Sushkova V V, Gulyĭ M F, Vysotskaia O V
Ukr Biokhim Zh. 1976;48(6):717-20.
The effect of the D,L-tryptophan excess in the rat organism was studied as applied to the level of amino acylation of tRNA by 14C-tryptophan. It is established that the introduction of tryptophan for three days in doses of 50 and 75 mg per 100 g of the living weight evokes a 24 and 40% decrease, respectively, in the level of amino acylation of the rat livel tRNA by 14C-tryptophan. The ability of accepting 14C-tryptophan in total preparations of the experimental rats liver tRNA considerably lower as compared to norm. A short-term heating in the presence of magnesium ions partially restores their decreased acceptor ability. This gives ground to suppose that the molecules of tRNAtr in the total preparation of the rat liver tRNA with a great tryptophan excess in the organism partially change their conformation and this is one of the reasons of the decrease in the level of tRNA amino acylation by 14C-tryptophan. The decrease in the protein synthesis at the first stage with the presence of a great tryptophan excess in the organism is evident to be also connected with the inhibition of tryptophanyl-tRNA-synthetase activity.
研究了大鼠机体中D，L -色氨酸过量对14C -色氨酸使tRNA氨酰化水平的影响。结果表明，以每100克体重50毫克和75毫克的剂量给大鼠连续三天注射色氨酸，会使大鼠肝脏tRNA的14C -色氨酸氨酰化水平分别降低24%和40%。与正常情况相比，实验大鼠肝脏tRNA总制剂接受14C -色氨酸的能力显著降低。在镁离子存在下进行短期加热可部分恢复其降低的接受能力。这使我们有理由推测，在机体色氨酸大量过量的情况下，大鼠肝脏tRNA总制剂中的tRNAtr分子部分改变了其构象，这是14C -色氨酸使tRNA氨酰化水平降低的原因之一。在机体色氨酸大量过量的情况下，蛋白质合成在第一阶段的减少显然也与色氨酰 - tRNA合成酶活性的抑制有关。
