Glycosylation of ribonuclease A catalysed by rabbit liver extracts

Biochem J. 1975 Feb;146(2):299-307. doi: 10.1042/bj1460299.

Abstract

Crude extracts of rabbit liver catalyse in vitro the transfer of N-acetylglucosamine from UDP-N-acetylglucosamine to bovine pancreatic ribonuclease A. The enzymic activity is contained in rough endoplasmic reticulum. It has an absolute requirement for a bivalent metal ion: Co-2+ greater than Mn-2+ greater than Ni-2+. Mg-2+ is ineffective. There is enzymic activity in the absence of detergent, but increased activity is observed in the presence of Triton X-100. The site of glycosylation of ribonuclease A is asparagine-34, and glycosylation occurs only at this point. These findings agree with the hypothesis that the sequence Asn-X-Thr(Ser) (where X may be one of a number of types of amino acid) is a necessary, but not sufficient, condition for N-acetylglucosaminylation of a protein-bound asparagine residue.

MeSH terms

  • Acetylglucosamine / metabolism*
  • Animals
  • Asparagine
  • Cobalt
  • Endoplasmic Reticulum / enzymology
  • Glucosamine / analogs & derivatives*
  • Glycopeptides / isolation & purification
  • Liver / enzymology*
  • Manganese
  • Nickel
  • Peptides / analysis
  • Polyethylene Glycols
  • Rabbits
  • Ribonucleases / analysis
  • Ribonucleases / metabolism*

Substances

  • Glycopeptides
  • Peptides
  • Cobalt
  • Polyethylene Glycols
  • Manganese
  • Asparagine
  • Nickel
  • Ribonucleases
  • Glucosamine
  • Acetylglucosamine