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Structure of SP-B/DPPC Mixed Films Studied by Neutron Reflectometry.

Fullagar, Wilfred LU ; Holt, Stephen A and Gentle, Ian R (2008) In Biophysical Journal First Published August 15, 2008.
Abstract
The structures of films of SP-B and mixtures of SP-B and DPPC at the air/water interface have been studied by neutron reflectometry (NR) and Langmuir film balance methods. From the film balance studies we observe that at very high pressures the isotherms of pure DPPC and SP-B/DPPC mixtures very nearly overlay one another, suggesting that the SP-B is being excluded from the film. The use of multiple contrasts with NR at a range of surface pressures has enabled the mixing and 'squeeze out' of the DPPC and SP-B mixtures to be studied. We are able to identify the SP-B component of the interfacial structure and its position as a function of surface pressure. The mixtures are initially a homogeneous layer at low surface pressures. At higher... (More)
The structures of films of SP-B and mixtures of SP-B and DPPC at the air/water interface have been studied by neutron reflectometry (NR) and Langmuir film balance methods. From the film balance studies we observe that at very high pressures the isotherms of pure DPPC and SP-B/DPPC mixtures very nearly overlay one another, suggesting that the SP-B is being excluded from the film. The use of multiple contrasts with NR at a range of surface pressures has enabled the mixing and 'squeeze out' of the DPPC and SP-B mixtures to be studied. We are able to identify the SP-B component of the interfacial structure and its position as a function of surface pressure. The mixtures are initially a homogeneous layer at low surface pressures. At higher surface pressures the SP-B is squeezed out of the lipid layer into the subphase, with the first signs detected at 30 mN m(-1). At 50 mN m(-1) the subphase is almost completely excluded from the DPPC layer with the SP-B content significantly reduced. Only a small amount of DPPC appears to be associated with the squeezed out SP-B. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
surfactant protein, squeeze-out, SP-B, pulmonary surfactant, lung surfactant
in
Biophysical Journal
volume
First Published August 15, 2008
publisher
Cell Press
external identifiers
  • pmid:18708453
  • scopus:58149311144
ISSN
1542-0086
DOI
10.1529/biophysj.108.134395
language
English
LU publication?
yes
id
3e2b8002-76d0-4ecb-87a5-ddfe390323df (old id 1223131)
date added to LUP
2008-10-20 12:37:49
date last changed
2017-01-01 04:23:00
@article{3e2b8002-76d0-4ecb-87a5-ddfe390323df,
  abstract     = {The structures of films of SP-B and mixtures of SP-B and DPPC at the air/water interface have been studied by neutron reflectometry (NR) and Langmuir film balance methods. From the film balance studies we observe that at very high pressures the isotherms of pure DPPC and SP-B/DPPC mixtures very nearly overlay one another, suggesting that the SP-B is being excluded from the film. The use of multiple contrasts with NR at a range of surface pressures has enabled the mixing and 'squeeze out' of the DPPC and SP-B mixtures to be studied. We are able to identify the SP-B component of the interfacial structure and its position as a function of surface pressure. The mixtures are initially a homogeneous layer at low surface pressures. At higher surface pressures the SP-B is squeezed out of the lipid layer into the subphase, with the first signs detected at 30 mN m(-1). At 50 mN m(-1) the subphase is almost completely excluded from the DPPC layer with the SP-B content significantly reduced. Only a small amount of DPPC appears to be associated with the squeezed out SP-B.},
  author       = {Fullagar, Wilfred and Holt, Stephen A and Gentle, Ian R},
  issn         = {1542-0086},
  keyword      = {surfactant protein,squeeze-out,SP-B,pulmonary surfactant,lung surfactant},
  language     = {eng},
  publisher    = {Cell Press},
  series       = {Biophysical Journal},
  title        = {Structure of SP-B/DPPC Mixed Films Studied by Neutron Reflectometry.},
  url          = {http://dx.doi.org/10.1529/biophysj.108.134395},
  volume       = {First Published August 15, 2008},
  year         = {2008},
}