INFLUENCE OF THE INHIBTOR ON ADENOSINE TRIPHOSPHA1TF- DEPENDENT REACrIONS

1. The activity of the ATPase (adenosine triphosphatase) of phosphorylating particles prepared by sonication of bovine heart mitochondria in the presence of MgCl2 and ATP is influenced by the isolation method for the mitochondria used In the prepaaltion of particles. Type-I particles, made from mitochondria isolated in a medium lacking succinate, have a lower ATPase activity than do Type-fl particles, which are prepared from mitochondria isolated in a medium containiag succinate. 2. CenttifugationftUndet appropriate energized conditions increases tbe ATPase activity of Type-I particles almost to that of the Type-II particles. The ATPase activity ofTypetI particles was only slightly stimulated by this procedure. These data are interpreted s indicating a highe i content of the ATPase-inhibitor protein in the Type-I particles. 3. A comparison was made ofthe ATP-driven enhancement of 8-anilinonaphthalene-1-sulphonate fluoretence