Molecular dynamics insights into human aquaporin 2 water channel

- The first molecular dynamics simulation of the human aquaporin 2 is performed.
- The osmotic and diffusive permeability constants of AQP2 are provided.
- Water permeation in human AQP2 occurs in ideal single-file fashion.
- The MD results of AQP2 give insights into kidney urine concentration process.

In this study, the first molecular dynamics simulation of the human aquaporin 2 is performed and for a better understanding of the aquaporin 2 permeability performance, the characteristics of water transport in this protein channel and key biophysical parameters of AQP2 tetramer including osmotic and diffusive permeability constants and the pore radius are investigated. For this purpose, recently recovered high resolution X-ray crystal structure of` the human aquaporin 2 is used to perform twenty nanosecond molecular dynamics simulation of fully hydrated tetramer of this protein embedded in a lipid bilayer. The resulting water permeability characteristics of this protein channel showed that the water permeability of the human AQP2 is in a mean range in comparison with other human aquaporins family. Finally, the results reported in this research demonstrate that molecular dynamics simulation of human AQP2 provided useful insights into the mechanisms of water permeation and urine concentration in the human kidney.