%0 Book Section %1 statphys23_0766 %A Oleinikova, A. %A Brovchenko, I. %B Abstract Book of the XXIII IUPAP International Conference on Statistical Physics %C Genova, Italy %D 2007 %E Pietronero, Luciano %E Loreto, Vittorio %E Zapperi, Stefano %K biological biomolecule function hydration percolation statphys23 topic-10 transition water %T Percolating water networks in biosystems %U http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=766 %X The presence of water at the surface of biomolecules is necessary for their conformational stability and function. Experimental studies show that physiological activity of some biosystems appear rapidly at some critical hydration level. Although the minimal amount of water depends on the biomolecule and the function considered, this hydration level is, typically, below the monolayer coverage of a biosurface. It was found experimentally, that this hydration level is close to the percolation threshold of water 1. In the low-hydrated systems water is localized in the vicinity of a biosurface and, accordingly, its percolation transition has quasi-two-dimensional character. We propose a new characterization of the hydration water based on the percolation theory. There are two qualitatively different states of water in hydration shell: an ensemble of small clusters and a hydrogen-bonded spanning network, which homogeneously envelopes a biomolecule. The formation of a spanning water network occurs via an intrinsically rounded quasi-two-dimensional percolation transition. We developed the methods to study the percolation transition of hydration water at the surface of a finite object, including the surface of a biomolecule 2-4. Hydration water may undergo a percolation transition when the hydration level, temperature or pressure is varied 3-10. We have found that this percolation transition of hydration water is closely related to the conformational transitions of hydrated proteins and DNA and to the qualitative changes in the dynamics of hydrated biosystems 5-10. The analysis of the various physical properties when crossing the percolation threshold should help to clarify the physical mechanisms behind the crucial role of percolating water network for biofunctions.\\ 1) J.A.Rupley and G.Careri, Adv.Protein.Chem., 41, 37 (1991).\\ 2) A.Oleinikova, I.Brovchenko, A.Geiger. Physica A 364, 1 (2006).\\ 3) A.Oleinikova, N.Smolin, I.Brovchenko, A.Geiger, R.Winter. J.Phys.Chem. B, 109, 1988 (2005)\\ 4) N.Smolin, A.Oleinikova, I.Brovchenko, A.Geiger, R.Winter. J.Phys.Chem. B, 109, 10995 (2005)\\ 5) I.Brovchenko, A.Krukau, N.Smolin, A.Oleinikova, A.Geiger, R.Winter. J.Chem. Phys. , 123, 224905 (2005).\\ 6) A.Oleinikova, I.Brovchenko, N.Smolin, A.Krukau, A.Geiger, R.Winter. Phys. Rev.Lett. 95, 247802 (2005)\\ 7) I.Brovchenko, A.Krukau, A.Oleinikova, A.Mazur. Phys.Rev.Lett. 97, 137801 (2006)\\ 8) A.Oleinikova, N. Smolin, and I.Brovchenko. J.Phys.Chem. B 110, 19619 (2006) \\ 9) A.Oleinikova and I.Brovchenko, Mol.Phys. 104, 3841 (2006)\\ 10) I.Brovchenko, A.Krukau, A.Oleinikova, A.Mazur. J.Phys. Chem. B, 111, 3258 (2007).

@incollection{statphys23_0766, abstract = {The presence of water at the surface of biomolecules is necessary for their conformational stability and function. Experimental studies show that physiological activity of some biosystems appear rapidly at some critical hydration level. Although the minimal amount of water depends on the biomolecule and the function considered, this hydration level is, typically, below the monolayer coverage of a biosurface. It was found experimentally, that this hydration level is close to the percolation threshold of water [1]. In the low-hydrated systems water is localized in the vicinity of a biosurface and, accordingly, its percolation transition has quasi-two-dimensional character. We propose a new characterization of the hydration water based on the percolation theory. There are two qualitatively different states of water in hydration shell: an ensemble of small clusters and a hydrogen-bonded spanning network, which homogeneously envelopes a biomolecule. The formation of a spanning water network occurs via an intrinsically rounded quasi-two-dimensional percolation transition. We developed the methods to study the percolation transition of hydration water at the surface of a finite object, including the surface of a biomolecule [2-4]. Hydration water may undergo a percolation transition when the hydration level, temperature or pressure is varied [3-10]. We have found that this percolation transition of hydration water is closely related to the conformational transitions of hydrated proteins and DNA and to the qualitative changes in the dynamics of hydrated biosystems [5-10]. The analysis of the various physical properties when crossing the percolation threshold should help to clarify the physical mechanisms behind the crucial role of percolating water network for biofunctions.\\ 1) J.A.Rupley and G.Careri, Adv.Protein.Chem., 41, 37 (1991).\\ 2) A.Oleinikova, I.Brovchenko, A.Geiger. Physica A 364, 1 (2006).\\ 3) A.Oleinikova, N.Smolin, I.Brovchenko, A.Geiger, R.Winter. J.Phys.Chem. B, 109, 1988 (2005)\\ 4) N.Smolin, A.Oleinikova, I.Brovchenko, A.Geiger, R.Winter. J.Phys.Chem. B, 109, 10995 (2005)\\ 5) I.Brovchenko, A.Krukau, N.Smolin, A.Oleinikova, A.Geiger, R.Winter. J.Chem. Phys. , 123, 224905 (2005).\\ 6) A.Oleinikova, I.Brovchenko, N.Smolin, A.Krukau, A.Geiger, R.Winter. Phys. Rev.Lett. 95, 247802 (2005)\\ 7) I.Brovchenko, A.Krukau, A.Oleinikova, A.Mazur. Phys.Rev.Lett. 97, 137801 (2006)\\ 8) A.Oleinikova, N. Smolin, and I.Brovchenko. J.Phys.Chem. B 110, 19619 (2006) \\ 9) A.Oleinikova and I.Brovchenko, Mol.Phys. 104, 3841 (2006)\\ 10) I.Brovchenko, A.Krukau, A.Oleinikova, A.Mazur. J.Phys. Chem. B, 111, 3258 (2007).}, added-at = {2007-06-20T10:16:09.000+0200}, address = {Genova, Italy}, author = {Oleinikova, A. and Brovchenko, I.}, biburl = {https://www.bibsonomy.org/bibtex/2d3ed858c9a07752c01ebb2734c2b3ceb/statphys23}, booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics}, editor = {Pietronero, Luciano and Loreto, Vittorio and Zapperi, Stefano}, interhash = {e91037c98c6a5594f645cf43cb4cd6f2}, intrahash = {d3ed858c9a07752c01ebb2734c2b3ceb}, keywords = {biological biomolecule function hydration percolation statphys23 topic-10 transition water}, month = {9-13 July}, timestamp = {2007-06-20T10:16:29.000+0200}, title = {Percolating water networks in biosystems}, url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=766}, year = 2007 }