Acyl phosphate: Hexose phosphotransferase

Purification, characterization and initial rate kinetics of acyl-phosphate-hexose phosphotransferase from Aerobacter aerogenes

“…This portion of the product-time progress curve was determined either from continuous spectrophotometric tracings or by a series of stop-time 14b âterminatlons when the former procedure could not be used, i.e., for Kamel and Anderson (1967). Although the enzyme was purified to the point where it was free of contaminating activities, the enzyme was not homogeneous.…”

“…The copurification of these two activities in a constant ratio under standardized conditions, the similarity of the Michaelis constants for both the phosphotransferase and phosphohydrolase reactions, and the Inhibition of the phosphatase activity by glucose provide strong evidence that both activities reside on the same enzyme (Kamel and Anderson, 1967).…”

“…Soon after the discovery of this enzyme it was reported that acyl-phosphate-hexose phosphotransferase was responsible for a wide variety of phosphotransferase and phosphohydrolase reactions (Kamel and Anderson, 1967;Bergmeyer and Moellering, 1965). Table 1 lists some representative substrates for both the phosphotransferase and the phosphohydrolase reactions.…”

“…At present, there are at least four other enzymes which are known to display both a transferase and a hydrolase activity. They are glucose 6-phosphatase (Arion and Nordlie, 1964), transglutaminase (Gross and Folk, 1973) and y-glutamyltranspeptidase (Schuber et al, 1976 Kamel and Anderson (1967) and Bergmeyer and Moellering (1965).…”

“…Glucose 6-phosphatase also catalyzes a hexose phosphate-hexose phosphotransferase reaction (Hass and Byrne, 1960;Segal, 1959). Notably, nucleoside polyphosphates and pyrophosphate are substrates for glucose 6-phos phatase (Nordlie, 1971), but not for acyl-phosphate-hexose phospho transferase (Bergmeyer and Moellering, 1965;Kamel and Anderson, 1967).…”