Sedimentary Minerals, Organic Chemical Transformations, and the Origin of Life

沉积矿物、有机化学转化和生命起源

• 批准号: 2213438
• 负责人: Steven Benner
• 金额: $ 52.52万
• 依托单位: Foundation for Applied Molecular Evolution, Inc.
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-15 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2213438&HistoricalAwards=false
• 关键词: Sedimentary; Minerals; Organic; Chemical; Transformations

Our understanding of geological environments on Earth 4.35 billion years ago has advanced to the point where geology can be combined with organic chemistry that does not need careful human control to build models for how the first genetic molecules might have emerged on Earth, and possibly on other rocky planets like Mars. This "hands off" chemistry can be further simplified in the context of rocks present in those environments. This combination now allows us to advance scientific knowledge relevant to one of the oldest questions posed by humankind: Where did we come from? Further, the simplicity of the prebiotic chemistry that this project will develop makes it accessible to students, even those in high school. In addition to advancing the science, this project will deliver kits to those students that will let them participate in the current excitement in geochemistry relevant to this "big question".This geology-chemistry combination supports the "RNA first hypothesis" for the origin of life, which holds that Darwinian evolution emerged based on the abiological formation of ribonucleic acid that served as its first informational molecule. Here, the geological environment comprises intermittently dry, constrained aquifers that receive by rain small carbohydrates stabilized by volcanic sulfur dioxide, reduced nitrogen-containing organic molecules, and other species that were created by UV and electrical discharge in atmospheres that had been reduced by iron fragmented from the cores of impacting bodies. The geological environment includes surrounding rocks from a redox neutral crust, including borate evaporite minerals, as well as basaltic glass generated by the impacts and volcanism on the young Earth. The basaltic glass contains dehydrated phosphates which can serve as a catalyst to assemble RNA. In this single environment, small organics can yield oligomeric RNA 100-200 nucleotides long by a process that initiates with borate-controlled maturation of stabilized carbohydrates, phosphorylation by glass-delivered polyphosphates, reaction of ribose cyclic phosphates with nucleobases to give nucleotides, with borate-moderated phosphorylation yielding nucleoside triphosphates. This project will complete structure analysis of RNA products formed from triphosphates by impact glass, integrate carbohydrate processing with downstream nucleoside synthesis, explore the possibility of this environment producing homochiral products, and develop the sedimentary and igneous geology of relevant minerals for students to work with.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

我们对43.5亿年前地球地质环境的了解已经发展到这样的程度：地质学可以与有机化学相结合，不需要人为的仔细控制，就可以建立模型，说明第一批遗传分子是如何在地球上出现的，也可能在火星等其他岩石行星上出现的。在这些环境中存在的岩石的背景下，这种“不受控制”的化学反应可以进一步简化。这种结合现在使我们能够推进与人类提出的最古老问题之一相关的科学知识：我们从哪里来？此外，这个项目将开发的益生元化学的简单性使学生，甚至高中生都能接触到它。除了推动科学发展，该项目还将向那些学生提供工具包，让他们参与到与这个“大问题”相关的地球化学领域的当前兴奋中来。这种地质化学结合支持了生命起源的“RNA第一假说”，该假说认为，达尔文的进化是基于核糖核酸的非生物形成而出现的，核糖核酸是生命的第一个信息分子。在这里，地质环境包括间歇性干燥、受限制的含水层，这些含水层通过雨水接收由火山二氧化硫稳定的小碳水化合物、减少的含氮有机分子和其他物种，这些物种是由大气中的紫外线和放电产生的，这些物质是由撞击体核心的铁碎片还原的。地质环境包括来自氧化还原中性地壳的围岩，包括硼酸盐蒸发岩矿物，以及由年轻地球上的撞击和火山作用产生的玄武岩玻璃。玄武岩玻璃含有脱水磷酸盐，可作为聚合RNA的催化剂。在这种单一的环境中，小有机物可以产生100-200个核苷酸长的寡聚RNA，其过程开始于硼酸控制的稳定碳水化合物的成熟，玻璃传递的多磷酸盐的磷酸化，核糖环磷酸与核碱基反应产生核苷酸，硼酸调节的磷酸化产生三磷酸核苷。本项目将完成冲击玻璃对三磷酸盐形成的RNA产物的结构分析，将碳水化合物加工与下游核苷合成结合起来，探索这种环境产生同手性产物的可能性，并为学生开展相关矿物的沉积和火成岩地质研究。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。