3.5. Size-Exclusion Chromatography and Polyacrylamide Gel Electrophoresis

Fast protein liquid chromatography (FPLC; Bio-Rad, USA) was performed using an Enrich size-exclusion chromatography (SEC) 650 column equilibrated with 50 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (pH 7.4) buffer at a flow rate of 0.5 mL/min at 25 °C. Protein fraction peaks (A280) were isolated and concentrated using a Centricon YM-10 unit (Millipore Co., Santa Clara, USA) [29,30]. Protein fractions obtained from the first SEC run were concentrated and stored at 4 °C until the second SEC was performed. SDS- and native-PAGE was performed using previously reported methods [28,30].