On the cold denaturation of globular proteins

The recent finding that yeast frataxin shows, at pH 7.0, cold denaturation at 274 K and hot denaturation at 303 K [A. Pastore, S.R. Martin, A. Politou, K.C. Kondapalli, T. Stemmler, P.A. Temussi, J. Am. Chem. Soc. 129 (2007) 5374] calls for a deeper rationalization of the molecular mechanisms stabilizing–destabilizing the native state of globular proteins. It is shown that the statistical thermodynamic model originally developed by Ikegami can reproduce in a more-than-qualitative manner the two conformational transitions of yeast frataxin, providing important clues on their molecular origin.