A Self-Assembled Aggregate Composed of a Fatty Acid Membrane and the Building Blocks of Biological Polymers Provides a First Step in the Emergence of Protocells.-猫眼课题宝

DOI：

10.3390/life6030033

发表时间：

2016-08-11

期刊：

Life (Basel, Switzerland)

影响因子：

通讯作者：

中科院分区：

其他

文献类型：

作者：

Black RA;Blosser MC

来源链接：

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5041009/?report=classic

我们认为，地球上细胞生命起源的第一步是脂肪酸与RNA和蛋白质的构建块的自组装，从而产生稳定的聚集体。这一方案解释了细胞中益生菌成分的选择和浓缩；早期膜的稳定和生长；生物聚合物合成的催化；以及膜、RNA和蛋白质的共存。在这篇文章中，我们回顾了所提出的聚集体形成的证据和原理：(I)公认的脂肪酸自组装形成小泡的现象；(Ii)我们已发表的证据表明，核苷酸和糖结合并稳定这些小泡；以及(Iii)氨基酸可能也这样做的原因。然后我们解释了构象限制和化学环境的改变是如何促进核苷、寡核苷酸和多肽的形成的。最后，我们讨论了产生的低聚物，即使是短的和随机的，如何比它们的构建块更多地增加囊泡的稳定性和生长，以及这些囊泡之间的竞争如何导致具有复杂功能的更长的聚合物。

We propose that the first step in the origin of cellular life on Earth was the self-assembly of fatty acids with the building blocks of RNA and protein, resulting in a stable aggregate. This scheme provides explanations for the selection and concentration of the prebiotic components of cells; the stabilization and growth of early membranes; the catalysis of biopolymer synthesis; and the co-localization of membranes, RNA and protein. In this article, we review the evidence and rationale for the formation of the proposed aggregate: (i) the well-established phenomenon of self-assembly of fatty acids to form vesicles; (ii) our published evidence that nucleobases and sugars bind to and stabilize such vesicles; and (iii) the reasons why amino acids likely do so as well. We then explain how the conformational constraints and altered chemical environment due to binding of the components to the membrane could facilitate the formation of nucleosides, oligonucleotides and peptides. We conclude by discussing how the resulting oligomers, even if short and random, could have increased vesicle stability and growth more than their building blocks did, and how competition among these vesicles could have led to longer polymers with complex functions.