Figure 2. Analyses of the ability of CSP1 analogs to induce comX expression and genetic transformation.

Pneumococcal cells were incubated with CSP1 or with each analog at a final concentration of 100 ng/ml. The ability of each peptide to induce the competence regulon was measured by induction of the comX expression using the ß-galactosidase assays in D39pcomX::lacZ cells (A) or by genetic transformation using the rpsL gene in D39 cells (B). Transformants were selected on THB agar containing 100 µg/ml streptomycin. Experiments were performed in triplicates and repeated three times. The means ± SD of one typical experiment are shown.