RT Journal Article SR Electronic T1 Dramatic influence of patchy attractions on short-time protein diffusion under crowded conditions JF Science Advances JO Sci Adv FD American Association for the Advancement of Science SP e1601432 DO 10.1126/sciadv.1601432 VO 2 IS 12 A1 Bucciarelli, Saskia A1 Myung, Jin Suk A1 Farago, Bela A1 Das, Shibananda A1 Vliegenthart, Gerard A. A1 Holderer, Olaf A1 Winkler, Roland G. A1 Schurtenberger, Peter A1 Gompper, Gerhard A1 Stradner, Anna YR 2016 UL http://advances.sciencemag.org/content/2/12/e1601432.abstract AB In the dense and crowded environment of the cell cytoplasm, an individual protein feels the presence of and interacts with all surrounding proteins. While we expect this to strongly influence the short-time diffusion coefficient Ds of proteins on length scales comparable to the nearest-neighbor distance, this quantity is difficult to assess experimentally. We demonstrate that quantitative information about Ds can be obtained from quasi-elastic neutron scattering experiments using the neutron spin echo technique. We choose two well-characterized and highly stable eye lens proteins, bovine α-crystallin and γB-crystallin, and measure their diffusion at concentrations comparable to those present in the eye lens. While diffusion slows down with increasing concentration for both proteins, we find marked variations that are directly linked to subtle differences in their interaction potentials. A comparison with computer simulations shows that anisotropic and patchy interactions play an essential role in determining the local short-time dynamics. Hence, our study clearly demonstrates the enormous effect that weak attractions can have on the short-time diffusion of proteins at concentrations comparable to those in the cellular cytosol.