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Tang K, Cui X. A Review on Investigating the Interactions between Nanoparticles and the Pulmonary Surfactant Monolayer with Coarse-Grained Molecular Dynamics Method. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:11829-11842. [PMID: 38809819 DOI: 10.1021/acs.langmuir.4c00909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Pulmonary drug delivery has garnered significant attention due to its targeted local lung action, minimal toxic side effects, and high drug utilization. However, the physicochemical properties of inhaled nanoparticles (NPs) used as drug carriers can influence their interactions with the pulmonary surfactant (PS) monolayer, potentially altering the fate of the NPs and impairing the biophysical function of the PS monolayer. Thus, the objective of this review is to summarize how the physicochemical properties of NPs affect their interactions with the PS monolayer. Initially, the definition and properties of NPs, as well as the composition and characteristics of the PS monolayer, are introduced. Subsequently, the coarse-grained molecular dynamics (CGMD) simulation method for studying the interactions between NPs and the PS monolayer is presented. Finally, the implications of the hydrophobicity, size, shape, surface charge, surface modification, and aggregation of NPs on their interactions with the PS monolayer and on the composition of biomolecular corona are discussed. In conclusion, gaining a deeper understanding of the effects of the physicochemical properties of NPs on their interactions with the PS monolayer will contribute to the development of safer and more effective nanomedicines for pulmonary drug delivery.
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Affiliation(s)
- Kailiang Tang
- School of Aerospace Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xinguang Cui
- School of Aerospace Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
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2
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Abstract
Pulmonary surfactant is a critical component of lung function in healthy individuals. It functions in part by lowering surface tension in the alveoli, thereby allowing for breathing with minimal effort. The prevailing thinking is that low surface tension is attained by a compression-driven squeeze-out of unsaturated phospholipids during exhalation, forming a film enriched in saturated phospholipids that achieves surface tensions close to zero. A thorough review of past and recent literature suggests that the compression-driven squeeze-out mechanism may be erroneous. Here, we posit that a surfactant film enriched in saturated lipids is formed shortly after birth by an adsorption-driven sorting process and that its composition does not change during normal breathing. We provide biophysical evidence for the rapid formation of an enriched film at high surfactant concentrations, facilitated by adsorption structures containing hydrophobic surfactant proteins. We examine biophysical evidence for and against the compression-driven squeeze-out mechanism and propose a new model for surfactant function. The proposed model is tested against existing physiological and pathophysiological evidence in neonatal and adult lungs, leading to ideas for biophysical research, that should be addressed to establish the physiological relevance of this new perspective on the function of the mighty thin film that surfactant provides.
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Affiliation(s)
- Fred Possmayer
- Department of Biochemistry, Western University, London, Ontario N6A 3K7, Canada
- Department of Obstetrics/Gynaecology, Western University, London, Ontario N6A 3K7, Canada
| | - Yi Y Zuo
- Department of Mechanical Engineering, University of Hawaii at Manon, Honolulu, Hawaii 96822, United States
- Department of Pediatrics, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96826, United States
| | - Ruud A W Veldhuizen
- Department of Physiology & Pharmacology, Western University, London, Ontario N6A 5C1, Canada
- Department of Medicine, Western University, London, Ontario N6A 3K7, Canada
- Lawson Health Research Institute, London, Ontario N6A 4V2, Canada
| | - Nils O Petersen
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
- Department of Chemistry, Western University, London, Ontario N6A 5B7, Canada
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3
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Abstract
There is an urgent need for physiologically relevant and customizable biochip models of human lung tissue to provide a niche for lung disease modeling and drug efficacy. Although various lung-on-a-chips have been developed, the conventional fabrication method has been limited in reconstituting a very thin and multilayered architecture and spatial arrangements of multiple cell types in a microfluidic device. To overcome these limitations, we developed a physiologically relevant human alveolar lung-on-a-chip model, effectively integrated with an inkjet-printed, micron-thick, and three-layered tissue. After bioprinting lung tissues inside four culture inserts layer-by-layer, the inserts are implanted into a biochip that supplies a flow of culture medium. This modular implantation procedure enables the formation of a lung-on-a-chip to facilitate the culture of 3D-structured inkjet-bioprinted lung models under perfusion at the air-liquid interface. The bioprinted models cultured on the chip maintained their structure with three layers of tens of micrometers and achieved a tight junction in the epithelial layer, the critical properties of an alveolar barrier. The upregulation of genes involved in the essential functions of alveoli was also confirmed in our model. Our culture insert-mountable organ-on-a-chip is a versatile platform that can be applied to various organ models by implanting and replacing culture inserts. It is amenable to mass production and the development of customized models through the convergence with bioprinting technology.
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Affiliation(s)
- Wookyeom Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Yunji Lee
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Dayoon Kang
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Taejeong Kwak
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Hwa-Rim Lee
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Sungjune Jung
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
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4
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Marquardt D, van Oosten B, Dziura M, Long JR, Harroun TA. The interaction and orientation of Peptide KL 4 in model membranes. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183893. [PMID: 35219719 DOI: 10.1016/j.bbamem.2022.183893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 01/18/2022] [Accepted: 02/11/2022] [Indexed: 06/14/2023]
Abstract
We report on the orientation and location of synthetic pulmonary surfactant peptide KL4, (KLLLL)4K, in model lipid membranes. The partitioning depths of selectively deuterated leucine residues within KL4 were determined in DPPC:POPG (4:1) and POPC:POPG (4:1) bilayers by oriented neutron diffraction. These measurements were combined with an NMR-generated model of the peptide structure to determine the orientation and partitioning of the peptide at the lipid-water interface. The results demonstrate KL4 adopting an orientation that interacts with a single membrane leaflet. These observations are consistent with past 2H NMR and EPR studies (Antharam et al., 2009; Turner et al., 2014).
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Affiliation(s)
- Drew Marquardt
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada; Department of Physics, University of Windsor, Windsor, Ontario, Canada.
| | - Brad van Oosten
- Department of Physics, Brock University, St. Catharines, Ontario, Canada
| | - Maksymilian Dziura
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada
| | - Joanna R Long
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, USA
| | - Thad A Harroun
- Department of Physics, Brock University, St. Catharines, Ontario, Canada.
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5
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The lung surfactant activity probed with molecular dynamics simulations. Adv Colloid Interface Sci 2022; 304:102659. [PMID: 35421637 DOI: 10.1016/j.cis.2022.102659] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 03/18/2022] [Accepted: 03/31/2022] [Indexed: 01/17/2023]
Abstract
The surface of pulmonary alveolar subphase is covered with a mixture of lipids and proteins. This lung surfactant plays a crucial role in lung functioning. It shows a complex phase behavior which can be altered by the interaction with third molecules such as drugs or pollutants. For studying multicomponent biological systems, it is of interest to couple experimental approach with computational modelling yielding atomic-scale information. Simple two, three, or four-component model systems showed to be useful for getting more insight in the interaction between lipids, lipids and proteins or lipids and proteins with drugs and impurities. These systems were studied theoretically using molecular dynamic simulations and experimentally by means of the Langmuir technique. A better understanding of the structure and behavior of lung surfactants obtained from this research is relevant for developing new synthetic surfactants for efficient therapies, and may contribute to public health protection.
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6
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Hossain SI, Islam MZ, Saha SC, Deplazes E. Drug Meets Monolayer: Understanding the Interactions of Sterol Drugs with Models of the Lung Surfactant Monolayer Using Molecular Dynamics Simulations. Methods Mol Biol 2022; 2402:103-121. [PMID: 34854039 DOI: 10.1007/978-1-0716-1843-1_9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The lung surfactant monolayer (LSM) is a thin layer of lipids and proteins that forms the air/water interface of the alveoli. The primary function of the LSM is to reduce the surface tension at the air/water interface during breathing. The LSM also forms the main biological barrier for any inhaled particles, including drugs, to treat lung diseases. Elucidating the mechanism by which these drugs bind to and absorb into the LSM requires a molecular-level understanding of any drug-induced changes to the morphology, structure, and phase changes of the LSM.Molecular dynamics simulations have been used extensively to study the structure and dynamics of the LSM. The monolayer is usually simulated in at least two states: the compressed state, mimicking exhalation, and the expanded state, mimicking inhalation. In this chapter, we provide detailed instructions on how to set up, run, and analyze coarse-grained MD simulations to study the concentration-dependent effect of a sterol drug on the LSM, both in the expanded and compressed state.
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Affiliation(s)
- Sheikh I Hossain
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW, Australia
| | - Mohammad Z Islam
- School of Mechanical and Mechatronic Engineering, University of Technology Sydney, Ultimo, NSW, Australia
- Department of Mathematics, Jashore University of Science and Technology, Jashore, Bangladesh
| | - Suvash C Saha
- School of Mechanical and Mechatronic Engineering, University of Technology Sydney, Ultimo, NSW, Australia
| | - Evelyne Deplazes
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW, Australia.
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7
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Bouchoris K, Bontozoglou V. A model of lung surfactant dynamics based on intrinsic interfacial compressibility. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.126839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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8
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Guagliardo R, Herman L, Penders J, Zamborlin A, De Keersmaecker H, Van de Vyver T, Verstraeten S, Merckx P, Mingeot-Leclercq MP, Echaide M, Pérez-Gil J, Stevens MM, De Smedt SC, Raemdonck K. Surfactant Protein B Promotes Cytosolic SiRNA Delivery by Adopting a Virus-like Mechanism of Action. ACS NANO 2021; 15:8095-8109. [PMID: 33724778 DOI: 10.1021/acsnano.0c04489] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
RNA therapeutics are poised to revolutionize medicine. To unlock the full potential of RNA drugs, safe and efficient (nano)formulations to deliver them inside target cells are required. Endosomal sequestration of nanocarriers represents a major bottleneck in nucleic acid delivery. Gaining more detailed information on the intracellular behavior of RNA nanocarriers is crucial to rationally develop delivery systems with improved therapeutic efficiency. Surfactant protein B (SP-B) is a key component of pulmonary surfactant (PS), essential for mammalian breathing. In contrast to the general belief that PS should be regarded as a barrier for inhaled nanomedicines, we recently discovered the ability of SP-B to promote gene silencing by siRNA-loaded and lipid-coated nanogels. However, the mechanisms governing this process are poorly understood. The major objective of this work was to obtain mechanistic insights into the SP-B-mediated cellular delivery of siRNA. To this end, we combined siRNA knockdown experiments, confocal microscopy, and focused ion beam scanning electron microscopy imaging in an in vitro non-small-cell lung carcinoma model with lipid mixing assays on vesicles that mimic the composition of (intra)cellular membranes. Our work highlights a strong correlation between SP-B-mediated fusion with anionic endosomal membranes and cytosolic siRNA delivery, a mode of action resembling that of certain viruses and virus-derived cell-penetrating peptides. Building on these gained insights, we optimized the SP-B proteolipid composition, which dramatically improved delivery efficiency. Altogether, our work provides a mechanistic understanding of SP-B-induced perturbation of intracellular membranes, offering opportunities to fuel the rational design of SP-B-inspired RNA nanoformulations for inhalation therapy.
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Affiliation(s)
- Roberta Guagliardo
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Lore Herman
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Jelle Penders
- Department of Materials, Department of Bioengineering and Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, U.K
| | - Agata Zamborlin
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Herlinde De Keersmaecker
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
- Centre for Advanced Light Microscopy, Ghent University, 9000 Ghent, Belgium
| | - Thijs Van de Vyver
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Sandrine Verstraeten
- Université Catholique de Louvain, Louvain Drug Research Institute, Pharmacologie Cellulaire et Moléculaire, Avenue E. Mounier 73, UCL B1.73.05, 1200 Brussels, Belgium
| | - Pieterjan Merckx
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Marie-Paule Mingeot-Leclercq
- Université Catholique de Louvain, Louvain Drug Research Institute, Pharmacologie Cellulaire et Moléculaire, Avenue E. Mounier 73, UCL B1.73.05, 1200 Brussels, Belgium
| | - Mercedes Echaide
- Departamento de Bioquímica y Biología Molecular, Facultad de Biologia, and Research Institute Hospital 12 de Octubre, Universidad Complutense, José Antonio Novais 12, 28040 Madrid, Spain
| | - Jesús Pérez-Gil
- Departamento de Bioquímica y Biología Molecular, Facultad de Biologia, and Research Institute Hospital 12 de Octubre, Universidad Complutense, José Antonio Novais 12, 28040 Madrid, Spain
| | - Molly M Stevens
- Department of Materials, Department of Bioengineering and Institute of Biomedical Engineering, Imperial College London, London SW7 2AZ, U.K
| | - Stefaan C De Smedt
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Koen Raemdonck
- Ghent Research Group on Nanomedicines, Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
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9
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Structural hallmarks of lung surfactant: Lipid-protein interactions, membrane structure and future challenges. Arch Biochem Biophys 2021; 703:108850. [PMID: 33753033 DOI: 10.1016/j.abb.2021.108850] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 02/20/2021] [Accepted: 03/16/2021] [Indexed: 11/23/2022]
Abstract
Lung surfactant (LS) is an outstanding example of how a highly regulated and dynamic membrane-based system has evolved to sustain a wealth of structural reorganizations in order to accomplish its biophysical function, as it coats and stabilizes the respiratory air-liquid interface in the mammalian lung. The present review dissects the complexity of the structure-function relationships in LS through an updated description of the lipid-protein interactions and the membrane structures that sustain its synthesis, secretion, interfacial performance and recycling. We also revise the current models and the biophysical techniques employed to study the membranous architecture of LS. It is important to consider that the structure and functional properties of LS are often studied in bulk or under static conditions, in spite that surfactant function is strongly connected with a highly dynamic behaviour, sustained by very polymorphic structures and lipid-lipid, lipid-protein and protein-protein interactions that reorganize in precise spatio-temporal coordinates. We have tried to underline the evidences available of the existence of such structural dynamism in LS. A last important aspect is that the synthesis and assembly of LS is a strongly regulated intracellular process to ensure the establishment of the proper interactions driving LS surface activity, while protecting the integrity of other cell membranes. The use of simplified lipid models or partial natural materials purified from animal tissues could be too simplistic to understand the true molecular mechanisms defining surfactant function in vivo. In this line, we will bring into the attention of the reader the methodological challenges and the questions still open to understand the structure-function relationships of LS at its full biological relevance.
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10
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Hossain SI, Gandhi NS, Hughes ZE, Saha SC. Computational Studies of Lipid-Wrapped Gold Nanoparticle Transport Through Model Lung Surfactant Monolayers. J Phys Chem B 2021; 125:1392-1401. [PMID: 33529013 DOI: 10.1021/acs.jpcb.0c09518] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Colloidal nanoparticles, such as gold nanoparticles (AuNPs), are promising materials for the delivery of hydrophilic drugs via the pulmonary route. The inhaled nanoparticle drug carriers primarily deposit in lung alveoli and interact with the alveolar surface known as lung surfactants. Therefore, it is vital to understand the interactions of nanocarriers with the surfactant layer. To understand the interactions at the molecular level, here we simulated model lung surfactant monolayers with phospholipid (PL)-wrapped AuNPs at the vacuum-water interface using coarse-grained molecular dynamics simulations. The PL-wrapped AuNPs quickly adsorbed into the surfactant layer, altered the structural properties of the monolayer, and at high concentrations initiated the compressed monolayer to collapse/buckle. Among the surfactant monolayer lipid components, cholesterol adsorbed to the AuNPs preferentially over PL species. The position of the adsorbed PL-AuNPs within the monolayer, and subsequent monolayer perturbation, vary depending on the monolayer phase, monolayer composition, and species of PL used as a ligand. Information provided by these molecular dynamic simulations helps to rationalize why some colloidal nanoparticles work better as nanocarriers than others and aid the design of new ones, to avoid biological toxicity and improve efficacy for pulmonary drug delivery.
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Affiliation(s)
- Sheikh I Hossain
- School of Mechanical and Mechatronic Engineering, University of Technology Sydney, 81 Broadway, Ultimo, New South Wales 2007, Australia
| | - Neha S Gandhi
- School of Chemistry and Physics, Faculty of Science and Centre for Genomics and Personalised Health, Queensland University of Technology, 2 George Street, GP.O. Box 2434, Brisbane, Queensland 4000, Australia
| | - Zak E Hughes
- School of Chemistry and Biosciences, The University of Bradford, Bradford BD7 1DP, U.K
| | - Suvash C Saha
- School of Mechanical and Mechatronic Engineering, University of Technology Sydney, 81 Broadway, Ultimo, New South Wales 2007, Australia
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11
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Liekkinen J, de Santos Moreno B, Paananen RO, Vattulainen I, Monticelli L, Bernardino de la Serna J, Javanainen M. Understanding the Functional Properties of Lipid Heterogeneity in Pulmonary Surfactant Monolayers at the Atomistic Level. Front Cell Dev Biol 2020; 8:581016. [PMID: 33304898 PMCID: PMC7701215 DOI: 10.3389/fcell.2020.581016] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 10/16/2020] [Indexed: 01/11/2023] Open
Abstract
Pulmonary surfactant is a complex mixture of lipids and proteins lining the interior of the alveoli, and constitutes the first barrier to both oxygen and pathogens as they progress toward blood circulation. Despite decades of study, the behavior of the pulmonary surfactant at the molecular scale is poorly understood, which hinders the development of effective surfactant replacement therapies, useful in the treatment of several lung-related diseases. In this work, we combined all-atom molecular dynamics simulations, Langmuir trough measurements, and AFM imaging to study synthetic four-component lipid monolayers designed to model protein-free pulmonary surfactant. We characterized the structural and dynamic properties of the monolayers with a special focus on lateral heterogeneity. Remarkably, simulations reproduce almost quantitatively the experimental data on pressure-area isotherms and the presence of lateral heterogeneities highlighted by AFM. Quite surprisingly, the pressure-area isotherms do not show a plateau region, despite the presence of liquid-condensed nanometer-sized domains at surface pressures larger than 20 mN/m. In the simulations, the liquid-condensed domains were small and transient, but they did not coalesce to yield a separate phase. They were only slightly enriched in DPPC and cholesterol, and their chemical composition remained very similar to the overall composition of the monolayer membrane. Instead, they differed from liquid-expanded regions in terms of membrane thickness (in agreement with AFM data), diffusion rates, as well as acyl chain packing and orientation. We hypothesize that such lateral heterogeneities are crucial for lung surfactant function, as they allow both efficient packing, to achieve low surface tension, and sufficient fluidity, critical for rapid adsorption to the air–liquid interface during the breathing cycle.
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Affiliation(s)
- Juho Liekkinen
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Berta de Santos Moreno
- National Heart & Lung Institute, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Riku O Paananen
- Helsinki Eye Lab, Ophthalmology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Ilpo Vattulainen
- Department of Physics, University of Helsinki, Helsinki, Finland.,Computational Physics Laboratory, Tampere University, Tampere, Finland.,MEMPHYS - Centre for Biomembrane Physics, Odense, Denmark
| | - Luca Monticelli
- Molecular Microbiology and Structural Biochemistry (MMSB), UMR 5086 CNRS & University of Lyon, Lyon, France
| | | | - Matti Javanainen
- Computational Physics Laboratory, Tampere University, Tampere, Finland.,Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czechia
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12
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Martínez-Calle M, Parra-Ortiz E, Cruz A, Olmeda B, Pérez-Gil J. Towards the Molecular Mechanism of Pulmonary Surfactant Protein SP-B: At the Crossroad of Membrane Permeability and Interfacial Lipid Transfer. J Mol Biol 2020; 433:166749. [PMID: 33309854 DOI: 10.1016/j.jmb.2020.166749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/14/2020] [Accepted: 12/03/2020] [Indexed: 11/17/2022]
Abstract
Pulmonary surfactant is a lipid-protein complex that coats the alveolar air-liquid interface, enabling the proper functioning of lung mechanics. The hydrophobic surfactant protein SP-B, in particular, plays an indispensable role in promoting the rapid adsorption of phospholipids into the interface. For this, formation of SP-B ring-shaped assemblies seems to be important, as oligomerization could be required for the ability of the protein to generate membrane contacts and to mediate lipid transfer among surfactant structures. SP-B, together with the other hydrophobic surfactant protein SP-C, also promotes permeability of surfactant membranes to polar molecules although the molecular mechanisms underlying this property, as well as its relevance for the surface activity of the protein, remain undefined. In this work, the contribution of SP-B and SP-C to surfactant membrane permeability has been further investigated, by evaluation of the ability of differently-sized fluorescent polar probes to permeate through giant vesicles with different lipid/protein composition. Our results are consistent with the generation by SP-B of pores with defined size in surfactant membranes. Furthermore, incubation of surfactant with an anti-SP-B antibody not only blocked membrane permeability but also affected lipid transfer into the air-water interface, as observed in a captive bubble surfactometer device. Our findings include the identification of SP-C and anionic phospholipids as modulators required for maintaining native-like permeability features in pulmonary surfactant membranes. Proper permeability through membrane assemblies could be crucial to complement the overall role of surfactant in maintaining alveolar equilibrium, beyond its biophysical function in stabilizing the respiratory air-liquid interface.
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Affiliation(s)
- Marta Martínez-Calle
- Department of Biochemistry, Faculty of Biology, Complutense University, Madrid, Spain; Research Institute "Hospital 12 de Octubre (imas12)", Complutense University, Madrid, Spain
| | - Elisa Parra-Ortiz
- Department of Biochemistry, Faculty of Biology, Complutense University, Madrid, Spain
| | - Antonio Cruz
- Department of Biochemistry, Faculty of Biology, Complutense University, Madrid, Spain; Research Institute "Hospital 12 de Octubre (imas12)", Complutense University, Madrid, Spain
| | - Barbara Olmeda
- Department of Biochemistry, Faculty of Biology, Complutense University, Madrid, Spain; Research Institute "Hospital 12 de Octubre (imas12)", Complutense University, Madrid, Spain.
| | - Jesús Pérez-Gil
- Department of Biochemistry, Faculty of Biology, Complutense University, Madrid, Spain; Research Institute "Hospital 12 de Octubre (imas12)", Complutense University, Madrid, Spain
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13
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Oseliero Filho PL, Gerbelli BB, Fornasier F, Chaves Filho AB, Yoshinaga MY, Miyamoto S, Mortara L, Lacerda CD, Cuccovia IM, Pimentel AS, Oliveira CLP. Structure and Thermotropic Behavior of Bovine- and Porcine-Derived Exogenous Lung Surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:14514-14529. [PMID: 33210931 DOI: 10.1021/acs.langmuir.0c02224] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Two commercial exogenous pulmonary surfactants, Curosurf and Survanta, are investigated. Their thermotropic behavior and associated structural changes for the samples in bulk are characterized and described. For Survanta, the obtained results of differential scanning calorimetry showed a thermogram with three peaks on heating and only a single peak on cooling. Curosurf on the other hand, presents calorimetric thermograms with only one peak in both the heating and cooling scans. This distinct thermotropic behavior between the two pulmonary surfactants, a consequence of their particular compositions, is associated with structural changes that were evaluated by simultaneous small- and wide-angle X-ray scattering experiments with in situ temperature variation. Interestingly, for temperatures below ∼35 °C for Curosurf and ∼53 °C for Survanta, the scattering data indicated the coexistence of two lamellar phases with different carbon chain organizations. For temperatures above these limits, the coexistence of phases disappears, giving rise to a fluid phase in both pulmonary surfactants, with multilamelar vesicles for Curosurf and unilamellar vesicles for Survanta. This process is quasi-reversible under cooling, and advanced data analysis for the scattering data indicated differences in the structural and elastic properties of the pulmonary surfactants. The detailed and systematic investigation shown in this work expands on the knowledge of the structure and thermodynamic behavior of Curosurf and Survanta, being relevant from both physiological and biophysical perspectives and also providing a basis for further studies on other types of pulmonary surfactants.
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Affiliation(s)
| | - Barbara Bianca Gerbelli
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, SP 09210-580, Brazil
| | - Franccesca Fornasier
- Departamento de Química, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, RJ 22453-900, Brazil
| | - Adriano B Chaves Filho
- Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes, Butantã, São Paulo, SP 05508-000, Brazil
| | - Marcos Yukio Yoshinaga
- Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes, Butantã, São Paulo, SP 05508-000, Brazil
| | - Sayuri Miyamoto
- Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes, Butantã, São Paulo, SP 05508-000, Brazil
| | - Laura Mortara
- Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes, Butantã, São Paulo, SP 05508-000, Brazil
| | - Caroline Dutra Lacerda
- Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes, Butantã, São Paulo, SP 05508-000, Brazil
| | - Iolanda Midea Cuccovia
- Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes, Butantã, São Paulo, SP 05508-000, Brazil
| | - André Silva Pimentel
- Departamento de Química, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro, RJ 22453-900, Brazil
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14
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Souza LM, Souza FR, Reynaud F, Pimentel AS. Tuning the hydrophobicity of a coarse grained model of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine using the experimental octanol-water partition coefficient. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.114132] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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15
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Loney RW, Panzuela S, Chen J, Yang Z, Fritz JR, Dell Z, Corradi V, Kumar K, Tieleman DP, Hall SB, Tristram-Nagle SA. Location of the Hydrophobic Surfactant Proteins, SP-B and SP-C, in Fluid-Phase Bilayers. J Phys Chem B 2020; 124:6763-6774. [PMID: 32600036 DOI: 10.1021/acs.jpcb.0c03665] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The hydrophobic surfactant proteins, SP-B and SP-C, promote rapid adsorption by the surfactant lipids to the surface of the liquid that lines the alveolar air sacks of the lungs. To gain insights into the mechanisms of their function, we used X-ray diffuse scattering (XDS) and molecular dynamics (MD) simulations to determine the location of SP-B and SP-C within phospholipid bilayers. Initial samples contained the surfactant lipids from extracted calf surfactant with increasing doses of the proteins. XDS located protein density near the phospholipid headgroup and in the hydrocarbon core, presumed to be SP-B and SP-C, respectively. Measurements on dioleoylphosphatidylcholine (DOPC) with the proteins produced similar results. MD simulations of the proteins with DOPC provided molecular detail and allowed direct comparison of the experimental and simulated results. Simulations used conformations of SP-B based on other members of the saposin-like family, which form either open or closed V-shaped structures. For SP-C, the amino acid sequence suggests a partial α-helix. Simulations fit best with measurements of XDS for closed SP-B, which occurred at the membrane surface, and SP-C oriented along the hydrophobic interior. Our results provide the most definitive evidence yet concerning the location and orientation of the hydrophobic surfactant proteins.
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Affiliation(s)
- Ryan W Loney
- Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - Sergio Panzuela
- Centre for Molecular Simulation and Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada.,Department of Theoretical Physics and Condensed Matter, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Jespar Chen
- Biological Physics Group, Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Zimo Yang
- Biological Physics Group, Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Jonathan R Fritz
- Biological Physics Group, Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Zachary Dell
- Biological Physics Group, Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Valentina Corradi
- Centre for Molecular Simulation and Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Kamlesh Kumar
- Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - D Peter Tieleman
- Centre for Molecular Simulation and Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Stephen B Hall
- Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - Stephanie A Tristram-Nagle
- Biological Physics Group, Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
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16
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Lipid-Protein and Protein-Protein Interactions in the Pulmonary Surfactant System and Their Role in Lung Homeostasis. Int J Mol Sci 2020; 21:ijms21103708. [PMID: 32466119 PMCID: PMC7279303 DOI: 10.3390/ijms21103708] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 05/22/2020] [Accepted: 05/22/2020] [Indexed: 12/12/2022] Open
Abstract
Pulmonary surfactant is a lipid/protein complex synthesized by the alveolar epithelium and secreted into the airspaces, where it coats and protects the large respiratory air–liquid interface. Surfactant, assembled as a complex network of membranous structures, integrates elements in charge of reducing surface tension to a minimum along the breathing cycle, thus maintaining a large surface open to gas exchange and also protecting the lung and the body from the entrance of a myriad of potentially pathogenic entities. Different molecules in the surfactant establish a multivalent crosstalk with the epithelium, the immune system and the lung microbiota, constituting a crucial platform to sustain homeostasis, under health and disease. This review summarizes some of the most important molecules and interactions within lung surfactant and how multiple lipid–protein and protein–protein interactions contribute to the proper maintenance of an operative respiratory surface.
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17
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Liekkinen J, Enkavi G, Javanainen M, Olmeda B, Pérez-Gil J, Vattulainen I. Pulmonary Surfactant Lipid Reorganization Induced by the Adsorption of the Oligomeric Surfactant Protein B Complex. J Mol Biol 2020; 432:3251-3268. [DOI: 10.1016/j.jmb.2020.02.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 02/22/2020] [Accepted: 02/24/2020] [Indexed: 12/11/2022]
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18
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Hossain SI, Gandhi NS, Hughes ZE, Saha SC. The role of SP-B1–25 peptides in lung surfactant monolayers exposed to gold nanoparticles. Phys Chem Chem Phys 2020; 22:15231-15241. [DOI: 10.1039/d0cp00268b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lung surfactant monolayer’s (acts as the first line barrier for inhaled nanoparticles) components (lipids and peptides) rearrange themselves by the influence of exposed gold nanoparticles at various stages of the breathing cycle.
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Affiliation(s)
- Sheikh I. Hossain
- School of Mechanical and Mechatronic Engineering
- University of Technology Sydney
- 81 Broadway
- Ultimo
- Australia
| | - Neha S. Gandhi
- School of Mathematical Sciences, Queensland University of Technology
- 2 George Street
- GPO Box 2434
- Brisbane
- Australia
| | - Zak E. Hughes
- School of Chemistry and Biosciences
- The University of Bradford
- Bradford
- UK
| | - Suvash C. Saha
- School of Mechanical and Mechatronic Engineering
- University of Technology Sydney
- 81 Broadway
- Ultimo
- Australia
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19
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Permeation of beta-defensin-3 encapsulated with polyethylene glycol in lung surfactant models at air-water interface. Colloids Surf B Biointerfaces 2019; 182:110357. [DOI: 10.1016/j.colsurfb.2019.110357] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 07/07/2019] [Accepted: 07/08/2019] [Indexed: 11/21/2022]
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20
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Bai X, Xu L, Tang JY, Zuo YY, Hu G. Adsorption of Phospholipids at the Air-Water Surface. Biophys J 2019; 117:1224-1233. [PMID: 31519299 DOI: 10.1016/j.bpj.2019.08.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 08/03/2019] [Accepted: 08/19/2019] [Indexed: 11/15/2022] Open
Abstract
Phospholipids are ubiquitous components of biomembranes and common biomaterials used in many bioengineering applications. Understanding adsorption of phospholipids at the air-water surface plays an important role in the study of pulmonary surfactants and cell membranes. To date, however, the biophysical mechanisms of phospholipid adsorption are still unknown. It is challenging to reveal the molecular structure of adsorbed phospholipid films. Using combined experiments with constrained drop surfactometry and molecular dynamics simulations, here, we studied the biophysical mechanisms of dipalmitoylphosphatidylcholine (DPPC) adsorption at the air-water surface. It was found that the DPPC film adsorbed from vesicles showed distinct equilibrium surface tensions from the DPPC monolayer spread via organic solvents. Our simulations revealed that only the outer leaflet of the DPPC vesicle is capable of unzipping and spreading at the air-water surface, whereas the inner leaflet remains intact and forms an inverted micelle to the interfacial monolayer. This inverted micelle increases the local curvature of the monolayer, thus leading to a loosely packed monolayer at the air-water surface and hence a higher equilibrium surface tension. These findings provide novel insights, to our knowledge, into the mechanism of the phospholipid and pulmonary surfactant adsorption and may help understand the structure-function correlation in biomembranes.
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Affiliation(s)
- Xuan Bai
- Department of Engineering Mechanics, Zhejiang University, Hangzhou, China; The State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China; School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
| | - Lu Xu
- Department of Mechanical Engineering, University of Hawaii at Manoa, Honolulu, Hawaii
| | - Jenny Y Tang
- Department of Mechanical Engineering, University of Hawaii at Manoa, Honolulu, Hawaii
| | - Yi Y Zuo
- Department of Mechanical Engineering, University of Hawaii at Manoa, Honolulu, Hawaii; Department of Pediatrics, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii.
| | - Guoqing Hu
- Department of Engineering Mechanics, Zhejiang University, Hangzhou, China.
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21
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Robichaud NAS, Khatami MH, Saika-Voivod I, Booth V. All-Atom Molecular Dynamics Simulations of Dimeric Lung Surfactant Protein B in Lipid Multilayers. Int J Mol Sci 2019; 20:ijms20163863. [PMID: 31398818 PMCID: PMC6719169 DOI: 10.3390/ijms20163863] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/29/2019] [Accepted: 08/06/2019] [Indexed: 02/07/2023] Open
Abstract
Although lung surfactant protein B (SP-B) is an essential protein that plays a crucial role in breathing, the details of its structure and mechanism are not well understood. SP-B forms covalent homodimers, and in this work we use all-atom molecular dynamics simulations to study dimeric SP-B’s structure and its behavior in promoting lipid structural transitions. Four initial system configurations were constructed based on current knowledge of SP-B’s structure and mechanism, and the protein maintained a helicity consistent with experiment in all systems. Several SP-B-induced lipid reorganization behaviors were observed, and regions of the protein particularly important for these activities included SP-B’s “central loop” and “hinge” regions. SP-B dimers with one subunit initially positioned in each of two adjacent bilayers appeared to promote close contact between two bilayers. When both subunits were initially positioned in the same bilayer, SP-B induced the formation of a defect in the bilayer, with water penetrating into the centre of the bilayer. Similarly, dimeric SP-B showed a propensity to interact with preformed interpores in the bilayer. SP-B dimers also promoted bilayer thinning and creasing. This work fleshes out the atomistic details of the dimeric SP-B structures and SP-B/lipid interactions that underlie SP-B’s essential functions.
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Affiliation(s)
- Nicholas A S Robichaud
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, NL A1B 3X7, Canada
| | - Mohammad Hassan Khatami
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, NL A1B 3X7, Canada
| | - Ivan Saika-Voivod
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, NL A1B 3X7, Canada.
| | - Valerie Booth
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, NL A1B 3X7, Canada.
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada.
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22
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Baer B, Souza LMP, Pimentel AS, Veldhuizen RA. New insights into exogenous surfactant as a carrier of pulmonary therapeutics. Biochem Pharmacol 2019; 164:64-73. [DOI: 10.1016/j.bcp.2019.03.036] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 03/26/2019] [Indexed: 01/03/2023]
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23
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Muller MP, Jiang T, Sun C, Lihan M, Pant S, Mahinthichaichan P, Trifan A, Tajkhorshid E. Characterization of Lipid-Protein Interactions and Lipid-Mediated Modulation of Membrane Protein Function through Molecular Simulation. Chem Rev 2019; 119:6086-6161. [PMID: 30978005 PMCID: PMC6506392 DOI: 10.1021/acs.chemrev.8b00608] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The cellular membrane constitutes one of the most fundamental compartments of a living cell, where key processes such as selective transport of material and exchange of information between the cell and its environment are mediated by proteins that are closely associated with the membrane. The heterogeneity of lipid composition of biological membranes and the effect of lipid molecules on the structure, dynamics, and function of membrane proteins are now widely recognized. Characterization of these functionally important lipid-protein interactions with experimental techniques is however still prohibitively challenging. Molecular dynamics (MD) simulations offer a powerful complementary approach with sufficient temporal and spatial resolutions to gain atomic-level structural information and energetics on lipid-protein interactions. In this review, we aim to provide a broad survey of MD simulations focusing on exploring lipid-protein interactions and characterizing lipid-modulated protein structure and dynamics that have been successful in providing novel insight into the mechanism of membrane protein function.
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Affiliation(s)
- Melanie P. Muller
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- College of Medicine
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Tao Jiang
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Chang Sun
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Muyun Lihan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Shashank Pant
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Paween Mahinthichaichan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Anda Trifan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Emad Tajkhorshid
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- College of Medicine
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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24
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Enami S, Colussi AJ. OH-Radical Oxidation of Lung Surfactant Protein B on Aqueous Surfaces. Mass Spectrom (Tokyo) 2018; 7:S0077. [PMID: 30533342 PMCID: PMC6245955 DOI: 10.5702/massspectrometry.s0077] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 10/11/2018] [Indexed: 11/23/2022] Open
Abstract
Air pollutants generate reactive oxygen species on lung surfaces. Here we report how hydroxyl radicals (·OH) injected on the surface of water react with SP-B1-25, a 25-residue polypeptide surrogate of human lung surfactant protein B. Our experiments consist of intersecting microjets of aqueous SP-B1-25 solutions with O3/O2/H2O/N2(g) gas streams that are photolyzed into ·OH(g) in situ by 266 nm laser nanosecond pulses. Surface-sensitive mass spectrometry enables us to monitor the prompt (<10 μs) and simultaneous formation of primary O n -containing products/intermediates (n≤5) triggered by the reaction of ·OH with interfacial SP-B1-25. We found that O-atoms from both O3 and ·OH are incorporated into the reactive cysteine Cys8 and Cys11 and tryptophan Trp9 components of the hydrophobic N-terminus of SP-B1-25 that lies at the topmost layers of the air-liquid interface. Remarkably, these processes are initiated by ·OH additions rather than by H-atom abstractions from S-H, C-H, or N-H groups. By increasing the hydrophilicity of the N-terminus region of SP-B1-25, these transformations will impair its role as a surfactant.
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Affiliation(s)
| | - Agustín J Colussi
- Linde Center for Global Environmental Science, California Institute of Technology
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25
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Xu Y, Li S, Luo Z, Ren H, Zhang X, Huang F, Zuo YY, Yue T. Role of Lipid Coating in the Transport of Nanodroplets across the Pulmonary Surfactant Layer Revealed by Molecular Dynamics Simulations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:9054-9063. [PMID: 29985617 DOI: 10.1021/acs.langmuir.8b01547] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Hydrophilic drugs can be delivered into lungs via nebulization for both local and systemic therapies. Once inhaled, ultrafine nanodroplets preferentially deposit in the alveolar region, where they first interact with the pulmonary surfactant (PS) layer, with nature of the interaction determining both efficiency of the pulmonary drug delivery and extent of the PS perturbation. Here, we demonstrate by molecular dynamics simulations the transport of nanodroplets across the PS layer being improved by lipid coating. In the absence of lipids, bare nanodroplets deposit at the PS layer to release drugs that can be directly translocated across the PS layer. The translocation is quicker under higher surface tensions but at the cost of opening pores that disrupt the ultrastructure of the PS layer. When the PS layer is compressed to lower surface tensions, the nanodroplet prompts collapse of the PS layer to induce severe PS perturbation. By coating the nanodroplet with lipids, the disturbance of the nanodroplet on the PS layer can be reduced. Moreover, the lipid-coated nanodroplet can be readily wrapped by the PS layer to form vesicular structures, which are expected to fuse with the cell membrane to release drugs into secondary organs. Properties of drug bioavailability, controlled drug release, and enzymatic tolerance in real systems could be improved by lipid coating on nanodroplets. Our results provide useful guidelines for the molecular design of nanodroplets as carriers for the pulmonary drug delivery.
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Affiliation(s)
- Yan Xu
- State Key Laboratory of Heavy Oil Processing, Center for Bioengineering and Biotechnology, College of Chemical Engineering , China University of Petroleum (East China) , Qingdao 266580 , China
| | - Shixin Li
- State Key Laboratory of Heavy Oil Processing, Center for Bioengineering and Biotechnology, College of Chemical Engineering , China University of Petroleum (East China) , Qingdao 266580 , China
| | - Zhen Luo
- State Key Laboratory of Heavy Oil Processing, Center for Bioengineering and Biotechnology, College of Chemical Engineering , China University of Petroleum (East China) , Qingdao 266580 , China
| | - Hao Ren
- State Key Laboratory of Heavy Oil Processing, Center for Bioengineering and Biotechnology, College of Chemical Engineering , China University of Petroleum (East China) , Qingdao 266580 , China
| | - Xianren Zhang
- State Key Laboratory of Organic-Inorganic Composites , Beijing University of Chemical Technology , Beijing 100029 , China
| | - Fang Huang
- State Key Laboratory of Heavy Oil Processing, Center for Bioengineering and Biotechnology, College of Chemical Engineering , China University of Petroleum (East China) , Qingdao 266580 , China
| | - Yi Y Zuo
- Department of Mechanical Engineering , University of Hawaii at Manoa , Honolulu , Hawaii 96822 , United States
- Department of Pediatrics, John A. Burns School of Medicine , University of Hawaii , Honolulu , Hawaii 96826 , United States
| | - Tongtao Yue
- State Key Laboratory of Heavy Oil Processing, Center for Bioengineering and Biotechnology, College of Chemical Engineering , China University of Petroleum (East China) , Qingdao 266580 , China
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26
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Javanainen M, Lamberg A, Cwiklik L, Vattulainen I, Ollila OHS. Atomistic Model for Nearly Quantitative Simulations of Langmuir Monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:2565-2572. [PMID: 28945973 DOI: 10.1021/acs.langmuir.7b02855] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Lung surfactant and a tear film lipid layer are examples of biologically relevant macromolecular structures found at the air-water interface. Because of their complexity, they are often studied in terms of simplified lipid layers, the simplest example being a Langmuir monolayer. Given the profound biological significance of these lipid assemblies, there is a need to understand their structure and dynamics on the nanoscale, yet there are not many techniques able to provide this information. Atomistic molecular dynamics simulations would be a tool fit for this purpose; however, the simulation models suggested until now have been qualitative instead of quantitative. This limitation has mainly stemmed from the challenge to correctly describe the surface tension of water with simulation parameters compatible with other biomolecules. In this work, we show that this limitation can be overcome by using the recently introduced four-point OPC water model, whose surface tension for water is demonstrated to be quantitatively consistent with experimental data and which is also shown to be compatible with the commonly employed lipid models. We further establish that the approach of combining the OPC four-point water model with the CHARMM36 lipid force field provides nearly quantitative agreement with experiments for the surface pressure-area isotherm for POPC and DPPC monolayers, also including the experimentally observed phase coexistence in a DPPC monolayer. The simulation models reported in this work pave the way for nearly quantitative atomistic studies of lipid-rich biological structures at air-water interfaces.
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Affiliation(s)
- Matti Javanainen
- Laboratory of Physics, Tampere University of Technology , 33101 Tampere, Finland
| | | | - Lukasz Cwiklik
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , 182 23 Prague 8, Czech Republic
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences , 166 10 Prague 6, Czech Republic
| | - Ilpo Vattulainen
- Laboratory of Physics, Tampere University of Technology , 33101 Tampere, Finland
- MEMPHYS - Center for Biomembrane Physics, www.memphys.dk
| | - O H Samuli Ollila
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences , 166 10 Prague 6, Czech Republic
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27
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Yue T, Xu Y, Li S, Luo Z, Zhang X, Huang F. Surface patterning of single-walled carbon nanotubes enhances their perturbation on a pulmonary surfactant monolayer: frustrated translocation and bilayer vesiculation. RSC Adv 2017. [DOI: 10.1039/c7ra01392b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In contrast to SWCNTs with unique surface properties, the surface patterning of SWCNTs is found to enhance their perturbation on the pulmonary surfactantsviafrustrated translocation and destructive bilayer vesiculation.
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Affiliation(s)
- Tongtao Yue
- State Key Laboratory of Heavy Oil Processing
- Center for Bioengineering and Biotechnology
- College of Chemical Engineering
- China University of Petroleum (East China)
- Qingdao
| | - Yan Xu
- State Key Laboratory of Heavy Oil Processing
- Center for Bioengineering and Biotechnology
- College of Chemical Engineering
- China University of Petroleum (East China)
- Qingdao
| | - Shixin Li
- State Key Laboratory of Heavy Oil Processing
- Center for Bioengineering and Biotechnology
- College of Chemical Engineering
- China University of Petroleum (East China)
- Qingdao
| | - Zhen Luo
- State Key Laboratory of Heavy Oil Processing
- Center for Bioengineering and Biotechnology
- College of Chemical Engineering
- China University of Petroleum (East China)
- Qingdao
| | - Xianren Zhang
- State Key Laboratory of Organic–Inorganic Composites
- College of Chemical Engineering
- Beijing University of Chemical Technology
- Beijing
- China
| | - Fang Huang
- State Key Laboratory of Heavy Oil Processing
- Center for Bioengineering and Biotechnology
- College of Chemical Engineering
- China University of Petroleum (East China)
- Qingdao
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28
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Estrada-López ED, Murce E, Franca MPP, Pimentel AS. Prednisolone adsorption on lung surfactant models: insights on the formation of nanoaggregates, monolayer collapse and prednisolone spreading. RSC Adv 2017. [DOI: 10.1039/c6ra28422a] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The adsorption of prednisolone on a lung surfactant model was successfully performed using coarse grained molecular dynamics.
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Affiliation(s)
| | - Erika Murce
- Departamento de Química
- Pontifícia Universidade Católica do Rio de Janeiro
- Rio de Janeiro
- Brazil
| | - Matheus P. P. Franca
- Departamento de Química
- Pontifícia Universidade Católica do Rio de Janeiro
- Rio de Janeiro
- Brazil
| | - Andre S. Pimentel
- Departamento de Química
- Pontifícia Universidade Católica do Rio de Janeiro
- Rio de Janeiro
- Brazil
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29
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All-atom molecular dynamics simulations of lung surfactant protein B: Structural features of SP-B promote lipid reorganization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:3082-3092. [DOI: 10.1016/j.bbamem.2016.09.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 08/30/2016] [Accepted: 09/20/2016] [Indexed: 01/07/2023]
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30
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Baoukina S, Tieleman DP. Computer simulations of lung surfactant. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2431-2440. [PMID: 26922885 DOI: 10.1016/j.bbamem.2016.02.030] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 02/21/2016] [Accepted: 02/23/2016] [Indexed: 01/26/2023]
Abstract
Lung surfactant lines the gas-exchange interface in the lungs and reduces the surface tension, which is necessary for breathing. Lung surfactant consists mainly of lipids with a small amount of proteins and forms a monolayer at the air-water interface connected to bilayer reservoirs. Lung surfactant function involves transfer of material between the monolayer and bilayers during the breathing cycle. Lipids and proteins are organized laterally in the monolayer; selected species are possibly preferentially transferred to bilayers. The complex 3D structure of lung surfactant and the exact roles of lipid organization and proteins remain important goals for research. We review recent simulation studies on the properties of lipid monolayers, monolayers with phase coexistence, monolayer-bilayer transformations, lipid-protein interactions, and effects of nanoparticles on lung surfactant. This article is part of a Special Issue entitled: Biosimulations edited by Ilpo Vattulainen and Tomasz Róg.
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Affiliation(s)
- Svetlana Baoukina
- Department of Biological Sciences and Centre for Molecular Simulation, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada.
| | - D Peter Tieleman
- Department of Biological Sciences and Centre for Molecular Simulation, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada.
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31
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Kodama AT, Kuo CC, Boatwright T, Dennin M. Investigating the effect of particle size on pulmonary surfactant phase behavior. Biophys J 2015; 107:1573-81. [PMID: 25296309 DOI: 10.1016/j.bpj.2014.08.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 07/17/2014] [Accepted: 08/06/2014] [Indexed: 12/14/2022] Open
Abstract
We study the impact of the addition of particles of a range of sizes on the phase transition behavior of lung surfactant under compression. Charged particles ranging from micro- to nanoscale are deposited on lung surfactant films in a Langmuir trough. Surface area versus surface pressure isotherms and fluorescent microscope observations are utilized to determine changes in the phase transition behavior. We find that the deposition of particles close to 20 nm in diameter significantly impacts the coexistence of the liquid-condensed phase and liquid-expanded phase. This includes morphological changes of the liquid-condensed domains and the elimination of the squeeze-out phase in isotherms. Finally, a drastic increase of the domain fraction of the liquid-condensed phase can be observed for the deposition of 20-nm particles. As the particle size is increased, we observe a return to normal phase behavior. The net result is the observation of a critical particle size that may impact the functionality of the lung surfactant during respiration.
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Affiliation(s)
- Akihisa T Kodama
- Department of Physics & Astronomy, University of California, Irvine, California
| | - Chin-Chang Kuo
- Department of Physics & Astronomy, University of California, Irvine, California
| | - Thomas Boatwright
- Department of Physics & Astronomy, University of California, Irvine, California
| | - Michael Dennin
- Department of Physics & Astronomy, University of California, Irvine, California.
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32
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Shaali M, Lara-Avila S, Dommersnes P, Ainla A, Kubatkin S, Jesorka A. Nanopatterning of mobile lipid monolayers on electron-beam-sculpted Teflon AF surfaces. ACS NANO 2015; 9:1271-1279. [PMID: 25541906 DOI: 10.1021/nn5050867] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Direct electron-beam lithography is used to fabricate nanostructured Teflon AF surfaces, which are utilized to pattern surface-supported monolayer phospholipid films with 50 nm lateral feature size. In comparison with unexposed Teflon AF coatings, e-beam-irradiated areas show reduced surface tension and surface potential. For phospholipid monolayer spreading experiments, these areas can be designed to function as barriers that enclose unexposed areas of nanometer dimensions and confine the lipid film within. We show that the effectiveness of the barrier is defined by pattern geometry and radiation dose. This surface preparation technique represents an efficient, yet simple, nanopatterning strategy supporting studies of lipid monolayer behavior in ultraconfined spaces. The generated structures are useful for imaging studies of biomimetic membranes and other specialized surface applications requiring spatially controlled formation of self-assembled, molecularly thin films on optically transparent patterned polymer surfaces with very low autofluorescence.
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Affiliation(s)
- Mehrnaz Shaali
- Department of Chemical and Biological Engineering and ‡Quantum Device Physics Laboratory, Chalmers University of Technology , 41296 Gothenburg, Sweden
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33
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Fuhrmans M, Marelli G, Smirnova YG, Müller M. Mechanics of membrane fusion/pore formation. Chem Phys Lipids 2015; 185:109-28. [DOI: 10.1016/j.chemphyslip.2014.07.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 07/07/2014] [Accepted: 07/24/2014] [Indexed: 11/27/2022]
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Padilla-Chavarría HI, Guizado TRC, Pimentel AS. Molecular dynamics of dibenz[a,h]anthracene and its metabolite interacting with lung surfactant phospholipid bilayers. Phys Chem Chem Phys 2015. [DOI: 10.1039/c5cp01443c] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Dibenz[a,h]anthracene and its metabolite may form aggregates, which have implications in the clearance process of the lung surfactant phospholipid bilayers.
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Affiliation(s)
- Helmut I. Padilla-Chavarría
- Departamento de Química
- Pontifícia Universidade Católica do Rio de Janeiro
- Rua Marques de São Vicente
- Rio de Janeiro
- Brazil
| | - Teobaldo R. C. Guizado
- Departamento de Química
- Pontifícia Universidade Católica do Rio de Janeiro
- Rua Marques de São Vicente
- Rio de Janeiro
- Brazil
| | - Andre S. Pimentel
- Departamento de Química
- Pontifícia Universidade Católica do Rio de Janeiro
- Rua Marques de São Vicente
- Rio de Janeiro
- Brazil
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35
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Deleu M, Crowet JM, Nasir MN, Lins L. Complementary biophysical tools to investigate lipid specificity in the interaction between bioactive molecules and the plasma membrane: A review. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:3171-3190. [DOI: 10.1016/j.bbamem.2014.08.023] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 08/05/2014] [Accepted: 08/21/2014] [Indexed: 02/08/2023]
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36
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Composition, structure and mechanical properties define performance of pulmonary surfactant membranes and films. Chem Phys Lipids 2014; 185:153-75. [PMID: 25260665 DOI: 10.1016/j.chemphyslip.2014.09.002] [Citation(s) in RCA: 183] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/06/2014] [Accepted: 09/11/2014] [Indexed: 12/30/2022]
Abstract
The respiratory surface in the mammalian lung is stabilized by pulmonary surfactant, a membrane-based system composed of multiple lipids and specific proteins, the primary function of which is to minimize the surface tension at the alveolar air-liquid interface, optimizing the mechanics of breathing and avoiding alveolar collapse, especially at the end of expiration. The goal of the present review is to summarize current knowledge regarding the structure, lipid-protein interactions and mechanical features of surfactant membranes and films and how these properties correlate with surfactant biological function inside the lungs. Surfactant mechanical properties can be severely compromised by different agents, which lead to surfactant inhibition and ultimately contributes to the development of pulmonary disorders and pathologies in newborns, children and adults. A detailed comprehension of the unique mechanical and rheological properties of surfactant layers is crucial for the diagnostics and treatment of lung diseases, either by analyzing the contribution of surfactant impairment to the pathophysiology or by improving the formulations in surfactant replacement therapies. Finally, a short review is also included on the most relevant experimental techniques currently employed to evaluate lung surfactant mechanics, rheology, and inhibition and reactivation processes.
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37
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De Moura DC, Bryksa BC, Yada RY. In silico insights into protein-protein interactions and folding dynamics of the saposin-like domain of Solanum tuberosum aspartic protease. PLoS One 2014; 9:e104315. [PMID: 25188221 PMCID: PMC4154668 DOI: 10.1371/journal.pone.0104315] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 06/09/2014] [Indexed: 12/29/2022] Open
Abstract
The plant-specific insert is an approximately 100-residue domain found exclusively within the C-terminal lobe of some plant aspartic proteases. Structurally, this domain is a member of the saposin-like protein family, and is involved in plant pathogen defense as well as vacuolar targeting of the parent protease molecule. Similar to other members of the saposin-like protein family, most notably saposins A and C, the recently resolved crystal structure of potato (Solanum tuberosum) plant-specific insert has been shown to exist in a substrate-bound open conformation in which the plant-specific insert oligomerizes to form homodimers. In addition to the open structure, a closed conformation also exists having the classic saposin fold of the saposin-like protein family as observed in the crystal structure of barley (Hordeum vulgare L.) plant-specific insert. In the present study, the mechanisms of tertiary and quaternary conformation changes of potato plant-specific insert were investigated in silico as a function of pH. Umbrella sampling and determination of the free energy change of dissociation of the plant-specific insert homodimer revealed that increasing the pH of the system to near physiological levels reduced the free energy barrier to dissociation. Furthermore, principal component analysis was used to characterize conformational changes at both acidic and neutral pH. The results indicated that the plant-specific insert may adopt a tertiary structure similar to the characteristic saposin fold and suggest a potential new structural motif among saposin-like proteins. To our knowledge, this acidified PSI structure presents the first example of an alternative saposin-fold motif for any member of the large and diverse SAPLIP family.
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Affiliation(s)
- Dref C. De Moura
- Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
- Department of Food Science, University of Guelph, Guelph, Ontario, Canada
| | - Brian C. Bryksa
- Department of Food Science, University of Guelph, Guelph, Ontario, Canada
| | - Rickey Y. Yada
- Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
- Department of Food Science, University of Guelph, Guelph, Ontario, Canada
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38
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Lopez-Rodriguez E, Pérez-Gil J. Structure-function relationships in pulmonary surfactant membranes: from biophysics to therapy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:1568-85. [PMID: 24525076 DOI: 10.1016/j.bbamem.2014.01.028] [Citation(s) in RCA: 179] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Revised: 01/22/2014] [Accepted: 01/27/2014] [Indexed: 01/01/2023]
Abstract
Pulmonary surfactant is an essential lipid-protein complex to maintain an operative respiratory surface at the mammalian lungs. It reduces surface tension at the alveolar air-liquid interface to stabilise the lungs against physical forces operating along the compression-expansion breathing cycles. At the same time, surfactant integrates elements establishing a primary barrier against the entry of pathogens. Lack or deficiencies of the surfactant system are associated with respiratory pathologies, which treatment often includes supplementation with exogenous materials. The present review summarises current models on the molecular mechanisms of surfactant function, with particular emphasis in its biophysical properties to stabilise the lungs and the molecular alterations connecting impaired surfactant with diseased organs. It also provides a perspective on the current surfactant-based strategies to treat respiratory pathologies. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy.
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Affiliation(s)
- Elena Lopez-Rodriguez
- Departamento de Bioquimica y Biologia Molecular, Facultad de Biologia, Universidad Complutense de Madrid, Madrid, Spain; Institute for Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany; Biomedical Research in End Stage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover, Germany
| | - Jesús Pérez-Gil
- Departamento de Bioquimica y Biologia Molecular, Facultad de Biologia, Universidad Complutense de Madrid, Madrid, Spain
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39
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Hu G, Jiao B, Shi X, Valle RP, Fan Q, Zuo YY. Physicochemical properties of nanoparticles regulate translocation across pulmonary surfactant monolayer and formation of lipoprotein corona. ACS NANO 2013; 7:10525-33. [PMID: 24266809 PMCID: PMC5362675 DOI: 10.1021/nn4054683] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Interaction with the pulmonary surfactant film, being the first line of host defense, represents the initial bio-nano interaction in the lungs. Such interaction determines the fate of the inhaled nanoparticles and their potential therapeutic or toxicological effect. Despite considerable progress in optimizing physicochemical properties of nanoparticles for improved delivery and targeting, the mechanisms by which inhaled nanoparticles interact with the pulmonary surfactant film are still largely unknown. Here, using combined in vitro and in silico methods, we show how hydrophobicity and surface charge of nanoparticles differentially regulate the translocation and interaction with the pulmonary surfactant film. While hydrophilic nanoparticles generally translocate quickly across the pulmonary surfactant film, a significant portion of hydrophobic nanoparticles are trapped by the surfactant film and encapsulated in lipid protrusions upon film compression. Our results support a novel model of pulmonary surfactant lipoprotein corona associated with inhaled nanoparticles of different physicochemical properties. Our data suggest that the study of pulmonary nanotoxicology and nanoparticle-based pulmonary drug delivery should consider this lipoprotein corona.
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Affiliation(s)
- Guoqing Hu
- The State Key Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190, China
- Address correspondence to ;
| | - Bao Jiao
- The State Key Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xinghua Shi
- The State Key Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Russell P. Valle
- Department of Mechanical Engineering, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Qihui Fan
- Department of Mechanical Engineering, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Yi Y. Zuo
- Department of Mechanical Engineering, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
- Address correspondence to ;
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40
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Bennett WD, Tieleman DP. Computer simulations of lipid membrane domains. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:1765-76. [DOI: 10.1016/j.bbamem.2013.03.004] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 02/28/2013] [Accepted: 03/01/2013] [Indexed: 10/27/2022]
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41
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Sachan AK, Galla HJ. Bidirectional surface analysis of monomolecular membrane harboring nanoscale reversible collapse structures. NANO LETTERS 2013; 13:961-966. [PMID: 23391449 DOI: 10.1021/nl303928m] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Determination of orientation of nanoscale collapse structures formed within a Langmuir film at the air-aqueous interface has not been possible by existing experimental techniques. This is however of special importance for pulmonary surfactant films, which form reversible surface-associated reservoirs (SARs) under dynamic lateral compression and expansion. The direction of these SARs with respect to the interface has hitherto remained uncertain. We designed a methodological approach to investigate the directionality of SARs formed in a functional analogue of the pulmonary surfactant lining, where we transferred the compressed film on a holey substrate and performed bidirectional surface imaging of the hole spanning monomolecular membrane harboring SARs. This unambiguously showed association of SARs with the membrane toward the air-side, in contrast to the up to now commonly accepted view of an orientation toward the aqueous phase.
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Affiliation(s)
- Amit K Sachan
- Institute of Biochemistry, Westfälische Wilhelms Universität, Wilhelm-Klemm-Strasse2, 48149 Münster, Germany
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42
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43
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Rausch F, Schicht M, Paulsen F, Ngueya I, Bräuer L, Brandt W. "SP-G", a putative new surfactant protein--tissue localization and 3D structure. PLoS One 2012; 7:e47789. [PMID: 23094088 PMCID: PMC3475697 DOI: 10.1371/journal.pone.0047789] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 09/17/2012] [Indexed: 12/30/2022] Open
Abstract
Surfactant proteins (SP) are well known from human lung. These proteins assist the formation of a monolayer of surface-active phospholipids at the liquid-air interface of the alveolar lining, play a major role in lowering the surface tension of interfaces, and have functions in innate and adaptive immune defense. During recent years it became obvious that SPs are also part of other tissues and fluids such as tear fluid, gingiva, saliva, the nasolacrimal system, and kidney. Recently, a putative new surfactant protein (SFTA2 or SP-G) was identified, which has no sequence or structural identity to the already know surfactant proteins. In this work, computational chemistry and molecular-biological methods were combined to localize and characterize SP-G. With the help of a protein structure model, specific antibodies were obtained which allowed the detection of SP-G not only on mRNA but also on protein level. The localization of this protein in different human tissues, sequence based prediction tools for posttranslational modifications and molecular dynamic simulations reveal that SP-G has physicochemical properties similar to the already known surfactant proteins B and C. This includes also the possibility of interactions with lipid systems and with that, a potential surface-regulatory feature of SP-G. In conclusion, the results indicate SP-G as a new surfactant protein which represents an until now unknown surfactant protein class.
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Affiliation(s)
- Felix Rausch
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Halle, Germany
| | - Martin Schicht
- Institute of Anatomy, Department II, Friedrich Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Friedrich Paulsen
- Institute of Anatomy, Department II, Friedrich Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Ivan Ngueya
- Institute of Anatomy, Department II, Friedrich Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Lars Bräuer
- Institute of Anatomy, Department II, Friedrich Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Wolfgang Brandt
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Halle, Germany
- * E-mail:
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44
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Mendez-Villuendas E, Baoukina S, Tieleman DP. Challenges in analysing and visualizing large-scale molecular dynamics simulations: domain and defect formation in lung surfactant monolayers. ACTA ACUST UNITED AC 2012. [DOI: 10.1088/1742-6596/385/1/012002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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45
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Casals C, Cañadas O. Role of lipid ordered/disordered phase coexistence in pulmonary surfactant function. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:2550-62. [PMID: 22659676 DOI: 10.1016/j.bbamem.2012.05.024] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 05/03/2012] [Accepted: 05/22/2012] [Indexed: 12/27/2022]
Abstract
The respiratory epithelium has evolved to produce a complicated network of extracellular membranes that are essential for breathing and, ultimately, survival. Surfactant membranes form a stable monolayer at the air-liquid interface with bilayer structures attached to it. By reducing the surface tension at the air-liquid interface, surfactant stabilizes the lung against collapse and facilitates inflation. The special composition of surfactant membranes results in the coexistence of two distinct micrometer-sized ordered/disordered phases maintained up to physiological temperatures. Phase coexistence might facilitate monolayer folding to form three-dimensional structures during exhalation and hence allow the film to attain minimal surface tension. These folded structures may act as a membrane reserve and attenuate the increase in membrane tension during inspiration. The present review summarizes what is known of ordered/disordered lipid phase coexistence in lung surfactant, paying attention to the possible role played by domain boundaries in the monolayer-to-multilayer transition, and the correlations of biophysical inactivation of pulmonary surfactant with alterations in phase coexistence.
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Affiliation(s)
- Cristina Casals
- Departamento de Bioquimica y Biologia Molecular, Universidad Complutense de Madrid, Madrid, Spain.
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46
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Risselada HJ, Grubmüller H. How SNARE molecules mediate membrane fusion: recent insights from molecular simulations. Curr Opin Struct Biol 2012; 22:187-96. [PMID: 22365575 DOI: 10.1016/j.sbi.2012.01.007] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 01/11/2012] [Accepted: 01/13/2012] [Indexed: 10/28/2022]
Abstract
SNARE molecules are the core constituents of the protein machinery that facilitate fusion of synaptic vesicles with the presynaptic plasma membrane, resulting in the release of neurotransmitter. On a molecular level, SNARE complexes seem to play a quite versatile and involved role during all stages of fusion. In addition to merely triggering fusion by forcing the opposing membranes into close proximity, SNARE complexes are now seen to also overcome subsequent fusion barriers and to actively guide the fusion reaction up to the expansion of the fusion pore. Here, we review recent advances in the understanding of SNARE-mediated membrane fusion by molecular simulations.
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Affiliation(s)
- Herre Jelger Risselada
- Theoretical Molecular Biophysics Group, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
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47
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Orientation and depth of surfactant protein B C-terminal helix in lung surfactant bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:1165-72. [PMID: 22252270 DOI: 10.1016/j.bbamem.2012.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 12/19/2011] [Accepted: 01/03/2012] [Indexed: 11/22/2022]
Abstract
SP-B(CTERM) is a cationic amphipathic helical peptide and functional fragment composed of residues 63 to 78 of surfactant protein B (SP-B). Static oriented and magic angle spinning solid state NMR, along with molecular dynamics simulation was used to investigate its structure, orientation, and depth in lipid bilayers of several compositions, namely POPC, DPPC, DPPC/POPC/POPG, and bovine lung surfactant extract (BLES). In all lipid environments the peptide was oriented parallel to the membrane surface. While maintaining this approximately planar orientation, SP-B(CTERM) exhibited a flexible topology controlled by subtle variations in lipid composition. SP-B(CTERM)-induced lipid realignment and/or conformational changes at the level of the head group were observed using (31)P solid-state NMR spectroscopy. Measurements of the depth of SP-B(CTERM) indicated the peptide center positions ~8Å more deeply than the phosphate headgroups, a topology that may allow the peptide to promote functional lipid structures without causing micellization upon compression.
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48
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Dhar P, Eck E, Israelachvili JN, Lee DW, Min Y, Ramachandran A, Waring AJ, Zasadzinski JA. Lipid-protein interactions alter line tensions and domain size distributions in lung surfactant monolayers. Biophys J 2012; 102:56-65. [PMID: 22225798 PMCID: PMC3250676 DOI: 10.1016/j.bpj.2011.11.4007] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 11/01/2011] [Accepted: 11/07/2011] [Indexed: 01/15/2023] Open
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.
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Affiliation(s)
- Prajnaparamita Dhar
- Department of Chemical Engineering, University of Kansas, Lawrence, Kansas, USA.
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