How a vicinal layer of solvent modulates the dynamics of proteins

Atılgan, Canan and Aykut, Ayşe Özlem and Atılgan, Ali Rana (2008) How a vicinal layer of solvent modulates the dynamics of proteins. Biophysical Journal, 94 . pp. 79-89. ISSN 0006-3495

This is the latest version of this item.

PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader

Official URL: http://dx.doi.org/10.1529/biophysj.107.116426


The dynamics of a folded protein is studied in water and glycerol at a series of temperatures below and above their respective dynamical transition. The system is modeled in two distinct states whereby the protein is decoupled from the bulk solvent at low temperatures, and communicates with it through a vicinal layer at physiological temperatures. A linear viscoelastic model elucidates the less-than-expected increase in the relaxation times observed in the backbone dynamics of the protein. The model further explains the increase in the flexibility of the protein once the transition takes place and the differences in the flexibility under the different solvent environments. Coupling between the vicinal layer and the protein fluctuations is necessary to interpret these observations. The vicinal layer is postulated to form once a threshold for the volumetric fluctuations in the protein to accommodate solvents of different sizes is reached. Compensation of entropic-energetic contributions from the protein-coupled vicinal layer quantifies the scaling of the dynamical transition temperatures in various solvents. The protein adapts different conformational routes for organizing the required coupling to a specific solvent, which is achieved by adjusting the amount of conformational jumps in the surface-group dihedrals.

Item Type:Article
ID Code:8611
Deposited By:Canan Atılgan
Deposited On:10 Jun 2008 13:21
Last Modified:25 May 2011 14:08

Available Versions of this Item

Repository Staff Only: item control page