Fig. 7: Bacillaene inhibits CsgA amyloidogenesis in vitro.

a, b Bacillaene prevents accumulation of insoluble CsgA amyloid fibers in vitro. Purified CsgA was allowed to polymerize for 16 h in the presence or absence of bacillaene or extract from the pksL mutant without (a) or with (b) supplementation of CR. CsgA polymerizes forming insoluble and CR-stainable amyloid fibers that accumulate and precipitate. Such polymerization is abolished in the presence of bacillaene. c SEM image showing the dense network of amyloid fibers that results from the polymerization of purified CsgA in vitro as indicated in (a). d Bacillaene inhibits the polymerization of CsgA in vitro in a dose-dependent manner. The kinetics of accumulation of CsgA fibers in the presence/absence of bacillaene o the pksL extract (at different concentrations/volumes) was monitored by measuring the optical density at 578 nm. Volumes indicated correspond to a 700 μg/ml solution of purified bacillaene or to pksL extract. Bacillaene concentrations indicated in parentheses are final concentrations (fc) in wells. The graph shows representative data sets of at least three replicates performed for each experiment with similar results.