FIG. 5.
(A) Western blot analysis of NMB1869 and fHBP protein expression in a broad panel of 40 N. meningitidis strains. Whole bacterial lysates were prepared from overnight plate cultures and subjected to immunoblot analysis with mouse polyclonal antibody against each protein. The asterisk marks a nonspecific cross-reactive band that is shown as a loading control. The fHBP protein is expressed at different levels in different strains. In this representative Western blot, it is not possible to visualize fHBP expression in some of the isolates (M2671, 5/99, OX99.30304, M1239) due to their low level of expression that was evident only with long exposure of the film (data not shown). (B) Western blot analysis of protein expression on a subset of wild-type strains and their respective FNR mutant derivative expressing the FNR(D148A) protein (+). The site-directed mutant allele of the fnr gene, fnr(D148A), was inserted under the control of the Ptac-inducible promoter in the genomes of these strains, and FNR expression is induced by growth on 1 mM IPTG. Immunoblot analysis was performed using antisera against NMB1869, fHBP, and the FNR protein. N, Norway; UK, United Kingdom; USA, United States; TCH, Chad; F, Finland; D, Denmark; NL, the Netherlands; RUS, Russia.