磷脂酰胆碱与牛血清白蛋白相互作用的FT-IR研究

利用傅立叶变换红外(FT-IR)和拉曼(FT-Raman)光谱研究了高浓度磷脂酰胆碱(PC)与牛血清白蛋白(BSA)的相互作用,及Eu3＋对该作用的影响.FT-IR结果显示,PC/BSA混合体系中二者的相互作用主要发生在PC头部极性基团,且这一作用随BSA含量的增加而增强,作用后蛋白质二级结构中α螺旋的比例有所增加. FT-Raman光谱说明PC与BSA的相互作用影响磷脂CH链的排列有序程度. PC/BSA/Eu3＋体系的红外光谱显示, Eu3＋与PC的磷氧键发生了强相互作用,并使蛋白α螺旋的比例进一步增加.

FT-IR Study of the Interaction between Phosphatidylcholine and Bovine Serum Albumin

The interactions between phosphatidylcholine (PC) and bovine serum albumin (BSA) were studied by FT-IR and FT-Raman spectroscopies, then the influence of lanthanide ion Eu3＋ on the PC/BSA mixture system was discussed. In the region of 900～1300 cm－1, FT-IR spectra showed that the bands of P=O, P-O-C and C－O of the PC/BSA mixture were shifted compared with the corresponding bands of pure PC and BSA, and the more content of BSA (relative to the content of PC) the greater shift was observed. The curve-fitting result of amide I band indicated that an increase of α-helix fragments in the PC/BSA mixture. FT-Raman spectra showed that the CH stretching bands in the PC/BSA mixture were varied, which indicated a disturbance of PC′s long chains in the mixture system. After Eu ion was added into the PC/BSA system, the P=O stretching vibration bands in FT-IR spectra shifted from 1241 to 1208 cm－1. This helped us to conclude that the Eu ions bind to the P=O group in the PC/BSA mixture.