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Effects of pH, ionic strength, calcium, and molecular mass on the arrangement of hydrophobic peptide helices at the air-water interface

Sjögren, Helen LU and Ulvenlund, Stefan LU (2004) In The Journal of Physical Chemistry Part B 108(52). p.20219-20227
Abstract
The influence of subphase characteristics (ionic strength, pH, and the presence of bridging cations) on the conformation and lateral orientation of the hydrophobic polypeptide poly-(L)-leucine (p-leu) has been investigated at the air-water interface with the surface film balance technique as well as with Brewster angle microscopy (BAM). In addition, Langmuir-Blodgett films of p-leu deposited on quartz and mica from different subphases have been studied by circular dichroism (CD) spectroscopy and atomic force microscopy (AFM). P-leu forms alpha-helices at the interface regardless of subphase characteristics. Long-range lateral orientation of the alpha-helical strands in the p-leu monolayer was obtained under conditions where attractive... (More)
The influence of subphase characteristics (ionic strength, pH, and the presence of bridging cations) on the conformation and lateral orientation of the hydrophobic polypeptide poly-(L)-leucine (p-leu) has been investigated at the air-water interface with the surface film balance technique as well as with Brewster angle microscopy (BAM). In addition, Langmuir-Blodgett films of p-leu deposited on quartz and mica from different subphases have been studied by circular dichroism (CD) spectroscopy and atomic force microscopy (AFM). P-leu forms alpha-helices at the interface regardless of subphase characteristics. Long-range lateral orientation of the alpha-helical strands in the p-leu monolayer was obtained under conditions where attractive interpeptide end-group interactions prevail. These interactions were obtained under conditions where (1) end-group charges lend a zwitterionic character to the peptide, thus enabling strong electrostatic attraction between adjacent strands, (2) there is a possibility for formation of carboxylic acid dimers, or (3) calcium bridges form between carboxylate end groups. These three cases correspond to an increase of the effective molecular mass of the peptide. It was concluded that such an increase, and thereby an increased long-range lateral orientation, can be obtained by enabling peptide end group attraction, but not by screening peptide end group repulsion. Kinetic studies of monolayer relaxation strongly suggest that the end-group effects influence the thermodynamic, as well as the kinetic, properties of peptide 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
The Journal of Physical Chemistry Part B
volume
108
issue
52
pages
20219 - 20227
publisher
The American Chemical Society
external identifiers
  • wos:000225925100048
  • scopus:11344265761
ISSN
1520-5207
DOI
10.1021/jp047858l
language
English
LU publication?
yes
id
02834c5e-f5cf-4dc2-b9af-4eb9cc202a39 (old id 153921)
date added to LUP
2007-07-12 11:37:26
date last changed
2017-07-30 04:45:09
@article{02834c5e-f5cf-4dc2-b9af-4eb9cc202a39,
  abstract     = {The influence of subphase characteristics (ionic strength, pH, and the presence of bridging cations) on the conformation and lateral orientation of the hydrophobic polypeptide poly-(L)-leucine (p-leu) has been investigated at the air-water interface with the surface film balance technique as well as with Brewster angle microscopy (BAM). In addition, Langmuir-Blodgett films of p-leu deposited on quartz and mica from different subphases have been studied by circular dichroism (CD) spectroscopy and atomic force microscopy (AFM). P-leu forms alpha-helices at the interface regardless of subphase characteristics. Long-range lateral orientation of the alpha-helical strands in the p-leu monolayer was obtained under conditions where attractive interpeptide end-group interactions prevail. These interactions were obtained under conditions where (1) end-group charges lend a zwitterionic character to the peptide, thus enabling strong electrostatic attraction between adjacent strands, (2) there is a possibility for formation of carboxylic acid dimers, or (3) calcium bridges form between carboxylate end groups. These three cases correspond to an increase of the effective molecular mass of the peptide. It was concluded that such an increase, and thereby an increased long-range lateral orientation, can be obtained by enabling peptide end group attraction, but not by screening peptide end group repulsion. Kinetic studies of monolayer relaxation strongly suggest that the end-group effects influence the thermodynamic, as well as the kinetic, properties of peptide monolayers.},
  author       = {Sjögren, Helen and Ulvenlund, Stefan},
  issn         = {1520-5207},
  language     = {eng},
  number       = {52},
  pages        = {20219--20227},
  publisher    = {The American Chemical Society},
  series       = {The Journal of Physical Chemistry Part B},
  title        = {Effects of pH, ionic strength, calcium, and molecular mass on the arrangement of hydrophobic peptide helices at the air-water interface},
  url          = {http://dx.doi.org/10.1021/jp047858l},
  volume       = {108},
  year         = {2004},
}