Figure 4.

Correlations between in vitro properties of P454‐derived peptides and the internalization activity of the CyaA recombinant proteins. A) The free energy values of peptide:CaM complex formation (∆G _Kd) are plotted as a function of free energy values for peptide solution‐to‐membrane partitioning (∆G _Kx, see Table S3, Supporting Information) and permeabilization efficiency (Cp_1/2 values, see Table S9, Supporting Information). The color code refers to the Cp_1/2 values ranging from red‐to‐blue (high‐to‐low permeabilization efficiency, respectively) using a logarithmic scale (red: Cp_1/2 < 100 nM, orange: 0.1 < Cp_1/2 < 1 µm, green: 1 < Cp_1/2<10 µm, and blue: 10 < Cp_1/2 < 100 µm. B) The free energy values of peptide:CaM complex formation (∆G _Kd) as a function of relative internalization activity of the CyaA variants (data from Table 1). The peptide names are in black and the names of the recombinant CyaA proteins are in red, if different from the peptide name. Each dot reported on plots corresponds to the average value of at least three independent replicates (see Table 1; Tables S3 and S9, Supporting Information). The r² values for the data of panels (A) and (B) are 0.54 and 0.62, respectively.