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Forces between Hydrophilic Surfaces Adsorbed with Apolipoprotein AII Alpha Helices.

Ramos, S; Campos-Terán, J; Mas-Oliva, J; Nylander, Tommy LU and Castillo, R (2008) In Langmuir 24(16). p.8568-8575
Abstract
To provide better understanding of how a protein secondary structure affects protein-protein and protein-surface interactions, forces between amphiphilic alpha-helical proteins (human apolipoprotein AII) adsorbed on a hydrophilic surface (mica) were measured using an interferometric surface force apparatus (SFA). Forces between surfaces with adsorbed layers of this protein are mainly composed of electrostatic double layer forces at large surface distances and of steric repulsive forces at small distances. We suggest that the amphiphilicity of the alpha-helix structure facilitates the formation of protein multilayers next to the mica surfaces. We found that protein-surface interaction is stronger than protein-protein interaction, probably... (More)
To provide better understanding of how a protein secondary structure affects protein-protein and protein-surface interactions, forces between amphiphilic alpha-helical proteins (human apolipoprotein AII) adsorbed on a hydrophilic surface (mica) were measured using an interferometric surface force apparatus (SFA). Forces between surfaces with adsorbed layers of this protein are mainly composed of electrostatic double layer forces at large surface distances and of steric repulsive forces at small distances. We suggest that the amphiphilicity of the alpha-helix structure facilitates the formation of protein multilayers next to the mica surfaces. We found that protein-surface interaction is stronger than protein-protein interaction, probably due to the high negative charge density of the mica surface and the high positive charge of the protein at our experimental conditions. Ellipsometry was used to follow the adsorption kinetics of this protein on hydrophilic silica, and we observed that the adsorption rate is not only controlled by diffusion, but rather by the protein-surface interaction. Our results for dimeric apolipoprotein AII are similar to those we have reported for the monomeric apolipoprotein CI, which has a similar secondary structure but a different peptide sequence and net charge. Therefore, the observed force curves seem to be a consequence of the particular features of the amphiphilic alpha-helices. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Langmuir
volume
24
issue
16
pages
8568 - 8575
publisher
The American Chemical Society
external identifiers
  • wos:000258377900030
  • pmid:18652418
  • scopus:50849131197
ISSN
0743-7463
DOI
10.1021/la800348y
language
English
LU publication?
yes
id
e788ad35-327f-4861-acda-b3c73214a304 (old id 1180875)
date added to LUP
2008-10-16 16:07:47
date last changed
2017-01-01 05:17:57
@article{e788ad35-327f-4861-acda-b3c73214a304,
  abstract     = {To provide better understanding of how a protein secondary structure affects protein-protein and protein-surface interactions, forces between amphiphilic alpha-helical proteins (human apolipoprotein AII) adsorbed on a hydrophilic surface (mica) were measured using an interferometric surface force apparatus (SFA). Forces between surfaces with adsorbed layers of this protein are mainly composed of electrostatic double layer forces at large surface distances and of steric repulsive forces at small distances. We suggest that the amphiphilicity of the alpha-helix structure facilitates the formation of protein multilayers next to the mica surfaces. We found that protein-surface interaction is stronger than protein-protein interaction, probably due to the high negative charge density of the mica surface and the high positive charge of the protein at our experimental conditions. Ellipsometry was used to follow the adsorption kinetics of this protein on hydrophilic silica, and we observed that the adsorption rate is not only controlled by diffusion, but rather by the protein-surface interaction. Our results for dimeric apolipoprotein AII are similar to those we have reported for the monomeric apolipoprotein CI, which has a similar secondary structure but a different peptide sequence and net charge. Therefore, the observed force curves seem to be a consequence of the particular features of the amphiphilic alpha-helices.},
  author       = {Ramos, S and Campos-Terán, J and Mas-Oliva, J and Nylander, Tommy and Castillo, R},
  issn         = {0743-7463},
  language     = {eng},
  number       = {16},
  pages        = {8568--8575},
  publisher    = {The American Chemical Society},
  series       = {Langmuir},
  title        = {Forces between Hydrophilic Surfaces Adsorbed with Apolipoprotein AII Alpha Helices.},
  url          = {http://dx.doi.org/10.1021/la800348y},
  volume       = {24},
  year         = {2008},
}