RESUMO
The tandem repeats of LFB15(W4,10)-HP(4-16) (LH) gene were cloned into vector pET32a(+) for recombinant expression in Escherichia coli. The E. coli C43(DE3) was successfully used as the expression host to avoid the cell death during induction in E. coli BL21(DE3). Fusion LH dimer was expressed as inclusion body at a portion of 35% of total cell protein and could be well purified by Ni(2+)-chelating chromatography. The recombinant LH was released by the cleavage of 50% formic acid, and its yield reached 11.3 mg/l with purity of 95%. The MIC(50) of 3.6 and 1.9 microM of recombinant LH against E. coli CMCC 44102 and Bacillus subtilis ATCC 6633 were determined, respectively. The results demonstrated that expression of tandem LH gene in E. coli C43(DE3) and formic acid cleavage would provide a potent efficient platform for the production of interested peptides.
Assuntos
Peptídeos Catiônicos Antimicrobianos/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Recombinantes de Fusão/genética , Peptídeos Catiônicos Antimicrobianos/biossíntese , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Bacillus subtilis/efeitos dos fármacos , Sequência de Bases , Cromatografia de Afinidade , Escherichia coli/efeitos dos fármacos , Formiatos/metabolismo , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/isolamento & purificaçãoRESUMO
The increasing problem of antibiotic resistance among pathogenic bacteria requires development of new antimicrobial agents. The pivotal assets of the antimicrobial peptide include potential for rapid bactericidal activity and low propensity for resistance. The four new antimicrobial hybrid peptides were designed based on peptides LFB15(W4,10), HP(2-20), and cecropin A according to the structure-activity relationship of the amphipathic and cationic antimicrobial peptides. Their structural parameters were accessed by bioinformatics tools, and then two hybrids with the most potential candidates were synthesized. The hybrid peptide LH28 caused an increase in antibiotic activity (MIC(50)=1.56-3.13 microM) against given bacterial strains and did not cause obvious hemolysis of rabbit erythrocytes at concentration of 3.13 microM with effective antimicrobial activity. The results demonstrate that evaluating the structural parameters could be useful for designing novel antimicrobial peptides.
