Protein structure and function are determined by amino acid sequences. Amino acid sequences also determine protein charge states.
We mesured the electrophoretic mobility of acidic proteins using an electrophoretic light scattering photometer to obtain zeta potential. The proteins examined were bovine serum albumin (monometer, Mw = 66,000), ovalbumin (Mw = 45,000), and ß-lactoglobulin B (Mw = 18,000) obtained from Sigma-Aldrich. We prepared samples using a 10 mM phosphate buffer solution (pH 7) at protein concentration of 1 mg/ml and filtrated them through a 0.1 µm filter. Measurements were made at 25oC and zeta potential calculated using the Smoluchowski equation.
