Isolation, purification and characterization of the ATPase complex from the thermophilic cyanobacterium Synechococcus 6716

Abstract

The ATPase complex is isolated and purified from membrane vesicles of the thermophilic cyanobacterium Synechococcus 6716 by octyl glucoside and cholic acid by a modification of the procedure for its extraction from spinach chloroplasts. The complex is purified by differential centrifugation and ammonium sulfate precipitation and by gel filtration on Sepharose 6B. The purified fraction, without any phycocyanin contamination, shows ATP hydrolysis activity and Pi/ATP exchange activity of 1564 and 350 nmol .cntdot. min-1 .cntdot. mg protein-1, respectively. N,N''-Dicyclohexylcarbodiimide inhibits the ATP hydrolysis activity of this purified fraction. On polyacrylamide gels most typical F1 ATPase polypeptides are identified, but the low MW polypeptides visible cannot be ascribed to the F0 part of the complex with certainty; nonidentified bands around 30 kDa [kilodaltons] are also present.