(481f) Kinetics of the Multienzyme System-Alcohol, Aldehyde and Lactate Dehydrogenase-for the Metabolism of Ethanol to Acetate

The multienzyme system, ethanol, acetaldehyde and lactate dehydrogenase, was studied for the metabolism of ethanol to acetate via acetaldehyde. This system employs pyruvate and lactate dehygrogenase to enable high turnover recycling of the cofactor NAD by converting NADH produced by ADH (alcohol dehydrogenase) and ALDH (acetaldehyde dehydrogenase) to NAD. The kinetic behavior of this three enzyme system was found to be affected by the NAD/NADH ratio, which in turn was affected by the LDH/ADH and LDH/ALDH enzyme ratios. Acetaldehyde and NADH were found to inhibit kinetic activity. Multienzyme kinetic simulation was found to be effective in interpreting this three enzyme system.