Transfer ribonucleic acid methylases of bone. Studies on vitamin A and D deficiency
| Autor: | David S. Bradford, Irwin Clark, Bruce Hacker |
|---|---|
| Rok vydání: | 1972 |
| Předmět: |
Male
Vitamin History chemistry.chemical_element Calcium Methylation Bone and Bones Education chemistry.chemical_compound Ribonucleases RNA Transfer Vitamin D and neurology Animals Magnesium Femur Ribonuclease Carbon Isotopes TRNA methylation Tibia biology Vitamin A Deficiency Body Weight Methyltransferases Articles Vitamin D Deficiency Rats Computer Science Applications Liver Biochemistry chemistry Transfer RNA biology.protein |
| Zdroj: | Biochemical Journal. 126:1057-1066 |
| ISSN: | 0306-3283 |
| DOI: | 10.1042/bj1261057a |
| Popis: | Methods were devised for the assay of tRNA methylases of rat bone. The activities of bone tRNA methylases are similar to those from other mammalian tissues. However, unlike reports on liver methylases, no inhibitors were found in the supernatant fraction from pH5 precipitate of bone extracts. The effects of vitamins A and D on the methylation of tRNA by cell-free extracts of rat bone were studied. Deficiency of either vitamin resulted in a decrease in the rate and extent of tRNA methylation, whereas the administration of vitamin A to hypovitaminotic-A rats and vitamin D to hypovitaminotic-D rats increased the rate and extent of tRNA methylation. These effects appear to be apart from changes in ribonuclease activity or in concentrations of calcium or magnesium. No evidence of inhibitors of tRNA methylases was found in bone extracts from vitamin-deficient rats nor of activators in bone extracts from deficient rats given vitamin A or D. The pattern of tRNA methylation under conditions of vitamin A or D deficiency was not changed, suggesting a generalized cellular deficiency. It was of significance to find that the specificity for methylation of specific bases in tRNA was different after the administration of vitamin A as contrasted with the effects of vitamin D. The possible significance of tRNA methylation to the biochemical action of the vitamins on bone is discussed. |
| Databáze: | OpenAIRE |
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