Self-Assembly and Molecular Dynamics of Peptide-Functionalized Polyphenylene Dendrimers
The self-assembly mechanism and the associated molecular dynamics are studied for a series of poly-L-lysine-functionalized polyphenylene dendrimer melts as a function of the core size (generation), functionality, and polypeptide length using X-rays, solid-state NMR, calorimetry, and dielectric spectroscopy. A striking dependence of the polyphenylene self-assembly on the poly-L-lysine length is shown. In addition, the type ({alpha}helix/{beta}-sheet) of peptide secondary structure is controlled by the packing restrictions imposed by the polyphenylene core. We show that constrained poly-L-lysines can adopt different secondary structures from their linear analogues. The dynamic investigation revealed significant mobility associated solely with the polypeptide through three processes: a glass transition, a slower process associated with the relaxation of {alpha}-helical segments, and a glassy mode whose origin could be resolved by site-specific solid-state NMR techniques. Solid-state NMR studies further indicated a mobility gradient in going from the rigid peptide backbone to the side chains.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 930237
- Report Number(s):
- BNL-80919-2008-JA; TRN: US200822%%1414
- Journal Information:
- Macromolecules, Vol. 39
- Country of Publication:
- United States
- Language:
- English
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