Abstract
We have investigated low temperature-induced secondary structural changes of polypeptide and helical rich proteins using FTIR and CD spectroscopies. It is found that the low-temperature crystallization induces the increase of the solvated α-helical structure, which is due from the hydration between the α-helix structure and water molecules, of polypeptide and helical-rich proteins. The α-helical structures of polypeptide and helical-rich proteins did not unfold in spite of the ice formation in bulk water. Our results suggest that helical proteins may have the possibility of self-depression function to the low temperature-induced protein unfolding.
