Howard Hughes Medical Institute, Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital , 185 Cambridge Street, Boston, Massachusetts 02114, United States.
Department of Genetics, Harvard Medical School , 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States.
J Am Chem Soc. 2016 Dec 28;138(51):16669-16676. doi: 10.1021/jacs.6b08801. Epub 2016 Dec 13.
Early protocells are likely to have arisen from the self-assembly of RNA, peptide, and lipid molecules that were generated and concentrated within geologically favorable environments on the early Earth. The reactivity of these components in a prebiotic environment that supplied sources of chemical energy could have produced additional species with properties favorable to the emergence of protocells. The geochemically plausible activation of amino acids by carbonyl sulfide has been shown to generate short peptides via the formation of cyclic amino acid N-carboxyanhydrides (NCAs). Here, we show that the polymerization of valine-NCA in the presence of fatty acids yields acylated amino acids and peptides via a mixed anhydride intermediate. Notably, N-oleoylarginine, a product of the reaction between arginine and oleic acid in the presence of valine-NCA, partitions spontaneously into vesicle membranes and mediates the association of RNA with the vesicles. Our results suggest a potential mechanism by which activated amino acids could diversify the chemical functionality of fatty acid membranes and colocalize RNA with vesicles during the formation of early protocells.
早期原细胞可能是由 RNA、肽和脂质分子自组装而成的，这些分子在早期地球上地质条件有利的环境中生成并浓缩。在提供化学能源来源的前生物环境中，这些成分的反应性可能会产生具有有利于原细胞出现的特性的其他物质。已经证明，通过形成环状氨基酸 N-羧酸酐（NCAs），羰基硫对氨基酸的地球化学上合理的激活可以生成短肽。在这里，我们表明，在脂肪酸存在下，缬氨酸-NCA 的聚合通过混合酸酐中间体生成酰化氨基酸和肽。值得注意的是，N-油酰精氨酸是精氨酸与油酸在缬氨酸-NCA 存在下反应的产物，它自发地分配到囊泡膜中，并介导 RNA 与囊泡的结合。我们的结果表明，一种潜在的机制，即通过激活的氨基酸可以使脂肪酸膜的化学功能多样化，并在前原细胞形成过程中使 RNA 与囊泡共定位。
