Department of Agrobiology and Agrochemistry, University of Tuscia, Viterbo, Italy.
Orig Life Evol Biosph. 2011 Oct;41(5):437-51. doi: 10.1007/s11084-011-9239-0. Epub 2011 Apr 12.
Mineral components of the Murchison meteorite were investigated in terms of potential catalytic effects on synthetic and hydrolytic reactions related to ribonucleic acid. We found that the mineral surfaces catalyzed condensation reactions of formamide to form carboxylic acids, amino acids, nucleobases and sugar precursors. These results suggest that formamide condensation reactions in the parent bodies of carbonaceous meteorites could give rise to multiple organic compounds thought to be required for the emergence of life. Previous studies have demonstrated similar catalytic effects for mineral assemblies likely to have been present in the early Earth environment. The minerals had little or no effect in promoting hydrolysis of RNA (24mer of polyadenylic acid) at 80°C over a pH range from 4.2 to 9.3. RNA was most stable in the neutral pH range, with a half-life ~5 h, but at higher and lower pH ranges the half-life decreased to ~1 h. These results suggest that if RNA was somehow incorporated into a primitive form of RNA-based thermophilic life, either it must be protected from random hydrolytic events, or the rate of synthesis must exceed the rate of hydrolysis.
我们研究了默奇森陨石中的矿物质成分，探讨它们对与核糖核酸有关的合成和水解反应的潜在催化作用。我们发现，矿物质表面能促进甲酰胺缩合反应，生成羧酸、氨基酸、核苷碱基和糖前体。这些结果表明，在碳质陨石的母体中，甲酰胺缩合反应可能会产生多种被认为是生命出现所必需的有机化合物。先前的研究表明，在早期地球环境中可能存在的矿物质组合具有类似的催化作用。在 pH 值范围为 4.2 至 9.3 的条件下，这些矿物质对 RNA（多聚腺嘌呤酸 24 聚体）的水解作用影响很小或没有。RNA 在中性 pH 值范围内最稳定，半衰期约为 5 小时，但在较高和较低的 pH 值范围内，半衰期缩短至约 1 小时。这些结果表明，如果 RNA 以某种方式被整合到原始的基于 RNA 的嗜热生命形式中，那么它必须受到保护，以免受到随机水解事件的影响，或者合成的速度必须超过水解的速度。
