title: Comparison of Implicit and Explicit Solvation Models for Iota-Cyclodextrin Conformation Analysis from Replica Exchange Molecular Dynamics.
abstract: Large ring cyclodextrins have become increasingly important for drug delivery applications. In this work, we have performed replica-exchange molecular dynamics simulations using both implicit and explicit water solvation models to study the conformational diversity of iota-cyclodextrin containing 14 α-1,4 glycosidic linked d-glucopyranose units (CD14). The new quantifiable calculation methods are proposed to analyze the openness, bending, and twisted conformation of CD14 in terms of circularity, biplanar angle, and one-directional conformation (ODC). CD14 in GB implicit water model (Igb5) was found mostly in an opened conformation with average circularity of 0.39 ± 0.16 and a slight bend with average biplanar angle of 145.5 ± 16.0°. In contrast, CD14 in TIP3P explicit water solvation is significantly twisted with average circularity of 0.16 ± 0.10, while 29.1% are ODCs. In addition, classification of CD14 conformations using a Gaussian mixture model (GMM) shows that 85.0% of all CD14 in implicit water at 300 K correspond to the elliptical conformation, in contrast to 82.3% in twisted form in explicit water. GMM clustering also reveals minority conformations of CD14 such as the 8-shape, boat-form, and twisted conformations. This work provides fundamental insights into CD14 conformation, influence of solvation models, and also proposes new quantifiable analysis techniques for molecular conformation studies in the future.
authors.forename: Wasinee
authors.initials: W
authors.lastname: Khuntawee
authors.affiliation: National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA) , Pathum Thani 12120, Thailand.
authors.forename: Manaschai
authors.identifier: 0000-0002-1327-2502
authors.initials: M
authors.lastname: Kunaseth
authors.affiliation: National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA) , Pathum Thani 12120, Thailand.
authors.forename: Chompoonut
authors.initials: C
authors.lastname: Rungnim
authors.affiliation: Department of Mathematics, Statistics and Computer Science, Kasetsart University , Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand.
authors.forename: Suradej
authors.initials: S
authors.lastname: Intagorn
authors.forename: Peter
authors.initials: P
authors.lastname: Wolschann
authors.affiliation: Department of Chemistry, Faculty of Science, Chiang Mai University , 239 Huay Kaew Road, Muang District, Chiang Mai 50200, Thailand.
authors.forename: Nawee
authors.initials: N
authors.lastname: Kungwan
authors.forename: Thanyada
authors.initials: T
authors.lastname: Rungrotmongkol
authors.forename: Supot
authors.initials: S
authors.lastname: Hannongbua
mesh_terms: D002236:Carbohydrate Conformation; D003505:Cyclodextrins / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D012997:Solvents / Q000737:chemistry; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D003505:Cyclodextrins; D012997:Solvents; D014867:Water