Blood group-active carbohydrate chains on the receptor for epidermal growth factor of A431 cells

EMBO J. 1984 Oct;3(10):2227-33.

Abstract

The antigens expressed on the carbohydrate chains of the receptor for epidermal growth factor of A431 cells were studied by immunoblotting with monoclonal antibodies. Blood group A and the Type 1 based blood group ALeb and Lea antigens were detected as well as antigens associated with unsubstituted, monofucosylated and difucosylated Type 2 blood group chains. The Lea and the difucosylated Type 2 antigen activities were abolished by treating the blotted receptor with endo-beta-galactosidase, indicating that they are expressed on backbone structures of poly-lacto/neolacto type. (The term 'poly-lacto/neolacto' is used here to describe oligosaccharide backbone structures consisting of repeating Type 1, Gal beta 1-3GlcNAc (lacto) or Type 2, Gal beta 1-4GlcNAc (neolacto) sequences.) The glycosidic linkage of oligosaccharides to protein was investigated using Pronase digests of the receptor biosynthetically labelled with [3H]glucosamine or [3H]fucose. The oligosaccharides were alkali-resistant, consistent with N- rather than O-glycosidically linked chains. A proportion of [3H]fucose-labelled glycopeptides was susceptible to endo-beta-galactosidase, confirming the immunoblotting experiment using antibodies against the Lea and the difucosylated Type 2 antigenic determinants. Oligosaccharides were released from the [3H]fucose- and [3H]-glucosamine-labelled glycopeptides by hydrazinolysis. Chromatography of the oligosaccharides on Bio-Gel P6 and Concanavalin A columns indicated a spectrum of oligosaccharides which include those of high mannose type labelled with [3H]glucosamine, and a mixture of oligosaccharides labelled with [3H]fucose and [3H]glucosamine of bi- and multiantennary complex types of which a subpopulation is susceptible to digestion with endo-beta-galactosidase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ABO Blood-Group System / immunology*
  • Animals
  • Carbohydrate Sequence
  • Carcinoma, Squamous Cell / analysis*
  • Cell Line
  • ErbB Receptors
  • Fucose / metabolism
  • Glucosamine / metabolism
  • Humans
  • Mice
  • Molecular Weight
  • Neuraminidase / metabolism
  • Oligosaccharides / immunology*
  • Receptors, Cell Surface / analysis*

Substances

  • ABO Blood-Group System
  • Oligosaccharides
  • Receptors, Cell Surface
  • Fucose
  • ErbB Receptors
  • Neuraminidase
  • Glucosamine