大肠菌素Colicin S4的重组表达、分离纯化和性质

Broad-spectrum of traditional antibiotics is one of the key factors that causing antibiotics-resistance of many bacteria. Bacteriocins are potential as the next generation of antibiotics due to their narrow-spectrum bactericidal activities. Many attentions have been paid on colicins because they were believed as safe as regard to human body. In this paper, the genes encoding colicin S4 and its immunity protein were cloned into pQE30 to produce colicin S4 expression vector pQE30-Col S4. Colicin S4 was highly expressed as soluble form in E coli M15 containing pQE30-Col S4. The yields ranged from 30 mg/L to 50 mg/L. The recombinant colicin S4 with an additional 6His-tag at its N-terminus is similar to the natural colicin S4 in antibacterial activity. It only showed bactericidal activity against E coli strains, which make it attractive to develop this protein as a novel antibiotic with narrow spectrum.