Selective chemical modification of a functionally linked lysine in cytochrome P-450 LM2.
Fluorescein isothiocyanate (FITC) has been selectively bound to the epsilon-amino group of lysine-382 in cytochrome P-450 LM2 (RH, reduced-flavoprotein: oxygen oxidoreductase (RH-hydroxylating), EC 1.14.14.1) at pH 8.15. Benzphetamine N-demethylase activity of the reconstituted FITC-modified cytochrome P-450 LM2 was inhibited by 25%. This inhibition has been shown to be due to an impaired electron transfer from the NADPH-cytochrome P-450 reductase (NADPH: ferricytochrome oxidoreductase, EC 1.6.2.4) to the haemoprotein. The data indicate that cytochrome P-450 interacts with the flavoprotein via electrostatic interactions.
D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004579:Electron Transport; D016650:Fluorescein-5-isothiocyanate; D005452:Fluoresceins / Q000378:metabolism / Q000494:pharmacology; D005456:Fluorescent Dyes; D008239:Lysine; D008297:Male; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D010089:Oxidoreductases, N-Demethylating / Q000037:antagonists & inhibitors; D010446:Peptide Fragments; D011817:Rabbits; D051381:Rats; D013053:Spectrophotometry; D013329:Structure-Activity Relationship; D013861:Thiocyanates / Q000378:metabolism / Q000494:pharmacology
D005452:Fluoresceins; D005456:Fluorescent Dyes; D010446:Peptide Fragments; D013861:Thiocyanates; D003577:Cytochrome P-450 Enzyme System; C019781:benzphetamine N-demethylase; D010089:Oxidoreductases, N-Demethylating; D009251:NADPH-Ferrihemoprotein Reductase; D016650:Fluorescein-5-isothiocyanate; D008239:Lysine