 | Exploring Protein Motors on Atomic Scale
Ilya Balabin, Alek Aksimentiev, and Klaus Schulten
Beckman Institute for Advanced Science and Technology, UIUC, US
Keywords: molecular motor, energy conversion, molecular dynamics
Abstract:
Protein motors are ultimate molecular devices capable of reversible,
nearly 100% efficient conversion between mechanical and chemical
(electrochemical) energy. Understanding the principles underlying the
protein motor function may facilitate development of nanodevices with
unsurpassed efficiency and performance.
We present the first ever all-atom molecular dynamics (MD) simulation
of the F0 unit of ATP synthase from E. coli. ATP synthase is an
exemplar ubiquitous protein motor that converts a transmembrane proton
gradient to a mechanical torque, which drives synthesis of ATP, the
"energy currency" in all living organisms. This large (~450 kDa)
protein consists of a transmembrane unit F0 and a solvent-exposed unit
F1, coupled via a central stalk.
We have built two structures of the F0 unit embedded in a POPE
membrane, solvated, ionized, and equilibrated. Several MD techniques
including steered MD were combined to identify and explore the chain
of elementary chemical (protonation or deprotonation of protein
residues) and mechanical (protein domain motion) events in the process
of proton transfer across the membrane. A possible scenario for these
events was elaborated, and the relevant energies were estimated. These
preliminary results provide a better insight into the protein motor
function and its relationship to structure.
NSTI Nanotech 2003 Conference Technical Program Abstract
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