Spontaneous and x-ray-triggered crystallization at long range in self-assembling filament networks
Honggang Cui1, E Thomas Pashuck, Yuri S Velichko
1Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208, USA.
Science (New York, N.Y.)
|December 19, 2009
Summary
Like-charge peptide filaments spontaneously crystallize in networks due to repulsive forces. X-ray irradiation can trigger this crystallization, forming stable domains with potential biomedical applications.
Area of Science:
- Supramolecular chemistry
- Biophysics
- Materials science
Background:
- Supramolecular peptide filaments are key components in biological systems.
- Understanding self-assembly and ordering in these systems is crucial for biomaterials and nanotechnology.
Purpose of the Study:
- To investigate the spontaneous and triggered crystallization of like-charge supramolecular peptide filaments.
- To elucidate the mechanisms governing the stability of these crystalline structures.
Main Methods:
- Utilizing X-ray irradiation to induce crystallization in peptide filament networks.
- Analyzing interfilament separations and domain stability post-irradiation.
- Investigating the effect of ionic screening on ordering.
Main Results:
- Spontaneous long-range crystallization observed above a critical concentration.
- X-ray irradiation triggers crystallization at lower concentrations, forming stable domains up to 320 angstroms.
- Crystalline domains exhibit stability for hours after X-ray exposure.
- Ion screening suppresses the observed ordering.
Conclusions:
- Crystallization stability arises from a balance between repulsive forces (native or X-ray-induced charges) and mechanical entrapment.
- Similar phenomena may occur in cellular cytoskeletons.
- Potential applications in biomedicine and lithography through external induction.
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