Temperature effects on hydrophobic interactions: Implications for protein unfolding

According to our recent studies on hydrophobic interactions, this work is devoted to investigate the temperature effects on hydrophobic interactions. Regarding to hydrophobic interactions, they are due to the structural competition between bulk and interfacial water. The water structure may be influenced by temperature, which undoubtedly affects the hydrophobic interactions. For the temperature effects on hydrophobic interactions, they are related to the size of solute. This is reflected on the dependence of Rc (critical radius) on temperature. With increasing temperature, it leads to the decrease of Rc. Additionally, this can be demonstrated by the calculated PMFs (potential mean force) between a pair of CH4 molecules through MD (molecular dynamics) simulations. Based on the temperature effects on hydrophobic interactions, it is applied to understand the dependence of protein stability on temperature, such as cold denaturation and heat unfolding. Regarding to the molecular mechanism, cold denaturation is different from heat unfolding.