Characterization of Syrian hamster gastric mucosal H+,K+-ATPase.
Employing a simple one-step sucrose gradient fractionation method, gastric mucosal membrane of Syrian hamster was prepared and demonstrated to be specifically enriched in H+,K+-ATPase activity. The preparation is practically devoid of other ATP hydrolyzing activity and contains high K+-stimulated ATPase activity of at least 4-5 fold compared to basal ATPase activity. The H+,K+-ATPase showed hydroxylamine-sensitive phosphorylation and K+-dependent dephosphorylation of the phosphoenzyme, characteristic inhibition by vanadate, omeprazole and SCH 28080, and nigericin-reversible K+-dependent H+-transport--properties characteristic of gastric proton pump. One notable difference with H+,K+-ATPase of other species has been the observation of valinomycin-independent H+ transport in such membrane vesicles. It is proposed that such H+,K+-ATPase-rich hamster gastric mucosal membrane preparation might provide a unique model to study physiological aspects of H+,K+-ATPase function in relation to HCl secretion.
Chatterjee
P K
PK
Indian Institute of Chemical Biology, Calcutta, India.
Das
P K
PK
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D000897:Anti-Ulcer Agents / Q000494:pharmacology; D006224:Cricetinae; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005744:Gastric Acid / Q000378:metabolism; D005753:Gastric Mucosa / Q000201:enzymology* / Q000378:metabolism; D017506:H(+)-K(+)-Exchanging ATPase / Q000302:isolation & purification* / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology; D008297:Male; D008647:Mesocricetus / Q000378:metabolism*; D009550:Nigericin / Q000494:pharmacology; D009853:Omeprazole / Q000494:pharmacology; D010766:Phosphorylation; D054328:Proton Pump Inhibitors; D011522:Protons; D013379:Substrate Specificity; D014638:Vanadates / Q000494:pharmacology
D000897:Anti-Ulcer Agents; D004791:Enzyme Inhibitors; D007093:Imidazoles; D054328:Proton Pump Inhibitors; D011522:Protons; C035235:Sch 28080; D014638:Vanadates; D000255:Adenosine Triphosphate; D017506:H(+)-K(+)-Exchanging ATPase; D009853:Omeprazole; D009550:Nigericin