title: Structural and dynamical studies of Humanin in water and TFE/water mixture: a molecular dynamics simulation.
abstract: The structural and dynamical properties of Humanin, a small peptide with neuroprotective activity against the insults of the Alzheimer's disease-related genes and the neurotoxic amyloid peptide, are studied in two different environments by molecular dynamics simulation. In this study, we have performed comparative molecular dynamics simulations in the absence and in the presence of TFE. The resulting trajectories were analyzed in terms of structural and dynamical properties of peptide and compared to the available NMR data. In water humanin is observed to partly unfold. The peptide is readily stabilized in an ordered helical conformation in the TFE/water mixture. Our simulations show that the peptide is flexible with definite turn point in its structure in water environment. It is free to interact with receptors that mediate its action in polar environment. Humanin may also find an alpha helix structure necessary for passage through biomembranes and/or specific interactions.
authors.affiliation: Department of Biology, Faculty of Science, Azarbaijan University of Tarbiat Moallem, Tabriz, Iran. Mehrnejad@azaruniv.edu
authors.forename: Faramarz
authors.initials: F
authors.lastname: Mehrnejad
authors.forename: Nader
authors.initials: N
authors.lastname: Chaparzadeh
mesh_terms: D000544:Alzheimer Disease / Q000517:prevention & control; D003198:Computer Simulation; D006801:Humans; D006860:Hydrogen Bonding; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D018696:Neuroprotective Agents / Q000737:chemistry*; D017433:Protein Structure, Secondary; D014270:Trifluoroethanol / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D018696:Neuroprotective Agents; C427211:humanin; D014867:Water; D014270:Trifluoroethanol