Preparation And Biological Activity Of Anti-gastric Cancer Mgr1 Single-chain Antibody And Mgb2 Single-domain Antibody Detection

Monoclonal antibody MGr₁ could partially revert the multi-drug resistance of SGC7901/VCR cells in vitro. However, the efficacy of the antibody is likely to be improved by using engineered MGr₁ antibody when it is used in vivo. Single chain Fv antibody (ScFv) offers several advantages over its parent mouse monoclonal antibody, including lower immunogenicity , deeper tumor penetration, faster clearance from blood and relatively easy molecular manipulation. In this study, a ScFv derived from MGr₁ mAb was constructed and expressed.(1) The variable region genes of MGr₁ mAb, Gr₁V_H and Gr₁V_L, were amplified with RT-PCR kit by priming total RNA isolated from MGr₁ hybridoma cells with degenerate primers. The products were sequenced using automatic sequencer. Subgrouping was performed using Kabat Database through Internet. Gr₁V_H and Gr₁V_L belonged to II (A) and II subgroup respectively. Gr₁V_H encoded 116 amino acid residues and had a marked homology (96%) with the V_H gene of MMOLLVAR665. Gr₁V_L encoded 116 amino acid residues and had a marked homology (91%) with the V_L gene of ScFv MMOLLU131195.(2) MGr₁ ScFv DNA was assembled by overlapping extension of Gr₁V_H and linker-Gr₁V_L. The products were cloned into pRSET vector and expressed...