Substrate stabilization: genetically controlled reciprocal relationship of two human enzymes.
5-Phosphoribosyl-l-pyrophosphate, a substrate shared by adenine phosphoribosyltransferase and hypoxanthine-guanine phosphoribosyltransferase, accumulates in human erythrocytes lacking hypoxanthine-guanine phosphoribosyltransferase. 5-Phosphoribosyl-l-pyrophosphate added to purified adenine phosphoribosyltransferase stabilizes it against heat inactivation. The increased activity of adenine phosphoribosyltransferase seen in erythrocytes deficient in hypoxanthine-guanine phosphoribosyltransferase may result from substrate stabilization of this enzyme in vivo.
D004905:Erythrocyte Aging; D004912:Erythrocytes / Q000201:enzymology*; D005954:Glucosephosphate Dehydrogenase / Q000097:blood; D006801:Humans; D008661:Metabolism, Inborn Errors / Q000097:blood / Q000201:enzymology*; D008967:Molecular Biology; D014166:Transferases / Q000097:blood* / Q000378:metabolism
D005954:Glucosephosphate Dehydrogenase; D014166:Transferases