Charge-Mediated Interactions Affect Enzymatic Reactions in Peptide Condensates
Ayala Lampel, PhD
Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel. Center for Nanoscience and Nanotechnology Tel Aviv University, Tel Aviv, 69978, Israel Sagol Center for Regenerative Biotechnology Tel Aviv University, Tel Aviv, 69978, Israel Center for the Physics and Chemistry of Living Systems Tel Aviv University, Tel Aviv, 69978, Israel
Abstract- Biomolecular condensates, formed through liquid-liquid phase separation (LLPS), act as enzymatic reaction centers in cells by increasing the local concentrations of enzymes and substrates, thus facilitating reaction kinetics and regulatory mechanisms. Inspired by these natural systems, synthetic condensates are increasingly being developed for diverse applications, including payload delivery, sensing, and as microreactors where enzymatic reaction kinetics can be modulated by factors such as pH, viscosity, and enzyme-substrate co-localization. We investigated how the physicochemical properties of enzymes and substrates influence condensate formation and their function as microreactors. For this, we employed a minimalistic complex coacervation system of oppositely charged LLPS-promoting peptides, and focused on two simple enzymatic model systems, cellulase and alkaline phosphatase, which differ in molecular weight and isoelectric point. Our findings demonstrate how electrostatic forces within condensates influence their role as microreactors. Specifically, the ability of condensates to encapsulate or exclude phosphatase, cellulase, and their substrates—which is pivotal for the regulation of reaction kinetics—is determined by enzyme surface charge, substrate charge, and condensate charge stoichiometry. These results highlight the potential of utilizing electrostatic forces within condensates to modulate enzymatic reactions, providing critical insights for the development of synthetic condensates as microreactors in biotechnology and materials science.
BIO– Ayala Lampel is an assistant professor (senior lecturer) at Tel Aviv University. She obtained a BSc in Neuroscience and a PhD in Biotechnology at Tel Aviv University, where she worked on virus protein self-assembly in the group of Prof. Ehud Gazit. Ayala performed her postdoctoral research in the group of Prof. Rein Ulijn at the Advanced Science Research Center (ASCR) of the City University of New York (CUNY) between 2015-2019, where she developed bioinspired peptide-based materials. In 2019, she started her independent research group at Tel Aviv University. Her group develops synthetic cells and biomolecular condensates.