THE ENZYMATIC FORMATION OF HYDROXAMIC ACIDS FROM GLUTAMINE AND ASPARAGINE

作者：Nathan Grossowicz, Elsie Wainfan, Ernest Borek, Heinrich Waelsch · 发表于：Journal of Biological Chemistry · 年份：1950 · DOI：10.1016/s0021-9258(19)50936-x · 被引用次数：188 · 研究领域：Enzyme function and inhibition、Biochemical and Molecular Research、Amino Acid Enzymes and Metabolism

Although glutamine and asparagine have a wide distribution in nature, heretofore the only metabolic function ascribable to them on the basis of known enzymatic processes has been their participation in the metabolism of ammonia (1, 2).We have recently reported the formation of hydroxamic acids by the enzyme-catalyzed replacement of the amide groups of glutamine and asparagine with hydroxylamine (3-5).The same enzyme extract also catalyzes the exchange of the amide group of glutamine and asparagine with (isotopic) ammonia ( 6).The process would have considerable biological significance if it could be shown that amino acids can participate in an analogous reaction to form peptide bonds.The enzymatic formation of hydroxamic acids from glutamine and asparagine described here is different from the enzymatic synthesis of y-glutamohydroxamic acid from glutamic acid (7, 8).The latter reaction, which has been used as a model for glutamine synthesis, requires the utilization of adenosinetriphosphate as an external source of energy, whereas the formation of y-glutamo-and /3-aspartohydroxamic acids from the corresponding amides proceeds without the utilization of energy-rich phosphate bonds.The enzyme preparations which synthesize the hydroxamic acids from the amides and hydroxylamine can also split hydroxamic acids.The enzyme systems are widely distributed in microorganisms.In the present report the enzymatic synthesis of glutamo-and aspartohydroxamic acids from the two natural amides b...