Polyethylene Glycol Impacts Conformation and Dynamics of Prolyl-tRNA Synthetase Via Crowding and Confinement Effects.

Polyethylene glycol (PEG) is a flexible, nontoxic polymer commonly used in biological and medical research, and it is generally regarded as biologically inert. PEG molecules of variable sizes are also used as crowding agents to mimic intracellular environments. A recent study with PEG crowders revealed decreased catalytic activity of prolyl-tRNA synthetase (Ec ProRS), where the smaller molecular weight PEGs had the maximum impact.