Calculation of immobilized enzyme reaction progress curves from nested ordered-sequential rate expressions

A method for estimating immobilized enzyme reaction progress curves, using simultaneous non-linear regression analysis of 2-3 substrate concentrations with time, is presented. These facile procedures involve using nested Gaus s-Newton curve fitting algorithms on a Microsoft EXCEL spreadsheet. We refe r to our technique as "nested" because the analysis consists of two or thre e mutually parameter-dependent sets of computations associated with bi- or termolecular enzyme-catalyzed reactions, respectively. We have applied the method to immobilized glucose oxidase-catalyzed reactions ([D-glucose] and [O-2] with time) and found that the kinetic parameters from initial velocit y data were similar to those determined by the nested curve fitting method discussed herein. (C) 1999 Elsevier Science Inc. All rights reserved.