Effect of sulfhydryl reagents on mevalonate kinase partially purified from chicken liver

Abstract

Unlike other vertebrate mevalonate kinase, the enzyme partially purified from neonatal chick liver was not activated by the -SH group protectors reduced glutathione, cysteine, dithiothreitol and beta-mercaptoethanol at any concentrations assayed (0.01-10.00 mM).However, the activity was found to be sensitive to thiol group binding reagents.p-Hydroxymercuribenzoate was the most active inhibitor.At 0.1 mM concentration, p-HMB completely abolished the enzyme activity.N-ethylmaleimide (0.01-1.00 mM) was practically ineffective.Inhibition by p-HMB was temperature dependent, being more potent at 37 degrees C than at 4 degrees C.