Electrochemical Investigation of Post-Translational Modification-Modulated Biomolecular Liquid–Liquid Phase Separation

Post-translational modification (PTM) plays a key role in the regulation of liquid-liquid phase separation (LLPS), which participates in cell behaviors and pathological processes. Quantitative analysis of PTM-regulated LLPS is therefore essential for understanding cellular processes and discovering new disease targets. However, the membrane-free structure, dynamic characteristics, and distinct chemical microenvironment of biomolecular condensates pose challenges to traditional methods. In this contribution, an electrochemical method is proposed to analyze PTM-regulated LLPS for the first time by exploring its effect on electrochemical species. By taking dephosphorylation as a model, we demonstrate that the degree of LLPS initiated by dephosphorylation can be quantitatively assessed. Importantly, this label-free method does not require probe immobilization or signal tagging, making it easily extendable to various PTM-involved LLPS processes. Overall, this work provides a highly sensitive, simplified, and universal approach for the quantitative study of LLPS, with broad potential applications in physiological and pathological research studies.