Xiang J, Koropatnick J, Qi Y, Luo X, Moyana T, Li K, Chen Y
Saskatoon Cancer Center, Department of Microbiology, University of Saskatchewan, Canada.
Immunology. 1993 Apr;78(4):574-81.
A hybrid anti-tumour B72.3 antibody/metallothionein protein B72.3MT-1 was produced by the construction of the expression vector mpSV2neo-EP1-B72.3MT-1. This vector contained the neo gene as a selection marker, the murine immunoglobulin promoter and enhancer, and the hybrid B72.3 heavy chain gene fragment with mouse metallothionein-1 cDNA gene ligated into its CH2 domain. The expression vector was transfected to the heavy chain loss mutant B72.3Mut(K) cell line. The hybrid protein B72.3MT-1 was purified from transfectant supernates using a Protein G column. We showed that the hybrid protein retained the binding reactivity for the TAG72 antigen as the original B72.3 antibody, and the metal-binding capacity of the native metallothionein molecule. Therefore, the bifunctional hybrid protein B72.3MT-1 may be very useful in cancer imaging when labelled with radionuclides such as 99mTc.
通过构建表达载体mpSV2neo-EP1-B72.3MT-1，制备了一种杂交抗肿瘤B72.3抗体/金属硫蛋白B72.3MT-1。该载体包含作为选择标记的neo基因、鼠免疫球蛋白启动子和增强子，以及杂交B72.3重链基因片段，其中小鼠金属硫蛋白-1 cDNA基因连接到其CH2结构域。将表达载体转染到重链缺失突变体B72.3Mut(K)细胞系中。使用蛋白G柱从转染上清液中纯化杂交蛋白B72.3MT-1。我们发现，该杂交蛋白保留了与TAG72抗原的结合反应性，如同原始的B72.3抗体一样，并且保留了天然金属硫蛋白分子的金属结合能力。因此，用99mTc等放射性核素标记时，双功能杂交蛋白B72.3MT-1在癌症成像中可能非常有用。
