The participation of ribosome-UDP-GalNAc complex in the initiation of protein glycosylation in vitro

The gastric epithelial cells ribosome-UDP-GalNAc complex is a donor of UDP- GalNAc as the substrate for N-acetylgalactosaminyltransferase, which catalyse the transfer of GalNAc residue to the polypeptide, existing on polysomes. It was observed that the deglycosylated porcine mucin and synthetic peptide (PTSSPIST) can be also glycosylated with participation of N-acetylgalactosaminyltransferase and ribosome- UDP-GalNAc complex. The probability of the ribosome-UDP-GalNAc complex as an intermediate in the O-glycosylation is considered.