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Nanotubes and bilayers in a model peptide system

Cenker, Celen LU ; Bucak, Seyda and Olsson, Ulf LU (2011) In Soft Matter 7(10). p.4868-4875
Abstract
The trifluoroacetate (tfa) salt of the peptide (ala)(6)lys self-assembles in water into very long, hollow nanotubes with a radius R = 26 nm, above a critical aggregation concentration (volume fraction), phi(cac) = 0.10. The peptides carry a net positive charge that ensures colloidal stability of the self-assembly structures through a long-range electrostatic repulsion. There is only a weak temperature dependence of phi(cac) from which an enthalpy of aggregation of -k(B)T per molecule is estimated. SAXS data show that the thickness of the nanotube wall, delta, is less than 1 nm indicating that the peptides form a monolayer in the nanotube wall. The nanotubes have a very large aspect ratio and form an ordered nematic or hexagonal phase.... (More)
The trifluoroacetate (tfa) salt of the peptide (ala)(6)lys self-assembles in water into very long, hollow nanotubes with a radius R = 26 nm, above a critical aggregation concentration (volume fraction), phi(cac) = 0.10. The peptides carry a net positive charge that ensures colloidal stability of the self-assembly structures through a long-range electrostatic repulsion. There is only a weak temperature dependence of phi(cac) from which an enthalpy of aggregation of -k(B)T per molecule is estimated. SAXS data show that the thickness of the nanotube wall, delta, is less than 1 nm indicating that the peptides form a monolayer in the nanotube wall. The nanotubes have a very large aspect ratio and form an ordered nematic or hexagonal phase. Because of the low delta/R ratio, the nanotube volume fraction grows very rapidly with increasing peptide concentration, phi, and reaches close packing already at phi = 0.15. When increasing the concentration further, there is a phase transition to a novel lamellar phase where the peptide molecules form bilayers consisting of two, presumably oppositely oriented, monolayers. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Soft Matter
volume
7
issue
10
pages
4868 - 4875
publisher
Royal Society of Chemistry
external identifiers
  • wos:000290227400040
  • scopus:79955652022
ISSN
1744-6848
DOI
10.1039/c0sm01186j
language
English
LU publication?
yes
id
3b2719f7-6a60-4f9c-86a5-ae4e5bd50ab2 (old id 1987081)
date added to LUP
2011-06-29 09:44:31
date last changed
2017-01-01 06:27:15
@article{3b2719f7-6a60-4f9c-86a5-ae4e5bd50ab2,
  abstract     = {The trifluoroacetate (tfa) salt of the peptide (ala)(6)lys self-assembles in water into very long, hollow nanotubes with a radius R = 26 nm, above a critical aggregation concentration (volume fraction), phi(cac) = 0.10. The peptides carry a net positive charge that ensures colloidal stability of the self-assembly structures through a long-range electrostatic repulsion. There is only a weak temperature dependence of phi(cac) from which an enthalpy of aggregation of -k(B)T per molecule is estimated. SAXS data show that the thickness of the nanotube wall, delta, is less than 1 nm indicating that the peptides form a monolayer in the nanotube wall. The nanotubes have a very large aspect ratio and form an ordered nematic or hexagonal phase. Because of the low delta/R ratio, the nanotube volume fraction grows very rapidly with increasing peptide concentration, phi, and reaches close packing already at phi = 0.15. When increasing the concentration further, there is a phase transition to a novel lamellar phase where the peptide molecules form bilayers consisting of two, presumably oppositely oriented, monolayers.},
  author       = {Cenker, Celen and Bucak, Seyda and Olsson, Ulf},
  issn         = {1744-6848},
  language     = {eng},
  number       = {10},
  pages        = {4868--4875},
  publisher    = {Royal Society of Chemistry},
  series       = {Soft Matter},
  title        = {Nanotubes and bilayers in a model peptide system},
  url          = {http://dx.doi.org/10.1039/c0sm01186j},
  volume       = {7},
  year         = {2011},
}