Influence of polyethylene glycol on lactate dehydrogenase

It is well established that polyethylene glycol (PEG) shifts the equilibrium in oligomeric protein systems to form higher molecular weight associates. We used this effect of PEG to evaluate a modification of functional properties of LDH from pig skeletal muscles. PEG decreases the rate of heating‐induced LDH inactivation in the concentration dependent manner. Michaelis constant and maximal velocity of the enzyme as well as inhibition of LDH by high pyruvate concentrations were affected by PEG. Enzyme preincubaion with PEG suppresses also the formation of ternary inactive complex NAD‐pyruvate‐LDH.