FIG. 4.

SDS-PAGE of the 40-kDa MOMP of V. anguillarum O2 at different stages of purification. Lanes: 1, sarcosine-insoluble outer membrane protein pellet; 2, SDOC-soluble extract of the outer membrane protein pellet; 3, SDOC-insoluble outer membrane protein; 4 and 5, supernatant and insoluble pellet, respectively, obtained from a second extraction of the insoluble outer membrane protein with SODC buffer; 6, NaCl-SDOC-insoluble outer membrane protein; 7, NaCl-SDOC-soluble 40-kDa MOMP. Protein samples were treated at 100°C for 10 min in sample buffer, and 20 μg of protein was loaded in lanes 1, 3, 5, 6, and 7. Lanes 2 and 4 contained the maximum volume of sample that could be loaded in each lane. Molecular mass standards are indicated on the left. The MOMP is indicated on the right.