FIG. 4.
Analysis of outer membrane proteins expressed by N. meningitidis FAM20 (wt) and its lpxA mutant L1. Outer membrane proteins were purified by the LiAc method for outer membrane bleb purification and separated by SDS-PAGE. Five proteins with altered expression levels in the lpxA mutant were subjected to amino-terminal sequencing. Asterisks, proteins with reduced levels in the LOS mutants; circles, proteins with increased amounts in the mutants. Identical results were obtained with outer membranes prepared by sarcosyl extraction. The same profiles were observed with the other eight mutants (L2 to L9; data not shown). Mw, molecular weight marker.