Studies toward the unique pederin family member psymberin: structure-activity relationships, biochemical studies, and genetics identify the mode-of-action of psymberin.
Studies toward the unique pederin family member psymberin: structure-activity relationships, biochemical studies, and genetics identify the mode-of-action of psymberin.
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对独特的 pederin 家族成员 psymberin 的研究：结构-活性关系、生化研究和遗传学确定了 psymberin 的作用模式。
DOI：
10.1021/ja3057002
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发表时间：
2012
影响因子：
15
通讯作者：
Roth,MichaelG
中科院分区：
文献类型：
--
作者：
Wu,Cheng-Yang;Feng,Yu;Cardenas,EduardoR;Williams,Noelle;Floreancig,PaulE;DeBrabander,JefK;Roth,MichaelG
Psymberin是Pederin天然产品家族中唯一含有二氢异香豆素侧链的成员。Psymberin的结构修饰解偶联抑制蛋白质翻译的细胞毒性，提示psymberin具有不止一种生物活性。为了确定psymberin的分子靶标(S)，对秀丽隐杆线虫进行了正向遗传筛选。分离出多个独立的psymberin抗性突变体，每个突变体在编码核糖体蛋白的基因中包含相同的点突变。然而，携带该突变的psymberin抗性突变株对Pederin家族成员mycalamine A没有交叉抗药性，该成员与同一蛋白质的古老形式结合。因此，两个Pederin家族成员可能在如何结合相同的分子靶点方面存在差异。Psymberin在细胞中的积累对C4或C8的酰胺侧链的立体化学和二氢异香豆素侧链的存在很敏感。观察到psymberin非对映异构体或二氢异香豆素截短的类似物失去了所有的细胞毒活性，同时保留了在无细胞体外试验中抑制蛋白质翻译的能力，这可以在这些不同的细胞摄取问题的背景下解释。最后，我们还证明了与Pederin和该家族其他成员相关的起泡活性并不是由于它们的蛋白质合成抑制活性。与儿茶素和杨梅酰胺不同，psymberin不表现出刺激性或起泡活性。
Psymberin is the only member of the pederin natural product family that contains a dihydroisocoumarin side chain. Structural modifications of psymberin uncoupled inhibition of protein translation from cytotoxicity, suggesting that psymberin has more than one bioactivity. A forward genetic screen in Caenorhabditis elegans was conducted to identify the molecular target(s) of psymberin. Multiple independent psymberin-resistant mutants were isolated, each containing the same point mutation in a gene encoding a ribosomal protein. However, a psymberin-resistant mutant strain bearing this mutation was not cross-resistant to the pederin family member mycalamide A, which binds to the archaeal form of the same protein. Thus, two pederin family members likely differ in how they bind the same molecular target. The accumulation of psymberin in cells was sensitive to the stereochemistry of the amide side chain at C4 or C8 and the presence of the dihydroisocoumarin side chain. The observation that psymberin diastereomers or dihydroisocoumarin-truncated analogs lose all cytotoxic activity while retaining the ability to inhibit protein translation in a cell-free in vitro assay can be explained in the context of these differential cell uptake issues. Finally, we also demonstrate that the blistering activity associated with pederin and other members of the family is not due to their protein synthesis inhibiting activity. Unlike pederin and mycalamide, psymberin does not display irritant or blistering activity.