Shear alignment of bola-amphiphilic arginine-coated peptide nanotubes

Hamley, I. W. ORCID: https://orcid.org/0000-0002-4549-0926, Burholt, S., Hutchinson, J., Castelletto, V., da Silva, E. R., Alves, W., Gutfreund, P., Porcar, L., Dattani, R., Hermida-Merino, D., Newby, G., Reza, M., Ruokolainen, J. and Stasiak, J. (2017) Shear alignment of bola-amphiphilic arginine-coated peptide nanotubes. Biomacromolecules, 18 (1). pp. 141-149. ISSN 1525-7797 doi: 10.1021/acs.biomac.6b01425

Abstract/Summary

The bola-amphiphilic arginine-capped peptide RFL4RF self-assembles into nanotubes in aqueous solution. The nanostructure and rheology are probed by in situ simultaneous rheology/small-angle scattering experiments including rheo-SAXS, rheo-SANS, and rheo-GISANS (SAXS: small-angle X-ray scattering, SANS: small-angle neutron scattering, GISANS: grazing incidence small-angle neutron scattering). Nematic alignment of peptide nanotubes under shear is observed at sufficiently high shear rates under steady shear in either Couette or cone-and-plate geometry. The extent of alignment increases with shear rate. A shear plateau is observed in a flow curve measured in the Couette geometry, indicating the presence of shear banding above the shear rate at which significant orientation is observed (0.1–1 s–1). The orientation under shear is transient and is lost as soon as shear is stopped. GISANS shows that alignment at the surface of a cone-and-plate cell develops at sufficiently high shear rates, very similar to that observed in the bulk using the Couette geometry. A small isotope effect (comparing H2O/D2O solvents) is noted in the CD spectra indicating increased interpeptide hydrogen bonding in D2O, although this does not influence nanotube self-assembly. These results provide new insights into the controlled alignment of peptide nanotubes for future applications.

Additional Information	Correction at http://pubs.acs.org/doi/abs/10.1021/acs.biomac.7b00484
Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/68532
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry
Additional Information	Correction at http://pubs.acs.org/doi/abs/10.1021/acs.biomac.7b00484
Publisher	American Chemical Society
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