Protein solubility
The protein solubility versus pH profile was generated by following the method of Hojilla-Evangelista, Evangelista, and Wu (2009), which used sample dispersions having 10 mg protein/mL with their pH adjusted to 2.0, 4.0, 5.5, 7.0, 8.5, and 10.0. Soluble protein in the supernatant was determined by the Biuret method using BSA for the standard curve.