Efficient Delivery of Structurally Diverse Protein Cargo into Mammalian Cells by a Bacterial Toxin

Anick Auger, Minyoung Park, Felix Nitschke, Lori M. Minassian, Greg L. Beilhartz, Berge A. Minassian, Roman A. Melnyk

Research output: Contribution to journalArticlepeer-review

34 Scopus citations


Platforms enabling targeted delivery of proteins into cells are needed to fully realize the potential of protein-based therapeutics with intracellular sites-of-action. Bacterial toxins are attractive systems to consider as templates for designing protein transduction systems as they naturally bind and enter specific cells with high efficiency. Here we investigated the capacity of diphtheria toxin to function as an intracellular protein delivery vector. We report that diphtheria toxin delivers an impressive array of passenger proteins spanning a range of sizes, structures, and stabilities into cells in a manner that indicates that they are "invisible" to the translocation machinery. Further, we show that α-amylase delivered into cells by a detoxified diphtheria toxin chimera digests intracellular glycogen in live cells, providing evidence that delivered cargo is folded, active, and abundant. The efficiency and versatility of diphtheria toxin over existing systems open numerous possibilities for intracellular delivery of bioactive proteins.

Original languageEnglish (US)
Pages (from-to)2962-2971
Number of pages10
JournalMolecular Pharmaceutics
Issue number8
StatePublished - Aug 3 2015


  • diphtheria toxin
  • intracellular protein delivery
  • toxin translocation

ASJC Scopus subject areas

  • Molecular Medicine
  • Pharmaceutical Science
  • Drug Discovery


Dive into the research topics of 'Efficient Delivery of Structurally Diverse Protein Cargo into Mammalian Cells by a Bacterial Toxin'. Together they form a unique fingerprint.

Cite this