title: Developmental expression of murine HPRT. I. Activities, heat stabilities, and electrophoretic mobilities in adult tissues.
abstract: Total and specific activity of the enzyme hypoxanthine phosphoribosyltransferase (HPRT) varied widely among six tissues from C3H/f mice; the highest levels of activity were in brain. More striking were thermostability differences in tissue enzymes. Although brain, spleen, and kidney HPRT retained 65% basal activity after 15 min at 85 C, heart, liver, and erythrocyte HPRT retained only 20-30% initial activity. Kidney HPRT behaved as monospecific heat-stable enzyme (K-denatauration=0.022/min, and liver enzyme behaved as monospecific heat-labile enzyme (K-denaturation=0.061/min), while other tissues appeared to contain both forms of the enzyme. Multiple electrophoretic activity bands were present in all tissues; no activity band was restricted to a single tissue. The data presented here are consistent with the hypothesis that the distinct tissue properties of HPRT result from posttranslational modification of the product of a single genetic locus which is expressed in all tissues.
mesh_terms: D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000201:enzymology; D004247:DNA / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000201:enzymology; D007041:Hypoxanthine Phosphoribosyltransferase / Q000378:metabolism*; D007668:Kidney / Q000201:enzymology; D008099:Liver / Q000201:enzymology; D051379:Mice; D008809:Mice, Inbred C3H / Q000378:metabolism*; D009206:Myocardium / Q000201:enzymology; D011489:Protein Denaturation; D013154:Spleen / Q000201:enzymology
chemical_list: D004247:DNA; D007041:Hypoxanthine Phosphoribosyltransferase