[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.
Mokhosoev
I M
IM
Kuznetsova
G P
GP
Al'terman
M A
MA
Bachmanova
G I
GI
Archakov
A I
AI
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.