Venkoba R Srinivas

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Differential scanning calorimetry of solutions of WBAII and in presence of sugar ligands shows that WBAII dimer dissociates to its constituent monomeric subunits at the denaturation temperature. The thermal denaturation of WBAII consists of the unfolding of two independent domains of WBAII similar to that of basic winged bean lectin and ECorL and in(More)
We report cloning of the DNA encoding winged bean basic agglutinin (WBA I). Using oligonucleotide primers corresponding to N- and C-termini of the mature lectin, the complete coding sequence for WBA I could be amplified from genomic DNA. DNA sequence determination by the chain termination method revealed the absence of any intervening sequences in the gene.(More)
Thermodynamic parameters associated with the unfolding of the legume lectin, WBA II, were determined by isothermal denaturation. The analysis of isothermal denaturation data provided values for conformational stability and heat capacity for WBA II unfolding. To explore the role of intersubunit contact in stability, we carried out similar studies under(More)
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(More)
Structures of two crystal forms of the dimeric acidic winged bean agglutinin (WBAII) complexed with methyl-alpha-D-galactose have been determined at 3.0 A and 3.3 A resolution. The subunit structure and dimerisation of the lectin are similar to those of the basic lectin from winged bean (WBAI) and the lectin from Erythrina corallodendron (EcorL). The(More)
A central question in biological chemistry is the minimal structural requirement of a protein that would determine its specificity and activity, the underlying basis being the importance of the entire structural element of a protein with regards to its activity vis à vis the overall integrity and stability of the protein. Although there are many reports on(More)
The crystal structure of the saccharide-free form of the basic form of winged-bean agglutinin (WBAI) has been solved by the molecular-replacement method and refined at 2.3 A resolution. The final R factor is 19.7% for all data in the resolution range 8.0-2.3 A. The asymmetric unit contains two half-dimers, each located on a crystallographic twofold axis.(More)
The acidic lectin (WBAII) from the winged bean (Psophocarpus tetragonolobus) binds to the H-antigenic determinant on human erythrocytes and to the T-antigenic disaccharide Gal-beta1,3-GalNAc. Two crystal forms of WBAII were obtained in the presence of methyl-alpha-D-galactose. Form I belongs to space group R3 with unit-cell dimensions a = b = 182.11, c =(More)
The conformational stability of the homodimeric pea lectin was determined by both isothermal urea-induced and thermal denaturation in the absence and presence of urea. The denaturation profiles were analyzed to obtain the thermodynamic parameters associated with the unfolding of the protein. The data not only conform to the simple A2 if 2U model of(More)
The ability to discriminate between galactose and N- acetylgalactosamine, 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(More)