Transfer ribonucleic acid of vitamin A-deficient rats

Abstract

The effect of vitamin A deficiency on the chromatographic elution patterns of liver tRNA from BD-cellulose was investigated. The tRNA and aminoacyl-tRNA synthetase enzymes were prepared from the liver of normal (control) and vitamin A-deficient rats. Following deacylation, tRNA from both sources was charged with an l-[³H]-amino acid mixture using homologous and heterologous synthetase preparations. The tRNA was also charged individually with the two essential amino acids, l-[³H-methyl]methionine and l-[³H] phenylalanine, using homologous synthetase enzymes. The elution profiles of labeled aminoacyl tRNA's from BD-cellulose columns were subsequently determined. The degree of acylation of tRNA from vitamin A-deficient rats was always greater than that of normal tRNA, regardless of the source of enzyme preparation. The elution patterns from BD-cellulose of charged tRNA showed that synthetases from deficient animals acylate certain normal tRNA species which normal enzymes seem not to acylate, and that normal synthetases also acylate distinct vitamin A-deficient tRNA species. Furthermore, the elution pattern of normal tRNA^phe differed from that of deficient tRNA^phe in the number of eluted peaks and in their relative elution position. Whereas, in the normal case, two tRNA^met peaks were eluted in the deficient state, only one tRNA^met peak was observed.