【摘要】 目的为简化抗血小板P 选择素鼠/人嵌合单克隆抗体SZ 51/Hu的99mTc标记过程 ,并提高其99mTc标记效率 ,利用金属硫蛋白(MT)可与金属稳定结合的特点 ,通过基因工程的手段制备融合蛋白SZ 51/Hu MT。方法构建了SZ 51/Hu与MT的重组表达载体 ,并在小鼠骨髓瘤细胞Sp2/0中进行了目的融合蛋白的表达。结果该融合蛋白在Sp2/0细胞中的表达量为3mg/L。对融合蛋白的各项性质分析表明 ,该融合蛋白的相对分子质量(Mr)为180000 ,且具有双向结合的特异性 :即一方面保持了SZ 51与活化血小板P 选择素的特异结合能力 ;另一方面又具有MT高效结合金属的特性。99mTc标记研究表明 ,该分子不需预处理即可被99m Tc直接标记 ,标记率可达79 %。结论获得具有双向结合特异性的融合蛋白SZ 51/Hu MT ,为研制新型血栓导向显像剂开辟了新途径。更多还原

【Abstract】 Aim To improve 99mTc labeling efficiency and simplify label process of SZ 51/Hu, a mouse/human chimeric antibody against P selectin of human activated platelets,a fusion protein of SZ 51/Hu and metallothionein(MT), which is a native metal binding protein, was produced by genetic engineering. Methods The mouse MT I gene was inserted into the 3′end of CH3 of SZ 51/Hu. The expression vector constructed was transfected into a murine myeloma cell Sp2/0 with lipofectin. The positive cells were obtained by using drug and clonal selection. Then the expressed products were analyzed. Results The expression level of fusion protein was 3mg/L. Its relative molecule mass (Mr) was 180 000. It retained the specific P selection binding character of SZ 51, and obtained metal binding capability of MT. It could be labeled with 99mTc directly, and the labeling efficiency was up to 79%. Conclusion This fusion protein has both thrombus targeting and metal binding specificity. It will comtribute to targeted thrombus imaging.更多还原