These authors contributed equally to this work.
Delivery of Antibody Mimics into Mammalian Cells via Anthrax Toxin Protective Antigen
Version of Record online: 22 SEP 2014
© 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Volume 15, Issue 16, pages 2458–2466, November 3, 2014
How to Cite
Liao, X., Rabideau, A. E. and Pentelute, B. L. (2014), Delivery of Antibody Mimics into Mammalian Cells via Anthrax Toxin Protective Antigen. ChemBioChem, 15: 2458–2466. doi: 10.1002/cbic.201402290
- Issue online: 23 OCT 2014
- Version of Record online: 22 SEP 2014
- Manuscript Received: 5 JUN 2014
- Funded Access
- NSF. Grant Number: CHE-1351807
- Damon Runyon Cancer Research Foundation
- NERCE. Grant Number: U54 AI057159
- anthrax toxin;
- intracellular delivery;
- protein–protein interactions;
Antibody mimics have significant scientific and therapeutic utility for the disruption of protein–protein interactions inside cells; however, their delivery to the cell cytosol remains a major challenge. Here we show that protective antigen (PA), a component of anthrax toxin, efficiently transports commonly used antibody mimics to the cytosol of mammalian cells when conjugated to the N-terminal domain of LF (LFN). In contrast, a cell-penetrating peptide (CPP) was not able to deliver any of these antibody mimics into the cell cytosol. The refolding and binding of a transported tandem monobody to Bcr-Abl (its protein target) in chronic myeloid leukemia cells were confirmed by co-immunoprecipitation. We also observed inhibition of Bcr-Abl kinase activity and induction of apoptosis caused by the monobody. In a separate case, we show disruption of key interactions in the MAPK signaling pathway after PA-mediated delivery of an affibody binder that targets hRaf-1. We show for the first time that PA can deliver bioactive antibody mimics to disrupt intracellular protein–protein interactions. This technology adds a useful tool to expand the applications of these modern agents to the intracellular milieu.