Electron Transfer from Cytochrome b5 to Cytochrome P450
There are four electron carriers in the endoplasmic reticulum of liver cells, two flavoproteins: NADH cytochrome b5 reductase (FP1) and NADPH cytochrome P450 reductase (FP2) and two hemoproteins: cytochrome b5 and cytochrome P450. The two reductases were first evidenced in 1950 by Hogeboom and Schneider (1) by their strong cytochrome c reductase activity. They were isolated respectively by Spatz and Strittmatter (2) and Van der Hoeven and Coon (3). The cytochrome b5 was described by Strittmatter and Ball (4). It was isolated after tryptic digestion of microsomes (5) and then purified with full length protein chain by Spatz and Strittmatter (6). The last electron carrier discovered in microsomes was cytochrome P450, the CO-binding pigment evidenced by Klingenberg (7) and Garfinkel (8) in 1958.
KeywordsLiver Microsome Reconstituted System Stop Flow Method Monooxygenase Reaction Rabbit Liver Microsome
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- 9.Y. Yassukochi and B.S.S. Masters, Some properties of a detergent solubilized NADPH-cytochrome c (cytochrome P450) reductase purified by biospecific affinity chromatography, J.Biol. Chem., 251:5337 (1976).Google Scholar
- 11.S.D. Black and M.J. Coon, P450 Sructure and Function, in: “Advances in Enzymology”, A. Meister, ed., John Willey, N.Y., 60:35 (1987).Google Scholar
- 12.R. Sato and T. Omura, “Cytochrome P450”, Kodansha, Tokio, Academic press, New-York, San Francisco, London (1978).Google Scholar
- 30.E.T. Morgan, D.R. Koop and M.J. Coon, Herne requirement in the effects of cytochrome b5 on catalytic activity of rabbit liver cytochrome P450, Fed. Proc., 40, 697 (1981).Google Scholar