Hydrogen protein-water

Hydrogen production, water-splitting photosynthesis, semiarteficial system, His-tagged membrane proteins, photosystem 1, photosystem 2... 

The hydroxyl of Thr-113 forms a hydrogen bond to the carbox-ylate of Asp-27 and interacts with the 2-amino group of the pteridine moiety through a hydrogen-bonded water. Its replacement, in eDHFR, by Val decreases the binding of dihydrofolate 25-fold and causes a destabilization of the protein. In ADHFR, this residue is replaced by Ser, which, like Thr, can participate in the hydrogen bonding. 

In this study [15,29], we have carried out the 3D-RISM calculation for a hen egg-white lysozyme immersed in water and obtained the 3D-distribution function of oxygen and hydrogen of water molecules around and inside the protein. The native 3D structure of the protein is taken from the protein data bank (PDB). The protein is known to have a cavity composed of the residues from Y53 to 158 and from A82 to S91, in which four water molecules have been determined by means of the X-ray diffraction measurement [30]. In our calculation, those water molecules are not included explicitly. 

Hydration water molecules indicate substrate-binding sites. In crystal structures of native proteins, the active sites are usually hydrated if they are not in direct contact with symmetry-related protein molecules. Since the substrates or inhibitors are recognized by the protein and bound to its active site by hydrogen bonds and/or by insertion of hydrophobic residues into hydrophobic pockets, it is not surprising to find, in the native protein, water associated in positions which are the... 

One can picture the percolation process detected in the dielectric response as proton transfer along a thread of hydrogen-bonded water molecules adsorbed on the protein surface (Careri et al., 1986). The water molecules are formally equivalent to the conducting elements of the familiar percolation model of a conducting network. Above the thresh-... 

Threads, clusters, or networks of water molecules have been detected by crystallographic, thermodynamic, and dynamic measurements. They appear to be a common feature of the protein—water interface, which should not be surprising, in view of the extensive hydrogen bonding of the bulk water. Moreover, the water of the interface differs from... 

In their native conformation, globular proteins have non-polar amino acid side chains oriented towards the interior of the protein and polar side chains oriented outwards, towards the solvent. The stability of the native conformation is determined by hydrophobic interactions within the interior of the molecule, and electrostatic interactions and hydrogen bond interactions at the protein-water interface. Disturbing these interactions can alter the balance between the intra- and intermole-cular interactions, which are responsible for maintaining the protein in soluble... 

A series of hydrogen-bonded water molecules and protein groups that can... 

Another important aspect of the structure of proteins is the presence of hydrogen-bonded water... 

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