Aggregation of an FG nucleoporin under crowded conditions

Macromolecular crowding can affect the aggregation behavior of intrinsically disordered proteins in unexpected ways. We studied the aggregation of a peptide derived from the disordered FG nucleoporins which line the nuclear pore complex. We measured its aggregation kinetics in the presence of both inert and non-specifically interacting crowding agents. Using fluorescence emission and NMR spectroscopy, we probed differences in the local chemical microenvironment of the peptide’s residues. Our results indicate differences in aggregation kinetics and residue microenvironment depending on the identity of the crowder, including differences between crowding with PEG and PVP, two polymers which are often used interchangeably as inert crowding agents.