Structures of the complexes of peanut lectin with methyl-$\beta$-galactose and N-acetyllactosamine and a comparative study of carbohydrate binding in Gal/GalNAc-specific legume lectins

Ravishankar, R and Suguna, K and Surolia, A and Vijayan, M (1999) Structures of the complexes of peanut lectin with methyl-$\beta$-galactose and N-acetyllactosamine and a comparative study of carbohydrate binding in Gal/GalNAc-specific legume lectins. In: Acta Crystallographica Section D: Biological Crystallography, 55 (8). pp. 1375-1382.

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Abstract

The crystal structures of complexes of peanut lectin with methyl-galactose and N-acetyllactosamine have been determined at 2.8 and 2.7 \AA, respectively. These, and the complexes involving lactose and the T-antigenic disaccharide reported previously, permit a detailed characterization of peanut-lectin-carbohydrate association and the role of water molecules therein. The water molecules in the combining site are substantially conserved in the four complexes. The role of interacting sugar hydroxyl groups, when absent, are often mimicked by ordered water molecules not only at the primary combining site, but also at the site of the second sugar ring. The similarity of peanut-lectin-sugar interactions with those in other galactose/N-acetylgalactosamine-specific lectins also extend to a substantial degree to water bridges. The comparative study provides a structural explanation for the exclusive specificity of peanut lectin for galactose at the monosaccharide level, compared with that of the other lectins for galactose as well as N-acetylgalactosamine. The complexes also provide a qualitative structural rationale for differences in the strengths of binding of peanut lectin to different sugars.

Item Type:	Journal Article
Publication:	Acta Crystallographica Section D: Biological Crystallography
Publisher:	International Union of Crystallography
Additional Information:	Copyright of this article belongs to International Union of Crystallography.
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	17 Oct 2007
Last Modified:	19 Sep 2010 04:40
URI:	http://eprints.iisc.ac.in/id/eprint/12144

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