Figure 6

Protective secretion of OMV-associated A-LPS-modified PPAD. P. gingivalis was cultured in BHI and, subsequently, the cells and growth medium fractions were separated by centrifugation. Next, OMVs were collected from the growth medium fraction by ultracentrifugation, and part of the collected OMV fraction was subjected to sonication either in the absence (A,C) or presence (B) of protease inhibitors. Proteins from the growth medium fraction, intact OMVs and sonicated OMVs were separated by LDS-PAGE and analyzed by Western blotting using a PPAD-specific antibody (A,B) or an Omp41-specific antibody (C). Names of sorting type I isolates are underlined, and molecular weights of marker proteins are indicated. The full-length blots are presented in Figure S1. The band of 21 kDa labeled X represents an unidentified protein that cross-reacts with the Omp41-specific antibody, possibly a degradation product of Omp41.