1plg
From Proteopedia
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EVIDENCE FOR THE EXTENDED HELICAL NATURE OF POLYSACCHARIDE EPITOPES. THE 2.8 ANGSTROMS RESOLUTION STRUCTURE AND THERMODYNAMICS OF LIGAND BINDING OF AN ANTIGEN BINDING FRAGMENT SPECIFIC FOR ALPHA-(2->8)-POLYSIALIC ACID
Overview
The antigen binding fragment from an IgG2a kappa murine monoclonal, antibody with specificity for alpha-(2-->8)-linked sialic acid polymers, has been prepared and crystallized in the absence of hapten. Crystals were, grown by vapor diffusion equilibrium with 16-18% polyethylene glycol 4000, solutions. The structure was solved by molecular replacement methods and, refined to a conventional R factor of 0.164 for data to 2.8 A. The binding, site is observed to display a shape and distribution of charges that is, complementary to that of the predicted conformation of the oligosaccharide, epitope. A thermodynamic description of ligand binding has been compiled, for oligosaccharides ranging in length from 9 to 41 residues, and the data, for the largest ligand has been used in a novel way to estimate the size, of the antigen binding site. A model of antigen binding is presented that, satisfies this thermodynamic data, as well as a previously reported, requirement of conformational specificity of the oligosaccharide. X-ray, crystallographic and thermodynamic evidence are consistent with a binding, site that accommodates at least eight sialic acid residues.
About this Structure
1PLG is a Protein complex structure of sequences from Mus musculus. Full crystallographic information is available from OCA.
Reference
Evidence for the extended helical nature of polysaccharide epitopes. The 2.8 A resolution structure and thermodynamics of ligand binding of an antigen binding fragment specific for alpha-(2-->8)-polysialic acid., Evans SV, Sigurskjold BW, Jennings HJ, Brisson JR, To R, Tse WC, Altman E, Frosch M, Weisgerber C, Kratzin HD, et al., Biochemistry. 1995 May 23;34(20):6737-44. PMID:7538787
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