Glycosylation in vitro of an asparagine sequon catalysed by preparations of yeast cell membranes

Abstract
Preparations of yeast cell membranes can catalyze in vitro the N-acetyl-.beta.-D-glucosaminylation of the asparagine sequon at residues 34-36 of bovine pancreatic RNase A. The relevant glycopeptides were isolated from tryptic hydrolysates of the glycosylated RNase and analyzed. The donor used was UDP-N-acetyl-D-glucosamine, although the mechanism of the transfer is unknown. Mg2+ ions at concentrations of 25 mM double the activity of the enzymic transfer.