Chain-length heterogeneity allows for the assembly of fatty acid vesicles in dilute solutions.
Chain-length heterogeneity allows for the assembly of fatty acid vesicles in dilute solutions.
复制标题
链长异质性允许脂肪酸囊泡在稀溶液中组装。
DOI：
10.1016/j.bpj.2014.07.067
复制
发表时间：
2014-10-07
影响因子：
3.4
通讯作者：
Szostak, Jack W.
中科院分区：
文献类型：
--
作者：
Budin, Itay;Prwyes, Noam;Zhang, Na;Szostak, Jack W.
对分子构建块的浓缩和化学均匀池的要求将严重限制生命起源的合理方案。在膜自组装的情况下，益生元脂质合成的模型主要产生短的单链两亲物，其只能在非常高的浓度下形成双层囊泡。这些高临界聚集浓度（cacs）对单链脂质膜的自组装构成了重大障碍。在这里，我们研究膜的自组装在混合物中的脂肪酸具有不同的链长，任何非生物脂质合成的预期功能。我们推导出理论预测的混合物的cac通过调整热力学模型开发的类似现象的混合胶束自组装。然后，我们使用几种互补的方法来表征聚集实验，并发现CAC值与我们的理论预测密切一致。这些测量结果表明，脂肪酸混合物的cac显着降低了小部分的长链物种，从而提供了一个合理的途径为原细胞膜组装。使用基于NMR的方法来监测同位素标记的样品的聚集，我们证明了将单个组分掺入混合囊泡。这些实验表明，在稀释的混合溶液中组装的囊泡耗尽了较短链长的脂质物质，这一发现对原始细胞膜的组成有影响。
A requirement for concentrated and chemically homogeneous pools of molecular building blocks would severely restrict plausible scenarios for the origin of life. In the case of membrane self-assembly, models of prebiotic lipid synthesis yield primarily short, single-chain amphiphiles that can form bilayer vesicles only at very high concentrations. These high critical aggregation concentrations (cacs) pose significant obstacles for the self-assembly of single-chain lipid membranes. Here, we examine membrane self-assembly in mixtures of fatty acids with varying chain lengths, an expected feature of any abiotic lipid synthesis. We derive theoretical predictions for the cac of mixtures by adapting thermodynamic models developed for the analogous phenomenon of mixed micelle self-assembly. We then use several complementary methods to characterize aggregation experimentally, and find cac values in close agreement with our theoretical predictions. These measurements establish that the cac of fatty acid mixtures is dramatically lowered by minor fractions of long-chain species, thereby providing a plausible route for protocell membrane assembly. Using an NMR-based approach to monitor aggregation of isotopically labeled samples, we demonstrate the incorporation of individual components into mixed vesicles. These experiments suggest that vesicles assembled in dilute, mixed solutions are depleted of the shorter-chain-length lipid species, a finding that carries implications for the composition of primitive cell membranes.
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DOI：
10.1073/pnas.0603873103
发表时间：
2006-12-26
影响因子：
11.1
作者：
Duhr, Stefan;Braun, Dieter
通讯作者：
Braun, Dieter
DOI：
10.1073/pnas.0805086105
发表时间：
2008-09-09
影响因子：
11.1
作者：
Mansy, Sheref S.;Szostak, Jack W.
通讯作者：
Szostak, Jack W.
影响因子：
64.8
作者：
YUEN, GU;KVENVOLD.KA
通讯作者：
KVENVOLD.KA
影响因子：
15
作者：
Zhu TF;Szostak JW
通讯作者：
Szostak JW
影响因子：
15
作者：
Budin, Itay;Debnath, Anik;Szostak, Jack W.
通讯作者：
Szostak, Jack W.