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| Type |
Poster Presentation |
| Area |
물리화학 |
| Room No. |
포스터발표장 |
| Time |
4월 20일 (목요일) 11:00~12:30 |
| Code |
PHYS.P-33 |
| Subject |
Dynamics of Hydration Water Plays a Key Role in Determining the Binding Thermodynamics of Protein Complex |
| Authors |
정성호, 함시현*
숙명여자대학교 화학과, Korea
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| Abstract |
Interfacial waters are considered to play a crucial role in protein-protein interactions, but in what sense and why are they important? Here, using molecular dynamics simulations and statistical thermodynamic analyses, we demonstrate distinctive dynamic characteristics of the interfacial water and investigate their implications for the binding thermodynamics. Molecular dynamics simulations identify the presence of extraordinarily slow (>1,000 slower than in bulk water) hydrogen-bond rearrangements in interfacial water. To elucidate their molecular origin, we introduce the “trapping” free energies of individual hydration water molecules, which characterize how strongly each water molecule is captured by the biomolecular surface. The thermodynamic-dynamic relationship diagram constructed with the hydrogen-bond relaxation times and trapping free energies clearly accounts, in molecular terms, for the emergence of the slow relaxation in the interfacial region upon protein-protein complex formation. We also discuss the impact of the slow interfacial waters on protein-protein interactions by quantifying their contribution to the standard binding free energy. We find that, as expected from their slow dynamics, the conventional approach to the water-mediated interaction, which assumes rapid equilibration of the waters' degrees of freedom, is inadequate. We show instead that an explicit treatment of the extremely slow interfacial water molecules is critical. Our results shed new light on the role of water in protein-protein interactions, highlighting the need to consider its dynamics to improve our understanding of biomolecular bindings. |
| E-mail |
songho.chong@gmail.com |
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119th General Meeting of the KCS