A study of the thermal denaturation of ribonuclease by differential scanning calorimetry
Delben, F.; Crescenzi, V.; Quadrifoglio, F.
International Journal of Protein Research 1(3): 145-149
A study by differential scanning calorimetry (DSC) of ribonuclease thermal denaturation in water, 1.5, 2.5, and 4M aqueous urea, and in 1M and 2M aqueous hexame-thylenetetramine has been carried out. Application of the Dsc technique to this type of investigation appears a useful one, in our experience. Our results indicate that whereas urea only slightly changes enthalpy variation accompanying denaturation but lowers the melting temperature of ribonuclease, hexamethylenetetramine does not effect either factor. According to these results, which are beyond experimental errors, the ability of hexamethylenetetramine in influencing hydrophobic-forces-driven phenomena (Barone, Crescenzi & Quadrifoglio 1967) has thus apparently no counterpart in any important action of this compound on the stability of a partially hydrophobic protein in aqueous solution.