Structural and functional consequences of peptide-carbohydrate mimicry. crystal structure of a carbohydrate-mimicking peptide bound to concanavalin A

Jain, Deepti ; Kaur, Kanwaljeet ; Sundaravadivel, Balasubramanian ; Salunke, Dinakar M. (2000) Structural and functional consequences of peptide-carbohydrate mimicry. crystal structure of a carbohydrate-mimicking peptide bound to concanavalin A Journal of Biological Chemistry, 275 . pp. 16098-16102. ISSN 0021-9258

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Official URL: http://www.jbc.org/content/275/21/16098.short

Related URL: http://dx.doi.org/10.1074/jbc.275.21.16098

Abstract

The functional consequences of peptide-carbohydrate mimicry were analyzed on the basis of the crystal structure of concanavalin A (ConA) in complex with a carbohydrate-mimicking peptide, DVFYPYPYASGS. The peptide binds to the non-crystallographically related monomers of two independent dimers of ConA in two different modes, in slightly different conformations, demonstrating structural adaptability in ConA-peptide recognition. In one mode, the peptide has maximum interactions with ConA, and in the other, it shows relatively fewer contacts within this site but significant contacts with the symmetry-related subunit. Neither of the peptide binding sites overlaps with the structurally characterized mannose and trimannose binding sites on ConA. Despite this, the functional mimicry between the peptide and carbohydrate ligands was evident. The peptide-inhibited ConA induced T cell proliferation in a dose-dependent manner. The effect of the designed analogs of the peptide on ConA-induced T cell proliferation and their recognition by the antibody response against a-d-mannopyranoside indicate a role for aromatic residues in functional mimicry. Although the functional mimicry was observed between the peptide and carbohydrate moieties, the crystal structure of the ConA-peptide complex revealed that the two peptide binding sites are independent of the methyl a-d-mannopyranoside binding site.

Item Type:Article
Source:Copyright of this article belongs to The American Society for Biochemistry and Molecular Biology.
ID Code:52436
Deposited On:04 Aug 2011 07:59
Last Modified:04 Aug 2011 07:59

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