Nucleobases bind to and stabilize aggregates of a prebiotic amphiphile, providing a viable mechanism for the emergence of protocells
Nucleobases bind to and stabilize aggregates of a prebiotic amphiphile, providing a viable mechanism for the emergence of protocells
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DOI：
10.1073/pnas.1300963110
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发表时间：
2013-08-13
影响因子：
11.1
通讯作者：
Keller, Sarah L.
中科院分区：
文献类型：
--
作者：
Black, Roy A.;Blosser, Matthew C.;Keller, Sarah L.
据推测，原始细胞将作为催化剂和遗传信息载体的RNA与聚集的两亲分子的封装膜结合在一起。关于这一假设的主要问题包括RNA中的四种碱基和糖是如何从益生元化合物的混合物中选择出来并与这种膜共定位的，以及膜是如何稳定的，以防止在盐水中絮凝。为了解决这些问题，我们探索了癸酸（一种益生元两亲物）聚集体与RNA中发现的碱基和糖相互作用的可能性。我们发现，这些基地，以及一些但不是所有的相关基地，结合癸酸聚集体。此外，碱和核糖都抑制盐对癸酸的絮凝作用。碱基的抑制程度与它们的结合程度相关，核糖的抑制程度大于三种类似的糖。最后，碱基和核糖的稳定作用是相加的。因此，益生元两亲物的聚集体结合某些杂环碱基和糖，包括在RNA中发现的那些，并且这种结合使聚集体对盐稳定。这些相互加强的机制可能推动了原始细胞的出现。
Primordial cells presumably combined RNAs, which functioned as catalysts and carriers of genetic information, with an encapsulating membrane of aggregated amphiphilic molecules. Major questions regarding this hypothesis include how the four bases and the sugar in RNA were selected from a mixture of prebiotic compounds and colocalized with such membranes, and how the membranes were stabilized against flocculation in salt water. To address these questions, we explored the possibility that aggregates of decanoic acid, a prebiotic amphiphile, interact with the bases and sugar found in RNA. We found that these bases, as well as some but not all related bases, bind to decanoic acid aggregates. Moreover, both the bases and ribose inhibit flocculation of decanoic acid by salt. The extent of inhibition by the bases correlates with the extent of their binding, and ribose inhibits to a greater extent than three similar sugars. Finally, the stabilizing effects of a base and ribose are additive. Thus, aggregates of a prebiotic amphiphile bind certain heterocyclic bases and sugars, including those found in RNA, and this binding stabilizes the aggregates against salt. These mutually reinforcing mechanisms might have driven the emergence of protocells.