Identification and characterization of antimicrobial peptide, defensin, in the taiga tick, Ixodes persulcatus.

摘要: Ixodes persulcatus is the primary vector for human tick-borne diseases in Japan. A cDNA library was constructed from whole body homogenates of fed nymphs I. persulcatus. From this library, one encoding defensin-like antimicrobial peptide identified. The amino-acid sequence showed high similarity to those defensins other ticks and arthropods. defensin mRNA transcripts were detected at all life cycle stages found be predominantly expressed midguts adult female ticks, but not salivary glands, a finding corroborated by Western blotting analysis. To investigate function defensin, we examined its antibacterial activity evaluation growth several bacterial strains presence synthetic peptide. markedly inhibited Gram-positive bacteria including Staphylococcus aureus, Bacillus subtilis Corynebacterium renale, Gram-negative except Escherichia coli O157. In conclusion, these results suggest that may playing significant role defence against microbes bloodmeals.