Surface electrostatic interactions

Pattern recognition using cahxarene receptors that bind to proteins via surface electrostatic interaction has been used to identify a variety of proteins (Kolusheva et al. 2006). Amphiphilic calixarenes terminated with either amino or phosphate groups were incorporated into mixed PDA/phospholipid vesicles, which were incubated with various proteins that differed in their isoelectric points (pi). As expected, proteins with low pi values resulted in a large CR with liposomes containing cationic calixarene receptors. Each protein was characterized by a unique ACR value, where... 

The vast majority of work on particle-surface electrostatic interactions has neglected any effects due to particle motion. However, both theoretical [31,32] and experimental work [33-35] have been done on the problem of a charged particle interacting with a charged wall in a linear shear flow. In the theoretical treatment, it is assumed that the double layer thickness is small compared to both the particle diameter and the surface-to-particle gap. Hence, changes in the pressure and potential profiles in the gap caused by motion can be written as small perturbations to their equilibrium profiles. In the region outside the small double layers, the fluid velocity v and perturbation pressure dp are governed by Stokes equations... 

With respect to the molecular interactions the simplest asymmetric films are these from saturated hydrocarbons on a water surface. Electrostatic interaction is absent in them (or is negligible). Hence, of all possible interactions only the van der Waals molecular attraction forces (molecular component of disjoining pressure) can be considered in the explanation of the stability of these films. For films of thickness less than 15-20 nm, the retardation effect can be neglected and the disjoining pressure can be expressed with Eq. (3.76) where n = 3. When Hamaker s constants are negative the condition of stability is fulfilled within the whole range of thicknesses. 

The interpretation of Eq. [44] is suggested by the negative DPSA term. Decreased DPSA values mean decreased positively charged surface atom area as compared to negatively charged surface atom area. This could be associated with smaller (weaker) intermolecular surface electrostatic interactions which... 

We recently considered the effect of the nucleic acid-surface electrostatic interaction on the thermodynamics of the surface hybridization [2-5, 22], This theory used an analytical solution of the linearized Poisson-Boltzmann boundary value problem for a charged sphere-surface interaction in electrolyte solution and corresponds to the system characterized by a low surface density of immobilized probes. To understand the motivation for that work and extensions, we need to consider the physical effects of a surface in solution and the theoretical tools available for their study. 

Sali D, Bycroft M, Fersht AR (1991) Surface electrostatic interactions contribute little of stability of bamase. J Mol Biol 220(3) 779-788... 

In Equations 11.30,11.31, and 11.37, the intrinsic binding constants A) are true thermodynamic quantities, related to the free energy by Equation 11.3. However, when aqueous ion activities are replaced by concentrations and the ionic strength (and/or pH and/or other concentrations) is kept constant, or when (more frequently) surface electrostatic interactions are neglected, results for the binding constants can be found, but which are valid only in the same experimental conditions as the original data these are called conditional affinity spectra or conditional constants, a concept widely used in analytical chemistry (Garces, Mas, and Puy 2006 Orsetti, Andrade, and Molina 2009). Numerical methods for affinity spectrum extraction almost always yield conditional spectra. 

In summary, the findings of this study are in general agreement with the conclusions from many other published studies regarding the meehanisms behind the protein resistance of PEGylated surfaces. Electrostatic interactions are clearly... 

In the limit of strong adsorption, the polyelectrolyte adsorption energy is large compared to the thermal fluctuations of the polymer chain. Hence, the structural properties of adsorbed chains are essentially governed by maximization of polyelectrolyte-surface electrostatic interactions and minimization of polyelectrolyte-polyelectrolyte repulsion [59]. Therefore, we consider a polyelectrolyte chain... 

Due to low water contents, high specific surface areas and pore structures (see the previous section), the water-rock interactions within the Tournemire shales must be characterized by strong short range (nanometre-scale) water (or solute) molecules-mineral interactions. Therefore, the physico-chemical characteristics of the water and its solutes will be different from that of free water which is conventionally considered to take part in water-rock interactions (Horseman et al. 1996). The difference arises from factors such as the very low mobility of water in thin films, the high suction potentials developed owing to water-mineral surface electrostatic interactions and the membrane filtration of anions. The 9% porosity given above must be considered as a maximum value since waters bound chemically to mineral surfaces are included in the estimates in reality free waters are of most importance to the present study. 

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