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AvtorStare, Jernej
Mavri, Janez
Grdadolnik, Jože
Zidar, Jernej
Maksić, Zvonimir B.
Vianello, Robert
Naslov Hydrogen bond dynamics of histamine monocation in aqueous solution : Car-Parrinello molecular dynamics and vibrational spectroscopy study / Jernej Stare ... [et al.]
Vrsta/vsebinatype of material članek - sestavni del
Fizični opisstr. 5999-6010
OpombeSodelavci: Janez Mavri, Jože Grdadolnik, Jernej Zidar, Zvonimir B. Maksić, Robert Vianello
Bibliografija: str. 6009-6010
Predmetne oznake (nekontrolirane)strukturna kemija / molekularna dinamika / spektroskopija
PovzetekHydration of histamine was examined by infrared spectroscopy and Car-Parrinello molecular dynamics simulation. Histamine is a neurotransmitter and inflammation mediator, which at physiological pH conditions is present mainly in monocationic form. Our focus was on the part of vibrational spectra that corresponds to histamine N-H stretching, since these degrees of freedom are essential for its interactions with either water molecules or transportersand receptors. Assignment of the experimental spectra revealed a broad feature between 3350 and 2300 cm(-1), being centered at 2950 cm(-1), which includes a mixed contribution from the ring N-H and the aminoethyl N-H stretching vibrations. Computational analysis was performed in two ways: first, by making Fourier transformation on the autocorrelation function of allfour N-H bond distances recorded during CPMD run, and second, and most importantly, by incorporating quantum effects through applying an a posterioriquantization of all N-H stretching motions utilizing our snapshot analysis of the fluctuating proton potential. The one-dimensional vibrational Schro dinger equation was solved numerically for each snapshot, and the N-H stretching envelopes were calculated as a superposition of the 0>1 transitions. The agreement with the experiment was much better in the case of the second approach. Our calculations clearly demonstrated that the ring aminogroup absorbs at higher frequencies than the remaining three amino N-H protons of the protonated aminoethyl group, implying that the chemical bondingin the former group is stronger than in the three amino N-H bonds, thusforming weaker hydrogen bonding with the surrounding solvent molecules. Inthis way the results of the simulation complemented the experimental spectrum that cannot distinguish between the two sets of protons. The effects of deuteration were also considered. The resulting N-D absorption is narrower and red-shifted. The presented methodology is of general applicability to strongly correlated systems, and it is particularly tuned to provide computational support to vibrational spectroscopy. Perspectives are given for its future applications in computational studies of tunneling in enzyme reactive centers and for receptor activation.
Glej publikacijo TI=The journal of physical chemistry. B, Condensed matter, materials, surfaces, interfaces & biophysical ISSN: 1520-6106.- Vol. 115, no. 19 (2011), str. 5999-6010

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