Purification and Properties of the L-Cysteinyl Ribonucleic Acid Synthetase of Bakers' Yeast

Abstract

In this report a method is described for the puritication of the L-cystemyl-RNA synthetase of Bakers' yeast.The enzyme, which was purified approximately 710-fold, was shown to have a molecular weight of approximately 160,000, and did not contain activity for any of the ammo acids commonly occurring in protein except L-cysteine.Optimum conditions for enzyme activity, such as substrate concentration, ion requirements, temperature, and pH were determined.Catalytic activity of the synthetase was not impaired by p-chloromercuribenzoate or iodoacetamide.