Demidov S V, Berdysev G D, Kovalenko M I, Jelskaja A V
Z Alternsforsch. 1981;36(5):379-87.
The acceptor capacity of tRNAs and tRNA-synthetases activities of liver extracts was compared for rabbits of different age groups. The level of maximum tRNA aminoacylation in vitro of newborn rabbit (3-5 days) liver for glycine, glutamic acid, leucine, tryptophan, and phenylalanine and tRNA of old rabbits (5 years) liver for glutamic acid, leucine, phenylalanine, and glycine was 1,5-3 times lesser in comparison to that of 1 and 2 years rabbits. The pool of endogenous aminoacyl-tRNAs in 3-5 days rabbits liver was also considerably lower for above mentioned amino acids. The results of short-term heating of tRNA preparations in the presence of Mg2- given the possibility to assume that the decreases tRNA preparations in the presence of Mg2+ give the possibility to assume that the decreases tRNA acceptor activity of the newborn animals depends upon the presence of tRNA inactive conformers. Another reason is the greater loss of the CCA-end in mentioned tRNA. None of these factors in the reason of low acceptor activity of old rabbit liver tRNA which seems to be caused by more considerable disturbances in he molecular structure. Aminoacyl-tRNA-synthetases activities of liver extracts of the same age groups increases during development of animals and decrease subsequently in the liver of old (5 years) rabbits. However, dynamics and quantitative characteristics of these changes are not similar for enzymes of different amino acid specificities.
比较了不同年龄组兔子肝脏提取物中tRNA的接受能力和tRNA合成酶活性。新生兔（3 - 5天）肝脏中甘氨酸、谷氨酸、亮氨酸、色氨酸和苯丙氨酸的体外最大tRNA氨酰化水平，以及老年兔（5岁）肝脏中谷氨酸、亮氨酸、苯丙氨酸和甘氨酸的tRNA，与1岁和2岁兔子相比低1.5 - 3倍。对于上述氨基酸，3 - 5天龄兔子肝脏中内源性氨酰 - tRNA池也显著更低。在Mg2 +存在下对tRNA制剂进行短期加热的结果使我们有可能假设，新生动物tRNA制剂在Mg2 +存在下接受活性的降低取决于tRNA无活性构象体的存在。另一个原因是上述tRNA中CCA末端的更大损失。这些因素都不是老年兔肝脏tRNA接受活性低的原因，其似乎是由分子结构中更显著的紊乱引起的。相同年龄组动物肝脏提取物中氨酰 - tRNA合成酶活性在动物发育过程中增加，随后在老年（5岁）兔子肝脏中降低。然而，不同氨基酸特异性的酶在这些变化的动态和定量特征方面并不相似。
