| Summary: | 碩士 === 國立中興大學 === 化學工程學系所 === 104 === Cecropin is a cationic antibacterial peptide and composed of 35-39 residues. This antibacterial peptide was identified to possess strong antibacterial activity and low toxicity against eukaryotic cell and some antibacterial peptides have the capability to kill cancer cell.
In this study, gene engineering was applied to produce the antibacterial peptide cecropinB2. In order to produce large amounts of cecropinB2, three host expression systems were chosen: Escherichia coli, Bacillus subtilis and Pichia pastoris. Three gene constructs were carried out as follows: cecropinB2 and intein-cecropinB2 and two kinds of affinity tags were selected: poly-His tag and chitin-binding domain. The results showed that the best production of cecropinB2 was the use of E. coli ER2566 harboring the gene of pTWIN-CBD-INT-cecropinB2. After 4hr major and 6hr induction culture, the yield of cecropinB2 protein was about 100 mg per liter culture broth. The fusion protein (CBD-INT-cecropinB2) was cleaved by the pH shift in the room temperature and purified cecropinB2 showed strong antibacterial activity under agar diffusion test. This study demonstrated that large amounts of recombinant peptide cecropinB2 with strong antibacterial activity can be produced via the gene engineering process.
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