Function and fidelity of aging tRNA: in vivo acylation, analog discrimination, synthetase binding, and in vitro translation.

The liver transfer RNAs for valine and lysine were completely acylated in vivo, as judged by periodate oxidation, at 4 and 24 months of age in male Sprague-Dawley rats. In vitro acylation capacity for whole tRNA populations from rat livers is decreased, but this is evidently not deleterious in vivo. Several halogenated phenylalanines were synthesized and their effects upon acylation capacity for phenylalanine were examined.