title: [Cloning, expression and immunoreactivity analysis of rhoptry protein 18 (rop18) from Toxoplasma gondii].
abstract: OBJECTIVE
  To clone and express rhoptry protein 18 (ROP18) gene of Toxoplasma gondii, and analyze its immunoreactivity.
  
  
  METHODS
  The genomic DNA was extracted from T. gondii (RH strain) tachyzoites. TgROP18 gene was amplified by PCR, and cloned into pET30a (+) vector. The constructed pET30a (+)-TgROP18 was transformed into E. coli BL21(DE3) and followed by expression of the protein induced by IPTG. The recombinant protein was analyzed through SDS-PAGE, and identified by Western blotting with mouse anti-T. gondii serum.
  
  
  RESULTS
  The TgROP18 gene was about 1 665 bp in length and encoded for a protein of 544 amino acid residues and the former 47 amino acids consisted signal peptide sequences. PCR, enzyme digestion and DNA sequencing confirmed that the recombinant plasmid pET30a (+)-TgROP18 was constructed. Bacteria containing recombinant plasmid pET30a (+)-TgROP18 expressed a soluble protein of His-TgROP18 (M, 59 800) after being induced with IPTG. His-TgROP18 reacted positively with mouse anti-T. gondii serum by Western blotting analysis.
  
  
  CONCLUSIONS
  The soluble His-TgROP18 protein shows certain immunoreactivity.
authors.affiliation: Institute of Pathogen Microbes and Immunology, Hebei North University, Zhangjiakou, 075000, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jin-Shun
authors.initials: JS
authors.lastname: Zhang
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Jia
authors.forename: Tian-Jun
authors.initials: TJ
authors.lastname: Jia
authors.forename: Zhi-Min
authors.initials: ZM
authors.lastname: Lu
authors.forename: Fang
authors.initials: F
authors.lastname: Zhou
mesh_terms: D003001:Cloning, Molecular; D015870:Gene Expression; D010957:Plasmids; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000276:immunology*; D015800:Protozoan Proteins / Q000235:genetics* / Q000276:immunology*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D014122:Toxoplasma / Q000235:genetics / Q000276:immunology
chemical_list: D015800:Protozoan Proteins; D011994:Recombinant Proteins; D017346:Protein Serine-Threonine Kinases; C556793:ROP18 protein, Toxoplasma gondii