Recombinant Production of TP4-LYC1, A New Chimeric Peptide with Targeted Cytotoxicity to HeLa Cells

Background: Tilapia Piscidin 4 (TP4) showed potential anti-tumor effects against various cancer cells. Lycosine-1 (LYC1), is another Antimicrobial Peptides (AMP) from spider venom with targeted penetration to cancer cells without any adverse effects on normal cells. The aim of this study was to produce a soluble recombinant fusion peptide in order to diminish the cytotoxicity of TP4 against normal cells. Methods: In order to express of TP4-LYC-1, TP4, and LYC1 in fusion to the inteins1/2 of pTWIN-1 vector, induction condition was optimized to earn soluble peptides. Auto-cleavage induction of inteins1/2 was performed based on IMPACT® manual and their effect on cell viability of HeLa and HUVEC cells was surveyed by MTT assay. Results: The best condition for accessing the most soluble peptide in fusion to the inteins was approximately similar for all three peptides (0.1 mM of IPTG, at 22°C). After the induction of self-cleavage of inteins, a band in 3, 3, and 6 kDa was observed on tricine-SDS-PAGE. The IC50 values of TP4-LYC1 and TP4 against HeLa cells were calculated as 0.83, and 2.75 µM, respectively. Conclusion: In the present study, a novel chimeric peptide, TP4-LYC1, was successfully produced. This fusion protein can act as a safe bio-molecule with potent cytotoxic effects against cancer cells, but the penetration ability and determination of cell death mechanism must be performed in order to have more precise view on the apoptosis induction of this recombinant peptide.