Microsomal cytochromes P-450 from marine crabs

Cytochromes P-450 were isolated from the hepatopancreas of several species of crabs (Libinia emarginata, Callinectes sapidus, Menippe mercenaria and Uca minax). Elution profiles from an ion exchange column showed similar profiles for all species, indicating one broad cytochrome P-450 peak eluting at 0.2 M K Cl. Hydroxyapatite chromatography resolved the P-450 into three forms (cytochromes P-450I, P-450II and P-450III). The forms of cytochrome P-450 in the different crabs were compared with respect to their spectra and molecular weights. Cytochromes P-450I and P-450III from Callinectes, Menippe and Uca had slightly different spectral properties. The Soret peaks of the oxidized spectra had wavelength maxima of 414-416 nm, while the reduced spectra was 417-424 nm. The Soret peak of Libinia P-450II was 417 nm and 415 nm, for the oxidized and reduced forms, respectively. Molecular weights for cytochromes P-450I and P-450III ranged from 51,000 to 53,000. Libinia P-450II had a molecular weight of 49,000.