title: A serine protease inhibitor from Musca domestica larva exhibits inhibitory activity against elastase and chymotrypsin.
abstract: OBJECTIVE
  Insect-derived serine protease inhibitors (serpins) exhibit multiple inhibitory activities, but so far, no functional roles for serpins of Musca domestica have been identified. Here, the functional features of M. domestica serine protease inhibitor (MDSPI16) were characterized.
  
  
  RESULTS
  Hundred forty seven differentially expressed genes including the MDSPI16 gene were screened by constructing the subtractive cDNA library. The 1154-bp full-length MDSPI16 gene was cloned, and the recombinant MDSPI16 serpin protein was expressed as a 42.6 kDa protein in an Escherichia coli expression system. The recombinant MDSPI16 protein was purified using Ni-NTA affinity chromatography, and the inhibitory activity of MDSPI16 was assessed. MDSPI16 did not inhibit trypsin, papain, or proteinase K but strongly inhibited elastase (Ki = 2.8 nM) and chymotrypsin (Ki = 28 nM). The inhibitory activity of MDSPI16 remained stable over from 37 to 100 °C and from pH 2 to 12.
  
  
  CONCLUSIONS
  The MDSPI16 exhibited inhibitory activity against elastase and chymotrypsin and the inhibitory activity remained stable.
authors.affiliation: College of Animal Science and Technology, Jilin Agricultural University, Xincheng Street No. 2888, Changchun, 130118, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Fiber Inspection Center of Jilin Province, Yiju Street No. 2699, Changchun, 130000, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Animal Science and Technology, Jilin Agricultural University, Xincheng Street No. 2888, Changchun, 130118, China.
authors.forename: Zhihuan
authors.initials: Z
authors.lastname: Pei
authors.affiliation: College of Animal Science and Technology, Jilin Agricultural University, Xincheng Street No. 2888, Changchun, 130118, China.
authors.forename: Wenting
authors.initials: W
authors.lastname: Li
authors.affiliation: College of Animal Science and Technology, Jilin Agricultural University, Xincheng Street No. 2888, Changchun, 130118, China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Zhang
authors.affiliation: College of Animal Science and Technology, Jilin Agricultural University, Xincheng Street No. 2888, Changchun, 130118, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.affiliation: College of Animal Science and Technology, Jilin Agricultural University, Xincheng Street No. 2888, Changchun, 130118, China.
authors.forename: Lingcong
authors.initials: L
authors.lastname: Kong
authors.affiliation: College of Animal Science and Technology, Jilin Agricultural University, Xincheng Street No. 2888, Changchun, 130118, China.
authors.forename: Shuming
authors.initials: S
authors.lastname: Liu
authors.affiliation: College of Animal Science and Technology, Jilin Agricultural University, Xincheng Street No. 2888, Changchun, 130118, China.
authors.forename: Xiuyun
authors.initials: X
authors.lastname: Jiang
authors.affiliation: College of Animal Science and Technology, Jilin Agricultural University, Xincheng Street No. 2888, Changchun, 130118, China. hongxia0731001@163.com.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Ma
mesh_terms: D000818:Animals; D002918:Chymotrypsin / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D015723:Gene Library; D006793:Houseflies / Q000378:metabolism*; D007814:Larva / Q000378:metabolism*; D010196:Pancreatic Elastase / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors
chemical_list: D015842:Serine Proteinase Inhibitors; D002918:Chymotrypsin; D010196:Pancreatic Elastase
keywords: Chymotrypsin inhibitor; Elastase inhibitor; Gene cloning; Musca domestica; Protein expression; Serine protease inhibitor; Serpins