Lipid-protein interactions alter line tensions and domain size distributions in lung surfactant monolayers.
Biophys J
; 102(1): 56-65, 2012 Jan 04.
Article
em En
| MEDLINE
| ID: mdl-22225798
ABSTRACT
The size distribution of domains in phase-separated lung surfactant monolayers influences monolayer viscoelasticity and compressibility which, in turn, influence monolayer collapse and set the compression at which the minimum surface tension is reached. The surfactant-specific protein SP-B decreases the mean domain size and polydispersity as shown by fluorescence microscopy. From the images, the line tension and dipole density difference are determined by comparing the measured size distributions with a theory derived by minimizing the free energy associated with the domain energy and mixing entropy. We find that SP-B increases the line tension, dipole density difference, and the compressibility modulus at surface pressures up to the squeeze-out pressure. The increase in line tension due to SP-B indicates the protein avoids domain boundaries due to its solubility in the more fluid regions of the film.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tensoativos
/
Proteínas
/
Proteína B Associada a Surfactante Pulmonar
/
Lipídeos
/
Pulmão
/
Modelos Químicos
Limite:
Humans
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article