金纳米粒子与抗体蛋白相互作用的光谱研究  

Spectroscopic Investigation of the Interactions between Gold Nanoparticles and Antibody Proteins

作　　者：张赛[1] 彭运平[1,2] 何小维[1] 李文美[1,2] 刘晓云 

机构地区：[1]华南理工大学轻工与食品学院,广东广州510640 [2]万孚生物技术股份有限公司自检型快速诊断国家地方联合工程实验室,广东广州510663

出　　处：《分析科学学报》2014年第4期472-476,共5页Journal of Analytical Science

基　　金：国家科技支撑计划(No.2012BAK08B07);国家发改委创新平台建设项目(发改高技[2011]2041号)

摘　　要：本文运用透射电镜(TEM)、Zeta电位测量、紫外-可见吸收光谱(UV-Vis)、荧光光谱以及衰减全反射傅立叶变换红外光谱(ATR-FTIR)等技术手段,研究了免疫球蛋白G(IgG)与金纳米粒子的相互作用。结果表明,所制备的金纳米粒子呈均一分散的球形,抗体蛋白能够与金纳米粒子形成稳定的复合物。内源荧光光谱表明金纳米粒子对抗体蛋白的内源荧光有显著的静态猝灭,猝灭常数KSV=4.25×109 L·mol-1,同时金纳米粒子与抗体蛋白间有较强的作用,结合常数K=1.95×1014,结合位点数n为1.49。外源荧光光谱表明金纳米粒子与抗体蛋白之间的作用力主要是疏水相互作用。ATR-FTIR分析抗体蛋白与金纳米粒子作用前后蛋白二级结构的变化,结果显示,抗体蛋白有序结构含量降低,构象朝着更加松散的状态变化。The interactions between immunoglobulin G （IgG） and gold nanoparticles （AuNPs） were investigated by transmission electron microscopy （TEM）, Zeta potential measurements, UV-visible absorption spectroscopy （UV-Vis）, fluorescence spectroscopy, and Fourier transform infrared in combination with attenuated total reflection spectroscopy（ATR-FTIR）. The results showed that the prepared AuNPs were almost spherical, and were well dispersed without any form of aggregation. AuNPs-IgG bioconjugate system could form stable complexes. Intrinsic fluorescence spectra showed that AuNPs had a great static quenching effect on the intrinsic fluorescence of antibody proteins, and quenching constant Ksv was calculated to be 4.25 × 10^9L·mo1^-1. IgG bound to AuNPs with high affinity （binding constant K = 1. 95 × 10^14 , the number of binding sites n = 1. 49）. In addition, exogenous fluorescence spectra showed that the key interaction force was hydrophobic interaction. ATR-FTIR spectra of the protein in both native and AuNPs-IgG bioconjugate system were recorded to determine the secondary structure of IgG, which showed that the content of ordered structure decreased and conformational structures of IgG changed towards a more loose state.

关 键 词：金纳米粒子 抗体蛋白 荧光光谱 傅立叶变换红外光谱 二级结构 

分 类 号：O657.3[理学—分析化学]