title: Temperature-dependent dynamical transitions of different classes of amino acid residue in a globular protein.
abstract: The temperature dependences of the nanosecond dynamics of different chemical classes of amino acid residue have been analyzed by combining elastic incoherent neutron scattering experiments with molecular dynamics simulations on cytochrome P450cam. At T = 100-160 K, anharmonic motion in hydrophobic and aromatic residues is activated, whereas hydrophilic residue motions are suppressed because of hydrogen-bonding interactions. In contrast, at T = 180-220 K, water-activated jumps of hydrophilic side chains, which are strongly coupled to the relaxation rates of the hydrogen bonds they form with hydration water, become apparent. Thus, with increasing temperature, first the hydrophobic core awakens, followed by the hydrophilic surface.
authors.affiliation: University of Tennessee/Oak Ridge National Laboratory Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.
authors.forename: Yinglong
authors.initials: Y
authors.lastname: Miao
authors.forename: Zheng
authors.initials: Z
authors.lastname: Yi
authors.forename: Dennis C
authors.initials: DC
authors.lastname: Glass
authors.forename: Liang
authors.initials: L
authors.lastname: Hong
authors.forename: Madhusudan
authors.initials: M
authors.lastname: Tyagi
authors.forename: Jerome
authors.initials: J
authors.lastname: Baudry
authors.forename: Nitin
authors.initials: N
authors.lastname: Jain
authors.forename: Jeremy C
authors.initials: JC
authors.lastname: Smith
mesh_terms: D000596:Amino Acids / Q000737:chemistry* / Q000145:classification; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D056004:Molecular Dynamics Simulation; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry*; D013696:Temperature
chemical_list: D000596:Amino Acids; D011506:Proteins