Figure 9

Influence of selective gene disruptions on G27 LPS response to cholesterol availability. In each experiment, parallel cultures of genetically altered G27 strains were grown overnight in defined medium without (-) or with (+) 50 μg/ml cholesterol. Cell lysates were adjusted to equal protein content, digested with proteinase K, and resolved on a 15% urea gel as described in Methods. Sample amounts loaded per lane correspond to 2 μg of cellular protein. Reference lanes contain 400 ng of purified LPS from E. coli strain O111:B4. A. LPS preparations from pairwise minus- and plus-cholesterol cultures of two individual cgt::cat G27 transformants. B. LPS from pairwise cultures of the O-chain-lacking pmi::cat G27 strain. C. LPS from pairwise cultures of wild type G27, or of isogenic lpxE::cat or eptA::cat strains.