title: Stabilizing peptide fusion for solving the stability and solubility problems of therapeutic proteins.
abstract: OBJECTIVE
  Protein aggregation is a major stability problem of therapeutic proteins. We investigated whether a novel stabilizing peptide [acidic tail of synuclein (ATS) peptide] could be generally used to make a more stable and soluble form of therapeutic proteins, particularly those having solubility or aggregation problems.
  
  
  METHODS
  We produced ATS fusion proteins by fusing the stabilizing peptide to three representative therapeutic proteins, and then compared the stress-induced aggregation profiles, thermostability, and solubility of them. We also compared the in vivo stability of these ATS fusion proteins by studying their pharmacokinetics in rats.
  
  
  RESULTS
  The human growth hormone-ATS (hGH-ATS) and granulocyte colony-stimulating factor-ATS (G-CSF-ATS) fusion proteins were fully functional as determined by cell proliferation assay, and the ATS fusion proteins seemed to be very resistant to agitation, freeze/thaw, and heat stresses. The introduction of the ATS peptide significantly increased the storage and thermal stabilities of hGH and G-CSF. The human leptin-ATS fusion protein also seemed to be very resistant to aggregation induced by agitation, freeze/thaw, and heat stresses. Furthermore, the ATS peptide greatly increased the solubility of the fusion proteins. Finally, pharmacokinetic studies in rats revealed that the ATS fusion proteins are also more stable in vivo.
  
  
  CONCLUSIONS
  Our data demonstrate that a more stable and soluble form of therapeutic proteins can be produced by fusing the ATS peptide.
authors.affiliation: ATGen Inc., Sung Nam, Kyung Ki Do, South Korea.
authors.forename: Eui Nam
authors.initials: EN
authors.lastname: Lee
authors.forename: Young Mok
authors.initials: YM
authors.lastname: Kim
authors.forename: Hye Ja
authors.initials: HJ
authors.lastname: Lee
authors.forename: Sang Woo
authors.initials: SW
authors.lastname: Park
authors.forename: Han Young
authors.initials: HY
authors.lastname: Jung
authors.forename: Jae Myun
authors.initials: JM
authors.lastname: Lee
authors.forename: Yong-Ho
authors.initials: YH
authors.lastname: Ahn
authors.forename: Jongsun
authors.initials: J
authors.lastname: Kim
mesh_terms: D000818:Animals; D004355:Drug Stability; D004356:Drug Storage; D016179:Granulocyte Colony-Stimulating Factor / Q000737:chemistry / Q000235:genetics / Q000493:pharmacokinetics; D006358:Hot Temperature; D019382:Human Growth Hormone / Q000737:chemistry / Q000235:genetics / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D010455:Peptides / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry* / Q000235:genetics / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000235:genetics / Q000493:pharmacokinetics; D012995:Solubility; D051844:alpha-Synuclein / Q000737:chemistry* / Q000235:genetics
chemical_list: D010455:Peptides; D011506:Proteins; D011993:Recombinant Fusion Proteins; D051844:alpha-Synuclein; D019382:Human Growth Hormone; D016179:Granulocyte Colony-Stimulating Factor