The role of water in proteins behavior: The two dynamical crossovers studied by NMR and FTIR techniques

Publication date: Available online 15 November 2014 Source:Computational and Structural Biotechnology Journal Author(s): Francesco Mallamace , Carmelo Corsaro , Domenico Mallamace , Sebastiano Vasi , Cirino Vasi , Giacomo Dugo The role the solvent plays in determining the biological activity of proteins is of primary importance. Water is the solvent of life and proteins need at least a water monolayer covering their surface in order to become biologically active. We study how the properties of water and the effect of its coupling with the hydrophilic moieties of proteins govern the regime of protein activity. In particular we follow, by means of Fourier Transform Infrared spectroscopy, the thermal evolution of the amides vibrational modes of hydrated lysozyme in the temperature interval 180K < T <350K. In such a way we are able to observe the thermal limit of biological activity characterizing hydrated lysozyme. Finally we focus on the region of lysozyme thermal denaturation by following the evolution of the proton Nuclear Magnetic Resonance (NMR) spectra for 298K < T <366K with the High-Resolution Magic Angle Spinning probe. Our data suggest that the hydrogen bond coupling between hydration water and protein hydrophilic groups is crucial in triggering the main mechanisms that define the enzymatic activity of proteins.

Source: Computational and Structural Biotechnology Journal - November 15, 2014 Category: Biotechnology Source Type: research