RT Journal Article
SR Electronic
T1 A Theoretical Validation of the Substrate Depletion Approach to Determining Kinetic Parameters
JF Drug Metabolism and Disposition
JO Drug Metab Dispos
FD American Society for Pharmacology and Experimental Therapeutics
SP 1433
OP 1435
DO 10.1124/dmd.106.010777
VO 34
IS 9
A1 Abhinav Nath
A1 William M. Atkins
YR 2006
UL http://dmd.aspetjournals.org/content/34/9/1433.abstract
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