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Author Appukuttan, P. S.
Source Sree Chitra Tirunal Institute for Medical Sciences & Technology
Content type Text
Publisher Journal of Molecular Recognition
File Format PDF
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Life sciences; biology ♦ Physiology & related subjects ♦ Biochemistry ♦ Technology ♦ Medicine & health
Subject Domain (in MeSH) Carbohydrates ♦ Amino Acids, Peptides, and Proteins ♦ Chemicals and Drugs ♦ Chemical Phenomena ♦ Biological Sciences
Subject Keyword Biochemistry
Abstract Preference for the beta-anomer of galactose attributed to the bovine heart 14 kDa galectin-1 (BHL-14) was re-examined using natural glycoproteins and artificially glycosylated proteins as ligands. Endogenous glycoproteins co-purified with BHL-14 during its affinity chromatographic isolation contained oligosaccharides bearing terminal alpha-linked galactose (TAG) moieties and were superior even to laminin as ligands for homogeneous BHL-14 obtained by high pressure liquid chromatography. Artificially glycosylated proteins prepared by covalent attachment of melibiose to proteins and containing TAG moieties were ligands for BHL-14, unlike their lactose counterparts which contained beta-linked galactose. Enzymatic removal of TAG moieties from the following glycoproteins abolished their recognition by BHL-14: (i) endogenous glycoproteins co-purified with BHL-14; (ii) mouse laminin; and (iii) bovine heart glycoproteins recognized by peanut agglutinin. Modification of TAG in laminin using galactose oxidase also rendered the glycoprotein inert towards BHL-14. Desialylation of human IgG, bovine thyroglobulin or laminin failed to increase the affinity of BHL-14 for these glycoproteins. Since removal of TAG or of sialic acid moiety exposed LacNAc (Gal beta1-->4 GlcNAc) in these glycoproteins, these results indicated that TAG, rather than LacNAc, is a ligand for BHL-14 on N-linked oligosaccharide chains of glycoproteins. Ready recognition of human IgA and jacalin-binding human plasma glycoproteins and non-recognition of human IgG suggested that T antigen (Galbeta1-->3 GalNAc) may also be ligand for galectin-1. Copyright (C) 2002 John Wiley Sons, Ltd.
Education Level UG and PG
Learning Resource Type Article
Educational Framework Medical Council of India (MCI)
Volume Number 15
Issue Number 4
Page Count 8
Starting Page 180
Ending Page 187