Chymotrypsin Activity in Peptide-Based Coacervates

Presenter: Adhithi Varadarajan

Faculty Sponsor: Sarah L. Perry

School: UMass Amherst

Research Area: Chemical and Biomolecular Engineering

Session: Poster Session 5, 3:15 PM - 4:00 PM, 165, D1

ABSTRACT

Bioremediation using enzymes offers a sustainable approach to mitigate pesticide and other chemical contamination in soils, but enzyme instability in aqueous environments limits practical applications. Encapsulation within complex coacervates offers a solution. Complex coacervates are liquid-liquid phase separated droplets formed by oppositely charged polymers, creating a protective environment that enhances enzyme stability and activity. This study investigates how the sequence and hydrophobicity of peptide-based coacervates influence the encapsulation and enzymatic activity of alpha-chymotrypsin (ChT). Using a series of designed polypeptides with varying charge block sizes and hydrophobic character, we quantify ChT partitioning between coacervate and supernatant phases via the Bradford assay. The charge fraction of cationic peptides is systematically varied from 0.1 to 0.9 to identify conditions maximizing protein encapsulation. Enzyme activity is assessed using a fluorogenic substrate, comparing free enzyme, supernatant, and coacervate-encapsulated populations. Previous work has shown that charge clustering on proteins like ChT enhances encapsulation compared to proteins with more isotropic charge distributions. Therefore, we hypothesize that peptide sequence and hydrophobicity modulate both the extent of ChT partitioning and its subsequent catalytic behavior. Early findings indicate that encapsulation efficiency is dependent on the specific pairing of polypeptide sequences, with some combinations outperforming others. Understanding these design rules for protein encapsulation will enable the development of coacervate systems for applications in environmental remediation, sustainable agriculture, and therapeutic delivery.

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