Glycine to Oligoglycine via Sequential Trimetaphosphate Activation Steps in Drying Environments.
Glycine to Oligoglycine via Sequential Trimetaphosphate Activation Steps in Drying Environments.
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DOI：
10.1007/s11084-022-09634-7
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发表时间：
2022-12
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影响因子：
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通讯作者：
Hayley A Boigenzahn;J. Yin
中科院分区：
文献类型：
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作者：
Hayley A Boigenzahn;J. Yin
多磷酸介导的肽键形成是现代生物体中蛋白质合成的核心，但一种更简单的激活形式可能早于蛋白质和RNA的出现。一种建议的方案涉及三偏磷酸盐（TP），一种促进肽缩合的无机磷酸盐。高pH值和干燥也可以促进肽键的形成，但这些因素与TP的相互作用还有待于动力学表征。我们研究了在干燥过程中在TP存在下在初始碱性条件下形成的甘氨酸低聚物的形成。通过官能化和具有紫外吸收的高效液相色谱法（UV-HPLC）分析了在24小时内取样的寡肽产物。当它们干燥时，两种不同的pH依赖机制在该过程的不同阶段占主导地位。第一种机制发生在碱性溶液中，并激活单体氨基酸形成二聚体，同时降低pH值。我们的结果，然后成为一致的第二种机制，在中性pH值和消耗二聚体，形成较长的产品。一系列反应可能发生的可能性，其中第一个反应改变了环境，有利于第二个，等等，可能对益生元聚合有更广泛的影响。研究环境在时变条件下如何变化，如干燥，可以帮助我们了解有机聚合物在生命起源期间如何形成。
Polyphosphate-mediated peptide bond formation is central to protein synthesis in modern organisms, but a simpler form of activation likely preceded the emergence of proteins and RNA. One suggested scenario involves trimetaphosphate (TP), an inorganic phosphate that promotes peptide condensation. Peptide bond formation can also be promoted by high pH and drying, but the interaction of these factors with TP has yet to be characterized kinetically. We studied the formation of glycine oligomers formed under initially alkaline conditions in the presence of TP during the process of drying. Oligopeptide products sampled over 24 h were analyzed by functionalization and high-performance liquid chromatography with ultraviolet absorption (UV-HPLC). As they dried, two different pH-dependent mechanisms dominated during different stages of the process. The first mechanism occurs in alkaline solutions and activates monomer amino acids to form dimers while reducing the pH. Our results then become consistent with a second mechanism that proceeds at neutral pH and consumes dimers to form longer products. The possibility that a series of reactions might occur where the first reaction changes the environment to favor the second, and so on, may have broader implications for prebiotic polymerization. Studying how the environment changes during time-varying conditions, like drying, could help us understand how organic polymers formed during the origin of life.