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Protein Transduction Domain Mimic (PTDM) Self-Assembly?
Nicholas D Posey1, Gregory N Tew2
1Department of Polymer Science and Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA. nposey@mail.pse.umass.edu.
Polymers
|April 10, 2019
Summary
Synthetic polymer mimics of protein transduction domains (PTDMs) do not self-assemble in solution. Protein binding is required to form PTDM-protein complexes, with PTDMs likely binding as single chains.
Area of Science:
- Biomedical research
- Nanotechnology
- Polymer chemistry
Background:
- Intracellular protein delivery is crucial for studying cellular functions and developing new therapies.
- Cell-penetrating peptides (CPPs) and protein transduction domains (PTDs) are common reagents for protein delivery.
- The role of self-assembly in the function of PTD mimics (PTDMs) was previously unknown.
Purpose of the Study:
- To investigate the self-assembly properties of synthetic polymer mimics of PTDs (PTDMs) in aqueous media.
- To determine if self-assembly influences the protein binding and delivery capabilities of PTDMs.
Main Methods:
- Interfacial tensiometry (IFT)
- Transmission electron microscopy (TEM)
- Transmittance assays (%T)
- Dynamic light scattering (DLS)
Main Results:
- PTDMs did not exhibit significant aggregation or self-assembly at relevant concentrations and timescales.
- Dynamic light scattering confirmed that protein presence is necessary to induce PTDM-protein complex formation.
- Evidence suggests that PTDMs bind to proteins as individual chains rather than through self-assembled structures.
Conclusions:
- Self-assembly is not a prerequisite for PTDM-mediated protein binding and delivery.
- PTDM-protein complex formation is initiated by the presence of the protein itself.
- These findings clarify the mechanism of action for PTDMs in intracellular protein delivery applications.
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