Pulmonary surfactant: phase behavior and function

Piknová, Barbora; Schram, Vincent; Hall, Stephen B.

doi:10.1016/s0959-440x(02)00352-4

Cited by 131 publications

(141 citation statements)

References 62 publications

Supporting

Mentioning

133

Contrasting

Order By: Relevance

“…However, calcium ions affect the structure and biophysical activity of lung surfactant [1,2]. Moreover, calcium is present in the alveolar fluid at a concentration of % 1.8 mm [26].…”

Section: Effect Of Calcium On the Thermotropic Properties Of Kl 4 -Comentioning

confidence: 99%

“…The human lung has an alveolar surface of 50-100 m 2 , which is completely covered with a lipid-protein complex called pulmonary surfactant [1]. The primary role of this material is to prevent collapse of the alveoli during end-expiration, preclude blood fluid transudation into the alveolar spaces, participate in lung defense against inhaled pathogens and toxins, and modulate the function of respiratory inflammatory cells [1][2][3][4].…”

mentioning

confidence: 99%

“…The primary role of this material is to prevent collapse of the alveoli during end-expiration, preclude blood fluid transudation into the alveolar spaces, participate in lung defense against inhaled pathogens and toxins, and modulate the function of respiratory inflammatory cells [1][2][3][4]. The alteration or deficiency of this system leads to respiratory distress.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Physical properties and surface activity of surfactant‐like membranes containing the cationic and hydrophobic peptide KL₄

et al. 2006

View full text Add to dashboard Cite

Surfactant-like membranes containing the 21-residue peptide KLLLL-KLLLLKLLLLKLLLLK (KL 4 ), have been clinically tested as a therapeutic agent for respiratory distress syndrome in premature infants. The aims of this study were to investigate the interactions between the KL 4 peptide and lipid bilayers, and the role of both the lipid composition and KL 4 structure on the surface adsorption activity of KL 4 -containing membranes. We used bilayers of three-component systems [1,2-dipalmitoyl-phosphatidylcholine ⁄ 1-palmitoyl-2-oleoyl-phosphatidylglycerol ⁄ palmitic acid (DPPC ⁄ POPG ⁄ PA) and DPPC ⁄ 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) ⁄ PA] and binary lipid mixtures of DPPC ⁄ POPG and DPPC ⁄ PA to examine the specific interaction of KL 4 with POPG and PA. We found that, at low peptide concentrations, KL 4 adopted a predominantly a-helical secondary structure in POPG-or POPC-containing membranes, and a b-sheet structure in DPPC ⁄ PA vesicles. As the concentration of the peptide increased, KL 4 interconverted to a b-sheet structure in DPPC ⁄ POPG ⁄ PA or DPPC ⁄ POPC ⁄ PA vesicles. Ca 2+ favored a«b interconversion. This conformational flexibility of KL 4 did not influence the surface adsorption activity of KL 4 -containing vesicles. KL 4 showed a concentration-dependent ordering effect on POPG-and POPC-containing membranes, which could be linked to its surface activity. In addition, we found that the physical state of the membrane had a critical role in the surface adsorption process. Our results indicate that the most rapid surface adsorption takes place with vesicles showing well-defined solid ⁄ fluid phase co-existence at temperatures below their gel to fluid phase transition temperature, such as those of DPPC ⁄ POPG ⁄ PA and DPPC ⁄ POPC ⁄ PA. In contrast, more fluid (DPPC ⁄ POPG) or excessively rigid (DPPC ⁄ PA) KL 4 -containing membranes fail in their ability to adsorb rapidly onto and spread at the airwater interface.Abbreviations Bodipy-PC, 2-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-pentanoyl)-1-hexadecanoyl-sn-glycero-3-phosphocholine; DPH, 1,6-diphenyl-1,3,5-hexatriene; DPPC, 1,2-dipalmitoyl-phosphatidylcholine; DSC, differential scanning calorimetry; GUV, giant unilamellar vesicle; PA, palmitic acid; PC, phosphatidylcholine; POPC, 1-palmitoyl-2-oleoyl-phosphatidylcholine; POPG, 1-palmitoyl-2-oleoyl-phosphatidylglycerol; RDS, respiratory distress syndrome; SP-B, surfactant protein B; SP-C, surfactant protein C; T m , gel to fluid phase transition temperature.

show abstract

“…However, calcium ions affect the structure and biophysical activity of lung surfactant [1,2]. Moreover, calcium is present in the alveolar fluid at a concentration of % 1.8 mm [26].…”

Section: Effect Of Calcium On the Thermotropic Properties Of Kl 4 -Comentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Physical properties and surface activity of surfactant‐like membranes containing the cationic and hydrophobic peptide KL₄

et al. 2006

View full text Add to dashboard Cite

show abstract

“…Recent experimental studies have questioned the classical model [12,13]. Yu and Possmayer conclude that there is no evidence of lipid selectivity during the formation of surface films by adsorption.…”

Section: Pulmonary Surfactant Functionalitymentioning

confidence: 99%

Equation of state for a coarse-grained DPPC monolayer at the air/water interface

Adhangale

Gaver

2006

Molecular Physics

View full text Add to dashboard Cite

Pulmonary surfactant, a complex mixture of phospholipids and proteins, secreted by the type II epithelial cells in the lungs, is crucial to reducing the effort required for breathing. A lack of adequate amounts of pulmonary surfactant in underdeveloped lungs of premature infants results in infant respiratory distress syndrome (RDS). Surfactant replacement therapy (SRT) is the approved method of mitigating the effects of RDS. The development of new SRT regimens requires a fundamental understanding of the links between surfactant biochemistry and functionality. We use a coarse-grained (CG) model to predict the surface pressure-surface concentration relationship (equation of state) for pure DPPC, which is a major component of endogenous and synthetic pulmonary surfactant mixtures. We show that the model can be efficiently used to predict the equation of state in excellent agreement with experimental results. We also study the structure of the monolayer as a function of the surface tension of the system. We show that a decrease in the applied surface tension results in an increase in order in the head group region and a decrease in order in the tail region of DPPC. This technique may be useful in the prediction of equations of state for surfactant replacements.

show abstract

“…Early in situ studies demonstrated that at low lung volumes, the alveolar interfacial ␥ is near 1 mN/m (44). However, despite numerous in vitro studies, the manner in which pulmonary surfactant forms films capable of reaching the low ␥s required to stabilize the lung is still not clear (32).…”

mentioning

confidence: 99%

Disparate effects of two phosphatidylcholine binding proteins, C-reactive protein and surfactant protein A, on pulmonary surfactant structure and function

Nag¹,

Rodríguez-Capote²,

Panda³

et al. 2004

American Journal of Physiology-Lung Cellular and Molecular Phys

View full text Add to dashboard Cite

C-reactive protein (CRP) and surfactant protein A (SP-A) are phosphatidylcholine (PC) binding proteins that function in the innate host defense system. We examined the effects of CRP and SP-A on the surface activity of bovine lipid extract surfactant (BLES), a clinically applied modified natural surfactant. CRP inhibited BLES adsorption to form a surface-active film and the film's ability to lower surface tension (γ) to low values near 0 mN/m during surface area reduction. The inhibitory effects of CRP were reversed by phosphorylcholine, a water-soluble CRP ligand. SP-A enhanced BLES adsorption and its ability to lower γ to low values. Small amounts of SP-A blocked the inhibitory effects of CRP. Electron microscopy showed CRP has little effect on the lipid structure of BLES. SP-A altered BLES multilamellar vesicular structure by generating large, loose bilayer structures that were separated by a fuzzy amorphous material, likely SP-A. These studies indicate that although SP-A and CRP both bind PC, there is a difference in the manner in which they interact with surface films.

show abstract

Pulmonary surfactant: phase behavior and function

Cited by 131 publications

References 62 publications

Physical properties and surface activity of surfactant‐like membranes containing the cationic and hydrophobic peptide KL₄

Physical properties and surface activity of surfactant‐like membranes containing the cationic and hydrophobic peptide KL₄

Equation of state for a coarse-grained DPPC monolayer at the air/water interface

Disparate effects of two phosphatidylcholine binding proteins, C-reactive protein and surfactant protein A, on pulmonary surfactant structure and function

Contact Info

Product

Resources

About

Pulmonary surfactant: phase behavior and function

Cited by 131 publications

References 62 publications

Physical properties and surface activity of surfactant‐like membranes containing the cationic and hydrophobic peptide KL4

Physical properties and surface activity of surfactant‐like membranes containing the cationic and hydrophobic peptide KL4

Equation of state for a coarse-grained DPPC monolayer at the air/water interface

Disparate effects of two phosphatidylcholine binding proteins, C-reactive protein and surfactant protein A, on pulmonary surfactant structure and function

Contact Info

Product

Resources

About

Physical properties and surface activity of surfactant‐like membranes containing the cationic and hydrophobic peptide KL₄

Physical properties and surface activity of surfactant‐like membranes containing the cationic and hydrophobic peptide KL₄