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Pannuzzo M, Szała B, Raciti D, Raudino A, Ferrarini A. Helical Inclusions in Phospholipid Membranes: Lipid Adaptation and Chiral Order. J Phys Chem Lett 2019; 10:5629-5633. [PMID: 31487187 DOI: 10.1021/acs.jpclett.9b02252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The lipid bilayer is a flexible matrix that is able to adapt in response to the perturbation induced by inclusions, such as peptides and proteins. Here we use molecular dynamics simulations with a coarse-grained model to investigate the effect of a helical inclusion on a lipid bilayer in the liquid disordered phase. We show that the helical inclusion induces a collective tilt of acyl chains, with a small, yet unambiguous difference between a right- and a left-handed inclusion. This behavior is rationalized using the elastic continuum theory: The magnitude of the chiral (twist) deformation of the bilayer is determined by the interaction at the lipid/inclusion interface, and the decay length is controlled by the elastic properties of the bilayer. The lipid reorganization can thus be identified as a generic mechanism that, together with specific interactions, contributes to chiral recognition in phospholipid bilayers. An enhanced response is expected in highly ordered environments, such as rafts in biomembranes, with a potential impact on membrane-mediated interactions between inclusions.
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Affiliation(s)
- Martina Pannuzzo
- Laboratory of Nanotechnology for Precision Medicine , Fondazione Istituto Italiano di Tecnologia , via Morego, 30 , 16163 Genova , Italy
| | - Beata Szała
- Department of Chemical Sciences , University of Padova , via Marzolo 1 , 35131 Padova , Italy
- Faculty of Chemistry , Adam Mickiewicz University in Poznań , Umultowska 89b , 61-614 Poznań , Poland
| | - Domenica Raciti
- Department of Chemical Sciences , University of Catania , Viale A. Doria, 6 , 95125 Catania , Italy
| | - Antonio Raudino
- Department of Chemical Sciences , University of Catania , Viale A. Doria, 6 , 95125 Catania , Italy
| | - Alberta Ferrarini
- Department of Chemical Sciences , University of Padova , via Marzolo 1 , 35131 Padova , Italy
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Abstract
Cholesterol is a key steroidal, lipid biomolecule found abundantly in plasma membranes of eukaryotic cells. It is an important structural component of cellular membranes and regulates membrane fluidity and permeability. Cholesterol is also essential for normal functioning of key proteins including ion-channels, G protein-coupled receptors (GPCRs), membrane bound steroid receptors, and receptor kinases. It is thought that cholesterol exerts its actions via specific binding to chiral proteins and lipids as well as through non-specific physiochemical interactions. Distinguishing between the specific and the non-specific interactions can be difficult. Although much remains unclear, progress has been made in recent years by utilizing ent-cholesterol, the enantiomer of natural cholesterol (nat-cholesterol) as a probe. Ent-Cholesterol is the non-superimposable mirror image of nat-cholesterol and exhibits identical physiochemical properties as nat-cholesterol. Hence, if the biological effects of cholesterol result solely due to membrane effects, it is expected that there will be no difference between ent-cholesterol and nat-cholesterol. However, when direct binding with chiral proteins and lipids is involved, the enantiomer is expected to potentially elicit significantly different, measurable effects due to formation of diastereomeric complexes. In this chapter, we have reviewed the literature related to ent-cholesterol and its use as a probe for various biophysical and biological interactions of cholesterol.
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3
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Fantini J, Epand RM, Barrantes FJ. Cholesterol-Recognition Motifs in Membrane Proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1135:3-25. [PMID: 31098808 DOI: 10.1007/978-3-030-14265-0_1] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The impact of cholesterol on the structure and function of membrane proteins was recognized several decades ago, but the molecular mechanisms underlying these effects have remained elusive. There appear to be multiple mechanisms by which cholesterol interacts with proteins. A complete understanding of cholesterol-sensing motifs is still undergoing refinement. Initially, cholesterol was thought to exert only non-specific effects on membrane fluidity. It was later shown that this lipid could specifically interact with membrane proteins and affect both their structure and function. In this article, we have summarized and critically analyzed our evolving understanding of the affinity, specificity and stereoselectivity of the interactions of cholesterol with membrane proteins. We review the different computational approaches that are currently used to identify cholesterol binding sites in membrane proteins and the biochemical logic that governs each type of site, including CRAC, CARC, SSD and amphipathic helix motifs. There are physiological implications of these cholesterol-recognition motifs for G-protein coupled receptors (GPCR) and ion channels, in membrane trafficking and membrane fusion (SNARE) proteins. There are also pathological implications of cholesterol binding to proteins involved in neurological disorders (Alzheimer, Parkinson, Creutzfeldt-Jakob) and HIV fusion. In each case, our discussion is focused on the key molecular aspects of the cholesterol and amino acid motifs in membrane-embedded regions of membrane proteins that define the physiologically relevant crosstalk between the two. Our understanding of the factors that determine if these motifs are functional in cholesterol binding will allow us enhanced predictive capabilities.
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Affiliation(s)
- Jacques Fantini
- INSERM UMR_S 1072, Marseille, France. .,Aix-Marseille Université, Marseille, France.
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON, Canada
| | - Francisco J Barrantes
- Laboratory of Molecular Neurobiology, Biomedical Research Institute (BIOMED), UCA-CONICET, Buenos Aires, Argentina
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4
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Overduin M, Esmaili M. Memtein: The fundamental unit of membrane-protein structure and function. Chem Phys Lipids 2019; 218:73-84. [DOI: 10.1016/j.chemphyslip.2018.11.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 11/24/2018] [Accepted: 11/28/2018] [Indexed: 12/14/2022]
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Garvin MC, Austin A, Boyer K, Gefke M, Wright C, Pryor Y, Soble A, Whelan RJ. Attraction of Culex pipiens to House Sparrows Is Influenced by Host Age but Not Uropygial Gland Secretions. INSECTS 2018; 9:insects9040127. [PMID: 30257467 PMCID: PMC6315329 DOI: 10.3390/insects9040127] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 09/21/2018] [Accepted: 09/22/2018] [Indexed: 11/16/2022]
Abstract
Culex pipiens serves as the endemic vector of West Nile virus (WNV) in eastern North America, where house sparrows (HOSP, Passer domesticus) serve as a reservoir host. We tested the hypotheses that: (1) Attraction of Cx. pipiens to HOSP is influenced by bird age and (2) that age-specific variation in chemical profiles of bird uropygial gland secretions informs this choice. We conducted mosquito choice trials in an olfactometer and found that Cx. pipiens were more often attracted to adult sparrows over nestlings, however, they demonstrated no preference for adults over fledglings. Using gas chromatography-mass spectrometry we observed age-specific differences in the semi-volatile chemical profiles of house sparrow uropygial gland secretions. Contrary to our hypothesis, we found no significant difference in mosquito feeding preference between the secretions of adults and those of either nestlings or fledglings. We suggest that other chemical cues influence the feeding preference of Cx. pipiens, either independently of uropygial gland secretions, or synergistically with them.
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Affiliation(s)
- Mary C Garvin
- Department of Biology, Oberlin College, Oberlin, OH 44074, USA.
| | - Amy Austin
- Department of Biology, Oberlin College, Oberlin, OH 44074, USA.
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin OH 44074, USA.
| | - Kevin Boyer
- Department of Biology, Oberlin College, Oberlin, OH 44074, USA.
| | - Madeleine Gefke
- Department of Biology, Oberlin College, Oberlin, OH 44074, USA.
| | | | - Yemko Pryor
- Department of Biology, Oberlin College, Oberlin, OH 44074, USA.
| | - Anah Soble
- Department of Biology, Oberlin College, Oberlin, OH 44074, USA.
| | - Rebecca J Whelan
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin OH 44074, USA.
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA.
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6
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Garvin MC, Austin AL, Stracker NH, Slowinski SP, Rutter JE, Butler M, Michel M, Whelan RJ. Attraction of Culex pipiens to uropygial gland secretions does not explain feeding preference for American robins. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2018; 43:110-116. [PMID: 29757510 DOI: 10.1111/jvec.12290] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 01/21/2018] [Indexed: 06/08/2023]
Abstract
Culex pipiens, the endemic mosquito vector of West Nile virus in eastern North America, is responsible for maintenance of the virus in avian reservoir hosts, the most important of which appears to be the American robin. One reason for the greater involvement of robins is believed to be the feeding preference of Cx. pipiens, however, the basis of this preference is not understood. We tested the hypothesis that the species-specific chemical profile of avian uropygial gland secretions are used by Cx. pipiens as cues to locate birds and, therefore, may contribute to the observed feeding preferences. We used gas chromatography-mass spectrometry to identify the semi-volatile components of the uropygial gland secretions of American robins and two other common reservoir host species, the house sparrow and European starling. We found that the chemical composition of the robin secretions was different from those of the sparrows and starlings. Through behavioral choice trials conducted in a dual-port olfactometer, we also found that Cx. pipiens did not prefer the secretions of robins over the other two species. Surprisingly, however, we found that Cx pipiens were more often attracted to live starlings over robins and to the secretions of starlings over those of robins.
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Affiliation(s)
- Mary C Garvin
- Department of Biology, Oberlin College, Oberlin OH 44074, U.S.A
| | - Amy L Austin
- Department of Biology, Oberlin College, Oberlin OH 44074, U.S.A
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin OH 44074, U.S.A
| | | | | | - Jordan E Rutter
- Department of Biology, Oberlin College, Oberlin OH 44074, U.S.A
| | - Maxwell Butler
- Department of Biology, Oberlin College, Oberlin OH 44074, U.S.A
| | - Megan Michel
- Department of Biology, Oberlin College, Oberlin OH 44074, U.S.A
| | - Rebecca J Whelan
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin OH 44074, U.S.A
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Suga K, Tauchi A, Ishigami T, Okamoto Y, Umakoshi H. Preferential Adsorption of l-Histidine onto DOPC/Sphingomyelin/3β-[N-(N',N'-dimethylaminoethane)carbamoyl]cholesterol Liposomes in the Presence of Chiral Organic Acids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:3831-3838. [PMID: 28272888 DOI: 10.1021/acs.langmuir.6b03264] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We investigated the effect of organic acids such as mandelic acid (MA) and tartaric acid (TA) on the adsorption behavior of both histidine (His) and propranolol (PPL) onto liposomes. A cationic and heterogeneous liposome prepared using 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/sphingomyelin (SM)/3β-[N-(N',N'-dimethylaminoethane)carbamoyl]cholesterol (DC-Ch) in a ratio of (4/3/3) showed the highest adsorption efficiency of MA and TA independent of chirality, while neutral liposome DOPC/SM/cholesterol = (4/3/3) showed low efficiency. As expected, electrostatic interactions were dominant in MA or TA adsorption onto DOPC/SM/DC-Ch = (4/3/3) liposomes, suggesting that organic acids had adsorbed onto SM/DC-Ch-enriched domains. The adsorption behaviors of organic acids onto DOPC/SM/DC-Ch = (4/3/3) were governed by Langmuir adsorption isotherms. For adsorption, the membrane polarities slightly decreased (i.e., membrane surface was hydrophilic), but no alterations in membrane fluidity were observed. In the presence of organic acids that had been preincubated with DOPC/SM/DC-Ch = (4/3/3), the adsorption of l- and d-His onto those liposomes was examined. Preferential l-His adsorption was dramatically prevented only in the presence of l-MA, suggesting that the adsorption sites for l-His and l-MA on DOPC/SM/DC-Ch = (4/3/3) liposomes are competitive, while those for l-His and d-MA, l-TA, and d-TA are isolated.
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Affiliation(s)
- Keishi Suga
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University , 1-3 Machikaneyamacho, Toyonaka, Osaka 560-8531, Japan
| | - Atsushi Tauchi
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University , 1-3 Machikaneyamacho, Toyonaka, Osaka 560-8531, Japan
| | - Takaaki Ishigami
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University , 1-3 Machikaneyamacho, Toyonaka, Osaka 560-8531, Japan
| | - Yukihiro Okamoto
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University , 1-3 Machikaneyamacho, Toyonaka, Osaka 560-8531, Japan
| | - Hiroshi Umakoshi
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University , 1-3 Machikaneyamacho, Toyonaka, Osaka 560-8531, Japan
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8
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Fürst O, Nichols CG, Lamoureux G, D'Avanzo N. Identification of a cholesterol-binding pocket in inward rectifier K(+) (Kir) channels. Biophys J 2016; 107:2786-2796. [PMID: 25517146 DOI: 10.1016/j.bpj.2014.10.066] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 09/24/2014] [Accepted: 10/08/2014] [Indexed: 11/28/2022] Open
Abstract
Cholesterol is the major sterol component of all mammalian plasma membranes. Recent studies have shown that cholesterol inhibits both bacterial (KirBac1.1 and KirBac3.1) and eukaryotic (Kir2.1) inward rectifier K(+) (Kir) channels. Lipid-sterol interactions are not enantioselective, and the enantiomer of cholesterol (ent-cholesterol) does not inhibit Kir channel activity, suggesting that inhibition results from direct enantiospecific binding to the channel, and not indirect effects of changes to the bilayer. Furthermore, conservation of the effect of cholesterol among prokaryotic and eukaryotic Kir channels suggests an evolutionary conserved cholesterol-binding pocket, which we aimed to identify. Computational experiments were performed by docking cholesterol to the atomic structures of Kir2.2 (PDB: 3SPI) and KirBac1.1 (PDB: 2WLL) using Autodock 4.2. Poses were assessed to ensure biologically relevant orientation and then clustered according to location and orientation. The stability of cholesterol in each of these poses was then confirmed by molecular dynamics simulations. Finally, mutation of key residues (S95H and I171L) in this putative binding pocket found within the transmembrane domain of Kir2.1 channels were shown to lead to a loss of inhibition by cholesterol. Together, these data provide support for this location as a biologically relevant pocket.
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Affiliation(s)
- Oliver Fürst
- Département de Physiologie Moléculaire et Intégrative and Groupe d'Étude des Protéines Membranaires (GÉPROM), Université de Montréal, Montreal, Quebec, Canada
| | - Colin G Nichols
- Department of Cell Biology and Physiology and Center for Investigation of Membrane Excitabiltiy Diseases, Washington University School of Medicine, St. Louis, Missouri
| | - Guillaume Lamoureux
- Department of Chemistry and Biochemistry, Centre for Research in Molecular Modeling (CERMM), Groupe d'Étude des Protéines Membranaires (GÉPROM), Concordia University, Montreal, Quebec, Canada
| | - Nazzareno D'Avanzo
- Département de Physiologie Moléculaire et Intégrative and Groupe d'Étude des Protéines Membranaires (GÉPROM), Université de Montréal, Montreal, Quebec, Canada.
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9
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Kepczynski M, Róg T. Functionalized lipids and surfactants for specific applications. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2362-2379. [PMID: 26946243 DOI: 10.1016/j.bbamem.2016.02.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 02/23/2016] [Accepted: 02/25/2016] [Indexed: 12/17/2022]
Abstract
Synthetic lipids and surfactants that do not exist in biological systems have been used for the last few decades in both basic and applied science. The most notable applications for synthetic lipids and surfactants are drug delivery, gene transfection, as reporting molecules, and as support for structural lipid biology. In this review, we describe the potential of the synergistic combination of computational and experimental methodologies to study the behavior of synthetic lipids and surfactants embedded in lipid membranes and liposomes. We focused on select cases in which molecular dynamics simulations were used to complement experimental studies aiming to understand the structure and properties of new compounds at the atomistic level. We also describe cases in which molecular dynamics simulations were used to design new synthetic lipids and surfactants, as well as emerging fields for the application of these compounds. This article is part of a Special Issue entitled: Biosimulations edited by Ilpo Vattulainen and Tomasz Róg.
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Affiliation(s)
- Mariusz Kepczynski
- Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
| | - Tomasz Róg
- Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101, Tampere, Finland; Department of Physics, Helsinki University, P.O. Box 64, FI 00014 Helsinki, Finland.
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10
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D'Avanzo N, Hyrc K, Enkvetchakul D, Covey DF, Nichols CG. Enantioselective protein-sterol interactions mediate regulation of both prokaryotic and eukaryotic inward rectifier K+ channels by cholesterol. PLoS One 2011; 6:e19393. [PMID: 21559361 PMCID: PMC3084843 DOI: 10.1371/journal.pone.0019393] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 03/29/2011] [Indexed: 02/06/2023] Open
Abstract
Cholesterol is the major sterol component of all mammalian cell plasma membranes and plays a critical role in cell function and growth. Previous studies have shown that cholesterol inhibits inward rectifier K+ (Kir) channels, but have not distinguished whether this is due directly to protein-sterol interactions or indirectly to changes in the physical properties of the lipid bilayer. Using purified bacterial and eukaryotic Kir channels reconstituted into liposomes of controlled lipid composition, we demonstrate by 86Rb+ influx assays that bacterial Kir channels (KirBac1.1 and KirBac3.1) and human Kir2.1 are all inhibited by cholesterol, most likely by locking the channels into prolonged closed states, whereas the enantiomer, ent-cholesterol, does not inhibit these channels. These data indicate that cholesterol regulates Kir channels through direct protein-sterol interactions likely taking advantage of an evolutionarily conserved binding pocket.
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Affiliation(s)
- Nazzareno D'Avanzo
- Department of Cell Biology and Physiology, and Center for Investigation of Membrane Excitability Diseases, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Krzysztof Hyrc
- Department of Cell Biology and Physiology, and Center for Investigation of Membrane Excitability Diseases, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Decha Enkvetchakul
- Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri, United States of America
| | - Douglas F. Covey
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Colin G. Nichols
- Department of Cell Biology and Physiology, and Center for Investigation of Membrane Excitability Diseases, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
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11
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Tsuchiya H, Ueno T, Mizogami M. Stereostructure-based differences in the interactions of cardiotoxic local anesthetics with cholesterol-containing biomimetic membranes. Bioorg Med Chem 2011; 19:3410-5. [PMID: 21550810 DOI: 10.1016/j.bmc.2011.04.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Revised: 04/12/2011] [Accepted: 04/13/2011] [Indexed: 01/09/2023]
Abstract
Amide-type pipecoloxylidide local anesthetics, bupivacaine, and ropivacaine, show cardiotoxic effects with the potency depending on stereostructures. Cardiotoxic drugs not only bind to cardiomyocyte membrane channels to block them but also modify the physicochemical property of membrane lipid bilayers in which channels are embedded. The opposite configurations allow enantiomers to be discriminated by their enantiospecific interactions with another chiral molecule in membranes. We compared the interactions of local anesthetic stereoisomers with biomimetic membranes consisting of chiral lipid components, the differences of which might be indicative of the drug design for reducing cardiotoxicity. Fluorescent probe-labeled biomimetic membranes were prepared with cardiolipin and cholesterol of varying compositions and different phospholipids. Local anesthetics were reacted with the membrane preparations at a cardiotoxically relevant concentration of 200 μM. The potencies to interact with biomimetic membranes and change their fluidity were compared by measuring fluorescence polarization. All local anesthetics acted on lipid bilayers to increase membrane fluidity. Chiral cardiolipin was ineffective in discriminating S(-)-enantiomers from their antipodes. On the other hand, cholesterol produced the enantiospecific membrane interactions of bupivacaine and ropivacaine with increasing its composition in membranes. In 40 mol% and more cholesterol-containing membranes, the membrane-interacting potency was S(-)-bupivacaine<racemic bupivacaine<R(+)-bupivacaine, and S(-)-ropivacaine<R(+)-ropivacaine. Ropivacaine (S(-)-enantiomer), levobupivacaine (S(-)-enantiomeric), and bupivacaine (racemic) interacted with biomimetic membranes in increasing order of intensity. The rank order of membrane interactivity agreed with that of known cardiotoxicity. The stereoselective membrane interactions determined by cholesterol with higher chirality appears to be associated with the stereoselective cardiotoxic effects of local anesthetics. The stereostructure and membrane interactivity relationship supports the clinical use and development of S(-)-enantiomers to decrease the adverse effects of pipecoloxylidide local anesthetics on the cardiovascular system.
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Affiliation(s)
- Hironori Tsuchiya
- Department of Dental Basic Education, Asahi University School of Dentistry, Mizuho, Gifu 501-0296, Japan.
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12
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Covey DF. ent-Steroids: novel tools for studies of signaling pathways. Steroids 2009; 74:577-85. [PMID: 19103212 PMCID: PMC2668732 DOI: 10.1016/j.steroids.2008.11.019] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 11/21/2008] [Accepted: 11/24/2008] [Indexed: 12/24/2022]
Abstract
Membrane receptors are often modulated by steroids and it is necessary to distinguish the effects of steroids at these receptors from effects occurring at nuclear receptors. Additionally, it may also be mechanistically important to distinguish between direct effects caused by binding of steroids to membrane receptors and indirect effects on membrane receptor function caused by steroid perturbation of the membrane containing the receptor. In this regard, ent-steroids, the mirror images of naturally occurring steroids, are novel tools for distinguishing between these various actions of steroids. The review provides a background for understanding the different actions that can be expected of steroids and ent-steroids in biological systems, references for the preparation of ent-steroids, a short discussion about relevant forms of stereoisomerism and the requirements that need to be fulfilled for the interaction between two molecules to be enantioselective. The review then summarizes results of biophysical, biochemical and pharmacological studies published since 1992 in which ent-steroids have been used to investigate the actions of steroids in membranes and/or receptor-mediated signaling pathways.
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Affiliation(s)
- Douglas F Covey
- Department of Developmental Biology, Campus Box 8103, Washington Univ. in St. Louis, School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, United States.
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Abstract
ent-Cholesterol was synthesized in 16 steps from commercially available (S)-citronellol. The overall yield for the synthesis was 2.0%. This route is amenable to gram-scale preparation of ent-cholesterol. Isotopic incorporation near the end of the synthesis was achieved using labeled methyl iodide. This synthesis is the most practical to date and will make ent-cholesterol more readily available to use as a probe of the function and metabolism of cholesterol.
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Affiliation(s)
- Jitendra D. Belani
- Department of Chemistry, 1102 Natural Sciences II, University of California, Irvine, Irvine, California 92697
| | - Scott D. Rychnovsky
- Department of Chemistry, 1102 Natural Sciences II, University of California, Irvine, Irvine, California 92697
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14
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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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15
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Chiral recognition of dipeptides in bio-membrane models: the role of amphiphile hydrophobic chains. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.tetasy.2007.11.035] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Tverdislov VA, Yakovenko LV, Zhavoronkov AA. Chirality as a problem of biochemical physics. RUSS J GEN CHEM+ 2007. [DOI: 10.1134/s1070363207110291] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Alzalamira A, Ceccacci F, Monti D, Mortera SL, Mancini G, Sorrenti A, Venanzi M, Villani C. Discrimination of the enantiomers of biphenylic derivatives in micellar aggregates formed by chiral amidic surfactants. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.tetasy.2007.07.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Cruciani O, Borocci S, Lamanna R, Mancini G, Segre AL. Chiral recognition of dipeptides in phosphatidylcholine aggregates. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.tetasy.2006.10.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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