Thermodynamic parameters for the disorder ↔ α-helix transition within the MBP α2-peptides in aqueous conditions.

Thermodynamic values were determined at 25°C from fitting CD-monitored TFE-titration curves to a 2-state transition (disordered↔α-helical). All errors (±) are standard deviations from at least three independent experiments.a[TFE]mid was determined from data fitting and represents the [TFE] at the mid-point of the transition (i.e., [TFE] when half the peptide molecules contain an α-helical conformation).bΔ[TFE]mid = [TFE]mid (phosphorylated peptide)−[TFE]mid (unmodified peptide).cΔGH2O is the change in free energy of the transition calculated as ΔGH2O = [TFE]mid•m; where m is the dependence of ΔG on [TFE], determined directly by independently fitting all titration curves (both modified and phosphorylated) and averaging to yield a value of 6.5±0.7 kJ mole−1 M−1.dΔΔGH2O = ΔGH2O (phosphorylated peptide) − ΔGH2O (unmodified peptide).en.a, not applicable.