Microstructure and dynamic surface properties of surfactant protein SP-B/dipalmitoylphosphatidylcholine interfacial films spread from lipid-protein bilayers

Cruz, Antonio; Worthman, L.-A.; Serrano, Alicia G.; Casals, Cristina; Keough, K. M. W.; Pérez‐Gil, Jesús

doi:10.1007/pl00006647

Cited by 67 publications

(81 citation statements)

References 36 publications

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“…Planar Supported Phospholipid Layers-Phospholipid monolayers were spread from chloroform/methanol 3:1 (v/v) solutions onto a 5 mM sodium phosphate (pH 7.4), 150 mM NaCl subphase in a thermostatted Langmuir-Blodgett trough (NIMA Technologies, Coventry) as previously described (3,30,31). After 10 min, to allow for solvent evaporation, monolayers were compressed at 25 cm 2 /min up to 32 mN/m and then transferred onto a glass coverslip at 5 mm/min.…”

Section: Methodsmentioning

confidence: 99%

Recognition and Blocking of HIV-1 gp41 Pre-transmembrane Sequence by Monoclonal 4E10 Antibody in a Raft-like Membrane Environment

Lorizate

Cruz

Huarte

et al. 2006

Journal of Biological Chemistry

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Here we demonstrate that the broadly neutralizing 4E10 antibody is able to specifically block the membrane-restructuring activity of a peptide mimic inserted into membranes. Recognition and restructuring blocking occurred in the presence of cholesterol, whereas transmembrane versions as those promoted in 1-palmitoyl-2-oleoylphosphatidylcholine:sphingomyelin mixtures could not be effectively arrested. Spectrofluorimetric assays using rhodamine-labeled peptides revealed that recognition correlated better with pore-formation blocking than with membrane-fusion inhibition. The capacity of the antibody to recognize preTM peptides in a raft-like environment was further corroborated employing planar-supported lipid layers and fluorescence microscopy. These data support that membrane-bound epitope recognition by 4E10 results in clustering reorganization of preTM at the membrane interface. We propose that this process might interfere with the formation of fusion-competent complexes at the low spike densities existing in the HIV-1 membrane. This work comprises the first experimental report on a lipid-modulated antibody capacity to bind a membrane-bound epitope sequence and arrest its restructuring activity.

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Section: Methodsmentioning

confidence: 99%

Recognition and Blocking of HIV-1 gp41 Pre-transmembrane Sequence by Monoclonal 4E10 Antibody in a Raft-like Membrane Environment

Lorizate

Cruz

Huarte

et al. 2006

Journal of Biological Chemistry

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“…This peripheral disposition could be important for the property of SP-B to stabilise surfactant film compressed states [78]. The protein possesses a net positive charge of +7 at a physiological pH, which would facilitate its selective interaction with the fraction of negatively charged phospholipids in surfactants, mainly phosphatidylglycerol [26].…”

Section: Structure-function Relationships Of Sp-bmentioning

confidence: 99%

Synthetic Pulmonary Surfactant Preparations: New Developments and Future Trends

Mingarro¹,

Lukovic²,

Vilar³

et al. 2008

CMC

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Pulmonary surfactant is a lipid-protein complex that coats the interior of the alveoli and enables the lungs to function properly. Upon its synthesis, lung surfactant adsorbs at the interface between the air and the hypophase, a capillary aqueous layer covering the alveoli. By lowering and modulating surface tension during breathing, lung surfactant reduces respiratory work of expansion, and stabilises alveoli against collapse during expiration.Pulmonary surfactant deficiency, or dysfunction, contributes to several respiratory pathologies, such as infant respiratory distress syndrome (IRDS) in premature neonates, and acute respiratory distress syndrome (ARDS) in children and adults. The main clinical exogenous surfactants currently in use to treat some of these pathologies are essentially organic extracts obtained from animal lungs. Although very efficient, natural surfactants bear serious defects: i) they could vary in composition from batch to batch; ii) their production involves relatively high costs, and sources are limited; and iii) they carry a potential risk of transmission of animal infectious agents and the possibility of immunological reaction. All these caveats justify the necessity for a highly controlled synthetic material.In the present review the efforts aimed at new surfactant development, including the modification of existing exogenous surfactants by adding molecules that can enhance their activity, and the progress achieved in the production of completely new preparations, are discussed. Pulmonary surfactant function and dysfunctionThe respiratory surface of lungs constitutes the largest area of the human body exposed to the environment. Efficient gas exchange requires a large enough surface to be continuously exposed to air while minimising the barriers for oxygen and carbon dioxide to diffuse between air and the blood compartment [1]. At the same time, a selection of combined defence mechanisms is required to help keep such an essentially exposed area sterile of potential pathogenic microorganisms. Pulmonary surfactant, a lipid-protein complex produced by the alveolar epithelium of lungs, has been optimised to coordinate two main activities through natural evolution. On the one hand, it stabilises the respiratory surface against physical forces, therefore minimising the work required to maintain the large respiratory surface open to air [2][3][4]. On the other hand, pulmonary surfactant contains elements responsible for establishing a primary innate antipathogenic barrier, essential to ensure an intrinsically low pathogen load in the absence of induced defence mechanisms [5]. Extensive research in the last few decades has revealed some of the molecular mechanisms involved in pulmonary surfactant action. However, the manner in which both the biophysical and defence activities are intermingled and coordinately modulated in the alveolar spaces is now only beginning to be envisioned.Pulmonary surfactant is composed of approximately 90% lipids and 8-10% proteins, although only around 5% ...

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“…Interfacial adsorption of surfactant samples was also followed on a Teflon-made King-Clements-type of surface balance (22), specially designed by Nima (Coventry, UK) (29). The total volume of subphase was 1.5 ml, thermostatized at the indicated temperature, and continuously stirred with a 2 mm-long magnetic bar.…”

Section: Wilhelmy Balance Measurementsmentioning

confidence: 99%

High-throughput evaluation of pulmonary surfactant adsorption and surface film formation

Ravasio

Cruz

Pérez‐Gil

et al. 2008

Journal of Lipid Research

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The assessment of new therapeutic strategies to cure surfactant-associated lung disorders would greatly benefit from assay systems allowing routine evaluations of surfactant functions. We present a method to measure surfactant adsorption kinetics into interfacial air-liquid interfaces based on fluorescence microplate readers. The principle of measurement is simple, robust, and reproducible: Wells of a microtiter plate contain an aqueous solution of a light-absorbing agent. Fluorescence is excited and collected from the top of the wells so that fluorescently labeled surfactant injected into the bulk can be detected only once adsorbed into the air-liquid interface. Mass transfer from the bulk to the interface is achieved by orbital shaking implemented in the plate reader instrument. The method has been tested and validated by using phospholipids or surfactants of different origins, by using albumin as surfactant inhibitor, and by comparison of results with Wilhelmy balance measurements. The method is suited for implementation in high-throughput screening routines for conditions affecting, or improving, surfactant film formation. In contrast to surface tension measurements, our method gives a direct readout of the amount of surfactant adsorbing into the interface, including the functionally important amount of material firmly associating with the interfacial film.-Ravasio, A., A. Cruz, J. Pérez-Gil, and T. Haller. High-throughput evaluation of pulmonary surfactant adsorption and surface film formation. J. Lipid Res. 2008Res. . 49: 2479Res. -2488

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Microstructure and dynamic surface properties of surfactant protein SP-B/dipalmitoylphosphatidylcholine interfacial films spread from lipid-protein bilayers

Cited by 67 publications

References 36 publications

Recognition and Blocking of HIV-1 gp41 Pre-transmembrane Sequence by Monoclonal 4E10 Antibody in a Raft-like Membrane Environment

Recognition and Blocking of HIV-1 gp41 Pre-transmembrane Sequence by Monoclonal 4E10 Antibody in a Raft-like Membrane Environment

Synthetic Pulmonary Surfactant Preparations: New Developments and Future Trends

High-throughput evaluation of pulmonary surfactant adsorption and surface film formation

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