Developmental expression of murine HPRT. I. Activities, heat stabilities, and electrophoretic mobilities in adult tissues
✍ Scribed by Yuen-Fong V. Lo; Roberta M. Palmour
- Publisher
- Springer
- Year
- 1979
- Tongue
- English
- Weight
- 442 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0006-2928
No coin nor oath required. For personal study only.
✦ Synopsis
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.