University of New Hampshire
Mentor: Dr. Thomas M. Laue, UNH Department of Molecular, Cellular and Biomedical Sciences
The Charge on Beta-Lactoglobulin A and B under Self-associating Conditions
β-Lactoglobulin (β-LG) is a major whey protein abundant in cow milk. It has several genetic variants, is stable and self-associates under well characterized conditions. These factors make β-LG a great model to be used in the study of net charge and self association. Net charge is suggested to be related to protein functionality. With a better understanding of net charge, protein functionality can be better understood. Thus the information obtained from this study can help improve the pharmaceutical industry, the food industry, and advance protein science. From previous studies, it had been shown that as ionic strength increased at pH 3, the structure of β-LG changed and more dimer were formed. The change in concentration of β-LG also contributed to the change in its structure. The two genetic variants that will be used in the study are β-LG A and B. In order to measure net charge the model protein will be analyzed at pH 3, in a range of salt concentrations and protein concentrations. The charge on β-LG will be measured using capillary electrophoresis and membrane confined electrophoresis. The analytical ultracentrifuge will be used to observe self-association of β-LG. The obtained net charges will be compared with each other based on the conditions of ionic strength, concentration and stoichiometry.