PT  - JOURNAL ARTICLE
AU  - Nath, Abhinav
AU  - Atkins, William M.
TI  - A Theoretical Validation of the Substrate Depletion Approach to Determining Kinetic Parameters
AID  - 10.1124/dmd.106.010777
DP  - 2006 Sep 01
TA  - Drug Metabolism and Disposition
PG  - 1433--1435
VI  - 34
IP  - 9
4099  - http://dmd.aspetjournals.org/content/34/9/1433.short
4100  - http://dmd.aspetjournals.org/content/34/9/1433.full
SO  - Drug Metab Dispos2006 Sep 01; 34
AB  - The substrate depletion approach is an increasingly popular alternative to the traditional method (observing product formation) of determining the kinetic parameters (KM and Vmax) of an enzyme. Obach and Reed-Hagen (Drug Metab Dispos 30:831–837, 2002) used an empirical relationship between substrate depletion rate constants and initial substrate concentration to determine kinetic parameters for a number of cytochrome P450-catalyzed reactions. We present a proof that this relationship can be derived from the Michaelis-Menten equation and, therefore, that kinetic parameters obtained by the substrate depletion approach are equivalent and comparable to those obtained by the traditional product formation approach. Analysis of a simulated data set produced similar kinetic parameters regardless of which approach was used, confirming the theoretical result. The American Society for Pharmacology and Experimental Therapeutics