title: Molecular Insight into Different Denaturing Efficiency of Urea, Guanidinium, and Methanol: A Comparative Simulation Study.
abstract: We have designed various nanoslit systems, whose opposing surfaces can be either hydrophobic, hydrophilic, or simply a water-vapor interface, for the molecular dynamics simulation of confined water with three different protein denaturants, i.e., urea, guanidinium chloride (GdmCl), and methanol, respectively. Particular attention is placed on the preferential adsorption of the denaturant molecules onto the opposing surfaces and associated resident time in the vicinal layer next to the surfaces, as well as their implication in the denaturing efficiency of different denaturant molecules. Our simulation results show that among the three denaturants, the occupancy of methanol in the vicinal layer is the highest while the residence time of Gdm is the longest. Although the occupancy and the residence time of urea in the vicinal layer is less than those of the other two denaturant molecules, urea entails "all-around" properties for being a highly effective denaturant. The distinct characteristics of three denaturants may suggest a different molecular mechanism for the protein denaturation. This comparative simulation by design allows us to gain additional insights, on the molecular level, into the denaturation effect and related hydrophobic effect.
authors.affiliation: Department of Applied Physics, University of Fukui, 3-9-1 Bunkyo,Fukui 910-8507, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Koishi
authors.affiliation: Department of Mechanical Engineering, Keio University, Yokohama 223-8522, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Yasuoka
authors.affiliation: Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, South Korea.
authors.forename: Soohaeng Yoo
authors.initials: SY
authors.lastname: Willow
authors.affiliation: International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Shigenori
authors.initials: S
authors.lastname: Fujikawa
authors.affiliation: Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, United States.
authors.forename: Xiao Cheng
authors.initials: XC
authors.lastname: Zeng