Does total microsomal protein concentration affect enzyme activity?
Differences in total protein concentration can affect the free concentration of substrate and hence cytochrome P450 enzyme kinetics. The available substrate concentration may be significantly lower than initially assumed for those substrates which have a large potential to bind to protein or microsomal membranes. (Obach et al. (1997) J. Pharmacol. Exp. Ther. 283, 46-58 and RS Obach (1997) Drug Metab. Dispos. 25, 1359-69) Total microsomal protein concentration can be controlled and normalized in each incubation by the addition of control microsomes.
