ESTIMATING THE PARAMETERS OF THE MICHAElIS - MENTEN EQUATION USING SAS

The Michaelis-Menten equation, a rectangular hyperbola with two ~arameters ~o b~ specified, . occurs prominently 1n enzyme k,netlcs." Often, ~n consulting situations we need to (i) obtain estlmates standard errors, and confidence intervals for the unknown parameters, which define this nonlinear model for one set of experimental conditions and (ii) compare the parameter estimates under different experimental conditions~ Parameter estimates for this nonlinear model can be obtained using least square normal theory~ the regular jackknife, the linear jackknife or the weighted ]jnear jackknife. In addition, the jackknife procedures allow one to evaluate differences in the parameter estimates across several experiments. The purpose of this paper is to demonstrate the ease in which these techniques are implemented using several SAS macros. These techniques are applied to an experiment which was run to determine if lipid concentrations selectively affected the maximal velocity parameter but not the Michaelis constant for a partlcular enzyme reaction. Empirical results.are compared and the weighted linear jackknife for the nonlinear model seems to be the best procedure in achieving the objective of the data analytic probl em.