The Construction Of Engineered And Energized Fusion Proteins Consisting Of Epidermal Growth Factor Receptor Specific Ligand Oligopeptide And Lidamycin And Its Antitumor Activity

It is known that the huge molecular size of mAb conjugated with toxin has become one of the major obstructions when applied in therapy of solid tumors at the present time. Ligand oligopeptide GE7 that can specifical bind to epidermal growth factor receptor (EGFR) has the characteristics of specifically binding to EGFR over-expressing tumor cells. This is an attractive approach to the study of growth factor receptor targeting drugs. In this study, we constructed both energized fusion protein SG-LDP-AE that consists of ligand oligopeptide to EGFR and lidamycin, and complete recombinant apoprotein of lidamycin (rLDP), respectively. Furthermore, the biological activity of the proteins was investigated. In order to obtain smaller size of active lidamycin. we tried to construct truncated lidamycin apoprotein (LDP) through DNA recombination.1. The construction of engineered and energized fusion protein consisting of ligand oligopeptide to EGFR and lidamycin and its antitumor activityIt is an important characteristic of epithelial origin human tumors that over-expressing epidermal growth factor receptor and it has close relationship with poor prognosis of patients. EGFR can be regarded as a perfect target in tumor-targeting therapy. Lidamycin (LDM, also called C-1027). a macromolecular peptide antitumor antibiotic, is a potential "effector" agent for tumor -targeting drugs owing to its extremely potent cytotoxicity against cancer cells and its marked antitumor efficacy in vivo. Lidamycin consists of an apoprotein (LDP) and an active enediyne chromophore (AE), which can be separated and reconstituted. Therefore, it is possible to genetically fuse LDP with the ligand oligopeptide specifical binding to EGFR, then rejoin the chromophore AE to form energized targeted drugs.Gene fragment of EGFR ligand oligopeptide fused with LDP was obtained by PCR, then it was inserted into plasmid pET-30a(+) to construct recombinant expressing plasmid pET30GLDP. After that, gene sequence of signal peptide pelB...