[Inactivation of sodium dithionite reduced cytochromes P-450 of different origins].
The inactivation of five dithionite reduced soluble cytochrome P-450 isoforms has been studied. The inactivation of microsomal rabbit liver isoform LM2 and bacterial linalool cytochrome P-450 is followed by its conversion into cytochrome P-420. Microsomal rabbit liver isoform LM4, bacterial camphor and p-cymene cytochromes P-450 were not inactivated under these conditions. The inactivation of linalool cytochrome P-450 and LM2 isoform is a first order reaction; the rate constants for linalool cytochrome P-450 and LM2 are 0.3 and 0.1 min-1, respectively. In the case of linalool cytochrome P-450 its carboxycomplex (Fe2+-CO) is inactivated, while in the case of LM2 the inactivation affects its oxycomplex (Fe2+-O2). The amino acid residues of linalool cytochrome P-450 are probably modified due to a direct electron transfer in its carboxycomplex. The amino acid residues of LM2 isoform are modified, presumably due to oxidation by oxygen active species which are released during the oxycomplex decay.
I M
IM
Mokhosoev
G P
GP
Kuznetsova
M A
MA
Al'terman
G I
GI
Bachmanova
A I
AI
Archakov
D000818:Animals; D065607:Cytochrome P-450 Enzyme Inhibitors; D005609:Free Radicals; D006207:Half-Life; D066298:In Vitro Techniques; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D007700:Kinetics; D008862:Microsomes, Liver / Q000201:enzymology; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D011817:Rabbits; D013379:Substrate Specificity; D013431:Sulfates / Q000494:pharmacology*
D065607:Cytochrome P-450 Enzyme Inhibitors; D005609:Free Radicals; D007527:Isoenzymes; D013431:Sulfates; C004850:sodium dithionate; D010100:Oxygen
Issledovanie inaktivatsii vosstanovlennykh ditionitom natriia tsitokhromov P-450 razlichnogo proiskhozhdeniia.