Redox potentials P450 control

P450 saturated with substrates are reduced much faster than in the substrate-free state because of the positive shifts of the redox potential hy 100mV. Such control over the rate of the first electron transfer hy the substrate binding represents an important feature of the overall steady-state kinetics of many cytochromes P450 although some isozymes exist in a predominantly high-spin state, even without substrates, and they presumably lack this switch. 

Das A, Grinkova YV, Sligar SG (2007) Redox potential control by drug binding to cytochrome P450 3A4. J Am Chem Soc 129 13778-13779... 

Sligar SG, Cinti DL, Gibson GG, Schenkman JB (1979) Spin state control ofthe hepatic cytochrome-P450 redox potential. Bioehem Biophys Res Com-mun 90 925-932... 

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