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Avadhesha Surolia - One of the best experts on this subject based on the ideXlab platform.
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pattern recognition in Legume Lectins to extrapolate amino acid variability to sugar specificity
Advances in Experimental Medicine and Biology, 2015Co-Authors: Nisha Jayaprakash Grandhi, Ashalatha Sreshty Mamidi, Avadhesha SuroliaAbstract:Biologic recognition is critical for cell growth, its differentiation and a number of other physiological processes. Lectin carbohydrate interactions mediate and regulate these cellular processes. Hence they have attracted a lot of attention recently. Amongst Lectins, those from Legumes are the most widely studied. Herein, we report our findings based on the influence of amino acid constitution in maintaining the structural integrity and sugar binding specificity of these Lectins. We have implemented a pattern recognition system represented by heatmaps and clustergrams. Percentage identity and amino acid composition of 46 Legume Lectins were computed to distinguish between different sugar specific Lectins and derive a consensus amongst them. A clear distinction was apparent between different monosaccharide binding groups based on their composition, sequence identities and the specific amino residues in their combining sites.
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Peanut agglutinin, a lectin with an unusual quaternary structure and interesting ligand binding properties
Crystallography Reviews, 2007Co-Authors: S. Kundhavai Natchiar, Avadhesha Surolia, Kaza Suguna, M VijayanAbstract:Lectins are multivalent proteins which play their biological role through the ability to specifically bind different carbohydrate structures. This ability has also led to their myriad applications. They occur in all forms of life. Among plant Lectins, those from leguminous plants constitute the most thoroughly studied family. Most of the well-characterized Legume Lectins can be classified as mannose (Man)/glucose (Glc) specific or galactose (Gal)/N-acetylgalactosamine (GalNAc) specific. Tetrameric, non-glycosylated peanut agglutinin (PNA) is the most thoroughly investigated member of the Gal/GalNAc specific family of Legume Lectins. Its structure indicated that open quaternary association also needed to be considered when dealing with multimeric proteins. The structure also helped to establish Legume Lectins as a family of proteins in which small alterations in essentially the same tertiary structure lead to large changes in quaternary association. It provides an explanation for the exclusive specificity ...
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determinants of quaternary association in Legume Lectins
Protein Science, 2004Co-Authors: K V Brinda, Nivedita Mitra, Avadhesha Surolia, S VishveshwaraAbstract:It is well known that the sequence of amino acids in proteins code for its tertiary structure. It is also known that there exists a relationship between sequence and the quaternary structure of proteins. The question addressed here is whether the nature of quaternary association can be predicted from the sequence, similar to the three-dimensional structure prediction from the sequence. The class of proteins called Legume Lectins is an interesting model system to investigate this problem, because they have very high sequence and tertiary structure homology, with diverse forms of quaternary association. Hence, we have used Legume Lectins as a probe in this paper to (1) gain novel insights about the relationship between sequence and quaternary structure; (2) identify the sequence motifs that are characteristic of a given type of quaternary association; and (3) predict the quaternary association from the sequence motif.
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Legume Lectins a paradigm in quaternary structure variations arising from similar tertiary structural fold
2002Co-Authors: Nivedita Mitra, V R Srinivas, Avadhesha SuroliaAbstract:Proteins belonging to the Legume lectin family are characterized by similarity in their tertiary structures and differences in their modes of quatemary association which are brought about by minor variations in amino acid sequences. It is observed that differences in the modes of their association cause them to adopt different stabilities and folding patterns as studied by differential scanning calorimetry and isothemwal denaturation experiments. The proteins with the canonical and the handshake mode of association show a two-state denaturation profile but differ in their calorimetric to van't Hoff enthalpy ratio, thus indicating that these proteins unfold in slightly different ways. In this class of proteins we also see a homotetrameric protein like the peanut agglutinin, which neither shows a D 2 nor a four-fold symmetry This kind of unusual structure confers upon it an unusual folding pathway where the presence of a partially unfolded and active monomeric intermediate is observed. Thus we see that these proteins are good specimens to study the effects of minor alterations in their sequences on their oligomeric association.
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Legume lectin family, the 'natural mutants of the quaternary state', provide insights into the relationship between protein stability and oligomerization.
Biochimica et Biophysica Acta, 2001Co-Authors: V R Srinivas, Nivedita Mitra, Chittoor P. Swaminathan, G. Bhanuprakash Reddy, Nisar Ahmad, Avadhesha SuroliaAbstract:Legume Lectins family of proteins, despite having the same 'jelly roll' tertiary structural fold at monomeric level, exhibit considerable variation in their quaternary structure arising out of small changes in their sequence. Nevertheless, their folding behavior and stability correlates very well with their patterns of assembly into dimers and tetramers. A conservation of their fold during evolution, its wide distribution in many protein families together with the availability of structural information on them make them interesting as proteins to explore the effect of inter- versus intra-subunit interactions in the stability of multimeric proteins. Additionally, as 'natural mutants' of quaternary association, proteins of Legume lectin family provide interesting paradigms for studies addressing the effect of subunit oligomerization on the stability, folding and function as well as the evolution of multimeric structures.
Benildo Sousa Cavada - One of the best experts on this subject based on the ideXlab platform.
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reviewing mimosoideae Lectins a group of under explored Legume Lectins
International Journal of Biological Macromolecules, 2020Co-Authors: Benildo Sousa Cavada, Vinicius Jose Silva Osterne, Messias Vital Oliveira, Vanir Reis Pintojunior, Mayara Torquato Lima Silva, Alfa Umaro Bari, Lara Dias Lima, Claudia Figueiredo Lossio, Kyria S NascimentoAbstract:Abstract Lectins are proteins capable of specific and reversible binding to mono- and/or oligosaccharides, and within this group, Legume Lectins are the most studied. However, most of these studies focus on the Papilionoideae subfamily, with Caesalpinioideae and Mimosoideae Lectins being significantly less explored in the literature. The Mimosoideae subfamily consists of at least 79 genera and 3275 species, but, to date, only about 14 Lectins have been purified, a fact which shows the lack of studies for this group. Based on their purification protocols, as well as physicochemical and structural properties, Mimosoideae Lectins are very heterogeneous. Despite the few studies, a wide variety of biological activities have been tested, including, for example, inflammatory, anticancer, antibacterial, and antifungal. In this context, the present review aims to summarize the available data regarding the purification, physicochemical and structural properties, as well as biological activities, of Lectins extracted from plants of the Mimosoideae subfamily in order to bring more insight to researchers interested in further exploring the potential of these molecules.
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One century of ConA and 40 years of ConBr research: A structural review.
International Journal of Biological Macromolecules, 2019Co-Authors: Benildo Sousa Cavada, Vinicius Jose Silva Osterne, Messias Vital Oliveira, Mayara Torquato Lima Silva, Claudia Figueiredo Lossio, Vanir Reis Pinto-junior, Rodrigo B. Leal, Kyria S NascimentoAbstract:Abstract Lectins are proteins that can bind specifically and reversibly to carbohydrates. This capacity gives Lectins multiple biological roles and biotechnological applications. Although Lectins can be found in all organisms, plant Lectins, especially Legume Lectins, are undoubtedly the most thoroughly studied. Among Legume Lectins, the lectin from Canavalia ensiformis (ConA) and Canavalia brasiliensis (ConBr), both from Diocleinae subtribe, are two of the most well-known Lectins. It has been 100 years since the first report of ConA and 40 years since the first report of ConBr, making 2019 an important year for lectinology. Structural data of these Lectins in combination with biological activity tests clearly indicate that even a small shift in amino acid sequence can affect the tertiary and quaternary structures, consequently affecting the biological activity of these proteins. It is in this context that the present paper aims to review the structural data of ConA and ConBr, focusing on the primary structure, crystallography, tertiary and quaternary structures of these Lectins, as well as their binding sites. This paper also expands the structural data by employing molecular dynamics to evaluate carbohydrate-binding properties and structural stability. It is anticipated that these data will increase knowledge about the structure-function relationships of these proteins.
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Molecular Modeling of Lectin-Like Protein from Acacia farnesiana Reveals a Possible Anti-Inflammatory Mechanism in Carrageenan-Induced Inflammation
BioMed Research International, 2013Co-Authors: Vanessa Erika Ferreira Abrantes, Benildo Sousa Cavada, Bruno A.m. Rocha, R.b. Nobrega, J.c. Silva-filho, Claudener S. Teixeira, Carlos Alberto De Almeida Gadelha, Sérgio H. Ferreira, Jozi G. Figueiredo, Tatiane Santi-gadelhaAbstract:Acacia farnesiana lectin-like protein (AFAL) is a chitin-binding protein and has been classified as phytohaemagglutinin from Phaseolus vulgaris (PHA). Legume Lectins are examples for structural studies, and this family of proteins shows a remarkable conservation in primary, secondary, and tertiary structures. Lectins have ability to reduce the effects of inflammation caused by phlogistic agents, such as carrageenan (CGN). This paper explains the anti-inflammatory activity of AFAL through structural comparison with anti-inflammatory Legume Lectins. The AFAL model was obtained by molecular modeling and molecular docking with glycan and carrageenan were performed to explain the AFAL structural behavior and biological activity. Pisum sativum lectin was the best template for molecular modeling. The AFAL structure model is folded as a β sandwich. The model differs from template in loop regions, number of β strands and carbohydrate-binding site. Carrageenan and glycan bind to different sites on AFAL. The ability of AFAL binding to carrageenan can be explained by absence of the sixth β-strand (posterior β sheets) and two β strands in frontal region. AFAL can inhibit pathway inflammatory process by carrageenan injection by connecting to it and preventing its entry into the cell and triggers the reaction.
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interactions between indole 3 acetic acid iaa with a lectin from canavalia maritima seeds reveal a new function for Lectins in plant physiology
Biochimie, 2013Co-Authors: Plinio Delatorre, Kyria S Nascimento, Alexandre Holanda Sampaio, B A M Rocha, Celso Shiniti Nagano, R.b. Nobrega, Carlos Alberto De Almeida Gadelha, J C Silvafilho, Tatiane Santigadelha, Benildo Sousa CavadaAbstract:Abstract Indole-3- a cetic a cid (IAA) bound is considered a storage molecule and is inactive. However, some studies have proposed an additional possible regulatory mechanism based on the ability of Lectins to form complexes with IAA. We report the first crystal structure of ConM in complex with IAA at 2.15 A resolution. Based on a tetrameric model of the complex, we hypothesize how the lectin controls the availability of IAA during the early seedling stages, indicating a possible new physiological role for these proteins. A free indole group is also bound to the protein. The ConM interaction with different forms of IAA is a strategy to render the phytohormone unavailable to the cell. Thus, this new physiological role proposed for Legume Lectins might be a novel mechanism by which IAA levels are decreased in addition to the destruction and formation of new complexes in the later stages of seed germination.
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identification of a new quaternary association for Legume Lectins
Journal of Structural Biology, 2008Co-Authors: Frederico Bruno Mendes Batista Moreno, Benildo Sousa Cavada, G A Bezerra, Taiana M Oliveira, Daiana Evelin Martil, Magno M Vicoti, Jose Ramon Beltran Abrego, Walter Filgueira De AzevedoAbstract:Abstract Lotus tetragonolobus lectin (LTA) is a fucose-specific Legume lectin. Although several studies report a diverse combination of biological activities for LTA, little is known about the mechanisms involved in l -fucosyl oligosaccharide recognition. The crystal structure of LTA at 2.0 A resolution reveals a different Legume lectin tetramer. Its structure consists of a homotetramer composed of two back-to-back GS4-like dimers arranged in a new mode, resulting in a novel tetramer. The LTA N -linked carbohydrate at Asn4 and the unusual LTA dimer–dimer interaction are related to its particular mode of tetramerization. In addition, we used small angle X-ray scattering to investigate the quaternary structure of LTA in solution and to compare it to the crystalline structure. Although the crystal structure of LTA has revealed a conserved metal-binding site, its l -fucose-binding site presents some punctual differences. Our investigation of the new tetramer of LTA and its fucose-binding site is essential for further studies related to cross-linking between LTA and complex divalent l -fucosyl carbohydrates.
M Vijayan - One of the best experts on this subject based on the ideXlab platform.
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Peanut agglutinin, a lectin with an unusual quaternary structure and interesting ligand binding properties
Crystallography Reviews, 2007Co-Authors: S. Kundhavai Natchiar, Avadhesha Surolia, Kaza Suguna, M VijayanAbstract:Lectins are multivalent proteins which play their biological role through the ability to specifically bind different carbohydrate structures. This ability has also led to their myriad applications. They occur in all forms of life. Among plant Lectins, those from leguminous plants constitute the most thoroughly studied family. Most of the well-characterized Legume Lectins can be classified as mannose (Man)/glucose (Glc) specific or galactose (Gal)/N-acetylgalactosamine (GalNAc) specific. Tetrameric, non-glycosylated peanut agglutinin (PNA) is the most thoroughly investigated member of the Gal/GalNAc specific family of Legume Lectins. Its structure indicated that open quaternary association also needed to be considered when dealing with multimeric proteins. The structure also helped to establish Legume Lectins as a family of proteins in which small alterations in essentially the same tertiary structure lead to large changes in quaternary association. It provides an explanation for the exclusive specificity ...
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variability in quaternary association of proteins with the same tertiary fold a case study and rationalization involving Legume Lectins
Proteins, 1999Co-Authors: Moses M Prabu, K Suguna, M VijayanAbstract:Legume Lectins constitute a family of proteins in which small alterations arising from sequence variations in essentially the same tertiary structure lead to large changes in quaternary association. All of them are dimers or tetramers made up of dimers. Dimerization involves side-by-side or back-to-back association of the flat six-membered beta-sheets in the protomers. Variations within these modes of dimerization can be satisfactorily described in terms of angles defining the mutual disposition of the two subunits. In all tetrameric Lectins, except peanut lectin, oligomerization involves the back-to-back association of side-by-side dimers. An attempt has been made to rationalize the observed modes of oligomerization in terms of hydrophobic surface area buried on association, interaction energy and shape complementarity, by constructing energy minimised models in each of which the subunit of one Legume lectin is fitted in the quaternary structure of another. The results indicate that all the three indices favor and, thus, provide a rationale for the observed arrangements. However, the discrimination provided by buried hydrophobic surface area is marginal in a few instances. The same is true, to a lesser extent, about that provided by shape complementarity. The relative values of interaction energy turns out to be a still better discriminator than the other two indices. Variability in the quaternary association of homologous proteins is a widely observed phenomenon and the present study is relevant to the general problem of protein folding.
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molecular basis of recognition by gal galnac specific Legume Lectins influence of glu 129 on the specificity of peanut agglutinin pna towards c2 substituents of galactose
Glycobiology, 1998Co-Authors: Vivek Sharma, M Vijayan, V R Srinivas, P Adhikari, Avadhesha SuroliaAbstract:The ability to discriminate between galactose and N-acetylga-lactosamine, observed in some Lectins, is crucial for their biological activity as well as their usefulness as tools in biology and medicine. However, the molecular basis of differential binding of Lectins to these two sugars is poorly understood. Peanut agglutinin (PNA) is one of the few galactose-specific Legume Lectins which does not bind N-acetylgalactosamine at all and is, therefore, ideal for the study of the basis of specificity towards C-2 substituted derivatives of galactopyranosides. Examination of the three-dimensional structure of PNA in complex with lactose revealed the presence of both a longer loop and bulkier residues in the region surrounding the C-2 hydroxyl of the galactopyranoside ring, which can sterically prevent the accommodation of a bulky substituent in this position. One such residue, is a glutamic acid at position 129 which protrudes into the binding site and perhaps directly obstructs any substitution at the C-2 position. Two mutants in bacterially expressed PNA were therefore constructed. These were E129D and E129A, in which Glu129 was replaced by Asp and Ala, respectively. The specificity of the mutants for galactose, galactosamine, and N-acetylgalactosamine was examined through observing the inhibition of hemagglutination and binding of the lectin to immobilized asialofetuin. The results showed that the affinity of E129A and E129D for C-2-substituted derivatives of the galactose varies. The mutant E129D showed significant binding towards N-acetylgalactosamine, suggesting that the residue Glu 129 is crucial in imparting exclusive galactose-specificity upon PNA. This study not only attempts to provide an explanation for the inability of PNA to accommodate C-2-substituted derivatives at its primary subsite, but also seeks to present a basis for engineering Lectins with altered specificities.
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Molecular basis of recognition by Gal/GalNAc specific Legume Lectins: Influence of Glu 129 on the specificity of peanut agglutinin (PNA) towards C2-substituents of galactose
Glycobiology, 1998Co-Authors: Vivek Sharma, M Vijayan, V R Srinivas, P Adhikari, Avadhesha SuroliaAbstract:The ability to discriminate between galactose and N-acetylga-lactosamine, observed in some Lectins, is crucial for their biological activity as well as their usefulness as tools in biology and medicine. However, the molecular basis of differential binding of Lectins to these two sugars is poorly understood. Peanut agglutinin (PNA) is one of the few galactose-specific Legume Lectins which does not bind N-acetylgalactosamine at all and is, therefore, ideal for the study of the basis of specificity towards C-2 substituted derivatives of galactopyranosides. Examination of the three-dimensional structure of PNA in complex with lactose revealed the presence of both a longer loop and bulkier residues in the region surrounding the C-2 hydroxyl of the galactopyranoside ring, which can sterically prevent the accommodation of a bulky substituent in this position. One such residue, is a glutamic acid at position 129 which protrudes into the binding site and perhaps directly obstructs any substitution at the C-2 position. Two mutants in bacterially expressed PNA were therefore constructed. These were E129D and E129A, in which Glu129 was replaced by Asp and Ala, respectively. The specificity of the mutants for galactose, galactosamine, and N-acetylgalactosamine was examined through observing the inhibition of hemagglutination and binding of the lectin to immobilized asialofetuin. The results showed that the affinity of E129A and E129D for C-2-substituted derivatives of the galactose varies. The mutant E129D showed significant binding towards N-acetylgalactosamine, suggesting that the residue Glu 129 is crucial in imparting exclusive galactose-specificity upon PNA. This study not only attempts to provide an explanation for the inability of PNA to accommodate C-2-substituted derivatives at its primary subsite, but also seeks to present a basis for engineering Lectins with altered specificities.
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Carbohydrate specificity and quaternary association in basic winged bean lectin: X-ray analysis of the lectin at 2.5 A resolution.
Journal of Molecular Biology, 1998Co-Authors: Moses M Prabu, Avadhesha Surolia, Vivek Sharma, M Vijayan, Rajan Sankaranarayanan, Kamal D. Puri, Kaza SugunaAbstract:Abstract The structure of basic Winged Bean Agglutinin (WBAI) with two dimeric molecules complexed with methyl-α- d -galactopyranoside in the asymmetric unit, has been determined by the molecular replacement method and refined with 2.5 A X-ray intensity data. The polypeptide chain of each monomer has the characteristic Legume lectin tertiary fold. The structure clearly defines the lectin-carbohydrate interactions. It reveals how the unusually long variable loop in the binding region endows the lectin with its characteristic sugar specificity. The lectin forms non-canonical dimers of the type found in Erythrina corallodendron lectin (EcorL) even though glycosylation, unlike in EcorL, does not prevent the formation of canonical dimers. The structure thus further demonstrates that the mode of dimerisation of Legume Lectins is not necessarily determined by the covalently bound carbohydrate but is governed by features intrinsic to the protein. The present analysis and our earlier work on peanut lectin (PNA), show that Legume Lectins are a family of proteins in which small alterations in essentially the same tertiary structure lead to wide variations in quaternary association. A relationship among the non-canonical modes of dimeric association in Legume Lectins is presented.
Pierre Rouge - One of the best experts on this subject based on the ideXlab platform.
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Lectin Receptor Kinases in Plants
Critical Reviews in Plant Sciences, 2020Co-Authors: Annick Barre, Christine Hervé, Bernard Lescure, Pierre RougeAbstract:Referee: Dr. Philip Becraft, Zoology and Genetics/Agronomy Depts., 2116 Molecular Building, lowa State University, Ames, IA 50011 Forty-two lectin receptor kinase (lecRK)-related sequences and nine related soluble Legume lectin sequences were identified in the Arabidopsis thaliana genome. The genes are scattered as a single or gathered copies at different loci throughout the five chromosomes, and four predicted lecRK probably correspond to pseudogenes. Both structural alignments and molecular modeling revealed striking similarities between the lectinlike domain of lecRK, and related A. thaliana soluble Lectins and Legume Lectins. The hydrophobic cavity is extremely conserved, whereas most of the residues forming the monosaccharide-binding site and the bivalent cation-binding site of Legume Lectins are poorly conserved. LecRK should be unable to bind the simple sugars usually recognized by genuine Legume Lectins. Molecular modeling of the kinase domain suggests that, except for two apparently inactive rece...
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characterization of ige binding epitopes of peanut arachis hypogaea pna lectin allergen cross reacting with other structurally related Legume Lectins
Molecular Immunology, 2010Co-Authors: Pierre Rouge, Raphael Culerrier, Claude Granier, Fabienne Rance, Annick BarreAbstract:Abstract Sera from peanut allergic patients contain IgE that specifically interact with the peanut lectin PNA and other closely related Legume Lectins like LcA from lentil, PsA from pea and PHA from kidney bean. The IgE-binding activity of PNA and Legume Lectins was assessed by immunoblotting, surface plasmon resonance (SPR) and ELISA measurements, using sera from peanut allergic patients as a IgE source. This IgE-binding cross-reactivity most probably depends on the occurrence of structurally related epitopes that have been identified on the molecular surface of PNA and other Legume Lectins. These epitopes definitely differ from those responsible for the allergenicity of the major allergens Ara h 1, Ara h 2 and Ara h 3, also recognized by the IgE-containing sera of peanut allergic patients. Peanut lectin PNA and other Legume Lectins have been characterized as potential allergens for patients allergic to edible Legume seeds. However, the clinical significance of the lectin–IgE interaction has to be addressed.
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leaves of the lamiaceae species glechoma hederacea ground ivy contain a lectin that is structurally and evolutionary related to the Legume Lectins
Plant Journal, 2003Co-Authors: Weifang Wang, Pierre Rouge, Willy J. Peumans, Claire Rossi, Paul Proost, Jianping Chen, Els J M Van DammeAbstract:Summary A novel lectin has been isolated and cloned from leaves of Glechoma hederacea (ground ivy), a typical representative of the plant family Lamiaceae. Biochemical analyses indicated that the G. hederacea agglutinin (Gleheda) is a tetrameric protein consisting of four subunits pairwise linked through an interchain disulphide bridge and exhibits a preferential specificity towards N-acetylgalactosamine. Cloning of the corresponding gene and molecular modeling of the deduced sequence demonstrated that Gleheda shares high sequence similarity with the Legume Lectins and exhibits the same overall fold and three-dimensional structure as the classical Legume Lectins. The identification of a soluble and active Legume lectin ortholog in G. hederacea not only indicates that the yet unclassified Lamiaceae Lectins belong to the same lectin family as the Legume Lectins, but also sheds a new light on the specificity, physiological role and evolution of the classical Legume Lectins.
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classification of plant Lectins in families of structurally and evolutionary related proteins
Advances in Experimental Medicine and Biology, 2001Co-Authors: Willy J. Peumans, Annick Barre, Jo Van Damme, Pierre RougeAbstract:The majority of plant Lectins can be classified in seven families of structurally and lutionary related proteins. Within a given lectin family most but not necessarily all mbers are built up of protomers with a similar primary structure and overall 3-D fold. The rall structure of the native Lectins is not only determined by the structure of the protomers depends also on the degree of oligomerization and in some cases on the post-nslational processing of the lectin precursors. In general, lectin families are fairly homogeneous for what concerns the overall cificity of the individualLectins, which illustrates that the 3-D structure of the binding site been conserved during evolution. In the case of the jacalin-related Lectins the occurrence a mannose-and galactose-binding subfamily can be explained by the fact that a post-nslational cleavage of the protomers (of the galactose-binding subfamily) yields a slightly red binding site. Unlike the other families, the Legume Lectins display a wide range of cificites, which is clearly reflected in the occurrence of sugar-binding sites with a erent 3-D structure.
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Characterization of the Arabidopsis lecRK-a genes: members of a superfamily encoding putative receptors with an extracellular domain homologous to Legume Lectins
Plant Molecular Biology, 1999Co-Authors: Christine Hervé, Annick Barre, Pierre Rouge, Jérome Serres, Patrick Dabos, Hervé Canut, Bernard LescureAbstract:An Arabidopsis cDNA clone that defines a new class of plant serine/threonine receptor kinases was found to be a member of a family of four clustered genes (lecRK-a1–a4) which have been cloned, sequenced and mapped on chromosome 3. This family belongs to a large superfamily encoding putative receptors with an extracellular domain homologous to Legume Lectins and appears to be conserved at least among dicots. In the Columbia ecotype only the lecRK-a1 and perhaps the lecRK-a3 gene is functional, since lecRK-a2 is disrupted by a Ty-copia retroelement and lecRK-a4 contains a frameshift mutation. Structural analysis of the lecRK-a1 and lecRK-a3 deduced amino-acid sequences suggests that the lectin domain is unlikely to be involved in binding monosaccharides but could interact with complex glycans and/or with hydrophobic ligands. Immunodetection of lecRK gene products in plasma membranes purified by free-flow electrophoresis showed that the lecRK-a proteins are probably highly glycosylated integral plasma membrane components.
Plinio Delatorre - One of the best experts on this subject based on the ideXlab platform.
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Structural characterization of a Vatairea macrocarpa lectin in complex with a tumor-associated antigen: A new tool for cancer research.
The International Journal of Biochemistry & Cell Biology, 2016Co-Authors: Bruno L Sousa, Kyria S Nascimento, Prashant Kumar, Ronniery Ilario Pereira, Plinio Delatorre, J.c. Silva-filho, Melissa A. Graewert, Rodrigo Maranguape Silva Da Cunha, Gustavo Arruda Bezerra, Kristina Djinović-carugoAbstract:Abstract Legume Lectins are the most thoroughly studied group of Lectins and have been widely linked to many pathological processes. Their use as immunohistochemistry markers for cell profiling and cancer diagnosis have made these molecules important tools for immunological studies and have stimulated the prospection and characterization of new Lectins. The crystal structures of a recombinant seed lectin from Vatairea macrocarpa (rVML) and its complexes with GalNAcα1-O-Ser, GalNAc and α-lactose, have been determined at 1.90, 1.97, 2.70 and 1.83 A resolution, respectively. Small angle X-ray scattering and calorimetry assays have confirmed the same pH stable oligomerization pattern and binding profiles proposed for its wild-type counterpart. In silico analyzes have explored the potential of this recombinant lectin as new tool for cancer research through a comparative profile with other Legume Lectins widely used for cancer diagnosis and prognosis. The results suggest the recognition of specific epitopes exhibited on different cancer cells as a process that relies on the disposition of hydrophobic clusters and charged regions around the lectin carbohydrate-binding site, favouring the anchorage of different groups in the antigen boundaries, highlighting the different potential of each analyzed lectin. In conclusion, the experimental results and comparative analysis show that rVML is as a promising tool for cancer research, able to bind with high affinity specific tumor-associated antigens, highly stable and easily produced.
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high resolution structure of a new tn antigen binding lectin from vatairea macrocarpa and a comparative analysis of tn binding Legume Lectins
The International Journal of Biochemistry & Cell Biology, 2015Co-Authors: Bruno L Sousa, Jose Caetano Silva Filho, Prashant Kumar, Ronniery Ilario Pereira, Andrzej łyskowski, B A M Rocha, Plinio Delatorre, G A Bezerra, Celso Shiniti Nagano, Karl GruberAbstract:Abstract Plant Lectins have been studied as histological markers and promising antineoplastic molecules for a long time, and structural characterization of different Lectins bound to specific cancer epitopes has been carried out successfully. The crystal structures of Vatairea macrocarpa (VML) seed lectin in complex with GalNAc-α- O -Ser (Tn antigen) and GalNAc have been determined at the resolution of 1.4 A and 1.7 A, respectively. Molecular docking analysis of this new structure and other Tn-binding Legume Lectins to O -mucin fragments differently decorated with this antigen provides a comparative binding profile among these proteins, stressing that subtle alterations that may not influence monosaccharide binding can, nonetheless, directly impact the ability of these Lectins to recognize naturally occurring antigens. In addition to the specific biological effects of VML, the structural and binding similarities between it and other Lectins commonly used as histological markers ( e.g. , VVLB4 and SBA) strongly suggest VML as a candidate tool for cancer research.
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interactions between indole 3 acetic acid iaa with a lectin from canavalia maritima seeds reveal a new function for Lectins in plant physiology
Biochimie, 2013Co-Authors: Plinio Delatorre, Kyria S Nascimento, Alexandre Holanda Sampaio, B A M Rocha, Celso Shiniti Nagano, R.b. Nobrega, Carlos Alberto De Almeida Gadelha, J C Silvafilho, Tatiane Santigadelha, Benildo Sousa CavadaAbstract:Abstract Indole-3- a cetic a cid (IAA) bound is considered a storage molecule and is inactive. However, some studies have proposed an additional possible regulatory mechanism based on the ability of Lectins to form complexes with IAA. We report the first crystal structure of ConM in complex with IAA at 2.15 A resolution. Based on a tetrameric model of the complex, we hypothesize how the lectin controls the availability of IAA during the early seedling stages, indicating a possible new physiological role for these proteins. A free indole group is also bound to the protein. The ConM interaction with different forms of IAA is a strategy to render the phytohormone unavailable to the cell. Thus, this new physiological role proposed for Legume Lectins might be a novel mechanism by which IAA levels are decreased in addition to the destruction and formation of new complexes in the later stages of seed germination.
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Structural basis for both pro- and anti-inflammatory response induced by mannose-specific Legume lectin from Cymbosema roseum.
Biochimie, 2011Co-Authors: Bruno A.m. Rocha, Plinio Delatorre, Taiana M Oliveira, Raquel Guimaraes Benevides, Alana De Freitas Pires, Albertina Antonielly Sydney De Sousa, Luis A. G. Souza, Ana Maria Sampaio Assreuy, Henri Debray, Walter Filgueira De AzevedoAbstract:Abstract Legume Lectins, despite high sequence homology, express diverse biological activities that vary in potency and efficacy. In studies reported here, the mannose-specific lectin from Cymbosema roseum (CRLI), which binds N-glycoproteins, shows both pro-inflammatory effects when administered by local injection and anti-inflammatory effects when by systemic injection. Protein sequencing was obtained by Tandem Mass Spectrometry and the crystal structure was solved by X-ray crystallography using a Synchrotron radiation source. Molecular replacement and refinement were performed using CCP4 and the carbohydrate binding properties were described by affinity assays and computational docking. Biological assays were performed in order to evaluate the lectin edematogenic activity. The crystal structure of CRLI was established to a 1.8 A resolution in order to determine a structural basis for these differing activities. The structure of CRLI is closely homologous to those of other Legume Lectins at the monomer level and assembles into tetramers as do many of its homologues. The CRLI carbohydrate binding site was predicted by docking with a specific inhibitory trisaccharide. CRLI possesses a hydrophobic pocket for the binding of α-aminobutyric acid and that pocket is occupied in this structure as are the binding sites for calcium and manganese cations characteristic of Legume Lectins. CRLI route-dependent effects for acute inflammation are related to its carbohydrate binding domain (due to inhibition caused by the presence of α-methyl-mannoside), and are based on comparative analysis with ConA crystal structure. This may be due to carbohydrate binding site design, which differs at Tyr12 and Glu205 position.
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structural analysis of canavalia maritima and canavalia gladiata Lectins complexed with different dimannosides new insights into the understanding of the structure biological activity relationship in Legume Lectins
Journal of Structural Biology, 2007Co-Authors: G A Bezerra, B A M Rocha, Plinio Delatorre, Taiana M Oliveira, Frederico Bruno Mendes Batista Moreno, Emmanuel P Souza, Raquel Guimaraes Benevides, Walter Filgueira De Azevedo, Benildo Sousa CavadaAbstract:Abstract Plant Lectins, especially those purified from species of the Leguminosae family, represent the best studied group of carbohydrate-binding proteins. The Legume Lectins from Diocleinae subtribe are highly similar proteins that present significant differences in the potency/efficacy of their biological activities. The structural studies of the interactions between Lectins and sugars may clarify the origin of the distinct biological activities observed in this high similar class of proteins. In this way, this work presents a crystallographic study of the ConM and CGL (agglutinins from Canavalia maritima and Canavalia gladiata , respectively) in the following complexes: ConM/CGL:Man(α1-2)Man(α1- O )Me, ConM/CGL:Man(α1-3)Man(α1- O )Me and ConM/CGL:Man(α1-4)Man(α1- O )Me, which crystallized in different conditions and space group from the native proteins. The structures were solved by molecular replacement, presenting satisfactory values for R factor and R free . Comparisons between ConM, CGL and ConA ( Canavalia ensiformis lectin) binding mode with the dimannosides in subject, presented different interactions patterns, which may account for a structural explanation of the distincts biological properties observed in the Lectins of Diocleinae subtribe.