Fluorescent energy transfer measurements on fluorescein isothiocyanate modified cytochrome P-450 LM2.
The distance between the heme iron and the N-terminus of cytochrome P-450 LM2 was determined by fluorescence energy transfer measurements. Fluorescein isothiocyanate which was covalently bound to the N-terminal methionine was used as donor chromophor. The Ro value between fluorescein isothiocyanate and the heme was calculated to be 3.98 nm. The distance between the nitrogen of the N-terminal methionine and the heme was estimated with 2.84 +/- 0.23 nm excluding most likely the N-terminal amino acid of cytochrome P-450 LM2 to participate in the electron transfer to the heme iron. A cytochrome P-450 LM2 membrane model is proposed.
D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004735:Energy Transfer; D016650:Fluorescein-5-isothiocyanate; D005452:Fluoresceins / Q000378:metabolism*; D008297:Male; D008433:Mathematics; D008862:Microsomes, Liver / Q000201:enzymology; D008958:Models, Molecular; D011817:Rabbits; D013050:Spectrometry, Fluorescence; D013861:Thiocyanates / Q000378:metabolism*
D005452:Fluoresceins; D013861:Thiocyanates; D003577:Cytochrome P-450 Enzyme System; D016650:Fluorescein-5-isothiocyanate