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Titolo:
Incoherent neutron scattering of copper azurin: a comparison with molecular dynamics simulation results
Autore:
Paciaroni, A; Stroppolo, ME; Arcangeli, C; Bizzarri, AR; Desideri, A; Cannistraro, S;
Indirizzi:
Univ Perugia, Dipartimento Fis, Unita INFM, I-06100 Perugia, Italy Univ Perugia Perugia Italy I-06100 s, Unita INFM, I-06100 Perugia, Italy Univ Tuscia, Dipartimento Sci Ambientali, I-01100 Viterbo, Italy Univ Tuscia Viterbo Italy I-01100 Sci Ambientali, I-01100 Viterbo, Italy Univ Roma Tor Vergata, Dipartimento Biol, Unita INFM, I-00133 Rome, Italy Univ Roma Tor Vergata Rome Italy I-00133 Unita INFM, I-00133 Rome, Italy
Titolo Testata:
EUROPEAN BIOPHYSICS JOURNAL WITH BIOPHYSICS LETTERS
fascicolo: 6, volume: 28, anno: 1999,
pagine: 447 - 456
SICI:
0175-7571(1999)28:6<447:INSOCA>2.0.ZU;2-Q
Fonte:
ISI
Lingua:
ENG
Soggetto:
LOW-FREQUENCY MOTIONS; GLASS-TRANSITION; PROTEIN DYNAMICS; GLOBULAR-PROTEINS; RAMAN-SPECTRA; MYOGLOBIN; MODES; WATER; BACTERIORHODOPSIN; SPECTROSCOPY;
Keywords:
protein dynamics; hydration water; glassy dynamics; boson peak;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
61
Recensione:
Indirizzi per estratti:
Indirizzo: Cannistraro, S Univ Perugia, Dipartimento Fis, Unita INFM, I-06100 Perugia, Italy Univ Perugia Perugia Italy I-06100 I-06100 Perugia, Italy
Citazione:
A. Paciaroni et al., "Incoherent neutron scattering of copper azurin: a comparison with molecular dynamics simulation results", EUR BIOPHYS, 28(6), 1999, pp. 447-456

Abstract

The low-frequency dynamics of copper azurin has been studied at different temperatures for a dry and deuterium hydrated sample by incoherent neutron scattering and the experimental results have been compared with molecular dynamics (MD) simulations carried our in the same temperature range. Experimental Debye-Waller factors are consistent with a dynamical transition at approximately 200 K which appears partially suppressed in the dry sample. Inelastic and quasielastic scattering indicate that hydration water modulates both vibrational and diffusive motions. The low-temperature experimental dynamical structure factor of the hydrated protein shows an excess of inelastic scattering peaking at about 3 meV and whose position is slightly shifteddownwards in the dry sample. Such an excess is reminiscent of the "boson peak" observed in glass-like materials. This vibrational peak is quite well reproduced by MD simulations, although at a lower energy. The experimental quasielastic scattering of the two samples at 300 K shows a two-step relaxation behaviour with similar characteristic times, while the corresponding intensities differ only by a scale factor. Also, MD simulations confirm the two-step diffusive trend, but the slow process seems to be characterized bya decay faster than the experimental one. Comparison with incoherent neutron scattering studies carried out on proteins having different structure indicates that globular proteins display common elastic, quasielastic and inelastic features, with an almost similar hydration dependence, irrespective of their secondary and tertiary structure.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/12/20 alle ore 03:39:19