Kinetic Model for a Threshold Filter in an Enzymatic System for Bioanalytical and Biocomputing Applications

TL;DR

This paper presents a kinetic model explaining a biochemical threshold filtering mechanism involving malate dehydrogenase, validated with experimental data, and clarifies the role of enzyme inhibition and product conversion in filtering behavior.

Contribution

The study introduces a novel kinetic model incorporating reversible enzyme inhibition to explain biochemical threshold filtering, supported by experimental validation.

Findings

Reversible enzyme inhibition is key to threshold filtering.

Fast reversible product conversion alone does not produce filtering.

The model accurately fits experimental data for malate dehydrogenase.

Abstract

A recently experimentally observed biochemical "threshold filtering" mechanism by processes catalyzed by the enzyme malate dehydrogenase is explained in terms of a model that incorporates an unusual mechanism of inhibition of this enzyme that has a reversible mechanism of action. Experimental data for a system in which the output signal is produced by biocatalytic processes of the enzyme glucose dehydrogenase are analyzed to verify the model's validity. We also establish that fast reversible conversion of the output product to another compound, without the additional inhibition, cannot on its own result in filtering.