Phosphoribosylpyrophosphate synthetase in human erythrocytes: assay and kinetic studies using high-performance liquid chromatography.

A method using high-performance liquid chromatography (HPLC) for determination of phosphoribosylpyrophosphate (PRPP) synthetase activity in human erythrocytes has been developed and PRPP synthetase activity on purine and pyrimidine metabolic disorders has been studied. Kinetic properties of erythrocyte PRPP synthetase of patients with gout and of a patient with pyrimidine 5'-nucleotidase deficiency were compared with those of healthy subjects. The mean of PRPP synthetase activity of gouty patients was a little higher (P less than 0.01) than that of healthy subjects. The response of the enzyme for ATP of gouty patients was different from that of healthy subjects. The shapes of activation curve of the enzyme for inorganic phosphate were hyperbolic in gouty patients and in a patient with pyrimidine 5'-nucleotidase deficiency.