›› 2013, Vol. 25 ›› Issue (6): 0-1214.

• 动物科学 •    

Fusion expression of Silkie Cathelicidins genes in Escherichia coli and detection of their antibacterial activity

WU Jing;LIANG Yong\|li;SHI Yyu\|ying;LI Yyu\|feng;MA Xiu\|li;JIANG Yi\|fei;SONG Min\|xun;*   

  1. 1 Poultry Institute of Shandong Academy of Agricultural Sciences, Jinan 250023, China;2 School of Life Sciences, Shandong University, Jinan 250100, China;3 Shandong Experimental Animal Center, Jinan 250002, China
  • Received:1900-01-01 Revised:1900-01-01 Online:2013-11-25 Published:2013-11-25

Abstract: Cathelicidins comprise a family of antimicrobial peptides sharing a highly conserved cathelin domain, they play a critical role in the innate immune system of chicken. In order to investigate the antibacterial activity of recombinant Cathelicidins, the putative mature peptide coding fragments of CathL\|1, CathL\|2, CathL\|3 genes were amplified from the plasmid pMD\|CathL containing Cathelicidins cDNA sequences, and then subcloned into pET\|30a(+) plasmid respectively. The recombinant vectors named pET30\|CathL1S, pET30\|CathL2S and pET30\|CathL3S were transformed into the competent cell of E.coli Rosetta(DE3). The positive clones were cultured and induced to express target protein by addition of 10 mmol·L-1 IPTG in LB. SDS\|PAGE and Western blot analysis demonstrated that cathelicidins genes were expressed in the form of fusion protein, and the apparent molecular weight of expression products were 70 kD, 80 kD, 75 kD, respectively. The recombinant Cathelicidins were able to kill both Gram negative bacteria and Gram positive bacteria by the means of agar well diffusion assay (AWDA), especially for the antibiotic\|resistant strains.

Key words: Silkie, Cathelicidins antimicrobial peptide, fusion expression, purification, antibacterial activity