Kresheck, Gordon C.
M.S. (Master of Science)
Department of Chemistry
Chemical bonds; Cations; Thermodynamics
This research project studied the heat of binding of divalent cations to sonicated asolectin vesicles under varying conditions of concentration, temperature and ionic strength. The vesicles were prepared by dissolving asolectin into Tris buffer and dialyzing the mixture. Exhaustive dialysis was performed to remove the ash content. After dialyzing, the mixture was sonicated and stored at 2° C. The divalent cations were made by dissolving the chloride salts of calcium and magnesium with no other preparations. Vesicle concentration was determined by measuring the inorganic phosphate content using a modified Fiske and Subarrow method. Measurements were made on a titration calorimeter. A method referred to as the "slope method" was used to analyze the titration curves. The theoretical bases and experimental validation of the method is provided along with its practical application. The results showed the heat of binding was dependent upon divalent cation, ionic strength, temperature and concentration of cation. The heat of binding was drastically lowered in an ionic environment showing the decrease of cation affinity to vesicles. Also, the heat of binding for magnesium was about half the value for calcium cations. The temperature study showed that the heat of binding had a dependency on temperature that was non-linear. The concentration of cation study showed a linear increase as a cation concentration is lowered. Extrapolating to infinite dilution gave a heat of binding for calcium ions to vesicles of -5400 cal/mol
Vallone, Michael, "Thermodynamics of bivalent cation binding to asolectin vesicles" (1982). Graduate Research Theses & Dissertations. 6438.
xi, 174 pages
Northern Illinois University
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