| Autor: |
Amsdr, Alah, Noudeh, Negar Dehghan, Liu, Lutan, Chalikian, Tigran V. |
| Předmět: |
|
| Zdroj: |
Journal of Chemical Physics; 6/7/2019, Vol. 150 Issue 21, pN.PAG-N.PAG, 8p, 5 Charts, 6 Graphs |
| Abstrakt: |
The denaturing or stabilizing influence of a cosolvent on a protein structure is governed by a fine balance of the energetics of the excluded volume effect and the energetics of direct protein-cosolvent interactions. We have previously characterized the energetic contributions of excluded volume and direct interactions with urea for proteins and protein groups. In this work, we examine the molecular origins underlying the relatively weak temperature and urea dependences of the m-values of globular proteins. Our combined experimental and computational results collectively paint a picture in which the relative independence of protein m-values of urea concentration originates from fortuitous compensatory effects of a progressive increase in the solvent-accessible surface area of the unfolded state and a slightly higher urea binding constant of the unfolded state relative to the folded state. Other denaturing cosolvents which lack such a compensation make poor candidates for linear extrapolation model-based protein stability determination studies. The observed diminution in m-values with increasing temperature reflects, in addition to the aforementioned compensatory effects, a decrease in protein-urea binding constants with temperature in accordance with the negative sign of the binding enthalpy. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
