Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA.
Center for RNA Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA.
Nat Commun. 2020 Nov 23;11(1):5949. doi: 10.1038/s41467-020-19775-w.
Multivalent polyions can undergo complex coacervation, producing membraneless compartments that accumulate ribozymes and enhance catalysis, and offering a mechanism for functional prebiotic compartmentalization in the origins of life. Here, we evaluate the impact of lower, more prebiotically-relevant, polyion multivalency on the functional performance of coacervates as compartments. Positively and negatively charged homopeptides with 1-100 residues and adenosine mono-, di-, and triphosphate nucleotides are used as model polyions. Polycation/polyanion pairs are tested for coacervation, and resulting membraneless compartments are analyzed for salt resistance, ability to provide a distinct internal microenvironment (apparent local pH, RNA partitioning), and effect on RNA structure formation. We find that coacervates formed by phase separation of the shorter polyions more effectively generated distinct pH microenvironments, accumulated RNA, and preserved duplexes than those formed by longer polyions. Hence, coacervates formed by reduced multivalency polyions are not only viable as functional compartments for prebiotic chemistries, they can outperform higher molecular weight analogues.
多价聚离子可以发生复杂凝聚，形成无膜隔室，从而积累核酶并增强催化作用，并为生命起源中功能性原代隔间化提供了一种机制。在这里，我们评估了较低的、更具原代相关性的聚离子多价性对凝聚作为隔间的功能性能的影响。具有 1-100 个残基的正、负电荷同聚肽和单、二、三磷酸腺苷核苷酸被用作模型聚离子。测试聚阳离子/聚阴离子对的凝聚，并分析所得无膜隔室的耐盐性、提供独特内部微环境的能力（明显的局部 pH 值、RNA 分配）以及对 RNA 结构形成的影响。我们发现，通过较短聚离子的相分离形成的凝聚体比通过较长聚离子形成的凝聚体更有效地产生了不同的 pH 微环境，积累了 RNA，并保存了双链体。因此，由降低的多价聚离子形成的凝聚体不仅可以作为原代化学的功能性隔室，而且可以胜过高分子量类似物。
