Activity of partially purified UDP-N-acetyl-alpha-D-galactosamine: polypeptide N-acetylgalactosaminyltransferase with different peptide acceptors.
As part of investigations on the role of the UDP-GalNAc-ribosome complex in the initial O-glycosylation of proteins, we have isolated from porcine gastric mucosa GalNAc-transferase, mucin and apomucin, and its three fractions containing carbohydrate in the amounts: I - 1.6%, II - 0.65% and III - 0.00% (wt/wt) of apomucin mass. Amino acid analysis showed that fractions I and II contained slightly higher amounts of serine and threonine as compared to native mucin and apomucin. The short peptide Pro-Thr-Ser-Ser-Pro-Ile-Ser-Thr was the most effectively glycosylated. Our apomucin preparations are also good acceptors of GalNAc and can be used for testing of O-glycosylation in vitro.
Porowska
H
H
Department of General and Organic Chemistry, Medical Academy, Bialystok, Poland.
Paszkiewicz-Gadek
A
A
Gindzieński
A
A
D004591:Electrophoresis, Polyacrylamide Gel; D017350:N-Acetylgalactosaminyltransferases / Q000378:metabolism*; D018000:Receptors, Peptide / Q000378:metabolism*; D013379:Substrate Specificity; D014536:Uridine Diphosphate N-Acetylgalactosamine / Q000302:isolation & purification / Q000378:metabolism*
D018000:Receptors, Peptide; D014536:Uridine Diphosphate N-Acetylgalactosamine; D017350:N-Acetylgalactosaminyltransferases