Glutathione Synthesis in Human Erythrocytes: <i>II. PURIFICATION AND PROPERTIES OF THE ENZYMES OF GLUTATHIONE BIOSYNTHESIS</i>

Philip W. Majerus; M. J. Brauner; M. B. Smith; Virginia Minnich

doi:10.1172/JCI106652

Glutathione Synthesis in Human Erythrocytes: II. PURIFICATION AND PROPERTIES OF THE ENZYMES OF GLUTATHIONE BIOSYNTHESIS

Published August 1, 1971 - More info

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Abstract

The two enzymes required to synthesize glutathione de novo have been purified from human erythrocytes. Glutamylcysteine synthetase was purified 4300-fold and was approximately 80% pure based on polyacrylamide gel electrophoresis. The purified enzyme catalyzes the formation of 30.5 μmoles of γ-glutamyl-cysteine per mg of protein per hr and is inhibited by sulfhydryl inhibitors.

Glutathione synthetase was purified 6000-fold from erythrocytes to homogeneity as determined by polyacrylamide gel electrophoresis. The erythrocyte enzyme has a molecular weight of 150,000 and catalyzes the formation of 35.9 μmoles of glutathione per mg of protein per hr. Comparison of the amino acid composition and some kinetic parameters of yeast glutathione synthetase and the erythrocyte enzyme demonstrate similarities between these enzymes.

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