The Hildebrand solubility parameters have been calculated for eight ionic liquids. Retention data from the inverse gas chromatography measurements of the activity coefficients at infinite dilution were used for the calculation. From the solubility parameters, the enthalpies of vaporization of ionic liquids were estimated. Results are compared with solubility parameters estimated by different me...

Melittin, a cationic hemolytic peptide, is intrinsically fluorescent due to the presence of a single functionally important tryptophan residue. We have previously shown that the sole tryptophan of melittin is localized in a motionally restricted environment in the membrane interface. We have monitored the effect of ionic strength on the organization and dynamics of membrane-bound melittin utili...

Colloidal stability of IgG antibody solutions is important for pharmaceutical and medicinal applications. Solution pH and ionic strength are two key factors that affect the colloidal stability of protein solutions. In this work, we use a method based on the PEG-induced liquid-liquid phase separation to examine the effects of pH and ionic strength on the colloidal stability of IgG solutions. We ...

A novel hydrogel film with a highly ordered macropore monolayer on its surface was prepared by templated photo-polymerization of hydrogel monomers on a two-dimensional (2D) polystyrene colloidal array. The 2D inverse opal hydrogel has prominent advantages over traditional three-dimensional (3D) inverse opal hydrogels. First, the formation of the 2D array template through a self-assembly method ...

The rapid binding of cytotoxic colicin E3 by its cognate immunity protein Im3 is essential in safeguarding the producing cell. The X-ray structure of the E3/Im3 complex shows that the Im3 molecule interfaces with both the C-terminal ribonuclease (RNase) domain and the N-terminal translocation domain of E3. The association and dissociation rates of the RNase domain and Im3 show drastically diffe...

We report direct measurements of entropic interactions of colloidal spheres in suspensions of rodlike fd bacteriophage. We investigate the influence of sphere size, rod concentration, and ionic strength on these interactions. Although the results compare favorably with a recent calculation, small discrepancies reveal entropic effects due to rod flexibility. At high salt concentrations, the pote...

The kinetics of the [Ni N,N'-bis(β-carbamoylethyl) ethylendiamine)]2+/Cu2+, Ni(bcen)2+/Cu2+ metal exchange reaction in aqueous solution has been studied using spectrophotometry to follow Cu(bcen)2+ formation at 640 nm (bcen is N,N'-bis(β-carbamoylethyl) ethylendiamine). The reaction was studied at pH 6.9, ionic strength 0.5 M and in the temperature range 15 to 35 °C. The kinetics was studied un...

The ionic strength of the medium plays an important role in the structure and conformation of erythroid spectrin. The spectrin dimer is a flexible rod at physiological ionic strength. However, lower ionic strength results in elongation and rigidification (stiffening) of spectrin as shown earlier by electron microscopy and hydrodynamic studies. The ionic strength induced structural transition do...

The equilibrium constant of the phosphoglyceromutase reaction was determined over a range of pH (5.4-7.9), in solutions of different ionic strength (0.06-0.3) and in the presence of Mg(2+), at 30 degrees C and at 20 degrees C. The values obtained (8.65-11.65) differ substantially from previously published values. The third acid dissociation constants were redetermined for 2- and 3-phosphoglycer...

The hemagglutination (HA) activity of two strains of Escherichia coli, each possessing different colonization factor antigens (CFA), was examined under different test conditions. The effects of ionic strength, temperature, pH, cations, and reaction surface on erythrocyte (RBC) agglutination were analyzed. Strain H-10407 (CFA/I) caused the agglutination of human, bovine, and chicken RBC, whereas...