MECHANISMS OF ACTION OF AMINOGLYCOSIDE ANTIBIOTICS IN EUKARYOTIC PROTEIN-SYNTHESIS
MECHANISMS OF ACTION OF AMINOGLYCOSIDE ANTIBIOTICS IN EUKARYOTIC PROTEIN-SYNTHESIS
复制标题
DOI：
10.1128/aac.26.1.53
复制
发表时间：
1984-01-01
影响因子：
4.9
通讯作者：
WILHELM, JM
中科院分区：
文献类型：
--
作者：
EUSTICE, DC;WILHELM, JM
嗜热四膜虫是一种真核生物，对氨基糖苷类抗生素的生长抑制高度敏感。巴洛霉素、庆大霉素G418和潮霉素B的浓度分别为22、10和17微米时，生长抑制率为50%。采用体外和体内相结合的方法，研究了这些氨基糖苷类抗生素对嗜热链霉菌蛋白质合成的作用机制。对用帕罗米星和庆大霉素G418处理的细胞进行的多聚体图谱分析显示，伴随着体内[14C]赖氨酸掺入的抑制，多聚体明显的进行性减少。在体外，帕罗霉素和庆大霉素G418是二取代的2-脱氧链胺分子，对多聚体上肽-tRNA的转位和新生多肽链的延长都不是很有效的抑制剂。Phe-tRNA在多聚尿苷程序核糖体上的转位易受帕罗霉素的抑制。显然，帕罗霉素和庆大霉素G418的主要抑制作用是在起始后的伸长早期、翻译的起始阶段或起始前的翻译阶段。潮霉素G是一种单取代的含2-脱氧链胺的氨基糖苷类化合物，它能有效地抑制多聚体翻译过程中新生链的伸长。来自2个潮霉素B抗性突变体的多聚体的体外翻译能抵抗潮霉素B引起的伸长抑制。
Tetrahymena thermophila is a eukaryotic organism that is highly susceptible to growth inhibition by aminoglycoside antibiotics. Concentrations of paromomycin, gentamicin G418, and hygromycin B at 22, 10 and 17 .mu.M, respectively, inhibited growth by 50%. A combination of in vitro and in vivo methods was used to determine the mechanisms of action of these aminoglycoside antibiotics on protein synthesis in T. thermophila. Analysis of polysome profiles from paromomycin- and gentamicin G418-treated cells showed clear, progressive depletions of polysomes concomitant with an inhibition of in vivo [14C]lysine incorporation. In vitro, paromomycin and gentamicin G418, which are disubstituted 2-deoxystreptamine-containing molecules, were not very effective inhibitors of either the translocation of peptidyl-tRNA or the elongation of nascent polypeptide chains on polysomes. The translocation of phe-tRNA on polyuridylate programmed ribosomes was susceptible to inhibition by paromomycin. Apparently, the primary inhibitory action of paromomycin and gentamicin G418 was at an early stage of elongation after initiation, the initiation stage of translation, or a stage of translation before initiation. Hygromycin G, which is a monosubstituted 2-deoxystreptamine-containing aminoglycoside, potently inhibited the elongation of nascent chains during the translation of polysomes. The in vitro translation of polysomes from 2 hygromycin B-resistant mutants was resistant to the inhibition of elongation caused by hygromycin B.