title: Identification of a small pacifastin protease inhibitor from Nasonia vitripennis venom that inhibits humoral immunity of host (Musca domestica).
abstract: Nasonia vitripennis is an important natural enemy of many flies. Pacifastin protease inhibitors (PPIs) play an important role in development and innate immunity of insects. In this study, cDNA sequences of a small pacifastin protease inhibitor in N. vitripennis (NvSPPI) was characterized and its open reading frame (ORF) contains 243bp. Real-time quantitative PCR (RT-qPCR) results revealed that NvSPPI mRNA were detected specifically in the venom apparatus, while they were expressed at low levels in other tissues tested. In the venom apparatus, NvSPPI transcript was highly expressed on the fourth day post eclosion and then declined gradually. The NvSPPI gene was recombinantly expressed utilizing a pGEX-4T-2 vector, and the recombinant products fused with glutathione S-transferase were purified. Inhibition of recombinant GST-NvSPPI to three serine protease inhibitors (trypsin, chymotrypsin, and protease K) were tested and results showed that recombinant NvSPPI could inhibit the activity of trypsin. Meanwhile, we evaluated the influence of the recombinant GST-NvSPPI on the phenoloxidase (PO) activity and prophenoloxidase (PPO) activation of hemolymph from a host pupa, Musca domestica. Results showed PPO activation in host hemolymph was inhibited by recombinant NvSPPI; however, there was no significant inhibition on the PO activity. Our results suggested that NvSPPI could inhibit PPO activation in host hemolymph and trypsin activity in vitro.
authors.affiliation: College of Life Sciences, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, PR China.
authors.forename: Cen
authors.initials: C
authors.lastname: Qian
authors.affiliation: College of Life Sciences, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, PR China.
authors.forename: Dan
authors.initials: D
authors.lastname: Liang
authors.affiliation: College of Life Sciences, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, PR China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Life Sciences, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, PR China.
authors.forename: Pei
authors.initials: P
authors.lastname: Wang
authors.affiliation: College of Life Sciences, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, PR China.
authors.forename: Saima
authors.initials: S
authors.lastname: Kausar
authors.affiliation: College of Life Sciences, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, PR China.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Wei
authors.affiliation: College of Life Sciences, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, PR China.
authors.forename: Baojian
authors.initials: B
authors.lastname: Zhu
authors.affiliation: College of Life Sciences, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: College of Life Sciences, Anhui Agricultural University, 130 Changjiang West Road, Hefei, 230036, PR China. Electronic address: anhuicansang@163.com.
authors.forename: Chaoliang
authors.initials: C
authors.lastname: Liu
mesh_terms: D000818:Animals; D004156:Catechol Oxidase / Q000378:metabolism; D004792:Enzyme Precursors / Q000378:metabolism; D005260:Female; D005982:Glutathione Transferase / Q000378:metabolism; D006458:Hemolymph / Q000378:metabolism; D006793:Houseflies / Q000187:drug effects*; D056724:Immunity, Humoral / Q000187:drug effects*; D008297:Male; D014442:Monophenol Monooxygenase / Q000378:metabolism; D016366:Open Reading Frames; D011506:Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D015842:Serine Proteinase Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D014862:Wasp Venoms / Q000737:chemistry*; D014863:Wasps
chemical_list: D004792:Enzyme Precursors; D011506:Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D015842:Serine Proteinase Inhibitors; D014862:Wasp Venoms; C106709:pacifastin; C038451:pro-phenoloxidase; D004156:Catechol Oxidase; D014442:Monophenol Monooxygenase; D005982:Glutathione Transferase
keywords: Biological control; Humoral immunity; Nasonia vitripennis; Prophenoloxidase activation; Serine protease inhibitors