An Atomistic View of Solvent-Free Protein Liquids

An Atomistic View of Solvent-Free Protein Liquids

Using extensive atomistic molecular dynamics simulations of the hybrid liquid of Lipase A enzyme, we demonstrate that the inter-protein structure is comparable to inter-particle correlations in a noble gas fluid, after appropriate scaling of distances; the hydrophilic part of the surfactants form a coronal layer around each enzyme which percolates through the liquid, while their hydrophobic parts form disjointed clusters embedded in this layer. While the protein retains its native state conformational dynamics in the solvent-free form, the fluxionality of its side chains is much reduced.  Despite the sluggishness of the solvent-free enzyme, some water molecules exhibit high mobility and transit between enzymes primarily via the interspersed hydrophilic regions. These microscopic insights offer ideas to improve substrate diffusion in the liquid to enable the enhancement of catalytic activity.