Preferential interaction

Timasheff, S.N. (1982). Preferential interactions in protein-water-cosolvent systems. In Biophysics of Water, ed. F. Franks, pp. 70-2. London John Wiley. 

A thiol-terminated PS was used as a sample in the experiment. It was based on a living polymerized carboxyl-terminated PS with M = 93,800 and Mu = 100,400. The polydispersity was Mp( /M = 1.07. The degree of polymerization was about 900 and, thus, its contour length was about 220 nm. The thiol groups were substimted for the carboxylic ends using 1,10-decanedithiol by means of thiolester bonding, anticipating the preferential interaction between... 

In this work a new approach is desribed, which can help to understand ED over heterogeneous catalysts We also hope that this approach can be used to find new modifiers for enantioselective heterogeneous catalytic reactions. The basis for this approach is the steric shielding known in organic chemistry [7,8]. A chiral template molecule can induce shielding effect (SE) in such a way that it preferentially interacts with one of the prochiral sites of the substrate. If a substrate is preferentially shielded its further reaction can take place only fi"om its unshielded site resulting in ED. 

Separations in hydrophobic interaction chromatography have been modeled as a function of the ionic strength of the buffer and of the hydrophobicity of the column, and tested using the elution of lysozyme and ovalbumin from octyl-, butyl- and phenyl-Sepharose phases.2 The theoretical framework used preferential interaction analysis, a theory competitive to solvophobic theory. Solvophobic theory views protein-surface interaction as a two-step process. In this model, the protein appears in a cavity in the water formed above the adsorption site and then adsorbs to the phase, with the free energy change... 

Nucleophiles preferentially interact with triafulvenes by attack at the three-ring carbons, as shown by reactions with water, alcohols, ammonia, and other N- and C-nucleophiles. 

Figure 10. View of cytochrome c with positions of exposed heme edge (block) and lysine modifications (sequence numbers for a-carbons) shown. The smaller circles indicate the relative effectiveness of modifications on rate constants for the reaction of Cyt c(II) + PCu(II) ( see Table III). Preferential interaction with PCu(II) in the direction 25,27,13,87 is indicated.

ErbB (or HER in the human). There are four ErbB receptors that form homo- or heterodimers in various combinations upon ligand binding. Specific NRG isoforms preferentially interact with different ErbB dimers. The ErbB receptors are ligand-activated tyrosine kinases structurally similar to the EGF receptor. 

The ionic strength of the solution also significantly influences polyelectrolyte adsorption. In general, the higher the ionic strength of the medium, the less extended and the more coiled the polymer conformation becomes (due to preferential interaction with counter ions in solution rather than with other segments of the polymer chain). The coiled polymer becomes more accessible to the internal porous structure and adsorption is increased. However, for the same reason, it is less influential on the surface charge. 

Some practical applications of non-covalent interactions are also very interesting. The basis of the separation of enantiomers by the chromatographic method21 is the preferential interaction of one enantiomer of a substance with one enantiomer of another substance, which is usually part of the chiral stationary phase. Non-covalent interactions are more frequent hydrogen bonding, host-guest and donor-acceptor interactions. 

The quality of the thin film depends on preferential interactions between precursor and coating substrate. However, the initial layer is clearly the most important and, in the case of nanocarbons, the surface chemistry must be tailored. For most ALD precursors, hydrophilic surface groups enhance deposition, which can be achieved by functionalizing the nanocarbon prior to placement in the ALD reaction chamber or by treating the sample within the chamber with reactive plasma. Among the many in situ hybridization techniques, ALD provides best control of thin film thickness. 

The first family of the so-called anion receptors was aza-ethers that were based on cyclic or linear amides, where the nitrogen core was made electron-deficient by the perfluoroalkylsulfonyl substituents so that these amides would preferentially interact with the electron-rich anions through Coulombic attraction, contrary to how their unsubstituted counterparts would act. Two selected representatives from the aza-ether family are shown in Table 8. When used as additives in solutions of various lithium halides LiX in THF, these novel compounds were found to increase both the solubility and the ion conductivity of these solutions. For example, the ion conductivity of the LiCl/THF solution was 0.0016 mS cm while the LiCl/THF solution with one of the linear aza-ethers containing eight perfluoroalkylsulfonyl substituents n = 5 for the linear aza-ether shown in... 

Angelov, D., Vitolo, J.M., Mutskov, V., Dimitrov, S., and Hayes, J.J. (2001) Preferential interaction of the core histone tail domains with linker DNA. Proc. Natl. Acad. Sci. USA 98, 6599-6604. Tobias, I., Coleman, B.D., and Olson, W. (1994) The dependence of DNA tertiary structure on end conditions theory and implications for topological transitions. J. Chem. Phys. 101, 10990-10996. Coleman, B.D., Tobias, I., and Swigon, D. (1995) Theory of the influence of end conditions on selfcontact in DNA loops. J. Chem. Phys. 103, 9101-9109. 

The nucleosome core particle is a relatively stable and homogenous structure that is easily prepared, and as such has formed the basis for numerous studies into chromatin structure and function. However, several recent studies have suggested that what is true for the nucleosome core may not always be true for nucleosome arrays, nor even for nucleosomes containing linker DNA. For example, the core histone tails preferentially interact with linker DNA when is it present, whereas they are constrained to bind intranucleosomal DNA in core particles [46 8]. Consequently, the activities of proteins that require access to the tails or the DNA may be affected, and it has been shown that both DNA ligase and P/CAF are less active on nucleosome core particles than other chromatin substrates [49,50]. Similar concerns apply to the interaction of HMGN proteins with nucleosome core particles, and results from studies of these complexes must be considered in the wider context of how these proteins may interact with nucleosome arrays. 

In the development of various equilibrium expressions, it was assumed implicitly that every internal energy state of the reactants (A + B) would have an equal probability of interacting on the particular Bom-Oppenheimer PES relevant to the chemical process of interest. The work described here clearly demonstrates that the validity of such an assumption can depend directly on symmetry considerations. Indeed, it is the propensity of reactants in motional states of a particular symmetry to preferentially interact on a Bom-Oppenheimer PES of a complementary symmetry when identical nuclei are present that is at the heart of the present theoretical description of SIKIE. 

Interfacial agent comprised of molecules possessing two or more functional groups, each of which exhibits preferential interactions with the various types of phase domains in a... 

MD simulations have provided a unique molecular description of cholesterol-phospholipid interactions [31]. Atomistic simulations have succeeded in reproducing the condensing effect of cholesterol on phospholipid bilayers [32-34], With atomistic detail, many properties can be determined, such as the effect of cholesterol on lipid chain ordering or on hydrogen bond formation. Other simulations have focused on the interaction of cholesterol and SM [35-37], Aittoniemi et al. [38] showed that hydrogen bonding alone cannot explain the preferential interaction between cholesterol and SM compared to cholesterol and POPC. 

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