posted on 2024-01-08, 09:04authored byAlexander B Cook, Bruno Delgado Gonzalez, Jan C M van Hest
Complex coacervates
are a versatile platform to mimic the structure
of living cells. In both living systems and artificial cells, a macromolecularly
crowded condensate phase has been shown to be able to modulate enzyme
activity. Yet, how enzyme activity is affected by interactions (particularly
with cationic charges) inside coacervates is not well studied. Here,
we synthesized a series of amino-functional polymers to investigate
the effect of the type of amine and charge density on coacervate formation,
stability, protein partitioning, and enzyme function. The polymers
were prepared by RAFT polymerization using as monomers aminoethyl
methacrylate (AEAM), 2-(dimethylamino)ethyl methacrylate (DMAEMA),
imidazolepropyl methacrylamide (IPMAm), and [2-(methacryloyloxy)ethyl]
trimethylammonium chloride (TMAEMA). Membranized complex coacervate
artificial cells were formed with these polycations and an anionic
amylose derivative. Results show that polycations with reduced charge
density result in higher protein mobility in the condensates and also
higher enzyme activity. Insights described here could help guide the
use of coacervate artificial cells in applications such as sensing,
catalysis, and therapeutic formulations.