Abstract
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, andmeasure 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.
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, andmeasure 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.
Originalsprog | Engelsk |
---|---|
Artikelnummer | e1601432 |
Tidsskrift | Science Advances |
Vol/bind | 2 |
Antal sider | 8 |
ISSN | 2375-2548 |
Status | Udgivet - 7 dec. 2016 |
Udgivet eksternt | Ja |