Effects of aging on the various steps of protein synthesis:: Fragmentation of elongation factor 2
Effects of aging on the various steps of protein synthesis:: Fragmentation of elongation factor 2
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DOI：
10.1016/s0891-5849(98)00202-0
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发表时间：
1999-02-01
影响因子：
7.4
通讯作者：
Machado, A
中科院分区：
文献类型：
--
作者：
Parrado, J;Bougria, M;Machado, A
研究了衰老过程中体内蛋白质合成下降的可能机制。为了确定衰老对蛋白质合成各个步骤的影响，我们测定了大鼠肝脏蛋白质合成过程中核糖体的聚集状态和多肽链的组装和释放时间。结果表明，延伸率是对老化最敏感的步骤。延伸因子2（EF-2），参与延伸步骤的主要蛋白质的分子研究表明，这种蛋白质具有较高的羰基含量，在老年大鼠中活性较低。此外，EF-2的分子量分析表明，这种蛋白质在老年大鼠中变得片段化。在遭受氧化应激的3个月大的大鼠中发现了类似的片段化模式，因为蛋白质合成的下降与老年大鼠中发现的相似。这些数据表明：i）氧化应激似乎涉及在衰老期间观察到的EF-2的修饰，和ii）观察到的EF-2的修饰（氧化和片段化）可以解释老年动物中蛋白质合成的下降。(C)1998年爱思唯尔科学公司
The possible mechanism responsible for the in vivo protein synthesis decline during aging was studied. In order to determine the effect of aging on the various steps of protein synthesis, we determined the ribosomal state of aggregation and the time of assembly and release of polypeptide chains in the process of protein synthesis in rat Liver. The results suggest that elongation is the most sensitive step to aging. A molecular study of the Elongation Factor 2 (EF-2), the main protein involved in the elongation step, shows that this protein has a higher content of carbonyl groups and is less active in old rats. In addition, the molecular mass analysis of EF-2 shows that this protein becomes fragmented in old rats. A similar pattern of fragmentation is found in 3-month-old rats suffering oxidative stress, in that the decline in protein synthesis is similar to that found in old rats. These data suggest that: i) oxidative stress seems to be involved in the modifications of EF-2 observed during aging, and ii) the observed modifications (oxidation and fragmentation) of EF-2 could account for the decline in protein synthesis in old animals. (C) 1998 Elsevier Science Inc.