

    Magdalena Aguirre García

    2015-02-01

    Full Text Available Entamoeba histolytica is the causative agent of amebiasis in humans and is responsible for 100,000 deaths annually, making it the third leading cause of death due to a protozoan parasite. Pathogenesis appears to result from the potent cytotoxic activity of the parasite, which kills host cells within minutes. Although the mechanism is unknown, it is well established to be contact-dependent. The life cycle of the parasite alternates with two forms: the resistant cyst and the invasive trophozoite. The adhesive interactions between the parasite and surface glycoconjugates of host cells, as well as those lining the epithelia, are determinants for invasion of human tissues, for its cytotoxic activity, and finally for the outcome of the disease. In this review we present an overview of the information available on the amebic lectins and adhesins that are responsible of those adhesive interactions and we also refer to their effect on the host immune response. Finally, we present some concluding remarks and perspectives in the field.

  10. Rheologic characterization of vegetal lectins by dissociation of induced erythrocyte agglutinates.

    Science.gov (United States)

    Rasia, R J; Valverde, J R; Gentils, M; Cauchois, C; Stoltz, J F

    1997-01-01

    Energy evolved from hemagglutination reaction or spent in dissociating erythrocyte agglutinates has been proved to be an excellent parameter for analyzing cell-cell interactions mediated by bridging molecules such as antibodies or lectins. We developed a new rheo-optical method to estimate the energy of dissociation of red blood cell agglutinates. In a Couette shear field agglutinates can be dissociated until a suspension of monodispersed cells is obtained. Intensity of light backscattered by suspended agglutinates increases during their mechanical dissociation. Variation of backscattered light intensity correlates with the energy spent in the process. The adhesive energy of erythrocyte agglutination induced by lectins has been estimated by applying this method. Two specific lectins (Dolichus Biflorus agglutinin and Ulex Europaeus agglutinin) and a new lectin obtained from Amarantus Cruentus seeds which specificity is unknown were studied. Results obtained in this work for Dolichus Biflorus lectin are comparable with values published by other authors. An asymptotic decrease of adhesive energy was observed when the mechanical dissociation was applied several times on the same sample. Our results suggest that the cell detachment is accompanied by the extraction of membrane receptors. This finding is consistent with results obtained by other authors.

  11. Purification and molecular cloning of a new galactose-specific lectin from Bauhinia variegata seeds

    Indian Academy of Sciences (India)

    Luciano S Pinto; Celso S Nagano; Taianá M Oliveira; Tales R Moura; Alexandre H Sampaio; Henri Debray; Vicente P Pinto; Odir A Dellagostin; Benildo S Cavada

    2008-09-01

    A new galactose-specific lectin was purified from seeds of a Caesalpinoideae plant, Bauhinia variegata, by affinity chromatography on lactose–agarose. Protein extracts haemagglutinated rabbit and human erythrocytes (native and treated with proteolytic enzymes), showing preference for rabbit blood treated with papain and trypsin. Among various carbohydrates tested, the lectin was best inhibited by D-galactose and its derivatives, especially lactose. SDS-PAGE showed that the lectin, named BVL, has a pattern similar to other lectins isolated from the same genus, Bauhinia purpurea agglutinin (BPA). The molecular mass of BVL subunit is 32 871 Da, determined by MALDI-TOF spectrometry. DNA extracted from B. variegata young leaves and primers designed according to the B. purpurea lectin were used to generate specific fragments which were cloned and sequenced, revealing two distinct isoforms. The bvl gene sequence comprised an open reading frame of 876 base pairs which encodes a protein of 291 amino acids. The protein carried a putative signal peptide. The mature protein was predicted to have 263 amino acid residues and 28 963 Da in size.

  12. Purification and molecular cloning of a new galactose-specific lectin from Bauhinia variegata seeds.

    Science.gov (United States)

    Pinto, Luciano S; Nagano, Celso S; Oliveira, Taianá M; Moura, Tales R; Sampaio, Alexandre H; Debray, Henri; Pinto, Vicente P; Dellagostin, Odir A; Cavada, Benildo S

    2008-09-01

    A new galactose-specific lectin was purified from seeds of a Caesalpinoideae plant, Bauhinia variegata, by affinity chromatography on lactose-agarose. Protein extracts haemagglutinated rabbit and human erythrocytes (native and treated with proteolytic enzymes), showing preference for rabbit blood treated with papain and trypsin. Among various carbohydrates tested, the lectin was best inhibited by D-galactose and its derivatives, especially lactose. SDS-PAGE showed that the lectin, named BVL, has a pattern similar to other lectins isolated from the same genus, Bauhinia purpurea agglutinin (BPA). The molecular mass of BVL subunit is 32 871 Da, determined by MALDI-TOF spectrometry. DNA extracted from B.variegata young leaves and primers designed according to the B. purpurea lectin were used to generate specific fragments which were cloned and sequenced, revealing two distinct isoforms. The bvl gene sequence comprised an open reading frame of 876 base pairs which encodes a protein of 291 amino acids. The protein carried a putative signal peptide. The mature protein was predicted to have 263 amino acid residues and 28 963 Da in size.

  13. Optimized immobilization of lectins using self-assembled monolayers on polysilicon encoded materials for cell tagging.

    Science.gov (United States)

    Penon, Oriol; Siapkas, Dimitrios; Novo, Sergi; Durán, Sara; Oncins, Gerard; Errachid, Abdelhamid; Barrios, Lleonard; Nogués, Carme; Duch, Marta; Plaza, José Antonio; Pérez-García, Lluïsa

    2014-04-01

    Self-assembled monolayers (SAMs) have been used for the preparation of functional microtools consisting of encoded polysilicon barcodes biofunctionalized with proteins of the lectin family. These hybrid microtools exploit the lectins ability for recognizing specific carbohydrates of the cell membrane to give an efficient system for cell tagging. This work describes how the control of the methodology for SAM formation on polysilicon surfaces followed by lectin immobilization has a crucial influence on the microtool biofunction. Several parameters (silanization time, silane molar concentration, type of solvent or deposition methodology) have been studied to establish optimal function. Furthermore, silanes incorporating different terminal groups, such as aldehyde, activated ester or epoxide groups were tested in order to analyze their chemical coupling with the biomolecules, as well as their influence on the biofunctionality of the immobilized protein. Two different lectins - wheat germ agglutinin (WGA) and phytohemagglutinin (PHA-L) - were immobilized, because they have different and specific cell recognition behaviour and exhibit different cell toxicity. In this way we can assess the effect of intrinsic bulk toxicity with that of the cell compatibility once immobilized as well as the importance of cell affinity. A variety of nanometrical techniques were used to characterize the active surfaces, and lectin immobilization was quantified using ultraviolet-visible absorption spectroscopy (UV-vis) and optical waveguide light mode spectroscopy (OWLS). Once the best protocol was found, WGA and PHA were immobilized on polysilicon coded barcodes, and these microtools showed excellent cell tagging on living mouse embryos when WGA was used.

  14. The effect of Cratylia floribunda lectin on renal hemodynamics and ion transport

    Directory of Open Access Journals (Sweden)

    Alexandre Havt

    2015-09-01

    Full Text Available Lectins have been described as glycoproteins that reversibly and specifically bind to carbohydrates. Legume lectins isolated from the subtribe Diocleinae (Canavalia, Dioclea andCratylia are structurally homologous with respect to their primary structures. The Diocleinae lectins of Canavalia brasiliensis, Dioclea guianensis andCanavalia ensiformis have been shown to distinctly alter physiological parameters in isolated rat kidneys. Thus, the aim of this study was to investigate the effect of Cratylia floribunda lectin (CFL on renal hemodynamics and ion transport in rats. In isolated perfused kidneys, CFL (10 mg/mL, n=5 increased RPP, RVR and decreased %TK+, but did not change urinary flow, glomerular filtration rate, sodium or chloride tubular transport. In isolated perfused mesenteric bed, CFL (3 and 10 mg/mL/min; n=4 did not alter tissue basal tonus or tissue contraction by phenylephrine (1 mM/mL/min. In conclusion, the seed lectin of Cratylia floribunda increased renal hemodynamic parameters showing a kaliuretic effect. This effect could be of tubular origin, rather than a result from haemodynamic alterations.

  15. Reverse lectin ELISA for detecting fucosylated forms of α1-acid glycoprotein associated with hepatocellular carcinoma

    Science.gov (United States)

    Stål, Per; Zenlander, Robin; Edenvik, Pia; Alexandersson, Catharina; Haglund, Mats; Rydén, Ingvar; Påhlsson, Peter

    2017-01-01

    Altered fucosylation of glycoproteins is associated with development of hepatocellular carcinoma (HCC). Lectins have been commonly used to assay changes in fucosylation of plasma glycoproteins. In the present study a recombinantly engineered form of the fucose binding lectin Aleuria aurantia (AAL) consisting of a single binding site for fucose (S2), was used to construct a reverse lectin ELISA method. Microtiter plates coated with the S2 lectin were used to capture glycoproteins from plasma samples followed by antibody detection of S2-bound fucosylated α1-acid glycoprotein (S2-bound AGP). The method was used to compare the level of S2-bound AGP in serum samples from a small cohort of patients with hepatitis, cirrhosis or HCC. Using the reverse S2 lectin ELISA it was shown that the levels of S2-bound AGP was significantly higher in HCC patients compared to non-cancer patients and that there was also a significant elevation of S2-bound AGP in HCC patients compared to cirrhosis patients. There was no correlation between the level of S2-bound AGP and total AGP concentration. The performance of S2-bound AGP in differentiating HCC from cirrhosis samples or hepatitis samples were compared to other markers. A combination of S2-bound AGP, α-fetoprotein and AGP concentration showed performances giving area under receiver operating curves of 0.87 and 0.95 respectively. PMID:28296934

  16. Rapid affinity-purification and physicochemical characterization of pumpkin (Cucurbita maxima) phloem exudate lectin.

    Science.gov (United States)

    Narahari, Akkaladevi; Swamy, Musti J

    2010-04-21

    The chito-oligosaccharide-specific lectin from pumpkin (Cucurbita maxima) phloem exudate has been purified to homogeneity by affinity chromatography on chitin. After SDS/PAGE in the presence of 2-mercaptoethanol, the pumpkin phloem lectin yielded a single band corresponding to a molecular mass of 23.7 kDa, whereas ESI-MS (electrospray ionization MS) gave the molecular masses of the subunit as 24645 Da. Analysis of the CD spectrum of the protein indicated that the secondary structure of the lectin consists of 9.7% alpha-helix, 35.8% beta-sheet, 22.5% beta-turn and 32.3% unordered structure. Saccharide binding did not significantly affect the secondary and tertiary structures of the protein. The haemagglutinating activity of pumpkin phloem lectin was mostly unaffected in the temperature range 4-70 degrees C, but a sharp decrease was seen between 75 and 85 degrees C. Differential scanning calorimetric and CD spectroscopic studies suggest that the lectin undergoes a co-operative thermal unfolding process centred at approx. 81.5 degrees C, indicating that it is a relatively stable protein.

  17. Anti-tumor and anti-viral activities of Galanthus nivalis agglutinin (GNA)-related lectins.

    Science.gov (United States)

    Wu, Lei; Bao, Jin-Ku

    2013-04-01

    Galanthus nivalis agglutinin (GNA)-related lectin family, a superfamily of strictly mannose-binding specific lectins widespread among monocotyledonous plants, is well-known to possess a broad range of biological functions such as anti-tumor, anti-viral and anti-fungal activities. Herein, we mainly focused on exploring the precise molecular mechanisms by which GNA-related lectins induce cancer cell apoptotic and autophagic death targeting mitochondria-mediated ROS-p38-p53 apoptotic or autophagic pathway, Ras-Raf and PI3K-Akt anti-apoptotic or anti-autophagic pathways. In addition, we further discussed the molecular mechanisms of GNA-related lectins exerting anti-viral activities by blocking the entry of the virus into its target cells, preventing transmission of the virus as well as forcing virus to delete glycan in its envelope protein and triggering neutralizing antibody. In conclusion, these findings may provide a new perspective of GNA-related lectins as potential drugs for cancer and virus therapeutics in the future.

  18. Mannose-binding lectin (MBL2) and ficolin-2 (FCN2) polymorphisms in patients on peritoneal dialysis with staphylococcal peritonitis

    NARCIS (Netherlands)

    Meijvis, Sabine C. A.; Herpers, Bjorn L.; Endeman, Henrik; de Jong, Ben; van Hannen, Erik; van Velzen-Blad, Heleen; Krediet, Raymond T.; Struijk, Dirk G.; Biesma, Douwe H.; Bos, Willem Jan W.

    2011-01-01

    Background. Mannose-binding lectin (MBL) and ficolin-2 (FCN) are activators of the lectin pathway of complement and act as primary defences against infection. Single-nucleotide polymorphisms (SNPs) in the MBL2 and FCN2 genes influence the functionality of the proteins. Both proteins are capable of b

  19. Extreme High Prevalence of a Defective Mannose-Binding Lectin (MBL2) Genotype in Native South American West Andean Populations

    DEFF Research Database (Denmark)

    Sandoval, José Raul; Madsen, Hans O; De Stefano, Gianfranco;

    2014-01-01

    Mannose-binding lectin (MBL) is one of the five recognition molecules in the lectin complement pathway. Common variant alleles in the promoter and structural regions of the human MBL gene (MBL2) influence the stability and serum concentration of the protein. Epidemiological studies have shown tha...

  20. Safety testing of GM-rice expressing PHA-E lectin using a new animal test design

    DEFF Research Database (Denmark)

    Poulsen, Morten; Schrøder, Malene; Wilcks, Andrea

    2007-01-01

    The 90-day animal study is the core study for the safety assessment of genetically modified foods in the SAFOTEST project. The model compound tested in the 90-day study was a rice variety expressing the kidney bean Phaseolus vulgaris lectin agglutinin E-form (PHA-E lectin). Female Wistar rats were...... safety testing of genetically modified foods....

  1. Serum mannan-binding lectin-associated serine protease 2 levels in colorectal cancer: relation to recurrence and mortality

    DEFF Research Database (Denmark)

    Ytting, Henriette; Christensen, Ib Jarle; Thiel, Steffen;

    2005-01-01

    PURPOSE: Mannan-binding lectin-associated serine protease 2 (MASP-2) is a plasma protein involved in inflammatory processes. MASP-2 circulates in complex with the protein mannan-binding lectin (MBL) or ficolins, and is activated to recruit the complement system when MBL binds to its targets...

  2. Effect of Algae and Plant Lectins on Planktonic Growth and Biofilm Formation in Clinically Relevant Bacteria and Yeasts

    Science.gov (United States)

    Vasconcelos, Mayron Alves; Arruda, Francisco Vassiliepe Sousa; Carneiro, Victor Alves; Silva, Helton Colares; Nascimento, Kyria Santiago; Sampaio, Alexandre Holanda; Cavada, Benildo; Teixeira, Edson Holanda; Henriques, Mariana

    2014-01-01

    This study aimed to evaluate the abilities of plant and algae lectins to inhibit planktonic growth and biofilm formation in bacteria and yeasts. Initially, ten lectins were tested on Staphylococcus epidermidis, Staphylococcus aureus, Klebsiella oxytoca, Pseudomonas aeruginosa, Candida albicans, and C. tropicalis at concentrations of 31.25 to 250 μg/mL. The lectins from Cratylia floribunda (CFL), Vatairea macrocarpa (VML), Bauhinia bauhinioides (BBL), Bryothamnion seaforthii (BSL), and Hypnea musciformis (HML) showed activities against at least one microorganism. Biofilm formation in the presence of the lectins was also evaluated; after 24 h of incubation with the lectins, the biofilms were analyzed by quantifying the biomass (by crystal violet staining) and by enumerating the viable cells (colony-forming units). The lectins reduced the biofilm biomass and/or the number of viable cells to differing degrees depending on the microorganism tested, demonstrating the different characteristics of the lectins. These findings indicate that the lectins tested in this study may be natural alternative antimicrobial agents; however, further studies are required to better elucidate the functional use of these proteins. PMID:24982871

  3. A Glucosamine-Specific Lectin from Green Dragon No. 8 Beans (Phaseolus vulgaris Induced Apoptosis on Nasopharyngeal Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Yau Sang Chan

    2015-01-01

    Full Text Available A lectin exhibiting antiproliferative activity on tumor cell lines but devoid of antifungal activity has been purified from Phaseolus vulgaris cv. Green Dragon no. 8 seeds. The lectin was a 60 kDa dimeric protein with two 30 kDa subunits. It was a glucosamine-specific lectin as implied from the inhibitory effect of glucosamine on hemagglutinating activity of the lectin. The steps for isolation of the lectin involved Affi-gel blue gel (affinity gel, Mono Q (anion exchanger, and Superdex 75 column (size exclusion. The lectin was purified 20.8-fold from the crude extract of the beans. The purified lectin showed antiproliferative activity on breast cancer MCF7 cell line and nasopharyngeal cancer HONE1 and CNE2 cell lines, but a low activity on normal skin fibroblast HSF98 cell line. The lectin was shown to induce apoptosis on HONE1 cells, as indicated by increased phosphatidylserine externalization and mitochondrial depolarization. It also blocked HONE1 cell division and kept the cells at the G2/M phase of the cell cycle.

  4. A Glucosamine-Specific Lectin from Green Dragon No. 8 Beans (Phaseolus vulgaris) Induced Apoptosis on Nasopharyngeal Carcinoma Cells.

    Science.gov (United States)

    Chan, Yau Sang; Xia, Lixin; Ng, Tzi Bun

    2015-01-01

    A lectin exhibiting antiproliferative activity on tumor cell lines but devoid of antifungal activity has been purified from Phaseolus vulgaris cv. Green Dragon no. 8 seeds. The lectin was a 60 kDa dimeric protein with two 30 kDa subunits. It was a glucosamine-specific lectin as implied from the inhibitory effect of glucosamine on hemagglutinating activity of the lectin. The steps for isolation of the lectin involved Affi-gel blue gel (affinity gel), Mono Q (anion exchanger), and Superdex 75 column (size exclusion). The lectin was purified 20.8-fold from the crude extract of the beans. The purified lectin showed antiproliferative activity on breast cancer MCF7 cell line and nasopharyngeal cancer HONE1 and CNE2 cell lines, but a low activity on normal skin fibroblast HSF98 cell line. The lectin was shown to induce apoptosis on HONE1 cells, as indicated by increased phosphatidylserine externalization and mitochondrial depolarization. It also blocked HONE1 cell division and kept the cells at the G2/M phase of the cell cycle.

  5. Phenotype-associated lectin-binding profiles of normal and transformed blood cells: a comparative analysis of mannose- and galactose-binding lectins from plants and human serum/placenta.

    Science.gov (United States)

    Mann, K K; André, S; Gabius, H J; Sharp, J G

    1994-10-01

    Surface glycoconjugates of normal and transformed blood cells are commonly characterized by plant lectins. To infer physiological significance of protein-carbohydrate interactions, mammalian lectins are obviously preferable as research tools. So far, human serum lectins have not been used to assess their binding to immunophenotyped human normal or transformed blood cells. Thus, our study combines two groups of lectins with different specificity from plant and human sources. Besides concanavalin A (ConA) we have isolated the mannose-binding protein and serum amyloid P component from human serum. Especially the mannose-binding protein is believed to play a role in host defence against bacteria and yeast cells with unknown impact on normal and tumor cells. These three lectins establish the first group. In addition to the immunomodulatory mistletoe lectin, whose binding can elicit enhanced cytokine secretion from mononuclear blood cells, we included the beta-galactoside-binding lectin (14 kDa) from human placenta in the second group. The initial series of measurements was undertaken using two-color flow cytometry to determine the phenotype-associated binding (based on cluster designation; CD) of the lectins to blood and bone marrow cells from normal donors and the cell line CEM (T-lymphoblastoid), KG1-A (primitive myeloid leukemia) and Croco II (B-lymphoblastoid). Heterogeneity was apparent for each lectin in the CD-defined cell populations. Significant differences in binding were noted between Viscum album agglutinin (VAA) and other lectins for CD4+ cells from blood and between mannose-binding protein (MBP) and VAA versus 14 kDa, ConA and serum amyloid P component (SAP) for CD19+ cells from bone marrow.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. The lectin-gold technique: an overview of applications to pathological problems.

    Science.gov (United States)

    Versura, P; Maltarello, M C; Bonvicini, F; Laschi, R

    1989-06-01

    Lectins are proteins, mainly of vegetal origin, which recognize glycosidic residues with high specificity; for this property they have been used for many studies of molecular biology. The colloidal gold represents at present the most popular electron dense marker employed in immunocytochemistry, since it offers intrinsic and unique characteristics which are superior to those displayed by the other markers. The cytochemical method which utilizes the gold-labelled lectins takes advantages from both the two systems, in order to optimize the localization of the glycoconjugates. The present paper reviews both the technical aspects of the preparation of the lectin-gold complex and its application to some selected pathological problems. In particular, the papers concerning the eye and ear tissues, the urinary, reproductive, nervous and digestive systems and the blood cells are quoted.

  7. Epidemiology of chronic wound patients and relation to serum levels of mannan-binding lectin

    DEFF Research Database (Denmark)

    Bitsch, Mikael; Laursen, Inga; Engel, Anne-Mari

    2009-01-01

    The aim of this study was to describe the epidemiology of chronic wounds in a large cohort of patients from a tertiary hospital out-patient clinic, and examine the significance of serum mannan-binding lectin for the occurrence and clinical presentation of such wounds. The study comprised 489......), arterial ulcers (109), and vasculitis (33). The mannan-binding lectin levels of patients with venous leg ulcer, alone or in combination with other types of wounds, differed significantly from the control group, and the frequency of values ... patients the frequency of values >or= 3000 ng/ml was significantly higher than that of the control group. This suggests a role for the innate immunity in the pathology of venous leg ulcers, and indicates different roles for mannan-binding lectin in the development of ulcers with different aetiologies...

  8. Isolation of Cyclospora oocysts from fruits and vegetables using lectin-coated paramagnetic beads.

    Science.gov (United States)

    Robertson, L J; Gjerde, B; Campbell, A T

    2000-10-01

    Published techniques for recovering parasites from fruit and vegetables are generally inadequate, with low and variable recovery efficiencies. Herein, we describe an improved method for analyzing fruit and vegetables for Cyclospora oocysts. The technique includes washing procedures, sonication, and separation using lectin-coated paramagnetic beads. Identification is by microscopy (differential interference contrast and fluorescence). Oocyst recovery efficiencies from mushrooms, lettuce, and raspberries were approximately 12%. Recovery efficiencies from bean sprouts were approximately 4%. Although no significant difference in recovery efficiency could be detected between samples processed using the lectin-coated beads and samples processed without this procedure, distinct advantages were apparent when the lectin-coated beads were used. A considerably smaller, cleaner final volume remained for microscopy, which increases the sensitivity of the technique and reduces operator time.

  9. Cross-linked leucaena seed gum matrix: an affinity chromatography tool for galactose-specific lectins.

    Science.gov (United States)

    Seshagirirao, Kottapalli; Leelavathi, Chaganti; Sasidhar, Vemula

    2005-05-31

    A cross-linked leucaena (Leucaena leucocephala) seed gum (CLLSG) matrix was prepared for the isolation of galactose-specific lectins by affinity chromatography. The matrix was evaluated for affinity with a known galactose-specific lectin from the seeds of snake gourd (Trichosanthes anguina). The matrix preparation was simple and inexpensive when compared to commercial galactose-specific matrices (i.e. about 1.5 US dollars/100 ml of matrix). The current method is also useful for the demonstration of the affinity chromatography technique in laboratories. Since leucaena seeds are abundant and inexpensive, and the matrix preparation is easy, CLLSG appears to be a promising tool for the separation of galactose-specific lectins.

  10. Modulation of ovomucoid-specific oral tolerance in mice fed plant extracts containing lectins

    DEFF Research Database (Denmark)

    Kjær, Tanja; Frøkiær, Hanne

    2002-01-01

    We investigated the effect of feeding extracts of four different legumes (red kidney bean (Phaseolus vulgaris), peanut (Arachis hypogaea), soyabean (Glycine max) and pea (Pisum sativum) on the specific immune response against a food protein. Mice were fed ovomucoid and the specific immune response...... was evaluated. Ovomucoid fed alone resulted in oral tolerance induction measured as both a reduced ovomucoid-pecific spleen cell proliferation and antibody response. Feeding kidney-bean extract prevented induction of oral tolerance to ovomucoid measured as spleen cell proliferation in vitro. Pure kidney......-bean lectin also prevented oral tolerance induction, suggesting that lectin in the kidney-bean extract caused inhibition of oral tolerance. Parenteral administration (intravenous and intraperitoneal) of pure kidney-bean lectin had no significant influence on oral tolerance induction. Soyabean extract also...

  11. Evidence of gene conversion in genes encoding the Gal/GalNac lectin complex of Entamoeba.

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    Gareth D Weedall

    2011-06-01

    Full Text Available The human gut parasite Entamoeba histolytica, uses a lectin complex on its cell surface to bind to mucin and to ligands on the intestinal epithelia. Binding to mucin is necessary for colonisation and binding to intestinal epithelia for invasion, therefore blocking this binding may protect against amoebiasis. Acquired protective immunity raised against the lectin complex should create a selection pressure to change the amino acid sequence of lectin genes in order to avoid future detection. We present evidence that gene conversion has occurred in lineages leading to E. histolytica strain HM1:IMSS and E. dispar strain SAW760. This evolutionary mechanism generates diversity and could contribute to immune evasion by the parasites.

  12. [Effect of lectins from Azospirillum brasilense to peroxidase and oxalate oxidase activity regulation in wheat roots].

    Science.gov (United States)

    Alen'kina, S A; Nikitina, V E

    2010-01-01

    Lectins were extracted from the surface of nitrogen-fixing soil bacteria Azospirillum brasilense Sp7 and from its mutant A. brasilense Sp7.2.3 defective in lectin activity. The ability oflectins to stimulate the rapid formation of hydrogen peroxide related to increase of oxalate oxidase and peroxidase activity in the roots of wheat seedlings has been demonstrated. The most rapid induced pathway of hydrogen peroxide formation in the roots of wheat seedlings was the oxalic acid oxidation by oxalate oxidase which is the effect oflectin in under 10 min in a concentration of 10 microg/ml. The obtained results show that lectins from Azospirillum are capable of inducing the adaptation processes in the roots of wheat seedlings.

  13. Soybean Lectin Enhances Biofilm Formation by Bradyrhizobium japonicum in the Absence of Plants

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    Julieta Pérez-Giménez

    2009-01-01

    Full Text Available Soybean lectin (SBL purified from soybean seeds by affinity chromatography strongly bound to Bradyrhizobium japonicum USDA 110 cell surface. This lectin enhanced biofilm formation by B. japonicum in a concentration-dependent manner. Presence of galactose during biofilm formation had different effects in the presence or absence of SBL. Biofilms were completely inhibited in the presence of both SBL and galactose, while in the absence of SBL, galactose was less inhibitory. SBL was very stable, since its agglutinating activity of B. japonicum cells as well as of human group A+ erythrocytes was resistant to preincubation for one week at 60°C. Hence, we propose that plant remnants might constitute a source of this lectin, which might remain active in soil and thus favor B. japonicum biofilm formation in the interval between soybean crop seasons.

  14. Intracerebroventricular Administration of C-Type Natriuretic Peptide Suppresses Food Intake via Activation of the Melanocortin System in Mice

    OpenAIRE

    Yamada-Goto, Nobuko; Katsuura, Goro; Ebihara, Ken; Inuzuka, Megumi; Ochi, Yukari; Yamashita, Yui; Kusakabe, Toru; Yasoda, Akihiro; Satoh-Asahara, Noriko; Ariyasu, Hiroyuki; Hosoda, Kiminori; Nakao, Kazuwa

    2013-01-01

    C-type natriuretic peptide (CNP) and its receptor are abundantly distributed in the brain, especially in the arcuate nucleus (ARC) of the hypothalamus associated with regulating energy homeostasis. To elucidate the possible involvement of CNP in energy regulation, we examined the effects of intracerebroventricular administration of CNP on food intake in mice. The intracerebroventricular administration of CNP-22 and CNP-53 significantly suppressed food intake on 4-h refeeding after 48-h fastin...

  15. Flow cytometric analysis of lectin binding to in vitro-cultured Perkinsus marinus surface carbohydrates

    Science.gov (United States)

    Gauthier, J.D.; Jenkins, J.A.; La Peyre, Jerome F.

    2004-01-01

    Parasite surface glycoconjugates are frequently involved in cellular recognition and colonization of the host. This study reports on the identification of Perkinsus marinus surface carbohydrates by flow cytometric analyses of fluorescein isothiocyanate-conjugated lectin binding. Lectin-binding specificity was confirmed by sugar inhibition and Kolmogorov-Smirnov statistics. Clear, measurable fluorescence peaks were discriminated, and no parasite autofluorescence was observed. Parasites (GTLA-5 and Perkinsus-1 strains) harvested during log and stationary phases of growth in a protein-free medium reacted strongly with concanavalin A and wheat germ agglutinin, which bind to glucose-mannose and N-acetyl-D-glucosamine (GlcNAc) moieties, respectively. Both P. marinus strains bound with lower intensity to Maclura pomifera agglutinin, Bauhinia purpurea agglutinin, soybean agglutinin (N-acetyl-D-galactosamine-specific lectins), peanut agglutinin (PNA) (terminal galactose specific), and Griffonia simplicifolia II (GlcNAc specific). Only background fluorescence levels were detected with Ulex europaeus agglutinin I (L-fucose specific) and Limulus polyphemus agglutinin (sialic acid specific). The lectin-binding profiles were similar for the 2 strains except for a greater relative binding intensity of PNA for Perkinsus-1 and an overall greater lectin-binding capacity of Perkinsus-1 compared with GTLA-5. Growth stage comparisons revealed increased lectin-binding intensities during stationary phase compared with log phase of growth. This is the first report of the identification of surface glycoconjugates on a Perkinsus spp. by flow cytometry and the first to demonstrate that differential surface sugar expression is growth phase and strain dependent. ?? American Society of Parasitologists 2004.

  16. A novel core fucose-specific lectin from the mushroom Pholiota squarrosa.

    Science.gov (United States)

    Kobayashi, Yuka; Tateno, Hiroaki; Dohra, Hideo; Moriwaki, Kenta; Miyoshi, Eiji; Hirabayashi, Jun; Kawagishi, Hirokazu

    2012-10-05

    Fucα1-6 oligosaccharide has a variety of biological functions and serves as a biomarker for hepatocellular carcinoma because of the elevated presence of fucosylated α-fetoprotein (AFP) in this type of cancer. In this study we purified a novel Fucα1-6-specific lectin from the mushroom Pholiota squarrosa by ion-exchange chromatography and affinity chromatography on thyroglobulin-agarose. The purified lectin was designated as PhoSL (P. squarrosa lectin). SDS-PAGE, MALDI-TOF mass spectrometry, and N-terminal amino acid sequencing indicate that PhoSL has a molecular mass of 4.5 kDa and consists of 40 amino acids (NH(2)-APVPVTKLVCDGDTYKCTAYLDFGDGRWVAQWDTNVFHTG-OH). Isoelectric focusing of the lectin showed bands near pI 4.0. The lectin activity was stable between pH 2.0 and 11.0 and at temperatures ranging from 0 to 100 °C for incubation times of 30 min. When PhoSL was investigated with frontal affinity chromatography using 132 pyridylaminated oligosaccharides, it was found that the lectin binds only to core α1-6-fucosylated N-glycans and not to other types of fucosylated oligosaccharides, such as α1-2-, α1-3-, and α1-4-fucosylated glycans. Furthermore, PhoSL bound to α1-6-fucosylated AFP but not to non-fucosylated AFP. In addition, PhoSL was able to demonstrate the differential expression of α1-6 fucosylation between primary and metastatic colon cancer tissues. Thus, PhoSL will be a promising tool for analyzing the biological functions of α1-6 fucosylation and evaluating Fucα1-6 oligosaccharides as cancer biomarkers.

  17. 植物凝集素的功能%Plant lectins: multifunctions and applications

    Institute of Scientific and Technical Information of China (English)

    鲍锦库

    2011-01-01

    Plant lectins are carbohydrate-binding proteins with nonimmune origin, and they could bind carbohydrates reversibly, agglutinate cells or precipitate polysaccharides and glycoconjugates. Due to the specific binding activities towards polysaccharides and glycoconjugates of plant lectins, they play important roles in signaling pathways, immunoregulation and plant defence. In addition, plant lectins also possess hemagglutinating and carbohydrate-binding activities as well as the anti-viral and apoptosis-inducing properties. Therefore, plant lectins have been drawn a rising attention for researchers in bioscience, medicine and agriculture. In this review, we summarize the history and multifunctions of plant lectins, and also present the applications of plant lectins.%植物凝集素是来源于植物的一类能凝集细胞和沉淀单糖或多糖复合物的非免疫来源的非酶蛋白质.由于其对于单糖或糖复合物特异性结合的能力,使得其在如信号转导、免疫反应、植物防御等诸多信号过程中均具有重要作用.同时植物凝集素具有细胞凝集、抗病毒、抗真菌及诱导细胞凋亡或自噬等多种能力,因此在生命科学、医学及农业方面均有较好的研究价值和应用前景.综述了植物凝集素的研究历史和凝集素的主要功能,并对现阶段凝集素的重点应用做简要介绍.

  18. Lectin histochemistry of intestinal carbohydrate determinants in representatives of different classes of vertebrates

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    Antonyuk R.V.

    2015-12-01

    Full Text Available Background. Glycoproteins (including mucin of vertebrate’s intestine play an important role in its protection against chemical and mechanical damage and bacterial attacks. Their diversity was described by many authors, but understanding of their chemical structure remains far from complete. These data can be extended by methods of lectin histochemistry. Objective. To investigate the rearrangement of intestinal carbohydrate determinants in the context of vertebrate evolution. Methods. Distal and proximal segments of small and large intestines of humans (Homo sapiens, laboratory (Wistar rat (Rattus norvegicus f. Domesticus, rock pigeon (Columba livia, smooth snake (Coronella austriaca, common frog (Rana temporaria, common carp (Cyprinus carpio that belong to different classes of vertebrates were taken for the experiment. Nine lectins with different carbohydrate specificities: wheat germ (WGA, potato (STA, elderberry bark (SNA, golden rain bark (LABA, locust bark (RPBA, roe carp (CCRA, Phaseolus vulgaris erytroagglutinin (PHA-E, peanut (PNA and jack fruit (AIA – were included into the panel. Results. Differences in lectin staining between small and large intestine were more pronounced in higher (human, rat than in lower (frog, carp vertebrates. Lectin receptors were more diverse in frog intestine in comparison with carp. Lectin interaction with mucin secretory granules of smooth snake revealed lack of N-acetyl-D-glucosamine residues and abundance of N-acetyl-D-galactosamine determinants. Conclusion. Intestines of all studied vertebrate species demonstrate high content of secretory mucins that exposed terminal acidic carbohydrates including sialic acid. The diversity and differences in the structure of glycans of the digestive tract of vertebrates is apparently determined by several factors – diet, environmental and living conditions, intestinal microbiota interactions etc. Citation: Antonyuk RV, Lutsyk AD. [Lectin histochemistry of intestinal

  19. .Gov Domains API

    Data.gov (United States)

    General Services Administration — This dataset offers the list of all .gov domains, including state, local, and tribal .gov domains. It does not include .mil domains, or other federal domains outside...

  20. Crystallization and initial X-ray diffraction analysis of a mannose-binding lectin from champedak.

    Science.gov (United States)

    Gabrielsen, Mads; Abdul-Rahman, Puteri Shafinaz; Isaacs, Neil W; Hashim, Onn Haji; Cogdell, Richard J

    2010-05-01

    Mannose-binding lectin from champedak (Artocarpus integer) is a homotetramer with a single-monomer molecular weight of 16 800 Da. Previous work has shown it to bind IgE and IgM, as well as being a mitogen of T cells in humans. Champedak mannose-binding lectin has successfully been used to detect altered glycosylation states of serum proteins. The protein was crystallized at 293 K in space group P2(1)2(1)2(1) (unit-cell parameters a = 76.89, b = 86.22, c = 95.37 A) and the crystals diffracted to 2.0 A resolution.

  1. Assessment of lectin and HILIC based enrichment protocols for characterization of serum glycoproteins by mass spectrometry

    DEFF Research Database (Denmark)

    Calvano, Cosima D; Zambonin, Carlo G; Jensen, Ole Nørregaard

    2008-01-01

    glycosylation profiles are associated with certain human ailments. Glycoprotein analysis by mass spectrometry of biological samples, such as blood serum, is hampered by sample complexity and the low concentration of the potentially informative glycopeptides and -proteins. We assessed the utility of lectin...... of 63 glycosylation sites in 38 proteins were identified by both methods, demonstrating distinct differences and complementarity. Serial application of custom-made microcolumns of mixed, immobilized lectins proved efficient for recovery and analysis of glycopeptides from serum samples of breast cancer...

  2. Evolutionary conservation of mannan-binding lectin (MBL) in bony fish

    DEFF Research Database (Denmark)

    Kania, Per Walter; Sørensen, Rasmus Reng; Koch, Claus

    2010-01-01

    The complement system of fish is generally as complex as in mammals, and in addition Teleost fish often possess several genes encoding different subtypes of a given complement component, such as C3-1, C3-3 and C3-4. Initiators of both the classical (C1) and alternative pathway (factor B) have been...... characterized in the rainbow trout but so far no molecules of the lectin pathway have been identified. Based on the generally accepted idea of complement evolution, which predicts that the alternative pathway predates the two other pathways, and that the lectin pathway developed before the classical, we set out...

  3. Odorranalectin is a small peptide lectin with potential for drug delivery and targeting.

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    Jianxu Li

    Full Text Available BACKGROUND: Lectins are sugar-binding proteins that specifically recognize sugar complexes. Based on the specificity of protein-sugar interactions, different lectins could be used as carrier molecules to target drugs specifically to different cells which express different glycan arrays. In spite of lectin's interesting biological potential for drug targeting and delivery, a potential disadvantage of natural lectins may be large size molecules that results in immunogenicity and toxicity. Smaller peptides which can mimic the function of lectins are promising candidates for drug targeting. PRINCIPAL FINDINGS: Small peptide with lectin-like behavior was screened from amphibian skin secretions and its structure and function were studied by NMR, NMR-titration, SPR and mutant analysis. A lectin-like peptide named odorranalectin was identified from skin secretions of Odorrana grahami. It was composed of 17 aa with a sequence of YASPKCFRYPNGVLACT. L-fucose could specifically inhibit the haemagglutination induced by odorranalectin. (125I-odorranalectin was stable in mice plasma. In experimental mouse models, odorranalectin was proved to mainly conjugate to liver, spleen and lung after i.v. administration. Odorranalectin showed extremely low toxicity and immunogenicity in mice. The small size and single disulfide bridge of odorranalectin make it easy to manipulate for developing as a drug targeting system. The cyclic peptide of odorranalectin disclosed by solution NMR study adopts a beta-turn conformation stabilized by one intramolecular disulfide bond between Cys6-Cys16 and three hydrogen bonds between Phe7-Ala15, Tyr9-Val13, Tyr9-Gly12. Residues K5, C6, F7, C16 and T17 consist of the binding site of L-fucose on odorranalectin determined by NMR titration and mutant analysis. The structure of odorranalectin in bound form is more stable than in free form. CONCLUSION: These findings identify the smallest lectin so far, and show the application potential of

  4. Inhibition of human immunodeficiency virus 1 (HIV-1) and herpes simplex virus 1 (HSV-1) infectivity with a broad range of lectins

    DEFF Research Database (Denmark)

    Hansen, J E; Nielsen, C; Vestergaard, B F

    1991-01-01

    Five lectins with specificity for N- and O-linked oligosaccharides were examined for inhibition of HIV-1 and HSV-1 infectivity in vitro. HIV-1 isolate HTLVIIIB was preincubated with lectin and subsequently inoculated onto MT-4 cells. Lectins specific for N-linked oligosaccharides blocked HIV infe......-1 infection, the most potent inhibition was found with the lectin HPA. These results indicate that lectins may have a broad antiviral effect on enveloped viruses only limited by types of oligosaccharides present on individual viruses....

  5. Mouse Ficolin B Has an Ability to Form Complexes with Mannose-Binding Lectin-Associated Serine Proteases and Activate Complement through the Lectin Pathway

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    Yuichi Endo

    2012-01-01

    Full Text Available Ficolins are thought to be pathogen-associated-molecular-pattern-(PAMP- recognition molecules that function to support innate immunity. Like mannose-binding lectins (MBLs, most mammalian ficolins form complexes with MBL-associated serine proteases (MASPs, leading to complement activation via the lectin pathway. However, the ability of murine ficolin B, a homologue of human M-ficolin, to perform this function is still controversial. The results of the present study show that ficolin B in mouse bone marrow is an oligomeric protein. Ficolin B, pulled down using GlcNAc-agarose, contained very low, but detectable, amounts of MASP-2 and small MBL-associated protein (sMAP and showed detectable C4-deposition activity on immobilized N-acetylglucosamine. These biochemical features of ficolin B were confirmed using recombinant mouse ficolin B produced in CHO cells. Taken together, these results suggest that like other mammalian homologues, murine ficolin B has an ability to exert its function via the lectin pathway.

  6. Use of Aleuria alantia Lectin Affinity Chromatography to Enrich Candidate Biomarkers from the Urine of Patients with Bladder Cancer

    Directory of Open Access Journals (Sweden)

    Sarah R. Ambrose

    2015-09-01

    Full Text Available Developing a urine test to detect bladder tumours with high sensitivity and specificity is a key goal in bladder cancer research. We hypothesised that bladder cancer-specific glycoproteins might fulfill this role. Lectin-ELISAs were used to study the binding of 25 lectins to 10 bladder cell lines and serum and urine from bladder cancer patients and non-cancer controls. Selected lectins were then used to enrich glycoproteins from the urine of bladder cancer patients and control subjects for analysis by shotgun proteomics. None of the lectins showed a strong preference for bladder cancer cell lines over normal urothlelial cell lines or for urinary glycans from bladder cancer patients over those from non-cancer controls. However, several lectins showed a strong preference for bladder cell line glycans over serum glycans and are potentially useful for enriching glycoproteins originating from the urothelium in urine. Aleuria alantia lectin affinity chromatography and shotgun proteomics identified mucin-1 and golgi apparatus protein 1 as proteins warranting further investigation as urinary biomarkers for low-grade bladder cancer. Glycosylation changes in bladder cancer are not reliably detected by measuring lectin binding to unfractionated proteomes, but it is possible that more specific reagents and/or a focus on individual proteins may produce clinically useful biomarkers.

  7. Red kidney bean (Phaseolus vulgaris lectin stimulation increases the number of enterochromaffin cells in the small intestine of suckling piglets

    Directory of Open Access Journals (Sweden)

    Zacharko-Siembida Anna

    2014-06-01

    Full Text Available The quantities and distribution patterns of serotonin-immunoreactive (serotonin-IR enterochromaffin cells (EC were studied immunohistochemically in the small intestine of suckling piglets stimulated with red kidney bean lectin, and in nonstimulated, control animals. The co-expression patterns of serotonin with somatostatin (SOM or corticotropin releasing-factor (CRF were also studied. After the lectin treatment, the increased numbers of EC were noted in the duodenum of experimental animals. Lectin stimulation did not change the proportions of EC in the jejunum and ileum. In the duodenal epithelium of the lectin-stimulated piglets, the vast majority of serotonin-IR EC were distributed at the basis of crypts. After the lectin administration, the proportions of serotonin-IR/SOM-IR EC were statistically similar in all sections of the small intestine. No upregulation of CRF was found in duodenal, jejunal, and ileal EC of lectin-treated animals. The findings demonstrated that red kidney bean lectin increased the serotonin reservoir in the duodenum, and thus may be an effective stimulant of the gut maturation in suckling mammals.

  8. A Galactose-Binding Lectin Isolated from Aplysia kurodai (Sea Hare Eggs Inhibits Streptolysin-Induced Hemolysis

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    Imtiaj Hasan

    2014-09-01

    Full Text Available A specific galactose-binding lectin was shown to inhibit the hemolytic effect of streptolysin O (SLO, an exotoxin produced by Streptococcus pyogenes. Commercially available lectins that recognize N-acetyllactosamine (ECA, T-antigen (PNA, and Tn-antigen (ABA agglutinated rabbit erythrocytes, but had no effect on SLO-induced hemolysis. In contrast, SLO-induced hemolysis was inhibited by AKL, a lectin purified from sea hare (Aplysia kurodai eggs that recognizes α-galactoside oligosaccharides. This inhibitory effect was blocked by the co-presence of d-galactose, which binds to AKL. A possible explanation for these findings is that cholesterol-enriched microdomains containing glycosphingolipids in the erythrocyte membrane become occupied by tightly stacked lectin molecules, blocking the interaction between cholesterol and SLO that would otherwise result in penetration of the membrane. Growth of S. pyogenes was inhibited by lectins from a marine invertebrate (AKL and a mushroom (ABA, but was promoted by a plant lectin (ECA. Both these inhibitory and promoting effects were blocked by co-presence of galactose in the culture medium. Our findings demonstrate the importance of glycans and lectins in regulating mechanisms of toxicity, creation of pores in the target cell membrane, and bacterial growth.

  9. Cytotoxic and Antiproliferative Effect of Tepary Bean Lectins on C33-A, MCF-7, SKNSH, and SW480 Cell Lines

    Directory of Open Access Journals (Sweden)

    Carmen Valadez-Vega

    2014-07-01

    Full Text Available For many years, several studies have been employing lectin from vegetables in order to prove its toxic effect on various cell lines. In this work, we analyzed the cytotoxic, antiproliferative, and post-incubatory effect of pure tepary bean lectins on four lines of malignant cells: C33-A; MCF-7; SKNSH, and SW480. The tests were carried out employing MTT and 3[H]-thymidine assays. The results showed that after 24 h of lectin exposure, the cells lines showed a dose-dependent cytotoxic effect, the effect being higher on MCF-7, while C33-A showed the highest resistance. Cell proliferation studies showed that the toxic effect induced by lectins is higher even when lectins are removed, and in fact, the inhibition of proliferation continues after 48 h. Due to the use of two techniques to analyze the cytotoxic and antiproliferative effect, differences were observed in the results, which can be explained by the fact that one technique is based on metabolic reactions, while the other is based on the 3[H]-thymidine incorporated in DNA by cells under division. These results allow concluding that lectins exert a cytotoxic effect after 24 h of exposure, exhibiting a dose-dependent effect. In some cases, the cytotoxic effect is higher even when the lectins are eliminated, however, in other cases, the cells showed a proliferative effect.

  10. Isolation of a galactose-binding lectin from the venom of the snake Bothrops godmani (Godmann's pit viper).

    Science.gov (United States)

    Lomonte, B; Rojas, G; Gutiérrez, J M; Ramírez, G

    1990-01-01

    A galactose-binding lectin, isolated from the venom of B. godmani by affinity chromatography, is an acidic protein (pI 4.9) with a subunit mol. wt of about 14,000, occurring mostly as a disulfide-linked dimer of 28,000. A small proportion of lectin appears as a monomer and as a tetramer. The lectin agglutinates erythrocytes from mice, rabbit, cow and human (all ABO types, either Rh positive or negative), but does not agglutinate horse, sheep, goat and snake (Oxybelis aeneus, Colubridae) erythrocytes. The agglutinating activity is inhibited by 1 mM EDTA. The lectin is devoid of lethal, hemorrhagic, myotoxic, proteolytic and phospholipase A2 activities. It is not mitogenic for human peripheral blood mononuclear cells. The only effect observed was a moderate induction of edema in the footpad of mice, with a minimal edema-forming dose of 22 micrograms. This effect developed rapidly, and was significantly inhibited by i.p. administration of cyproheptadine, a histamine and serotonin antagonist, before injection of the lectin. Despite the edema-forming activity observed, the low concentration of lectin in crude venom, together with its relatively low potency, suggest that this lectin is not a key component in the development of edema following envenomations by B. godmani.

  11. In vitro and in vivo interaction of Entamoeba histolytica Gal/GalNAc lectin with various target cells: an immunocytochemical analysis.

    Science.gov (United States)

    Pacheco, Judith; Shibayama, Mineko; Campos, Rafael; Beck, David L; Houpt, Erick; Petri, William A; Tsutsumi, Víctor

    2004-03-01

    The Gal/GalNAc lectin of Entamoeba histolytica trophozoites plays an important role in adhesion. The distribution and final destiny of the lectin during the interaction with host cells are poorly understood. Using monoclonal and polyclonal antibodies against the lectin we studied by immunocytochemistry the in vitro and in vivo interaction of E. histolytica trophozoites with human and hamster hepatocytes. We also analyzed the presence and distribution of the lectin in a mouse model of intestinal amoebiasis. In all cases, trophozoites were highly labeled by anti-lectin antibodies. Cultured human and hamster hepatocytes in contact with, or localized at the vicinity of parasites were also labeled by anti-lectin antibodies. Most of the labeled hepatocytes showed variable degrees of cell damage. Hepatocytes distantly localized from the parasites were also stained with the anti-lectin antibodies. Immunolabeling of tissue sections from different stages of the development of experimental amoebic liver abscess in hamsters showed inflammatory foci containing lectin-labeled trophozoites, hepatocytes, and sinusoidal and inflammatory cells. Lectin-containing hepatocytes had vacuolated cytoplasm with some nuclei with a condensed appearance. Damaged intestinal epithelium also was labeled with anti-lectin antibodies in a mouse model of intestinal amoebiasis. Electron microscopy of axenically cultured trophozoites using gold-labeled monoclonal and polyclonal anti-lectin antibody showed that plasma membrane, vacuole membranes and areas of cell cytosol were labeled. Higher deposits of gold particles in plasma membrane suggestive of cell secretion were observed. Our results demonstrated that Gal/GalNAc lectin was bound and captured by different target cells, and that host cells containing the lectin showed signs of cell damage. The contribution of lectin transfer to host cells in adherence and cell injury remains to be determined.

  12. Mannan-binding lectin in cerebrospinal fluid: a leptomeningeal protein

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    Reiber Hansotto

    2012-08-01

    Full Text Available Abstract Background Mannan-binding lectin (MBL, a protein of the innate immune response is attracting increasing clinical interest, in particularly in relation to its deficiency. Due to its involvement in brain diseases, identifying the source of MBL in CSF is important. Analysis of cerebrospinal fluid (CSF can provide data that discriminates between blood-, brain-, and leptomeninges-derived proteins. To detect the source of MBL in CSF we need to consider three variables: the molecular size-dependent concentration gradient between CSF and blood, the variation in transfer between blood and CSF, and the CSF MBL concentration correlation with the albumin CSF/serum quotient (QAlb, i.e., with CSF flow rate. Methods MBL was assayed in samples of CSF and serum with an ELISA, coated with anti MBL antibodies. Routine parameters such as albumin-, immunoglobulin- CSF/serum quotients, oligoclonal IgG and cell count were used to characterize the patient groups. Groups comprised firstly, control patients without organic brain disease with normal CSF and normal barrier function and secondly, patients without inflammatory diseases but with increased QAlb, i.e. with a blood CSF barrier dysfunction. Results MBL concentration in CSF was at least five-fold higher than expected for a molecular-size-dependent passage from blood. Secondly, in a QIgM/QAlb quotient diagram (Reibergram 9/13 cases showed an intrathecal fraction in some cases over 80% of total CSF MBL concentration 3 The smaller inter-individual variation of MBL concentrations in CSF of the control group (CV = 66% compared to the MBL concentrations in serum (CV = 146% indicate an independent source of MBL in CSF. 4 The absolute MBL concentration in CSF increases with increasing QAlb. Among brain-derived proteins in CSF only the leptomeningeal proteins showed a (linear increase with decreasing CSF flow rate, neuronal and glial proteins are invariant to changes of QAlb. Conclusions MBL in CSF is

  13. Lectin-carbohydrate interactions on nanoporous gold monoliths.

    Science.gov (United States)

    Tan, Yih Horng; Fujikawa, Kohki; Pornsuriyasak, Papapida; Alla, Allan J; Ganesh, N Vijaya; Demchenko, Alexei V; Stine, Keith J

    2013-07-01

    Monoliths of nanoporous gold (np-Au) were modified with self-assembled monolayers of octadecanethiol (C18-SH), 8-mercaptooctyl α-D-mannopyranoside (αMan-C8-SH), and 8-mercapto-3,6-dioxaoctanol (HO-PEG2-SH), and the loading was assessed using thermogravimetric analysis (TGA). Modification with mixed SAMs containing αMan-C8-SH (at a 0.20 mole fraction in the SAM forming solution) with either octanethiol or HO-PEG2-SH was also investigated. The np-Au monoliths modified with αMan-C8-SH bind the lectin Concanavalin A (Con A), and the additional mass due to bound protein was assessed using TGA analysis. A comparison of TGA traces measured before and after exposure of HO-PEG2-SH modified np-Au to Con A showed that the non-specific binding of Con A was minimal. In contrast, np-Au modified with octanethiol showed a significant mass loss due to non-specifically adsorbed Con A. A significant mass loss was also attributed to binding of Con A to bare np-Au monoliths. TGA revealed a mass loss due to the binding of Con A to np-Au monoliths modified with pure αMan-C8-SH. The use of mass losses determined by TGA to compare the binding of Con A to np-Au monoliths modified by mixed SAMs of αMan-C8-SH and either octanethiol or HO-PEG2-SH revealed that binding to mixed SAM modified surfaces is specific for the mixed SAMs with HO-PEG2-SH but shows a significant contribution from non-specific adsorption for the mixed SAMs with octanethiol. Minimal adsorption of immunoglobulin G (IgG) and peanut agglutinin (PNA) towards the mannoside modified np-Au monoliths was demonstrated. A greater mass loss was found for Con A bound onto the monolith than for either IgG or PNA, signifying that the mannose presenting SAMs in np-Au retain selectivity for Con A. TGA data also provide evidence that Con A bound to the αMan-C8-SH modified np-Au can be eluted by flowing a solution of methyl α-D-mannopyranoside through the structure. The presence of Con A proteins on the modified np-Au surface was

  14. Lectin-based glycoproteomics to explore and analyze hepatocellular carcinoma-related glycoprotein markers.

    Science.gov (United States)

    Dai, Zhi; Zhou, Jian; Qiu, Shuang-Jian; Liu, Yin-Kun; Fan, Jia

    2009-09-01

    More and more new diagnostic biomarkers of hepatocellular carcinoma (HCC) have been found in association with advances in the standardization of 2-DE coupled with MS analysis. However, the diagnosis of HCC is still detected in the late stages of the disease, when treatment options are limited and prognosis is poor. The glycosylation of proteins is known to change in tumor cells during the development of HCC as the result of alterations in the levels of glycosyltransferases, such as increased fucosylation of Golgi Protein 73 and alpha-fetoprotein. These structural changes can influence the function or physiochemical properties of a protein, resulting in abnormal cancer cell behavior. Therefore, identification of HCC-related glycoprotein markers and analysis of glycan structural alterations might assist in the early detection of HCC. Here, we summarize lectin-based glycoproteomic strategies for the discovery of relevant biomarkers of HCC. The carbohydrate-binding specificities of different lectins offer a biological affinity approach that complements existing MS capabilities. These strategies involve the enrichment of glycoproteins or glycopeptides by lectins, followed by releasing carbohydrates with peptide-N-glycosidase F or reductive beta-elimination. The obtained glycopeptides are then identified by automated MS/MS and structural analysis of glycans is performed through modern methods such as quadrupole IT-TOF, MALDI-TOF/TOF and lectin microarray. These strategies will lead to faster and more clinically adaptable tests with greater sensitivity and specificity.

  15. Purification of Colocasia esculenta lectin and determination of its anti-insect potential towards Bactrocera cucurbitae.

    Science.gov (United States)

    Thakur, Kshema; Kaur, Manpreet; Kaur, Satwinder; Kaur, Amritpal; Kamboj, Sukhdev Singh; Singh, Jatinder

    2013-01-01

    The present study reports the purification of a lectin from Colocasia esculenta (L.) Schott corms and evaluation of its anti-insect potential towards Bactrocera cucurbitae (Coquilett). The lectin was found to be specific towards N-acetyl-D-lactosamine (LacNac), a disaccharide and asialofetuin, a desialylated serum glycoprotein in hemagglutination inhibition assay. Asialofetuin was used as a ligand to purify Colocasia esculenta agglutinin (CEA) by affinity chromatography. The purity of CEA was ascertained by the presence of a single band in reducing SDS-PAGE at pH 8.3. The affinity purified CEA was employed in artificial diet bioassay of second instar larvae (64-72 hr old) of the B. cucurbitae at concentrations ranging between 10-160 microg ml(-1). The lectin significantly (p < 0.01) decreased the percent pupation and emergence with respect to control. Effect on various enzymes was studied by employing LC50 (51.6 microg ml(-1)) CEA in the artificial diet bioassay of second instar larvae. All the enzymes tested namely esterases, phosphatases (acid and alkaline), superoxide dismutases, catalase and glutathione-S-transferase showed a significant (p < 0.01, p < 0.05) increase in their enzyme and specific activities. These results showed that CEA affected normal growth and development and presented stress to the larvae, activating their detoxification and anti-oxidant systems. Thus, the lectin seems to be a useful candidate for the control measures of B. cucurbitae under the integrated pest management (IPM) system.

  16. Using crystallographic water properties for the analysis and prediction of lectin-carbohydrate complex structures.

    Science.gov (United States)

    Modenutti, C; Gauto, D; Radusky, L; Blanco, J; Turjanski, A; Hajos, S; Marti, Ma

    2015-02-01

    Understanding protein-ligand interactions is a fundamental question in basic biochemistry, and the role played by the solvent along this process is not yet fully understood. This fact is particularly relevant in lectins, proteins that mediate a large variety of biological processes through the recognition of specific carbohydrates. In the present work, we have thoroughly analyzed a nonredundant and well-curated set of lectin structures looking for a potential relationship between the structural water properties in the apo-structures and the corresponding protein-ligand complex structures. Our results show that solvent structure adjacent to the binding sites mimics the ligand oxygen structural framework in the resulting protein-ligand complex, allowing us to develop a predictive method using a Naive Bayes classifier. We also show how these properties can be used to improve docking predictions of lectin-carbohydrate complex structures in terms of both accuracy and precision, thus developing a solid strategy for the rational design of glycomimetic drugs. Overall our results not only contribute to the understanding of protein-ligand complexes, but also underscore the role of the water solvent in the ligand recognition process. Finally, we discuss our findings in the context of lectin specificity and ligand recognition properties.

  17. Toward a structure-based comprehension of the lectin pathway of complement

    DEFF Research Database (Denmark)

    Kjaer, Troels R; Thiel, Steffen; Andersen, Gregers R

    2013-01-01

    To initiate the lectin pathway of complement pattern recognition molecules bind to surface-linked carbohydrates or acetyl groups on pathogens or damaged self-tissue. This leads to activation of the serine proteases MASP-1 and MASP-2 resulting in deposition of C4 on the activator and assembly...

  18. Toward a structure-based comprehension of the lectin pathway of complement.

    Science.gov (United States)

    Kjaer, Troels R; Thiel, Steffen; Andersen, Gregers R

    2013-12-15

    To initiate the lectin pathway of complement pattern recognition molecules bind to surface-linked carbohydrates or acetyl groups on pathogens or damaged self-tissue. This leads to activation of the serine proteases MASP-1 and MASP-2 resulting in deposition of C4 on the activator and assembly of the C3 convertase. In addition MASP-3 and the non-catalytic MAp19 and MAp44 presumably play regulatory functions, but the exact function of the MASP-3 protease remains to be established. Recent functional studies have significantly advanced our understanding of the molecular events occurring as activation progresses from pattern recognition to convertase assembly. Furthermore, atomic structures derived by crystallography or solution scattering of most proteins acting in the lectin pathway and two key complexes have become available. Here we integrate the current functional and structural knowledge concerning the lectin pathway proteins and derive overall models for their glycan bound complexes. These models are used to discuss cis- versus trans-activation of MASP proteases and the geometry of C4 deposition occurring on glycans in the lectin pathway.

  19. Lectin binding patterns in hyperplastic and metaplastic bullock prostate tissues after diethylstilbestrol administration.

    Science.gov (United States)

    Fernández, P E; Barbeito, C G; Portiansky, E L; Gimeno, E J

    2004-03-06

    Hyperplasia and squamous metaplasia of the prostatic epithelium are conditions induced by oestrogens. Diethylstilbestrol (DES) has been banned from cattle used for beef production because of the health risks. The potential use of molecular markers for the detection of illegal oestrogen administration was evaluated by taking samples of prostatic tissue from control bullocks, bullocks which had been treated with oestrogens, and bullocks sacrificed 21 and 90 days after a single dose of DES. The expression of the glycoconjugates was examined by lectinhistochemistry and the lectin binding pattern was characterised in epithelium and connective tissue. In the animals sacrificed after 21 days there was an increase in the binding of one lectin (JAC) and there was an increase in the binding of one of the other lectins (DBA) in the animals sacrificed after 90 days. An increase in SWGA lectin staining was observed in the bullocks that had probably been treated with oestrogen and in the animals sacrificed 90 days after the inoculation with DES. There were also differences between the binding of SWGA in the control bullocks and the other groups.

  20. Mannose-binding lectin genotypes and susceptibility to epstein-barr virus infection in infancy

    DEFF Research Database (Denmark)

    Friborg, Jeppe T; Jarrett, Ruth F; Koch, Anders

    2010-01-01

    In a cohort study of children <4 years of age in Greenland, mannose-binding lectin (MBL2) genotypes and Epstein-Barr virus (EBV) antibody levels were determined. EBV seropositivity was significantly lower and time to seroconversion increased in MBL-insufficient compared with MBL-sufficient childr...

  1. Enrichment and identification of glycoproteins in human saliva using lectin magnetic bead arrays.

    Science.gov (United States)

    Caragata, Michael; Shah, Alok K; Schulz, Benjamin L; Hill, Michelle M; Punyadeera, Chamindie

    2016-03-15

    Aberrant glycosylation of proteins is a hallmark of tumorigenesis and could provide diagnostic value in cancer detection. Human saliva is an ideal source of glycoproteins due to the relatively high proportion of glycosylated proteins in the salivary proteome. Moreover, saliva collection is noninvasive and technically straightforward, and the sample collection and storage is relatively easy. Although differential glycosylation of proteins can be indicative of disease states, identification of differential glycosylation from clinical samples is not trivial. To facilitate salivary glycoprotein biomarker discovery, we optimized a method for differential glycoprotein enrichment from human saliva based on lectin magnetic bead arrays (saLeMBA). Selected lectins from distinct reactivity groups were used in the saLeMBA platform to enrich salivary glycoproteins from healthy volunteer saliva. The technical reproducibility of saLeMBA was analyzed with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify the glycosylated proteins enriched by each lectin. Our saLeMBA platform enabled robust glycoprotein enrichment in a glycoprotein- and lectin-specific manner consistent with known protein-specific glycan profiles. We demonstrated that saLeMBA is a reliable method to enrich and detect glycoproteins present in human saliva.

  2. Effect of Moringa oleifera lectin on development and mortality of Aedes aegypti larvae.

    Science.gov (United States)

    Coelho, Juliene S; Santos, Nataly D L; Napoleão, Thiago H; Gomes, Francis S; Ferreira, Rodrigo S; Zingali, Russolina B; Coelho, Luana C B B; Leite, Sônia P; Navarro, Daniela M A F; Paiva, Patrícia M G

    2009-11-01

    Aedes aegypti larvae have developed tolerance to many insecticides used for mosquito control. Moringa oleifera seeds contain a water-soluble lectin (WSMoL) and this paper reports the effect of M. oleifera seed extracts (MoE(1-15)) and WSMoL on development and survival of A. aegypti larvae. WSMoL peptide from in-gel trypsin digestion is also described. MoE(1-15) showed hemagglutinating activity and WSMoL had similarity with flocculating proteins from M. oleifera seeds. MoE(1) and MoE(3) delayed larval development which stopped in the third instar (L3) in MoE(6) and MoE(15). Significant (p<0.0001) larval mortality was only detected in MoE(15). Native WSMoL showed larvicidal activity (LC(50) 0.197 mg mL(-1)) and heated lectin, without hemagglutinating activity, did not kill fourth instar (L4) larvae. Optical microscopy showed that live L4 from MoE(1) presented underlying epithelium, increased gut lumen and hypertrophic segments; dead L4 from WSMoL were absent of underlying epithelium, had increased gut lumen and hypertrophic segments. The presence of hemagglutinating activity in the extracts suggests that soluble lectin promotes the delay of larval development and mortality; furthermore, the absence of larvicidal activity in heat-denatured WSMoL strengthens the involvement of lectin in this activity mechanism.

  3. Developmental changes affecting lectin binding in the vomeronasal organ of domestic pigs, Sus scrofa.

    Science.gov (United States)

    Park, Junwoo; Lee, Wonho; Jeong, Chanwoo; Kim, Hwangryong; Taniguchi, Kazumi; Shin, Taekyun

    2012-01-01

    This study investigated the developmental changes of glycoconjugate patterns in the porcine vomeronasal organs (VNOs) and associated glands (Jacobson's glands) from prenatal (9 weeks of gestation) and postnatal (2 days after birth) to the sexually mature stage (6 months old). The VNO of pigs (Sus scrofa) was examined using the following: Dolichos biflorus agglutinin (DBA), Bandeiraea simplicifolia agglutinin isolectin B4 (BSI-B4), Triticum vulgaris agglutinin (WGA), Ulex europaeus agglutinin I (UEA-I), and soybean agglutinin (SBA). At the fetal stage, all lectins examined were detected mainly in the free border of the vomeronasal epithelium, but few (WGA and UEA-I) and or absent in the VNO cell bodies. At the postnatal and sexually mature stages, the reactivity of some lectins, including WGA, UEA-I, DBA and SBA, were shown to increase in the VNO sensory epithelium as well as the free border. The increased reactivity of lectins as development progressed was also observed in Jacobson's gland acini. These findings suggest that binding sites of lectins, including those of WGA, UEA-I, DBA, and SBA, increase during development from fetal to postnatal growth, possibly contributing to the increased ability of chemoreception in the pig.

  4. The typing of Staphylococcus epidermidis by a lectin-binding assay

    DEFF Research Database (Denmark)

    Jarløv, J O; Hansen, J E; Rosdahl, V T

    1992-01-01

    plates. The amount of bound lectin was measured by peroxidase-conjugated avidin followed by a peroxidase reaction. The method was compared to antibiotic-resistance analysis, phage typing, plasmid DNA profiles and slime production. A total of 113 isolates of CNS from 21 patients was investigated and 71...

  5. Expression of lectin-like transcript 1, the ligand for CD161, in rheumatoid arthritis

    NARCIS (Netherlands)

    Chalan, P.; Bijzet, J.; Kroesen, B.-J.; Brouwer, Liesbeth; Boots, M.

    2015-01-01

    Background: Precursor Th17 lineage cells expressing CD161 are implicated in rheumatoid arthritis pathogenesis. CD4+CD161+ T cells were found to accumulate in RA synovial fluid and tissue where they may acquire a non-classical T-helper 1 phenotype. The sole endogenous ligand for CD161 is lectin-like

  6. Isolation and characterization of a novel lectin with antifungal and antiproliferative activities from Sophora alopecuroides seeds

    Institute of Scientific and Technical Information of China (English)

    Tinging Li; Xiaoli Yin; Dongliang Liu; Xiaojin Ma; Hui Lv; Surong Sun

    2012-01-01

    Sophora alopecuroides lectin (SAL),a novel lectin from the seeds of Sophora alopecuroides,was purified by ionexchange chromatography on diethylaminoethyl (DEAE)-and carboxymethyl (CM)-Sepharose columns,followed by gel filtration on a Sephadex 75 10/300 GL column.SAL was found to be a monomer of 39916.3 Da,as determined by tricine-sodium dodecyl sulphate-polyacrylamide gel electrophoresis and high-performance liquid chromato-graphy (HPLC).The N-terminal 10-amino acid sequence of SAL,KPWALSFSFG,resembles those of other legume lectins.SAL exhibits hemagglutinating activity against rabbit erythrocytes at 11.9 μg/ml.Its hemagglutinating activity is stable in the pH range 7-11 and in the temperature range 30-90℃,and is stimulated by Mn2+.The hemagglutinating activity of SAL is most potently inhibited by 50-mM D-galactose.SAL suppresses mycelial growth in Penicillium digitatum and Alternaria alternata;the IC50 of the antifungal activity toward P.digitatum and A.alternata were found to be 3.125 and 3.338 μM,respectively.SAL suppresses the proliferation of human cervical cancer cells (HeLa) at an ICso of 6.25 μM (P< 0.05).But it has no inhibiting effect on bacteria.This is the first report of a lectin from seeds of S.alopecuroides.

  7. Preoperative mannan-binding lectin pathway and prognosis in colorectal cancer

    DEFF Research Database (Denmark)

    Ytting, Henriette; Christensen, Ib Jarle; Jensenius, Jens Christian

    2005-01-01

    PURPOSE: Deficiency of the mannan-binding lectin (MBL) pathway of innate immunity is associated with increased susceptibility to infections. In patients with colorectal cancer (CRC), postoperative infection is associated with poor prognosis. The aim of the present study was to evaluate (1...

  8. Lectin histochemistry of Kudoa septempunctata genotype ST3-infected muscle of olive flounder (Paralichthys olivaceus

    Directory of Open Access Journals (Sweden)

    Kang Jaeyoun

    2016-01-01

    Full Text Available The localization of carbohydrate terminals in Kudoa septempunctata ST3-infected muscle of olive flounder (Paralichthys olivaceus was investigated using lectin histochemistry to determine the types of carbohydrate sugar residues expressed in Kudoa spores. Twenty-one lectins were examined, i.e., N-acetylglucosamine (s-WGA, WGA, DSL-II, DSL, LEL, STL, mannose (Con A, LCA, PSA, galactose/N-acetylgalactosamine (RCA12, BSL-I, VVA, DBA, SBA, SJA, Jacalin, PNA, ECL, complex type N-glycans (PHA-E and PHA-L, and fucose (UEA-I. Spores encased by a plasmodial membrane were labeled for the majority of these lectins, with the exception of LCA, PSA, PNA, and PHA-L. Four lectins (RCA 120, BSL-I, DBA, and SJA belonging to the galactose/N-acetylgalactosamine group, only labeled spores, but not the plasmodial membrane. This is the first confirmation that various sugar residues are present in spores and plasmodial membranes of K. septempunctata ST3.

  9. Evaluation of glycophenotype in breast cancer by quantum dot-lectin histochemistry.

    Science.gov (United States)

    Andrade, Camila G; Cabral Filho, Paulo E; Tenório, Denise P L; Santos, Beate S; Beltrão, Eduardo I C; Fontes, Adriana; Carvalho, Luiz B

    2013-01-01

    Cell surface glycoconjugates play an important role in differentiation/dedifferentiation processes and lectins are employed to evaluate them by several methodologies. Fluorescent probes are considered a valuable tool because of their ability to provide a particular view, and are more detailed and sensitive in terms of cell structure and molecular content. The aim of this study was to evaluate and compare the expression and distribution of glycoconjugates in normal human breast tissue, and benign (fibroadenoma), and malignantly transformed (invasive ductal carcinoma) breast tissues. For this, we used mercaptosuccinic acid-coated Cadmium Telluride (CdTe) quantum dots (QDs) conjugated with concanavalin A (Con A) or Ulex europaeus agglutinin I (UEA I) lectins to detect α-D-glucose/mannose and L-fucose residues, respectively. The QD-lectin conjugates were evaluated by hemagglutination activity tests and carbohydrate inhibition assays, and were found to remain functional, keeping their fluorescent properties and carbohydrate recognition ability. Fluorescence images showed that different regions of breast tissue expressed particular types of carbohydrates. While the stroma was preferentially and intensely stained by QD-Con A, ductal cells were preferentially labeled by QD-UEA I. These results indicate that QD-lectin conjugates can be used as molecular probes and can help to elucidate the glycoconjugate profile in biological processes.

  10. Purification of a secreted lectin from Andrias davidianus skin and its antibacterial activity.

    Science.gov (United States)

    Qu, Min; Tong, Changqing; Kong, Liang; Yan, Xin; Chernikov, Oleg V; Lukyanov, Pavel A; Jin, Qiao; Li, Wei

    2015-01-01

    A lectin secreted from Andrias davidianus skin (ADL) was purified by affinity chromatography on porcine stomach mucin (type III) (PSM)-crosslinked albumin, followed by gel filtration on Sephadex G-100 and HPLC on TSK gel G3000PWXL. The purified lectin was found to be a dimeric protein, as revealed by SDS-PAGE and MALDI-TOF analysis. SDS-PAGE showed that the ADL protein had a molecular mass of 17 kDa. ADL produced an 8.5 kDa band when examined using SDS-PAGE under reducing conditions. ADL agglutinated native and trypsinized human B erythrocytes. The hemagglutination activity was inhibited by glycoproteins, such as PSM and asialo-PSM, but not by any of the monosaccharides tested. The activity was stable between 4 °C and 50 °C. Significant ADL activity was observed between pH 4–5. The lectin reaction did not depend on the presence of the divalent cation Ca2+ or Mg2+. The N-terminal ADL sequence was determined to be VGYTVGATPM. The lectin exhibited antibacterial activity, involving growth and respiration inhibition in Escherichia coli, Enterobacter aerogenes, Staphylococcus aureus, Bacillus subtilis and Shewanella sp. Furthermore, ADL showed inhibition activity against the yeast Saccharomyces cerevisiae. These findings suggest that ADL plays an important role in the innate immunity of A. davidianus on the body surface.

  11. Second-generation nanofiltered plasma-derived mannan-binding lectin product

    DEFF Research Database (Denmark)

    Laursen, I.; Houen, G.; Højrup, P.

    2007-01-01

    BACKGROUND AND OBJECTIVES: Mannan-binding lectin (MBL) is an important component of the innate immune defence; it binds to carbohydrate structures on pathogenic micro-organisms resulting in complement activation and opsonization. Individuals with low MBL levels are at risk of recurrent and severe...

  12. Mannan-binding lectin polymorphisms and serum levels in patients with endometriosis

    DEFF Research Database (Denmark)

    Kruse, Christina; Steffensen, Rudi; Nielsen, Hans J;

    2014-01-01

    OBJECTIVE: To investigate a possible association between endometriosis and low levels of mannan-binding lectin (MBL). STUDY DESIGN: Case-control study of blood samples from 100 patients with endometriosis compared with results from a group of 350 blood donors. RESULT: The frequency of MBL levels...... endometriosis and low levels of MBL....

  13. Structural Insight into Multivalent Galactoside Binding to Pseudomonas aeruginosa Lectin LecA

    NARCIS (Netherlands)

    Visini, Ricardo; Jin, Xian; Bergmann, Myriam; Michaud, Gaelle; Pertici, Francesca; Fu, Ou; Pukin, Aliaksei; Branson, Thomas R.; Thies-Weesie, Dominique M E; Kemmink, Johan; Gillon, Emilie; Imberty, Anne; Stocker, Achim; Darbre, Tamis; Pieters, Roland J.; Reymond, Jean Louis

    2015-01-01

    Multivalent galactosides inhibiting Pseudomonas aeruginosa biofilms may help control this problematic pathogen. To understand the binding mode of tetravalent glycopeptide dendrimer GalAG2 [(Gal-β-OC6H4CO-Lys-Pro-Leu)4(Lys-Phe-Lys-Ile)2Lys-His-Ile-NH2] to its target lectin LecA, crystal structures of

  14. Lotus corniculatus nodulation specificity is changed by the presence of a soybean lectin gene

    Science.gov (United States)

    van Rhijn P; Goldberg; Hirsch

    1998-08-01

    Plant lectins have been implicated as playing an important role in mediating recognition and specificity in the Rhizobium-legume nitrogen-fixing symbiosis. To test this hypothesis, we introduced the soybean lectin gene Le1 either behind its own promoter or behind the cauliflower mosaic virus 35S promoter into Lotus corniculatus, which is nodulated by R. loti. We found that nodulelike outgrowths developed on transgenic L. corniculatus plant roots in response to Bradyrhizobium japonicum, which nodulates soybean and not Lotus spp. Soybean lectin was properly targeted to L. corniculatus root hairs, and although infection threads formed, they aborted in epidermal or hypodermal cells. Mutation of the lectin sugar binding site abolished infection thread formation and nodulation. Incubation of bradyrhizobia in the nodulation (nod) gene-inducing flavonoid genistein increased the number of nodulelike outgrowths on transgenic L. corniculatus roots. Studies of bacterial mutants, however, suggest that a component of the exopolysaccharide surface of B. japonicum, rather than Nod factor, is required for extension of host range to the transgenic L. corniculatus plants.

  15. A `Clicked' Tetrameric Hydroxamic Acid Glycopeptidomimetic Antagonizes Sugar-Lectin Interactions On The Cellular Level

    Science.gov (United States)

    Zhang, Hai-Lin; Zang, Yi; Xie, Juan; Li, Jia; Chen, Guo-Rong; He, Xiao-Peng; Tian, He

    2014-07-01

    A tetrameric N-acetyl galactosaminyl (GalNAc) peptidomimetic was constructed by N-acetylation of repeating proline-based hydroxamic acid units, followed by a convergent `click chemistry' coupling. This novel glycopeptidomimetic was determined to effectively antagonize the interaction between a transmembrane hepatic lectin and GalNAc on the cellular level.

  16. Immunogold study on lectin binding in the porcine zona pellucida and granulosa cells

    Directory of Open Access Journals (Sweden)

    F Parillo

    2009-06-01

    Full Text Available An ultrastructural localization of lectin receptors on the zona pellucida (ZP of porcine antral oocytes and on the granulosa cells was performed using a panel of horseradish peroxidase- labelled lectins in conjunction with antiperoxidase antibody and protein A-gold. In some cases, lectin incubation was preceded by sialidase digestion. WGA-, Con-A-, UEA-I-, RCA-I-, PNA- and SBA-reactive sites were distributed differently in the porcine ZP. Sialidase digestion increased the positivity obtained with RCA-I and it was necessary to promote PNA and SBA reactivity. These results indicated that the ZP contained N-acetylglucosamine, a-mannose, a- fucose, b-Gal-(1-4GlcNAc, b-Gal- (1-3GalNAc, b-GalNAc and sialic acid residues. We also observed the presence of vesicles in both the ooplasm and granulosa cells, showing a similar lectin binding pattern to that of the ZP, thus suggesting that the oocyte and granulosa cells are the site of synthesis of ZP glucidic determinants.

  17. Glycophenotype Evaluation in Cutaneous Tumors Using Lectins Labeled with Acridinium Ester

    Directory of Open Access Journals (Sweden)

    Luiza Rayanna Amorim Lima

    2013-01-01

    Full Text Available Background. Tumor cells show alterations in their glycosylation patterns when compared to normal cells. Lectins can be used to evaluate these glycocode changes. Chemiluminescence assay is an effective technique for quantitative analysis of proteins, nucleic acids, and carbohydrates due to its high sensitivity, specificity, and rapid testing. Objective. To use histochemiluminescence based on lectin conjugated to acridinium ester (AE for the investigation of glycophenotype changes in cutaneous tumors. Methods. Concanavalin A (Con A, Peanut agglutinin (PNA, Ulex europaeus agglutinin-I (UEA-I, and Maackia amurensis agglutinin (MAA were conjugated to acridinium ester. Biopsies of cutaneous tumors and normal skin were incubated with the lectins-AE, and chemiluminescence was quantified and expressed as Relative Light Units (RLU. Results. Actinic keratosis (AK, keratoacanthoma (KA, squamous cell carcinoma (SCC, and basal cell carcinoma (BCC showed lower expression of α-D-glucose/mannose and α-L-fucose residues compared to normal tissue. Cutaneous tumors displayed higher expression of Gal-β(1-3-GalNAc residues than normal tissue. AK and SCC exhibited higher expression of Neu5Ac-α(2,3Gal residues than normal epidermis. KA and BCC showed equivalent RLU values compared to normal tissue. Conclusions. Lectin histochemiluminescence allowed quantitative assessment of the carbohydrate expression in cutaneous tissues, contributing to eliminate the subjectivity of conventional techniques used in the histopathological diagnosis.

  18. Influence of major surgery on the mannan-binding lectin pathway of innate immunity

    DEFF Research Database (Denmark)

    Ytting, H; Christensen, I J; Basse, L;

    2006-01-01

    The mannan-binding lectin (MBL) pathway of complement activation is important in host defence against pathogens and possibly against cancer. We investigated the effect of major surgery on two central components of the MBL pathway; MBL and the MBL-associated serine protease MASP-2, and for compari...

  19. Lectin Digestibility and Stability of Elderberry Antioxidants to Heat Treatment In Vitro

    Directory of Open Access Journals (Sweden)

    Pilar Jiménez

    2017-01-01

    Full Text Available Elderberry contains healthy low molecular weight nutraceuticals and lectins which are sequence-related to the elderberry allergen Sam n1. Some of these lectins are type II ribosome-inactivating proteins. The sensitivity of native lectins present in elderberry fruits and bark to the proteolysis triggered by in vitro simulated gastric and duodenal fluids has been investigated. It was found that these lectins are refractory to proteolysis. Nonetheless, incubation for 5–10 min in a boiling water bath completely sensitized them to the hydrolytic enzymes in vitro. Under these conditions neither total Folin-Ciocalteau’s reagent reactive compounds, total anthocyanins and the mixture of cyanidin-3-glucoside plus cyanidin-3-sambubioside, nor antioxidant and free-radical scavenging activities were affected by more than 10% for incubations of up to 20 min. Therefore, short-time heat treatment reduces potential allergy-related risks deriving from elderberry consumption without seriously affecting its properties as an antioxidant and free-radical scavenging food.

  20. The use of lectins as markers for differentiated secretory cells in planarians.

    Science.gov (United States)

    Zayas, Ricardo M; Cebrià, Francesc; Guo, Tingxia; Feng, Junjie; Newmark, Phillip A

    2010-11-01

    Freshwater planarians have reemerged as excellent models to investigate mechanisms underlying regeneration. The introduction of molecular tools has facilitated the study of planarians, but cell- and tissue-specific markers are still needed to examine differentiation of most cell types. Here we report the utility of fluorescent lectin-conjugates to label tissues in the planarian Schmidtea mediterranea. We show that 16 lectin-conjugates stain planarian cells or tissues; 13 primarily label the secretory cells, their cytoplasmic projections, and terminal pores. Thus, we examined regeneration of the secretory system using lectin markers and functionally characterized two genes expressed in the secretory cells: marginal adhesive gland-1 (mag-1) and Smed-reticulocalbin1 (Smed-rcn1). RNAi knockdown of these genes caused a dramatic reduction of secretory cell lectin staining, suggesting a role for mag-1 and Smed-rcn1 in secretory cell differentiation. Our results provide new insights into planarian secretory system regeneration and add new markers for labeling several planarian tissues.

  1. Snowdrop lectin (Galanthus nivalis agglutinin) in aphid honeydew negatively affects survival of a honeydew- consuming parasitoid

    NARCIS (Netherlands)

    Hogervorst, P.A.M.; Wäckers, F.L.; Woodring, J.; Romeis, J.

    2009-01-01

    1 Insecticidal proteins can be excreted in the honeydew when sap-sucking insects feed on insect-resistant transgenic plants. Honeydew can be an important source of carbohydrates, thus potentially exposing a broad range of honeydew-feeding insects to transgene products. 2 Snowdrop lectin (Galanthus n

  2. Ficolin-3-mediated lectin complement pathway activation in patients with subarachnoid hemorrhage

    DEFF Research Database (Denmark)

    Zanier, Elisa R; Zangari, Rosalia; Munthe-Fog, Lea

    2014-01-01

    OBJECTIVES: To assess the involvement of ficolin-3, the main initiator of the lectin complement pathway (LCP), in subarachnoid hemorrhage (SAH) pathology and outcome. METHODS: In this preliminary exploratory study, plasma concentration of ficolin-3 and of ficolin-3-mediated functional LCP activit...

  3. Effects of mannose-binding lectin polymorphisms on irinotecan-induced febrile neutropenia

    NARCIS (Netherlands)

    J.M. van der Bol (Jessica); M.J.A. de Jonge (Maja); R.H.N. van Schaik (Ron); A. Sparreboom (Alex); M.A. van Fessem (Marianne); F.E. Geijn (Fleur); P.L.A. van Daele (Paul); J. Verweij (Jaap); S. Sleijfer (Stefan); A.H.J. Mathijssen (Ron)

    2010-01-01

    textabstractObjective. Mannose-binding lectin (MBL) is important in the innate immune response. MBL2 gene polymorphisms affect MBL expression, and genotypes yielding low MBL levels have been associated with an elevated risk for infections in hematological cancer patients undergoing chemotherapy. How

  4. The role of mannose-binding lectin (MBL) in paediatric oncology patients with febrile neutropenia

    NARCIS (Netherlands)

    F.N.J. Frakking; M.D. van de Wetering; N. Brouwer; K.M. Dolman; J. Geissler; B. Lemkes; H.N. Caron; T.W. Kuijpers

    2006-01-01

    Children with cancer often have fever during chemotherapy-induced neutropenia, but only some develop serious infectious complications. Mannose-binding lectin (MBL) deficiency might increase infection susceptibility in these children. MBL genotype and phenotype were prospectively determined in 110 pa

  5. Carbohydrate Detection and Lectin Isolation from Tegumental Tissue of Fasciola hepatica

    Directory of Open Access Journals (Sweden)

    MB Molaei Rad

    2010-02-01

    Full Text Available "nBackground: Fascioliasis is a chronic hepatic disease and may be resulted from mechani­cal/molecular parasite adhesion to host liver tissue. The aim of this study was to detect surface car­bohydrate and lectin, carbohydrate-binding protein isolation that might be responsible of this molecular binding."nMethods: The present experimental work was conducted in the Department of Medical Parasitol­ogy and Mycology, School of Public Health, Tehran University of Medical Sciences, Te­hran, Iran.  Fasciola hepatica parasites were collected from abattoir (Saman, Tehran, Iran and surface mannose-carbohydrate was detected by fluorescein isothiocyanate (FITC conju­gated lectin (Lentil. Lectin of tegumental tissue from F. hepatica was isolated by affinity chroma­tography and detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE."nResults: Mannose carbohydrate was observed on the surface of tegumental tissue from para­site under fluorescence microscope. Carbohydrate-binding protein or lectin with MW of 50 kDa also was isolated from homogenized tegument of helminth."nConclusion: These results are important for understanding of molecular pathogenesis of F. hepat­ica at the chronic phase of fascioliasis

  6. Feline Lectin Activity Is Critical for the Cellular Entry of Feline Infectious Peritonitis Virus▿

    OpenAIRE

    Regan, Andrew D.; Ousterout, David G.; Whittaker, Gary R.

    2010-01-01

    Feline infectious peritonitis is a lethal disease of felids caused by systemic infection with a feline coronavirus. Here, we report identification and analysis of the feline homologue to the human lectin DC-SIGN and show that it is a coreceptor for virulent strains of serotype 1 and serotype 2 feline coronaviruses.

  7. Feline lectin activity is critical for the cellular entry of feline infectious peritonitis virus.

    Science.gov (United States)

    Regan, Andrew D; Ousterout, David G; Whittaker, Gary R

    2010-08-01

    Feline infectious peritonitis is a lethal disease of felids caused by systemic infection with a feline coronavirus. Here, we report identification and analysis of the feline homologue to the human lectin DC-SIGN and show that it is a coreceptor for virulent strains of serotype 1 and serotype 2 feline coronaviruses.

  8. Molecular cloning, genomic organization, and expression of a C-type (Manduca sexta-type) allatostatin preprohormone from Drosophila melanogaster

    DEFF Research Database (Denmark)

    Williamson, M; Lenz, C; Winther, A M

    2001-01-01

    The insect allatostatins are a diverse group of neuropeptides that obtained their names by their inhibitory actions on the corpora allata (two endocrine glands near the insect brain), where they block the biosynthesis of juvenile hormone (a terpenoid important for development and reproduction...... neurons of the brain and abdominal ganglia and in endocrine cells of the midgut. This is the first publication on the structure of a C-type allatostatin from insects other than moths and the first report on the presence of all three types of allatostatins in a representative of the insect order Diptera...

  9. Respiration of metal (hydr)oxides by Shewanella and Geobacter: a key role for multihaem c-type cytochromes

    OpenAIRE

    Shi, Liang; Squier, Thomas C.; Zachara, John M.; Fredrickson, James K.

    2007-01-01

    Dissimilatory reduction of metal (e.g. Fe, Mn) (hydr)oxides represents a challenge for microorganisms, as their cell envelopes are impermeable to metal (hydr)oxides that are poorly soluble in water. To overcome this physical barrier, the Gram-negative bacteria Shewanella oneidensis MR-1 and Geobacter sulfurreducens have developed electron transfer (ET) strategies that require multihaem c-type cytochromes (c-Cyts). In S. oneidensis MR-1, multihaem c-Cyts CymA and MtrA are believed to transfer ...

  10. Mannose-binding lectin deficiency and acute exacerbations of chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Woodruff PG

    2012-11-01

    Full Text Available Richard K Albert,1 John Connett,2 Jeffrey L Curtis,3,4 Fernando J Martinez,3 MeiLan K Han,3 Stephen C Lazarus,5 Prescott G Woodruff51Medicine Service, Denver Health and Department of Medicine, University of Colorado Denver, Denver, CO, 2Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, 3Pulmonary and Critical Care Medicine, Department of Medicine, University of Michigan, Ann Arbor, MI, 4Pulmonary and Critical Care Medicine, VA Medical Center, Ann Arbor, MI, 5Pulmonary and Critical Care Medicine, Department of Medicine, and Cardiovascular Research Institute, University of California, San Francisco, CA, USABackground: Mannose-binding lectin is a collectin involved in host defense against infection. Whether mannose-binding lectin deficiency is associated with acute exacerbations of chronic obstructive pulmonary disease is debated.Methods: Participants in a study designed to determine if azithromycin taken daily for one year decreased acute exacerbations had serum mannose-binding lectin concentrations measured at the time of enrollment.Results: Samples were obtained from 1037 subjects (91% in the trial. The prevalence of mannose-binding lectin deficiency ranged from 0.5% to 52.2%, depending on how deficiency was defined. No differences in the prevalence of deficiency were observed with respect to any demographic variable assessed, and no differences were observed in time to first exacerbation, rate of exacerbations, or percentage of subjects requiring hospitalization for exacerbations in those with deficiency versus those without, regardless of how deficiency was defined.Conclusion: In a large sample of subjects with chronic obstructive pulmonary disease selected for having an increased risk of experiencing an acute exacerbation of chronic obstructive pulmonary disease, only 1.9% had mannose-binding lectin concentrations below the normal range and we found no association between mannose-binding lectin

  11. Lectin-like receptor for alpha 1-acid glycoprotein in the epithelium of the rat prostate gland and seminal vesicles

    DEFF Research Database (Denmark)

    Andersen, U O; Bøg-Hansen, T C; Kirkeby, S

    1996-01-01

    BACKGROUND: A receptor for alpha 1-acid glycoprotein glycoforms AGP-B and AGP-C in the epithelium of the rat prostate gland and seminal vesicles is described. METHODS: The interaction between AGP-glycoforms and their receptor is a lectin-like interaction confirmed by inhibition of the binding...... in rat prostate and seminal vesicles. The localization of the AGP lectin receptor is compared to the localization of glycoprotein AGP, and small differences are found. CONCLUSIONS: It is proposed the AGP receptors in the prostate and seminal vesicles belong to a group of lectins in the control...

  12. Carbohydrate/glycan-binding specificity of legume lectins in respect to their proposed biological functions

    Directory of Open Access Journals (Sweden)

    Márcio Viana Ramos

    2000-01-01

    Full Text Available The lectins, proteins which specifically recognize carbohydrate moieties, have been extensively studied in many biochemical and structural aspects in order to establish the molecular basis of this non-catalytic event. On the other hand, their clinical and agricultural potentials have been growing fast. Although lectins, mainly those from legume plants, had been investigated for biological properties, studies about the physiological functions of lectins are scarce in literature. Therefore, despite the accumulated data on lectins (as proteins, the role played by these signalizing molecules is poorly discussed. In the light of our accumulated results on legume lectins, specially those obtained from plants belonging to the Diocleinae sub-tribe and available data in literature, we discuss here the main hypothesis of their functions according to their carbohydrate/glycan-binding specificity.As lectinas, proteinas que especificamente reconhecem estruturas que contém carboidratos, têm sido extensivamente estudadas em muitos aspectos bioquímicos e estruturais, objetivando estabelecer as bases moleculares deste evento não-catalítico. Por outro lado, os potenciais clínicos e agriculturais destas proteínas têm crescido rapidamente. Embora as lectinas, principalmente aquelas de legumes tenham sido bastante investigadas em suas propriedades biológicas, estudos sobre as funcões fisiológicas de lectinas são escassos na literatura. Além disto, a despeito da quantidade de dados acumulados sobre lectinas (como proteínas, o papel desempenhado por estas moléculas de sinalização é pobremente discutido. Valendo-se de nossos estudos sobre lectinas de leguminosas, principalmente da sub-tribo Diocleinae, e outros dados presentes na literatura, discutimos aqui, as principais hipóteses de suas funções com base na especificidade por carboidratos e glicanos complexos.

  13. The C-type natriuretic peptide induces thermal hyperalgesia through a noncanonical Gβγ-dependent modulation of TRPV1 channel.

    Science.gov (United States)

    Loo, Lipin; Shepherd, Andrew J; Mickle, Aaron D; Lorca, Ramón A; Shutov, Leonid P; Usachev, Yuriy M; Mohapatra, Durga P

    2012-08-29

    Natriuretic peptides (NPs) control natriuresis and normalize changes in blood pressure. Recent studies suggest that NPs are also involved in the regulation of pain sensitivity, although the underlying mechanisms remain essentially unknown. Many biological effects of NPs are mediated by guanylate cyclase (GC)-coupled NP receptors, NPR-A and NPR-B, whereas the third NP receptor, NPR-C, lacks the GC kinase domain and acts as the NP clearance receptor. In addition, NPR-C can couple to specific Gα(i)-Gβγ-mediated intracellular signaling cascades in numerous cell types. We found that NPR-C is coexpressed in transient receptor potential vanilloid-1 (TRPV1)-expressing mouse dorsal root ganglia (DRG) neurons. NPR-C can be coimmunoprecipitated with Gα(i), and C-type natriuretic peptide (CNP) treatment induced translocation of protein kinase Cε (PKCε) to the plasma membrane of these neurons, which was inhibited by pertussis toxin pretreatment. Application of CNP potentiated capsaicin- and proton-activated TRPV1 currents in cultured mouse DRG neurons and increased their firing frequency, an effect that was absent in DRG neurons from TRPV1(-/-) mice. CNP-induced sensitization of TRPV1 activity was attenuated by pretreatment of DRG neurons with the specific inhibitors of Gβγ, phospholipase C-β (PLCβ), or PKC, but not of protein kinase A, and was abolished by mutations at two PKC phosphorylation sites in TRPV1. Furthermore, CNP injection into mouse hindpaw led to the development of thermal hyperalgesia that was attenuated by administration of specific inhibitors of Gβγ or TRPV1 and was also absent in TRPV1(-/-) mice. Thus, our work identifies the Gβγ-PLCβ-PKC-dependent potentiation of TRPV1 as a novel signaling cascade recruited by CNP in mouse DRG neurons that can lead to enhanced nociceptor excitability and thermal hypersensitivity.

  14. Plant lectins, from ancient sugar-binding proteins to emerging anti-cancer drugs in apoptosis and autophagy.

    Science.gov (United States)

    Jiang, Q-L; Zhang, S; Tian, M; Zhang, S-Y; Xie, T; Chen, D-Y; Chen, Y-J; He, J; Liu, J; Ouyang, L; Jiang, X

    2015-02-01

    Ubiquitously distributed in different plant species, plant lectins are highly diverse carbohydrate-binding proteins of non-immune origin. They have interesting pharmacological activities and currently are of great interest to thousands of people working on biomedical research in cancer-related problems. It has been widely accepted that plant lectins affect both apoptosis and autophagy by modulating representative signalling pathways involved in Bcl-2 family, caspase family, p53, PI3K/Akt, ERK, BNIP3, Ras-Raf and ATG families, in cancer. Plant lectins may have a role as potential new anti-tumour agents in cancer drug discovery. Thus, here we summarize these findings on pathway- involved plant lectins, to provide a comprehensive perspective for further elucidating their potential role as novel anti-cancer drugs, with respect to both apoptosis and autophagy in cancer pathogenesis, and future therapy.

  15. [Comparative assessment of inductive effects of Azospirillum lectins with different antigenic properties on the signal systems of wheat seedling roots].

    Science.gov (United States)

    Alen'kina, S A; Petrova, L P; Sokolova, M K; Chernyshova, M P; Trutneva, K A; Bogatyrev, V A; Nikitina, V E

    2014-01-01

    The lectins of associative nitrogen-fixing bacteria Azospirillum brasilense Sp7 and its mutant A. brasilense Sp7.2.3 were shown to have different effects on the components of the wheat seedling root signal system, namely to regulate the levels of cAMP, nitric oxide, diacylglycerol, and salicylic acid, as well as to induce the activities of superoxide dismutase and lipoxygenase. Our results make it possible to consider azospirilla lectins as inducers of the signal systems in wheat seedling roots, since they cause development of several flows of primary signals. These data are of general biological importance, since lectins are present in all living organisms and most ot the functions of lectins remain insufficiently understood.

  16. Solanum tuberosum lectin inhibits Ehrlich ascites carcinoma cells growth by inducing apoptosis and G2/M cell cycle arrest.

    Science.gov (United States)

    Kabir, Syed Rashel; Rahman, Md Musfikur; Amin, Ruhul; Karim, Md Rezaul; Mahmud, Zahid Hayat; Hossain, M Tofazzal

    2016-06-01

    Recently, a lectin was purified from the potato cultivated in Bangladesh locally known as Sheel. In the pr