Asn-linked oligosaccharide-dependent interaction between laminin and gp120/140. An alpha 6/beta 1 integrin

J Biol Chem. 1991 Feb 15;266(5):3349-55.

Abstract

Receptor-mediated recognition and adhesion to laminin, a specific glycoprotein from basement membranes, exert an important role in many biological phenomena. Studying cell surface proteins of B16-F10, a metastatic murine melanoma cell line, we identified a 120-140 kDa glycoprotein (gp120/140) that binds laminin. This glycoprotein was recognized by a polyclonal antibody raised against the human fibronectin receptor beta 1-integrin chain, as well as immunoprecipitated by an anti-alpha 6 chain (monoclonal antibody GoH3), characterizing it as an alpha 6/beta 1-integrin. Its binding to laminin was specific and displayed moderate affinity, as its apparent dissociation constant was 18 nM. To characterize the influence of carbohydrate moieties on the laminin-gp120/140 interaction, metaperiodate oxidation, metabolic inhibition of glycosylation, and enzymatic deglycosylation studies were performed. Our results indicate that gp120/140 Asn-linked oligosaccharides play a part in this interaction. Reciprocally, both metaperiodate and N-glycanase treatment of native laminin reduced its binding to gp120/140, characterizing the latter as a lectin-like molecule. These results point to glycosylation processes as a possible mechanism for variable binding specificity profiles among integrins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Electrophoresis, Polyacrylamide Gel
  • Female
  • Glycoproteins / metabolism
  • Integrins / metabolism*
  • Laminin / metabolism*
  • Melanoma, Experimental / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Oligosaccharides / metabolism*
  • Osmolar Concentration
  • Oxidation-Reduction
  • Tumor Cells, Cultured
  • Tunicamycin / pharmacology

Substances

  • Glycoproteins
  • Integrins
  • Laminin
  • Oligosaccharides
  • Tunicamycin