Ren Guo-Dong, Guo Ai-Ling, Geng Fang, Ma Mei-Hu, Huang Qun, Wu Xiao-Fen
National Research and Development Center for Egg Processing, Huazhong Agricultural University, Wuhan 430070, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2012 Jul;32(7):1780-4.
The conformation changes of Apo-Ovotransferrin and Holo-Ovotransferrin were studied with the heat treatment 25-95 degrees C 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-Ovo-transferrin 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 beta-sheet>amide II >-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 alpha-helix in Holo-Ovotransferrin than on that in Apo-Ovotransferrin, however, the beta-turn in Holo-Ovotransferrin was more sensitive to temperature.
利用傅里叶变换红外光谱（FTIR）和二维相关光谱分析仪，研究了25至95摄氏度热处理条件下脱铁转铁蛋白和全铁转铁蛋白的构象变化。一维红外光谱结果表明，随着温度升高，脱铁转铁蛋白在3300 cm⁻¹处的峰比全铁转铁蛋白的峰移动得更多。3300 cm⁻¹处的峰源于N-H和O-H的伸缩振动，这表明铁结合增强了氢键作用和耐热性。通过分析二维红外光谱确定了转铁蛋白二级结构的变化顺序，即β-折叠>酰胺II>-CH₂-弯曲振动。此外，通过比较脱铁转铁蛋白和全铁转铁蛋白发现，在同步和异步对映图中，1652和1688 cm⁻¹处的交叉峰不同。结果表明，温度对全铁转铁蛋白中α-螺旋的影响小于对脱铁转铁蛋白中α-螺旋的影响，然而，全铁转铁蛋白中的β-转角对温度更敏感。
