Thermal denaturation curves for imiglucerase and N370S GCase as measured by DSC. Excess molar heat capacity (kcal mol−1 °C−1) plotted against temperature (°C) from 35 to 70 °C for 16 μm samples in 0.1 m citrate/phosphate buffer, imiglucerase, pH 5.4 (solid line), rGCR, pH 7.1 (dashed line), N370S, pH 5.4 (dash dot dot line) and N370S, pH 7.1 (dotted line).