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Labecka N, Szczepanczyk M, Mojumdar E, Sparr E, Björklund S. Unraveling UVB effects: Catalase activity and molecular alterations in the stratum corneum. J Colloid Interface Sci 2024; 666:176-188. [PMID: 38593652 DOI: 10.1016/j.jcis.2024.03.200] [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: 12/21/2023] [Revised: 03/25/2024] [Accepted: 03/29/2024] [Indexed: 04/11/2024]
Abstract
AIM Ultraviolet B (UVB) radiation can compromise the functionality of the skin barrier through various mechanisms. We hypothesize that UVB induce photochemical alterations in the components of the outermost layer of the skin, known as the stratum corneum (SC), and modulate its antioxidative defense mechanisms. Catalase is a well-known antioxidative enzyme found in the SC where it acts to scavenge reactive oxygen species. However, a detailed characterization of acute UVB exposure on the activity of native catalase in the SC is lacking. Moreover, the effects of UVB irradiation on the molecular dynamics and organization of the SC keratin and lipid components remain unclear. Thus, the aim of this work is to characterize consequences of UVB exposure on the structural and antioxidative properties of catalase, as well as on the molecular and global properties of the SC matrix surrounding the enzyme. EXPERIMENTS The effect of UVB irradiation on the catalase function is investigated by chronoamperometry with a skin covered oxygen electrode, which probes the activity of native catalase in the SC matrix. Circular dichroism is used to explore changes of the catalase secondary structure, and gel electrophoresis is used to detect fragmentation of the enzyme following the UVB exposure. UVB induced alterations of the SC molecular dynamics and structural features of the SC barrier, as well as its water sorption behavior, are investigated by a complementary set of techniques, including natural abundance 13C polarization transfer solid-state NMR, wide-angle X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, and dynamic vapor sorption microbalance. FINDINGS The findings show that UVB exposure impairs the antioxidative function of catalase by deactivating both native catalase in the SC matrix and lyophilized catalase. However, UVB radiation does not alter the secondary structure of the catalase nor induce any observable enzyme fragmentation, which otherwise could explain deactivation of its function. NMR measurements on SC samples show a subtle increase in the molecular mobility of the terminal segments of the SC lipids, accompanied by a decrease in the mobility of lipid chain trans-gauche conformers after high doses of UVB exposure. At the same time, the NMR data suggest increased rigidity of the polypeptide backbone of the keratin filaments, while the molecular mobility of amino acid residues in random coil domains of keratin remain unaffected by UVB irradiation. The FTIR data show a consistent decrease in absorbance associated with lipid bond vibrations, relative to the main protein bands. Collectively, the NMR and FTIR data suggest a small modification in the composition of fluid and solid phases of the SC lipid and protein components after UVB exposure, unrelated to the hydration capacity of the SC tissue. To conclude, UVB deactivation of catalase is anticipated to elevate oxidative stress of the SC, which, when coupled with subtle changes in the molecular characteristics of the SC, may compromise the overall skin health and elevate the likelihood of developing skin disorders.
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Affiliation(s)
- Nikol Labecka
- Department of Biomedical Science, Malmö University, SE-205 06 Malmö, Sweden; Biofilms Research Center for Biointerfaces, Malmö University, SE-205 06 Malmö, Sweden; Division of Physical Chemistry, Chemistry Department, Lund University, SE-221 00 Lund, Sweden
| | - Michal Szczepanczyk
- Department of Biomedical Science, Malmö University, SE-205 06 Malmö, Sweden; Biofilms Research Center for Biointerfaces, Malmö University, SE-205 06 Malmö, Sweden
| | - Enamul Mojumdar
- Department of Biomedical Science, Malmö University, SE-205 06 Malmö, Sweden; Biofilms Research Center for Biointerfaces, Malmö University, SE-205 06 Malmö, Sweden; Division of Physical Chemistry, Chemistry Department, Lund University, SE-221 00 Lund, Sweden; CR Competence AB, Box 124, 22100 Lund, Sweden
| | - Emma Sparr
- Division of Physical Chemistry, Chemistry Department, Lund University, SE-221 00 Lund, Sweden
| | - Sebastian Björklund
- Department of Biomedical Science, Malmö University, SE-205 06 Malmö, Sweden; Biofilms Research Center for Biointerfaces, Malmö University, SE-205 06 Malmö, Sweden.
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Rowlands LJ, Marks A, Sanderson JM, Law RV. 17O NMR spectroscopy as a tool to study hydrogen bonding of cholesterol in lipid bilayers. Chem Commun (Camb) 2021; 56:14499-14502. [PMID: 33150883 DOI: 10.1039/d0cc05466f] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cholesterol is a crucial component of biological membranes and can interact with other membrane components through hydrogen bonding. NMR spectroscopy has been used previously to investigate this bonding, however this study represents the first 17O NMR spectroscopy study of isotopically enriched cholesterol. We demonstrate the 17O chemical shift is dependent on hydrogen bonding, providing a novel method for the study of cholesterol in bilayers.
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Affiliation(s)
- Lucy J Rowlands
- Institute of Chemical Biology, Imperial College London, Molecular Sciences Research Hub, W12 0BZ London, UK.
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3
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Chen Y, Zhang C, Xie J, Li H, Dai W, Deng Q, Wang S. Covalent organic frameworks as a sensing platform for water in organic solvent over a broad concentration range. Anal Chim Acta 2020; 1109:114-121. [PMID: 32252894 DOI: 10.1016/j.aca.2020.03.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 02/25/2020] [Accepted: 03/02/2020] [Indexed: 01/07/2023]
Abstract
A highly crystalline covalent organic frameworks (COFs) formed by condensation reaction between 1, 3, 5-tris (4-aminophenyl) benzene and 4, 4'-biphenyldicarboxaldehyde is utilized as a sensing platform for water in organic solvent over a broad concentration range. The resulting COFs exhibits brilliant fluorescence in various organic solvents such as methanol, DMF, acetonitrile and ethanol, moreover its fluorescence intensity has a significant and rapid response to the content of water in organic solvent over a broad concentration range. The broadest sensing range is achieved over 7%-70% (v/v) for water in DMF, and the lowest limit of detection is 0.042% (v/v) for water in methanol among the investigated organic solvents. The superior properties of the sensing platform expand the application ranges of COFs and endow the resulting COFs with a great prospect in practical applications for highly efficient detecting water in organic solvent.
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Affiliation(s)
- Yujie Chen
- College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Caiyun Zhang
- College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Jiangyang Xie
- College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Haijie Li
- College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Wenjing Dai
- College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Qiliang Deng
- College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin, 300457, China.
| | - Shuo Wang
- College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin, 300457, China; Tianjin Key Laboratory of Food Science and Health, School of Medicine, Nankai University, Tianjin, 300071, China.
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4
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Wu D, Carillo KJD, Tsai S, Shie J, Tzou DM. Solid‐state nuclear magnetic resonance investigation of neurosteroid compounds and magnesium interactions. J CHIN CHEM SOC-TAIP 2019. [DOI: 10.1002/jccs.201800458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Danni Wu
- Chemical Engineering Department, National Taiwan University of Science and Technology Taipei Taiwan
| | - Kathleen Joyce D. Carillo
- Taiwan International Graduate Program of Sustainable Chemical Science and Technology Taipei Taiwan
- Department of Applied ChemistryNational Chiao Tung University Hsinchu Taiwan
- Institute of ChemistryAcademia Sinica, Nankang Taipei Taiwan
| | - Shen‐Long Tsai
- Chemical Engineering Department, National Taiwan University of Science and Technology Taipei Taiwan
| | - Jiun‐Jie Shie
- Taiwan International Graduate Program of Sustainable Chemical Science and Technology Taipei Taiwan
- Institute of ChemistryAcademia Sinica, Nankang Taipei Taiwan
| | - Der‐Lii M. Tzou
- Institute of ChemistryAcademia Sinica, Nankang Taipei Taiwan
- Department of Applied ChemistryNational Chia‐Yi University Chia‐Yi Taiwan
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5
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Dissanayake AA, Wagner CM, Nair MG. Chemical Characterization of Lipophilic Constituents in the Skin of Migratory Adult Sea Lamprey from the Great Lakes Region. PLoS One 2016; 11:e0168609. [PMID: 27992570 PMCID: PMC5167404 DOI: 10.1371/journal.pone.0168609] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 12/02/2016] [Indexed: 11/23/2022] Open
Abstract
The sea lamprey (Petromzons marinus) is an invasive ectoparasite of large-bodied fishes that adversely affects the fishing industry and ecology of the Laurentian Great Lakes. Lipid content in the whole sea lamprey and muscles, liver and kidney of metamorphosing larval stages has been reported. Similarly, the fatty acid profile of the rope tissues of sexually-mature male sea lampreys has also been reported. The average body weight of a sub-adult migratory sea lamprey is 250 g, which includes 14.4% skin (36 g). Our preliminary extraction data of an adult sea lamprey skin revealed that it contained approximately 8.5% of lipophilic compounds. Lamprey skin is home to a naturally aversive compound (an alarm cue) that is being developed into a repellent for use in pest management. As part of an ongoing investigation to identify the chemical structure of the sea lamprey alarm cue, we extracted the skin with water and methanol, respectively. The methanolic extract (1.55%) contained exclusively lipophilic compounds and did not include the alarm cue. We chemically characterized all compounds present in the methanolic extract as cholesterol esters (CE), tri- and di-glycerides (TG and DG), cholesterol, free fatty acids (FFA) and minor amounts of plasticizers. The free fatty acids fraction was composed of saturated (41.8%), monounsaturated (40.7%) and polyunsaturated (17.4%) fatty acids, respectively. The plasticizers characterized were phthalate and benzoate and found to be 0.95 mg and 2.54 mg, respectively, per adult sea lamprey skin. This is the first report of the chemical characterization of all the lipophilic constituents in the skin of sub-adult migratory sea lamprey. The CEs isolated and characterized from sea lamprey skin are also for the first time.
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Affiliation(s)
- Amila A. Dissanayake
- Department of Horticulture, Michigan State University, East Lansing, Michigan, United States of America
| | - C. Michael Wagner
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, Michigan, United States of America
| | - Muraleedharan G. Nair
- Department of Horticulture, Michigan State University, East Lansing, Michigan, United States of America
- College of Food and Agriculture Sciences, Chair of Date Palm Research, King Saud University, Riyadh, Saudi Arabia
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6
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The effects of polar excipients transcutol and dexpanthenol on molecular mobility, permeability, and electrical impedance of the skin barrier. J Colloid Interface Sci 2016; 479:207-220. [DOI: 10.1016/j.jcis.2016.06.054] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 06/21/2016] [Accepted: 06/21/2016] [Indexed: 11/16/2022]
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7
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Wang J, Zhang Z, Zhao W, Wang L, Yang J. Heating and temperature gradients of lipid bilayer samples induced by RF irradiation in MAS solid-state NMR experiments. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2016; 54:753-759. [PMID: 27161041 DOI: 10.1002/mrc.4450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/16/2016] [Accepted: 04/18/2016] [Indexed: 05/15/2023]
Abstract
The MAS solid-state NMR has been a powerful technique for studying membrane proteins within the native-like lipid bilayer environment. In general, RF irradiation in MAS NMR experiments can heat and potentially destroy expensive membrane protein samples. However, under practical MAS NMR experimental conditions, detailed characterization of RF heating effect of lipid bilayer samples is still lacking. Herein, using 1 H chemical shift of water for temperature calibration, we systematically study the dependence of RF heating on hydration levels and salt concentrations of three lipids in MAS NMR experiments. Under practical 1 H decoupling conditions used in biological MAS NMR experiments, three lipids show different dependence of RF heating on hydration levels as well as salt concentrations, which are closely associated with the properties of lipids. The maximum temperature elevation of about 10 °C is similar for the three lipids containing 200% hydration, which is much lower than that in static solid-state NMR experiments. The RF heating due to salt is observed to be less than that due to hydration, with a maximum temperature elevation of less than 4 °C in the hydrated samples containing 120 mmol l-1 of salt. Upon RF irradiation, the temperature gradient across the sample is observed to be greatly increased up to 20 °C, as demonstrated by the remarkable broadening of 1 H signal of water. Based on detailed characterization of RF heating effect, we demonstrate that RF heating and temperature gradient can be significantly reduced by decreasing the hydration levels of lipid bilayer samples from 200% to 30%. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Jing Wang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhengfeng Zhang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Weijing Zhao
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Liying Wang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Jun Yang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
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8
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Tanasescu R, Lanz MA, Mueller D, Tassler S, Ishikawa T, Reiter R, Brezesinski G, Zumbuehl A. Vesicle Origami and the Influence of Cholesterol on Lipid Packing. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:4896-4903. [PMID: 27142706 DOI: 10.1021/acs.langmuir.6b01143] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The artificial phospholipid Pad-PC-Pad was analyzed in 2D (monolayers at the air/water interface) and 3D (aqueous lipid dispersions) systems. In the gel phase, the two leaflets of a Pad-PC-Pad bilayer interdigitate completely, and the hydrophobic bilayer region has a thickness comparable to the length of a single phospholipid acyl chain. This leads to a stiff membrane with no spontaneous curvature. Forced into a vesicular structure, Pad-PC-Pad has faceted geometry, and in its extreme form, tetrahedral vesicles were found as predicted a decade ago. Above the main transition temperature, a noninterdigitated Lα phase with fluid chains has been observed. The addition of cholesterol leads to a slight decrease of the main transition temperature and a gradual decrease in the transition enthalpy until the transition vanishes at 40 mol % cholesterol in the mixture. Additionally, cholesterol pulls the chains apart, and a noninterdigitated gel phase is observed. In monolayers, cholesterol has an ordering effect on liquid-expanded phases and disorders condensed phases. The wavenumbers of the methylene stretching vibration indicate the formation of a liquid-ordered phase in mixtures with 40 mol % cholesterol.
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Affiliation(s)
- Radu Tanasescu
- Department of Chemistry, University of Fribourg , Chemin du Musée 9, 1700 Fribourg, Switzerland
| | - Martin A Lanz
- Department of Chemistry, University of Fribourg , Chemin du Musée 9, 1700 Fribourg, Switzerland
| | - Dennis Mueller
- Department of Chemistry, University of Fribourg , Chemin du Musée 9, 1700 Fribourg, Switzerland
| | - Stephanie Tassler
- Max Planck Institute of Colloids and Interfaces , Science Park Potsdam-Golm, 14476 Potsdam, Germany
| | - Takashi Ishikawa
- Paul Scherrer Institute (PSI), OFLB/010 5232 Villigen PSI, Switzerland
| | - Renate Reiter
- Experimental Polymer Physics, University of Freiburg , Hermann Herder Strasse 3, 79104 Freiburg, Germany
- Freiburg Centre for Interactive Materials and Bioinspired Technologies (FIT), 79110 Freiburg, Germany
| | - Gerald Brezesinski
- Max Planck Institute of Colloids and Interfaces , Science Park Potsdam-Golm, 14476 Potsdam, Germany
| | - Andreas Zumbuehl
- Department of Chemistry, University of Fribourg , Chemin du Musée 9, 1700 Fribourg, Switzerland
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9
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Davis JH, Komljenović I. Nuclear Overhauser effect as a probe of molecular structure, dynamics and order of axially reorienting molecules in membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:295-303. [DOI: 10.1016/j.bbamem.2015.11.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 10/21/2015] [Accepted: 11/18/2015] [Indexed: 10/22/2022]
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10
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Carillo KD, Arco S, Wang CC, Tzou DLM. Solid-state NMR investigation of effect of fluorination and methylation on prednisolone conformation. Steroids 2015; 104:263-9. [PMID: 26476185 DOI: 10.1016/j.steroids.2015.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Revised: 09/11/2015] [Accepted: 10/12/2015] [Indexed: 10/22/2022]
Abstract
Prednisolone (Prd) is a polymorphous synthetic corticosteroid that has three crystalline forms mediated by different solvents. In this study, we have demonstrated that solid-state {(1)H}(13)C cross-polarization/magic angle spinning (CP/MAS) NMR spectroscopy is able to resolve the effects of methylation and fluorination on the conformation of the steroidal rings in Prd. Two compounds were chosen for the study, 6-α-methylprednisolone (Prd-6M) and 6-α-fluoroprednisolone (Prd-6F). The (13)C signals of Prd-6F showed primarily doublet patterns, with splittings of 40-380 Hz, indicating multiple ring conformations, whereas the (13)C signals of Prd and Prd-6M exhibited a singlet pattern, indicating a unique conformation. Using evidence from chemical shift deviation and anisotropy analysis, we have demonstrated by solid-state NMR that Prd-6F adopts two different steroidal ring conformations that are different from that of Prd-6M, and less similar to that of unsubstituted Prd.
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Affiliation(s)
- Kathleen D Carillo
- University of the Philippines Diliman, Diliman, Quezon City 1100, Philippines; Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Susan Arco
- University of the Philippines Diliman, Diliman, Quezon City 1100, Philippines
| | - Cheng-Chung Wang
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC.
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11
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Gater DL, Saurel O, Iordanov I, Liu W, Cherezov V, Milon A. Two classes of cholesterol binding sites for the β2AR revealed by thermostability and NMR. Biophys J 2015; 107:2305-12. [PMID: 25418299 DOI: 10.1016/j.bpj.2014.10.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 09/19/2014] [Accepted: 10/09/2014] [Indexed: 11/24/2022] Open
Abstract
Cholesterol binding to G protein-coupled receptors (GPCRs) and modulation of their activities in membranes is a fundamental issue for understanding their function. Despite the identification of cholesterol binding sites in high-resolution x-ray structures of the ?2 adrenergic receptor (β2AR) and other GPCRs, the binding affinity of cholesterol for this receptor and exchange rates between the free and bound cholesterol remain unknown. In this study we report the existence of two classes of cholesterol binding sites in β2AR. By analyzing the β2AR unfolding temperature in lipidic cubic phase (LCP) as a function of cholesterol concentration we observed high-affinity cooperative binding of cholesterol with sub-nM affinity constant. In contrast, saturation transfer difference (STD) NMR experiments revealed the existence of a second class of cholesterol binding sites, in fast exchange on the STD NMR timescale. Titration of the STD signal as a function of cholesterol concentration provided a lower limit of 100 mM for their dissociation constant. However, these binding sites are specific for both cholesterol and β2AR, as shown with control experiments using ergosterol and a control membrane protein (KpOmpA). We postulate that this specificity is mediated by the high-affinity bound cholesterol molecules and propose the formation of transient cholesterol clusters around the high-affinity binding sites.
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Affiliation(s)
- Deborah L Gater
- Institute of Pharmacology and Structural Biology - UMR 5089, CNRS and Université de Toulouse - UPS, 205 Route de Narbonne, 31077 Toulouse, France; Khalifa University of Science, Technology and Research, P.O. Box 127788, Abu Dhabi, UAE
| | - Olivier Saurel
- Institute of Pharmacology and Structural Biology - UMR 5089, CNRS and Université de Toulouse - UPS, 205 Route de Narbonne, 31077 Toulouse, France
| | - Iordan Iordanov
- Institute of Pharmacology and Structural Biology - UMR 5089, CNRS and Université de Toulouse - UPS, 205 Route de Narbonne, 31077 Toulouse, France
| | - Wei Liu
- Department of Integrative Structural and Computational Biology, Scripps Research Institute, La Jolla, California
| | - Vadim Cherezov
- Department of Integrative Structural and Computational Biology, Scripps Research Institute, La Jolla, California.
| | - Alain Milon
- Institute of Pharmacology and Structural Biology - UMR 5089, CNRS and Université de Toulouse - UPS, 205 Route de Narbonne, 31077 Toulouse, France.
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12
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Wang D, Chen M, Chein RJ, Ching WM, Hung CH, Tzou DLM. Cation ion specifically induces a conformational change in trans-dehydroandrosterone - a solid-state NMR study. Steroids 2015; 96:73-80. [PMID: 25637678 DOI: 10.1016/j.steroids.2015.01.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 01/09/2015] [Accepted: 01/19/2015] [Indexed: 11/23/2022]
Abstract
In this work, we demonstrated that calcium (Ca(+2)) is able to induce a conformational change in trans-dehydroandrosterone (DHEA). To this respect, solid-state NMR spectroscopy was applied to a series of DHEA molecules that were incubated with Ca(+2) under different concentrations. The high-resolution (13)C NMR spectra of the DHEA/Ca(+2) mixtures exhibited two distinct sets of signals; one was attributed to DHEA in the free form, and the second set was due to the DHEA/Ca(+2) complex. Based on chemical shift isotropy and anisotropy analyses, we postulated that Ca(+2) might have associated with the oxygen attached to C17 via a lone-pair of electrons, which induced a conformational change in DHEA. Apart from Ca(+2), we also incubated DHEA with magnesium (Mg(+2)) to determine whether Mg(+2) was able to interact with DHEA in a similar manner to Ca(+2). We found that Mg(+2) was able to induce a conformational change in DHEA deviated from that of Ca(+2). These solid-state NMR observations indicate that DHEA is able to interact with cations, such as Mg(+2) and Ca(+2), with specificity.
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Affiliation(s)
- Darong Wang
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Meiman Chen
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Rong-Jie Chein
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Wei-Min Ching
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Chen-Hsiung Hung
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC.
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13
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Membrane properties of cholesterol analogs with an unbranched aliphatic side chain. Chem Phys Lipids 2014; 184:1-6. [PMID: 25173446 DOI: 10.1016/j.chemphyslip.2014.08.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 08/07/2014] [Accepted: 08/21/2014] [Indexed: 11/21/2022]
Abstract
The interactions between cholesterol and other membrane molecules determine important membrane properties. It was shown that even small changes in the molecular structure of cholesterol have a crucial influence on these interactions. We recently reported that in addition to alterations in the tetracyclic ring structure, the iso-branched side chain of cholesterol also has a significant impact on membrane properties (Scheidt et al., 2013). Here we used synthetic cholesterol analogs to investigate the influence of an unbranched aliphatic side chain of different length. The (2)H NMR order parameter of the phospholipid chains and therefore the molecular packing of the phospholipid molecules shows a significant dependence on the sterol's alkyl side chain length, while, membrane permeation studied by a dithionite ion permeation assay and lateral diffusion measured by (1)H MAS pulsed field gradient NMR are less influenced. To achieve the same molecular packing effect similar to that of an iso-branched aliphatic side chain, a longer unbranched side chain (n-dodecyl instead of n-octyl) at C17 of cholesterol is required. Obviously, sterols having a branched iso-alkyl chain with two terminal methyl groups exhibit altered cholesterol-phospholipid interactions compared to analogous molecules with a straight unbranched chain.
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14
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Mouret L, Da Costa G, Bondon A. Sterols associated with small unilamellar vesicles (SUVs): intrinsic mobility role for 1H NMR detection. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2014; 52:339-344. [PMID: 24691941 DOI: 10.1002/mrc.4069] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 02/27/2014] [Accepted: 03/11/2014] [Indexed: 06/03/2023]
Abstract
Small unilamellar vesicles (SUVs) of phospholipids are often used as a membrane model system for studying the interaction of molecules. When using NMR under the standard liquid-state conditions, SUV phospholipid proton spectra can be recorded, exhibiting sharp signals. This is not only because of the fast vesicular tumbling but also because of the combination of this tumbling with the individual motion of the lipids inside the bilayer. This appears evident because addition of cholesterol is responsible of broader resonances because of the slowing down of the lipid motion. On the other hand, no (1)H signal is detected for cholesterol in the bilayer. This lack of detection of the inserted molecules explains why generally SUVs are not considered as a good model for NMR studies under the standard liquid-state conditions. Here, we use two other sterols in order to demonstrate that an increase of the molecular mobility inside the bilayer could allow the detection of their proton resonances. For desmosterol and lanosterol, which show higher mobility inside the bilayer, with increasing lateral diffusion rates, (1)H sterol signals are detected in contrast to cholesterol. For the fast diffusing lanosterol, no significant improvement in detection is observed using deuterated lipids, demonstrating that homonuclear dipolar coupling is fully averaged out. Furthermore, in the case of low mobility such as for cholesterol, the use of a fast magic angle spinning probe is shown to be efficient to recover the full proton spectrum.
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Affiliation(s)
- Liza Mouret
- Université de Rennes 1, UMR CNRS 6226, ICMV, PRISM Biosit, Campus de Villejean, 35043, Rennes Cedex, France
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15
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Fritzsching KJ, Kim J, Holland GP. Probing lipid–cholesterol interactions in DOPC/eSM/Chol and DOPC/DPPC/Chol model lipid rafts with DSC and 13C solid-state NMR. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:1889-98. [DOI: 10.1016/j.bbamem.2013.03.028] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 03/25/2013] [Accepted: 03/28/2013] [Indexed: 10/27/2022]
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16
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Gater DL, Réat V, Czaplicki G, Saurel O, Jolibois F, Cherezov V, Milon A. Hydrogen bonding of cholesterol in the lipidic cubic phase. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:8031-8038. [PMID: 23763339 PMCID: PMC3758441 DOI: 10.1021/la401351w] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The addition of cholesterol to the monoolein-based lipidic cubic phase (LCP) has been instrumental in obtaining high-resolution crystal structures of several G protein-coupled receptors. Here, we report the use of high-resolution magic angle spinning NMR spectroscopy to record and assign the isotropic (13)C chemical shifts of cholesterol in lipidic lamellar and cubic phases at different hydration levels with monoolein and chain-deuterated DMPC as host lipids. The hydrogen-bonding patterns of cholesterol in these phases were determined from the NMR data by quantum chemical calculations. The results are consistent with the normal orientation of cholesterol in lipid bilayers and with the cholesterol hydroxyl group located at the hydrophobic/hydrophilic interface. The (13)C chemical shifts of cholesterol are mostly affected by the host lipid identity with little or no dependency on the hydration (20% vs 40%) or the phase identity (lamellar vs LCP). In chain-deuterated DMPC bilayers, the hydroxyl group of cholesterol forms most of its hydrogen bonds with water, while in monoolein bilayers it predominately interacts with monoolein. Such differences in the hydrogen-bonding network of cholesterol may have implications for the design of experiments in monoolein-based LCP.
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Affiliation(s)
- Deborah L. Gater
- Institut de Pharmacologie et de Biologie Structurale, UMR 5089 CNRS - Université de Toulouse, UPS, BP 64182, 205 route de Narbonne, 31077 Toulouse Cedex04 (France)
| | - Valérie Réat
- Institut de Pharmacologie et de Biologie Structurale, UMR 5089 CNRS - Université de Toulouse, UPS, BP 64182, 205 route de Narbonne, 31077 Toulouse Cedex04 (France)
| | - Georges Czaplicki
- Institut de Pharmacologie et de Biologie Structurale, UMR 5089 CNRS - Université de Toulouse, UPS, BP 64182, 205 route de Narbonne, 31077 Toulouse Cedex04 (France)
| | - Olivier Saurel
- Institut de Pharmacologie et de Biologie Structurale, UMR 5089 CNRS - Université de Toulouse, UPS, BP 64182, 205 route de Narbonne, 31077 Toulouse Cedex04 (France)
| | - Franck Jolibois
- Laboratoire de Physique et Chimie des Nano Objets, UMR 5215, IRSAMC -Université de Toulouse, UPS, 135 Avenue de Rangueil, 31077 Toulouse Cedex04 (France)
| | - Vadim Cherezov
- Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla CA 92037 (USA)
| | - Alain Milon
- Institut de Pharmacologie et de Biologie Structurale, UMR 5089 CNRS - Université de Toulouse, UPS, BP 64182, 205 route de Narbonne, 31077 Toulouse Cedex04 (France)
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17
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Björklund S, Nowacka A, Bouwstra JA, Sparr E, Topgaard D. Characterization of stratum corneum molecular dynamics by natural-abundance ¹³C solid-state NMR. PLoS One 2013; 8:e61889. [PMID: 23626744 PMCID: PMC3633950 DOI: 10.1371/journal.pone.0061889] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 03/15/2013] [Indexed: 11/19/2022] Open
Abstract
Despite the enormous potential for pharmaceutical applications, there is still a lack of understanding of the molecular details that can contribute to increased permeability of the stratum corneum (SC). To investigate the influence of hydration and heating on the SC, we record the natural-abundance (13)C signal of SC using polarization transfer solid-state NMR methods. Resonance lines from all major SC components are assigned. Comparison of the signal intensities obtained with the INEPT and CP pulse sequences gives information on the molecular dynamics of SC components. The majority of the lipids are rigid at 32°C, and those lipids co-exist with a small pool of mobile lipids. The ratio between mobile and rigid lipids increases with hydration. An abrupt change of keratin filament dynamics occurs at RH = 80-85%, from completely rigid to a structure with rigid backbone and mobile protruding terminals. Heating has a strong effect on the lipid mobility, but only a weak influence on the keratin filaments. The results provide novel molecular insight into how the SC constituents are affected by hydration and heating, and improve the understanding of enhanced SC permeability, which is associated with elevated temperatures and SC hydration.
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Affiliation(s)
- Sebastian Björklund
- Division of Physical Chemistry, Center for Chemistry and Chemical Engineering, Lund University, Lund, Sweden.
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18
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Ferreira TM, Coreta-Gomes F, Ollila OHS, Moreno MJ, Vaz WLC, Topgaard D. Cholesterol and POPC segmental order parameters in lipid membranes: solid state 1H-13C NMR and MD simulation studies. Phys Chem Chem Phys 2012; 15:1976-89. [PMID: 23258433 DOI: 10.1039/c2cp42738a] [Citation(s) in RCA: 141] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The concentration of cholesterol in cell membranes affects membrane fluidity and thickness, and might regulate different processes such as the formation of lipid rafts. Since interpreting experimental data from biological membranes is rather intricate, investigations on simple models with biological relevance are necessary to understand the natural systems. We study the effect of cholesterol on the molecular structure of multi-lamellar vesicles (MLVs) composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), a phospholipid ubiquitous in cell membranes, with compositions in the range 0-60 mol% cholesterol. Order parameters, |S(CH)|, are experimentally determined by using (1)H-(13)C solid-state nuclear magnetic resonance (NMR) spectroscopy with segmental detail for all parts of both the cholesterol and POPC molecules, namely the ring system and alkyl chain of the sterol, as well as the glycerol backbone, choline headgroup and the sn-1 and sn-2 acyl chains of POPC. With increasing cholesterol concentration the acyl chains gradually adopt a more extended conformation while the orientation and dynamics of the polar groups are rather unaffected. Additionally, we perform classical molecular dynamics simulations on virtual bilayers mimicking the POPC-cholesterol MLVs investigated by NMR. Good agreement between experiments and simulations is found for the cholesterol alignment in the bilayer and for the |S(CH)| profiles of acyl chains below 15 mol% cholesterol. Deviations occur for the choline headgroup and glycerol backbone parts of POPC, as well as for the phospholipid and cholesterol alkyl chains at higher cholesterol concentrations. The unprecedented detail of the NMR data enables a more complete comparison between simulations and experiments on POPC-cholesterol bilayers and may aid in developing more realistic model descriptions of biological membranes.
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19
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Thompson AA, Liu JJ, Chun E, Wacker D, Wu H, Cherezov V, Stevens RC. GPCR stabilization using the bicelle-like architecture of mixed sterol-detergent micelles. Methods 2011; 55:310-7. [PMID: 22041719 DOI: 10.1016/j.ymeth.2011.10.011] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 10/18/2011] [Accepted: 10/18/2011] [Indexed: 12/30/2022] Open
Abstract
The biophysical characterization of purified membrane proteins typically requires detergent mediated extraction from native lipid membrane environments. In the case of human G protein-coupled receptors (GPCRs), this process has been complicated by their conformational heterogeneity and the general lack of understanding the composition and interactions within the diverse human cellular membrane environment. Several successful GPCR structure determination efforts have shown that the addition of cholesterol analogs is often critical for maintaining protein stability. We have identified sterols that substantially increase the stability of the NOP receptor (ORL-1), a member of the opioid GPCR family, in a mixed micelle environment. Using dynamic light scattering and small-angle X-ray scattering, we have determined that the most thermal stabilizing sterol, cholesteryl hemisuccinate, induces the formation of a bicelle-like micelle architecture when mixed with dodecyl maltoside detergent. Together with mutagenesis studies and recent GPCR structures, our results provide indications that stabilization is attained through a combination of specific sterol binding to GPCRs and modulation of micelle morphology.
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Affiliation(s)
- Aaron A Thompson
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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20
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Howell SC, Mittal R, Huang L, Travis B, Breyer RM, Sanders CR. CHOBIMALT: a cholesterol-based detergent. Biochemistry 2011; 49:9572-83. [PMID: 20919740 DOI: 10.1021/bi101334j] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Cholesterol and its hemisuccinate and sulfate derivatives are widely used in studies of purified membrane proteins but are difficult to solubilize in aqueous solution, even in the presence of detergent micelles. Other cholesterol derivatives do not form conventional micelles and lead to viscous solutions. To address these problems, a cholesterol-based detergent, CHOBIMALT, has been synthesized and characterized. At concentrations above 3−4 μM, CHOBIMALT forms micelles without the need for elevated temperatures or sonic disruption. Diffusion and fluorescence measurements indicated that CHOBIMALT micelles are large (210±30 kDa). The ability to solubilize a functional membrane protein was explored using a G-protein coupled receptor, the human kappa opioid receptor type 1 (hKOR1). While CHOBIMALT alone was not found to be effective as a surfactant for membrane extraction, when added to classical detergent micelles CHOBIMALT was observed to dramatically enhance the thermal stability of solubilized hKOR1.
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Affiliation(s)
- Stanley C Howell
- Department of Biochemistry, Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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21
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Batchelor R, Windle CJ, Buchoux S, Lorch M. Cholesterol and lipid phases influence the interactions between serotonin receptor agonists and lipid bilayers. J Biol Chem 2010; 285:41402-11. [PMID: 20961857 DOI: 10.1074/jbc.m110.155176] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Solid state NMR techniques have been used to investigate the effect that two serotonin receptor 1a agonists (quipazine and LY-165,163) have on the phase behavior of, and interactions within, cholesterol/phosphocholine lipid bilayers. The presence of agonist, and particularly LY-165,163, appears to widen the phase transitions, an effect that is much more pronounced in the presence of cholesterol. It was found that both agonists locate close to the cholesterol, and their interactions with the lipids are modulated by the lipid phases. As the membrane condenses into mixed liquid-ordered/disordered phases, quipazine is pushed up toward the surface of the bilayer, whereas LY-165,163 moves deeper into the lipid chain region. In light of our results, we discuss the role of lipid/drug interactions on drug efficacy.
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Affiliation(s)
- Rebecca Batchelor
- Department of Chemistry, University of Hull, Hull HU6 7RX, United Kingdom and
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22
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Structure and dynamics of cholesterol-containing polyunsaturated lipid membranes studied by neutron diffraction and NMR. J Membr Biol 2010; 239:63-71. [PMID: 21161517 PMCID: PMC3030944 DOI: 10.1007/s00232-010-9326-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 11/05/2010] [Indexed: 11/16/2022]
Abstract
A direct and quantitative analysis of the internal structure and dynamics of a polyunsaturated lipid bilayer composed of 1-stearoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine (18:0-22:6n3-PC) containing 29 mol% cholesterol was carried out by neutron diffraction, 2H-NMR and 13C-MAS NMR. Scattering length distribution functions of cholesterol segments as well as of the sn-1 and sn-2 hydrocarbon chains of 18:0-22:6n3-PC were obtained by conducting experiments with specifically deuterated cholesterol and lipids. Cholesterol orients parallel to the phospholipids, with the A-ring near the lipid glycerol and the terminal methyl groups 3 Å away from the bilayer center. Previously, we reported that the density of polyunsaturated docosahexaenoic acid (DHA, 22:6n3) chains was higher near the lipid–water interface. Addition of cholesterol partially redistributes DHA density from near the lipid–water interface to the center of the hydrocarbon region. Cholesterol raises chain-order parameters of both stearic acid and DHA chains. The fractional order increase for stearic acid methylene carbons C8–C18 is larger, reflecting the redistribution of DHA chain density toward the bilayer center. The correlation times of DHA chain isomerization are short and mostly unperturbed by the presence of cholesterol. The uneven distribution of saturated and polyunsaturated chain densities and the cholesterol-induced balancing of chain distributions may have important implications for the function and integrity of membrane receptors, such as rhodopsin.
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23
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Mannock DA, Lewis RN, McMullen TP, McElhaney RN. The effect of variations in phospholipid and sterol structure on the nature of lipid–sterol interactions in lipid bilayer model membranes. Chem Phys Lipids 2010; 163:403-48. [DOI: 10.1016/j.chemphyslip.2010.03.011] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 03/13/2010] [Accepted: 03/27/2010] [Indexed: 01/30/2023]
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24
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Rougier L, Milon A, Réat V, Jolibois F. Modelling the influence of hydrogen bond network on chemical shielding tensors description. GIAO-DFT study of WALP23 transmembrane α-helix as a test case. Phys Chem Chem Phys 2010; 12:6999-7008. [DOI: 10.1039/b923883b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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25
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del Rosal I, Gutmann T, Maron L, Jolibois F, Chaudret B, Walaszek B, Limbach HH, Poteau R, Buntkowsky G. DFT 2H quadrupolar coupling constants of ruthenium complexes: a good probe of the coordination of hydrides in conjuction with experiments. Phys Chem Chem Phys 2009; 11:5657-63. [PMID: 19842483 DOI: 10.1039/b822150b] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Transition metal (TM) hydrides are of great interest in chemistry because of their reactivity and their potential as catalysts for hydrogenation reactions. 2H solid-state NMR can be used in order to get information about the local environment of hydrogen atoms, and more particularly the coordination mode of hydrides in such complexes. In this work we will show that it is possible to establish at the level of density functional theory (DFT) a viable methodological strategy that allows the determination of 2H NMR parameters, namely the quadrupolar coupling constant (C(Q)) respectively the quadrupolar splitting (deltanuQ) and the asymmetry parameter (etaQ). The reliability of the method (B3PW91-DFT) and basis set effects have been first evaluated for simple organic compounds (benzene and fluorene). A good correlation between experimental and theoretical values is systematically obtained if the large basis set cc-pVTZ is used for the computations. 2H NMR properties of five mononuclear ruthenium complexes (namely Cp*RuD3(PPh3), Tp*RuD(THT)2, Tp*RuD(D2)(THT) and Tp*RuD(D2)2 and RuD2(D2)2(PCy3)2) which exhibit different ligands and hydrides involved in different coordination modes (terminal-H or eta2-H2), have been calculated and compared to previous experimental data. The results obtained are in excellent agreement with experiments. Although 2H NMR spectra are not always easy to analyze, assistance by quantum chemistry calculations allows unambiguous assignment of the signals of such spectra. As far as experiments can be achieved at very low temperatures in order to avoid dynamic effects, this hybrid theoretical/experimental tool may give useful insights in the context of the characterization of ruthenium surfaces or nanoparticles with solid-state NMR.
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Affiliation(s)
- Iker del Rosal
- Université de Toulouse; INSA, UPS; LPCNO, IRSAMC; 135 avenue de Rangueil, F-31077 Toulouse, France
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26
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Jayalakshmi K, Sonkar K, Behari A, Kapoor VK, Sinha N. Solid state (13)C NMR analysis of human gallstones from cancer and benign gall bladder diseases. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2009; 36:60-65. [PMID: 19577439 DOI: 10.1016/j.ssnmr.2009.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Accepted: 06/09/2009] [Indexed: 05/28/2023]
Abstract
Natural abundance (13)C cross polarized (CP) magic angle spinning (MAS) nuclear magnetic resonance (NMR) analysis of human gall bladder stones collected from patients suffering from malignant and benign gall bladder disease was carried out which revealed different polymorphs of cholesterol in these stones. All gall bladder stones in present study had cholesterol as their main constituent. (13)C CP-MAS NMR analysis revealed three forms of cholesterol molecules in these stones, which are anhydrous form, monohydrate crystalline with amorphous form and monohydrate crystalline form. Our study revealed that stones collected from patients associated with chronic cholecystitis (CC) disease have mostly different polymorph of cholesterol than stones collected from patients associated with gall bladder cancer (GBC). Such study will be helpful in understanding the mechanism of formation of gallstones which are associated with different gall bladder diseases. This is the first study by solid state NMR revealing different crystal polymorphism of cholesterol in human gallstones, extending the applicability of (13)C CP-MAS NMR technique for the routine study of gallstones.
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Affiliation(s)
- K Jayalakshmi
- Centre of Biomedical Magnetic Resonance, SGPGIMS Campus, Raibarelli Road, Lucknow 226014, India
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27
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Doherty T, Hong M. High-resolution solid-state NMR of anisotropically mobile molecules under very low-power (1)H decoupling and moderate magic-angle spinning. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2009; 199:225-232. [PMID: 19501003 PMCID: PMC3222301 DOI: 10.1016/j.jmr.2009.05.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 05/13/2009] [Accepted: 05/14/2009] [Indexed: 05/27/2023]
Abstract
We show that for observing high-resolution heteronuclear NMR spectra of anisotropically mobile systems with order parameters less than 0.25, moderate magic-angle spinning (MAS) rates of approximately 11kHz combined with (1)H decoupling at 1-2kHz are sufficient. Broadband decoupling at this low (1)H nutation frequency is achieved by composite pulse sequences such as WALTZ-16. We demonstrate this moderate MAS low-power decoupling technique on hydrated POPC lipid membranes, and show that 1kHz (1)H decoupling yields spectra with the same resolution and sensitivity as spectra measured under 50kHz (1)H decoupling when the same acquisition times (approximately 50ms) are used, but the low-power decoupled spectra give higher resolution and sensitivity when longer acquisition times (>150ms) are used, which are not possible with high-power decoupling. The limits of validity of this approach are explored for a range of spinning rates and molecular mobilities using more rigid membrane systems such as POPC/cholesterol mixed bilayers. Finally, we show (15)N and (13)C spectra of a uniaxially diffusing membrane peptide assembly, the influenza A M2 transmembrane domain, under 11kHz MAS and 2kHz (1)H decoupling. The peptide (15)N and (13)C intensities at low-power decoupling are 70-80% of the high-power decoupled intensities. Therefore, it is possible to study anisotropically mobile lipids and membrane peptides using liquid-state NMR equipment, relatively large rotors, and moderate MAS frequencies.
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Affiliation(s)
| | - Mei Hong
- Corresponding author: Mei Hong, Department of Chemistry, Iowa State University, Ames, IA 50010. Tel: 515-294-3521, Fax: 515-294-0105,
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28
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Alakoskela JM, Sabatini K, Jiang X, Laitala V, Covey DF, Kinnunen PKJ. Enantiospecific interactions between cholesterol and phospholipids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:830-836. [PMID: 18171092 DOI: 10.1021/la702909q] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The effects of cholesterol on various membrane proteins have received considerable attention. An important question regarding each of these effects is whether the cholesterol exerts its influence by binding directly to membrane proteins or by changing the properties of lipid bilayers. Recently it was suggested that a difference in the effects of natural cholesterol and its enantiomer, ent-cholesterol, would originate from direct binding of cholesterol to a target protein. This strategy rests on the fact that ent-cholesterol has appeared to have effects on lipid films similar to those of cholesterol, yet fluorescence microscopy studies of phospholipid monolayers have provided striking demonstrations of the enantiomer effects, showing opposite chirality of domain shapes for phospholipid enantiomer pairs. We observed the shapes of ordered domains in phospholipid monolayers containing either cholesterol or ent-cholesterol and found that the phospholipid chirality had a great effect on the domain chirality, whereas a minor (quantitative) effect of cholesterol chirality could be observed only in monolayers with racemic dipalmitoylphosphatidylcholine. The latter is likely to derive from cholesterol-cholesterol interactions. Accordingly, cholesterol chirality has only a modest effect that is highly likely to require the presence of solidlike domains and, accordingly, is unlikely to play a role in biological membranes.
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Affiliation(s)
- Juha-Matti Alakoskela
- Helsinki Biophysics and Biomembrane Group, Institute of Biomedicine/Biochemistry, P.O. Box 63, University of Helsinki, 00014 Helsinki, Finland.
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29
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del Rosal I, Maron L, Poteau R, Jolibois F. DFT calculations of 1H and 13C NMR chemical shifts in transition metal hydrides. Dalton Trans 2008:3959-70. [DOI: 10.1039/b802190b] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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30
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Vermeer LS, de Groot BL, Réat V, Milon A, Czaplicki J. Acyl chain order parameter profiles in phospholipid bilayers: computation from molecular dynamics simulations and comparison with 2H NMR experiments. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2007; 36:919-31. [PMID: 17598103 DOI: 10.1007/s00249-007-0192-9] [Citation(s) in RCA: 253] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Revised: 05/14/2007] [Accepted: 05/15/2007] [Indexed: 01/16/2023]
Abstract
Order parameters from deuterium NMR are often used to validate or calibrate molecular dynamics simulations. This paper gives a short overview of the literature in which experimental order parameters from (2)H NMR are compared to those calculated from MD simulations. The different ways in which order parameters from experiment are used to calibrate and validate simulations are reviewed. In the second part of this review, a case study of cholesterol in a DMPC bilayer is presented. It is concluded that the agreement between experimental data and simulation is favorable in the hydrophobic region of the membrane, for both the phospholipids and cholesterol. In the interfacial region the agreement is less satisfactory, probably because of the high polarity of this region which makes the correct computation of the electrostatics more complex.
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Affiliation(s)
- Louic S Vermeer
- IPBS (Institute of Pharmacology and Structural Biology), CNRS, UPS, Université de Toulouse, 118 route de Narbonne, 31077, Toulouse, France
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31
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Zhang J, Hadlock T, Gent A, Strichartz GR. Tetracaine-membrane interactions: effects of lipid composition and phase on drug partitioning, location, and ionization. Biophys J 2007; 92:3988-4001. [PMID: 17351014 PMCID: PMC1868989 DOI: 10.1529/biophysj.106.102434] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Accepted: 01/30/2007] [Indexed: 11/18/2022] Open
Abstract
Interactions of the local anesthetic tetracaine with unilamellar vesicles made of dimyristoyl or dipalmitoyl phosphatidylcholine (DMPC or DPPC), the latter without or with cholesterol, were examined by following changes in the drug's fluorescent properties. Tetracaine's location within the membrane (as indicated by the equivalent dielectric constant around the aromatic fluorophore), its membrane:buffer partition coefficients for protonated and base forms, and its apparent pK(a) when adsorbed to the membrane were determined by measuring, respectively, the saturating blue shifts of fluorescence emission at high lipid:tetracaine, the corresponding increases in fluorescence intensity at this lower wavelength with increasing lipid, and the dependence of fluorescence intensity of membrane-bound tetracaine (TTC) on solution pH. Results show that partition coefficients were greater for liquid-crystalline than solid-gel phase membranes, whether the phase was set by temperature or lipid composition, and were decreased by cholesterol; neutral TTC partitioned into membranes more strongly than the protonated species (TTCH(+)). Tetracaine's location in the membrane placed the drug's tertiary amine near the phosphate of the headgroup, its ester bond in the region of the lipids' ester bonds, and associated dipole field and the aromatic moiety near fatty acyl carbons 2-5; importantly, this location was unaffected by cholesterol and was the same for neutral and protonated tetracaine, showing that the dipole-dipole and hydrophobic interactions are the critical determinants of tetracaine's location. Tetracaine's effective pK(a) was reduced by 0.3-0.4 pH units from the solution pK(a) upon adsorption to these neutral bilayers, regardless of physical state or composition. We propose that the partitioning of tetracaine into solid-gel membranes is determined primarily by its steric accommodation between lipids, whereas in the liquid-crystalline membrane, in which the distance between lipid molecules is larger and steric hindrance is less important, hydrophobic and ionic interactions between tetracaine and lipid molecules predominate.
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Affiliation(s)
- Jingzhong Zhang
- Pain Research Center, Department of Anesthesiology, Perioperative, and Pain Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
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32
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Matsuoka S, Ikeuchi H, Umegawa Y, Matsumori N, Murata M. Membrane interaction of amphotericin B as single-length assembly examined by solid state NMR for uniformly 13C-enriched agent. Bioorg Med Chem 2006; 14:6608-14. [PMID: 16782343 DOI: 10.1016/j.bmc.2006.06.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Revised: 05/31/2006] [Accepted: 06/01/2006] [Indexed: 11/29/2022]
Abstract
The membrane interaction of amphotericin B (AmB), one of the most important anti-fungal drugs, was investigated by solid state NMR measurements of uniformly 13C-enriched AmB, which was prepared by the culture of the drug-producing microorganism in the presence of [u-13C6]glucose. All the 13C NMR signals of AmB upon binding to DLPC membrane were successfully assigned on the basis of the 13C-13C correlation spectrum. 13C-31P RDX (Rotational-Echo Double Resonance for X-clusters) experiments clearly revealed the REDOR dephasing effects for carbon atoms residing in the both terminal parts, whereas no dephasing was observed for the middle parts including polyolefinic C20-C33 and hydroxyl-bearing C8/C9 parts. These observations suggest that AmB binds to DLPC membrane with a high affinity to the phospholipid and spans the membrane with a single molecular length.
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Affiliation(s)
- Shigeru Matsuoka
- Department of Chemistry, Graduate School of Science, Osaka University, 1-16 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
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Holland GP, Alam TM. Multi-dimensional 1H-13C HETCOR and FSLG-HETCOR NMR study of sphingomyelin bilayers containing cholesterol in the gel and liquid crystalline states. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2006; 181:316-26. [PMID: 16798032 DOI: 10.1016/j.jmr.2006.05.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Revised: 05/23/2006] [Accepted: 05/31/2006] [Indexed: 05/10/2023]
Abstract
(13)C cross polarization magic angle spinning (CP-MAS) and (1)H MAS NMR spectra were collected on egg sphingomyelin (SM) bilayers containing cholesterol above and below the liquid crystalline phase transition temperature (T(m)). Two-dimensional (2D) dipolar heteronuclear correlation (HETCOR) spectra were obtained on SM bilayers in the liquid crystalline (L(alpha)) state for the first time and display improved resolution and chemical shift dispersion compared to the individual (1)H and (13)C spectra and significantly aid in spectral assignment. In the gel (L(beta)) state, the (1)H dimension suffers from line broadening due to the (1)H-(1)H homonuclear dipolar coupling that is not completely averaged by the combination of lipid mobility and MAS. This line broadening is significantly suppressed by implementing frequency switched Lee-Goldburg (FSLG) homonuclear (1)H decoupling during the evolution period. In the liquid crystalline (L(alpha)) phase, no improvement in line width is observed when FSLG is employed. All of the observed resonances are assignable to cholesterol and SM environments. This study demonstrates the ability to obtain 2D heteronuclear correlation experiments in the gel state for biomembranes, expands on previous SM assignments, and presents a comprehensive (1)H/(13)C NMR assignment of SM bilayers containing cholesterol. Comparisons are made to a previous report on cholesterol chemical shifts in dimyristoylphosphatidylcholine (DMPC) bilayers. A number of similarities and some differences are observed and discussed.
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Affiliation(s)
- Gregory P Holland
- Department of Electronic and Nanostructured Materials, Sandia National Laboratories, Albuquerque, NM 87185-0886, USA
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Alam TM, Holland GP. (1)H-(13)C INEPT MAS NMR correlation experiments with (1)H-(1)H mediated magnetization exchange to probe organization in lipid biomembranes. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2006; 180:210-21. [PMID: 16563820 DOI: 10.1016/j.jmr.2006.02.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Revised: 02/18/2006] [Accepted: 02/20/2006] [Indexed: 05/08/2023]
Abstract
Two-dimensional (1)H-(13)C INEPT MAS NMR experiments utilizing a (1)H-(1)H magnetization exchange mixing period are presented for characterization of lipid systems. The introduction of the exchange period allows for structural information to be obtained via (1)H-(1)H dipolar couplings but with (13)C chemical shift resolution. It is shown that utilizing a RFDR recoupling sequence with short mixing times in place of the more standard NOE cross-relaxation for magnetization exchange during the mixing period allowed for the identification and separation of close (1)H-(1)H dipolar contacts versus longer-range inter-molecular (1)H-(1)H dipolar cross-relaxation. These 2D INEPT experiments were used to address both intra- and inter-molecular contacts in lipid and lipid/cholesterol mixtures.
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Affiliation(s)
- T M Alam
- Department of Electronic and Nanostructured Materials, Sandia National Laboratories, Albuquerque, NM 87185, USA.
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Scheidt HA, Huster D, Gawrisch K. Diffusion of cholesterol and its precursors in lipid membranes studied by 1H pulsed field gradient magic angle spinning NMR. Biophys J 2005; 89:2504-12. [PMID: 16085761 PMCID: PMC1366749 DOI: 10.1529/biophysj.105.062018] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Cholesterol content is critical for membrane functional properties. We studied the influence of cholesterol and its precursors desmosterol and lanosterol on lateral diffusion of phospholipids and sterols by1H pulsed field gradients (PFG) magic angle spinning (MAS) NMR spectroscopy. The high resolution of resonances afforded by MAS NMR permitted simultaneous diffusion measurements on 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and sterols. The cholesterol diffusion mirrored the DPPC behavior, but rates were slightly higher at all cholesterol concentrations. DPPC and cholesterol diffusion rates decreased and became cholesterol concentration dependent with the onset of liquid-ordered phase formation. The activation energies of diffusion in the coexistence region of liquid-ordered/liquid-disordered phases are higher by about a factor of 2 compared to pure DPPC and to the pure liquid-ordered state formed at higher cholesterol concentrations. We assume that the higher activation energies are a reflection of lipid diffusion across domain boundaries. In lanosterol- and desmosterol-containing membranes, the DPPC and sterol diffusion coefficients are somewhat higher. Whereas the desmosterol rates are only slightly higher than those of DPPC, the lanosterol diffusion rates significantly exceed DPPC rates, indicating a weaker interaction between DPPC and lanosterol.
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Affiliation(s)
- Holger A Scheidt
- Junior Research Group, Solid-State NMR Studies of Membrane-Associated Proteins, Biotechnological-Biomedical Center and Institute of Medical Physics and Biophysics, University of Leipzig, D-04107 Leipzig, Germany
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Soubias O, Jolibois F, Massou S, Milon A, Réat V. Determination of the orientation and dynamics of ergosterol in model membranes using uniform 13C labeling and dynamically averaged 13C chemical shift anisotropies as experimental restraints. Biophys J 2005; 89:1120-31. [PMID: 15923221 PMCID: PMC1366597 DOI: 10.1529/biophysj.105.059857] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A new strategy was established to determine the average orientation and dynamics of ergosterol in dimyristoylphosphatidylcholine model membranes. It is based on the analysis of chemical shift anisotropies (CSAs) averaged by the molecular dynamics. Static (13)C CSA tensors were computed by quantum chemistry, using the gauge-including atomic-orbital approach within Hartree-Fock theory. Uniformly (13)C-labeled ergosterol was purified from Pichia pastoris cells grown on labeled methanol. After reconstitution into dimyristoylphosphatidylcholine lipids, the complete (1)H and (13)C assignment of ergosterol's resonances was performed using a combination of magic-angle spinning two-dimensional experiments. Dynamically averaged CSAs were determined by standard side-band intensity analysis for isolated (13)C resonances (C(3) and ethylenic carbons) and by off-magic-angle spinning experiments for other carbons. A set of 18 constraints was thus obtained, from which the sterol's molecular order parameter and average orientation could be precisely defined. The validity of using computed CSAs in this strategy was verified on cholesterol model systems. This new method allowed us to quantify ergosterol's dynamics at three molar ratios: 16 mol % (Ld phase), 30 mol % (Lo phase), and 23 mol % (mixed phases). Contrary to cholesterol, ergosterol's molecular diffusion axis makes an important angle (14 degrees) with the inertial axis of the rigid four-ring system.
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Affiliation(s)
- O Soubias
- Institut de Pharmacologie et de Biologie Structurale, UMR 5089, Toulouse, France.
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