Binding of N-dansylgalactosamine to winged-bean tuber lectin: studies by fluorescence quenching titrations

She, Manjunath S and Madaiah, M and Khan, MI (1988) Binding of N-dansylgalactosamine to winged-bean tuber lectin: studies by fluorescence quenching titrations. In: Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 954 . pp. 44-49.

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Abstract

The winged-bean tuber lectin binds to N-dansyl(5-dimethylaminonaphthalene-1-sulphonic acid)galactosamine, leading to a 12.5-fold increase in dansyl fluorescence with a concomitant 25 nm blue-shift in the emission maximum. The enhancement of fluorescence intensity was completely reversed by the addition of methyl α-galactopyranoside. The lectin has two binding sites per molecule for this fluorescent sugar and an association constant of 2.59 · 105 M−1 at 25° C. The binding of N-dansylgalactosamine to the lectin shows that it can accommodate a large hydrophobic substituent on the C-2 carbon of d-galactose. Studies with other sugars indicate that a hydrophobic substituent with α-conformation at the anomeric position increases the affinity of binding. The C-4 and C-6 hydroxyl groups are also critical for sugar binding to this lectin.

Item Type:	Journal Article
Publication:	Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology
Publisher:	Elsevier Science
Additional Information:	Copy rights of this article belongs to Elsevier Science.
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	04 Aug 2009 02:38
Last Modified:	19 Sep 2010 05:40
URI:	http://eprints.iisc.ac.in/id/eprint/22023

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