Phosphoramidates

Abstract

Abstract An enzyme, catalyzing phosphoryl transfers from phosphoramidate or from various hexose phosphates, has been purified to a high degree from extracts of Escherichia coli. The purification involves the preferential denaturation of contaminating proteins at acid and at alkaline pH values, followed by chromatography on Biogel P-20, carboxymethyl cellulose, and diethylaminoethyl cellulose. The resulting enzyme is essentially homogeneous as shown by acrylamide gel electrophoresis and sucrose gradient centrifugation. It is capable of transferring phosphoryl groups from phosphoramidate and from several hexose phosphates to a variety of hexose (glucose, fructose, and mannose) acceptors and also to water. The pH optima, inhibitor specificities, and characteristics of the various reactions catalyzed by the enzyme are reported.