文章基本信息

标题：Abiotic production of sugar phosphates and uridine ribonucleoside in aqueous microdroplets
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作者：Inho Nam ; Jae Kyoo Lee ; Hong Gil Nam 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2017
卷号：114
期号：47
页码：12396-12400
DOI：10.1073/pnas.1714896114
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Phosphorylation is an essential chemical reaction for life. This reaction generates fundamental cell components, including building blocks for RNA and DNA, phospholipids for cell walls, and adenosine triphosphate (ATP) for energy storage. However, phosphorylation reactions are thermodynamically unfavorable in solution. Consequently, a long-standing question in prebiotic chemistry is how abiotic phosphorylation occurs in biological compounds. We find that the phosphorylation of various sugars to form sugar-1-phosphates can proceed spontaneously in aqueous microdroplets containing a simple mixture of sugars and phosphoric acid. The yield for d -ribose-1-phosphate reached over 6% at room temperature, giving a Δ G value of −1.1 kcal/mol, much lower than the +5.4 kcal/mol for the reaction in bulk solution. The temperature dependence of the product yield for the phosphorylation in microdroplets revealed a negative enthalpy change (Δ H = −0.9 kcal/mol) and a negligible change of entropy (Δ S = 0.0007 kcal/mol·K). Thus, the spontaneous phosphorylation reaction in microdroplets occurred by overcoming the entropic hurdle of the reaction encountered in bulk solution. Moreover, uridine, a pyrimidine ribonucleoside, is generated in aqueous microdroplets containing d -ribose, phosphoric acid, and uracil, which suggests the possibility that microdroplets could serve as a prebiotic synthetic pathway for ribonucleosides.
关键词：sugar phosphorylation ; uracil ribosylation ; microdroplet chemistry ; prebiotic chemistry ; origin of life