Effects of trypsin treatment on the structure and function of solubilized coupling factor-latent ATPase from Mycobacterium phlei

The effect of trypsin treatment on the solubilized coupling factorlatent ATPase from Mycobacterium phlei was studied. Maximal stimulation of ATPase activity by trypsin is accompanied by a decrease of about 20,000 daltons in molecular weight and a complete loss of the ability to rebind to depleted membranes. There is also conversion of the A subunit of the latent enzyme to an A″ form via an A′ intermediate. The increase in ATPase activity, loss of coupling factor activity, and loss of rebinding capacity changed in a different manner in response to partial degrees of trypsin activation, indicating that each of these functions may have a different structural requirement.