# Enzymes helping enzymes: Oxaloacetate decarboxylase increases malate dehydrogenase's turnover number

## TL;DR

One enzyme can boost another enzyme's speed by using its product, showing that enzymes can work together to improve reactions.

## Contribution

The study reveals that the presence of a second enzyme can triple the catalytic rate of another enzyme through product interaction.

## Key findings

- The initial rate of an enzyme increases 3-fold when another enzyme uses its product.
- The enhancement may come from allosteric effects or product competition between enzymes.

## Abstract

The catalytic performance of enzymes is largely perceived to be a property of the enzyme itself, altered by environmental conditions, such as temperature and pH. However, the maximal catalytic rates of enzymes differ up to 100-fold between in vivo and in vitro measurements, suggesting that a complex chemical system has additional effects on catalytic performance. In this work, we show that the initial rate of an enzyme can increase 3-fold due to the presence of a second enzyme, which uses the product of the first enzyme as its substrate. This enhancement may originate in an allosteric effect or result from binding competition for the product molecule by the second enzyme.