FIG. 6.

SDS-PAGE of L. monocytogenes secreted and membrane-anchored proteins produced in LB broth. Wild-type L. monocytogenes 10403S was grown in buffered LB broth for 5.5 h, and secreted proteins (lanes 1 and 2) from 10 ml of culture were precipitated with trichloroacetic acid and resuspended in SDS-PAGE sample buffer. Membrane-anchored proteins (lanes 3 to 6) were extracted from bacterial pellets by boiling for 5 min in SDS-PAGE sample buffer. Eighty percent of each sample was subjected to SDS-PAGE, and the gel was stained with Coomassie brilliant blue. Lane 1, 10403S; lane 2, DP-L2161 (10403SΔhly) (14); lane 3, 10403S; lane 4, DP-L1942 (10403SΔactA) (3); lane 5, SLCC-5764 (5); lane 6, DP-L1955 (SLCC-5764ΔactA) (20). Arrows indicate the positions of LLO and ActA. Lanes M show molecular mass standards (kilodaltons [kd]).