Water-mediated ordering

Acharya H, Ranganathan S, Jamadagni SN, Garde S (2010) Mapping hydrophobicity at the nanoscale applications to heterogeneous surfaces and proteins. Faraday Discuss 146 353 Bratko D, Daub CD, Luzar A (2009) Water-mediated ordering of nanoparticles in an electric field. Faraday Discuss 141 55-66... 

Roberts et al. (1993) have provided an in-depth analysis of QSARs for dehydrohalogenation reactions of polychlorinated and polybrominated alkanes. The QSARs were developed based on a dataset of 28 polychlorinated and polybrominated compounds in aqueous solution at 25° C. The QSARs are for the OH- and water-mediated second-order elimination reactions (E2), as Equation (25) shows. The first QSAR is for base-promoted dehydrochlorination and is based on the inductive parameter o, (Equations (26) and (27)) ... 

Once dioxygen arrives at a cell it is reduced to water in order to yield the energy necessary to convert adenosine diphosphate (ADP) to adenosine triphosphate (ATP), the energy carrier for cell processes. This oxygen burning (8.1) is mediated in turn by a series of metalloenzymes, such as cytochrome oxidase, which contains one heme Fe and one Cu in the active site. 

Boimd to 1, the intercalated bithiazole is positioned with its C-terminal thiazole ring sandwiched between Aio and An while the N-terminal thiazole occupies a more central position between the base pairs involving these same residues the helix is unwound by 8.9. In this position, the guanidinium tail is threaded through to the major groove and forms a water-mediated H-bond to the N7 of Aio. Connected to the bithiazole, the Thr-methylvalerate linker is well ordered and makes two specific H-bonds to the sugar-phosphate backbone these interactions include the methyl valerate hydroxyl group to the 03 of T6 and the bithiazole NH (amide link to Thr) to the 04 of T7. 

For example, in the trp repressor-DNA complex there are only a few direct contacts between the protein and the base-pairs [6]. It is interesting to note here that three ordered water molecules are found at the protein-DNA interface that are hydrogen-bonded with both the base pairs and the protein side-chain atoms. These water-mediated bases are among the most important parts in controlling the repressor s affinity for the operator sequence in the DNA. 

Cationic phosphine ligands containing guanidiniumphenyl moieties were originally developed in order to make use of their pronounced solubility in water [72, 73]. They were shown to form active catalytic systems in Pd-mediated C-C coupling reactions between aryl iodides and alkynes (Castro-Stephens-Sonogashira reaction) [72, 74] and Rh-catalyzed hydroformylation of olefins in aqueous two-phase systems [75]. 

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