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Antimicrobial Agents
Aminoglycosides: How They Stop Bacteria
Description
Aminoglycosides are bactericidal antibiotics that stop bacteria by targeting the ribosome and disrupting protein synthesis. They are highly potent drugs made of amino-modified sugars linked by glycosidic bonds to an aminocyclitol core, such as 2-deoxystreptamine or streptamine. Their strong positive charge helps them bind ti...
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Transcript
氨基糖苷类抗生素(如链霉素)是强效的杀菌性抗生素。这类抗生素以细菌核糖体为靶点,通过多种途径干扰蛋白质合成。
链霉素通常与细菌核糖体的30S亚基结合。
这种结合会导致构象扭曲,阻止 mRNA 与起始 tRNA 的正确对齐。
这种畸变进一步阻止了功能性70S起始复合物的形成。
因此,核糖体将停留在无功能的起始前停滞状态。
链霉素还可以在延伸阶段影响核糖体,可导致核糖体对mRNA密码子的误读,并添加错误的氨基酸。
这些翻译错误会导致蛋白质错误折叠或截短 可插入细菌细胞膜,改变其通透性,导致细胞死亡。
此外,链霉素可在延伸过程中将核糖体锁定在非活性构象中。它会阻断延伸过程,并...
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