title: Comparative dynamics of leucine methyl groups in FMOC-leucine and in a protein hydrophobic core probed by solid-state deuteron nuclear magnetic resonance over 7-324 K temperature range.
abstract: Quantitative dynamics of methyl groups in 9-fluorenylmethyloxycarbonyl-leucine (FMOC-leu) have been analyzed and compared with earlier studies of methyl dynamics in chicken villin headpiece subdomain protein (HP36) labeled at L69, a key hydrophobic core position. A combination of deuteron solid-state nuclear magnetic resonance experiments over the temperature range of 7-324 K and computational modeling indicated that while the two compounds show the same modes of motions, there are marked differences in the best-fit parameters of these motions. One of the main results is that the crossover observed in the dynamics of the methyl groups in the HP36 sample at 170 K is absent in FMOC-leu. A second crossover at around 95-88 K is present in both samples. The differences in the behavior of the two compounds suggest that some of the features of methyl dynamics reflect the complexity of the protein hydrophobic core and are not determined solely by local interactions.
authors.affiliation: University of Alaska-Anchorage, Anchorage, Alaska 99508, USA.
authors.forename: Liliya
authors.initials: L
authors.lastname: Vugmeyster
authors.forename: Dmitry
authors.initials: D
authors.lastname: Ostrovsky
authors.forename: Mark
authors.initials: M
authors.lastname: Moses
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Ford
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Lipton
authors.forename: Gina L
authors.initials: GL
authors.lastname: Hoatson
authors.forename: Robert L
authors.initials: RL
authors.lastname: Vold
mesh_terms: D000818:Animals; D002645:Chickens; D005449:Fluorenes / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D007930:Leucine / Q000737:chemistry*; D008968:Molecular Conformation; D016900:Neurofilament Proteins / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010446:Peptide Fragments / Q000737:chemistry*; D013696:Temperature
chemical_list: C496789:9-fluorenylmethoxycarbonyl; D005449:Fluorenes; D016900:Neurofilament Proteins; D010446:Peptide Fragments; C115223:villin headpiece subdomain peptide; D007930:Leucine