title: Coupling of importin beta binding peptide on plasmid DNA: transfection efficiency is increased by modification of lipoplex's physico-chemical properties.
abstract: BACKGROUND
  Non-viral vectors for gene transfer are less immunogenic than viral vectors but also less efficient. Significant effort has focused on enhancing non-viral gene transfer efficiency by increasing nuclear import of plasmid DNA, particularly by coupling nuclear localization peptidic sequences to plasmid DNA.
  
  
  RESULTS
  We have coupled a 62-aminoacid peptide derived from hSRP1alpha importin beta binding domain, called the IBB peptide to plasmid DNA by using the heterobifunctional linker N-(4-azido-2,3,5,6 tetrafluorobenzyl)-6-maleimidyl hexanamide (TFPAM-6). When covalently coupled to plasmid DNA, IBB peptide did not increase the efficiency of cationic lipid mediated transfection. The IBB peptide was still able to interact with its nuclear import receptor, importin beta, but non-specifically. However, we observed a 20-fold increase in reporter gene expression with plasmid DNA / IBB peptide complexes under conditions of inefficient transfection. In which case, IBB was associated with plasmid DNA through self assembling ionic interaction.
  
  
  CONCLUSIONS
  The improvement of transfection activity was not due to an improved nuclear import of DNA, but rather by the modification of physicochemical properties of IBB peptide / plasmid complexes. IBB peptide increased lipoplex size and these larger complexes were more efficient for gene transfer.
authors.affiliation: UMR 7001 CNRS / ENSCP / Gencell S,A, Vitry sur Seine, France. carriere@drecam.cea.fr
authors.forename: Marie
authors.initials: M
authors.lastname: Carrière
authors.forename: Virginie
authors.initials: V
authors.lastname: Escriou
authors.forename: Aline
authors.initials: A
authors.lastname: Savarin
authors.forename: Daniel
authors.initials: D
authors.lastname: Scherman
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000235:genetics; D000595:Amino Acid Sequence; D001386:Azides / Q000737:chemistry; D002412:Cations; D045744:Cell Line, Tumor; D004247:DNA / Q000737:chemistry / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D008081:Liposomes / Q000737:chemistry*; D008301:Maleimides / Q000737:chemistry; D008969:Molecular Sequence Data; D019913:Nuclear Localization Signals / Q000235:genetics; D010316:Particle Size; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D010957:Plasmids / Q000737:chemistry / Q000235:genetics*; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000235:genetics; D014162:Transfection / Q000379:methods*; D028901:alpha Karyopherins / Q000737:chemistry / Q000378:metabolism; D028961:beta Karyopherins / Q000378:metabolism*
chemical_list: D001386:Azides; D002412:Cations; C423142:KPNA1 protein, human; D008081:Liposomes; D008301:Maleimides; D019913:Nuclear Localization Signals; D010455:Peptides; D011994:Recombinant Proteins; D028901:alpha Karyopherins; D028961:beta Karyopherins; C073709:N-(4-azido-2,3,5,6-tetrafluorobenzyl)-6-maleimidohexanamide; D004247:DNA