FIGURE 5.

Increase in peptide α-helix conformation, ΔX_α, (determined with CD spectroscopy) as a function of surfactant headgroup size, for β-C₁₂G_X surfactants (▴) and C₁₂E_X surfactants (♦). A (KF)_n concentration of 25 μg/ml (which equals 0.14 mM of amino acid residues) was used, and the measurements were performed in a 20-mM acetate buffer at pH 4.9. Since the Krafft point of β-C₁₂G₁ is above room temperature, it cannot be used for comparison. The glucosides are therefore represented by β-C₉G₁. The data points represent the mean value from at least three independent measurements, and the error bars correspond to 1 SD.