Sea cucumbers produce saponins as a chemical defense mechanism, however their cells can tolerate the cytotoxic nature of these chemicals. To elucidate the molecular mechanisms behind this tolerance a suite of complementary biophysical tools was used, firstly using liposomes for in vitro techniques then using in silico approaches for a molecular-level insight. The holothuroid saponin Frondoside A, caused significantly less permeabilization in liposomes containing a Δ⁷ holothuroid sterol than those containing cholesterol and resulted in endothermic interactions versus exothermic interactions with cholesterol containing liposomes. Lipid phases simulations revealed that Frondoside A has an agglomerating effect on cholesterol domains, however, induced small irregular Δ⁷ sterol clusters. Our results suggest that the structural peculiarities of holothuroid sterols provide sea cucumbers with a mechanism to mitigate the sterol-agglomerating effect of saponins, and therefore to protect their cells from the cytotoxicity of the saponins they produce.

中文翻译：

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不同的甾醇如何促进海参皂苷耐受的质膜。


海参产生皂苷作为化学防御机制，但它们的细胞可以耐受这些化学物质的细胞毒性。为了阐明这种耐受性背后的分子机制，使用了一套互补的生物物理工具，首先使用脂质体进行体外技术，然后使用计算机方法进行分子水平的洞察。海参皂苷 Frondoside A 在含有 Δ ⁷海参甾醇的脂质体中引起的透化作用明显低于含有胆固醇的脂质体，并导致与含有胆固醇的脂质体的吸热相互作用与放热相互作用。脂相模拟表明，Frondoside A 对胆固醇结构域具有聚集作用，但会诱导小的不规则 Δ ⁷甾醇簇。我们的研究结果表明，海参甾醇的结构特点为海参提供了一种减轻皂苷甾醇凝聚作用的机制，从而保护其细胞免受其产生的皂苷的细胞毒性。