γ显像在层析分离及蛋白分子位点密度测定中的应用  

Application of γ imaging in chromatographic separation and protein molecular site density determination

作　　者：张金赫[1,2] 李趣欢[3] 凌颖琛[3] 钟建秋[1] 尹吉林[2] 徐浩[1] 

机构地区：[1]暨南大学附属第一医院核医学科,广州510632 [2]广州军区广州总医院核医学科,广州510010 [3]华南理工大学生物科学与工程学院,广州510641

出　　处：《生物医学工程学杂志》2017年第3期445-448,共4页Journal of Biomedical Engineering

基　　金：广东省自然科学基金(2016A030313612)

摘　　要：本文用放射性核素标记以及单光子发射型计算机断层(SPECT)γ显像的方法,进行E-选择素蛋白分子位点密度测定,以探讨其实用价值。采用Indogen法对E-选择素蛋白分子抗体进行125I标记,标记产物经G25葡聚糖凝胶层析柱分离纯化,对分离出的样品排列在塑胶试管架上,用SPECT进行平面显像并定量分析。制备不同浓度的E-选择素标准溶液,将放射性计数换算为位点密度,作蛋白量位点密度标准曲线。标记产物经SPECT定量分析,E-选择素抗体标记率为78%;不同浓度样品饱和曲线显示,当浓度在0~1 mg/m L浓度范围时,得标准曲线为y=6 045.7x—51.166,决定系数R^2=0.997 9。研究结果表明,γ显像在放射性标记产物分析及位点密度测定时有一定实用价值。We in this study measured the site density of E-selectin in order to explore the practical pliability using radionuclide labeling method and y-imaging of single photon emission computer tomography （SPECT）. This method required labeling of antibody with ^125I using Indogen method and binding of the labeled antibody to E-selectin. Labeled E- selectin was separated and purified in a Sephadex G25 column. The different fractions of the eluants were imaged, analyzed and quantified with SPECT method. For measuring the saturation curve of E-selectin, 130 μL of E-selectin solution with different concentrations were added in a 48-well plate and incubated overnight at 4℃. After incubation, 130 μL of labeled antibody solution were added and kept incubated for 30 min. The resulted mixture was washed, and the radioactivity in each sample was detected by SPECT. The levels of radioactivity were translated to site densities, and were used to plot a standard curve. The labeled product was quantitatively analyzed with SPECT. The labeling rate of E-selectin was 78%. The saturation curve of different concentration samples showed that when the concentration was in the concentration range of 0-1 mg/mL, the standard curve was y=6 045.7x-51.166, R^2=0.997 9. Based on this finding, it could be concluded that γ-imaging is an important tool for analysis of radiolabeled product and determination of site density.

关 键 词：体层摄影术 发射型计算机 单光子 层析分离 E-选择素 位点密度 

分 类 号：R817[医药卫生—影像医学与核医学]