N-ethyl-maleimide alkylation converts ferric P450cam to a (succinimido-cys)4 protein with native optical and EPR spectra but insensitive to substrate induced shift of iron to high spin with Soret absorption to higher energy and inactive in putidaredoxin ferric-ferrous reduction. On photo or chemical reduction the ferrous protein oxygenates and, with reduced putidaredoxin, converts substrate to product. Mild oxidation of P450cam yields a disulfide dimer whose properties on alkylation of 3 sulfhydryls equal the succinimido4 monomer; additional alkylation converts either monomer or dimer to a P420.
|Original language||English (US)|
|Number of pages||8|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Aug 14 1978|
Bibliographical noteFunding Information:
Supported in part by HEW PHS Grants GM 21161 and AM 00562. We are indebted to Dr. B. S. Shastry for checking the cysteinyl and succinimido-cysteine content of the NEM treated cyt m.