NSF-NASA Center for Chemical Evolution, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Nat Commun. 2022 May 11;13(1):2569. doi: 10.1038/s41467-022-30191-0.
It is widely assumed that the condensation of building blocks into oligomers and polymers was important in the origins of life. High activation energies, unfavorable thermodynamics and side reactions are bottlenecks for abiotic peptide formation. All abiotic reactions reported thus far for peptide bond formation via thioester intermediates have relied on high energy molecules, which usually suffer from short half-life in aqueous conditions and therefore require constant replenishment. Here we report plausible prebiotic reactions of mercaptoacids with amino acids that result in the formation of thiodepsipeptides, which contain both peptide and thioester bonds. Thiodepsipeptide formation was achieved under a wide range of pH and temperature by simply drying and heating mercaptoacids with amino acids. Our results offer a robust one-pot prebiotically-plausible pathway for proto-peptide formation. These results support the hypothesis that thiodepsipeptides and thiol-terminated peptides formed readily on prebiotic Earth and were possible contributors to early chemical evolution.
人们普遍认为，将构建块凝聚成低聚物和聚合物对于生命的起源很重要。高活化能、不利的热力学和副反应是无生命肽形成的瓶颈。迄今为止，所有通过硫酯中间体形成肽键的非生物反应都依赖于高能分子，这些分子通常在水相条件下半衰期较短，因此需要不断补充。在这里，我们报告了巯基酸与氨基酸的合理的前生物反应，这些反应导致硫代二肽的形成，其中包含肽键和硫酯键。通过简单地干燥和加热巯基酸与氨基酸，在很宽的 pH 和温度范围内实现了硫代二肽的形成。我们的结果提供了一种强大的、一锅式的、前生物上合理的原肽形成途径。这些结果支持了这样的假设，即在原始地球上硫代二肽和硫醇末端肽很容易形成，并且可能是早期化学进化的贡献者。
