[Antibacterial activity of recombinant thanatin expressed by E.coli ER2566].
OBJECTIVE
To express antibacterial peptide thanatin in the prokaryotic expression system and test its antibacterial activity.


METHODS
The DNA sequence coding for the 21 peptides of thanatin was synthesized using the preferred genetic codes of E. coli, cloned into pTYB11 plasmid, and transformed into E.coli ER2566. The expression of thanatin fused with intein was induced by IPTG in E.coli, and intein-thanatin specifically bound to the column through intein tag was cleaved overnight at 4 degrees celsius; in DTT/cysteine buffer.


RESULTS
The cleaved thanatin was eluted with a protein concentration of 245 microg/ml in the first 4 ml. The purified thanatin had showed strong antibacterial activities against G- bacteria such as Shigella flexneri, Klebsiella pneumoniae, Shigella snnei, Escherichia coli O157, toxin producing Escherichia coli, Pseudomonas aeruginosa, and fungi such as Candida albicans, with especial potency in killing drug-resistant Klebsiella pneumoniae, Pseudomonas aeruginosa, and extended-spectrum beta-lactamases (ESBL)-producing E.coli. Eighty strains of drug-resistant (ESBL-producing) and 30 strains of sensitive E. coli were used for anti-bacterial assay, and no significant differences in the antibacterial activity of thanatin were found between the sensitive and drug-resistant E. coli (P>0.05).


CONCLUSIONS
The recombinant thanatin obtained shows strong antibacterial activity against drug-resistant and sensitive bacteria, and can be a potential substitute for routine antibiotics in the treatment of G- bacterial infections.
Wang
Pei-zhen
PZ
Department of Etio-Biology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China. wpz20080808@126.com
Gu
Jin-bao
JB
Luo
Jun
J
Peng
Hong-juan
HJ
D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005822:Genetic Vectors / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D011994:Recombinant Proteins; C098076:thanatin