Catalytic activity of water molecules in gas‐phase glycine dimerization
Catalytic activity of water molecules in gas‐phase glycine dimerization
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DOI：
10.1002/qua.26469
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发表时间：
2020-10
影响因子：
2.2
通讯作者：
Ariel Gale;T. Odbadrakh;G. Shields
中科院分区：
文献类型：
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作者：
Ariel Gale;T. Odbadrakh;G. Shields
甘氨酸的二聚反应是氨基酸最简单的寡聚反应，在生物学中起着重要的作用。虽然该反应在水相中在化学上是不利的，但它已被证明在气相中是自发的，并通过两种不同的协同反应机理进行，称为顺式和反式。这可能对生命前化学产生深远的影响，因为普通的大气成核前簇被认为参与了早期地球大气中的气相反应。我们假设，在这些集群中的水分子的特定安排可能会导致降低氨基酸二聚化的反应障碍，并可能导致非生物催化多肽。我们使用基于遗传算法的构型采样、密度泛函理论几何和基于域的局部对自然轨道耦合簇电子结构相结合的方法，在一个由一到五个水分子溶剂化的甘氨酸二聚化的转变态系统上测试我们的假设。首先，我们讨论了模型化学用于获得我们的结果的有效性。然后，我们表明，certedcis机制的吉布斯自由能垒确实可以降低通过添加多达5个水分子，这取决于温度。
The dimerization of glycine is the simplest oligomerization of amino acids and plays an important role in biology. Although this reaction is thermodynamically unfavorable in the aqueous phase, it has been shown to be spontaneous in the gas phase and proceeds via two different concerted reaction mechanisms known ascisandtrans. This may have profound implications in prebiotic chemistry as common atmospheric prenucleation clusters are thought to have participated in gas‐phase reactions in the early Earth's atmosphere. We hypothesize that particular arrangements of water molecules in these clusters could lead to lowering of the reaction barrier of amino acid dimerization and could lead to abiotic catalysis toward polypeptides. We test our hypothesis on a system of thecistransition state of glycine dimerization solvated by one to five water molecules using a combination of a genetic algorithm‐based configurational sampling, density functional theory geometries, and domain‐based local pair natural orbital coupled‐cluster electronic structure. First, we discuss the validity of the model chemistries used to obtain our results. Then, we show that the Gibbs free energy barrier for the concertedcismechanism can indeed be lowered by the addition of up to five water molecules, depending on the temperature.