title: A Kunitz-type proteinase inhibitor from the midgut of the ixodid tick, Haemaphysalis longicornis, and its endogenous target serine proteinase.
abstract: Although previous studies strongly suggested the involvement of serine proteases in blood digestion in the midgut of ticks, the regulating molecules of these proteinases are still unidentified. A novel Haemaphysalis longicornis Kunitz-type serine proteinase inhibitor with a single Kunitz-domain (HlMKI) has been identified and its co-localization with a midgut-derived serine proteinase (HlSP) within the epithelial cells has been demonstrated. Recombinant HlMKI inhibited the hydrolytic activity of HlSP, suggesting that HlMKI is a possible inhibitor of HlSP and may be part of a regulatory system of midgut serine proteinases.
authors.affiliation: Laboratory of Parasitic Diseases, National Institute of Animal Health, 3-1-5 Kanondai, Tsukuba, Ibaraki, Japan.
authors.forename: Takeharu
authors.initials: T
authors.lastname: Miyoshi
authors.forename: Naotoshi
authors.initials: N
authors.lastname: Tsuji
authors.forename: M Khyrul
authors.initials: MK
authors.lastname: Islam
authors.forename: M Abdul
authors.initials: MA
authors.lastname: Alim
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hatta
authors.forename: Kayoko
authors.initials: K
authors.lastname: Yamaji
authors.lastname: Anisuzzaman
authors.forename: Kozo
authors.initials: K
authors.lastname: Fujisaki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003593:Cytoplasm / Q000201:enzymology; D004847:Epithelial Cells / Q000201:enzymology; D041981:Gastrointestinal Tract / Q000201:enzymology*; D026863:Ixodidae / Q000201:enzymology*; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D057057:Serine Proteases / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000378:metabolism*
chemical_list: D015842:Serine Proteinase Inhibitors; D057057:Serine Proteases