Understanding enzyme kinetics on coacervate as a substrate hub

There remains a gap in understanding the enzyme interactions with the coacervate as a substrate hub. Here, we study how the hydrophobicity nature of coacervate affects the interactions of the embedded substrate with a protease. We design oligopeptide-based coacervates that comprise an anionic Asp-peptide (D₁₀) and a cationic Arg-peptide (R₅R₅) with a proteolytic cleavage site. The coacervates dissolve when exposed to the main protease. We exploit the condensed structure, implement a self-quenching mechanism, and characterize enzyme kinetics with Cy5.5-labeled peptides. The determined specificity constant is 5,817 M⁻¹ s⁻¹ and is similar to that of the free substrate. We further show that the enzyme kinetics depend on the amount of dye incorporated into the coacervates. Our work presents a simple design for coacervates with tuned bioactivities and provides insights into the kinetics between the enzyme and coacervates as a substrate hub.