title: Site-directed mutageneses of rat liver cytochrome P-450d: axial ligand and heme incorporation.
abstract: By oligonucleotide-directed mutageneses, 13 substitutions of amino acids at the carboxy-terminal region of rat liver cytochrome P-450d were done as follows: (A) Phe-449----Tyr; (B) Gly-450----Ser; (C) Leu-451----Ser; (D) Gly-452----Glu; (E) Lys-453----Glu; (F) Arg-454----Leu; (G) Arg-455----Gly; (H) Cys-456----Tyr; (I) Cys-456----His; (J) Ile-457----Ser; (K) Gly-458----Glu; (L) Glu-459----Ala; (M) Ile-460----Ser. The CO-bound reduced forms of the wild type and mutants B-G, J, L, and M gave Soret peaks at 448 nm. The CO complex of mutant A gave a Soret peak at 445 nm. The intensities of the CO-bound forms of mutants A, C, D, and J were very small compared with that of the wild-type complex. The CO-reduced forms of mutants H, I, and K did not give a Soret peak around 450 nm at all. The 448-nm peak of mutant F was unstable and quickly disappeared with the concomitant appearance of a peak at 420 nm.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001665:Binding Sites; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis / Q000235:genetics*; D005822:Genetic Vectors; D006418:Heme / Q000378:metabolism*; D008024:Ligands; D008099:Liver / Q000201:enzymology*; D009154:Mutation; D009841:Oligonucleotides / Q000494:pharmacology; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000235:genetics
chemical_list: D000596:Amino Acids; D008024:Ligands; D009841:Oligonucleotides; D006418:Heme; D003577:Cytochrome P-450 Enzyme System