Proton-translocating adenosine triphosphatase of chromaffin-granule membranes. The active site is in the largest (70 kDa) subunit.
The proton-translocating adenosine triphosphatase (ATPase) of bovine chromaffin granules contains up to five different polypeptides. Its activity is inhibited by N-ethylmaleimide, and ATP protects the enzyme from inhibition. After treatment of membranes with N-[2-3H]ethylmaleimide, only one polypeptide is strongly radiolabelled: this is the largest (70 kDa) subunit of the proton-translocating ATPase. This subunit therefore contains the ATP-hydrolysing site. Two-dimensional electrophoresis reveals heterogeneity in this polypeptide.
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002837:Chromaffin Granules / Q000201:enzymology*; D002838:Chromaffin System / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D005033:Ethylmaleimide / Q000494:pharmacology; D007425:Intracellular Membranes / Q000201:enzymology; D006180:Proton-Translocating ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism*
D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases; D005033:Ethylmaleimide