Self-assembly processes in the prebiotic environment
Self-assembly processes in the prebiotic environment
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DOI：
10.1098/rstb.2006.1905
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发表时间：
2006-10-29
影响因子：
6.3
通讯作者：
Guggenheim, Stephen
中科院分区：
文献类型：
--
作者：
Deamer, David;Singaram, Sara;Guggenheim, Stephen
指导生命起源研究的一个重要问题涉及具有生命性质的分子系统在早期地球上首次出现的环境条件。一个合适的地点需要液态水、有机化合物的来源、驱动聚合反应的能量来源，以及一个使化合物足够浓缩以进行物理和化学相互作用的过程。一个这样的地点是地热环境，其中有机化合物与矿物表面相互作用，促进自组装和聚合反应。在这里，我们报告了对两个地热地点的初步研究，在那里，代表性有机溶质（氨基酸、核碱基、脂肪酸和甘油）和磷酸盐的混合物与粘土衬里池中的高温水混合。大多数添加的有机物和磷酸盐被从溶液中去除，在几分钟到几小时内测量了一半的时间。对粘土（主要是蒙脱石和高岭土）的分析表明，在酸性pH池中，有机物被吸附在矿物表面，但随后可能在碱性溶液中释放出来。这些结果有助于限制生命起源的可能环境范围。有利于有机溶质自组装的位置是离子溶质含量相对较低的水环境，在中等温度范围和中性pH范围内，溶质的循环浓度可以通过短暂的干燥间隔发生。
An important question guiding research on the origin of life concerns the environmental conditions where molecular systems with the properties of life first appeared on the early Earth. An appropriate site would require liquid water, a source of organic compounds, a source of energy to drive polymerization reactions and a process by which the compounds were sufficiently concentrated to undergo physical and chemical interactions. One such site is a geothermal setting, in which organic compounds interact with mineral surfaces to promote self-assembly and polymerization reactions. Here, we report an initial study of two geothermal sites where mixtures of representative organic solutes (amino acids, nucleobases, a fatty acid and glycerol) and phosphate were mixed with high-temperature water in clay-lined pools. Most of the added organics and phosphate were removed from solution with half-times measured in minutes to a few hours. Analysis of the clay, primarily smectite and kaolin, showed that the organics were adsorbed to the mineral surfaces at the acidic pH of the pools, but could subsequently be released in basic solutions. These results help to constrain the range of possible environments for the origin of life. A site conducive to self-assembly of organic solutes would be an aqueous environment relatively low in ionic solutes, at an intermediate temperature range and neutral pH ranges, in which cyclic concentration of the solutes can occur by transient dry intervals.