Protein transduction assisted by polyethylenimine-cationized carrier proteins

Midori Kitazoe, Hitoshi Murata, Junichiro Futami, Takashi Maeda, Masakiyo Sakaguchi, Masahiro Miyazaki, Megumi Kosaka, Hiroko Tada, Masaharu Seno, Nam Ho Huh, Masayoshi Namba, Mitsuo Nishikawa, Yoshitake Maeda, Hidenori Yamada

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)


Previously, we have reported that cationized-proteins covalently modified with polyethylenimine (PEI) (direct PEI-cationization) efficiently enter cells and function in the cytosol [Futami et al. (2005) J. Biosci. Bioeng. 99, 95-103]. However, it may be more convenient if a protein could be delivered into cells just by mixing the protein with a PEI-cationized carrier protein having a specific affinity (indirect PEI-cationization). Thus, we prepared PEI-cationized avidin (PEI-avidin), streptavidin (PEI-streptavidin), and protein G (PEI-protein G), and examined whether they could deliver biotinylated proteins and antibodies into living cells. PEI-avidin (and/or PEI-streptavidin) carried biotinylated GFPs into various mammalian cells very efficiently. A GFP variant containing a nuclear localization signal was found to arrive even in the nucleus. The addition of a biotinylated RNase A derivative mixed with PEI-streptavidin to a culture medium of 3T3-SV-40 cells resulted in remarkable cell growth inhibition, suggesting that the biotinylated RNase A derivative entered cells and digested intracellular RNA molecules. Furthermore, the addition of a fluorescein-labeled anti-S100C (beta-actin binding protein) antibody mixed with PEI-protein G to human fibroblasts resulted in the appearance of a fluorescence image of actin-like filamentous structures in the cells. These results indicate that indirect PEI-cationization using non-covalent interaction is as effective as the direct PEI-cationization for the transduction of proteins into living cells and for expression of their functions in the cytosol. Thus, PEI-cationized proteins having a specific affinity for certain molecules such as PEI-streptavidin, PEI-avidin and PEI-protein G are concluded to be widely applicable protein transduction carrier molecules.

Original languageEnglish
Pages (from-to)693-701
Number of pages9
JournalJournal of biochemistry
Issue number6
Publication statusPublished - Jun 2005


  • Cationized carrier protein
  • Polyethylenimine
  • Protein G
  • Protein transduction
  • Streptavidin

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology


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