title: Hypoxanthine phosphoribosyltransferase deficiency: association of reduced catalytic activity with reduced levels of immunologically detectable enzyme protein.
abstract: In the present study hemolysates from fourteen patients with a genetically determined deficiency of hypoxanthine phosphoribosyltransferase (EC 2.4.2.8; IMP:pyrophosphate phosphoribosyltransferase) activity were examined immunologically for the presence of material that crossreacts with the normal enzyme. A quantitative assay for crossreacting material in enzyme-deficient hemolysates was based on the inhibition of the immunoprecipitation of the normal enzyme. As little as 3% of normal crossreacting material could be detected. One patient in this series was found to have a normal amount of crossreacting material, whereas the remainder had no detectable crossreacting protein. The lack of detectable crossreacting material in these patients raises the possibility that a defect in synthesis or degradation of enzyme protein may be present in many patients deficient in hypoxanthine phosphoribosyltransferase.
mesh_terms: D004355:Drug Stability; D005615:Freezing; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000097:blood / Q000172:deficiency* / Q000276:immunology; D007926:Lesch-Nyhan Syndrome / Q000201:enzymology; D011233:Precipitin Tests; D011686:Purine-Pyrimidine Metabolism, Inborn Errors / Q000201:enzymology*; D013997:Time Factors
chemical_list: D007041:Hypoxanthine Phosphoribosyltransferase