Microheterogeneity of cytochrome P450(LM2) as revealed by isoelectric focusing.

The homogeneity of different preparations of cytochrome P450(LM2), the major form of cytochrome P450 found in the liver microsomes of phenobarbital-treated rabbits, was checked by SDS polyacrylamide gel electrophoresis and N-terminal amino acid sequencing. In SDS-PAGE all the preparations migrated as a single protein band of molecular mass 49 kDa. The electrophoretic mobility of this band corresponded to that of the major phenobarbital-inducible band in the microsomes of phenobarbital-treated rabbits.