FIGURE 4.

Thermotropism of CerIII/PA-d₃₁/sterol (1:1:1) mixtures, as probed by the I₂₈₈₀/I₂₈₅₀ intensity ratios (▪) and the Δν_CD (○) obtained from Raman spectroscopy. (A) CerIII/PA-d₃₁/chol (1:1:1) mixtures free of Ca²⁺. (B) CerIII/PA-d₃₁/chol (1:1:1) mixtures with 100 mM Ca²⁺. (C) CerIII/PA-d₃₁/CS (1:1:1) mixtures free of Ca²⁺. (D) CerIII/PA-d₃₁/CS (1:1:1) mixtures with 100 mM Ca²⁺. The two y-scales were adjusted such that a gel-to-liquid crystalline phase transition of phospholipid bilayers is represented by a variation with the same amplitude for the two parameters. Note that the I₂₈₈₀/I₂₈₅₀ scale is upside down to allow the direct comparison with the Δν_CD variations.