Intrinsic Fluorescence Studies on Saccharide Binding to Artocarpus Integrifolia Lectin

Sastry, Krishna MV and Surolia, A (1986) Intrinsic Fluorescence Studies on Saccharide Binding to Artocarpus Integrifolia Lectin. In: Bioscience Reports, 6 (10). pp. 853-860.

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Abstract

The combining region of Artocarpus integrifolia lectin has been studied by using the ligand-induced changes in the fluorescence of the lectin. The saccharide binding properties of the lectin show that C-1, C-2, C-4, and C-6 hydroxyl groups of D-galactose are important loci for sugar binding. The $\alpha$-anomer of galactose binds more strongly than its $\beta$-counterpart. Inversion in the configuration at C-4 as in glucose results in a loss of binding to the lectin. The C-6 hydroxyl group is also presumably involved in binding as D-fucose does not bind to the lectin. The lectin binds to the Thomsen-Friedenreich antigen (Gal$\beta$(1$\rightarrow$3)GalNAc) more strongly than the other disaccharides studied, viz. Gal$\beta$ (1$\rightarrow$4) Gal and Gal$\beta$ (1$\rightarrow$3) GlcNA, which are topographically similar to T-antigen. This observation suggests that the combining region of Artocarpus lectin is complementary to that of T-antigen. Solvent accessibility of the protein fluorophores have been probed by the quenching of protein fluoroscence by iodide ion in the absence and presence of sugar. In the presence of sugar a slight inaccessibility of the fluorophores to the solvent has been observed.

Item Type: Journal Article Copyright to this article belongs to Springer Netherlands. fluorescence;lectin;saccharide;sugar. Division of Biological Sciences > Molecular Biophysics Unit 26 Jun 2008 19 Sep 2010 04:46 http://eprints.iisc.ernet.in/id/eprint/14690