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James P Tam - One of the best experts on this subject based on the ideXlab platform.
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anti fungal Hevein like peptides biosynthesized from quinoa cleavable hololectins
Molecules, 2021Co-Authors: Shining Loo, Daiwen Yang, Stephanie Victoria Tay, Antony Kam, Fan Tang, Jingsong Fan, James P TamAbstract:Chitin-binding Hevein-like peptides (CB-HLPs) belong to a family of cysteine-rich peptides that play important roles in plant stress and defense mechanisms. CB-HLPs are ribosomally synthesized peptides that are known to be bioprocessed from the following two types of three-domain CB-HLP precursor architectures: cargo-carrying and non-cargo-carrying. Here, we report the identification and characterization of chenotides biosynthesized from the third type of precursors, which are cleavable hololectins of the quinoa (Chenopodium quinoa) family. Chenotides are 6-Cys-CB-HLPs of 29–31 amino acids, which have a third type of precursor architecture that encompasses a canonical chitin-binding domain that is involved in chitin binding and anti-fungal activities. Microbroth dilution assays and microscopic analyses showed that chenotides are effective against phyto-pathogenic fungi in the micromolar range. Structure determination revealed that chenotides are cystine knotted and highly compact, which could confer resistance against heat and proteolytic degradation. Importantly, chenotides are connected by a novel 18-residue Gly/Ala-rich linker that is a target for bioprocessing by cathepsin-like endopeptidases. Taken together, our findings reveal that chenotides are a new family of CB-HLPs from quinoa that are synthesized as a single multi-modular unit and bioprocessed to yield individual mature CB-HLPs. Importantly, such precursors constitute a new family of cleavable hololectins. This unusual feature could increase the biosynthetic efficiency of anti-fungal CB-HLPs, to provide an evolutionary advantage for plant survival and reproduction.
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vaccatides antifungal glutamine rich Hevein like peptides from vaccaria hispanica
Frontiers in Plant Science, 2017Co-Authors: Ka H Wong, Wei Liang Tan, Aida Serra, Tianshu Xiao, Siu Kwan Sze, Shruthi G Kini, James P TamAbstract:Hevein and Hevein-like peptides are disulfide-constrained chitin-binding cysteine-rich peptides. They are divided into three subfamilies, 6C-, 8C- and 10C-Hevein-like peptides, based on the number of cysteine residues. In addition, Hevein-like peptides can exist in two forms, short and long. The long C-terminal form found in Hevein and 10C-Hevein-like peptides contain a C-terminal protein cargo. In contrast, the short form without a protein cargo is found in all three subfamilies. Here, we report the discovery and characterization of two novel glutamine-rich and protein cargo-free 8C-Hevein-like peptides, vaccatides vH1 and vH2, from Vaccaria hispanica of the Caryophyllaceae family. Proteomic analyses showed that the vaccatides are 40‒41 amino acids in length and contain a chitin-binding domain. NMR determination revealed that vaccatide vH2 displays a highly compact structure with a cystine knot at the N-terminus and an additional disulfide bond at the C-terminus. Stability studies showed that this compact structure renders vaccatide vH2 resistant to thermal, chemical and proteolytic degradation. The chitin-binding vH2 was shown to inhibit the mycelium growth of four phyto-pathogenic fungal strains with IC50 values in the micromolar range. Our findings show that vaccatides represent a new family of 8C-Hevein-like peptides, which are protein cargo-free and glutamine-rich, characteristics that differentiate them from the prototypic Hevein and the 10C-Hevein-like peptides.Together, this study expands the existing library of Hevein-like peptides and provides insight into their molecular diversity in sequence, structure and biosynthesis. Additionally, their highly disulfide-constrained structure could be used as a scaffold for developing metabolically and orally active peptidyl therapeutics.
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Vaccatides: Antifungal Glutamine-Rich Hevein-Like Peptides from Vaccaria hispanica
Frontiers Media S.A., 2017Co-Authors: Ka H Wong, Wei Liang Tan, Aida Serra, Tianshu Xiao, Shruthi G Kini, Sui Kwan Sze, James P TamAbstract:Hevein and Hevein-like peptides are disulfide-constrained chitin-binding cysteine-rich peptides. They are divided into three subfamilies, 6C-, 8C-, and 10C-Hevein-like peptides, based on the number of cysteine residues. In addition, Hevein-like peptides can exist in two forms, short and long. The long C-terminal form found in Hevein and 10C-Hevein-like peptides contain a C-terminal protein cargo. In contrast, the short form without a protein cargo is found in all three subfamilies. Here, we report the discovery and characterization of two novel glutamine-rich and protein cargo-free 8C-Hevein-like peptides, vaccatides vH1 and vH2, from Vaccaria hispanica of the Caryophyllaceae family. Proteomic analyses showed that the vaccatides are 40–41 amino acids in length and contain a chitin-binding domain. NMR determination revealed that vaccatide vH2 displays a highly compact structure with a N-terminal cystine knot and an addition C-terminal disulfide bond. Stability studies showed that this compact structure renders vaccatide vH2 resistant to thermal, chemical and proteolytic degradation. The chitin-binding vH2 was shown to inhibit the mycelium growth of four phyto-pathogenic fungal strains with IC50 values in the micromolar range. Our findings show that vaccatides represent a new family of 8C-Hevein-like peptides, which are protein cargo-free and glutamine-rich, characteristics that differentiate them from the prototypic Hevein and the 10C-Hevein-like peptides. In summary, this study enriches the existing library of Hevein-like peptides and provides insight into their molecular diversity in sequence, structure and biosynthesis. Additionally, their highly disulfide-constrained structure could be used as a scaffold for developing metabolically and orally active peptidyl therapeutics
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Morintides: cargo-free chitin-binding peptides from Moringa oleifera
'Springer Science and Business Media LLC', 2017Co-Authors: Shruthi G Kini, Wei Liang Tan, Tianshu Xiao, Ka H. Wong, James P TamAbstract:Abstract Background Hevein-like peptides are a family of cysteine-rich and chitin-binding peptides consisting of 29–45 amino acids. Their chitin-binding property is essential for plant defense against fungi. Based on the number of cysteine residues in their sequences, they are divided into three sub-families: 6C-, 8C- and 10C-Hevein-like peptides. All three subfamilies contain a three-domain precursor comprising a signal peptide, a mature Hevein-like peptide and a C-terminal domain comprising a hinge region with protein cargo in 8C- and 10C-Hevein-like peptides. Results Here we report the isolation and characterization of two novel 8C-Hevein-like peptides, designated morintides (mO1 and mO2), from the drumstick tree Moringa oleifera, a drought-resistant tree belonging to the Moringaceae family. Proteomic analysis revealed that morintides comprise 44 amino acid residues and are rich in cysteine, glycine and hydrophilic amino acid residues such as asparagine and glutamine. Morintides are resistant to thermal and enzymatic degradation, able to bind to chitin and inhibit the growth of phyto-pathogenic fungi. Transcriptomic analysis showed that they contain a three-domain precursor comprising an endoplasmic reticulum (ER) signal sequence, a mature peptide domain and a C-terminal domain. A striking feature distinguishing morintides from other 8C-Hevein-like peptides is a short and protein-cargo-free C-terminal domain. Previously, a similar protein-cargo-free C-terminal domain has been observed only in ginkgotides, the 8C-Hevein-like peptides from a gymnosperm Ginkgo biloba. Thus, morintides, with a cargo-free C-terminal domain, are a stand-alone class of 8C-Hevein-like peptides from angiosperms. Conclusions Our results expand the existing library of Hevein-like peptides and shed light on molecular diversity within the Hevein-like peptide family. Our work also sheds light on the anti-fungal activity and stability of 8C-Hevein-like peptides
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ginkgotides proline rich Hevein like peptides from gymnosperm ginkgo biloba
Frontiers in Plant Science, 2016Co-Authors: Ka H Wong, Wei Liang Tan, Aida Serra, Tianshu Xiao, Siu Kwan Sze, Daiwen Yang, James P TamAbstract:Hevein and Hevein-like peptides belong to the family of chitin-binding cysteine-rich peptides. They are classified into three subfamilies, the prototypic 8C- and the 6C- and 10C-Hevein-like peptides. Thus far, only five 8C-Hevein-like peptides have been characterized from three angiosperms and none from gymnosperm. To determine their occurrence and distribution in the gymnosperm, Ginkgo biloba leaves were examined. Here, we report the discovery and characterization of eleven novel 8C-Hevein-like peptides, namely ginkgotides gB1–gB11. Proteomic analysis showed that the ginkgotides contain 41–44 amino acids (aa), a chitin-binding domain and are Pro-rich, a distinguishing feature that differs from other Hevein-like peptides. Solution 1H-NMR structure determination revealed that gB5 contains a three β-stranded structure shaped by a cystine knot with an additional disulfide bond at the C-terminus. Transcriptomic analysis showed that the ginkgotide precursors contain a three-domain architecture, comprised of a C-terminal tail (20 aa) that is significantly shorter than those of other 8C- and 10C-Hevein-like peptides, which generally contain a protein cargo such as a Barwin-like protein (126 aa) or class I chitinase (254 aa). Transcriptomic data mining found an additional 48 ginkgotide homologs in 39 different gymnosperms. Phylogenetic analysis revealed that ginkgotides and their homologs belong to a new class of 8C-Hevein-like peptides. Stability studies showed that ginkgotides are highly resistant to thermal, acidic and endopeptidase degradation. Ginkgotides flanked at both the N- and C-terminal ends by Pro were resistant to exopeptidase degradation by carboxypeptidase A and aminopeptidase. Antifungal assays showed that ginkgotides inhibit the hyphal growth of phyto-pathogenic fungi. Taken together, ginkgotides represent the first suite of Hevein-like peptides isolated and characterized from gymnosperms. As a group, they represent a novel class of 8C-Hevein-like peptides that are Pro-rich and protein-cargo free. Our findings also suggest that the ginkgotide scaffold could be useful for engineering metabolic-stable peptide therapeutics.
Jesus Jimenezbarbero - One of the best experts on this subject based on the ideXlab platform.
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insights into the dynamics and molecular recognition features of glycopeptides by protein receptors the 3d solution structure of Hevein bound to the trisaccharide core of n glycoproteins
Chemistry: A European Journal, 2010Co-Authors: Jose Juan Hernandezgay, Ana Arda, Steffen Eller, Stefano Mezzato, Bas R Leeflang, Carlo Unverzagt, Javier F Canada, Jesus JimenezbarberoAbstract:Protein-carbohydrate interactions are at the heart of a variety of essential molecular recognition events. Hevein, a model lectin related to the superantigen family, recognizes the trisaccharide core of N-glycoproteins (1). A combined approach of NMR spectroscopy and molecular modeling has permitted us to demonstrate that an Asn-linked Man(GlcNAc)2 (2) is bound with even higher affinity than (GlcNAc)3. The molecular recognition process entails conformational selection of only one of the possibilities existing for chitooligosaccharides. The deduced 3D structure of the Hevein/2 complex permits the extension of polypeptide chains from the Asn moiety of 2, as well as glycosylation at Man O-3 and Man O-6 of the terminal sugar. Given the ubiquity of the Man(GlcNAc)2 core in all mammalian N-glycoproteins, the basic recognition mode presented herein might be extended to a variety of systems with biomedical importance.
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effect of a serine to aspartate replacement on the recognition of chitin oligosaccharides by truncated Hevein a 3d view by using nmr
Carbohydrate Research, 2010Co-Authors: Maria Isabel Chavez, Francisco Javier Canada, Miquel Vilaperello, David Andreu, Jesus JimenezbarberoAbstract:Abstract The interaction of a synthetically prepared mutant peptide of Hevein (a well known chitin-binding lectin) Hev32S19D with chitin oligosaccharides (and chitosan analogues) has allowed us to estimate their affinity constants and associated thermodynamic data. The mutant peptide is able to bind chitin oligomers, but with significant decreases in the association constants with chito-oligosaccharides. The determination of the three-dimensional structure of the peptide mutant, by using NMR, has permitted us to deduce that the topology of the backbone is very similar to that of the parent Hev32 peptide. The same is true regarding the orientations of the key aromatic residues Trp21, Trp23, and Tyr30. The decrease in the association constants can be attributed to the different topological orientation of key side chains and to the importance of protein–sugar intermolecular essential hydrogen bonds and CH–π stacking interactions. The analysis has permitted us to infer the free energy of binding associated with these interactions as well as to estimate the corresponding binding enthalpy.
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Hevein domains an attractive model to study carbohydrate protein interactions at atomic resolution
Advances in Carbohydrate Chemistry and Biochemistry, 2006Co-Authors: Jesus Jimenezbarbero, Juan Luis Asensio, Francisco Javier Canada, Nuria Aboitiz, Paloma Vidal, Angeles Canales, Patrick Groves, Hansjoachim Gabius, Hanschristian SiebertAbstract:Publisher Summary This chapter focuses on Hevein domains and presents an attractive model to study carbohydrate–protein interactions at atomic resolution. Among the various biological processes in which carbohydrates are involved as biochemical signals, it is noteworthy that many plants harbor defense proteins (lectins) against pathogenic attack. These proteins are able to bind to chitin. This natural biopolymer is a key structural component of the cell wall of fungi and of the exoskeleton of invertebrates such as insects, nematodes, and arthropods. Direct binding to the saccharide can occur for the respective lectin, while a particular domain can also be instrumental for chitin-degrading enzymes. The antifungal activity of plant chitinases is largely restricted to those chitinases that contain a noncatalytic, plant-specific, chitin-binding domain (ChBD), also termed as “Hevein domain.” This domain displays a common structural motif of 30–43 residues, rich in glycine and cysteine residues in highly conserved positions and organized around a four-disulfide core. The chapter explains the concepts related to protein–carbohydrate interactions and elaborates the basic techniques for analyzing sugar–Hevein interactions. It also discusses the structure of the Hevein–Saccharide complexes.
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interaction between a minimum Hevein domain and chitooligosaccharides studied by nmr and a novel surface plasmon resonance method
2006Co-Authors: Miquel Vilaperello, Francisco Javier Canada, Jesus Jimenezbarbero, Nuria Aboitiz, Ricardo Gutierrez Gallego, David AndreuAbstract:Introduction Protein-carbohydrate interactions regulate many biologically relevant processes, from fertilization and tissue maturation to tumor metastasis and immune response, and thus are one of the major topics in current biomedical research. In order to gain a major insight into the thermodynamic, kinetic and structural details of such interactions we have recently started a project aimed at defining minimal sugarbinding protein domains and developing suitable tools for studying their interaction with oligosaccharides. As a model system we have chosen the Hevein or chitin-binding domain (CBD) which specifically recognizes chitoligosaccharides and is found in a wide variety of proteins, from plant lectins and chitinases to some antimicrobial peptides. The structure of Hevein bound to chitooligosaccharides was recently described [1]; key residues for the interaction were identified and the C-terminal region seemed not to be directly involved in the recognition process. Accordingly, we decided to study a peptide corresponding to the 32 N-terminal residues of Hevein, to ascertain whether it retained the ability to interact specifically with chitooligosaccharides and elucidate the role of the C-terminal region of this important protein domain (Fig. 1).
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a dynamic perspective on the molecular recognition of chitooligosaccharide ligands by Hevein domains
Carbohydrate Research, 2005Co-Authors: Giorgio Colombo, Juan Luis Asensio, Massimiliano Meli, Javier Sanz Canada, Jesus JimenezbarberoAbstract:The complexes between Hevein and different chitin oligomers, from the di- to the penta-saccharide, are studied through all atom molecular-dynamics simulations. The results for the smaller oligosaccharide complexes show that the carbohydrate is able to move on the surface of the relatively flat binding-pocket of Hevein, therefore occupying different binding subpockets. The pentasaccharide spans all possible intermolecular interactions with the receptor in a simultaneous manner. Statistical analysis methods were also applied in order to define the principal overall motions in the complexes. The oligosaccharide binding can be considered to be defined by a subtle balance between enthalpic and entropic effects, providing the possibility of the existence of multiple binding conformations. This structural and dynamical view parallels the results based on NOE NMR data for the three disaccharide, trisaccharide, and pentasaccharide complexes.
Xaver Baur - One of the best experts on this subject based on the ideXlab platform.
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hla dq8 and the hla dq8 dr4 haplotype are positively associated with the Hevein specific ige immune response in health care workers with latex allergy
The Journal of Allergy and Clinical Immunology, 2002Co-Authors: Hanspeter Rihs, Z Chen, M Raulfheimsoth, Xaver Baur, Reinhold Cremer, Franziska Rueff, D A Moneretvautrin, Thomas BruningAbstract:Abstract Background : Hevein is one of the most important latex allergens affecting health care workers (HCWs). Objective : Because the genetically determined susceptibility is one important factor regulating type I allergy, the association between the Hevein-specific IgE immune response and HLA class II alleles of DQB1 and DRB1, DRB3, DRB4, and DRB5 was studied. Methods : The distribution of HLA-DQB1 and DRB1, DRB3, DRB4, and DRB5 in 269 HCWs with latex allergy, 56 latex-sensitized patients with spina bifida (SB), and 90 nonatopic control subjects under special consideration for Hevein-specific IgE was examined. Results : Seventy percent (189/269) of the HCWs with latex allergy and 39% (22/56) of the latex-sensitized patients with SB had increased Hevein-specific IgE antibody concentrations (>0.35 kU/L). HLA data analysis revealed significantly increased phenotype frequencies for DQB1*0302 (DQ8; 91/189 [48%]) and DRB1*04 (DR4; 102/189 [54%]) in Hevein-positive HCWs with latex allergy compared with the 80 Hevein-negative HCWs with latex allergy (DQB1*0302: 16/80 [20%], corrected P value [P c ] = 7.1 × 10 −4 ; DRB1*04: 23/80 [29%], P c = .01) and with control subjects (DQB1*0302: 16/89 [18%], P c = 1 × 10 −4 ; DRB1*04: 22/90 [24%], P c = 3.2 × 10 −4 ). The DQ8-DR4 haplotype frequency was significantly elevated in HCWs with Hevein-specific IgE antibodies when compared with that in HCWs without Hevein-specific IgE antibodies (47% vs 18%, P c = 5.3 × 10 −4 ) or control subjects (47% vs 18%, P c = 9.6 × 10 −4 ). In contrast, latex-sensitized patients with SB with Hevein-specific IgE antibodies showed an increased but not significant DQB1*0302 frequency (7/22 [32%] vs 2/34 [6%], P = .02, P c = not significant) compared with that seen in those without Hevein-specific IgE antibodies. Conclusion : The DQB1*0302 (DQ8) alone, the DQB1*0302 (DQ8)-DRB1*04 (DR4) haplotype, or both are significantly involved in the Hevein-specific IgE immune response in HCWs with latex allergy. (J Allergy Clin Immunol 2002;110:507-14.)
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class i endochitinase containing a Hevein domain is the causative allergen in latex associated avocado allergy
Clinical & Experimental Allergy, 1999Co-Authors: A Posch, Z Chen, M Raulfheimsoth, Colin H Wheeler, A Flagge, Michael J Dunn, F Papenfuss, Xaver BaurAbstract:Background In the medical literature immunoglobulin (Ig)E-mediated sensitization to avocado is rarely reported. On the other hand, more than 50% of subjects having IgE-mediated natural rubber latex allergy are sensitized to avocado fruit as demonstrated by skin-prick testing and/or specific IgE measurements and about 10–20% report hypersensitivity reactions after ingesting avocado. Objective The underlying pathomechanism of latex-associated avocado allergy is still unknown. The conserved Hevein domain of the major latex allergen proHevein (Hev b 6.01) is a ubiquitous chitin-binding protein structure that can be found in several plant proteins and may be responsible for the observed cross-reactivity between latex and avocado fruit. Methods Chitin-binding avocado proteins (CBAPs) were isolated by affinity-chromatography and their IgE-binding characteristics were studied by immunoblotting using the sera from 15 avocado-sensitized latex patients. Inhibition experiments using isolated Hevein and CBAPs as inhibitor solutions were performed to study the immunological cross-reactivity between both protein species and to assess the role of the CBAPs as mediators in latex-associated avocado allergy. Results In 80% of avocado-sensitized subjects (n = 15), IgE antibodies directed against a 31-kDa allergen were detected by immunoblotting. This IgE-binding protein was identified by protein sequencing to be a class I endochitinase containing a Hevein domain at the N-terminus. Purified native and digested (using simulated gastric fluid) endochitinase were able to completely block all avocado-specific IgE antibodies in six out of seven avocado patients. Conclusions Sensitization to endochitinase class I containing a Hevein domain is the main underlying pathomechanism in latex-mediated avocado allergy.
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identification of Hevein hev b 6 02 in hevea latex as a major cross reacting allergen with avocado fruit in patients with latex allergy
The Journal of Allergy and Clinical Immunology, 1998Co-Authors: Z Chen, Anton Posch, M Raulfheimsoth, Reinhold Cremer, Xaver BaurAbstract:Abstract Background: Recent studies demonstrated that allergy to natural rubber latex is frequently associated with hypersensitivity to avocado fruit. The responsible cross-sensitizing allergen has not been identified. Objective: The purpose of this study was to investigate the cross-reactivity of a latex major allergen, Hevein, with avocado proteins. Methods: Serum samples from 118 health care workers (HCWs) allergic to latex (HCW group) and 78 patients with spina bifida (SB) allergic to latex (SB group) were included in this study. Anti-Hevein and anti-avocado IgE antibodies were measured by enzyme-linked allergosorbent assay. Cross-reactivity of Hevein to avocado proteins was assessed by inhibition of the IgE binding in individual patients' sera containing IgE antibodies to both Hevein and avocado. Results: The prevalence of seropositive IgE antibodies to avocado was found to be strongly associated with the presence of Hevein-specific IgE antibodies in subjects of both groups ( P n = 16). These results indicate that sensitization to avocado in most patients allergic to latex is caused exclusively by IgE-binding epitopes present in Hevein. Results of immunoblots and immunoblot inhibition with 11 serum samples confirmed that a 30-kd protein in avocado was the major IgE-binding component; the IgE-binding reactivity to this protein could be inhibited by Hevein in all sera tested. Conclusion: Hevein is the major cross-reacting allergen with avocado in subjects with latex allergy. (J Allergy Clin Immunol 1998;102:476-81.)
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isolation and identification of Hevein as a major ige binding polypeptide in hevea latex
The Journal of Allergy and Clinical Immunology, 1997Co-Authors: Z Chen, Anton Posch, Christiane Lohaus, M Raulfheimsoth, Helmut E Meyer, Xaver BaurAbstract:Abstract Background: Polypeptides in Hevea latex are known as the major cause of latex type I sensitivities. So far, only a few of them have been characterized. Methods: Proteins with a molecular weight lower than 10 kd in fresh Hevea latex were separated by ultrafiltration and further characterized by liquid chromatography on-line–coupled electrospray mass spectrometry. Hevein in this fraction was then purified by preparative reverse-phase high-performance liquid chromatography and characterized by matrix-assisted laser desorption ionization mass spectrometry and protein sequencing. Skin prick tests, enzyme-linked allergosorbent tests, and inhibition immunoblotting were performed to show the allergenicity of the purified Hevein. Results: Hevein, a 4.7 kd polypeptide, is the predominant component in the fraction with latex proteins of smaller than 10 kd. Specific IgE antibodies to Hevein were detected by enzyme-linked allergosorbent test in 48 of 64 (75%) sera from health care workers allergic to latex and in three of 11 (27%) sera from patients with spina bifida and hypersensitivity reactions to latex. Inhibition immunoblotting demonstrated that the preincubation of 14 sera and a serum pool from patients allergic to latex with purified Hevein completely inhibited IgE binding to the 20 kd protein, which has been recently reported to be a major allergen in latex (proHevein). Skin prick testing showed a positive reaction to Hevein in 17 of 21 (81%) patients with latex allergy. Conclusions: The results clearly demonstrate that Hevein is an important latex allergen, and the IgE-binding capacity of proHevein in latex is mostly attributed to Hevein, the N-terminal domain of proHevein. ( J Allergy Clin Immunol 1997;99:402–9.)
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hla class ii antigens dr4 and dq8 are associated with allergy to Hevein a major allergen of hevea latex
Tissue Antigens, 1997Co-Authors: Hanspeter Rihs, Z Chen, Reinhold Cremer, Xaver BaurAbstract:In this study we investigated the relationship between HLA class II alleles and the IgE-specific immune response to the 4.7 kDa polypeptide Hevein of Hevea brasiliensis, a major latex allergen, 51 individuals with immediate-type latex allergy and 90 controls were examined for the polymorphisms in exon 2 of HLA-DRB1, 3, 4, 5 and DQB1 by sequence-specific oligonucleotide probe typing. 35 (69%) out of 51 latex-sensitized subjects showed positive Hevein-specific IgE values. Analysis of the HLA data among these 35 subjects revealed increased phenotype frequencies for DR4 (22/35, 63%) and DQ8 (18/35, 51%) when compared with those in the 16 Hevein-negative but latex-positive subjects (DR4: 2/16, 13%, p = 0.0009, Pc = 0.047; DQ8: 0/16, p = 0.0003, pc = 0.018) and with healthy controls (DR4: 22/90, 24%, p = 0.00012, pc = 0.013; DQ8: 16/89, 18%, p = 0.0003, pc = 0.036). Finally the DR4-DQ8 haplotype frequency was significantly elevated in Hevein-positives when compared with Hevein-negatives (51% vs. 0, p = 0.0003, pc = 0.034) or controls (51% vs. 18%, p = 0.0002, pc = 0.045) The present data suggest DR4 and DQ8 to be operating jointly as susceptibility factor for the allergy to Hevein.
Adela Rodriguezromero - One of the best experts on this subject based on the ideXlab platform.
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a single amino acid substitution on the surface of a natural Hevein isoform hev b 6 0202 confers different ige recognition
FEBS Letters, 2006Co-Authors: Cesar A Reyeslopez, Alejandra Hernandezsantoyo, Martha Pedrazaescalona, Guillermo Mendoza, Adela RodriguezromeroAbstract:Decreased immune reactivity of isoforms of major allergens has been reported. However, such claims have always been based on experiments with recombinant proteins. This work describes the molecular and physicochemical characterization of a Hevein (Hev b 6.0201) natural isoform (Hev b 6.0202), which is present in rubber latex from Hevea brasiliensis. The isoallergen has a single substitution Asn14Asp, which gives rise to local differences in the surface potential, as observed from the crystal structure presented here. Besides, ELISA inhibition using serum pools of adult and pediatric patients showed reduced IgE-binding capacity (∼27%) with the isoallergen. Overall, these results are relevant to delineate crucial residues involved in this dominant discontinuous epitope.
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insights into a conformational epitope of hev b 6 02 Hevein
Biochemical and Biophysical Research Communications, 2004Co-Authors: Cesar A Reyeslopez, Andres Hernandezarana, Alejandra Hernandezsantoyo, Martha Pedrazaescalona, Guillermo Mendoza, Adela RodriguezromeroAbstract:Abstract Hevein (Hev b 6.02) is a major IgE-binding allergen in natural rubber latex and manufactured products. Both tryptophans (Trp21 and Trp23) of the Hevein molecule were chemically modified with BNPS-skatole (2-nitrophenylsulfenyl-3-methyl-3′-bromoindolenine); derivatized allergen failed to significantly inhibit binding of serum IgE in ELISA assays. Similarly, skin prick tests showed that Hevein-positive patients gave no response with the modified allergen. Dot blot experiments carried out with anti-Hevein mono- and polyclonal antibodies confirmed the importance of Trp21 and Trp23 for antibody-recognition, and demonstrated the specific cross-reactivity of other molecules containing Hevein-like domains. We also report the structure of Hev b 6.02 at an extended resolution (1.5 A) and compare its surface properties around Trp residues with those of similar regions in other allergens. Overall our results indicate that the central part of the protein, which comprises three aromatic and other acidic and polar residues, constitutes a conformational epitope.
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Hevein an allergenic lectin from rubber latex activates human neutrophils oxidative burst
Glycoconjugate Journal, 2001Co-Authors: Enrique Rojas, Adela Rodriguezromero, Paola Llinas, Claudia Hernandez, Marisela Linares, Edgar Zenteno, Ricardo LascurainAbstract:Hevein is an N-acetyl-D-glucosamine (GlcNAc) specific lectin that has been hypothesized to participate in the IgE-mediated allergic reactions in patients with latex allergy. In this work we assessed the specificity and biological effect of Hevein purified from rubber latex on human leukocytes, using epifluorescence microscopy and flow cytometry. Purified human granulocytes were stimulated in vitro with Hevein, and production of oxidative radicals was measured by reduction of nitroblue tetrazolium formazan. Histochemical staining and flow cytometry showed that Hevein recognizes specifically monocytes (CD14+) and neutrophils (CD16+), but not lymphoid cells. Hevein induced oxidative response in purified granulocytes; this effect was 1.3-1.5-fold higher than the effect observed with the lectin WGA (wheat germ agglutinin), or other lectins with different sugar specificity. The induced reactions and cellular recognition by Hevein were inhibited with GlcNAc and its oligomers; as well as by glycoproteins containing tri-and tetra-antennary N-glycosydically linked glycans. Our findings suggest that neutrophils are the main target for latex Hevein; this lectin induces production of oxidative radicals, which seem to play an important role in tissue damage during latex allergy.
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nmr investigations of protein carbohydrate interactions refined three dimensional structure of the complex between Hevein and methyl β chitobioside
Glycobiology, 1998Co-Authors: Juan Luis Asensio, Francisco Javier Canada, Marta Bruix, Adela Rodriguezromero, Carlos Gonzalez, Noureddine Khiar, Jesus JimenezbarberoAbstract:The specific interaction of Hevein with GlcNAc-containing oligosaccharides has been analyzed by1H-NMR spectroscopy. The association constants for the binding of Hevein to a variety of ligands have been estimated from1H-NMR titration experiments. The association constants increase in the order GlcNAc-alpha(1-->6)-Man < GlcNAc < benzyl-beta-GlcNAc < p-nitrophenyl-beta-GlcNAc < chitobiose < p-nitrophenyl-beta-chitobioside < methyl-beta-chitobioside < chitotriose. Entropy and enthalpy of binding for different complexes have been obtained from van't Hoff analysis. The driving force for the binding process is provided by a negative DeltaH0which is partially compensated by negative DeltaS0. These negative signs indicate that hydrogen bonding and van der Waals forces are the major interactions stabilizing the complex. NOESY NMR experiments in water solution provided 475 accurate protein proton-proton distance constraints after employing the MARDIGRAS program. In addition, 15 unambiguous protein/carbohydrate NOEs were detected. All the experimental constraints were used in a refinement protocol including restrained molecular dynamics in order to determine the highly refined solution conformation of this protein-carbohydrate complex. With regard to the NMR structure of the free protein, no important changes in the protein nOe's were observed, indicating that carbohydrate-induced conformational changes are small. The average backbone rmsd of the 20 refined structures was 0.055 nm, while the heavy atom rmsd was 0.116 nm. It can be deduced that both hydrogen bonds and van der Waals contacts confer stability to the complex. A comparison of the three-dimensional structure of Hevein in solution to those reported for wheat germ agglutinin (WGA) and Hevein itself in the solid state has also been performed. The polypeptide conformation has also been compared to the NMR-derived structure of a smaller antifungical peptide, Ac-AMP2.
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the interaction of Hevein with n acetylglucosamine containing oligosaccharides solution structure of Hevein complexed to chitobiose
FEBS Journal, 1995Co-Authors: Juan Luis Asensio, Francisco Javier Canada, Marta Bruix, Adela Rodriguezromero, Jesus JimenezbarberoAbstract:The three-dimensional structure of Hevein, a small protein isolated from the latex of Hevea brasiliensis (rubber tree), in water solution has been obtained by using 1H-NMR spectroscopy and dynamic simulated annealing calculations. The average root-mean-square deviation (rmsd) of the best 20 refined structures generated using DIANA prior to simulated annealing was 0.092 nm for the backbone atoms and 0.163 nm for all heavy atoms (residues 3-41). The specific interaction of Hevein with N-acetylglucosamine-containing oligosaccharides has also been analyzed by 1H-NMR. The association constants, Ka, for the binding of Hevein to GlcNAc, chitobiose [GlcNAc-beta(1-->4)-GlcNAc], chitotriose [GlcNAc-beta(1-->4)-GlcNAc-beta(1-->4)-GlcNAc], and GlcNAc-alpha(1-->6)-Man have been estimated from 1H-NMR titration experiments. Since the measured Ka values for chitobiose binding are almost identical with and without calcium ions, it is shown that these cations are not required for sugar binding. The association increases in the order GlcNAc-alpha(1-->6)-Man 6)-Man can be explained by favourable stacking of the second beta-linked GlcNAc moiety and Trp21.
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five disulfide bridges stabilize a Hevein type antimicrobial peptide from the bark of spindle tree euonymus europaeus l
FEBS Letters, 2002Co-Authors: Karolien Van Den Bergh, Jo Van Damme, Jozef Coosemans, Els J M Van Damme, Willy J PeumansAbstract:A small 45 amino acid residue antifungal polypeptide was isolated from the bark of spindle tree (Euonymus europaeus L.). Though the primary structure of this so-called E. europaeus chitin-binding protein or Ee-CBP is highly similar to the Hevein domain, it distinguishes itself from most previously identified Hevein-type antimicrobial peptides (AMP) by the presence of two extra cysteine residues that form an extra disulfide bond. Due to these five disulfide bonds Ee-CBP is a remarkably stable protein. Agar diffusion and microtiterplate assays demonstrated that Ee-CBP is a potent antimicrobial protein. IC50-values as low as 1 μg/ml were observed for the fungus Botrytis cinerea. Comparative assays further demonstrated that Ee-CBP is a stronger inhibitor of fungal growth than Ac-AMP2 from Amaranthus caudatus seeds, which is considered one of the most potent antifungal Hevein-type plant proteins.
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the primary structure of stinging nettle urtica dioica agglutinin a two domain member of the Hevein family
FEBS Letters, 1992Co-Authors: Jaap J Beintema, Willy J PeumansAbstract:The primary structure of stinging nettle (Urtica dioica) agglutinin has been determined by sequence analysis of peptides obtained from three overlapping proteolytic digests. The sequence of 80 residues consists of two Hevein-like domains with the same spacing of half-cystine residues and several other conserved residues as observed earlier in other proteins with Hevein-like domains. The hinge region between the two domains is four residues longer than those between the four domains in cereal lectins like wheat germ agglutinin.
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Hevein an antifungal protein from rubber tree hevea brasiliensis latex
Planta, 1991Co-Authors: Jan Van Parijs, Willem F Broekaert, Irwin J Goldstein, Willy J PeumansAbstract:Several chitin-binding proteins were isolated from the “bottom fraction” of Hevea brasiliensis (Mull.) Arg. latex. One of these chitin-binding proteins is Hevein, a small monomeric protein which strongly resembles the lectin from stinging nettle (Urtica dioica L.). Like the latter, Hevein showed strong antifungal activity against several fungi in vitro. The possible involvement of this protein in the defense against invasion by potentially pathogenic fungi is discussed.