Atp Synthetase - Mixture Of Factor-A And Avidin Sensitive Atp-Pi Exchange Activity

The ATP-P i exchange activity of highly purified preparations of ‘ATP synthetase’ was inhibited by F 1 -antiserum, Pullman inhibitor, azide and also by avidin (See You and Hatefi, 1973) . The inhibition produced by the first three was relieved in the presence of ADP, and the avidin sensitivity was lost on pretreatment on the avidin with biotin. It is concluded that the ATP-P i exchange resulted from the combined action of Factor A and a contaminating avidin-sensitive enzyme. The ADP necessary for the exchange reaction catalyzed by the latter was generated by the ATPase activity of Factor A.