title: A novel defensin-like peptide from salivary glands of the hard tick, Haemaphysalis longicornis.
abstract: A novel defensin-like antimicrobial peptide named longicornsin was isolated from the salivary glands of the hard tick, Haemaphysalis longicornis, using a 10-kDa cut-off Centriprep filter and reversed-phase high-performance liquid chromatography (RP-HPLC). Its amino acid sequence was determined as DFGCGQGMIFMCQRRCMRLYPGSTGFCRGFRCMCDTHIPLRPPFMVG by Edman degradation. The cDNA encoding longicornsin was cloned by cDNA library screening. The predicted protein from the cDNA sequence was composed of 78 amino acids including a mature longicornsin. It showed similarity with defensin-like peptides from other ticks by BLAST search. Different from most other tick defensin-like peptides, longicornsin had a C-terminal extension. Purified longicornsin exerted potent antimicrobial activities against bacteria and fungi. Interestingly, it even showed strong antimicrobial ability against drug-resistant microorganisms and Helicobacter pylori. The results of this study indicated that longicornsin is a potential candidate for novel antimicrobial drug design.
authors.affiliation: Key Laboratory of Microbiological Engineering of Agricultural Environment, Life Sciences College of Nanjing Agricultural University, Ministry of Agriculture, Nanjing, Jiangsu, 210095 China.
authors.forename: Xiangyun
authors.initials: X
authors.lastname: Lu
authors.forename: Qiaolin
authors.initials: Q
authors.lastname: Che
authors.forename: Yi
authors.initials: Y
authors.lastname: Lv
authors.forename: Meijuan
authors.initials: M
authors.lastname: Wang
authors.forename: Zekuan
authors.initials: Z
authors.lastname: Lu
authors.forename: Feifei
authors.initials: F
authors.lastname: Feng
authors.forename: Jingze
authors.initials: J
authors.lastname: Liu
authors.forename: Haining
authors.initials: H
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D023082:Defensins / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D005658:Fungi / Q000187:drug effects; D016480:Helicobacter pylori / Q000187:drug effects; D026863:Ixodidae / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D012469:Salivary Glands / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000890:Anti-Infective Agents; D023082:Defensins