Browsing by Author "JAISON, PL"

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    EPITOPES RECOGNIZED BY SERUM ANTI-ALPHA-GALACTOSIDE ANTIBODY ARE PRESENT ON BRAIN GLYCOPROTEINS IN MAN
    (JOURNAL OF BIOSCIENCES, 1993) JAISON, PL; KANNAN, VM; GEETHA, M; APPUKUTTAN, PS
    Naturally occurring serum IgG against terminal alpha-galactoside epitopes (anti-Gal), present exclusively in man, apes and old world monkeys, was used as probe for these epitopes in human brain. Human brain grey matter soluble glycoproteins enriched in alpha-galactosyl groups by affinity chromatography on jacalin-sepharose, specifically binds to human anti-Gal in immuno dot blots. Anti-Gal recognized exclusively the terminal alpha-galactoside epitope in human brain glycoproteins since binding was abolished by the presence of 1-0-methyl alpha-D-galactopyranoside as well as by pretreatment of glycoproteins with coffee bean alpha-galactosidase. Anti-Gal-peroxidase staining of jacalin-binding human brain glycoproteins in western immuno blots revealed mainly five anti-Gal-binding polypeptides with M(r) (in kDa) of 94, 108, 180, 210 and 230 respectively. Since the presence of anti-Gal in higher animals accompanies suppression of the corresponding epitope in most tissues, apparently to maintain immunological balance, possible implications of the above observation for autoimmunity, tumor metastasis and infection are discussed.
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    IDENTIFICATION OF ENDOGENOUS SOLUBLE GLYCOPROTEIN RECEPTORS OF BOVINE BRAIN GRAY-MATTER 14 KDA BETA-GALACTOSIDE-BINDING LECTIN
    (INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS, 1994)
    The 14 kDa beta-galactoside-binding lectin from bovine brain grey matter (BBL) covalently attached to caproic acid-Sepharose by the N-hydroxy succinimide procedure was used to isolate endogenous glycoprotein receptors of this lectin. BBL-Sepharose could sugar-specifically retain several endogenous soluble glycoproteins with subunit molecular mass(in kDA) 44, 51, 60, 123 and 186. BBL, conjugated with horse radish peroxidase, could sugar-specifically recognize several glycoprotein subunits with molecular mass (in kDA) 58, 87, 117 and 186 on Western blots. The only protein from an extract of bovine brain grey matter, that retained on Sepharose-immobilized endogenous N-linked glycoproteins and subsequently eluted with beta-galactosides was BBL as confirmed by electrophoresis and agglutination inhibition measurement. N-linked glycoproteins from-bovine heart and even from human placenta were also efficient receptors of BBL. These results suggest that 14 kDa beta-galactoside-binding lectin is the major protein, if not the only one, that sugar-specifically interacts with endogenous soluble glycoproteins in bovine brain grey matter.
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    RAPID ISOLATION OF HUMAN PLASMA ANTI-ALPHA-GALACTOSIDE ANTIBODY USING SUGAR-SPECIFIC BINDING TO GUAR GALACTOMANNAN OR AGAROSE
    (INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS, 1992)
    A method of purifying the naturally occurring antibody to alpha-galactoside moiety (anti-alpha-Gal) in human plasma by a single-step affinity chromatography on cross-linked guar galactomannan (CLGG) or agarose (Sepharose 4B) is described. IgG nature of the two preparations, as revealed by agar gel diffusion, as well as their preference for alpha-anomer of galactose, as revealed in inhibition of their agglutination of trypsinized rabbit erythrocytes by sugars, identified them with anti-alpha-Gal. The antibody binding capacity of Sepharose 4B was only a third of that of CLGG. Both gels showed similar dependence on ionic strength for binding. The pH optimum for binding of anti-alpha-Gal to CLGG was 8.0. Significantly anti-alpha-Gal binding to Sepharose was unaffected by CNBr activation and ligand coupling to the gel, thus warning that contaminating plasma could introduce artifacts in agarose-based chromatography of human tissue biomolecules.