细胞凋亡检测剂^(125,131)I-Annexin Ⅴ的制备和初步评价  

Preparation and Preliminary Evaluation of^(125,131)I Labeled Human Recombinant Annexin Ⅴ

作　　者：陈大明[1] 金小海[1] 祁本忠[1] 罗志福[1] 贾兵[1] 张颖妹[2] 杨红伟[1] 张锦荣[1] 杜进[1] 马大龙[2] 王凡[1] 

机构地区：[1]中国原子能科学研究院同位素研究所,北京102413 [2]北京大学人类疾病基因研究中心

出　　处：《核化学与放射化学》2004年第4期209-214,共6页Journal of Nuclear and Radiochemistry

摘　　要：利用国内基因工程制备的AnnexinⅤ,采用Iodo Gen标记方法,研究了125,131I AnnexinⅤ的标记条件。在每管加入50μgIodo Gen、pH=6～7.8、AnnexinⅤ的质量浓度大于25μg/mL的条件下,反应10min,标记物的标记率大于80%。经PD 10色谱柱纯化后,标记物的放化纯度大于95%,室温下,标记物能稳定40h。在正常小鼠体内的生物分布实验表明,碘标记的AnnexinⅤ主要浓聚于肝、脾、肾,在体内清除很快。凋亡细胞结合分析表明,碘标记的AnnexinⅤ保持了较好的生物活性,对PS的解离常数K为8.53nmol/L,结合容量RT为1.23×106结合位点数/个细胞。所制备的细胞凋亡检测剂125,131I AnnexinⅤ可以用于进一步的动物模型或人体实验。The aim of this study is to evaluate the potential applicability of radioiodine-labeled human recombinant 36 kDa protein Annexin Ⅴ prepared in domestic conditions as an imaging agent for diagnosis of apoptosis. Experimental conditions for labeling of Annexin Ⅴ with^(125)I or^(131)I by Iodo-Gen method are optimized with respect to the concentrations of Iodo-Gen and the protein, reaction time, temperature, and pH value. Under the recommended conditions a labeling yield of higher than 80% may be achieved. The radiochemical purity of the labeled protein is increased to 95% or higher after purification with gel chromatography. The labeled compound^(125,131)I-Annexin Ⅴ prepared in this way is proved to be stable within 40 h at room temperature. The animal experiment with normal mice shows that^(125,131)I-Annexin Ⅴ is quickly distributed in whole body after injection and mainly accumulated in liver, kindneys and spleen. The clearance from blood is very fast. In vivo deiodination is also observed. Our in vitro experiments with Balb/C mouse thymus cells indicate that^(125,131)I-Annexin Ⅴ maintains high affinity to dexamethasone-induced apoptotic cells, K is 8.53 nmol/L, RT is 1.23×10~6 binding point/cell.

关 键 词：细胞凋亡 ANNEXIN V 制备 碘标记 稳定性 细胞结合分析 磷脂酰丝氨酸基团 核医学显像剂 

分 类 号：Q255[生物学—细胞生物学] R817[医药卫生—影像医学与核医学]