Expression of the antimicrobial peptide cecropin fused with human lysozyme in Escherichia coli.
Lysozyme is an abundant, cationic antimicrobial protein that plays an important role in host defense. It targets the beta (1-4) glycosidic bond between N-acetylglucosamine and N-acetylmuramic residues that make up peptidoglycan, making lysozyme highly active against Gram-positive bacteria. However, lysozyme alone is inactive against Gram-negative bacteria because it cannot reach the peptidoglycan layer. Cecropins are cationic molecules with a wide range of antimicrobial activities. The main target for these peptides is the cytoplasmic membrane. We resume that cecopin may disrupt the outer membrane, giving the enzyme access to the peptidoglycan in cell wall. So in the present study, novel hybrid protein combining Musca domestica cecropin (Mdc) with human lysozyme (Hly) was designed. The DNA sequence encoding recombination fusion protein Mdc-hly was cloned into the pET-32a vector for protein expression in Escherichia coli strain BL21 (DE3). The protein was expressed as a His-tagged fusion protein, and the Mdc-hly was released from the fusion by enterokinase cleavage and separated from the carrier thioredoxin. Antimicrobial activity assays showed that the recombinant fusion protein Mdc-hly has improved in vitro antimicrobial activity and action spectrum compared to Mdc and hly. Mdc-hly may have important potential application as a future safely administered human drug and food additive.
Lu
Xue-mei
XM
Guangdong University of Pharmaceutical, Guangzhou Higher Education Mega Center, People's Republic of China.
Jin
Xiao-bao
XB
Zhu
Jia-yong
JY
Mei
Han-fang
HF
Ma
Yan
Y
Chu
Fu-jiang
FJ
Wang
Yan
Y
Li
Xiao-bo
XB
D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D054807:Cecropins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D006793:Houseflies / Q000235:genetics; D006801:Humans; D009113:Muramidase / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D054807:Cecropins; D011993:Recombinant Fusion Proteins; D009113:Muramidase