title: Expression, purification and biological activity assessment of romiplostim biosimilar peptibody.
abstract: BACKGROUND
  Romiplostim is a peptibody analogue of thrombopoietin (TPO) which regulates platelet production. This molecule consists of two main parts: Peptide sequences which like wild type TPO, mimics stimulation of TPO receptor and IgG1Fc, (Peptide + Antibody = Peptibody). This drug is used in treatment of chronic Immune Thrombocytopenic Purpura (ITP).
  
  
  METHODS
  In this project E. coli bacteria were transformed by a construct harboring peptibody fusion gene. This construct consisted of two repeated peptide sequences which have fused to Carboxyl group of IgG1Fc. Designed construct in E. coli host resulted in protein expression in cytoplasm as inclusion body. The inclusion bodies were separated, washed and after denaturation and solubilization, in the last stage the desired peptibodies were refolded and purified. The resulting peptibodies were characterized by SDS-PAGE and Western immunoblotting. The bioactivity were assessed in vivo using subcutaneous injection in mice.
  
  
  RESULTS
  Results showed accurate molecules were produced and purified. Also, in vivo experiment showed significant increment (more than two fold) of platelets compared to control group.
  
  
  CONCLUSIONS
  In this study laboratory scale production of recombinant romiplostim showed proper in-vivo bioactivity. This new approach in expression and purification of this recently introduced thrombopoietin receptor agonist drug may be followed by scale up of its production to response the chronic ITP patient's demand.
authors.affiliation: Biochemistry Department, Pasteur Institute of Iran, Tehran, 1316943551, Iran.
authors.forename: Shima
authors.initials: S
authors.lastname: Fayaz
authors.affiliation: Biochemistry Department, Pasteur Institute of Iran, Tehran, 1316943551, Iran. fard-esfahani@pasteur.ac.ir.
authors.forename: Pezhman
authors.initials: P
authors.lastname: Fard-Esfahani
authors.affiliation: Molecular Parasitology Laboratory, Department of Parasitology, Pasteur Institute of Iran, Tehran, 1316943551, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Golkar
authors.affiliation: Recombinant Protein Production Department, Research and Production Complex, Pasteur Institute of Iran, Karaj, 3159915111, Iran.
authors.forename: Mojgan
authors.initials: M
authors.lastname: Allahyari
authors.affiliation: Biochemistry Department, Pasteur Institute of Iran, Tehran, 1316943551, Iran.
authors.forename: Sedigheh
authors.initials: S
authors.lastname: Sadeghi
mesh_terms: D000818:Animals; D059451:Biosimilar Pharmaceuticals / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005260:Female; D008807:Mice, Inbred BALB C; D010957:Plasmids; D011961:Receptors, Fc / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D013926:Thrombopoietin / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology
chemical_list: D059451:Biosimilar Pharmaceuticals; D011961:Receptors, Fc; D011993:Recombinant Fusion Proteins; D013926:Thrombopoietin; C488777:romiplostim
keywords: Immune thrombocytopenic purpura (ITP); Peptibody; Romiplostim