Chemical and physical properties of the human urinary glycoprotein with gastric antisecretory activity

Abstract

The chemical and physical properties of the high-molecular-weight glycoprotein (SO20, w = 8S; Ve=Vo on Sephadex G-200) with gastric antisecretory activity extracted from the urine of pregnant women were studied. Gel filtration in the presence of sodium dodecyl sulphate and sodium dodecyl sulphate/polyacrylamide-disc-gel electrophoresis indicated subunit mol.wts. of 16 000 +/- 1500 and 13 000 +/- 1000 respectively. Reaggregation of the subunits and partial recovery of the biological activity were observed on removal of the detergent. The partial C-terminal sequence was found to be Phe-Tyr-Leu-Val-OH, whereas glycine appears to be the N-terminal amino acid. The carbohydrate composition was examined; all galactosamine was found to be O-glycosidically linked to the polypeptide chain.

Purification of the human urinary glycoprotein with gastric antisecretory activity by ‘subunit exchange chromatography’

“…This inhibitor is made of identical subunits whose molecular weight was evaluated to be -15 000 by gel-filtration and disc-gel electrophoresis in the presence of sodium dodecyl sulphate (SDS) and by C-terminal analysis [3]. Preliminary experiments have suggested that the molecular weight of the glycoprotein depends on pH due to a reversible associationdissociation process.…”