Resonance Raman study on mutant cytochrome P-450 obtained by site-directed mutagenesis.
Resonance Raman spectra were observed for the threonine-301 to serine or valine mutant as well as the wild type of rabbit liver microsomal cytochrome P-450 [laurate(omega-1)-hydroxylase] (P-450(omega-1], which were prepared through site-directed mutagenesis. The high-spin marker resonance Raman (RR) bands became similarly stronger for all the P-450s examined in the oxidized form upon addition of laurate, and the RR spectra in the higher frequency region of the oxidized, reduced and CO-adduct forms did not distinctly differ among the P-450s examined. Nevertheless, the Fe-CO stretching mode (vFe-CO) of the CO adduct exhibited an upshift for the valine mutant, suggesting positional proximity of Thr-301 to bound CO like Thr-252 of P-450cam, in agreement with the expectation from the sequence analysis. The vFe-CO band was shifted to higher frequency upon binding of normal alkyl fatty acids with C10 or longer alkyl chain but little affected by binding of shorter fatty acids.
Egawa
T
T
Institute for Molecular Science, Okazaki National Research Institutes, Myodaiji, Okazaki, Japan.
Imai
Y
Y
Ogura
T
T
Kitagawa
T
T
D000818:Animals; D042926:Cytochrome P-450 CYP4A; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D008862:Microsomes, Liver / Q000201:enzymology*; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010084:Oxidation-Reduction; D011487:Protein Conformation; D011817:Rabbits; D012441:Saccharomyces cerevisiae / Q000235:genetics; D012694:Serine; D013059:Spectrum Analysis, Raman / Q000379:methods; D013912:Threonine; D014633:Valine
D013912:Threonine; D012694:Serine; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D042926:Cytochrome P-450 CYP4A; D014633:Valine