北京大学梁德海团队报道了由从头设计的多肽和寡核苷酸形成的多电解质复合物和凝聚体。相关研究成果于2024年3月4日发表在《中国高分子科学杂志》。

活细胞中生物聚合物的液-液相分离包含多种相互作用，并发生在动态环境中。解决监管机制仍然是一个挑战。

该文中，研究人员设计了一系列肽（XXLY）6SSSGSS，并研究了它们与单链寡核苷酸的络合和凝聚行为。“X”和“Y”是可变的，以结合已知量的带电和非带电氨基酸，以及引入次级结构和pH响应性。

结果表明，静电相互作用，即电荷密度，控制着络合强度和链弛豫程度，从而决定了凝聚层的生长和尺寸。当电荷被中和时，疏水相互作用是显著的。有趣的是，肽的次级结构对相的形态表现出深刻的影响，例如固相到液相的转变。

该研究深入了解了生理条件下的相分离，有助于创造具有所需结构和功能的凝聚体。

附：原文原文

Title: Polyelectrolyte Complexes and Coacervates Formed by De novo-Designed Peptides and Oligonucleotide

Author: Tian-Hao Ren, De-Hai Liang

Issue&Volume: 2024-03-04

Abstract: The liquid-liquid phase separation of biopolymers in living cells contains multiple interactions and occurs in a dynamic environment. Resolving the regulation mechanism is still a challenge. In this work, we designed a series of peptides (XXLY)6SSSGSS and studied their complexation and coacervation behavior with single-stranded oligonucleotides. The “X” and “Y” are varied to combine known amounts of charged and non-charged amino acids, together with the introduction of secondary structures and pH responsiveness. Results show that the electrostatic interaction, which is described as charge density, controls both the strength of complexation and the degree of chain relaxation, and thus determines the growth and size of the coacervates. The hydrophobic interaction is prominent when the charges are neutralized. Interestingly, the secondary structures of peptides exhibit profound effect on the morphology of the phases, such as solid phase to liquid phase transition. Our study gains insight into the phase separation under physiological conditions. It is also helpful to create coacervates with desirable structures and functions.

DOI: 10.1007/s10118-024-3096-6

Source: https://www.cjps.org/en/article/doi/10.1007/s10118-024-3096-6/