Formation of iron(II)-nitrosoalkane complexes: a new activity of microperoxidase 8.
Microperoxidase 8 (MP8) is a heme octapeptide, obtained by enzymatic hydrolysis of heart cytochrome c, in which a histidine is axially coordinated to the heme iron, and acts as its fifth ligand. It exhibits two kinds of activities: a peroxidase-like activity and a cytochrome P450-like activity. We here show that MP8 is not only able to oxidize various aliphatic and aromatic hydroxylamines with the formation of MP8-Fe(II)-nitrosoalkane or -arene complexes absorbing around 414 nm, but also that these complexes can be obtained by reduction of nitroalkanes. This is the first example of fully characterized iron(II)-metabolite complexes of MP8. Such complexes constitute good models for those obtained upon oxidation of amphetamine or macrolids by cytochromes P450. In addition, this is a new catalytic activity of MP8, which validates the use of this mini-enzyme as a convenient model for hemoproteins of interest in toxicology and pharmacology such as cytochromes P450 and peroxidases.
Ricoux
R
R
Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, UMR 8601 CNRS, Université Paris V, 45 rue des Saints-Pères, 75270, Paris cedex 06, France.
Boucher
J L
JL
Mansuy
D
D
Mahy
J P
JP
D000473:Alkanes / Q000737:chemistry / Q000378:metabolism*; D000588:Amines / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D002384:Catalysis; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000378:metabolism; D003574:Cytochrome c Group / Q000378:metabolism; D006418:Heme / Q000737:chemistry / Q000378:metabolism; D006736:Horses; D006898:Hydroxylamines / Q000737:chemistry; D007501:Iron / Q000737:chemistry / Q000378:metabolism*; D008024:Ligands; D008956:Models, Chemical; D009206:Myocardium / Q000737:chemistry; D009595:Nitroparaffins / Q000494:pharmacology; D010100:Oxygen / Q000378:metabolism; D010544:Peroxidases / Q000737:chemistry / Q000378:metabolism*; D011407:Propane / Q000031:analogs & derivatives* / Q000494:pharmacology; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors; D014466:Ultraviolet Rays
D000473:Alkanes; D000588:Amines; D003574:Cytochrome c Group; D006898:Hydroxylamines; D008024:Ligands; D009595:Nitroparaffins; C417255:N-isopropylhydroxylamine; D006418:Heme; D003577:Cytochrome P-450 Enzyme System; D007501:Iron; D010544:Peroxidases; C021799:microperoxidase; C016617:2-nitropropane; D010100:Oxygen; D011407:Propane