Immunochemical studies on human, bovine and pig brain regulatory subunits of cAMP-dependent protein kinase type II.

Regulatory subunits type II (RII) purified from human, pig and bovine brains were compared using II monoclonal antibodies (MoAb) against bovine brain RII. Bovine RII has at least 5 antigenic sites located in the N-terminal 1-110 residues. Immunochemical difference detected between human and animal RII was more pronounced than between pig and bovine RII. Certain MoAb influenced R-cAMP binding and holoenzyme formation. RII of the three species responded to MoAb attachment in a similar fashion. The results suggest that anchoring of neural protein kinase via the N-terminal part of RII may influence the enzyme activity.