Abstract

Recently, several experiments have investigated the relation between the dynamics of the hydration water and the dynamics of protein. These works have generated a large amount of data whose interpretation is debated. New experiments measure the dynamics of water at low temperature on the surface of proteins, finding a qualitative change (crossover) that might be related to the slowing down and stop of the protein’s activity (protein glass transition), possibly relevant for the safe preservation of organic material at low temperature. To better understand the experimental data several scenarios have been discussed [1]. Here, we review these experiments and discuss their interpretations [2,3] in relation with the anomalous properties [4] of bulk water [5] and confined water [6]. We summarize the results for bulk water and investigate the thermodynamic and dynamic properties of supercooled water at an interface [7]. We will consider also the effect of water on protein stability, making a step in the direction of understanding, by means of Monte Carlo simulations and theoretical calculations, how the interplay of water cooperativity and hydrogen bonds interfacial strengthening affects the protein cold denaturation [8].

[1] “Aspects of Physical Biology Biological Water, Protein Solutions, Transport and Replication”, Book Series: Lecture Notes in Physics , Vol. 752/2008, G. Franzese and M. Rubi (Eds.), Springer Berlin 2008, 280 p.

[2] G. Franzese, K. Stokely, X.-Q. Chu, P. Kumar, M. G. Mazza, S.-H. Chen, and H. E. Stanley, Pressure Effects in Supercooled Water: comparison between a 2D model of water and experiments for surface water on a protein, Journal of Physics: Condensed Matter 20, 494210 (2008).

[3] M. G. Mazza, K. Stokely, S. E. Pagnotta, F. Bruni, H. E. Stanley, and G. Franzese, Two dynamic crossovers in protein hydration water and their thermodynamic interpretation, arXiv:0907.1810v1 (2009).

[4] P. Kumar, G. Franzese, and H. E. Stanley, Predictions of Dynamic Behavior under Pressure for Two Scenarios to Explain Water Anomalies, Physical Review Letters 100, 105701 (2008).

[5] K. Stokely, M. G. Mazza, H. E. Stanley, and G. Franzese, Effect of hydrogen bond cooperativity on the behavior of water, Proceedings of the National Academy of Sciences 107, 1301 (2010).

[6] G. Franzese and F. de los Santos, Dynamically Slow Processes in Supercooled Water Confined Between Hydrophobic Plates, Journal of Physics: Condensed Matter, Journal of Physics: Condensed Matter 21, 504107 (2009).

[7] G. Franzese, A. Hernando-Martinez, P. Kumar, M. G. Mazza, K. Stokely, E. G. Strekalova, F. de los Santos, H. E. Stanley, Phase Transitions and Dynamics in Bulk and Interfacial Water, arXiv:0912.1666 (2009).

[8] S. Iskrov and G. Franzese, in preparation.