A method for conforming the pH dependence of the michaelis parameters of nonallosteric enzymes to four kinetic schemes.

ABSTRACT

A nonlinear regression program for the analysis of the effect of pH on enzyme activity has been developed for the IBM micro range and compatible machines. The program conforms the V and Km pH profiles to one of four commonly occurring kinetic schemes. By using multiple linear regression the program computes initial estimates for the nonlinear search which are thus not required from the user. Two nonlinear optimization methods are included in order to effectively handle the nonnegativity constraints on the parameters. The program is user-friendly and provides plots of the fit and residual plots to help the user decide on the goodness of fit obtained. The program was coded in Turbo Pascal version 4.0 and runs on IBM micros or close compatibles with four types of graphics cards.