Figure 2.

CD spectra of (A) SBP1 and (C) SBP1^mod incubated in buffer (square) and with 10% (v/v, circle), 15% (up-triangle), 20% (down-triangle), 25% (rhombus), and 30% (star) 2,2,2-trifluoroethanol (TFE), respectively. 50 μM of each of these two peptides were incubated in 20 mM phosphate buffer with 150 mM NaF (pH 7.5) at 25°C. Spectra (in symbols) shown are the averages of five consecutive accumulations; they were fitted (solid lines) using the online version of the BeStSel software (21,22) for secondary structure determination. Variation of different secondary structures for SBP1 (B) and SBP1^mod (D) as a function of TFE concentration, showing helix (square), antiparallel (circle), parallel (up-triangle), turn (down-triangle), and others (rhombus). Solid lines are guide to the eye.