An enzyme rate equation for the overall rate of reaction of gel‐immobilized glucose oxidase particles under buffered conditions. I. Pseudo‐one substrate conditions

Abstract

SummaryThe overall rate of reaction of buffered gel-immobilized glucose oxidase particles is described by means of an enzyme rate equation which relates the overall reaction rate of a particle to the free solution characteristics of the enzyme, the effective diffusivity of the limiting substrate in the gel, the characteristic particle size, and the limiting substrate concentration adjacent to the gel surface. This equation accounts quantitatively for the limitation of the overall rate of reaction by substrate diffusion, and it is used to illustrate the influence of the system parameters, i.e., particle size, enzyme concentration, and pH, on the extent of the diffusional resistance associated with gel-immobilized glucose oxidase particles.The enzyme rate equation is generally applicable to those enzymes whose kinetics approximately follow Michaelii-Menten form when in free solution.

Analytical aspects of immobilized enzyme columns

“…Third, internal diffusion time could be decreased. Both of these mass transfer effects would increase the catalyst's effectiveness factor (53,54). Such studies were not done here because 200-400 mesh glass is the smallest controlled pore material available at this time.…”

Diffusion and the limiting substrate in two‐substrate immobilized enzyme systems

“…(3), integrating twice, and applying the boundary conditions [eqs. (4)- (6)], we obtain C2 = Fl + A (9) where A is the following integration constant:…”

Investigations of Reaction Kinetics for Immobilized Enzymes—Identification of Parameters in the Presence of Diffusion Limitation

“…Depending on the enzyme loading and the substrate to be converted, biocatalysis with immobilized preparations of such enzymes may become diffusion limited. The classic methodology to identify kinetic parameters of highly active immobilized enzyme preparations consists of the following (e.g., 8−10): (1) determination of the intrinsic parameters on the basis of experiments with free soluble enzyme; and (2) adjusting the maximum catalytic velocity ( v max ) to compensate for the loss of enzyme activity upon immobilization and efficiency due to, for example, the extent of enzyme loading.…”