Figure 4.

Temperature dependence of folding for trpzips 4–6 (calculated from the thermodynamic parameters listed in Table 2). Our estimated curve for gb1 was calculated by assuming that mutations in trpzip4 (i.e., those present in trpzips 5 and 6) have independent and additive effects on hairpin stability [ΔG_unf,gb1 = ΔG_unf,trpzip5 − (ΔG_unf,trpzip4 − ΔG_{unf, trpzip6})] (12) and is nearly identical in shape to previously reported gb1 denaturation curves based on fluorescence (7) or NMR (8) measurements. However, our estimated population for the folded conformation of gb1 is much closer to that in the original report (28) than to later estimates (7, 8).