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An Intrinsically Disordered Peptide Facilitates Non-Endosomal Cell Entry.
Scott H Medina1, Stephen E Miller1, Allison I Keim1
1Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health Fort Detrick, 376 Boyle Street, Frederick, MD, 21702-1201, USA.
Angewandte Chemie (International Ed. in English)
|February 3, 2016
Summary
This study introduces CLIP6, a cell-penetrating peptide (CPP) that bypasses endosomal entrapment for direct cytoplasmic delivery. Its unique disordered structure ensures biocompatibility and serum stability, overcoming limitations of traditional CPPs.
Area of Science:
- Biochemistry
- Molecular Biology
- Biotechnology
Background:
- Cell-penetrating peptides (CPPs) facilitate intracellular delivery but often cause membrane lysis or endosomal entrapment.
- Structural folding in CPPs aids cellular entry but can limit their therapeutic applications.
- Existing CPPs face challenges with biocompatibility and serum stability.
Purpose of the Study:
- To introduce a novel intrinsically disordered peptide (CLIP6) for efficient and safe intracellular delivery.
- To elucidate the mechanism of cellular entry and biocompatibility of CLIP6.
- To demonstrate CLIP6's utility in delivering membrane-impermeable cargo to the cytoplasm.
Main Methods:
- Characterization of CLIP6's structure and biophysical properties.
- Investigation of CLIP6's cellular uptake mechanisms using advanced microscopy.
- Assessment of CLIP6's biocompatibility, serum stability, and cargo delivery efficiency.
- Site-directed mutagenesis to identify key residues influencing CLIP6 function.
Main Results:
- CLIP6 exclusively utilizes non-endosomal pathways for cellular membrane translocation.
- A single anionic glutamate residue is critical for CLIP6's disordered state, mechanism of entry, and biocompatibility.
- CLIP6 exhibits remarkable biocompatibility and stability in serum.
- CLIP6 successfully delivers membrane-impermeable cargo directly into the cell cytoplasm.
Conclusions:
- CLIP6 represents a new class of cell-penetrating peptides with a unique disordered structure.
- The identified glutamate residue is key to CLIP6's favorable properties, enabling safe and effective cytoplasmic delivery.
- CLIP6 offers a promising platform for delivering therapeutics that are limited by poor cell permeability and endosomal degradation.
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