Molecular heterogeneity of rabbit heart phosphorylase kinase

Isolation of cDNA clones for the catalytic gamma subunit of mouse muscle phosphorylase kinase: expression of mRNA in normal and mutant Phk mice.

“…Skeletal muscle contains the highest amounts of Phk enzymatic activity, although activity is also observed in liver, cardiac muscle, brain, and several other tissues (4). Kinetic differences exist between the cardiac and adult skeletal muscle enzymes, and the liver and skeletal muscle enzymes are known to be separate isozymes (5)(6)(7). Cardiac muscle and red skeletal muscle Phk contain an isoform of the a subunit, termed a', distinct from that found in white skeletal muscle (8).…”