RT Journal Article
SR Electronic
T1 Dithionite-supported hydroxylation of palmitic acid by cytochrome P450BM-3.
JF Drug Metabolism and Disposition
JO Drug Metab Dispos
FD American Society for Pharmacology and Experimental Therapeutics
SP 1282
OP 1285
VO 24
IS 11
A1 X Fang
A1 J R Halpert
YR 1996
UL http://dmd.aspetjournals.org/content/24/11/1282.abstract
AB The ability of dithionite, an inexpensive reducing agent routinely used to produce the ferrous-carbonyl form of P450, to support P450BM-3-catalyzed hydroxylation of palmitate was studied. The hydroxylation products in the presence of dithionite were 15, 14, and 13-hydroxyhexadecanoate, with relative distributions similar to those observed with NADPH. The hydroxylation reaction was carried out in two separate steps, anaerobic reduction and subsequent oxidation of P450BM-3 by oxygen bubbling. The reduction step was much slower than the oxidation step, thus limiting the overall rate of hydroxylation. Upon addition of dithionite, the reductase domain of P450BM-3 seemed to be reduced before significant reduction of the heme domain occurred. The discovery of new reducing agents for P450-catalyzed reaction raises the possibility of replacing NADPH in specialty chemical hydroxylation catalyzed by P450s, especially catalytically self-sufficient P450s, such as P450BM-3 or recombinant fusion proteins of P450 covalently linked to a reductase.