title: Mycoplasma synoviae enolase is a plasminogen/fibronectin binding protein.
abstract: BACKGROUND
  Mycoplasma synoviae is an avian pathogen that can lead to respiratory tract infections and arthritis in chickens and turkeys, resulting in serious economic losses to the poultry industry. Enolase reportedly plays important roles in several bacterial pathogens, but its role in M. synoviae has not been established. Therefore, in this study, the enolase encoding gene (eno) of M. synoviae was amplified from strain WVU1853 and expressed in E. coli BL21 cells. Then the enzymatic activity, immunogenicity and binding activity with chicken plasminogen (Plg) and human fibronectin (Fn) was evaluated.
  
  
  RESULTS
  We demonstrated that the recombinant M. synoviae enolase protein (rMsEno) can catalyze the conversion of 2-phosphoglycerate (2-PGA) to phosphoenolpyruvate (PEP), the Km and Vmax values of rMsEno were 1.1 × 10(-3) M and 0.739 μmol/L/min, respectively. Western blot and immuno-electron microscopy analyses confirmed that enolase was distributed on the surface and within the cytoplasm of M. synoviae cells. The binding assays demonstrated that rMsEno was able to bind to chicken Plg and human Fn proteins. A complement-dependent mycoplasmacidal assay demonstrated that rabbit anti-rMsEno serum had distinct mycoplasmacidal efficacy in the presence of complement, which also confirmed that enolase was distributed on the surface of M. synoviae. An inhibition assay showed that the adherence of M. synoviae to DF-1 cells pre-treated with Plg could be effectively inhibited by treatment with rabbit anti-rMsEno serum.
  
  
  CONCLUSIONS
  These results reveal that M. synoviae enolase has good catalytic activity for conversion of 2-PGA to PEP, and binding activity with chicken Plg and human Fn. Rabbit anti-rMsEno serum displayed an obvious complement-dependent mycoplasmacidal effect and adherent inhibition effect. These results suggested that the M. synoviae enolase plays an important role in M. synoviae metabolism, and could potentially impact M. synoviae infection and immunity.
authors.forename: Shijun
authors.initials: S
authors.lastname: Bao
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Guo
authors.forename: Shengqing
authors.initials: S
authors.lastname: Yu
authors.forename: Jiabo
authors.initials: J
authors.lastname: Ding
authors.forename: Lei
authors.initials: L
authors.lastname: Tan
authors.forename: Fanqin
authors.initials: F
authors.lastname: Zhang
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Sun
authors.forename: Xusheng
authors.initials: X
authors.lastname: Qiu
authors.forename: Guanghua
authors.initials: G
authors.lastname: Chen
authors.forename: Chan
authors.initials: C
authors.lastname: Ding
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002645:Chickens; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D005353:Fibronectins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics / Q000502:physiology; D006801:Humans; D045805:Mycoplasma synoviae / Q000201:enzymology*; D010751:Phosphopyruvate Hydratase / Q000235:genetics / Q000378:metabolism*; D010958:Plasminogen / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011994:Recombinant Proteins
chemical_list: D001426:Bacterial Proteins; D005353:Fibronectins; D011994:Recombinant Proteins; D010958:Plasminogen; D010751:Phosphopyruvate Hydratase