论文标题
液 - 液相分离作为复杂共培养的第二步
Liquid-liquid Phase Separation as the Second Step of Complex Coacervation
论文作者
论文摘要
酪氨酸和精氨酸残基之间的pi-cation键介导的液态液相分离（LLP）具有生物学重要性。为了了解与复杂共凝蛋白的凝聚相中蛋白质之间的相互作用，我们在含有酪氨酸（PY）和精氨酸（PR）的低聚物（PR）之间进行多个伞状计算。我们发现PR-PY络合能力驱动。元动力学模拟表明，这种络合能的能量主要来自Pi-cation键。在复杂共凝聚的第二个结合步骤中运行自由能计算时，我们发现该过程与PI介导的LLP之间的相似之处。这些计算使我们相信，与常见的概念相反，涉及熵络合的整体复杂共凝聚，然后是含有精氨酸和酪氨酸残基的蛋白质引用的。相反，后一个步骤本身，中性波利离子对聚集在一起是PI-cation介导的LLP的正确机制。
Liquid liquid phase separation (LLPS) mediated by pi-cation bonds between tyrosine and arginine residues are of biological importance. To understand the interactions between proteins in the condensed phase in close analogy to complex coacervation, we run multiple umbrella calculations between oligomers containing tyrosine (pY) and arginine (pR). We find pR-pY complexation to be energetically driven. Metadynamics simulations reveal that this energy of complexation comes primarily from pi-cation bonds. On running free energy calculation for the second binding step of complex coacervation, we find striking similarities between this process and pi-mediated LLPS. These calculations lead us to believe that contrary to the common notion, complex coacervation as whole, which involves an entropic complexation followed by an energetic aggregation is not invoked by proteins containing arginine and tyrosine residues. Rather, the latter step in itself, in which neutral polyion pairs aggregate together is the correct mechanism for pi-cation mediated LLPS.
