Purification and characterization of cytochrome P-450 isozymes from phenobarbital-induced adult hen liver.

1. Two cytochrome P-450 isozymes (P-450 PB-A, PB-B) and cytochrome b5 were purified from livers of phenobarbital-treated adult hens. 2. Both the enzymes exhibited the same apparent molecular weight (54,000). 3. They could be distinguished on the basis of immunochemical properties, spectral properties, peptide pattern after partial proteolysis, tryptic peptide pattern, and N-terminal sequence. 4. The antibodies raised against P-450 PB-A and PB-B did not cross-react with microsomal P-450s of rat, mice, cat, or catfish species by immunoblotting.