These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Direct evidence of the amino acid side chain and backbone contributions to protein anharmonicity.
    Author: Schiró G, Caronna C, Natali F, Cupane A.
    Journal: J Am Chem Soc; 2010 Feb 03; 132(4):1371-6. PubMed ID: 20067251.
    Abstract:
    Elastic incoherent neutron scattering has been used to study the temperature dependence of the mean-square displacements of nonexchangeable hydrogen atoms in powders of a series of homomeric polypeptides (polyglycine, polyalanine, polyphenylalanine and polyisoleucine) in comparison with myoglobin at the same hydration level (h = 0.2). The aim of the work was to measure the dynamic behavior of different amino acid residues separately and assess the contribution of each type of side chain to the anharmonic dynamics of proteins. The results provide direct experimental evidence that the first anharmonic activation, at approximately 150 K, is largely due to methyl group rotations entering the time window of the spectrometer used; however, contributions on the order of 10-20% from the motions of other groups (e.g., the phenolic ring and the methylene groups) are present. Our data also indicate that the dynamical transition occurring at approximately 230 K can be attributed, at least at the hydration level investigated, mainly to motions involving backbone fluctuations.
    [Abstract] [Full Text] [Related] [New Search]