CHARACTERIZATION OF PROTEINS PHOSPHORYLATED BY THE CAMP-DEPENDENT PROTEIN-KINASE OF BOVINE HEART-MITOCHONDRIA

Characterization of two mitochondrial proteins of M(r) 42 and 18 kDa, respectively, phosphorylated by the cAMP-dependent protein kinase of b ovine heart mitochondria (mtPKA), is presented, A 42 kDa protein is fo und to be loosely associated to complexes I, UI and IV of the respirat ory chain and complex V (ATP synthase) in the inner mitochondrial memb rane, An 18 kDa protein is associated to complex I in the inner membra ne and in a purified preparation of this complex where it can be phosp horylated by the isolated catalytic subunit of PKA.