Thermal unfolding profiles of the Pitx2 homeodomain. Unfolded fractions of Pitx2 homeodomain wild-type and R24H plotted as a function of temperature. DNA free: wild-type (■), R24H (●). TAATCC bound: wild-type (▼), R24H (▲). Apparent Tm values for the wild-type free 42.0°C, R24H free 37/8°C, wild-type/TAATCC 58.5°C, R24H/TAATCC 54.2°C.