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Weakly HMJ, Wilson KJ, Goetz GJ, Pruitt EL, Li A, Xu L, Keller SL. Several common methods of making vesicles (except an emulsion method) capture intended lipid ratios. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.21.581444. [PMID: 38948736 PMCID: PMC11212916 DOI: 10.1101/2024.02.21.581444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Researchers choose different methods of making giant unilamellar vesicles in order to satisfy different constraints of their experimental designs. A challenge of using a variety of methods is that each may produce vesicles of different lipid compositions, even if all vesicles are made from a common stock mixture. Here, we use mass spectrometry to investigate ratios of lipids in vesicles made by five common methods: electroformation on indium tin oxide slides, electroformation on platinum wires, gentle hydration, emulsion transfer, and extrusion. We made vesicles from either 5-component or binary mixtures of lipids chosen to span a wide range of physical properties: di(18:1)PC, di(16:0)PC, di(18:1)PG, di(12:0)PE, and cholesterol. For a mixture of all five of these lipids, ITO electroformation, Pt electroformation, gentle hydration, and extrusion methods result in only minor shifts (≤ 5 mol%) in lipid ratios of vesicles relative to a common stock solution. In contrast, emulsion transfer results in ∼80% less cholesterol than expected from the stock solution, which is counterbalanced by a surprising overabundance of saturated PC-lipid relative to all other phospholipids. Experiments using binary mixtures of some of the lipids largely support results from the 5-component mixture. Exact values of lipid ratios variations likely depend on the details of each method, so a broader conclusion is that experiments that increment lipid ratios in small steps will be highly sensitive to the method of lipid formation and to sample-to-sample variations, which are low (roughly ±2 mol% in the 5-component mixture and either scale proportionally with increasing mole fraction or remain low). Experiments that increment lipid ratios in larger steps or that seek to explain general trends or new phenomena will be less sensitive to the method used. SIGNIFICANCE STATEMENT Small changes to the amounts and types of lipids in membranes can drastically affect the membrane's behavior. Unfortunately, it is unknown whether (or to what extent) different methods of making vesicles alter the ratios of lipids in membranes, even when identical stock solutions are used. This presents challenges for researchers when comparing data with colleagues who use different methods. Here, we measure ratios of lipid types in vesicle membranes produced by five methods. We assess each method's reproducibility and compare resulting vesicle compositions across methods. In doing so, we provide a quantitative basis that the scientific community can use to estimate whether differences between their results can be simply attributed to differences between methods or to sample-to-sample variations.
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O'Brien RA, Hillesheim PC, Soltani M, Badilla-Nunez KJ, Siu B, Musozoda M, West KN, Davis JH, Mirjafari A. Cyclopropane as an Unsaturation "Effect Isostere": Lowering the Melting Points in Lipid-like Ionic Liquids. J Phys Chem B 2023; 127:1429-1442. [PMID: 36745872 DOI: 10.1021/acs.jpcb.2c07872] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The replacement of unsaturation with a cyclopropane motif as a (bio)isostere is a widespread strategy in bacteria to tune the fluidity of lipid bilayers and protect membranes when exposed to adverse environmental conditions, e.g., high temperature, low pH, etc. Inspired by this phenomenon, we herein address the relative effect of the cyclopropanation, both cis and trans configurations, on melting points, packing efficiency, and order of a series of lipid-like ionic liquids via a combination of thermophysical analysis, X-ray crystallography, and computational modeling. The data indicate there is considerable structural latitude possible when designing highly lipophilic ionic liquids that exhibit low melting points. While cyclopropanation of the lipid-like ionic liquids provides more resistance to aerobic degradation than their olefin analogs, the impact on the melting point decrease is not as pronounced. Our results demonstrate that incorporating one or more cyclopropyl moieties in long aliphatic chains of imidazolium-based ionic liquids is highly effective in lowering the melting points of such materials relative to their counterparts bearing linear, saturated, or thioether side chains. It is shown that the cyclopropane moiety effectively disrupts packing, favoring formation of gauche conformer in the side chains, resulting in enhancement of fluidity. This was irrespective of the configuration of the methylene bridge, although marked differences in the effect of cis- and trans-monocyclopropanated ILs on the melting points were observed.
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Affiliation(s)
- Richard A O'Brien
- Department of Chemistry, The University of South Alabama, Mobile, Alabama 36688, United States
| | - Patrick C Hillesheim
- Department of Chemistry and Physics, Ave Maria University, Ave Maria, Florida 34142, United States
| | - Mohammad Soltani
- Department of Chemistry, The University of South Alabama, Mobile, Alabama 36688, United States
| | - Kelly J Badilla-Nunez
- Department of Chemical and Biomolecular Engineering, The University of South Alabama, Mobile, Alabama 36688, United States
| | - Ben Siu
- Department of Chemical and Biomolecular Engineering, The University of South Alabama, Mobile, Alabama 36688, United States
| | - Muhammadiqboli Musozoda
- Department of Chemistry, State University of New York at Oswego, Oswego, New York 13126, United States
| | - Kevin N West
- Department of Chemical and Biomolecular Engineering, The University of South Alabama, Mobile, Alabama 36688, United States
| | - James H Davis
- Department of Chemistry, The University of South Alabama, Mobile, Alabama 36688, United States
| | - Arsalan Mirjafari
- Department of Chemistry, State University of New York at Oswego, Oswego, New York 13126, United States
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3
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Daear W, Sule K, Lai P, Prenner EJ. Biophysical analysis of gelatin and PLGA nanoparticle interactions with complex biomimetic lung surfactant models. RSC Adv 2022; 12:27918-27932. [PMID: 36320247 PMCID: PMC9523518 DOI: 10.1039/d2ra02859j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 09/22/2022] [Indexed: 11/21/2022] Open
Abstract
Biocompatible materials are increasingly used for pulmonary drug delivery, and it is essential to understand their potential impact on the respiratory system, notably their effect on lung surfactant, a monolayer of lipids and proteins, responsible for preventing alveolar collapse during breathing cycles. We have developed a complex mimic of lung surfactant composed of eight lipids mixed in ratios reported for native lung surfactant. A synthetic peptide based on surfactant protein B was added to better mimic the biological system. This model was used to evaluate the impact of biocompatible gelatin and poly(lactic-co-glycolic acid) nanoparticles. Surface pressure–area isotherms were used to assess lipid packing, film compressibility and stability, whereas the lateral organization was visualized by Brewster angle microscopy. Nanoparticles increased film fluidity and altered the monolayer collapse pressure. Bright protruding clusters formed in their presence indicate a significant impact on the lateral organization of the surfactant film. Altogether, this work indicates that biocompatible materials considered to be safe for drug delivery still need to be assessed for their potential detrimental impact before use in therapeutic applications Biodegradable nanoparticles drastically alters lateral organization of lung surfactant lipid- peptide model system.![]()
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Affiliation(s)
- W. Daear
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - K. Sule
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - P. Lai
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - E. J. Prenner
- Department of Biological Sciences, University of Calgary, Calgary, AB, T2N 1N4, Canada
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4
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Blitzblau HG, Consiglio AL, Teixeira P, Crabtree DV, Chen S, Konzock O, Chifamba G, Su A, Kamineni A, MacEwen K, Hamilton M, Tsakraklides V, Nielsen J, Siewers V, Shaw AJ. Production of 10-methyl branched fatty acids in yeast. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:12. [PMID: 33413611 PMCID: PMC7791843 DOI: 10.1186/s13068-020-01863-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 12/17/2020] [Indexed: 06/12/2023]
Abstract
BACKGROUND Despite the environmental value of biobased lubricants, they account for less than 2% of global lubricant use due to poor thermo-oxidative stability arising from the presence of unsaturated double bonds. Methyl branched fatty acids (BFAs), particularly those with branching near the acyl-chain mid-point, are a high-performance alternative to existing vegetable oils because of their low melting temperature and full saturation. RESULTS We cloned and characterized two pathways to produce 10-methyl BFAs isolated from actinomycetes and γ-proteobacteria. In the two-step bfa pathway of actinomycetes, BfaB methylates Δ9 unsaturated fatty acids to form 10-methylene BFAs, and subsequently, BfaA reduces the double bond to produce a fully saturated 10-methyl branched fatty acid. A BfaA-B fusion enzyme increased the conversion efficiency of 10-methyl BFAs. The ten-methyl palmitate production (tmp) pathway of γ-proteobacteria produces a 10-methylene intermediate, but the TmpA putative reductase was not active in E. coli or yeast. Comparison of BfaB and TmpB activities revealed a range of substrate specificities from C14-C20 fatty acids unsaturated at the Δ9, Δ10 or Δ11 position. We demonstrated efficient production of 10-methylene and 10-methyl BFAs in S. cerevisiae by secretion of free fatty acids and in Y. lipolytica as triacylglycerides, which accumulated to levels more than 35% of total cellular fatty acids. CONCLUSIONS We report here the characterization of a set of enzymes that can produce position-specific methylene and methyl branched fatty acids. Yeast expression of bfa enzymes can provide a platform for the large-scale production of branched fatty acids suitable for industrial and consumer applications.
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Affiliation(s)
- Hannah G Blitzblau
- Novogy, Inc., 85 Bolton Street, Cambridge, MA, 02140, USA.
- Ginkgo BioWorks, 27 Drydock Ave., Boston, MA, 02210, USA.
| | - Andrew L Consiglio
- Novogy, Inc., 85 Bolton Street, Cambridge, MA, 02140, USA
- Ginkgo BioWorks, 27 Drydock Ave., Boston, MA, 02210, USA
| | - Paulo Teixeira
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden
| | | | - Shuyan Chen
- Novogy, Inc., 85 Bolton Street, Cambridge, MA, 02140, USA
- Ginkgo BioWorks, 27 Drydock Ave., Boston, MA, 02210, USA
| | - Oliver Konzock
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden
| | - Gamuchirai Chifamba
- Novogy, Inc., 85 Bolton Street, Cambridge, MA, 02140, USA
- Ginkgo BioWorks, 27 Drydock Ave., Boston, MA, 02210, USA
| | - Austin Su
- Novogy, Inc., 85 Bolton Street, Cambridge, MA, 02140, USA
| | - Annapurna Kamineni
- Novogy, Inc., 85 Bolton Street, Cambridge, MA, 02140, USA
- Ginkgo BioWorks, 27 Drydock Ave., Boston, MA, 02210, USA
| | - Kyle MacEwen
- Novogy, Inc., 85 Bolton Street, Cambridge, MA, 02140, USA
- Ginkgo BioWorks, 27 Drydock Ave., Boston, MA, 02210, USA
| | - Maureen Hamilton
- Novogy, Inc., 85 Bolton Street, Cambridge, MA, 02140, USA
- Ginkgo BioWorks, 27 Drydock Ave., Boston, MA, 02210, USA
| | - Vasiliki Tsakraklides
- Novogy, Inc., 85 Bolton Street, Cambridge, MA, 02140, USA
- Ginkgo BioWorks, 27 Drydock Ave., Boston, MA, 02210, USA
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden
- BioInnovation Institute, Ole Maaløes Vej 3, 2200, Copenhagen N, Denmark
| | - Verena Siewers
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden
| | - A Joe Shaw
- Novogy, Inc., 85 Bolton Street, Cambridge, MA, 02140, USA
- Manus Biosynthesis, 1030 Massachusetts Ave. #300, Cambridge, MA, 02138, USA
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5
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Parisi LR, Sowlati-Hashjin S, Berhane IA, Galster SL, Carter KA, Lovell JF, Chemler SR, Karttunen M, Atilla-Gokcumen GE. Membrane Disruption by Very Long Chain Fatty Acids during Necroptosis. ACS Chem Biol 2019; 14:2286-2294. [PMID: 31490656 DOI: 10.1021/acschembio.9b00616] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Necroptosis is a form of regulated cell death which results in loss of plasma membrane integrity, release of intracellular contents, and an associated inflammatory response. We previously found that saturated very long chain fatty acids (VLCFAs), which contain ≥20 carbons, accumulate during necroptosis. Here, we show that genetic knockdown of Fatty Acid (FA) Elongase 7 (ELOVL7) reduces accumulation of specific very long chain FAs during necroptosis, resulting in reduced necroptotic cell death and membrane permeabilization. Conversely, increasing the expression of ELOVL7 increases very long chain fatty acids and membrane permeabilization. In vitro, introduction of the VLCFA C24 FA disrupts bilayer integrity in liposomes to a greater extent than a conventional C16 FA. To investigate the microscopic origin of these observations, atomistic Molecular Dynamics (MD) simulations were performed. MD simulations suggest that fatty acids cause clear differences in bilayers based on length and that it is the interdigitation of C24 FA between the individual leaflets that results in disorder in the region and, consequently, membrane disruption. We synthesized clickable VLCFA analogs and observed that many proteins were acylated by VLCFAs during necroptosis. Taken together, these results confirm the active role of VLCFAs during necroptosis and point to multiple potential mechanisms of membrane disruption including direct permeabilization via bilayer disruption and permeabilization by targeting of proteins to cellular membranes by fatty acylation.
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Affiliation(s)
- Laura R. Parisi
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Shahin Sowlati-Hashjin
- Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada
- The Centre of Advanced Materials and Biomaterials Research, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada
| | - Ilyas A. Berhane
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Samuel L. Galster
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Kevin A. Carter
- Department of Biomedical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Jonathan F. Lovell
- Department of Biomedical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Sherry R. Chemler
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Mikko Karttunen
- Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada
- Department of Applied Mathematics, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada
- The Centre of Advanced Materials and Biomaterials Research, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada
| | - G. Ekin Atilla-Gokcumen
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
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6
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Borcik CG, Versteeg DB, Wylie BJ. An Inward-Rectifier Potassium Channel Coordinates the Properties of Biologically Derived Membranes. Biophys J 2019; 116:1701-1718. [PMID: 31010661 DOI: 10.1016/j.bpj.2019.03.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 03/20/2019] [Accepted: 03/25/2019] [Indexed: 12/13/2022] Open
Abstract
KirBac1.1 is a prokaryotic inward-rectifier K+ channel from Burkholderia pseudomallei. It shares the common inward-rectifier K+ channel fold with eukaryotic channels, including conserved lipid-binding pockets. Here, we show that KirBac1.1 changes the phase properties and dynamics of the surrounding bilayer. KirBac1.1 was reconstituted into vesicles composed of 13C-enriched biological lipids. Two-dimensional liquid-state and solid-state NMR experiments were used to assign lipid 1H and 13C chemical shifts as a function of lipid identity and conformational degrees of freedom. A solid-state NMR temperature series reveals that KirBac1.1 lowers the primary thermotropic phase transition of Escherichia coli lipid membranes while introducing both fluidity and internal lipid order into the fluid phases. In B. thailandensis liposomes, the bacteriohopanetetrol hopanoid, and potentially ornithine lipids, introduce a similar primary lipid-phase transition and liquid-ordered properties. Adding KirBac1.1 to B. thailandensis lipids increases B. thailandensis lipid fluidity while preserving internal lipid order. This synergistic effect of KirBac1.1 in bacteriohopanetetrol-rich membranes has implications for bilayer dynamic structure. If membrane proteins can anneal lipid translational degrees of freedom while preserving internal order, it could offer an explanation to the nature of liquid-ordered protein-lipid organization in vivo.
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Affiliation(s)
- Collin G Borcik
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas
| | - Derek B Versteeg
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas
| | - Benjamin J Wylie
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas.
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7
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Zheng Y, Liu X, Samoshina NM, Samoshin VV, Franz AH, Guo X. Fliposomes: trans-2-aminocyclohexanol-based amphiphiles as pH-sensitive conformational switches of liposome membrane - a structure-activity relationship study. Chem Phys Lipids 2017; 210:129-141. [PMID: 29111431 DOI: 10.1016/j.chemphyslip.2017.10.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 10/10/2017] [Accepted: 10/11/2017] [Indexed: 01/20/2023]
Abstract
Recently developed lipids with the trans-2-aminocyclohexanol (TACH) moiety represent unique pH-sensitive conformational switches ("flipids") that can trigger the membrane of liposome-based drug delivery systems at lowered pH as seen in many pathological scenarios. A library of flipids with various TACH-based headgroups and hydrocarbon tails were designed, prepared, and characterized to systematically elucidate the relationship between their chemical structures and their ability to form and to trigger liposomes. Liposomes (fliposomes) consisting of a flipid, POPC and PEG-ceramide were stable at 4°C, pH 7.4 for up to several months and yet released the encapsulated fluorophore in seconds upon acidification. The colloidal properties and encapsulation efficiencies of the fliposomes depended on the structure features of the flipids such as the polarity of the headgroups and the shape and fluidity of the lipid tails. The pH-triggered release also depended on the flipid structure, where shorter linear tails yielded more efficient release. The release of fliposomes was enhanced at different narrow pH ranges, depending on the basicity of the flipid headgroup, which can be estimated either by calculated pKa or by acid/base titration of the flipids while its conformation is monitored by 1H NMR. The structure-activity relationship of the flipids supports "lipid tail conformational shortening" as the mechanism to disrupt lipid membranes and would provide great flexibility in the design of pH-sensitive drug delivery systems.
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Affiliation(s)
- Yu Zheng
- Department of Chemistry, College of the Pacific, University of the Pacific, 3601 Pacific Avenue, Stockton, CA 95211, USA; Department of Pharmaceutics and Medicinal Chemistry, Thomas J Long School of Pharmacy and Health Sciences, University of the Pacific, 751 Brookside Road, Stockton, CA 95211, USA
| | - Xin Liu
- Department of Chemistry, College of the Pacific, University of the Pacific, 3601 Pacific Avenue, Stockton, CA 95211, USA
| | - Nataliya M Samoshina
- Department of Chemistry, College of the Pacific, University of the Pacific, 3601 Pacific Avenue, Stockton, CA 95211, USA; Department of Pharmaceutics and Medicinal Chemistry, Thomas J Long School of Pharmacy and Health Sciences, University of the Pacific, 751 Brookside Road, Stockton, CA 95211, USA
| | - Vyacheslav V Samoshin
- Department of Chemistry, College of the Pacific, University of the Pacific, 3601 Pacific Avenue, Stockton, CA 95211, USA.
| | - Andreas H Franz
- Department of Chemistry, College of the Pacific, University of the Pacific, 3601 Pacific Avenue, Stockton, CA 95211, USA
| | - Xin Guo
- Department of Pharmaceutics and Medicinal Chemistry, Thomas J Long School of Pharmacy and Health Sciences, University of the Pacific, 751 Brookside Road, Stockton, CA 95211, USA.
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8
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Seydlova G, Beranova J, Bibova I, Dienstbier A, Drzmisek J, Masin J, Fiser R, Konopasek I, Vecerek B. The extent of the temperature-induced membrane remodeling in two closely related Bordetella species reflects their adaptation to diverse environmental niches. J Biol Chem 2017; 292:8048-8058. [PMID: 28348085 DOI: 10.1074/jbc.m117.781559] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 03/23/2017] [Indexed: 01/06/2023] Open
Abstract
Changes in environmental temperature represent one of the major stresses faced by microorganisms as they affect the function of the cytoplasmic membrane. In this study, we have analyzed the thermal adaptation in two closely related respiratory pathogens Bordetella pertussis and Bordetella bronchiseptica Although B. pertussis represents a pathogen strictly adapted to the human body temperature, B. bronchiseptica causes infection in a broad range of animals and survives also outside of the host. We applied GC-MS to determine the fatty acids of both Bordetella species grown at different temperatures and analyzed the membrane fluidity by fluorescence anisotropy measurement. In parallel, we also monitored the effect of growth temperature changes on the expression and production of several virulence factors. In response to low temperatures, B. pertussis adapted its fatty acid composition and membrane fluidity to a considerably lesser extent when compared with B. bronchiseptica Remarkably, B. pertussis maintained the production of virulence factors at 24 °C, whereas B. bronchiseptica cells resumed the production only upon temperature upshift to 37 °C. This growth temperature-associated differential modulation of virulence factor production was linked to the phosphorylation state of transcriptional regulator BvgA. The observed differences in low-temperature adaptation between B. pertussis and B. bronchiseptica may result from selective adaptation of B. pertussis to the human host. We propose that the reduced plasticity of the B. pertussis membranes ensures sustained production of virulence factors at suboptimal temperatures and may play an important role in the transmission of the disease.
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Affiliation(s)
- Gabriela Seydlova
- From the Department of Genetics and Microbiology, Faculty of Science, Charles University, Vinicna 5, 12843 Prague, Czech Republic
| | - Jana Beranova
- From the Department of Genetics and Microbiology, Faculty of Science, Charles University, Vinicna 5, 12843 Prague, Czech Republic
| | - Ilona Bibova
- the Laboratories of Post-transcriptional Control of Gene Expression and
| | - Ana Dienstbier
- the Laboratories of Post-transcriptional Control of Gene Expression and
| | - Jakub Drzmisek
- the Laboratories of Post-transcriptional Control of Gene Expression and
| | - Jiri Masin
- Molecular Biology of Bacterial Pathogens, Institute of Microbiology v.v.i., Academy of Sciences of the Czech Republic, Videnska 1083, 14220 Prague, Czech Republic
| | - Radovan Fiser
- From the Department of Genetics and Microbiology, Faculty of Science, Charles University, Vinicna 5, 12843 Prague, Czech Republic
| | - Ivo Konopasek
- From the Department of Genetics and Microbiology, Faculty of Science, Charles University, Vinicna 5, 12843 Prague, Czech Republic
| | - Branislav Vecerek
- the Laboratories of Post-transcriptional Control of Gene Expression and
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9
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trans-2-Aminocyclohexanol-based amphiphiles as highly efficient helper lipids for gene delivery by lipoplexes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:3113-25. [DOI: 10.1016/j.bbamem.2015.08.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 08/26/2015] [Accepted: 08/28/2015] [Indexed: 11/17/2022]
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10
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Poger D, Mark AE. A ring to rule them all: the effect of cyclopropane Fatty acids on the fluidity of lipid bilayers. J Phys Chem B 2015; 119:5487-95. [PMID: 25804677 DOI: 10.1021/acs.jpcb.5b00958] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cyclopropane fatty acids are widespread in bacteria. As their concentration increases on exposure to hostile environments, they have been proposed to protect membranes. Here, the effect of cyclopropane and unsaturated fatty acids, both in cis and trans configurations, on the packing, order, and fluidity of lipid bilayers is explored using molecular dynamics simulations. It is shown that cyclopropane fatty acids disrupt lipid packing, favor the occurrence of gauche defects in the chains, and increase the lipid lateral diffusion, suggesting that they enhance fluidity. At the same time, they generally induce a greater degree of order than unsaturated fatty acids of the same configuration and limit the rotation about the bonds surrounding the cyclopropane ring. This indicates that cyclopropane fatty acids may fulfill a dual function: stabilizing membranes against adverse conditions while simultaneously promoting their fluidity. Marked differences in the effect of cis- and trans-monocyclopropanated fatty acids were also observed, suggesting that they may play alternative roles in membranes.
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Affiliation(s)
- David Poger
- †School of Chemistry and Molecular Biosciences and ‡Institute for Molecular Bioscience, The University of Queensland, Brisbane QLD 4072, Australia
| | - Alan E Mark
- †School of Chemistry and Molecular Biosciences and ‡Institute for Molecular Bioscience, The University of Queensland, Brisbane QLD 4072, Australia
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11
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Salvati Manni L, Zabara A, Osornio YM, Schöppe J, Batyuk A, Plückthun A, Siegel JS, Mezzenga R, Landau EM. Phase Behavior of a Designed Cyclopropyl Analogue of Monoolein: Implications for Low-Temperature Membrane Protein Crystallization. Angew Chem Int Ed Engl 2014; 54:1027-31. [DOI: 10.1002/anie.201409791] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Indexed: 11/12/2022]
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12
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Salvati Manni L, Zabara A, Osornio YM, Schöppe J, Batyuk A, Plückthun A, Siegel JS, Mezzenga R, Landau EM. Phase Behavior of a Designed Cyclopropyl Analogue of Monoolein: Implications for Low-Temperature Membrane Protein Crystallization. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201409791] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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13
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Conformational folding of mycobacterial methoxy- and ketomycolic acids facilitated by α-methyl trans-cyclopropane groups rather than cis-cyclopropane units. Microbiology (Reading) 2013; 159:2405-2415. [DOI: 10.1099/mic.0.068866-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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14
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Matsuki H, Goto M, Tada K, Tamai N. Thermotropic and barotropic phase behavior of phosphatidylcholine bilayers. Int J Mol Sci 2013; 14:2282-302. [PMID: 23348926 PMCID: PMC3587988 DOI: 10.3390/ijms14022282] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 01/11/2013] [Accepted: 01/15/2013] [Indexed: 11/17/2022] Open
Abstract
Bilayers formed by phospholipids are frequently used as model biological membranes in various life science studies. A characteristic feature of phospholipid bilayers is to undergo a structural change called a phase transition in response to environmental changes of their surroundings. In this review, we focus our attention on phase transitions of some major phospholipids contained in biological membranes, phosphatidylcholines (PCs), depending on temperature and pressure. Bilayers of dipalmitoylphosphatidylcholine (DPPC), which is the most representative lipid in model membrane studies, will first be explained. Then, the bilayer phase behavior of various kinds of PCs with different molecular structures is revealed from the temperature-pressure phase diagrams, and the difference in phase stability among these PC bilayers is discussed in connection with the molecular structure of the PC molecules. Furthermore, the solvent effect on the phase behavior is also described briefly.
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Affiliation(s)
- Hitoshi Matsuki
- Department of Life System, Institute of Technology and Science, The University of Tokushima, 2-1 Minamijosanjima-cho, Tokushima 770-8506, Japan; E-Mails: (M.G.); (N.T.)
| | - Masaki Goto
- Department of Life System, Institute of Technology and Science, The University of Tokushima, 2-1 Minamijosanjima-cho, Tokushima 770-8506, Japan; E-Mails: (M.G.); (N.T.)
| | - Kaori Tada
- Department of Material Science and Technology, Kochi National College of Technology, 200-1 Monobe-otsu, Nankoku, Kochi 783-8508, Japan; E-Mail:
| | - Nobutake Tamai
- Department of Life System, Institute of Technology and Science, The University of Tokushima, 2-1 Minamijosanjima-cho, Tokushima 770-8506, Japan; E-Mails: (M.G.); (N.T.)
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15
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Schmidt ML, Ziani L, Boudreau M, Davis JH. Phase equilibria in DOPC/DPPC: Conversion from gel to subgel in two component mixtures. J Chem Phys 2009; 131:175103. [DOI: 10.1063/1.3258077] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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16
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Loffhagen N, Härtig C, Geyer W, Voyevoda M, Harms H. Competition betweencis, trans and Cyclopropane Fatty Acid Formation and its Impact on Membrane Fluidity. Eng Life Sci 2007. [DOI: 10.1002/elsc.200620168] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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17
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Jing B, Tokutake N, McCullough DH, Regen SL. A Quantitative Assessment of the Influence of Permanent Kinks on the Mixing Behavior of Phospholipids in Cholesterol-Rich Bilayers. J Am Chem Soc 2004; 126:15344-5. [PMID: 15563137 DOI: 10.1021/ja044517c] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The mixing behavior of a phospholipid containing a cis-cyclopropyl moiety (1) with one that contains two myristoyl groups (3a) has been investigated in fluid bilayers via the nearest-neighbor recognition (NNR) method. In the absence of cholesterol, these lipids mix ideally. In the presence of cholesterol, they show a modest preference for homo-phospholipid association. A trans-form of 1 (i.e., 2) was found to have similar behavior, except that the influence of cholesterol in promoting homo-phospholipid association was greater. Similar results have been found in membranes in which 3a is replaced with a phospholipid bearing two palmitoyol chains (3b). In this case, the effect of the kink is approximately twice as great. The implications of these findings, with respect to the "trans-fatty acid debate", are briefly discussed
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Affiliation(s)
- Bingwen Jing
- Department of Chemistry, Lehigh University, Bethlehem, PA 18015, USA
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18
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Kremer L, Guérardel Y, Gurcha SS, Locht C, Besra GS. Temperature-induced changes in the cell-wall components of Mycobacterium thermoresistibile. MICROBIOLOGY (READING, ENGLAND) 2002; 148:3145-3154. [PMID: 12368448 DOI: 10.1099/00221287-148-10-3145] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The mycobacterial cell wall consists of a core composed of peptidoglycan linked to the heteropolysaccharide arabinogalactan, which in turn is attached to mycolic acids. A variety of free lipids complements the mycolyl residues, whereas phosphatidylinositol mannosides (PIMs), lipoarabinomannan and proteins are interspersed in this framework. As a consequence, the cell envelope is extremely rich in lipids and early work has shown that the lipid content may vary with environmental conditions. To extend these studies, the influence of growth temperature on cell envelope components in Mycobacterium thermoresistibile, a temperature-resistant mycobacterial species, was investigated. Mycolic acid synthesis was reduced at 55 degrees C compared to 37 degrees C and the production of fatty acids, presumably precursors of mycolic acids, was increased. Since fatty acids are elongated by the type II fatty acid synthase complex and consequently by a mycobacterial beta-ketoacyl acyl carrier protein synthase (KasA), leading to mycolic acids, the expression level of KasA was analysed by Western blotting. KasA expression was significantly decreased at 55 degrees C over 37 degrees C. Important changes in the mycolic acid composition were observed and characterized by reduced levels of cyclopropanation and the concomitant accumulation of the cis-olefin derivatives. In addition, striking differences involved in complex lipid composition, including acylated trehaloses and trehalose dimycolate (TDM) were also observed. At 55 degrees C, M. thermoresistibile produced less TDM than at 37 degrees C, which could be explained by the down-regulation of antigen 85 (Ag85) expression as shown by Western blotting. The Ag85 complex represents a family of proteins known to catalyse the transfer of mycolates to trehalose, thereby generating TDM. Furthermore, at 55 degrees C the level of phosphatidyl-inositol hexamannoside (PIM(6)) synthesis, but not that of other PIM species, was dramatically reduced. This observation could be correlated to a decrease of mannosyltransferase activity associated with membranes prepared from cells grown at 55 degrees C as compared to 37 degrees C. Altogether, this study suggests that mycobacteria are capable of inducing important cell-wall changes in response to temperature variations, which may represent a strategy developed by the bacteria to adapt to environmental changes.
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Affiliation(s)
- Laurent Kremer
- Laboratoire des Mécanismes Moléculaires de la Pathogénie Microbienne, INSERM U447, Institut Pasteur de Lille/IBL, 1 rue du Pr. Calmette, BP245-59019 Lille Cedex, France1
| | - Yann Guérardel
- Laboratoire de Glycobiologie Structurale et Fonctionnelle, CNRS UMR8576, Université des Sciences et Technologies de Lille, F-59655 Villeneuve d'Ascq Cedex, France2
| | - Sudagar S Gurcha
- School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK3
| | - Camille Locht
- Laboratoire des Mécanismes Moléculaires de la Pathogénie Microbienne, INSERM U447, Institut Pasteur de Lille/IBL, 1 rue du Pr. Calmette, BP245-59019 Lille Cedex, France1
| | - Gurdyal S Besra
- School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK3
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19
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Olbrich K, Rawicz W, Needham D, Evans E. Water permeability and mechanical strength of polyunsaturated lipid bilayers. Biophys J 2000; 79:321-7. [PMID: 10866958 PMCID: PMC1300936 DOI: 10.1016/s0006-3495(00)76294-1] [Citation(s) in RCA: 342] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Micropipette aspiration was used to test mechanical strength and water permeability of giant-fluid bilayer vesicles composed of polyunsaturated phosphatidylcholine PC lipids. Eight synthetic-diacyl PCs were chosen with 18 carbon chains and degrees of unsaturation that ranged from one double bond (C18:0/1, C18:1/0) to six double bonds per PC molecule (diC18:3). Produced by increasing pipette pressurization, membrane tensions for lysis of single vesicles at 21 degrees C ranged from approximately 9 to 10 mN/m for mono- and dimono-unsaturated PCs (18:0/1, 18:1/0, and diC18:1) but dropped abruptly to approximately 5 mN/m when one or both PC chains contained two cis-double bonds (C18:0/2 and diC18:2) and even lower approximately 3 mN/m for diC18:3. Driven by osmotic filtration following transfer of individual vesicles to a hypertonic environment, the apparent coefficient for water permeability at 21 degrees C varied modestly in a range from approximately 30 to 40 microm/s for mono- and dimono-unsaturated PCs. However, with two or more cis-double bonds in a chain, the apparent permeability rose to approximately 50 microm/s for C18:0/2, then strikingly to approximately 90 microm/s for diC18:2 and approximately 150 microm/s for diC18:3. The measurements of water permeability were found to scale exponentially with the reduced temperatures reported for these lipids in the literature. The correlation supports the concept that increase in free volume acquired in thermal expansion above the main gel-liquid crystal transition of a bilayer is a major factor in water transport. Taken together, the prominent changes in lysis tension and water permeability indicate that major changes occur in chain packing and cohesive interactions when two or more cis-double bonds alternate with saturated bonds along a chain.
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Affiliation(s)
- K Olbrich
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708-0300, USA
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20
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Effect of unsaturated acyl chains on the thermotropic and barotropic phase transitions of phospholipid bilayer membranes. Chem Phys Lipids 1999. [DOI: 10.1016/s0009-3084(99)00050-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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21
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Chang YY, Cronan JE. Membrane cyclopropane fatty acid content is a major factor in acid resistance of Escherichia coli. Mol Microbiol 1999; 33:249-59. [PMID: 10411742 DOI: 10.1046/j.1365-2958.1999.01456.x] [Citation(s) in RCA: 295] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cyclopropane fatty acid (CFA) formation is a post-synthetic modification of the lipid bilayer that occurs as cultures of Escherichia coli and many other bacteria enter stationary phase. We report the first distinct phenotype for this membrane modification; early stationary phase cultures of strains lacking CFA (as a result of a null mutation in the cfa gene) are abnormally sensitive to killing by a rapid shift from neutral pH to pH 3. This sensitivity to acid shock is dependent on CFA itself because resistance to acid shock is restored to cfa mutant strains by incorporation of CFAs from the growth medium or by introduction of a functional cfa gene on a plasmid. The synthesis of CFA depends in part on the RpoS sigma factor, but the role of RpoS in resistance to acid shock involves additional factors because strains with null mutations in both cfa and rpoS are more sensitive to acid shock than either single mutant strain. Exponential phase cultures of E. coli are much more sensitive to acid shock than stationary phase cultures, but survival is greatly increased if the exponential phase cultures are exposed to moderately acid conditions (pH 5) before shift to pH 3. We show that exposure to moderately acid conditions gives a marked increase in cfa transcription. The efficiency of the survival of acid shock is extremely strain dependent, even among putative wild-type strains. Much, but not all, of this variability can be explained by the partially or totally defective RpoS alleles carried by many strains.
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Affiliation(s)
- Y Y Chang
- Department of Microbiology, University of Illinois, Urbana 61801, USA
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22
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Kaneshina S, Ichimori H, Hata T, Matsuki H. Barotropic phase transitions of dioleoylphosphatidylcholine and stearoyl-oleoylphosphatidylcholine bilayer membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1374:1-8. [PMID: 9814847 DOI: 10.1016/s0005-2736(98)00122-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In order to understand the effect of cis unsaturation on the thermotropic and barotropic phase behavior of phospholipid bilayer membranes, the phase transitions of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC), 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) bilayer membranes were observed by high-pressure optical method. With respect to DOPC bilayer membrane, the so-called main transition between the liquid crystalline (Lalpha) and the lamellar gel (Lbeta) phases was observed in water at above 0 degrees C under high pressure, in addition to the transition between the Lalpha and the lamellar crystalline (L(C)) phases in 50% aqueous ethylene glycol. The pressure of main transition increased linearly with an increase in temperature. Extrapolation of temperature (T)-pressure (P) phase boundary to ambient pressure suggests the temperature of the main transition to be -40.3 degrees C, which has never been found by the DSC method. On the other hand, the temperature of L(C)/Lalpha phase transition in 50% aqueous ethylene glycol was found to be -12.0 degrees C at ambient pressure. The main transition temperatures for DSPC, SOPC and DOPC are 55.6, 6.7 and -40.3 degrees C, respectively, at ambient pressure. The substitution of cis unsaturated chain for saturated chains of DSPC brings about the depression of the main transition temperature by about 48 (+/-1) degrees C for each chain. The volume changes (deltaV) associated with the transitions were calculated from the transition enthalpy (deltaH) and the slope of T-P diagram (dT/dP) by means of the Clapeyron-Clausius equation. The value of deltaV for the main transition of SOPC bilayer membranes was reduced to half the volume change for DSPC bilayers, which means the introduction of the cis double bond in the acyl chain of lipids brings about the reduction of deltaV because of the disordered packing of unsaturated chains in the gel phase of lipid bilayer membranes.
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Affiliation(s)
- S Kaneshina
- Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima, Japan
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23
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Pohle W, Selle C, Fritzsche H, Binder H. Fourier transform infrared spectroscopy as a probe for the study of the hydration of lipid self-assemblies. I. Methodology and general phenomena. BIOSPECTROSCOPY 1998; 4:267-80. [PMID: 9706385 DOI: 10.1002/(sici)1520-6343(1998)4:4<267::aid-bspy5>3.0.co;2-#] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An algorithm for the study of the gradual hydration of phospholipid assemblies by means of Fourier transform infrared (FTIR) spectroscopy is presented. A complete series of diacyl phosphatidylcholines (PCs) including all possible analogues with palmitoyl and oleoyl residues, namely DPPC, DOPC, POPC, and OPPC, was investigated at room temperature. The lipid samples were prepared as cast films probably consisting of aligned multilamellar bilayers. The range of water activities studied in these films was regulated by adsorption via the gas phase corresponding to relative humidities of between 0 and 100%. Analyses of the IR-spectroscopic data have concentrated mainly on determining the amounts of water incorporated by each lipid as well as the hydration-induced response observed for some absorption bands of the different lipids. The water uptake at high relative humidity (RH) increases with the portion of unsaturated acyl chains in the molecular structure of the PCs. Isothermal phase transitions triggered lyotropically have been detected in demonstrating the occurrence of the main transition in POPC and OPPC films at room temperature. Moreover, it appears that both lamellar phases, the gel as well as the liquid-crystalline phase, are not uniform. They seem to comprise an amazingly large span of order/disorder states of the lipid chains generally depending on the degree of hydration. As exemplified by the significant variation in the onset of wavenumber shifts for the PO2- and C=O stretching-vibration modes, obtained as a function of hydration, a sequence of attachment to polar lipid binding sites by water molecules was established for DPPC.
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Affiliation(s)
- W Pohle
- Friedrich-Schiller University Jena, Department of Biophysical Chemistry, Germany.
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24
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Barry CE, Lee RE, Mdluli K, Sampson AE, Schroeder BG, Slayden RA, Yuan Y. Mycolic acids: structure, biosynthesis and physiological functions. Prog Lipid Res 1998; 37:143-79. [PMID: 9829124 DOI: 10.1016/s0163-7827(98)00008-3] [Citation(s) in RCA: 388] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Affiliation(s)
- C E Barry
- Tuberculosis Research Section, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT 59840, USA.
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25
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Koynova R, Caffrey M. Phases and phase transitions of the phosphatidylcholines. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1376:91-145. [PMID: 9666088 DOI: 10.1016/s0304-4157(98)00006-9] [Citation(s) in RCA: 786] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
LIPIDAT (http://www.lipidat.chemistry.ohio-state.edu) is an Internet accessible, computerized relational database providing access to the wealth of information scattered throughout the literature concerning synthetic and biologically derived polar lipid polymorphic and mesomorphic phase behavior and molecular structures. Here, a review of the data subset referring to phosphatidylcholines is presented together with an analysis of these data. This subset represents ca. 60% of all LIPIDAT records. It includes data collected over a 43-year period and consists of 12,208 records obtained from 1573 articles in 106 different journals. An analysis of the data in the subset identifies trends in phosphatidylcholine phase behavior reflecting changes in lipid chain length, unsaturation (number, isomeric type and position of double bonds), asymmetry and branching, type of chain-glycerol linkage (ester, ether, amide), position of chain attachment to the glycerol backbone (1,2- vs. 1,3-) and head group modification. Also included is a summary of the data concerning the effect of pressure, pH, stereochemical purity, and different additives such as salts, saccharides, amino acids and alcohols, on phosphatidylcholine phase behavior. Information on the phase behavior of biologically derived phosphatidylcholines is also presented. This review includes 651 references.
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Affiliation(s)
- R Koynova
- Institute of Biophysics, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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26
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Pohle W, Selle C, Fritzsche H, Binder H. Fourier transform infrared spectroscopy as a probe for the study of the hydration of lipid self-assemblies. I. Methodology and general phenomena. ACTA ACUST UNITED AC 1998. [DOI: 10.1002/(sici)1520-6343(1998)4:4<267::aid-bspy5>3.0.co;2-%23] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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27
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Williams WP, Cunningham BA, Wolfe DH, Derbyshire GE, Mant GR, Bras W. A combined SAXS/WAXS investigation of the phase behaviour of di-polyenoic membrane lipids. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1284:86-96. [PMID: 8865819 DOI: 10.1016/0005-2736(96)00117-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Real-time measurements of the SAXS/WAXS diffraction patterns of aqueous dispersions (1:1 wt/wt) of the di-polyenoic lipids di-18:2 PC, di-18:3 PC, di-18:2 PE and di-18:3 PE were made over the temperature range 10 degrees to about -80 degrees C. The results of these measurements were compared to similar measurements performed on the corresponding di-18:0 and di-18:1 derivatives. SAXS measurements of the temperature dependence of lamellar repeat distances show that the di-polyenoic lipids undergo broad second-order transitions between their gel and liquid-crystal lamellar phases spanning 30-40 degrees C. The di-18:1 and di-18:0 derivatives, in contrast, undergo abrupt first-order transitions. The gel phases of the di-18:0 derivatives are characterised by two-component WAXS patterns with a sharp component close to 0.42 nm and a broader component at narrower spacings. On cooling, these lipids appear to undergo an initial transition to an L beta, phase followed by a conversion to an Lc phase. The gel phases of the di-18:1 derivatives also show two-component patterns but with the sharp component centred closer to 0.44 nm. The di-polyenoic lipids, in contrast, are characterised by a single broad peak centred at a spacing of about 0.42 nm, close to that of conventional L beta phases. The changes in lamellar repeat distance accompanying the transitions in the di-monoenoic and di-polyenoic lipids, all of which occur in the frozen state, are very similar, indicating that the acyl chains of the polyenoic lipids are close to their maximum extension in the gel state. The WAXS patterns of the polyenoic lipids suggest that the saturated upper parts of the acyl chains are packed on a regular hexagonal lattice while their polyunsaturated termini remain relatively disordered.
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Affiliation(s)
- W P Williams
- Life Sciences Division, King's College London, UK
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28
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George KM, Yuan Y, Sherman DR, Barry CE. The biosynthesis of cyclopropanated mycolic acids in Mycobacterium tuberculosis. Identification and functional analysis of CMAS-2. J Biol Chem 1995; 270:27292-8. [PMID: 7592990 DOI: 10.1074/jbc.270.45.27292] [Citation(s) in RCA: 142] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The major mycolic acid produced by Mycobacterium tuberculosis contains two cis-cyclopropanes in the meromycolate chain. The gene whose product cyclopropanates the proximal double bond was cloned by homology to a putative cyclopropane synthase identified from the Mycobacterium leprae genome sequencing project. This gene, named cma2, was sequenced and found to be 52% identical to cma1 (which cyclopropanates the distal double bond) and 73% identical to the gene from M. leprae. Both cma genes were found to be restricted in distribution to pathogenic species of mycobacteria. Expression of cma2 in Mycobacterium smegmatis resulted in the cyclopropanation of the proximal double bond in the alpha 1 series of mycolic acids. Coexpression of both cyclopropane synthases resulted in cyclopropanation of both centers, producing a molecule structurally similar to the M. tuberculosis alpha-dicyclopropyl mycolates. Differential scanning calorimetry of purified cell walls and mycolic acids demonstrated that cyclopropanation of the proximal position raised the observed transition temperature by 3 degrees C. These results suggest that cyclopropanation contributes to the structural integrity of the cell wall complex.
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Affiliation(s)
- K M George
- Laboratory of Intracellular Parasites, NIAID, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana 59840, USA
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29
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Sanderson PW, Williams WP. Low-temperature phase behaviour of the major plant leaf lipid monogalactosyldiacylglycerol. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1107:77-85. [PMID: 1616928 DOI: 10.1016/0005-2736(92)90331-f] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Heating and cooling thermograms of unsaturated MGDG samples isolated from the leaves of Vicia faba are surprisingly featureless. This reflects the low enthalpies associated with phase transitions in highly unsaturated lipids and the fact that these transitions, in the case of MGDG, are to a large extent masked by those associated with the freezing and melting of ice. Careful choice of thermal heating/cooling regimes, combined with the use of real-time X-ray diffraction and freeze-fracture measurements, permits a detailed analysis of the phase behaviour of the system. The phase behaviour of unsaturated MGDG samples is shown to be basically similar to that seen in saturated MGDG samples. The lipid which exists in the inverted hexagonal (HexII) liquid crystal phase at room temperature forms a highly disordered lamellar gel (L beta) phase on cooling to temperatures below about -15 degrees C. On reheating, this first reorganizes at a temperature of about -10 degrees C to form a well-defined Lc1 phase. Above about -2 degrees C, this melts to re-form the HexII phase. Samples re-cooled from temperatures between -2 degrees C and 14 degrees C revert directly to the Lc1 phase while samples cooled from higher temperatures form the L beta phase. This reflects the fact that the former samples contain small amounts of unmelted Lc1 phase lipid. The implications of these observations are discussed in terms of the general problems associated with the measurement of low-temperature phase behaviour of membrane lipids.
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Affiliation(s)
- P W Sanderson
- Biomolecular Sciences Division, King's College London, UK
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30
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Seigneuret M, Neumann JM, Levy D, Rigaud JL. High-resolution 13C NMR study of the topography and dynamics of methionine residues in detergent-solubilized bacteriorhodopsin. Biochemistry 1991; 30:3885-92. [PMID: 2018760 DOI: 10.1021/bi00230a012] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The proton transport membrane protein bacteriorhodopsin has been biosynthetically labeled with [methyl-13C]methionine and studied by high-resolution 13C NMR after solubilization in the detergent Triton X-100. The nine methionine residues of bacteriorhodopsin give rise to four well-resolved 13C resonances, two of which are shifted upfield or downfield due to nearby aromatic residues. Methionine residues located on the hydrophilic surfaces, on the hydrophobic surface, and in the interior of the protein could be discriminated by studying the effects of papain proteolysis, glycerol-induced viscosity increase, and paramagnetic broadening by spin-labels on NMR spectra. Such data were used to evaluate current models of the bacteriorhodopsin transmembrane folding and tertiary structure. T2 and NOE measurements were performed to study the local dynamics of methionine residues in bacteriorhodopsin. For the detergent-solubilized protein, hydrophilic and hydrophobic external residues undergo a relatively large extent of side chain wobbling motion while most internal residues are less mobile. In the native purple membrane and in reconstituted bacteriorhodopsin liposomes, almost all methionine residues have their wobbling motion severely restricted, indicating a large effect of the membrane environment on the protein internal dynamics.
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Affiliation(s)
- M Seigneuret
- URA-CNRS 1290, CEN Saclay, Gif-sur-Yvette, France
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31
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Wong PT, Siminovitch DJ, Mantsch HH. Structure and properties of model membranes: new knowledge from high-pressure vibrational spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA 1988; 947:139-71. [PMID: 3278738 DOI: 10.1016/0304-4157(88)90023-8] [Citation(s) in RCA: 140] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- P T Wong
- Division of Chemistry, National Research Council of Canada, Ottawa, Ontario
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32
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Grogan DW, Cronan JE. Characterization of Escherichia coli mutants completely defective in synthesis of cyclopropane fatty acids. J Bacteriol 1986; 166:872-7. [PMID: 3519583 PMCID: PMC215207 DOI: 10.1128/jb.166.3.872-877.1986] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The synthesis of cyclopropane fatty acids (CFA) in bacteria represents a biochemically and physiologically unique membrane modification whose importance for the cell remains unknown, despite extensive study of a Cfa- mutant of Escherichia coli and of the cloned cfa gene. Recently we reported the isolation of new Cfa- mutants (D. W. Grogan and J. E. Cronan, Jr., Mol. Gen. Genet. 196:367-372, 1984). Molecular-genetic and biochemical analysis indicated that these were null mutants of the E. coli cfa locus which were formed by inversions of a chromosomal segment. Isogenic Cfa+ and Cfa- strains were constructed from one such mutant and subjected to various stress conditions. In nearly all cases, both strains responded equally, but certain treatments, such as repeated freezing and thawing, favored the survival of Cfa+ strains over Cfa- strains. Though not essential, CFA thus appeared to play some beneficial role (or roles) in the bacterial cell.
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Nuhn P, Brezesinski G, Dobner B, Förster G, Gutheil M, Dörfler HD. Synthesis, calorimetry, and X-ray diffraction of lecithins containing branched fatty acid chains. Chem Phys Lipids 1986; 39:221-36. [PMID: 3698145 DOI: 10.1016/0009-3084(86)90012-5] [Citation(s) in RCA: 71] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Lecithins with branched fatty acid chains were synthesized and characterized by differential scanning calorimetry and X-ray diffraction. The influence of three chemical alterations on the phase transition parameters were investigated: length of the branches in 2-position of the acyl chains, position of the branches in the acyl chains, and position of the branched fatty acid chains in the glycerol backbone. The results show that the branched phosphatidylcholines (PCs) have a reduced gel-to-liquid-crystalline phase transition temperature (Tm) compared to the corresponding straight-chain PCs. Depending on both the length of the branches in 2-position of the acyl chains and the position of the branches in the acyl chains, the Tm-values pass through a minimum. The systematic change of the main-transition temperatures Tm is connected with a modified structural polymorphism. If the length of the branches increases three types of polymorphism were observed.
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Rilfors L. Difference in packing properties between iso and anteiso methyl-branched fatty acids as revealed by incorporation into the membrane lipids of Acholeplasma laidlawii strain A. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 1985. [DOI: 10.1016/0005-2736(85)90228-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Perly B, Smith IC, Jarrell HC. Effects of replacement of a double bond by a cyclopropane ring in phosphatidylethanolamines: a 2H NMR study of phase transitions and molecular organization. Biochemistry 1985; 24:1055-63. [PMID: 3994990 DOI: 10.1021/bi00325a038] [Citation(s) in RCA: 73] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The thermotropic behavior and molecular properties of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) and 1-palmitoyl-2-dihydrosterculoyl-sn-glycero-3-phosphoethanolamine (PDSPE) have been investigated by 2H NMR spectroscopy using samples selectively labeled at the 5'-, 9'-, 10'-, and 16'-positions of the sn-2 chains. Comparison with the corresponding phosphocholine analogues (POPC and PDSPC), obtained as intermediate synthetic products, was used to monitor the role of the polar head group. Replacement of the choline moiety by ethanolamine increased the gel to liquid-crystal transition temperature by 10-32 degrees C and led to a significantly higher ordering of the fatty acyl chains in the liquid-crystalline bilayer state. The lateral compression effect, due to the smaller area per polar head group in PE, results in a bilayer to hexagonal phase transition at elevated temperatures. The effects on both PC and PE due to replacement of the olefinic group by a cyclopropane unit are similar. A decrease in the temperature of the gel to liquid-crystal phase transition, Tc, is observed upon introduction of a cyclopropane ring; it goes from 26 degrees C in POPE to approximately 10 degrees C in PDSPE. In addition, a very significant broadening of the transition profile is observed. These observations are consistent with the poor packing ability of mixed saturated and cyclopropane-containing chains due to the bulky substituent effect. The temperature of the bilayer-hexagonal phase transition of PE samples was decreased by 15-20 degrees C on replacement of oleoyl chains by dihydrosterculoyl chains at the sn-2 position.(ABSTRACT TRUNCATED AT 250 WORDS)
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Lytz RK, Reinert JC, Church SE, Wickman HH. Structural properties of a monobrominated analog of 1,2-dipalmitoyl-sn-glycero-3-phosphorylcholine. Chem Phys Lipids 1984; 35:63-76. [PMID: 6547644 DOI: 10.1016/0009-3084(84)90033-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Hydrated multibilayers of 1-palmitoyl-2-monobromopalmitoyl-sn-glycero-3-phosphorylcholine (BrDPPC), where the 2-chain is brominated at either the C-9 or C-10 position, have been studied by low and wide angle X-ray diffraction methods. Oriented and unoriented samples were investigated. The long spacing was observed over the temperature interval -15 degrees C to 80 degrees C. A monotonic increase from approx. 50 A to approx. 62 A (28 wt. % H2O) occurred with decreasing temperature. The BrDPPC showed no evidence of a sharp gel-to-liquid crystal phase transition. Wide angle scattering showed a diffuse peak corresponding to (4.5 A)-1. Differential scanning calorimetry measurements for hydrated liposomes (50 wt. % H2O) also showed no evidence for a phase transition (-40 less than or equal to T less than or equal to 60 degrees C). These results suggest a low temperature amorphous (glass) state for the acyl side chains of BrDPPC. Monolayer film properties of monobrominated stearic acid also reflect a chain disordering effect occurring upon midchain substitution.
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Grogan DW, Cronan JE. Cloning and manipulation of the Escherichia coli cyclopropane fatty acid synthase gene: physiological aspects of enzyme overproduction. J Bacteriol 1984; 158:286-95. [PMID: 6325391 PMCID: PMC215410 DOI: 10.1128/jb.158.1.286-295.1984] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Like many other eubacteria, cultures of Escherichia coli accumulate cyclopropane fatty acids (CFAs) at a well-defined stage of growth, due to the action of the cytoplasmic enzyme CFA synthase. We report the isolation of the putative structural gene, cfa, for this enzyme on an E. coli-ColE1 chimeric plasmid by the use of an autoradiographic colony screening technique. When introduced into a variety of E. coli strains, this plasmid, pLC18-11, induced corresponding increases in CFA content and CFA synthase activity. Subsequent manipulation of the cfa locus, facilitated by the insertion of pLC18-11 into a bacteriophage lambda vector, allowed genetic and physiological studies of CFA synthase in E. coli. Overproduction of this enzyme via multicopy cfa plasmids caused abnormally high levels of CFA in membrane phospholipid but no discernable growth perturbation. Infection with phage lambda derivatives bearing cfa caused transient overproduction of the enzyme, although pL-mediated expression of cfa could not be demonstrated in plasmids derived from such phages. CFA synthase specific activities could be raised to very high levels by using cfa runaway-replication plasmids. A variety of physiological factors were found to modulate the levels of CFA synthase in normal and gene-amplified cultures. These studies argue against several possible mechanisms for the temporal regulation of CFA formation.
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McElhaney RN. The structure and function of the Acholeplasma laidlawii plasma membrane. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 779:1-42. [PMID: 6318828 DOI: 10.1016/0304-4157(84)90002-9] [Citation(s) in RCA: 94] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Coolbear KP, Keough KM. Lipid oxidation and gel to liquid-crystalline transition temperatures of synthetic polyunsaturated mixed-acid phosphatidylcholines. BIOCHIMICA ET BIOPHYSICA ACTA 1983; 732:531-40. [PMID: 6871213 DOI: 10.1016/0005-2736(83)90229-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Synthetic preparations of the polyunsaturated phosphatidylcholines 1-stearoyl-2-linoleoyl-sn-glycero-3-phosphocholine (SLPC) and 1-stearoyl-2-alpha-linolenoyl-sn-glycero-3-phosphocholine (SLnPC) were observed to undergo autooxidation sometimes during synthesis and also on storage. Oxidation was also induced by treatment of unoxidized SLPC with ultraviolet irradiation. Oxidation was estimated by thin layer chromatographic, fatty acid and ultraviolet spectral analyses. With limited oxidation, the gel to liquid-crystalline transition temperatures of aqueous dispersions of these lipids were seen to increase. Extensive oxidation led to a reduction in the enthalpies of the transitions. The increases in transition temperatures were consistent with the presence of conjugated double bonds, as shown by increased absorption at 230 nm, and trans double bonds, in the oxidized lipids leading to the creation of more rigid domains within the bilayer. Some of the changes in the transitions, especially the decreasing enthalpy after extensive oxidation, may have occurred because of the presence of small amounts of lysophosphatidylcholine and other oxidation intermediates or breakdown products seen by thin layer analysis. Thermograms of mixtures of unoxidized SLPC with amounts of lysostearoylPC found in the oxidized samples showed, however, that lysoPC likely did not contribute significantly to the increase in transition temperatures. Thin layer analysis suggested that the presence of cross-linked products could have contributed to the observed thermotropic properties.
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Dufourc EJ, Smith IC, Jarrell HC. A 2H-NMR analysis of dihydrosterculoyl-containing lipids in model membranes: structural effects of a cyclopropane ring. Chem Phys Lipids 1983; 33:153-77. [PMID: 6627531 DOI: 10.1016/0009-3084(83)90019-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The molecular properties of lipid multilayers of 1-palmitoyl-2-[dideutero]dihydrosterculoyl-sn-glycero-3-phosphocholine (PDSPC) were investigated by means of 2H-NMR. The transition from the liquid-crystalline phase to a more highly ordered phase was found to take place between -10 degrees C and -15 degrees C. The temperature variation of the quadrupolar splittings of specifically dideuterated PDSPC molecules was analyzed in terms of 'segmental' and 'geometrical' order parameters: the lower half of the sn-2 chain (from the site of the cyclopropane ring to the terminal methyl group) was more conformationally disordered than the upper half. The apparently abnormal increase of the quadrupolar splitting of the pro-S deuteron at the C-2' position, with increasing temperature, was attributed to a change in the average orientation of that C-2H bond with respect to the axis of motion, resulting in an increase of the 'geometrical' order parameter, S gamma. The molecular order parameter matrix elements, Sij, of the cyclopropane ring were derived from the experimental SC-2H order parameters using similarity transformations. The matrix S was diagonalized and the molecular order parameter of the cyclopropane ring, Smol (or S*33), was determined by assuming axial symmetry for such matrices associated with molecules in a liquid-crystal medium. A value of Smol = 0.59 +/- 0.04 at 25 degrees C was thus calculated. This value represents a discontinuity in the positional dependence of the molecular order parameter for the sn-2 chain of PDSPC, indicating that the cyclopropane ring provides a rigid barrier separating the lipid bilayer into two regions: an ordered region from the bilayer surface to the site of the cyclopropane ring and a much more disordered region thereafter to the center of the bilayer.
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Coolbear KP, Berde CB, Keough KM. Gel to liquid-crystalline phase transitions of aqueous dispersions of polyunsaturated mixed-acid phosphatidylcholines. Biochemistry 1983; 22:1466-73. [PMID: 6838863 DOI: 10.1021/bi00275a022] [Citation(s) in RCA: 154] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The thermotropic properties of aqueous dispersions of synthetic mixed-acid polyunsaturated 1,2-diacyl-3-sn-phosphatidylcholines (PC) have been studied by differential scanning calorimetry. The gel to liquid-crystalline phase transition temperature (Tc) of 1-stearoyl-2-linoleoyl-sn-glycero-3-phosphocholine (SLPC) was -16.2 +/- 1.6 degrees C (means +/- SD, nine dispersions, three separate synthetic preparations); that for a preparation of 1-stearoyl-2-linolenoyl-PC (SLnPC) was -13 degrees C and for a preparation of 1-stearoyl-2-arachidonoyl-PC (SAPC) was -12.6 +/- 1.0 degrees C (three dispersions, one preparation). The temperatures of maximum heat flow (Tmax) for the lipid transitions were -14.4 +/- 1.3, -11, and -10.7 +/- 0.9 degrees C and the enthalpies were 3.3 +/- 1.0, 6.6, and 5.3 +/- 1.8 kcal X mol-1 for SLPC, SLnPC, and SAPC, respectively. The transition temperatures and enthalpies are rationalized on the basis of existing data on the effect of double-bond position on Tc and are interpreted with the use of a statistical mechanical model. The trend of the transition temperatures with the introduction of multiple double bonds reflects opposing effects due to increased molecular area and decreasing degrees of freedom of rotation about carbon-carbon bonds.
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Abstract
This review represents a personal view of membrane thermodynamics. I do not intend to deal at all with the irreversible thermodynamics of membrane mass transfer processes. This aspect has been covered far more competently and completely by other people (Bittar, 1970; Paterson, 1970; Rottenberg, Caplan & Essig, 1970; Mitchell, 1970; Rothschildet al.1980; Oster, Perelson & Katchalsky, 1973; Kedem & Katchalsky, 1958; Schwartz, 1971). The recent review on osmosis by Hill (1979) is a particularly succinct appraisal of a facet of irreversible membrane thermodynamics. Arata & Nishimura (1980) have considered the coupling of electron transfer to vectorial processes in biological membranes.
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Endo T, Inoue K, Nojima S, Terashima S, Oshima T. Synthesis and physical properties of phosphatidylcholines containing ω-cyclohexyl fatty acyl chains. Chem Phys Lipids 1982. [DOI: 10.1016/0009-3084(82)90019-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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McElhaney RN. The use of differential scanning calorimetry and differential thermal analysis in studies of model and biological membranes. Chem Phys Lipids 1982; 30:229-59. [PMID: 7046969 DOI: 10.1016/0009-3084(82)90053-6] [Citation(s) in RCA: 261] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Differential scanning calorimetry (DSC), and to a lesser extent differential thermal analysis (DTA), are powerful yet relatively rapid and inexpensive thermodynamic techniques for studying the thermotropic phase behavior of lipids in model and biological membranes, without the introduction of exogenous probe molecules. In this review the principles as well as the scope and limitations of DSC and DTA are discussed first. The application of these techniques to the study of the thermotropic phase behavior of aqueous dispersions of various single synthetic phospholipids are then summarized, and the effects of cholesterol, free fatty acids, lysophospholipids, drugs, anesthetics and proteins on the gel to liquid-crystalline phase transitions exhibited by these model systems are discussed. The phase mixing properties of model membranes consisting of mixtures of two or more synthetic or natural phospholipids are considered next. Finally, the thermotropic phase behavior of prokaryotic plasma membranes and of the plasma, microsomal and mitochondrial membranes of eukaryotic cells are reviewed, and the applications of DSC and DTA to study the thermal behavior of specific membrane proteins, as well as the physical properties of the membrane lipid phase, are summarized.
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Regulation of Bacterial Membrane Lipid Synthesis. ACTA ACUST UNITED AC 1982. [DOI: 10.1016/s0070-2161(08)60312-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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Blume A, Eibl H. A calorimetric study of the thermotropic behaviour of 1,2-dipentadecylmethylidene phospholipids. BIOCHIMICA ET BIOPHYSICA ACTA 1981; 640:609-18. [PMID: 7213906 DOI: 10.1016/0005-2736(81)90484-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Differential scanning calorimetry was used to study the thermotropic behaviour of 1,2-dipentadecylmethylidene phospholipids with various head groups. The structural variation in the glycerol backbone region leads to a strong restriction of conformational freedom for the first two methylene segments of the chains, so that dipentadecylmethylidene phospholipids show lower transition temperatures, lower enthalpies and lower cooperativity of the transition from the gel to the liquid crystalline phase. The extreme chemical stability of these lipids in the alkaline pH region enables investigations of phosphatidylethanolamine and phosphatidic acid dispersions at high pH values. Both phospholipids show a decrease in the transition temperature and in the transition enthalpy as they become singly and doubly charged, respectively. A complex behaviour of the transition enthalpy of doubly charged 1,2-dipentadecylmethylidene phosphatidic acid was observed when the NaCl concentration of the dispersion was increased.
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McGarrity JT, Armstrong JB. Phase transition behaviour of artificial liposomes composed of phosphatidylcholines acylated with cyclopropane fatty acids. BIOCHIMICA ET BIOPHYSICA ACTA 1981; 640:544-8. [PMID: 7213905 DOI: 10.1016/0005-2736(81)90478-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Phase transitions of liposomes composed of synthetic phoshatidylcholines acylated with the cyclopropane fatty acids, lactobacillic and dihydrosterculic acid, were studied by differential scanning calorimetry. Transition temperatures were approx. 16 degrees C higher than for phosphatidylcholines acylated with the corresponding unsaturated fatty acids, cis-vaccenic and oleic acid. Though our transition temperatures were all several degrees lower than those determined by Silvius and McElhaney ((1979) Chem. Phys. Lipids 25, 125--134), the increase produced by replacement of the double bond with a cyclopropane ring was the same. We propose that this replacement, through its effect on membrane fluidity, may serve to regulate the activity of membrane-associated processes such as transport.
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Silvius JR, Mak N, McElhaney RN. Lipid and protein composition and thermotropic lipid phase transitions in fatty acid-homogeneous membranes of Acholeplasma laidlawii B. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 597:199-215. [PMID: 7370250 DOI: 10.1016/0005-2736(80)90099-1] [Citation(s) in RCA: 73] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The membrane composition and lipid physical properties have been systematically investigated as a function of fatty acid composition for a series of Acholeplasma laidlawii B membrane preparations made homogeneous in various fatty acids by growing cells on single fatty acids and avidin, a potent fatty acid synthetic inhibitor. The membrane protein molecular weight distribution is essentially constant as a function of fatty acid composition, but the lipid/protein ratio varies over a 2-fold range when different fatty acid growth supplements are used. The membrane lipid head-group composition varies somewhat under these conditions, particularly in the ratio of the two major neutral glycolipids. Differential thermal analytical investigations of the thermotropic phase transitions of various combinations of membrane components suggest that these compositional changes are unlikely to result in qualitative changes in the nature of lipid-protein or lipid-lipid interactions, although lesser changes of a quantitative nature probably do occur. The total lipids of membranes made homogeneous in their lipid fatty acyl chain composition exhibit sharper than normal gel-to-liquid-crystalline phase transitions of which midpoint temperatures correlate very well with the phase transition temperatures of synthetic hydrated phosphatidylcholines with like acyl chains. Our results indicate that using avidin and suitable fatty acids to grow A. laidlawii B, it is possible to manipulate the position and the sharpness of the membrane lipid phase transition widely and independently without causing major modifications in other aspects of the membrane composition. This fact makes the fatty acid-homogeneous A. laidlawii B membrane a very useful biological membrane preparation in which to study lipid physical properties and their functional consequences.
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Silvius JR, McElhaney RN. Effects of phospholipid acyl chain structure on thermotropic phase properties. 3. Phosphatidylcholines with (−), and (±)-anteiso acyl chains. Chem Phys Lipids 1980. [DOI: 10.1016/0009-3084(80)90012-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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