THE BIOSYNTHESIS OF TREHALOSE PHOSPHATE

Abstract

The participation of uridine diphosphate glucose in the biosynthesis of disaccharides was first demonstrated by the discovery of an enzyme in yeast (1) which catalyzes the formation of trehalose phosphate according to the reaction UDPGi + glucose B-phosphate ---) UDP + trehalose phosphateThe present paper reports a partial purification of the enzyme and a detailed study of the reaction. MaterialsUDPG was prepared as described by Pontis et al. ( 2).Part of this material was kindly furnished by Dr. H. G. Pontis.UDP was prepared by heating UDPG at 100" in 0.03 N sulfuric acid for 10 minutes, followed by neutralization with barium hydroxide and chromatography on Whatman No. 3 paper with ethanol-ammonium acetate at pH 3.8 as solvent (3).Another sample of UDP was obtained by ion exchange chromatography of an alcoholic yeast extract, followed by paper chromatography as above.Phosphopyruvate was a gift of Dr. A. Kornberg.A crystalline sample of barium trehalose phosphate was generously provided by Dr. W. T. J. Morgan and one of crystalline albumin by Dr. D. Nachmansohn.Crystalline barium glucose g-phosphate was obtained from the Sigma Chemical Company, St. Louis, and intestinal phosphatase from Armour and Company, Chicago.The phosphatase was dialyzed overnight against cold distilled water before use.Glucose-6-phosphate dehydrogenase was purified according to Kornberg and Horecker (4).UDPG dehydrogenase was obtained as described by Strominger et al. (5).The purification was carried on until the first ammonium sulfate