Use of Immunological Approaches to Identify a Brain Protein Kinase Isozyme

This chapter describes the use of immunological approach to identify a brain protein kinase isozyme. Type II cAMP-dependent protein kinases (PKs) from many mammalian tissues appear to be very closely related based on their physicochemical and kinetic properties, subunit compositions, and mode of activation by cAMP. For example, homogeneous preparations of the prototypic heart and skeletal muscle type II PKs are virtually identical in size, shape, ion-exchange properties, and isoelectric point. The immunological techniques of indirect immunoprecipitation and competitive binding immunoassay can be combined with functional assays to address the question of whether there are subclasses of type II PKs. Antibodies raised against bovine cerebral cortex R II have been employed as highly specific and sensitive probes for identifying and characterizing tissue-specific subclasses of type II PKs.