Figure 2

SDS-PAGE analyses of native and acid pH- or proteolytic enzyme-treated GII.4 VLPs. A. GII.4 VLPs after exposure to different acid pH conditions (7.4, 1.3, 2.0, and 3.0). B. GII.4 VLPs after exposure to 1,500 units/mL pepsin at pH 2.0. C. GII.4 VLPs after exposure to 0.1 mg/mL trypsin at pH 8.0. D. GII.4 VLPs after exposure to 100 mg/mL trypsin at pH 8.0. E. GII.4 VLPs after exposure to 0.1 mg/mL chymotrypsin at pH 8.0. F. GII.4 VLPs after exposure to 100 mg/mL chymotrypsin at pH 8.0. The term “Pre-heated” means that the VLPs were previously heated at 95 °C for 10 min to obtain VP1 prior to proteolytic enzyme treatments. The term “Heating at 95 °C” means that the VLPs or VP1 were heated at 95 °C for 10 min prior to SDS-PAGE analysis, to dissociate VLPs and remove secondary VP1 structures. The “ + ” and “-” signs indicate whether or not the treatment was applied. No sign means that there were no VLPs present. White spaces indicate the different parts of the same gels. Each condition was tested in triplicate.