Two types of rat gastric mucus glycoprotein subunits.
Gastric mucus glycoproteins were extracted with 2% Triton X-100 from rat gastric corpus and antrum and purified by CsCl equilibrium centrifugation. Corpus mucus glycoproteins were degraded into what appeared to be two "subunits" (Mw 4.4 x 10(5) and 6 x 10(6)) by the reduction of disulfide bonds. Papain digestion of the latter produced glycopeptides with a molecular weight of approximately 4.4 x 10(5). This type of subunit had carbohydrate chains with about 9 sugars attached to every 2 amino acid residues. Papain digestion of the former type of subunit revealed no change in the elution profile on Bio-Gel A-15m. This type of subunit had carbohydrate chains with 17-19 sugars attached to every 3 amino acid residues. The subunit of antral mucus glycoproteins was essentially the same as the former type of corpus subunits in molecular weight (Mw 4.4 x 10(5)) and average oligosaccharide chain length. These results suggest that there are two distinct types of mucus glycoprotein subunits in rat stomach.
Ohara
S
S
Department of Biochemistry, School of Medicine, Kitasato University, Kanagawa.
Ishihara
K
K
Hotta
K
K
D000818:Animals; D002241:Carbohydrates / Q000302:isolation & purification; D006023:Glycoproteins / Q000145:classification / Q000302:isolation & purification*; D008297:Male; D009093:Mucus / Q000032:analysis*; D011487:Protein Conformation; D011706:Pyloric Antrum / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D013270:Stomach / Q000032:analysis*
D002241:Carbohydrates; D006023:Glycoproteins