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3ВОДНЫЕ РАСТВОРЫ В БИОЛОГИЧЕСКИХ СИСТЕМАХ
HYDRATION LAYER OF CONDUCTING PROTEINS DEMONSTRATES SPECTRAL FEATURES OF FLOATING WATER BRIDGES IN THE THz-IR FREQUENCY RANGE
Motovilov K., Gorshunov B., Gagkayeva Z.
Moscow Institute of Physics and Technology, Institutsky lane 9, build. 2, Dolgoprudny, Russia, 141701
k.a.motovilov@gmail.com
The groups of Teschke, Fuchs, and Wexler have done groundbreaking work on the properties of floating water bridges in recent years. They revealed several essential traits in the dielectric response of these dynamic systems [1]. Among them is a sharp increase in the contribution of translational vibrations to the dielectric response near 200cm-1 and signs of predominance among other aqueous proton cations of the hydronium cation H3O+. In one of the most well-studied proton conductors - heteropolyacids (HPA) family H3PW12O40 x nH2O - the prevalence of H3O+ features the increased proton mobility [2]. Our study found that the proteins responsible for electron and proton transfer in living organisms have similar spectral features to floating water bridges and HPA, which indicate increased proton mobility. We used cytochrome c from the bovine heart and electrogenic bacteria Shewanella oneidensis MR-1 in our study [3]. These proteins seem to structure water into electrically constrained form like in floating water bridges without the participation of a strong external electrical fields. Bovine serum albumin, a protein that doesn't assist in charge transfer, won't display the same spectral characteristics or charge conductivity as one that does, even if they have equal hydration level.
The Russian science foundation supported this work, grunt number 19-73-10154.
[1] O. Teschke, J.R. Castro, D.M. Soares, Translational vibration modes - The spectral signature of excess proton transport in water, Physics of Fluids, vol. 30, 112104, (2018).
[2] D.I. Kolokolov, M.S. Kazantsev, M.V. Luzgin, H. Jobic, A.G. Stepanov, Characterization and Dynamics of the Different Protonic Species in Hydrated 12-Tungstophosphoric Acid Studied by 2H NMR, The Journal of Physical Chemistry C, vol. 118, pp. 3002330033, (2014).
[3] Z.V Gagkayeva, B.P. Gorshunov, A.Ye. Kachesov, K.A. Motovilov,. Infrared fingerprints of water collective dynamics indicate proton transport in biological systems, Physical Review E, vol. 105, 044409 (2022).
