Exponential model for a regulatory enzyme. Computer program for the determination of the model constants from initial...

The paper describes a program (DESCENT) which evaluates the constants of the exponential model for a regulatory enzyme with up to four substrates or up to three substrates and one effector. The program operates by repetitive adjustment of the model constants so as to secure a better fit between the observed and calculated initial velocities of reaction. At each adjustment, all the constants are incremented simultaneously by amounts determined by a steepest descent criterion. The program is tested by artificial data with and without added error and it is shown that good estimates of the constants can be recovered.