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Titolo:
Glasslike dynamical behavior of the plastocyanin hydration water
Autore:
Bizzarri, AR; Paciaroni, 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
Titolo Testata:
PHYSICAL REVIEW E
fascicolo: 3, volume: 62, anno: 2000,
parte:, B
pagine: 3991 - 3999
SICI:
1063-651X(200009)62:3<3991:GDBOTP>2.0.ZU;2-1
Fonte:
ISI
Lingua:
ENG
Soggetto:
INELASTIC NEUTRON-SCATTERING; POTENTIAL-ENERGY FLUCTUATIONS; LOW-FREQUENCY MODES; MOLECULAR-DYNAMICS; 1/F NOISE; COPPER PLASTOCYANIN; SUPERCOOLED WATER; MD SIMULATION; RAMAN-SPECTRA; BOSON PEAK;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
--discip_EC--
Citazioni:
65
Recensione:
Indirizzi per estratti:
Indirizzo: Bizzarri, AR Univ Perugia, Dipartimento Fis, Unita INFM, I-06100 Perugia, Italy Univ Perugia Perugia Italy I-06100 , I-06100 Perugia, Italy
Citazione:
A.R. Bizzarri et al., "Glasslike dynamical behavior of the plastocyanin hydration water", PHYS REV E, 62(3), 2000, pp. 3991-3999

Abstract

The dynamical behavior of water around plastocyanin has been investigated in a wide temperature range by molecular dynamics simulation. The mean square displacements of water oxygen atoms show, at long times, a ta trend for all temperatures. Below 150 K, alpha is constant and equal to 1; at higher temperatures it drops to a value significantly smaller than 1, and thereafter decreases with increasing temperature. The occurrence of such an anomalous diffusion matches the onset of the dynamical transition observed in the protein. The intermediate scattering function of water is characterized, athigh temperature, by a stretched exponential decay evolving, at low temperature, toward a two step relaxation behavior, which becomes more evident onincreasing the exchanged wave vector q. Both the mean square displacementsand the intermediate scattering functions show, beyond the ballistic regime, a plateau, which progressively extends for longer times as long as the temperature is lowered, such behavior reflecting trapping of water moleculeswithin a cage formed by the nearest neighbors. At low temperature, a low frequency broad inelastic peak is observed in the dynamical structure factorof hydration water; such an excess of vibrational modes being reminiscent of the boson peak, characteristic of disordered, amorphous systems. All these features, which are typical of complex systems, can be traced back to the glassy character of the hydration water and suggest a dynamical coupling occurring at the macromolecule-solvent interface.

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Documento generato il 28/11/20 alle ore 04:09:48