Microcalorimetry of thermal denaturation of pepsin and trypsin in the crystal state.

Heating of pepsin and trypsin crystals was studied by scanning microcalorimetry. A sharp decrease in temperature, halfwidth and heat of transition with a decrease in heating rate was discovered. It was shown that thermal transition is connected only with the denaturation of protein molecules in the crystal and not accompanied by the crystal disintegration into separate molecules.