Shear Alignment of Bola-Amphiphilic Arginine-Coated Peptide Nanotubes

Author(s):Show less -

Hamley, Ian W. ; Burholt, Samuel ; Hutchinson, Jessica ; Castelletto, Valeria ; da Silva, Emerson Rodrigo ; Alves, Wendel ; Gutfreund, Philipp ; Porcar, Lionel ; Dattani, Rajeev ; Hermida-Merino, Daniel ; Newby, Gemma ; Reza, Mehedi ; Ruokolainen, Janne ; Stasiak, Joanna

• Document type: Journal article
• Source: Biomacromolecules; v. 18, n. 1, p. 141-149, JAN 2017.
• Web of Science Citations: 8

Abstract

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. (AU)

• FAPESP's process: 13/12674-6 - Structural investigations on model systems based on amphiphilic peptides
• Grantee: Emerson Rodrigo da Silva
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 15/24018-1 - Polymer-Peptide Conjugates for hydrogel formulation and its usage in detection
• Grantee: Wendel Andrade Alves
• Support Opportunities: Regular Research Grants