title: Expression and characterization of cecropinXJ, a bioactive antimicrobial peptide fromBombyx mori(Bombycidae, Lepidoptera) inEscherichia coli.
abstract: Insect antimicrobial peptides (AMPs) have a broad antimicrobial spectrum. To aid the characterization of the gene function and further applications, we cloned the gene of cecropinXJ into the prokaryotic expression vector pET32a and expressed cecropinXJ inEscherichia coliBL2l (DE3). Following induction by isopropyl-β-D-thiogalactoside (IPTG), a 25 kDa fusion peptide of cecropinXJ with a tagged thioredoxin (Trx) protein was highly expressed inE. coli. The yield was 10 mg/l culture medium following purification on nickel-nitrilotriacetic acid (Ni-NTA) metal affinity chromatography matrices. The purified recombinant antibacterial peptide, cecropinXJ, retained a high stability againstStaphylococcus aureusover a temperature range from 4 to 100°C and a pH range from pH 2.0 to 12.0. The minimum inhibitory concentration (MIC) of the fusion protein againstS. aureuswas 0.4μM. The recombinant cecropinXJ is also cytotoxic to several types of human cancer cells.
authors.affiliation: Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, Xinjiang 830046, P.R. China ;
authors.forename: Lijie
authors.initials: L
authors.lastname: Xia
authors.forename: Fuchun
authors.initials: F
authors.lastname: Zhang
authors.forename: Zhongyuan
authors.initials: Z
authors.lastname: Liu
authors.forename: Ji
authors.initials: J
authors.lastname: Ma
authors.forename: Jianhua
authors.initials: J
authors.lastname: Yang
keywords: antibacterial activity; antimicrobial peptide; antitumor activity; prokaryotic expression