부산대학교 도서관

Sarcotoxin IA is a cecropin-type antibacterial protein produced by the flesh fly,Sarcophaga peregrina.Similar to other bactericidal small proteins produced by insects, sarcotoxin IA is released into the hemolymph of larvae and nymphs upon mechanical injury or bacterial infection. The gene (sarco) that encodes this toxin was introduced intoSaccharomyces cerevisiaeyeast cells and was expressed under a constitutive yeast promoter. The transformed yeast cells were grown in a liquid medium, and a peptide with a similar molecular size to that of the mature sarcotoxin IA was detected in the medium by Western blot analysis. The secreted sarcotoxin-like peptide (SLP) had a potent cytotoxic effect against several bacteria, including plant pathogenic bacteria, similar to the toxic effects of the authentic sarcotoxin IA.Erwinia carotovorawas more susceptible to the toxic medium thanPseudomonas solanacearumandPseudomonas syringaepv.lachrymans.Thus, yeast may be used in the production of such proteins for employment against various bacterial pathogens.