title: Vibrational dynamics of hydrogen in proteins.
abstract: Biological macromolecules expand with increasing temperature and this dynamic expansion is associated with the onset of function. The expansion is typically characterized by the mean square vibrational displacement (MSD), <u²> of specific constituents such as hydrogen within the macromolecules. The <u²> increases with increasing temperature and the slope of <u²> versus temperature can increase significantly at a temperature T{D} identified as a dynamical transition. We illustrate that the observed expansion and change in slope of <u²> with temperature at T{D} can be reproduced within a simple model of the vibration, an atom in an anharmonic potential, V(u). Given V(u), only the temperature is varied in the model. A simple Gaussian potential or a potential containing a hard wall is particularly effective is reproducing the observed change in the slope of <u²> with temperature around T{D}.
authors.affiliation: Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716-2570, USA.
authors.forename: Derya
authors.initials: D
authors.lastname: Vural
authors.forename: Henry R
authors.initials: HR
authors.lastname: Glyde
mesh_terms: D000818:Animals; D004247:DNA / Q000737:chemistry; D006801:Humans; D006859:Hydrogen / Q000737:chemistry*; D006860:Hydrogen Bonding; D046911:Macromolecular Substances / Q000737:chemistry*; D008954:Models, Biological; D015233:Models, Statistical; D008962:Models, Theoretical; D009502:Neutrons; D016011:Normal Distribution; D011506:Proteins / Q000737:chemistry*; D012313:RNA / Q000737:chemistry; D012542:Scattering, Radiation; D013696:Temperature
chemical_list: D046911:Macromolecular Substances; D011506:Proteins; D012313:RNA; D006859:Hydrogen; D004247:DNA