Catfish (Clarias batrachus) serum lectin recognizes polyvalent Tn [alpha-D-GalpNAc1-Ser/Thr], Talpha [beta-D-Galp-(1-->3)-alpha-D-GalpNAc1-Ser/Thr], and II [beta-D-Galp(1-->4)-beta-D-GlcpNAc1-] mammalian glycotopes

Carbohydr Res. 2008 Sep 22;343(14):2384-92. doi: 10.1016/j.carres.2008.06.030. Epub 2008 Jul 8.

Abstract

A new calcium dependent GalNAc/Gal specific lectin was isolated from the serum of Indian catfish, Clarias batrachus and designated as C. batrachus lectin (CBL). It is a disulfide-linked homodecameric lectin of 74.65kDa subunits and the oligomeric form is essential for its activity. Binding specificity of CBL was investigated by enzyme-linked lectin-sorbent assay using a series of simple sugars, polysaccharides, and glycoproteins. GalNAc was more potent inhibitor than Gal; and alpha glycosides of both were more inhibitory than their beta counterparts. CBL showed maximum affinity for human tumor-associated Tn-antigens (GalNAcalpha1-Ser/Thr) at the molecular level and was 3.5 times higher than GalNAc. CBL interacted strongly with polyvalent Tn and Talpha (Galbeta1,3GalNAcalpha1-) as well as multivalent-II (Galbeta1,4GlcNAcbeta1-) antigens containing glycoproteins and intensity of inhibition was 10(3)-10(5) times more than monovalent ones. The overall specificity of CBL lies in the order of polyvalent Tn, Talpha and II>>>>monovalent Tn > or = Me-alphaGalNAc>monovalent Talpha> Me-betaGalNAc>Me-alphaGal>monovalent T>GalNAc>monovalent F>monovalent II>Me-betaGal>Gal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Tumor-Associated, Carbohydrate / chemistry*
  • Antigens, Tumor-Associated, Carbohydrate / metabolism*
  • Catfishes* / blood
  • Glycoproteins / metabolism
  • Hemagglutination
  • Humans
  • Lectins / blood
  • Lectins / chemistry
  • Lectins / isolation & purification
  • Lectins / metabolism*
  • Mammals
  • Molecular Weight
  • Protein Binding
  • Spectrometry, Mass, Electrospray Ionization
  • Substrate Specificity

Substances

  • Antigens, Tumor-Associated, Carbohydrate
  • Glycoproteins
  • Lectins
  • Tn antigen