title: A novel antimicrobial peptide from salivary glands of the hard tick, Ixodes sinensis.
abstract: A novel antimicrobial peptide named as ixosin was isolated from the salivary glands of the hard tick, Ixodes sinensis, by gel filtration, ion exchange chromatography and reverse-phase high-performance liquid chromatography (RP-HPLC). Its amino acid sequence was determined as GLHKVMREVLGYERNSYKKFFLR by Edman degradation and its molecular weight was 2870.5 analyzed by fast atom bombardment (FAB) mass spectrometry. This is the first antimicrobial peptide from ticks that lacks cysteine in its primary structure. The cDNA encoding ixosin was cloned by cDNA library screening. The predicted protein from the cDNA sequence composed of 79 amino acids including mature ixosin. Purified ixosin exerted its antimicrobial activities against bacteria and fungi. No similarity was found by BLAST search to any database entries and, thus, our findings describe a novel antimicrobial peptide.
authors.affiliation: Kunming Institute of Zoology, Chinese Academy of Sciences, Toxicology Department, 32 East Jiao Chang Road, Kunming, Yunnan 650223, PR China.
authors.forename: Da
authors.initials: D
authors.lastname: Yu
authors.forename: Zonggen
authors.initials: Z
authors.lastname: Sheng
authors.forename: Xueqing
authors.initials: X
authors.lastname: Xu
authors.forename: Jianxu
authors.initials: J
authors.lastname: Li
authors.forename: Hailong
authors.initials: H
authors.lastname: Yang
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Liu
authors.forename: Huw H
authors.initials: HH
authors.lastname: Rees
authors.forename: Ren
authors.initials: R
authors.lastname: Lai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001483:Base Sequence; D002176:Candida albicans / Q000254:growth & development; D004926:Escherichia coli / Q000254:growth & development; D005260:Female; D006461:Hemolysis / Q000502:physiology; D018884:Ixodes / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D012471:Salivary Proteins and Peptides / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000254:growth & development
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D012471:Salivary Proteins and Peptides; C538726:ixosin protein, Ixodes sinensis