Purification and characterization of a dicyclohexylcarbodiimide-sensitive adenosine triphosphatase complex from membranes of Escherichia coli.

The energy transducing adenosine 5′-triphosphatase (ATPase) complex was extracted with deoxycholate from $\text{Escherichia coli}$ membranes and purified 20–25 fold. The detergent-solubilized ATPase complex was inhibited more than 80% by dicyclohexylcarbodiimide (DCCD). Its sedimentation velocity coefficient was 14.7s in the presence of deoxycholate. Phospholipid stimulated its hydrolytic activity and maximized DCCD sensitivity. These parameters clearly differentiate the ATPase complex from the DCCD-insensitive, soluble ATPase prepared by extraction with EDTA at low ionic strength. The purified ATPase complex showed twelve discrete bands on lauryl sulfate gel electrophoresis. Five of these components co-electrophresed with subunits of soluble ATPase. Of the seven additional components, primarily two were precipitated with antibody to soluble ATPase. The protein which specifically reacts with DCCD co-migrated with one of these subunits.