RUI: Synthesis of Sulfur Containing Amino Acids in Astrophysical Ices

化学系的化学结构、动力学和机制（CSDM-A）项目将资助加州州立大学北岭分校的西蒙·加勒特教授，研究氨基酸是如何在外星非生物环境中由小分子形成的。他们正试图在实验室里通过对含有合适来源的天体物理冰类似物的辐射分解来合成氨基酸。这项工作将通过一系列适合本科生的相互关联的短期实验进行，为他们提供一种刺激的体验，从而鼓励他们攻读STEM领域的高级学位。研究生命是如何在地球上开始的，以及它是否在其他地方进化的问题，可以引起公众和广大科学界的极大兴趣。Garrett教授和他的研究小组正在对水、乙腈、H2S或OCS的冰冷混合物进行实验，这些混合物在真空中沉积，用电子和He+照射，并用质谱、红外光谱、x射线光电子能谱和液相色谱进行探测。该项目的一个中心目标是通过向冰中添加相关的硫源，率先生产出含硫氨基酸，特别是半胱氨酸和蛋氨酸。尽管天体物理冰类似物的实验室实验已经成功地产生了各种氨基酸前体，但含硫的半胱氨酸和蛋氨酸还没有被制造出来，尽管它们在蛋白质功能和折叠中很重要。这项工作的另一个目标是通过形成强酸硫酸来开拓原位水解，因为已知冰中辐照残留物的酸水解是产生氨基酸所必需的。

With this award, the Chemical Structure, Dynamics and Mechanisms (CSDM-A) Program of the Division of Chemistry is funding Professor Simon Garrett of California State University-Northridge to investigate how amino acids can be formed from small molecules in extraterrestrial abiotic environments. They are attempting to synthesize amino acids in the laboratory by the radiolysis of astrophysical ice analogs containing suitable sources. The work is to proceed through a series of linked, short-term, experiments suitable for undergraduate students, providing them with a stimulating experience that will encourage enrollment in advanced degrees in STEM fields. Research that addresses the question of how life began on Earth and if it has evolved elsewhere can generate significant interest from the general public and the broad scientific community. Professor Garrett and his research group are conducting experiments on icy mixtures of H2O, acetonitrile and either H2S or OCS deposited in vacuum, irradiated by electrons and He+, and probed by mass spectrometry, infrared spectroscopy, x-ray photoelectron spectroscopy and liquid chromatography. A central goal of this project is to be the first to produce sulfur-containing amino acids, notably cysteine and methionine, by adding a relevant sulfur source to the ices. Although laboratory experiments in astrophysical ice analogs have successfully generated a variety of amino acid precursors to date, sulfur containing cysteine and methionine have not been made, despite their importance in protein function and folding. An additional goal of this work is to pioneer in situ hydrolysis through the formation of a strong acid, sulfuric acid, since acid hydrolysis of irradiation residues in the ice is known to be necessary in producing amino acids.