Table 1. Midpoint denaturation temperatures (T_m1 and T_m2) for the melting transitions of hArc, measured by thermal-dependent CD and derivatization of the transitions.

hArc (4.4 μM) was prepared in 10 mM potassium phosphate at the indicated pH and conditions.

Condition	Tm1 (°C)	Tm2 (°C)
pH 6.3	43.2±0.9	75.0±0.6
pH 7.4	46.4±1.1	74.3±0.2
pH 8.2	48.5±0.1	73.8±1.0
pH 7.4, 150 mM KF	43.0±0.2	75.8±1.5
pH 7.4, 300 mM KF	42.7±0.4	77.6±0.1
pH 7.4, 5 μg/ml heparin	53.0±0.8	73.9±0.5
pH 7.4, 20 μM calcium	46.5±0.9	74.3±0.5