title: Identification and functional characterization of alpha-enolase from Taenia pisiformis metacestode.
abstract: Enolase belongs to glycolytic enzymes with moonlighting functions. The role of enolase in Taenia species is still poorly understood. In this study, the full length of cDNA encoding for Taenia pisiformis alpha-enolase (Tpeno) was cloned from larval parasites and soluble recombinant Tpeno protein (rTpeno) was produced. Western blot indicated that both rTpeno and the native protein in excretion-secretion antigens from the larvae were recognized by anti-rTpeno monoclonal antibodies (MAbs). The primary structure of Tpeno showed the presence of a highly conserved catalytic site for substrate binding and an enolase signature motif. rTpeno enzymatic activities of catalyzing the reversible dehydration of 2-phosphoglycerate (2-PGA) to phosphoenolpyruvate (PEP) and vice versa were shown to be 30.71 ± 2.15 U/mg (2-PGA to PEP) and 11.29 ± 2.38 U/mg (PEP to 2-PGA), respectively. Far-Western blotting showed that rTpeno could bind to plasminogen, however its binding ability was inhibited by ϵ-aminocaproic acid (ϵACA) in a competitive ELISA test. Plasminogen activation assay showed that plasminogen bound to rTpeno could be converted into active plasmin using host-derived activators. Immunohistochemistry and immunofluorescence indicated that Tpeno was distributed in the bladder wall of the metacestode and the periphery of calcareous corpuscles. In addition, a vaccine trial showed that the enzyme could produce a 36.4% protection rate in vaccinated rabbits against experimental challenges from T. pisiformis eggs. These results suggest that Tpeno with multiple functions may play significant roles in the migration, growth, development and adaptation of T. pisiformis for survival in the host environment.
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China.
authors.forename: Aijiang
authors.initials: A
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China.
authors.forename: Xueliang
authors.initials: X
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: You
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China.
authors.forename: Junling
authors.initials: J
authors.lastname: Hou
authors.affiliation: Henan Institute of Science and Technology, Xinxiang 453003, China.
authors.forename: Qiuxia
authors.initials: Q
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China. Electronic address: luoxuenong@caas.cn.
authors.forename: Xuenong
authors.initials: X
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China. Electronic address: caixuepeng@caas.cn.
authors.forename: Xuepeng
authors.initials: X
authors.lastname: Cai
mesh_terms: D000818:Animals; D015153:Blotting, Western; D018076:DNA, Complementary / Q000235:genetics*; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D010751:Phosphopyruvate Hydratase / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D010958:Plasminogen / Q000378:metabolism*; D011817:Rabbits; D013621:Taenia / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D014611:Vaccination
chemical_list: D018076:DNA, Complementary; D010958:Plasminogen; D010751:Phosphopyruvate Hydratase
keywords: Calcareous corpuscles; Enolase; Plasminogen binding; Taenia pisiformis metacestode