Comparison of the peptide map and functional properties of monooxygenases induced by 3-methylcholanthrene and β-naphthoflavone

The similarity of the catalytic, spectral, electrophoretic, and immunochemical properties of microsomal cytochromes P-448 (molecular weight 56,000), synthesized de novo after administration of 3-methylcholanthrene and β-naphthoflavone to rats, was demonstrated. The identity of the peptide maps of the microsomal and isolated cytochrome P-448 is evidence of adequacy of the method of limited proteolysis for establishing the homogeneity and comparing the structure of the microsomal hemoproteins. The data obtained substantiate the approach for the study of the similarity and differences in the structure and enzymatic activity of various forms of monooxygenases without their preliminary isolation from the microsomal membrane