acid-phosphatase and ribose-1-phosphate

Spontaneous decomposition of 5-phosphoribosyl 1-pyrophosphate at pH 5.5 was established to occur as follows: 5-Phosphoribosyl 1-pyrophosphate----5-phosphoribosyl 1,2-(cyclic)phosphate----ribose 1-phosphate----ribose Enzymic degradation of 5-phosphoribosyl 1-pyrophosphate by alkaline phosphatase from calf intestine and by acid phosphatases from potato and Aspergillus niger was found to proceed according to this pathway within the pH range 2.5-7.4 with accumulation of ribose 1-phosphate. In the case of alkaline phosphatase, Mg2+ ions inhibit the pyrophosphorolysis of 5-phosphoribosyl 1-pyrophosphate and stimulate the hydrolysis of ribose 1-phosphate.

Topics: Acid Phosphatase; Alkaline Phosphatase; Animals; Aspergillus niger; Cattle; Hydrogen-Ion Concentration; Hydrolysis; Hypoxanthine Phosphoribosyltransferase; Inosine; Intestines; Phosphoribosyl Pyrophosphate; Phosphoric Monoester Hydrolases; Ribosemonophosphates; Solanum tuberosum