Table 1.

Properties of de novo proteins

Protein	Mass (Obs)	Mass (calc)	Elution time (min)	CD (222 nm)	Gnd-midpoint	ΔG (kcal/mole)
n86	8625.9	8627.7	nd	−21,950	1.7 M	3.0
S-23	11856.0	11855.2	23.35	−25,890	3.7 M	6.6
S-213	11857.0	11856.3	23.35	−29,690	3.4 M	8.4
S-285	12063.2	12062.5	23.79	−32,870	3.6 M	9.5
S-824	11928.8	11928.4	23.77	−29,710	3.2 M	7.7
S-836	11927.7	11927.4	23.76	−31,550	3.0 M	5.4
cyt C		12384	22.60

Mass (obs) was measured using electrospray mass spectrometry. Mass (calc) was calculated from the sequences. Elution times were measured using size-exclusion chromatography performed at the same concentrations as NMR experiments. CD (222 nm) indicates mean residue ellipticity at 222 nm at 20°C. Gnd midpoint is the concentration of guanidine hydrochloride at which 50% of the protein sample is denatured. ΔG indicates the free energy of unfolding in the absence of denaturant, and is derived by extrapolation of the guanidine denaturation data.