1
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Kilicarslan You D, Fuwad A, Lee KH, Kim HK, Kang L, Kim SM, Jeon TJ. Evaluation of the Protective Role of Vitamin E against ROS-Driven Lipid Oxidation in Model Cell Membranes. Antioxidants (Basel) 2024; 13:1135. [PMID: 39334794 PMCID: PMC11428522 DOI: 10.3390/antiox13091135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2024] [Revised: 09/14/2024] [Accepted: 09/18/2024] [Indexed: 09/30/2024] Open
Abstract
Reactive oxygen species (ROS) are chemically reactive oxygen-containing compounds generated by various factors in the body. Antioxidants mitigate the damaging effects of ROS by playing a critical role in regulating redox balance and signaling. In this study, the interplay between reactive oxygen species (ROS) and antioxidants in the context of lipid dynamics were investigated. The interaction between hydrogen peroxide (H2O2) as an ROS and vitamin E (α-tocopherol) as an antioxidant was examined. Model membranes containing both saturated and unsaturated lipids served as experimental platforms to investigate the influence of H2O2 on phospholipid unsaturation and the role of antioxidants in this process. The results demonstrated that H2O2 has a negative effect on membrane stability and disrupts the lipid membrane structure, whereas the presence of antioxidants protects the lipid membrane from the detrimental effects of ROS. The model membranes used here are a useful tool for understanding ROS-antioxidant interactions at the molecular level in vitro.
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Affiliation(s)
- Dilara Kilicarslan You
- Department of Biological Sciences and Bioengineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Ahmed Fuwad
- Department of Mechanical Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
- Department of Biomedical Engineering and Sciences, School of Mechanical and Manufacturing Engineering, National University of Sciences and Technology (NUST), Islamabad 44000, Pakistan
| | - Ki Hyok Lee
- Department of Materials Research Center, Genpeau Corporation, Incheon 21990, Republic of Korea
| | - Hyung Kyo Kim
- Department of Materials Research Center, Genpeau Corporation, Incheon 21990, Republic of Korea
| | - Lifeng Kang
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Pharmacy and Bank Building A15, Sydney, NSW 2006, Australia
| | - Sun Min Kim
- Department of Biological Sciences and Bioengineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
- Department of Mechanical Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
- Biohybrid Systems Research Center (BSRC), Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Tae-Joon Jeon
- Department of Biological Sciences and Bioengineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Pharmacy and Bank Building A15, Sydney, NSW 2006, Australia
- Biohybrid Systems Research Center (BSRC), Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
- Department of Biological Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
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2
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DiPasquale M, Marquardt D. Perceiving the functions of vitamin E through neutron and X-ray scattering. Adv Colloid Interface Sci 2024; 330:103189. [PMID: 38824717 DOI: 10.1016/j.cis.2024.103189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 05/14/2024] [Accepted: 05/17/2024] [Indexed: 06/04/2024]
Abstract
Take your vitamins, or don't? Vitamin E is one of the few lipophilic vitamins in the human diet and is considered an essential nutrient. Over the years it has proven to be a powerful antioxidant and is commercially used as such, but this association is far from linear in physiology. It is increasingly more likely that vitamin E has multiple legitimate biological roles. Here, we review past and current work using neutron and X-ray scattering to elucidate the influence of vitamin E on key features of model membranes that can translate to the biological function(s) of vitamin E. Although progress is being made, the hundred year-old mystery remains unsolved.
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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.
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3
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Egorova KS, Kibardin AV, Posvyatenko AV, Ananikov VP. Mechanisms of Biological Effects of Ionic Liquids: From Single Cells to Multicellular Organisms. Chem Rev 2024; 124:4679-4733. [PMID: 38621413 DOI: 10.1021/acs.chemrev.3c00420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
The review presents a detailed discussion of the evolving field studying interactions between ionic liquids (ILs) and biological systems. Originating from molten salt electrolytes to present multiapplication substances, ILs have found usage across various fields due to their exceptional physicochemical properties, including excellent tunability. However, their interactions with biological systems and potential influence on living organisms remain largely unexplored. This review examines the cytotoxic effects of ILs on cell cultures, biomolecules, and vertebrate and invertebrate organisms. Our understanding of IL toxicity, while growing in recent years, is yet nascent. The established findings include correlations between harmful effects of ILs and their ability to disturb cellular membranes, their potential to trigger oxidative stress in cells, and their ability to cause cell death via apoptosis. Future research directions proposed in the review include studying the distribution of various ILs within cellular compartments and organelles, investigating metabolic transformations of ILs in cells and organisms, detailed analysis of IL effects on proteins involved in oxidative stress and apoptosis, correlation studies between IL doses, exposure times and resulting adverse effects, and examination of effects of subtoxic concentrations of ILs on various biological objects. This review aims to serve as a critical analysis of the current body of knowledge on IL-related toxicity mechanisms. Furthermore, it can guide researchers toward the design of less toxic ILs and the informed use of ILs in drug development and medicine.
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Affiliation(s)
- Ksenia S Egorova
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 119991, Russia
| | - Alexey V Kibardin
- Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology, Ministry of Health of Russian Federation, Moscow 117198, Russia
| | - Alexandra V Posvyatenko
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 119991, Russia
- Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology, Ministry of Health of Russian Federation, Moscow 117198, Russia
| | - Valentine P Ananikov
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 119991, Russia
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4
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DiPasquale M, Nguyen MHL, Castillo SR, Dib IJ, Kelley EG, Marquardt D. Vitamin E Does Not Disturb Polyunsaturated Fatty Acid Lipid Domains. Biochemistry 2022; 61:2366-2376. [PMID: 36227768 DOI: 10.1021/acs.biochem.2c00405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The function of vitamin E in biomembranes remains a prominent topic of discussion. As its limitations as an antioxidant persist and novel functions are discovered, our understanding of the role of vitamin E becomes increasingly enigmatic. As a group of lipophilic molecules (tocopherols and tocotrienols), vitamin E has been shown to influence the properties of its host membrane, and a wealth of research has connected vitamin E to polyunsaturated fatty acid (PUFA) lipids. Here, we use contrast-matched small-angle neutron scattering and differential scanning calorimetry to integrate these fields by examining the influence of vitamin E on lipid domain stability in PUFA-based lipid mixtures. The influence of α-tocopherol, γ-tocopherol, and α-tocopherylquinone on the lateral organization of a 1:1 lipid mixture of saturated distearoylphosphatidylcholine (DSPC) and polyunsaturated palmitoyl-linoleoylphosphatidylcholine (PLiPC) with cholesterol provides a complement to our growing understanding of the influence of tocopherol on lipid phases. Characterization of domain melting suggests a slight depression in the transition temperature and a decrease in transition cooperativity. Tocopherol concentrations that are an order of magnitude higher than anticipated physiological concentrations (2 mol percent) do not significantly perturb lipid domains; however, addition of 10 mol percent is able to destabilize domains and promote lipid mixing. In contrast to this behavior, increasing concentrations of the oxidized product of α-tocopherol (α-tocopherylquinone) induces a proportional increase in domain stabilization. We speculate how the contrasting effect of the oxidized product may supplement the antioxidant response of vitamin E.
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Affiliation(s)
- Mitchell DiPasquale
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, OntarioN9B3P4, Canada
| | - Michael H L Nguyen
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, OntarioN9B3P4, Canada
| | - Stuart R Castillo
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, OntarioN9B3P4, Canada
| | - Isabelle J Dib
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, OntarioN9B3P4, Canada
| | - Elizabeth G Kelley
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland20878, United States
| | - Drew Marquardt
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, OntarioN9B3P4, Canada.,Department of Physics, University of Windsor, Windsor, OntarioN9B3P4, Canada
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5
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Altunayar-Unsalan C, Unsalan O, Mavromoustakos T. Molecular interactions of hesperidin with DMPC/cholesterol bilayers. Chem Biol Interact 2022; 366:110131. [PMID: 36037876 DOI: 10.1016/j.cbi.2022.110131] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 08/05/2022] [Accepted: 08/20/2022] [Indexed: 11/03/2022]
Abstract
Since cell membranes are complex systems, the use of model lipid bilayers is quite important for the study of their interactions with bioactive molecules. Mammalian cell membranes require cholesterol (CHOL) for their structure and function. For this reason, the mixtures of phospholipid and cholesterol are necessary to use in model membrane studies to better simulate the real systems. In the present study, we investigated the effect of the incorporation of hesperidin in model membranes consisting of dimyristoylphosphatidylcholine (DMPC) and CHOL by using differential scanning calorimetry (DSC), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, and atomic force microscopy (AFM). ATR-FTIR results demonstrated that hesperidin increases the fluidity of the DMPC/CHOL binary system. DSC findings indicated that the presence of 5 mol% hesperidin induces a broadening of the main phase transition consisting of three overlapping components. AFM experiments showed that hesperidin increases the thickness of DMPC/CHOL lipid bilayer model membranes. In addition to experimental results, molecular docking studies were conducted with hesperidin and human lanosterol synthase (LS), which is an enzyme found in the final step of cholesterol synthesis, to characterize hesperidin's interactions with its surrounding via its hydroxyl and oxygen groups. Then, hesperidin's ADME/Tox (absorption, distribution, metabolism, excretion and toxicity) profile was computed to see the potential impact on living system. In conclusion, considering the data obtained from experimental studies, this work ensures molecular insights in the interaction between a flavonoid, as an antioxidant drug model, and lipids mimicking those found in mammalian membranes. Moreover, computational studies demonstrated that hesperidin may be a great potential for use as a therapeutic agent for hypercholesterolemia due to its antioxidant property.
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Affiliation(s)
- Cisem Altunayar-Unsalan
- Ege University Central Research Testing and Analysis Laboratory Research and Application Center, 35100, Bornova, Izmir, Turkey.
| | - Ozan Unsalan
- Ege University, Faculty of Science, Department of Physics, 35100, Bornova, Izmir, Turkey.
| | - Thomas Mavromoustakos
- Section of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Athens, 15771, Greece.
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6
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DiPasquale M, Nguyen MHL, Pabst G, Marquardt D. Partial Volumes of Phosphatidylcholines and Vitamin E: α-Tocopherol Prefers Disordered Membranes. J Phys Chem B 2022; 126:6691-6699. [PMID: 36027485 DOI: 10.1021/acs.jpcb.2c04209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Despite its discovery over 95 years ago, the biological and nutritional roles of vitamin E remain subjects of much controversy. Though it is known to possess antioxidant properties, recent assertions have implied that vitamin E may not be limited to this function in living systems. Through densitometry measurements and small-angle X-ray scattering we observe favorable interactions between α-tocopherol and unsaturated phospholipids, with more favorable interactions correlating to an increase in lipid chain unsaturation. Our data provide evidence that vitamin E may preferentially associate with oxygen sensitive lipids─an association that is considered innate for a viable membrane antioxidant.
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Affiliation(s)
- Mitchell DiPasquale
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada
| | - Michael H L Nguyen
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada
| | - Georg Pabst
- Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, University of Graz, Graz 8010, Austria.,BioTechMed-Graz, Graz 8010, Austria
| | - Drew Marquardt
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada.,Department of Physics, University of Windsor, Windsor, Ontario N9B 3P4, Canada
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7
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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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8
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Maiti B, Kumar K, Datta S, Bhattacharya S. Physical-Chemical Characterization of Bilayer Membranes Derived from (±) α-Tocopherol-Based Gemini Lipids and Their Interaction with Phosphatidylcholine Bilayers and Lipoplex Formation with Plasmid DNA. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:36-49. [PMID: 34955028 DOI: 10.1021/acs.langmuir.1c01039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Membrane formation and aggregation properties of two series of (±) α-tocopherol-based cationic gemini lipids without and with hydroxyl functionalities at the headgroup region (TnS n = 3, 4, 5, 6, 8, and 12; THnS n = 4, 5, 6, 8, and 12) with varying polymethylene spacer lengths were investigated extensively while comparing with the corresponding properties of the monomeric counterparts (TM and THM). Liposomal suspensions of each cationic lipid were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), zeta potential measurements, and small-angle X-ray diffraction studies. The length of the spacer and the presence of hydroxyl functionalities at the headgroup region strongly contribute to the aggregation behavior of these gemini lipids in water. The interaction of each tocopherol lipid with a model phospholipid, 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC)-derived vesicles, was thoroughly examined by differential scanning calorimetry (DSC) and 1,6-diphenyl-1,3,5-hexatriene (DPH)-doped fluorescence anisotropy measurements. The binding efficiency of the cationic tocopherol liposomes with plasmid DNA (pDNA) was followed by an ethidium bromide (EB) exclusion assay and zeta potential measurements, whereas negatively charged micellar sodium dodecyl sulfate (SDS)-mediated release of the pDNA from various preformed pDNA-liposomal complexes (lipoplex) was studied by an ethidium bromide (EB) reintercalation assay. The structural transformation of pDNA upon complexation with liposome was characterized using circular dichroism (CD) spectroscopic measurements. Gemini lipid-pDNA interactions depend on both the presence of hydroxyl functionalities at the headgroups and the length of the spacer chain between the headgroups. Succinctly, we performed a detailed physical-chemical characterization of the membranes formed from cationic monomeric and gemini lipids bearing tocopherol as their hydrophobic backbone and describe the role of inserting the -OH group at the headgroup of such lipids.
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Affiliation(s)
- Bappa Maiti
- Department of Organic Chemistry, Indian Institute of Science, Bangalore 560012, India
- Technical Research Centre, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - Krishan Kumar
- Department of Organic Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - Subhasis Datta
- School of Applied & Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - Santanu Bhattacharya
- Department of Organic Chemistry, Indian Institute of Science, Bangalore 560012, India
- Technical Research Centre, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
- School of Applied & Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
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9
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Barouh N, Bourlieu-Lacanal C, Figueroa-Espinoza MC, Durand E, Villeneuve P. Tocopherols as antioxidants in lipid-based systems: The combination of chemical and physicochemical interactions determines their efficiency. Compr Rev Food Sci Food Saf 2021; 21:642-688. [PMID: 34889039 DOI: 10.1111/1541-4337.12867] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 10/22/2021] [Accepted: 10/23/2021] [Indexed: 12/20/2022]
Abstract
Lipid oxidation is a major concern in the food, cosmetic, and pharmaceutical sectors. The degradation of unsaturated lipids affects the nutritional, physicochemical, and organoleptic properties of products and can lead to off-flavors and to the formation of potentially harmful oxidation compounds. To prevent or slow down lipid oxidation, different antioxidant additives are used alone or in combination to achieve the best possible efficiency with the minimum possible quantities. In manufactured products, that is, heterogeneous systems containing lipids as emulsions or bulk phase, the efficiency of an antioxidant is determined not only by its chemical reactivity, but also by its physical properties and its interaction with other compounds present in the products. The antioxidants most widely used on the industrial scale are probably tocopherols, either as natural extracts or pure synthetic molecules. Considerable research has been conducted on their antioxidant activity, but results regarding their efficiency are contradictory. Here, we review the known mechanisms behind the antioxidant activity of tocopherols and discuss the chemical and physical features that determine their efficacy. We first describe their chemical reactivity linked with the main factors that modulate it between efficient antioxidant capacity and potential prooxidant effects. We then describe their chemical interactions with other molecules (phenolic compounds, metals, vitamin C, carotenes, proteins, and phospholipids) that have potential additive, synergistic, or antagonist effects. Finally, we discuss other physical parameters that influence their activity in complex systems including their specific interactions with surfactants in emulsions and their behavior in the presence of association colloids in bulk oils.
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Affiliation(s)
- Nathalie Barouh
- CIRAD, UMR QUALISUD, Montpellier, France.,Qualisud, Univ Montpellier, Avignon Université, CIRAD, Institut Agro, Université de La Réunion, Montpellier, France
| | | | - Maria Cruz Figueroa-Espinoza
- Qualisud, Univ Montpellier, Avignon Université, CIRAD, Institut Agro, Université de La Réunion, Montpellier, France
| | - Erwann Durand
- CIRAD, UMR QUALISUD, Montpellier, France.,Qualisud, Univ Montpellier, Avignon Université, CIRAD, Institut Agro, Université de La Réunion, Montpellier, France
| | - Pierre Villeneuve
- CIRAD, UMR QUALISUD, Montpellier, France.,Qualisud, Univ Montpellier, Avignon Université, CIRAD, Institut Agro, Université de La Réunion, Montpellier, France
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10
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Atkinson J, Marquardt D, DiPasquale M, Harroun T. From fat to bilayers: Understanding where and how vitamin E works. Free Radic Biol Med 2021; 176:73-79. [PMID: 34555454 DOI: 10.1016/j.freeradbiomed.2021.09.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/30/2021] [Accepted: 09/11/2021] [Indexed: 11/16/2022]
Abstract
Vitamin E was one of the last fat-soluble vitamins to be discovered. We provide here an historical review of the discovery and the increasingly more detailed understanding of the role of α-tocopherol both as an antioxidant and as a structural component of phospholipid bilayer membranes. Despite the detailed descriptions now available of the orientation, location, and dynamics of α-tocopherol in lipid bilayers, there are still gaps in our knowledge of the effect of α-tocopherol and its potential receptors than control gene transcription.
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Affiliation(s)
- Jeffrey Atkinson
- Department of Chemistry, Brock University, St. Catharines, ON, L2S3A1, Canada.
| | - Drew Marquardt
- Department of Chemistry and Biochemistry, Windsor, ON, N9B 3P4, Canada; Department of Physics, Windsor, ON, N9B 3P4, Canada
| | | | - Thad Harroun
- Department of Physics, and Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, L2S3A1, Canada
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11
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Song ES, Oh Y, Sung BJ. Interdomain exchange and the flip-flop of cholesterol in ternary component lipid membranes and their effects on heterogeneous cholesterol diffusion. Phys Rev E 2021; 104:044402. [PMID: 34781553 DOI: 10.1103/physreve.104.044402] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 09/17/2021] [Indexed: 11/07/2022]
Abstract
Cell membranes are heterogeneous with a variety of lipids, cholesterol, and proteins and are composed of domains of different compositions. Such heterogeneous environments make the transport of cholesterol complicated: cholesterol not only diffuses within a particular domain but also travels between domains. Cholesterol also flip-flops between upper and lower leaflets such that cholesterol may reside both within leaflets and in the central region between two leaflets. How the presence of multiple domains and the interdomain exchange of cholesterol would affect the cholesterol transport, however, remains elusive. In this study, therefore, we perform molecular dynamics simulations up to 100μs for ternary component lipid membranes, which consist of saturated lipids (dipalmitoylphosphatidylcholine, DPPC), unsaturated lipids (dilinoleylphosphatidylcholine, DIPC), and cholesterol. The ternary component membranes in our simulations form two domains readily: DPPC and DIPC domains. We find that the diffusion of cholesterol molecules is much more heterogeneous and non-Gaussian than expected for binary component lipid membranes of lipids and cholesterol. The non-Gaussian parameter of the cholesterol molecules is about four times larger in the ternary component lipid membranes than in the binary component lipid membranes. Such non-Gaussian and heterogeneous transport of cholesterol arises from the interplay among the interdomain kinetics, the different diffusivity of cholesterol in different domains, and the flip-flop of cholesterol. This suggests that in cell membranes that consist of various domains and proteins, the cholesterol transport can be very heterogeneous. We also find that the mechanism of the interdomain exchange differs for different domains: cholesterol tends to exit the DIPC domain along the central region of the membrane for the DIPC-to-DPPC transition, while the cholesterol is likely to exit the DPPC domain within the membrane leaflet for the DPPC-to-DIPC transition. Also, the interdomain exchange kinetics of cholesterol for the DPPC-to-DIPC transition is up to 7.9 times slower than the DIPC-to-DPPC transition.
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Affiliation(s)
- Eun Sub Song
- Department of Chemistry, Sogang University, Seoul 04107, Republic of Korea
| | - Younghoon Oh
- Department of Chemistry, Sogang University, Seoul 04107, Republic of Korea
| | - Bong June Sung
- Department of Chemistry, Sogang University, Seoul 04107, Republic of Korea
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12
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Molecular dynamics simulation study of the positioning and dynamics of α-tocopherol in phospholipid bilayers. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2021; 50:889-903. [PMID: 34052860 DOI: 10.1007/s00249-021-01548-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 10/25/2020] [Accepted: 05/17/2021] [Indexed: 01/18/2023]
Abstract
Using molecular dynamics simulations, we investigate the interaction of α-tocopherol (α-toc) with dipalmitoylphosphatidylcholine (DPPC), dimyristoylphosphatidylcholine (DMPC), palmitoyloleoylphosphatidylcholine (POPC), and palmitoyloleoylphosphatidylethanolamine (POPE) lipid bilayers. The goal is to develop a better understanding of the positioning and orientation of α-toc inside the bilayers; properties of significant relevance to α-toc anti-oxidant activity. We investigated bilayer systems with 128 lipids in the presence of either single or 14 α-toc molecules. The single α-toc bilayer systems were investigated via biased MD simulations in which the potential of mean force (PMF) and diffusivity were obtained as functions of the distance between α-toc head group and bilayer center. The higher α-toc concentration systems were investigated with unbiased MD simulations. For all four bilayers at both concentrations, the simulations show that the most probable location of the α-toc hydroxyl group is just below the lipid carbonyl group. Overall, the simulation results are in good agreement with existing experimental data except for the DMPC bilayer system for which some experiments predict α-toc to be located closer to bilayer center. The flip-flop frequency calculated shows that the α-toc flip-flop rate is sensitive to bilayer lipid type. In particular, α-toc has a much lower flip-flop rate in a POPE bilayer compared to the three PC lipid bilayers due to the smaller area per lipid in the POPE bilayer. For DMPC and POPC, the α-toc flip-flop rates are significantly higher at higher α-toc concentration and this appears to be related to the local structural disruption caused by α-toc clusters spanning the bilayer.
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13
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DiPasquale M, Gbadamosi O, Nguyen MHL, Castillo SR, Rickeard BW, Kelley EG, Nagao M, Marquardt D. A Mechanical Mechanism for Vitamin E Acetate in E-cigarette/Vaping-Associated Lung Injury. Chem Res Toxicol 2020; 33:2432-2440. [PMID: 32842741 DOI: 10.1021/acs.chemrestox.0c00212] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The outbreak of electronic-cigarette/vaping-associated lung injury (EVALI) has made thousands ill. This lung injury has been attributed to a physical interaction between toxicants from the vaping solution and the pulmonary surfactant. In particular, studies have implicated vitamin E acetate as a potential instigator of EVALI. Pulmonary surfactant is vital to proper respiration through the mechanical processes of adsorption and interface stability to achieve and maintain low surface tension at the air-liquid interface. Using neutron spin echo spectroscopy, we investigate the impact of vitamin E acetate on the mechanical properties of two lipid-only pulmonary surfactant mimics: pure 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and a more comprehensive lipid mixture. It was found that increasing vitamin E acetate concentration nonlinearly increased membrane fluidity and area compressibility to a plateau. Softer membranes would promote adsorption to the air-liquid interface during inspiration as well as collapse from the interface during expiration. These findings indicate the potential for the failure of the pulmonary surfactant upon expiration, attributed to monolayer collapse. This collapse could contribute to the observed EVALI signs and symptoms, including shortness of breath and pneumonitis.
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Affiliation(s)
| | | | | | | | | | - Elizabeth G Kelley
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Michihiro Nagao
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States.,Center for Exploration of Energy and Matter, Department of Physics, Indiana University, Bloomington, Indiana 47408, United States.,Department of Physics and AstronomyUniversity of DelawareNewarkDelaware19716United States
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14
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DiPasquale M, Nguyen MHL, Rickeard BW, Cesca N, Tannous C, Castillo SR, Katsaras J, Kelley EG, Heberle FA, Marquardt D. The antioxidant vitamin E as a membrane raft modulator: Tocopherols do not abolish lipid domains. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2020; 1862:183189. [PMID: 31954106 PMCID: PMC10443432 DOI: 10.1016/j.bbamem.2020.183189] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 01/07/2020] [Accepted: 01/09/2020] [Indexed: 01/06/2023]
Abstract
The antioxidant vitamin E is a commonly used vitamin supplement. Although the multi-billion dollar vitamin and nutritional supplement industry encourages the use of vitamin E, there is very little evidence supporting its actual health benefits. Moreover, vitamin E is now marketed as a lipid raft destabilizing anti-cancer agent, in addition to its antioxidant behaviour. Here, we studied the influence of vitamin E and some of its vitamers on membrane raft stability using phase separating unilamellar lipid vesicles in conjunction with small-angle scattering techniques and fluorescence microscopy. We find that lipid phase behaviour remains unperturbed well beyond physiological concentrations of vitamin E (up to a mole fraction of 0.10). Our results are consistent with a proposed line active role of vitamin E at the domain boundary. We discuss the implications of these findings as they pertain to lipid raft modification in native membranes, and propose a new hypothesis for the antioxidant mechanism of vitamin E.
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Affiliation(s)
- Mitchell DiPasquale
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario,Canada
| | - Michael H L Nguyen
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario,Canada
| | - Brett W Rickeard
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario,Canada
| | - Nicole Cesca
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario,Canada
| | - Christopher Tannous
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario,Canada
| | - Stuart R Castillo
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario,Canada
| | - John Katsaras
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; Joint Institute for Neutron Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, USA
| | - Elizabeth G Kelley
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | | | - Drew Marquardt
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario,Canada; Department of Physics, University of Windsor, Windsor, Ontario, Canada.
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15
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Subramaniam R, Lynch S, Cen Y, Balaz S. Polarity of Hydrated Phosphatidylcholine Headgroups. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:8460-8471. [PMID: 31244216 PMCID: PMC6853183 DOI: 10.1021/acs.langmuir.8b03992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The headgroup (H) stratum (sometimes called the polar region) of membrane bilayers is a relevant yet poorly understood solvation phase for small molecules and macromolecules interacting with the membranes. Solvation of compounds in bilayer strata is characterized experimentally by wide- and small-angle X-ray scattering, neutron diffraction, and various NMR techniques. The quantification is tedious and only available for a limited set of small molecules. Our recently published model of liposome partitioning of small molecules shows that solvation of compounds in the H-stratum of fluid phosphatidylcholine (PC) bilayers correlates well with their solvation in hydrated diacetyl phosphatidylcholine (DAcPC), and solvation in the core (C) depends in a similar way on that in n-hexadecane. These two correlations became a basis for a model describing the location of compounds in the H- and C-strata and at the connecting interface as a nonlinear function of the fragment solvation characteristics of the compounds. In this study, refractivity of hydrated DAcPC phases with varying water contents was measured and polarity was determined using the steady-state fluorescence of indole and Nile Red. The results were compared with the published data obtained by other techniques for PC bilayers in liposomes or on solid supports. The demonstrated qualitative agreement, as well as the polarity and refractivity dependencies on the DAcPC concentration, supports the suitability of hydrated DAcPC as the H-stratum surrogate. Interestingly, depending on hydrations typical for the H-strata of fluid PC bilayers, the dielectric constant could decrease significantly from 31.0 to 7.3 for 16 and 8 water molecules per headgroup, respectively. Although additional experiments are needed for confirmation, this observation could help set proper dielectric constant magnitudes in continuum-based computational models of accumulation and crossing of the PC bilayers with varying hydration levels thanks to the temperature or the structure of fatty acid chains.
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Affiliation(s)
| | | | | | - Stefan Balaz
- Corresponding author: Stefan Balaz, Albany College of Pharmacy and Health Sciences, Vermont Campus, Department of Pharmaceutical Sciences, 261 Mountain View Road, Colchester, VT 05446, United States, phone 802-735-2615,
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16
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Vitamin E-inspired multi-scale imaging agent. Bioorg Med Chem Lett 2019; 29:107-114. [PMID: 30459096 DOI: 10.1016/j.bmcl.2018.10.052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 09/13/2018] [Accepted: 10/31/2018] [Indexed: 12/18/2022]
Abstract
The production and use of multi-modal imaging agents is on the rise. The vast majority of these imaging agents are limited to a single length scale for the agent (e.g. tissues only), which is typically at the organ or tissue scale. This work explores the synthesis of such an imaging agent and discusses the applications of our vitamin E-inspired multi-modal and multi-length scale imaging agents TB-Toc ((S,E)-5,5-difluoro-7-(2-(5-((6-hydroxy-2,5,7,8-tetramethylchroman-2-yl) methyl) thiophen-2-yl) vinyl)-9-methyl-5H-dipyrrolo-[1,2-c:2',1'-f][1,3,2]diazaborinin-4-ium-5-uide). We investigate the toxicity of TB-Toc along with the starting materials and lipid based delivery vehicle in mouse myoblasts and fibroblasts. Further we investigate the uptake of TB-Toc delivered to cultured cells in both solvent and liposomes. TB-Toc has low toxicity, and no change in cell viability was observed up to concentrations of 10 mM. TB-Toc shows time-dependent cellular uptake that is complete in about 30 min. This work is the first step in demonstrating our vitamin E derivatives are viable multi-modal and length scale diagnostic tools.
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17
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Oh Y, Sung BJ. Facilitated and Non-Gaussian Diffusion of Cholesterol in Liquid Ordered Phase Bilayers Depends on the Flip-Flop and Spatial Arrangement of Cholesterol. J Phys Chem Lett 2018; 9:6529-6535. [PMID: 30346769 DOI: 10.1021/acs.jpclett.8b02982] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The diffusion of cholesterol in biological membranes is critical to cellular processes such as the formation of cholesterol-enriched domains. The cholesterol diffusion may be complicated especially when cholesterol flip-flops and/or stays at the membrane center. Understanding the diffusion mechanism of cholesterol at a molecular level should be, therefore, a topic of interest. We perform molecular dynamics simulations up to 100 μs for lipid bilayers with various concentrations of cholesterol. We find that cholesterol diffusion in the liquid ordered phase depends on whether it is within leaflets or at the bilayer center, is non-Gaussian for several microseconds, and is enhanced significantly compared to that of lipids. Cholesterol at the bilayer center diffuses fast, while cholesterol in the hydrocarbon region with upright orientation diffuses relatively slowly. Such position-dependent dynamics of cholesterol leads to facilitated and non-Gaussian diffusion.
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Affiliation(s)
- Younghoon Oh
- Department of Chemistry and Research Institute for Basic Science , Sogang University , Seoul 04107 , Republic of Korea
| | - Bong June Sung
- Department of Chemistry and Research Institute for Basic Science , Sogang University , Seoul 04107 , Republic of Korea
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18
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Boonnoy P, Karttunen M, Wong-ekkabut J. Does α-Tocopherol Flip-Flop Help to Protect Membranes Against Oxidation? J Phys Chem B 2018; 122:10362-10370. [DOI: 10.1021/acs.jpcb.8b09064] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | | | - Jirasak Wong-ekkabut
- Thailand Center of Excellence in Physics, Commission on Higher Education, Bangkok 10400, Thailand
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19
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Shahzadi Z, Das S, Bala T, Mukhopadhyay C. Phase Behavior of GM1-Containing DMPC-Cholesterol Monolayer: Experimental and Theoretical Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:11602-11611. [PMID: 30173524 DOI: 10.1021/acs.langmuir.8b02621] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Organization and distribution of lipids in cellular membranes play an important role in a diverse range of biological processes, such as membrane trafficking and signaling. Here, we present the combined experimental and simulated results to elucidate the phase behavioral features of ganglioside monosialo 1 (GM1)-containing mixed monolayer of the lipids 1,2-dimyristoyl- sn-glycero-3-phosphocholine (DMPC) and cholesterol (CHOL). Two monolayers having compositions DMPC-CHOL and GM1-DMPC-CHOL are investigated at air-water and air-solid interfaces using Langmuir-Blodgett experiments and scanning electron microscopy (SEM), respectively, to ascertain the phase behavior change of the monolayers. Surface pressure isotherms and SEM imaging of domain formation indicate that addition of GM1 to the monolayer at low surface pressure causes a fluidization of the system but once the system attains the surface pressure corresponding to its liquid-condensed phase, the monolayer becomes more ordered than the system devoid of GM1 and interacts among each other more cooperatively. Besides, the condensing effect of cholesterol on the DMPC monolayer was also verified by our experiments. Apart from these, the effects induced by GM1 on the phase behavior of the binary mixture of DMPC-CHOL were studied with and without applying liquid-expanded (LE)-liquid-condensed (LC) equilibrium surface pressure using molecular dynamics (MD) simulation. Our molecular dynamics (MD) simulation results give an atomistic-level explanation of our experimental findings and furnish a similar conclusion.
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Affiliation(s)
- Zarrin Shahzadi
- Department of Chemistry , University of Calcutta , 92, A.P.C. Road , Kolkata 700009 , India
| | - Subhasis Das
- Department of Chemistry , University of Calcutta , 92, A.P.C. Road , Kolkata 700009 , India
| | - Tanushree Bala
- Department of Chemistry , University of Calcutta , 92, A.P.C. Road , Kolkata 700009 , India
| | - Chaitali Mukhopadhyay
- Department of Chemistry , University of Calcutta , 92, A.P.C. Road , Kolkata 700009 , India
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20
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Ausili A, Torrecillas A, de Godos AM, Corbalán-García S, Gómez-Fernández JC. Phenolic Group of α-Tocopherol Anchors at the Lipid-Water Interface of Fully Saturated Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:3336-3348. [PMID: 29447442 DOI: 10.1021/acs.langmuir.7b04142] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
α-Tocopherol is considered to carry on a very important role as an antioxidant for membranes and lipoproteins and other biological roles as membrane stabilizers and bioactive lipids. Given its essential role, it is very important to fully understand its location in the membrane. In this work, the vertical location of vitamin E in saturated membranes has been studied using biophysical techniques. Small- and wide-angle X-ray diffraction experiments show that α-tocopherol alters the water layer between bilayers in both 1,2-dimyristoyl- sn-glycero-3-phosphocholine (DMPC) and 1,2-dipalmitoyl- sn-glycero-3-phosphocholine (DPPC), indicating its proximity to this surface. The quenching of the intrinsic fluorescence of α-tocopherol indicates a low quenching efficiency by acrylamide and a higher quenching by 5-doxyl-PC than by 9- and 16-doxyl-PC. These results suggest that in both DMPC and DPPC membranes, the chromanol ring is not far away from the surface of the membrane but within the bilayer. 1H nuclear Overhauser enhancement spectroscopy magic-angle spinning-nuclear magnetic resonance studies showed that α-tocopherol is localized in a similar manner in DMPC and DPPC membranes, with the chromanol ring embedded in the upper part of the hydrophobic bilayer. Using attenuated total reflection-Fourier transform infrared spectroscopy, it was observed that the tail chain of α-tocopherol lies nearly parallel to the acyl chains of DMPC and DPPC. Taking these results together, it was concluded that in both DMPC and DPPC, the hydroxyl group of the chromanol ring will establish hydrogen bonding with water on the membrane surface, and the main axis of the α-tocopherol molecule will be perpendicular to the bilayer plane.
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Affiliation(s)
- Alessio Ausili
- Departamento de Bioquímica y Biología Molecular "A", Facultad de Veterinaria, Regional Campus of International Excellence Mare Nostrum , Universidad de Murcia , Apartado de Correos 4021 , E-30080 Murcia , Spain
| | - Alejandro Torrecillas
- Departamento de Bioquímica y Biología Molecular "A", Facultad de Veterinaria, Regional Campus of International Excellence Mare Nostrum , Universidad de Murcia , Apartado de Correos 4021 , E-30080 Murcia , Spain
| | - Ana M de Godos
- Departamento de Bioquímica y Biología Molecular "A", Facultad de Veterinaria, Regional Campus of International Excellence Mare Nostrum , Universidad de Murcia , Apartado de Correos 4021 , E-30080 Murcia , Spain
| | - Senena Corbalán-García
- Departamento de Bioquímica y Biología Molecular "A", Facultad de Veterinaria, Regional Campus of International Excellence Mare Nostrum , Universidad de Murcia , Apartado de Correos 4021 , E-30080 Murcia , Spain
| | - Juan C Gómez-Fernández
- Departamento de Bioquímica y Biología Molecular "A", Facultad de Veterinaria, Regional Campus of International Excellence Mare Nostrum , Universidad de Murcia , Apartado de Correos 4021 , E-30080 Murcia , Spain
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21
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Ausili A, de Godos AM, Torrecillas A, Aranda FJ, Corbalán-García S, Gómez-Fernández JC. The vertical location of α-tocopherol in phosphatidylcholine membranes is not altered as a function of the degree of unsaturation of the fatty acyl chains. Phys Chem Chem Phys 2018; 19:6731-6742. [PMID: 28211935 DOI: 10.1039/c6cp08872d] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
α-Tocopherol is a natural preservative that prevents free radical chain oxidations in biomembranes. We have studied the location of α-tocopherol in model membranes formed by different unsaturated phosphatidylcholines, namely 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphocholine (PLPC), 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine (PAPC) and 1-palmitoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine (PDPC). Small angle X-ray diffraction revealed that α-tocopherol was well mixed with all the phospholipids. In all the cases only one lamellar phase was detected. Very modest changes occasioned by α-tocopherol were observed in the electron density profiles. The results obtained from quenching of α-tocopherol intrinsic fluorescence by acrylamide showed that this vitamin was inefficiently quenched in the four types of membranes, indicating that the fluorescent chromanol ring was poorly accessible for this hydrophilic quencher. Compatible with that, quenching by doxyl derivatives of phosphatidylcholines indicated that the chromanol ring was close in the four membranes to the nitroxide probe located at position 5. Quenching by doxyl-phosphatidylcholines also indicated that the efficiency of quenching was higher in POPC than in the other unsaturated phospholipids. 1H-MAS-NMR showed that α-tocopherol induced chemical shifts of protons from the phospholipids, especially of those bonded to carbons 2 and 3 of the acyl chains of the four phospholipids studied. The 1H-MAS-NMR NOESY results suggested that the lower part of the chromanol ring was located between the C3 of the fatty acyl chains and the centre of the hydrophobic monolayer for the four phospholipid membranes studied. Taken together, these results suggest that α-tocopherol is located, in all the membranes studied, with the chromanol ring within the hydrophobic palisade but not far away from the lipid-water interface.
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Affiliation(s)
- Alessio Ausili
- Departamento de Bioquímica y Biología Molecular "A", Facultad de Veterinaria, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Apartado de Correos 4021, E-30080-Murcia, Spain.
| | - Ana M de Godos
- Departamento de Bioquímica y Biología Molecular "A", Facultad de Veterinaria, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Apartado de Correos 4021, E-30080-Murcia, Spain.
| | - Alejandro Torrecillas
- Departamento de Bioquímica y Biología Molecular "A", Facultad de Veterinaria, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Apartado de Correos 4021, E-30080-Murcia, Spain.
| | - Francisco J Aranda
- Departamento de Bioquímica y Biología Molecular "A", Facultad de Veterinaria, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Apartado de Correos 4021, E-30080-Murcia, Spain.
| | - Senena Corbalán-García
- Departamento de Bioquímica y Biología Molecular "A", Facultad de Veterinaria, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Apartado de Correos 4021, E-30080-Murcia, Spain.
| | - Juan C Gómez-Fernández
- Departamento de Bioquímica y Biología Molecular "A", Facultad de Veterinaria, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Apartado de Correos 4021, E-30080-Murcia, Spain.
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22
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Marquardt D, Frontzek MD, Zhao Y, Chakoumakos BC, Katsaras J. Neutron diffraction from aligned stacks of lipid bilayers using the WAND instrument. J Appl Crystallogr 2018. [DOI: 10.1107/s1600576718001243] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Neutron diffraction from aligned stacks of lipid bilayers is examined using the Wide-Angle Neutron Diffractometer (WAND), located at the High Flux Isotope Reactor, Oak Ridge, Tennessee, USA. Data were collected at different levels of hydration and neutron contrast by varying the relative humidity (RH) and H2O/D2O ratio from multi-bilayers of dioleoylphosphatidylcholine and sunflower phosphatidylcholine extract aligned on single-crystal silicon substrates. This work highlights the capabilites of a newly fabricated sample hydration cell, which allows the lipid bilayers to be hydrated with varying H/D ratios from the RH generated by saturated salt solutions, and also demonstrates WAND's capability as an instrument suitable for the study of aligned lipid multi-bilayers.
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23
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Nandi S, Malishev R, Bhunia SK, Kolusheva S, Jopp J, Jelinek R. Lipid-Bilayer Dynamics Probed by a Carbon Dot-Phospholipid Conjugate. Biophys J 2017; 110:2016-25. [PMID: 27166809 DOI: 10.1016/j.bpj.2016.04.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 03/09/2016] [Accepted: 04/04/2016] [Indexed: 12/28/2022] Open
Abstract
Elucidating the dynamic properties of membranes is important for understanding fundamental cellular processes and for shedding light on the interactions of proteins, drugs, and viruses with the cell surface. Dynamic studies of lipid bilayers have been constrained, however, by the relatively small number of pertinent molecular probes and the limited physicochemical properties of the probes. We show that a lipid conjugate comprised of a fluorescent carbon dot (C-dot) covalently attached to a phospholipid constitutes a versatile and effective vehicle for studying bilayer dynamics. The C-dot-modified phospholipids readily incorporated within biomimetic membranes, including solid-supported bilayers and small and giant vesicles, and inserted into actual cellular membranes. We employed the C-dot-phospholipid probe to elucidate the effects of polymyxin-B (a cytolytic peptide), valproic acid (a lipophilic drug), and amyloid-β (a peptide associated with Alzheimer's disease) upon bilayer fluidity and lipid dynamics through the application of various biophysical techniques.
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Affiliation(s)
- Sukhendu Nandi
- Department of Chemistry, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Ravit Malishev
- Department of Chemistry, Ben Gurion University of the Negev, Beer Sheva, Israel
| | | | - Sofiya Kolusheva
- Ilse Katz Institute for Nanoscale Science & Technology, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Jürgen Jopp
- Ilse Katz Institute for Nanoscale Science & Technology, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Raz Jelinek
- Department of Chemistry, Ben Gurion University of the Negev, Beer Sheva, Israel; Ilse Katz Institute for Nanoscale Science & Technology, Ben Gurion University of the Negev, Beer Sheva, Israel.
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24
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Sharma VK, Mamontov E, Ohl M, Tyagi M. Incorporation of aspirin modulates the dynamical and phase behavior of the phospholipid membrane. Phys Chem Chem Phys 2017; 19:2514-2524. [DOI: 10.1039/c6cp06202d] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Effect of aspirin on the microscopic dynamics of a membrane has been investigated using quasielastic neutron scattering and neutron spin echo techniques.
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Affiliation(s)
- V. K. Sharma
- Solid State Physics Division
- Bhabha Atomic Research Centre
- Mumbai 400085
- India
| | - E. Mamontov
- Chemical and Engineering Materials Division
- Neutron Sciences Directorate
- Oak Ridge National Laboratory
- Oak Ridge
- USA
| | - M. Ohl
- Jülich Center for Neutron Science
- Oak Ridge
- USA
| | - M. Tyagi
- National Institute of Standards and Technology Center for Neutron Research
- Gaithersburg
- USA
- Department of Materials Science and Engineering
- University of Maryland
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25
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Marquardt D, Van Oosten BJ, Ghelfi M, Atkinson J, Harroun TA. Vitamin E Circular Dichroism Studies: Insights into Conformational Changes Induced by the Solvent's Polarity. MEMBRANES 2016; 6:membranes6040056. [PMID: 27983631 PMCID: PMC5192412 DOI: 10.3390/membranes6040056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/07/2016] [Accepted: 12/08/2016] [Indexed: 11/16/2022]
Abstract
We used circular dichroism (CD) to study differences in CD spectra between α-, δ-, and methylated-α-tocopherol in solvents with different polarities. CD spectra of the different tocopherol structures differ from each other in intensity and peak locations, which can be attributed to chromanol substitution and the ability to form hydrogen bonds. In addition, each structure was examined in different polarity solvents using the Reichardt index-a measure of the solvent's ionizing ability, and a direct measurement of solvent-solute interactions. Differences across solvents indicate that hydrogen bonding is a key contributor to CD spectra at 200 nm. These results are a first step in examining the hydrogen bonding abilities of vitamin E in a lipid bilayer.
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Affiliation(s)
- Drew Marquardt
- Department of Physics, Brock University, St. Catharines, ON L2S 3A1, Canada.
- Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, University of Graz, Graz 8010, Austria.
- BioTechMed-Graz, Graz 8010, Austria.
| | - Brad J Van Oosten
- Department of Physics, Brock University, St. Catharines, ON L2S 3A1, Canada.
| | - Mikel Ghelfi
- Department of Chemistry, Brock University, St. Catharines, ON L2S 3A1, Canada.
| | - Jeffrey Atkinson
- Department of Chemistry, Brock University, St. Catharines, ON L2S 3A1, Canada.
| | - Thad A Harroun
- Department of Physics, Brock University, St. Catharines, ON L2S 3A1, Canada.
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26
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Marquardt D, Kučerka N, Wassall SR, Harroun TA, Katsaras J. Cholesterol's location in lipid bilayers. Chem Phys Lipids 2016; 199:17-25. [DOI: 10.1016/j.chemphyslip.2016.04.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 04/01/2016] [Accepted: 04/02/2016] [Indexed: 02/07/2023]
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27
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Di Meo F, Fabre G, Berka K, Ossman T, Chantemargue B, Paloncýová M, Marquet P, Otyepka M, Trouillas P. In silico pharmacology: Drug membrane partitioning and crossing. Pharmacol Res 2016; 111:471-486. [PMID: 27378566 DOI: 10.1016/j.phrs.2016.06.030] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 06/30/2016] [Accepted: 06/30/2016] [Indexed: 01/09/2023]
Abstract
Over the past decade, molecular dynamics (MD) simulations have become particularly powerful to rationalize drug insertion and partitioning in lipid bilayers. MD simulations efficiently support experimental evidences, with a comprehensive understanding of molecular interactions driving insertion and crossing. Prediction of drug partitioning is discussed with respect to drug families (anesthetics; β-blockers; non-steroidal anti-inflammatory drugs; antioxidants; antiviral drugs; antimicrobial peptides). To accurately evaluate passive permeation coefficients turned out to be a complex theoretical challenge; however the recent methodological developments based on biased MD simulations are particularly promising. Particular attention is paid to membrane composition (e.g., presence of cholesterol), which influences drug partitioning and permeation. Recent studies concerning in silico models of membrane proteins involved in drug transport (influx and efflux) are also reported here. These studies have allowed gaining insight in drug efflux by, e.g., ABC transporters at an atomic resolution, explicitly accounting for the mandatory forces induced by the surrounded lipid bilayer. Large-scale conformational changes were thoroughly analyzed.
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Affiliation(s)
- Florent Di Meo
- INSERM UMR 850, Univ. Limoges, Faculty of Pharmacy, 2 rue du Dr Marcland, F-87025, Limoges, France
| | - Gabin Fabre
- LCSN, Univ. Limoges, Faculty of Pharmacy, 2 rue du Dr Marcland, F-87025, Limoges, France
| | - Karel Berka
- Regional Centre for Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky̿ University, Olomouc, Czech Republic
| | - Tahani Ossman
- INSERM UMR 850, Univ. Limoges, Faculty of Pharmacy, 2 rue du Dr Marcland, F-87025, Limoges, France
| | - Benjamin Chantemargue
- INSERM UMR 850, Univ. Limoges, Faculty of Pharmacy, 2 rue du Dr Marcland, F-87025, Limoges, France; Regional Centre for Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky̿ University, Olomouc, Czech Republic
| | - Markéta Paloncýová
- Regional Centre for Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky̿ University, Olomouc, Czech Republic
| | - Pierre Marquet
- INSERM UMR 850, Univ. Limoges, Faculty of Pharmacy, 2 rue du Dr Marcland, F-87025, Limoges, France
| | - Michal Otyepka
- Regional Centre for Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky̿ University, Olomouc, Czech Republic
| | - Patrick Trouillas
- INSERM UMR 850, Univ. Limoges, Faculty of Pharmacy, 2 rue du Dr Marcland, F-87025, Limoges, France; Regional Centre for Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky̿ University, Olomouc, Czech Republic.
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28
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Sharma VK, Mamontov E, Tyagi M, Urban VS. Effect of α-Tocopherol on the Microscopic Dynamics of Dimyristoylphosphatidylcholine Membrane. J Phys Chem B 2015; 120:154-63. [DOI: 10.1021/acs.jpcb.5b10417] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- V. K. Sharma
- Biology
and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Solid
State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - E. Mamontov
- Chemical
and Engineering Materials Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - M. Tyagi
- National Institute of Standards and Technology Center for Neutron Research, Gaithersburg, Maryland 20899, United States
- Department
of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - V. S. Urban
- Biology
and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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29
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Gaul V, Lopez SG, Lentz BR, Moran N, Forster RJ, Keyes TE. The lateral diffusion and fibrinogen induced clustering of platelet integrin αIIbβ3 reconstituted into physiologically mimetic GUVs. Integr Biol (Camb) 2015; 7:402-11. [PMID: 25720532 DOI: 10.1039/c5ib00003c] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Platelet integrin αIIbβ3 is a key mediator of platelet activation and thrombosis. Upon activation αIIbβ3 undergoes significant conformational rearrangement, inducing complex bidirectional signalling and protein recruitment leading to platelet activation. Reconstituted lipid models of the integrin can enhance our understanding of the structural and mechanistic details of αIIbβ3 behaviour away from the complexity of the platelet machinery. Here, a novel method of αIIbβ3 insertion into Giant Unilamellar Vesicles (GUVs) is described that allows for effective integrin reconstitution unrestricted by lipid composition. αIIbβ3 was inserted into two GUV lipid compositions that seek to better mimic the platelet membrane. First, "nature's own", comprising 32% DOPC, 25% DOPE, 20% CH, 15% SM and 8% DOPS, intended to mimic the platelet cell membrane. Fluorescence Lifetime Correlation Spectroscopy (FLCS) reveals that exposure of the integrin to the activators Mn(2+) or DTT does not influence the diffusion coefficient of αIIbβ3. Similarly, exposure to αIIbβ3's primary ligand fibrinogen (Fg) alone does not affect αIIbβ3's diffusion coefficient. However, addition of Fg with either activator reduces the integrin diffusion coefficient from 2.52 ± 0.29 to μm(2) s(-1) to 1.56 ± 0.26 (Mn(2+)) or 1.49 ± 0.41 μm(2) s(-1) (DTT) which is consistent with aggregation of activated αIIbβ3 induced by fibrinogen binding. The Multichannel Scaler (MCS) trace shows that the integrin-Fg complex diffuses through the confocal volume in clusters. Using the Saffman-Delbrück model as a first approximation, the diffusion coefficient of the complex suggests at least a 20-fold increase in the radius of membrane bound protein, consistent with integrin clustering. Second, αIIbβ3 was also reconstituted into a "raft forming" GUV with well defined liquid disordered (Ld) and liquid ordered (Lo) phases. Using confocal microscopy and lipid partitioning dyes, αIIbβ3 showed an affinity for the DOPC rich Ld phase of the raft forming GUVs, and was effectively excluded from the cholesterol and sphingomyelin rich Lo phase. Activation and Fg binding of the integrin did not alter the distribution of αIIbβ3 between the lipid phases. This observation suggests partitioning of the activated fibrinogen bound αIIbβ3 into cholesterol rich domains is not responsible for the integrin clustering observed.
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Affiliation(s)
- Vinnie Gaul
- School of Chemical Sciences and National Biophotonics and Imaging Platform, Dublin City University, Dublin 9, Ireland.
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30
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Leng X, Kinnun JJ, Marquardt D, Ghefli M, Kučerka N, Katsaras J, Atkinson J, Harroun TA, Feller SE, Wassall SR. α-Tocopherol Is Well Designed to Protect Polyunsaturated Phospholipids: MD Simulations. Biophys J 2015; 109:1608-18. [PMID: 26488652 PMCID: PMC4624157 DOI: 10.1016/j.bpj.2015.08.032] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 08/20/2015] [Accepted: 08/24/2015] [Indexed: 01/08/2023] Open
Abstract
The presumptive function for alpha-tocopherol (αtoc) in membranes is to protect polyunsaturated lipids against oxidation. Although the chemistry of the process is well established, the role played by molecular structure that we address here with atomistic molecular-dynamics simulations remains controversial. The simulations were run in the constant particle NPT ensemble on hydrated lipid bilayers composed of SDPC (1-stearoyl-2-docosahexaenoylphosphatidylcholine, 18:0-22:6PC) and SOPC (1-stearoyl-2-oleoylphosphatidylcholine, 18:0-18:1PC) in the presence of 20 mol % αtoc at 37°C. SDPC with SA (stearic acid) for the sn-1 chain and DHA (docosahexaenoic acid) for the sn-2 chain is representative of polyunsaturated phospholipids, while SOPC with OA (oleic acid) substituted for the sn-2 chain serves as a monounsaturated control. Solid-state (2)H nuclear magnetic resonance and neutron diffraction experiments provide validation. The simulations demonstrate that high disorder enhances the probability that DHA chains at the sn-2 position in SDPC rise up to the bilayer surface, whereby they encounter the chromanol group on αtoc molecules. This behavior is reflected in the van der Waals energy of interaction between αtoc and acyl chains, and illustrated by density maps of distribution for acyl chains around αtoc molecules that were constructed. An ability to more easily penetrate deep into the bilayer is another attribute conferred upon the chromanol group in αtoc by the high disorder possessed by DHA. By examining the trajectory of single molecules, we found that αtoc flip-flops across the SDPC bilayer on a submicrosecond timescale that is an order-of-magnitude greater than in SOPC. Our results reveal mechanisms by which the sacrificial hydroxyl group on the chromanol group can trap lipid peroxyl radicals within the interior and near the surface of a polyunsaturated membrane. At the same time, water-soluble reducing agents that regenerate αtoc can access the chromanol group when it locates at the surface.
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Affiliation(s)
- Xiaoling Leng
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana
| | - Jacob J Kinnun
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana
| | - Drew Marquardt
- Department of Physics, Brock University, St. Catharines, Ontario, Canada; Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Mikel Ghefli
- Department of Chemistry, Brock University, St. Catharines, Ontario, Canada
| | - Norbert Kučerka
- Canadian Neutron Beam Centre, National Research Council, Chalk River, Ontario, Canada; Faculty of Pharmacy, Comenius University, Bratislava, Slovakia
| | - John Katsaras
- Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee; Joint Institute for Neutron Sciences, Oak Ridge, Tennessee; Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee
| | - Jeffrey Atkinson
- Department of Chemistry, Brock University, St. Catharines, Ontario, Canada
| | - Thad A Harroun
- Department of Physics, Brock University, St. Catharines, Ontario, Canada
| | - Scott E Feller
- Department of Chemistry, Wabash College, Crawfordsville, Indiana
| | - Stephen R Wassall
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana.
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31
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Foglia F, Lawrence M, Barlow D. Studies of model biological and bio-mimetic membrane structure: Reflectivity vs diffraction, a critical comparison. Curr Opin Colloid Interface Sci 2015. [DOI: 10.1016/j.cocis.2015.08.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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32
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Neutron Scattering at the Intersection of Heart Health Science and Biophysics. J Cardiovasc Dev Dis 2015; 2:125-140. [PMID: 29371515 PMCID: PMC5753099 DOI: 10.3390/jcdd2020125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 05/25/2015] [Indexed: 01/04/2023] Open
Abstract
There is an urgent quest for improved heart health. Here, we review how neutron radiation can provide insight into the molecular basis of heart health. Lower cholesterol, a daily intake of aspirin and supplemental vitamin E are argued to all improve heart health. However, the mechanisms behind these common regimens, and others, are not entirely understood. It is not clear why a daily intake of aspirin can help some people with heart disease, and the benefits of vitamin E in the treatment of reperfusion injury have been heavily debated. The molecular impact of cholesterol in the body is still a hot topic. Neutron scattering experiments present a unique opportunity for biophysicists attempting to address these problems. We review some recently published studies that are advancing our understanding of how cholesterol, vitamin E and aspirin work at the molecular level, by studying the impact of these molecules on the cell membrane. These insights engage the broader health science community with new ways of thinking about these molecules.
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33
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Marquardt D, Kučerka N, Katsaras J, Harroun TA. α-Tocopherol's Location in Membranes Is Not Affected by Their Composition. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:4464-4472. [PMID: 25317847 DOI: 10.1021/la502605c] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
To this day, α-tocopherol's (aToc) role in humans is not well known. In previous studies, we have tried to connect aToc's biological function with its location in a lipid bilayer. In the present study, we have determined, by means of small-angle neutron diffraction, that not only is aToc's hydroxyl group located high in the membrane but its tail also resides far from the center of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayers. In addition, we located aToc's hydroxyl group above the lipid backbone in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE), 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine (POPS), and sphingomyelin bilayers, suggesting that aToc's location near the lipid-water interface may be a universal property of vitamin E. In light of these data, how aToc efficiently terminates lipid hydroperoxy radicals at the membrane center remains an open question.
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Affiliation(s)
- Drew Marquardt
- †Department of Physics, Brock University, St. Catharines, Ontario L2S 3A1, Canada
| | - Norbert Kučerka
- ‡National Research Council, Canadian Neutron Beam Centre, Chalk River, Ontario K0J 1J0, Canada
- §Department of Physical Chemistry of Drugs, Comenius University, 832 32 Bratislava, Slovakia
- ∥Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 141980 Dubna - Moscow Region, Russia
| | - John Katsaras
- †Department of Physics, Brock University, St. Catharines, Ontario L2S 3A1, Canada
- ⊥Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, United States
- #Joint Institute for Neutron Sciences, Oak Ridge, Tennessee37831-6453, United States
- ∇Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Thad A Harroun
- †Department of Physics, Brock University, St. Catharines, Ontario L2S 3A1, Canada
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34
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Shaikh SR, Wassall SR, Brown DA, Kosaraju R. N-3 Polyunsaturated Fatty Acids, Lipid Microclusters, and Vitamin E. CURRENT TOPICS IN MEMBRANES 2015; 75:209-31. [PMID: 26015284 DOI: 10.1016/bs.ctm.2015.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Increased consumption of long-chain marine n-3 polyunsaturated fatty acids (PUFA) has potential health benefits for the general population and for select clinical populations. However, several key limitations remain in making adequate dietary recommendations on n-3 PUFAs in addition to translating the fatty acids into clinical trials for select diseases. One major constraint is an incomplete understanding of the underlying mechanisms of action of n-3 PUFAs. In this review, we highlight studies to show n-3 PUFA acyl chains reorganize the molecular architecture of plasma membrane sphingolipid-cholesterol-enriched lipid rafts and potentially sphingolipid-rich cholesterol-free domains and cardiolipin-protein scaffolds in the inner mitochondrial membrane. We also discuss the possibility that the effects of n-3 PUFAs on membrane organization could be regulated by the presence of vitamin E (α-tocopherol), which is necessary to protect highly unsaturated acyl chains from oxidation. Finally, we propose the integrated hypothesis, based predominately on studies in lymphocytes, cancer cells, and model membranes, that the mechanism by which n-3 PUFAs disrupt signaling microclusters is highly dependent on the type of lipid species that incorporate n-3 PUFA acyl chains. The current evidence suggests that n-3 PUFA acyl chains disrupt lipid raft formation by incorporating primarily into phosphatidylethanolamines but can also incorporate into other lipid species of the lipidome.
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Affiliation(s)
- Saame Raza Shaikh
- Department of Biochemistry & Molecular Biology, East Carolina University, Greenville, NC, USA; Department of Microbiology and Immunology, East Carolina University, Greenville, NC, USA; East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
| | - Stephen R Wassall
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - David A Brown
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Physiology, East Carolina University, Greenville, NC, USA
| | - Rasagna Kosaraju
- Department of Biochemistry & Molecular Biology, East Carolina University, Greenville, NC, USA; East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
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35
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Afri M, Alexenberg C, Aped P, Bodner E, Cohen S, Ejgenburg M, Eliyahu S, Gilinsky-Sharon P, Harel Y, Naqqash ME, Porat H, Ranz A, Frimer AA. NMR-based molecular ruler for determining the depth of intercalants within the lipid bilayer. Chem Phys Lipids 2014; 184:105-18. [DOI: 10.1016/j.chemphyslip.2014.07.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Revised: 07/10/2014] [Accepted: 07/21/2014] [Indexed: 01/20/2023]
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36
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Natesan S, Lukacova V, Peng M, Subramaniam R, Lynch S, Wang Z, Tandlich R, Balaz S. Structure-based prediction of drug distribution across the headgroup and core strata of a phospholipid bilayer using surrogate phases. Mol Pharm 2014; 11:3577-95. [PMID: 25179490 PMCID: PMC4186683 DOI: 10.1021/mp5003366] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
![]()
Solvation of drugs in the core (C)
and headgroup (H) strata of
phospholipid bilayers affects their physiological transport rates
and accumulation. These characteristics, especially a complete drug
distribution profile across the bilayer strata, are tedious to obtain
experimentally, to the point that even simplified preferred locations
are only available for a few dozen compounds. Recently, we showed
that the partition coefficient (P) values in the
system of hydrated diacetyl phosphatidylcholine (DAcPC) and n-hexadecane (C16), as surrogates of the H- and C-strata
of the bilayer composed of the most abundant mammalian phospholipid,
PC, agree well with the preferred bilayer location of compounds. High P values are typical for lipophiles accumulating in the
core, and low P values are characteristic of cephalophiles
preferring the headgroups. This simple pattern does not hold for most
compounds, which usually have more even distribution and may also
accumulate at the H/C interface. To model complete distribution, the
correlates of solvation energies are needed for each drug state in
the bilayer: (1) for the H-stratum it is the DAcPC/W P value, calculated as the ratio of the C16/W and C16/DAcPC (W for
water) P values; (2) for the C-stratum, the C16/W P value; (3) for the H/C interface, the P values for all plausible molecular poses are characterized using
the fragment DAcPC/W and C16/W solvation parameters for the parts
of the molecule embedded in the H- and C-strata, respectively. The
correlates, each scaled by two Collander coefficients, were used in
a nonlinear, mass-balance based model of intrabilayer distribution,
which was applied to the easily measurable overall P values of compounds in the DMPC (M = myristoyl) bilayers and monolayers
as the dependent variables. The calibrated model for 107 neutral compounds
explains 94% of experimental variance, achieves similar cross-validation
levels, and agrees well with the nontrivial, experimentally determined
bilayer locations for 27 compounds. The resulting structure-based
prediction system for intrabilayer distribution will facilitate more
realistic modeling of passive transport and drug interactions with
those integral membrane proteins, which have the binding sites located
in the bilayer, such as some enzymes, influx and efflux transporters,
and receptors. If only overall bilayer accumulation is of interest,
the 1-octanol/W P values suffice to model the studied
set.
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Affiliation(s)
- Senthil Natesan
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences , Vermont Campus, Colchester, Vermont 05446, United States
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37
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Garrec J, Monari A, Assfeld X, Mir LM, Tarek M. Lipid Peroxidation in Membranes: The Peroxyl Radical Does Not "Float". J Phys Chem Lett 2014; 5:1653-1658. [PMID: 26270361 DOI: 10.1021/jz500502q] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Lipid peroxidation is a fundamental phenomenon in biology and medicine involved in a wide range of diseases. Some key microscopic aspects of this reaction in cell membranes are still poorly studied. In particular, it is commonly accepted that the propagation of the radical reaction in lipid bilayers is hampered by the rapid diffusion of peroxyl intermediates toward the water interface, that is, out of the reaction region. We investigated the validity of this "floating peroxyl radical" hypothesis by means of molecular modeling. Combining quantum calculations of model systems and atomistic simulations of lipid bilayers containing lipid oxidation products, we show that the peroxyl radical does not "float" at the surface of the membrane. Instead, it remains located quite deep inside the bilayer. In light of our findings, several critical aspects of biological membranes' peroxidation, such as their protection mechanisms, need to be revisited. Our data moreover help in the design of more efficient antioxidants, localized within reach of the reaction propagating radical.
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Affiliation(s)
- Julian Garrec
- †Théorie-Modélisation-Simulation, SRSMC, CNRS, Vandoeuvre-lès-Nancy F-54506, France
- ‡Théorie-Modélisation-Simulation, SRSMC, Université de Lorraine, Vandoeuvre-lès-Nancy F-54506, France
| | - Antonio Monari
- †Théorie-Modélisation-Simulation, SRSMC, CNRS, Vandoeuvre-lès-Nancy F-54506, France
- ‡Théorie-Modélisation-Simulation, SRSMC, Université de Lorraine, Vandoeuvre-lès-Nancy F-54506, France
| | - Xavier Assfeld
- †Théorie-Modélisation-Simulation, SRSMC, CNRS, Vandoeuvre-lès-Nancy F-54506, France
- ‡Théorie-Modélisation-Simulation, SRSMC, Université de Lorraine, Vandoeuvre-lès-Nancy F-54506, France
| | - Lluis M Mir
- ¶Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, Université Paris-Sud, UMR 8203, Orsay F-91405, France
- §Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, CNRS, UMR 8203, Orsay F-91405, France
- ∥Laboratoire de Vectorologie et Thérapeutiques Anticancéreuses, Gustave Roussy, UMR 8203, Villjuif F-94805, France
| | - Mounir Tarek
- †Théorie-Modélisation-Simulation, SRSMC, CNRS, Vandoeuvre-lès-Nancy F-54506, France
- ‡Théorie-Modélisation-Simulation, SRSMC, Université de Lorraine, Vandoeuvre-lès-Nancy F-54506, France
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