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Publication Abstract from PubMed

Carbohydrate-protein interactions play a key role in many biological processes. Cramoll is a lectin purified from Cratylia mollis seeds that is taxonomically related to concanavalin A (Con A). Although Cramoll and Con A have the same monosaccharide specificity, they have different glycoprotein binding profiles. We report the primary structure of Cramoll, determined by Edman degradation and mass spectrometry and its 1.77 A crystallographic structure and compare it with the three-dimensional structure of Con A in an attempt to understand how differential binding can be achieved by similar or nearly identical structures. We report here that Cramoll consists of 236 residues, with 82% identity with Con A, and that its topological architecture is essentially identical to Con A, because the Calpha positional differences are below 3.5 A. Cramoll and Con A have identical binding sites for MealphaMan, Mn2+, and Ca2+. However, we observed six substitutions in a groove adjacent to the extended binding site and two in the extended binding site that may explain the differences in binding of oligosaccharides and glycoproteins between Cramoll and Con A.

Amino acid sequence and tertiary structure of Cratylia mollis seed lectin.,De Souza GA, Oliveira PS, Trapani S, Santos AC, Rosa JC, Laure HJ, Faca VM, Correia MT, Tavares GA, Oliva G, Coelho LC, Greene LJ Glycobiology. 2003 Dec;13(12):961-72. Epub 2003 Sep 9. PMID:12966038^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.