Table 1.

McDCM parameters used in this study^∗

Parameter	Physical interpretation	A4 Y(AEARA)4Nres = 21	V5† Y(XEARA)6Nres = 31	A6 Y(AEARA)6Nres = 31	Peptide I Ac-Y(AEAAKA)8F Nres = 50
ɛHB	H-bond energy	−0.83	−0.83	−0.60	−1.14
ɛNT	Native torsion force energy	−0.50	−0.40	−0.45	−0.09
γHB	H-bond pure entropy cost	1.19	1.13	1.07	0.94
γNT	Native torsion force pure entropy cost	0.75	0.75	0.90	0.35

^∗Values were determined by fitting to the DSC data in Richardson and Makhatadze (29) for A4, V5, A6, and Scholtz et al. (30) for peptide I. The fits are shown in Fig. 3. The units of the energy parameters are kcal/mol, and the entropy parameters are unitless.

^†In the V5 polypeptide, X = A in repeats 1–4 and 6, whereas X = V in the fifth repeat.