Intracellular delivery of a peptide nucleic acid-based hybrid of an autophagy inducing peptide with a cell-penetrating peptide

Yoshiyuki Hakata, Suzuka Ishikawa, Takashi Ohtsuki, Masaaki Miyazawa, Mizuki Kitamatsu

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Development of an intracellular delivery method for functional peptides via cell-penetrating peptides (CPPs) expands peptide use in basic research and therapeutic applications. Although direct conjugation of a functional peptide with a CPP is the simplest method for delivery, this method has not always been reliable. CPPs usually contain several positively charged amino acids that potentially interact non-specifically with negatively charged molecules in cells and subsequently interfere with conjugated functional peptide function. Here we demonstrate a new intracellular delivery method for peptides in which a functional peptide is released from a positively charged CPP via peptide nucleic acids (PNAs). We prepared an 8-mer PNA conjugated to octa-arginine in tandem (PNA1-CPP) and linked its complementary PNA to an autophagy inducing peptide (PNA2-AIP) by solid-phase peptide synthesis. PNA1-CPP and PNA2-AIP formed a 1:1 hybrid via PNA1/PNA2 interaction, thereby indirectly but stably connecting the AIP to the CPP. PNA2-AIP was successfully delivered into cells in a hybrid formation-dependent manner and at least some portion of the PNA1-CPP/PNA2-AIP hybrids dissociated into PNA2-AIP and PNA1-CPP inside the cells. Notably, PNA2-AIP delivered to cells induced more autophagy than AIP directly conjugated to CPP (CPP-AIP). Further, the PNA hybrid did not induce significant cell death. These findings indicate that the PNA1/PNA2 hybrid can function as a molecular glue enabling the delivery of functional peptides into cells.

Original languageEnglish
Pages (from-to)1978-1986
Number of pages9
JournalOrganic and Biomolecular Chemistry
Issue number10
Publication statusPublished - Mar 14 2020

ASJC Scopus subject areas

  • Biochemistry
  • Physical and Theoretical Chemistry
  • Organic Chemistry


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