title: Energetics of glycerol conduction through aquaglyceroporin GlpF.
abstract: Aquaglyceroporin GlpF selectively conducts water and linear polyalcohols, such as glycerol, across the inner membrane of Escherichia coli. We report steered molecular dynamics simulations of glycerol conduction through GlpF, in which external forces accelerate the transchannel conduction in a manner that preserves the intrinsic conduction mechanism. The simulations reveal channel-glycerol hydrogen bonding interactions and the stereoselectivity of the channel. Employing Jarzynski's identity between free energy and irreversible work, we reconstruct the potential of mean force along the conduction pathway through a time series analysis of molecular dynamics trajectories. This potential locates binding sites and barriers inside the channel; it also reveals a low energy periplasmic vestibule suited for efficient uptake of glycerol from the environment.
authors: Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors: Morten Ø
authors: MØ
authors: Jensen
authors: Sanghyun
authors: S
authors: Park
authors: Emad
authors: E
authors: Tajkhorshid
authors: Klaus
authors: K
authors: Schulten
mesh_terms: D020346:Aquaporins / Q000737:chemistry*; D003198:Computer Simulation; D004735:Energy Transfer; D029968:Escherichia coli Proteins / Q000737:chemistry*; D005990:Glycerol / Q000737:chemistry*; D008958:Models, Molecular
chemical_list: D020346:Aquaporins; D029968:Escherichia coli Proteins; C078043:GlpF protein, E coli; D005990:Glycerol