[Study of the effect of temperature on the conformation of ovotransferrin by two-dimensional infrared correlation spectroscopy].

The conformation changes of Apo-Ovotransferrin and Holo-Ovotransferrin were studied with the heat treatment 25~95 ℃ by using Fourier transform infrared spectroscopy(FTIR) and two-dimensional correlation spectroscopy analyzer.The results of one-dimensional infrared spectroscopy showed that with the increase in temperature,the peak at 3 300 cm-1 of Apo-Ovotransferrin shifted more than that of Holo-Ovotransferrin.The peak at 3 300 cm-1 derived from stretching vibrations of N—H and O—H indicates that iron-binding enhanced the role of hydrogen bonds and resistance to heat.The changing order of the secondary structure of ovotransferrin was determined by analyzing two-dimensional infrared spectra,witch is β-sheetamideⅡ—CH2— bending vibration.In addition,it was found that the cross-peaks at 1 652 and 1 688 cm-1 are different in synchronous and asynchronous counter maps by comparing Apo-Ovotransferrin with Holo-Ovotransferrin.It was suggested that the temperature made less impact on the α-helix in Holo-Ovotransferrin than on that in Apo-Ovotransferrin,however,the β-turn in Holo-Ovotransferrin was more sensitive to temperature.