title: Purification of IMP:pyrophosphate phosphoribosyltransferases, catalytically incompetent enzymes in Lesch-Nyhan disease.
abstract: IMP:pyrophosphate phosphoribosyltransferase (IPPase) (EC 2.4.2.8) has been purified over 7000-fold from human erythrocytes. The purified enzyme moved as a single band on disc electrophoresis. Antisera prepared in rabbits and rats against the purified enzyme precipitated and neutralized the enzyme, but had no effect on AMP-pyrophosphate phosphoribosyltransferase (EC 2.4.2.7) activity. Evidence was found for isozymes (enzyme variants) of IPPase in normal erythrocytes. Erythrocyte lysates of five patients with Lesch-Nyhan disease reacted with antisera against normal IPPase. Lysates from LN erythrocytes blocked the inactivation of normal enzyme by the antibody. LN erythrocytes had about the same concentration of enzyme protein as normal erythrocytes. The genetic defect in LN results in the production of essentially normal amounts of an immunologically identifiable but catalytically incompetent enzyme. Thus LN is apparently the result of a mutation in a structural gene and is not due to deletion of a structural gene or defect in a regulatory gene.
mesh_terms: D000227:Adenine Nucleotides; D000818:Animals; D001264:Athetosis / Q000201:enzymology*; D002247:Carbon Isotopes; D011232:Chemical Precipitation; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D003429:Cross Reactions; D011756:Diphosphates; D004355:Drug Stability; D004589:Electrophoresis, Disc; D004912:Erythrocytes / Q000201:enzymology; D005796:Genes; D006358:Hot Temperature; D006801:Humans; D007042:Hypoxanthines; D007106:Immune Sera / Q000302:isolation & purification; D007223:Infant; D008607:Intellectual Disability / Q000201:enzymology*; D007527:Isoenzymes / Q000302:isolation & purification; D007926:Lesch-Nyhan Syndrome / Q000097:blood / Q000201:enzymology; D009154:Mutation; D009500:Neutralization Tests; D009711:Nucleotides; D010428:Pentosephosphates; D011686:Purine-Pyrimidine Metabolism, Inborn Errors / Q000201:enzymology*; D000644:Quaternary Ammonium Compounds; D011817:Rabbits; D051381:Rats; D012652:Self Mutilation / Q000201:enzymology*; D013431:Sulfates; D014166:Transferases / Q000097:blood / Q000302:isolation & purification*
chemical_list: D000227:Adenine Nucleotides; D002247:Carbon Isotopes; D011756:Diphosphates; D007042:Hypoxanthines; D007106:Immune Sera; D007527:Isoenzymes; D009711:Nucleotides; D010428:Pentosephosphates; D000644:Quaternary Ammonium Compounds; D013431:Sulfates; D014166:Transferases