scholarly journals A combined action of pulmonary surfactant proteins SP-B and SP-C modulates permeability and dynamics of phospholipid membranes

2011 ◽  
Vol 438 (3) ◽  
pp. 555-564 ◽  
Author(s):  
Elisa Parra ◽  
Lara H. Moleiro ◽  
Ivan López-Montero ◽  
Antonio Cruz ◽  
Francisco Monroy ◽  
...  
Keyword(s):  
Pulmonary Surfactant ◽  
External Medium ◽  
Nile Red ◽  
Lipid Vesicles ◽  
Membrane Lipid ◽  
Structure And Dynamics ◽  
Lipid Dynamics ◽  
Combined Action ◽  
Surface Active ◽  
Pulmonary Surfactant Proteins

Proteins SP-B and SP-C are essential to promote formation of surface-active films at the respiratory interface, but their mechanism of action is still under investigation. In the present study we have analysed the effect of the proteins on the accessibility of native, quasi-native and model surfactant membranes to incorporation of the fluorescent probes Nile Red (permeable) and FM 1-43 (impermeable) into membranes. We have also analysed the effect of single or combined proteins on membrane permeation using the soluble fluorescent dye calcein. The fluorescence of FM 1-43 was always higher in membranes containing SP-B and/or SP-C than in protein-depleted membranes, in contrast with Nile Red which was very similar in all of the materials tested. SP-B and SP-C promoted probe partition with markedly different kinetics. On the other hand, physiological proportions of SP-B and SP-C caused giant oligolamellar vesicles to incorporate FM 1-43 from the external medium into apparently most of the membranes instantaneously. In contrast, oligolamellar pure lipid vesicles appeared to be mainly labelled in the outermost membrane layer. Pure lipidic vesicles were impermeable to calcein, whereas it permeated through membranes containing SP-B and/or SP-C. Vesicles containing only SP-B were stable, but prone to vesicle–vesicle interactions, whereas those containing only SP-C were extremely dynamic, undergoing frequent fluctuations and ruptures. Differential structural effects of proteins on vesicles were confirmed by electron microscopy. These results suggest that SP-B and SP-C have different contributions to inter- and intra-membrane lipid dynamics, and that their combined action could provide unique effects to modulate structure and dynamics of pulmonary surfactant membranes and films.

scholarly journals Pulmonary surfactant proteins A and D are potent endogenous inhibitors of lipid peroxidation and oxidative cellular injury.

2002 ◽  
Vol 277 (50) ◽  
pp. 49090
Author(s):  
James P. Bridges ◽  
Harold W. Davis ◽  
Mamatha Damodarasamy ◽  
Yoshio Kuroki ◽  
Gabriel Howles ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Pulmonary Surfactant ◽  
Surfactant Proteins ◽  
Cellular Injury ◽  
Endogenous Inhibitors ◽  
Pulmonary Surfactant Proteins

Quantitative Analysis of Pulmonary Surfactant Proteins B and C

1995 ◽  
Vol 232 (2) ◽  
pp. 231-237 ◽  
Author(s):  
Martin van Eijk ◽  
Catharina G.M.De Haas ◽  
Henk P. Haagsman
Keyword(s):  
Quantitative Analysis ◽  
Pulmonary Surfactant ◽  
Surfactant Proteins ◽  
Pulmonary Surfactant Proteins

Hydrophobic Pulmonary Surfactant Proteins in Model Lipid Systems

1991 ◽  
pp. 241-252
Author(s):  
K. M. W. Keough ◽  
J. Pérez-Gil ◽  
G. Simatos ◽  
J. Tucker ◽  
K. Nag ◽  
...  
Keyword(s):  
Pulmonary Surfactant ◽  
Surfactant Proteins ◽  
Pulmonary Surfactant Proteins

scholarly journals Correlation of Vesicle Binding and Phospholipid Dynamics with Phospholipase C Activity

2009 ◽  
Vol 284 (24) ◽  
pp. 16099-16107 ◽  
Author(s):  
Mingming Pu ◽  
Xiaomin Fang ◽  
Alfred G. Redfield ◽  
Anne Gershenson ◽  
Mary F. Roberts
Keyword(s):  
Enzyme Activity ◽  
Phospholipase C ◽  
Lateral Diffusion ◽  
Lipid Vesicles ◽  
Membrane Lipid ◽  
Correlation Spectroscopy ◽  
Anionic Phospholipid ◽  
Anionic Phospholipids ◽  
Substrate Analogue ◽  
Nmr Methods

The enzymatic activity of the peripheral membrane protein, phosphatidylinositol-specific phospholipase C (PI-PLC), is increased by nonsubstrate phospholipids with the extent of enhancement tuned by the membrane lipid composition. For Bacillus thuringiensis PI-PLC, a small amount of phosphatidylcholine (PC) activates the enzyme toward its substrate PI; above 0.5 mol fraction PC (XPC), enzyme activity decreases substantially. To provide a molecular basis for this PC-dependent behavior, we used fluorescence correlation spectroscopy to explore enzyme binding to multicomponent lipid vesicles composed of PC and anionic phospholipids (that bind to the active site as substrate analogues) and high resolution field cycling 31P NMR methods to estimate internal correlation times (τc) of phospholipid headgroup motions. PI-PLC binds poorly to pure anionic phospholipid vesicles, but 0.1 XPC significantly enhances binding, increases PI-PLC activity, and slows nanosecond rotational/wobbling motions of both phospholipid headgroups, as indicated by increased τc. PI-PLC activity and phospholipid τc are constant between 0.1 and 0.5 XPC. Above this PC content, PI-PLC has little additional effect on the substrate analogue but further slows the PC τc, a motional change that correlates with the onset of reduced enzyme activity. For PC-rich bilayers, these changes, together with the reduced order parameter and enhanced lateral diffusion of the substrate analogue in the presence of PI-PLC, imply that at high XPC, kinetic inhibition of PI-PLC results from intravesicle sequestration of the enzyme from the bulk of the substrate. Both methodologies provide a detailed view of protein-lipid interactions and can be readily adapted for other peripheral membrane proteins.

scholarly journals Phosphoinositide kinase signaling controls ER-PM cross-talk

2016 ◽  
Vol 27 (7) ◽  
pp. 1170-1180 ◽  
Author(s):  
Deike J. Omnus ◽  
Andrew G. Manford ◽  
Jakob M. Bader ◽  
Scott D. Emr ◽  
Christopher J. Stefan
Keyword(s):  
Cross Talk ◽  
Regulatory System ◽  
Membrane Lipid ◽  
Kinase Signaling ◽  
Membrane Composition ◽  
Membrane Stress ◽  
Lipid Dynamics ◽  
Cellular Integrity ◽  
Normal Cellular Function ◽  
Pi Kinase

Membrane lipid dynamics must be precisely regulated for normal cellular function, and disruptions in lipid homeostasis are linked to the progression of several diseases. However, little is known about the sensory mechanisms for detecting membrane composition and how lipid metabolism is regulated in response to membrane stress. We find that phosphoinositide (PI) kinase signaling controls a conserved PDK-TORC2-Akt signaling cascade as part of a homeostasis network that allows the endoplasmic reticulum (ER) to modulate essential responses, including Ca2+-regulated lipid biogenesis, upon plasma membrane (PM) stress. Furthermore, loss of ER-PM junctions impairs this protective response, leading to PM integrity defects upon heat stress. Thus PI kinase–mediated ER-PM cross-talk comprises a regulatory system that ensures cellular integrity under membrane stress conditions.

scholarly journals The role of surface charge in the interaction of nanoparticles with model pulmonary surfactants

Soft Matter ◽  
2018 ◽  
Vol 14 (28) ◽  
pp. 5764-5774 ◽  
Author(s):  
F. Mousseau ◽  
J.-F. Berret
Keyword(s):  
Surface Charge ◽  
Lipid Bilayers ◽  
Pulmonary Surfactant ◽  
Lipid Vesicles ◽  
Electrostatic Charge ◽  
Supported Lipid Bilayers ◽  
Pulmonary Surfactants ◽  
Inhaled Nanoparticles

Inhaled nanoparticles reaching the respiratory zone in the lungs enter first in contact with the pulmonary surfactant. It is shown here that nanoparticles and lipid vesicles formulated from different surfactant mimetics interact predominantlyviaelectrostatic charge mediated attraction and do not form supported lipid bilayers spontaneously.

Beta-receptors and surface active material flux in fetal lamb lung: female advantage

1987 ◽  
Vol 63 (2) ◽  
pp. 828-833 ◽  
Author(s):  
D. Warburton ◽  
L. Parton ◽  
S. Buckley ◽  
L. Cosico ◽  
T. Saluna
Keyword(s):  
Pulmonary Surfactant ◽  
Binding Capacity ◽  
Active Material ◽  
Degree Polynomial ◽  
Beta Adrenergic ◽  
Female Advantage ◽  
Beta Agonists ◽  
Beta Receptors ◽  
Surface Active ◽  
Surface Active Material

We correlated the ontogeny of pulmonary beta-adrenergic receptors with the onset of surface active material (SAM) flux into tracheal fluid of male and female chronically catheterized fetal lambs. SAM flux began between 0.82 and 0.85 gestation in the females and between 0.85 and 0.89 gestation in the males and matured more rapidly thereafter in the females than in the males (P less than 0.01). beta-Adrenergic receptor binding, using [3H]dihydroalprenolol as the ligand, was saturable, linear, and stereospecific. The order of potency of competitive beta-agonists was isoproterenol greater than norepinephrine greater than epinephrine. The maximal binding capacity (Bmax) of pulmonary beta-receptors approximately doubled between 0.84 and 0.89 gestation, coinciding with the onset of SAM flux. Bmax matured as a third degree polynomial function of gestational age in females (r = 0.9, P less than 0.001) but as a linear function in males (r = 0.8, P less than 0.005). Between 0.86 and 0.93 gestation, Bmax was 1.45-fold greater in females than males (P less than 0.001). The dissociation constant of beta-receptors was not influenced significantly by gender or gestation. We conclude that maturation of pulmonary beta-receptors coincides with the onset of SAM flux in fetal lambs and that both mature more rapidly in females. We speculate that pulmonary beta-receptor maturation and SAM flux are coregulated by hormonal factors. More rapid maturation of pulmonary beta-receptors and SAM flux in females may be a factor in the female advantage with regard to pulmonary surfactant maturation and the survival of premature neonates.

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