Thickness of the hydration layer of a protein from molecular dynamics simulation.
Water molecules around a protein exhibit slow dynamics with respect to that of pure bulk water. One important issue in protein hydration is the thickness of the hydration layer (i.e., the distance from the protein surface up to which the water dynamics is influenced by the protein). Estimation of thickness is crucial to understand better the properties of "biological water" and the role that it plays in guiding the protein's function. We have performed an atomistic molecular dynamics simulation of an aqueous solution of the protein villin headpiece subdomain or HP-36 to estimate the thickness of its hydration water. In particular, several dynamical properties of water around different segments (three alpha-helices) of the protein have been calculated by varying the thickness of the hydration layers. It is found that in general the influence of the helices on water properties extends beyond the first hydration layer. However, the heterogeneous nature of water among the first hydration layers of the three helices diminishes as the thickness is increased. It indicates that, for a small protein such as HP-36, the thickness of "biological water" is uniform for different segments of the protein.
Molecular Modeling Laboratory, Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India.
Sudipta Kumar
SK
Sinha
Sudip
S
Chakraborty
Sanjoy
S
Bandyopadhyay
D006860:Hydrogen Bonding; D008958:Models, Molecular; D009038:Motion; D016900:Neurofilament Proteins / Q000737:chemistry* / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism; D017433:Protein Structure, Secondary; D013997:Time Factors; D014867:Water / Q000737:chemistry* / Q000378:metabolism
D016900:Neurofilament Proteins; D010446:Peptide Fragments; C115223:villin headpiece subdomain peptide; D014867:Water