It has been shown that the hydration structure and dynamics in crowded environment are significantly affected by protein crowders, as a function of volume fraction. However, at the same volume fraction, whether this crowding effect on water remains unchanged in different-sized crowders is still unknown. In this study, we investigate the influence of protein crowder size on hydration structure and dynamics in protein-crowding systems using all-atom molecular dynamics (MD) simulations. The crowded systems consisting of only small proteins exhibited larger total surface areas than those of large proteins at the same volume fractions. As a result, more water molecules were trapped within the hydration shells, slowing down water diffusion. Calculated rotational diffusion times and water residence times were also elongated in the systems of small proteins. Our results suggest that the protein crowder size is another important factor to determine the effect of macromolecular crowding and to explain the experimental kinetic data of proteins and DNAs in the presence of crowding agents.

Influence of protein crowder size on hydration structure and dynamics in macromolecular crowding

254th National Meeting (2017)

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