A Closer Atomistic Look to Evolution of Active Nanopores of The Human Tetrameric Aquaporin-1
Paper ID : 1146-ICNS
Shaghayegh Bahari1, Seyed Vahid Mohammadi2, Reza Davarnejad1, Omid Bavi *3
1Department of Chemical Engineering, School of Engineering, Arak University, Arak
2Inspection Department Arak Petrochemical Complex, Arak
3Department of Mechanical and Aerospace Engineering, Shiraz University of Technology, Shiraz
Aquaporins as a vast variety of membrane proteins are very active in water permeation into and out of biological cells. They seem extremely promising to be used in water desalination membranes. In this study the nanopores of the human tetrameric Aquaporin are scrutinized during hydration equilibrium. Different parameters like pore’s diameter variation along the pore axis and water occupancy in the nanochannel as well as water dynamics in the channel are investigated using molecular dynamic simulation. Results showed that during equilibrium nanopores conform very fast and pore’s diameter dramatically changes during equilibrium. Furthermore, channel in some areas becomes too narrow as if only one molecule can occupy the channel making a single file concerted water thread. This single file is broken very often during the simulation. Moreover, the narrowest vacancy in the channel is found here at residues ILE60 and ASN76 at the end of NPA region contrary to the common knowledge. Results provided in this study shed light on mechanism of water dynamics in AQP1 pores. It also provides the ground for further investigation on permeation manipulation by mutating key residues introduced here. Results also suggest that single chain of an AQP can be used for molecular dynamics studies instead of a tetramer which can save simulation time and cost.
Aquaporin-1, desalination, water nanochannel, Pore diameter, diffusive permeation
Status : Abstract Accepted (Poster Presentation)