Activation and inhibition of the Escherichia coli F1-ATPase by monoclonal antibodies which recognize the ϵ subunit

The properties of two monoclonal antibodies which recognize the epsilon subunit of Escherichia coli F1-ATPase were studied in detail. The epsilon subunit is a tightly bound but dissociable inhibitor of the ATPase activity of soluble F1-ATPase. Antibody epsilon-1 binds free epsilon with a dissociation constant of 2.4 nM but cannot bind epsilon when it is associated with F1-ATPase. Likewise epsilon cannot associate with F1-ATPase in the presence …