title: Expression and purification of cyto-insectotoxin (Cit1a) using silkworm larvae targeting for an antimicrobial therapeutic agent.
abstract: Antimicrobial peptides (AMPs), both synthetic and from natural sources, have raised interest recently as potential alternatives to antibiotics. Cyto-insectotoxin (Cit1a) is a 69-amino-acid antimicrobial peptide isolated from the venom of the central Asian spider Lachesana tarabaevi. The synthetic gene Cit1a fused with the enhanced green fluorescent protein (EGFP) gene was expressed as the EGFP-Cit1a fusion protein using a cysteine protease-deleted Bombyx mori nucleopolyhedrovirus (BmNPV-CP(-)) bacmid in silkworm larva and pupa. The antimicrobial effect of the purified protein was assayed using disk diffusion and broth microdilution methods. The minimum inhibitory concentration of EGFP-Cit1a was also measured against several bacterial strains and showed similar antimicrobial activity to that of the synthetic Cit1a reported earlier. The EGFP-Cit1a fusion protein showed antibiotic activity toward gram-positive and gram-negative bacteria at the micromolar concentration level. These results show that active Cit1a can be produced and purified in silkworm, although this peptide is insecticidal. This study demonstrates the potential of active Cit1a purified from silkworms to use as an antimicrobial agent.
authors.affiliation: Laboratory of Biotechnology, Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan.
authors.forename: M P
authors.initials: MP
authors.lastname: Ali
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Yoshimatsu
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Suzuki
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kato
authors.forename: Enoch Y
authors.initials: EY
authors.lastname: Park
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D001097:Arachnida / Q000201:enzymology* / Q000235:genetics; D001419:Bacteria / Q000187:drug effects*; D016367:Baculoviridae / Q000235:genetics; D012831:Bombyx / Q000821:virology; D003001:Cloning, Molecular; D015870:Gene Expression; D005822:Genetic Vectors; D007814:Larva / Q000821:virology; D008826:Microbial Sensitivity Tests; D011679:Pupa / Q000821:virology; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D013111:Spider Venoms / Q000737:chemistry*
chemical_list: D023181:Antimicrobial Cationic Peptides; D011994:Recombinant Proteins; D013111:Spider Venoms