DOCSLIB.ORG

（Original Papers） 宮崎玉樹，菅野仁美，阿曽幸男，合田幸広

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
（Original Papers） 宮崎玉樹，菅野仁美，阿曽幸男，合田幸広 148 国立医薬品食品衛生研究所報告 第137号（2019） 誌上発表（原著論文） Summaries of Papers Published in Other Journals（Original Papers） 宮崎玉樹，菅野仁美，阿曽幸男，合田幸広：国内で流 However, visual observation is subjective and vague 通している経皮吸収型製剤の粘着特性の比較 ―剥離 because color perception is organoleptic and color 力とタックについて―． is expressed by ambiguous names such as “orange- 薬学雑誌 2018;138（11）:1425-33. red” and “deep blue”. Quality management using Forty-four brands of transdermal patches for twelve the color of samples is gaining wider acceptance in kinds of active pharmaceutical ingredients（APIs） the field of natural products as well as industrial are available in Japan as of April 30, 2018. Although products because simple, easy to use, high-performance approximately one-third of the corresponding spectrophotometers are now widely used. In this pharmaceutical interview forms lack information on study, the color of iodine-starch reaction solution how to evaluate the adhesive properties of the patches, of 31 kinds of starches and pregelatinized starches the peel test, probe tack test, or inclined ball tack test from maize, wheat, potato and rice were measured have generally been adopted. This means that it might spectrophotometrically and the color was numerically be difficult to simply compare the adhesive properties described using the L＊a＊b＊ color system. The among the patches because the testing methods are characteristic（a ＊, b＊） values grouped together on not unified in some cases. In this study, measurements the color system according to the origin plant for each of the adhesive properties of 38 transdermal patches starch, suggesting that numerical information on the of ten different APIs were performed using several color reaction is useful for estimating the origins of unified testing methods（180˚ peel test, 90˚ peel test, starches. self-adhesion test, and probe tack test） under unified Keywords: starch, origin plant, L＊a＊b＊ color system experimental conditions. The adhesive properties were found to be quite different among the patches, even Otaki T＊1, Tanabe Y＊2, Kojima T＊1, Miura M＊1, for the same API, dose, and size. For example, the Ikeda Y＊1, Koide T, Fukami T＊2: In situ monitoring ratios of the maximum to minimum measured values of cocrystals in formulation development using low- of tack and 180˚ peel strength for tulobuterol patches frequency Raman spectroscopy. were 5 and 29, respectively. In the case of generic Int. J. Pharm. 2018;542（1-2）:56-65. products for which the bioequivalence to a brand-name In recent years, to guarantee a quality-by-design product is assured, the variation in adhesive properties approach to the development of pharmaceutical can extend the range of choices for patients, which products, it is important to identify properties of raw is advantageous. Providing information to medical materials and excipients in order to determine critical experts on adhesive properties through, for example, process parameters and critical quality attributes. pharmaceutical interview forms and package inserts, Feedback obtained from real-time analyses using is considered to be useful for helping patients to make various process analytical technology（PAT） tools better choices. has been actively investigated. In this study, in Keywords: transdermal patch, peel strength, tack situ monitoring using low-frequency（LF） Raman spectroscopy（10–200 cm−1）, which may have higher Miyazaki T, Aso Y, Goda Y: Identifying the origin discriminative ability among polymorphs than near- plant of starches by numerical description of the infrared spectroscopy and conventional Raman coloration of iodine-starch reaction solutions. spectroscopy（200–1800 cm−1）, was investigated as Jpn. J. Food Chem. Safety. 2018; 25（3）: 145-51. a possible application to PAT. This is because LF- Microscopy is the primary technique for identifying Raman spectroscopy obtains information about the origin plant of a starch sample but requires intermolecular and/or lattice vibrations in the solid state. operators with highly proficient skills and experience, The monitoring results obtained from Furosemide/ and is unsuitable for discriminating modified starches Nicotinamide cocrystal indicate that LF-Raman such as pregelatinized starches. The plant species spectroscopy is applicable to in situ monitoring of from which the starch is isolated is reflected in the suspension and fluidized bed granulation processes, characteristic color of the iodine-starch reaction solution. and is an effective technique as a PAT tool to detect the 誌 上 発 表 （原 著 論 文） 149 conversion risk of cocrystals. LF-Raman spectroscopy of ketoprofen with the pharmaceutical excipients or is also used as a PAT tool to monitor reactions, patch materials. crystallizations, and manufacturing processes of drug Keywords: ketoprofen dermal patch, Raman spectroscopy, substances and products. In addition, a sequence of skin permeability conversion behaviors of Furosemide/Nicotinamide cocrystals was determined by performing in situ ＊1 Meiji Pharmaceutical University monitoring for the first time. ＊2 Tornado Spectral Systems, Inc. Keywords: low-frequency Raman spectroscopy, process ＊3 Teikyo Heisei University analytical technology, monitoring ＊4 Nihon University ＊1 Takeda Pharmaceutical Company Yamamoto Y＊1, Hanai A＊1, Onuki Y＊2, Fujii M＊3, ＊2 Meiji Pharmaceutical University Onishi Y＊3, Fukami T＊3, Metori K＊4, Suzuki N＊4, Suzuki T＊4, Koide T: Mixtures of betamethasone Azuma M＊1 , Fujii M＊1 , Inoue M＊1 , Hisada H＊1 , butyrate propionate ointments and heparinoid oil- Koide T, Kemper M＊2, Yamamoto Y＊3, Suzuki N＊4, based cream: Physical stability evaluation. Suzuki T＊4, Fukami T＊1: Molecular state of active Euro. J. Pharm. Sci. 2018;124:199–207. pharmaceutical ingredients in ketoprofen dermal Betamethasone butyrate propionate ointment（BBPO） patches characterized by pharmaceutical evaluation. is mainly used for adult patients in dermatology and Biol. Pharm. Bull. 2018;41（9）:1348–54. is often prescribed as a mixture containing a base or The molecular states of ketoprofen and the interaction moisturizing cream for various reasons. However, in between ketoprofen and other pharmaceutical excipients the case of a moisturizing cream, since this formulation in the matrix layer were examined to determine their is composed of various ingredients, a physical change effect on the pharmaceutical properties of original and is expected to occur by mixing it with an ointment. generic ketoprofen dermal patches（generic patches Therefore, in the present study, the physical stability A and B）. Molecular states of ketoprofen were of a mixture of four BBPO formulations and heparinoid evaluated using polarized light microscopy, Raman oily cream（HPOC） was examined. Layer separation spectroscopy and powder X-ray diffraction. For the was observed in all mixtures following centrifugation. original ketoprofen patch, crystalline components were The near-infrared（NIR） measurement showed a peak not observed in the matrix layer. However, crystalline at 5200 cm−1 on the lower layer side, which strongly ketoprofen was observed in the two generic ketoprofen suggests the presence of water. The peak at 5200 cm−1 in patches. Moreover, the ketoprofen exhibited hydrogen the middle layer was hardly observed in the mixtures bonding with the pharmaceutical excipients or patch of two BBPO generic formulations and HPOC, thus materials in the generic products. Skin permeation suggesting that the separation was more advanced in of ketoprofen from the patches was evaluated using those mixtures than in the others. These two mixtures hairless mouse skin. Twelve hours after application, separated into a semisolid layer（upper side） and a the original patch demonstrated the highest level of liquid layer（lower side） after 3 h of storage at 37℃ . cumulative skin permeation of ketoprofen. This was The NIR measurement of each layer revealed that followed by generic patch B while generic patch most of the semisolid layer was oil while the liquid A showed the lowest level of permeation. Fluxes layer was water. Furthermore, backscattered light were calculated from the skin permeation profiles. measurements were conducted to monitor the behavior The original patch was approx. 2.4-times faster of the mixture’s layer separation. An evaluation compared with generic patch A and approximately using model formulations revealed that the layer 1.9-times faster compared with generic patch B. separation of the mixtures was due to the propylene This investigation suggested that pharmaceutical glycol（PG） and surfactant content of the two generic properties such as skin permeability for these types of BBPO formulations. Thus, these findings suggest products are affected by the precipitation of crystalline that excipients need to be considered in selecting ketoprofen in the matrix layer and the interaction formulations for mixtures of skin preparations. 150 国立医薬品食品衛生研究所報告 第137号（2019） Keywords: steroidal ointment, heparinoid oily cream, Sakai-Kato K, Nanjo K, Takechi-Haraya Y, Goda near-infrared spectroscopy Y, Okuda H, Izutsu K: Detailed morphological characterization of nanocrystalline active ingredients ＊1 Teikyo Heisei University in solid oral dosage forms using atomic force ＊2 University of Toyama microscopy. ＊3 Meiji Pharmaceutical University AAPS PharmSciTech. 2019;20:70. ＊4 Nihon University The characterization of nanocrystalline active ingredients in multicomponent formulations for the Inoue M＊1, Hisada H＊1, Koide T, Fukami T＊1, Roy design and manufacture of products with increased A＊2, Carriere J＊2, Heyler R＊2: Transmission
Load more

Recommended publications
  • Influence of Cholesterol on Phospholipid Bilayers Phase Domains As Detected by Laurdan Fluorescence
    120 Biophysical Journal Volume 66 January 1994 120-132 Influence of Cholesterol on Phospholipid Bilayers Phase Domains as Detected by Laurdan Fluorescence Tiziana Parasassi,* Massimo Di Stefano,* Marianna Loiero,* Giampietro Ravagnan,* and Enrico Grattont *Istituto di Medicina Sperimentale, Consiglio Nazionale Ricerche, 00137 Rome, Italy, and tLaboratory for Fluorescence Dynamics, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA ABSTRACT Coexisting gel and liquid-crystalline phospholipid phase domains can be observed in synthetic phospholipid vesicles during the transition from one phase to the other and, in vesicles of mixed phospholipids, at intermediate temperatures between the transitions of the different phospholipids. The presence of cholesterol perturbs the dynamic properties of both phases to such an extent as to prevent the detection of coexisting phases. 6-Lauroyl-2-dimethylaminonaphthalene (Laurdan) fluorescence offers the unique advantage of well resolvable spectral parameters in the two phospholipid phases that can be used for the detection and quantitation of coexisting gel and liquid-crystalline domains. From Laurdan fluorescence excitation and emission spectra, the generalized polarization spectra and values were calculated. By the generalized polarization phos- pholipid phase domain coexistence can be detected, and each phase can be quantitated. In the same phospholipid vesicles where without cholesterol domain coexistence can be detected, above 15 mol % and, remarkably, at physiological cholesterol concentrations,
    [Show full text]
  • Disruption of Membrane Cholesterol Organization Impairs the Concerted Activity of PIEZO1 Channel Clusters
    bioRxiv preprint doi: https://doi.org/10.1101/604488; this version posted April 11, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Disruption of membrane cholesterol organization impairs the concerted activity of PIEZO1 channel clusters P. Ridone1,*, E. Pandzic2,*, M. Vassalli3, C. D. Cox1,5, A. Macmillan2, P.A. Gottlieb4 and B. Martinac1,5 1The Victor Chang Cardiac Research Institute, Lowy Packer Building, Darlinghurst, NSW 2010, Australia, 2Biomedical Imaging Facility (BMIF), Mark Wainwright Analytical Centre, Lowy Cancer Research Centre, The University of New South Wales, NSW, 2052, Australia , 3Institute of Biophysics, National Research Council, Genova, Italy , 4Physiology and Biophysics, State University of New York at Buffalo, Buffalo, NY, 14214, USA , 5St Vincent's Clinical School, University of New South Wales, Darlinghurst, NSW 2010, Australia *These authors have equally contributed to this work Corresponding author: Dr. Boris Martinac Victor Chang Cardiac Research Institute Lowy Packer Building Darlinghurst, NSW 2010, Australia E-mail [email protected] Key words: Mechanosensitive channel, Cholesterol, STORM, Patch-Clamp, Fluorescence Microscopy. SUMMARY: The essential mammalian mechanosensitive channel PIEZO1 organizes in the plasma membrane into nanometric clusters which depend on the integrity of cholesterol domains to rapidly detect applied force and especially inactivate syncronously, the most commonly altered feature of PIEZO1 in pathology. 1 bioRxiv preprint doi: https://doi.org/10.1101/604488; this version posted April 11, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved.
    [Show full text]
  • New Insights on the Fluorescent Emission Spectra of Prodan and Laurdan
    J Fluoresc (2015) 25:621–629 DOI 10.1007/s10895-015-1545-x ORIGINAL PAPER New Insights on the Fluorescent Emission Spectra of Prodan and Laurdan Cíntia C. Vequi-Suplicy & Kaline Coutinho & M. Teresa Lamy Received: 12 December 2014 /Accepted: 23 February 2015 /Published online: 10 March 2015 # Springer Science+Business Media New York 2015 Abstract Prodan and Laurdan are fluorescent probes largely Introduction used in biological systems. They were synthetized to be sen- sitive to the environment polarity, and their fluorescent emis- The fluorescent probes Prodan (2-dimethylamino-6- sion spectrum shifts around 120 nm, from cyclohexane to propionylnaphthalene) and Laurdan (2-dimethylamino-6- water. Although accepted that their emission spectrum is com- dodecanoylnaphthalene) have been widely used in biological posed by two emission bands, the origin of these two bands is relevant systems [1–7]. They were synthetized [1]tobesen- still a matter of discussion. Here we analyze the fluorescent sitive to the environment polarity, so their emission spectra spectra of Prodan and Laurdan in solvents of different polar- shifts about 120 nm from cyclohexane to water [1, 8, 9]. ities, both by decomposing the spectrum into two Gaussian Moreover, when inserted into membranes, their emission bands and by computing the Decay Associated Spectra spectra is extremely dependent on the lipid bilayer phase (DAS), the latter with time resolved fluorescence. Our data (gel or fluid), the maximum of the spectrum shifting around show that the intensity of the lower energy emission band of 50 nm from one phase to the other [4, 6, 10]. Prodan and Laurdan (attributed, in the literature, to the decay Although Prodan and Laurdan have been extensively used, of a solvent relaxed state) is higher in cyclohexane than in their structure and electronic distribution, in different solvents, water, showing a decrease as the polarity of the medium in- are still a matter of discussion [11–13].
    [Show full text]
  • Biomimetic Curvature and Tension-Driven Membrane
    1 Biomimetic curvature and tension-driven membrane 2 fusion induced by silica nanoparticles 3 4 Marcos Arribas Perez1 and Paul A. Beales1,2,* 5 6 1 Astbury Centre for Structural Molecular Biology and School of Chemistry, University of Leeds, 7 Leeds, LS2 9JT, UK. 8 2 Bragg Centre for Materials Research, University of Leeds, Leeds, LS2 9JT, UK. 9 10 * Correspondence: [email protected] 11 12 1 13 Abstract 14 Membrane fusion is a key process to develop new technologies in synthetic biology, where 15 artificial cells function as biomimetic chemical microreactors. Fusion events in living cells are 16 intricate phenomena that require the coordinate action of multicomponent protein complexes. 17 However, simpler synthetic tools to control membrane fusion in artificial cells are highly desirable. 18 Native membrane fusion machinery mediates fusion driving a delicate balance of membrane 19 curvature and tension between two closely apposed membranes. Here we show that silica 20 nanoparticles (SiO2 NPs) at a size close to the cross-over between tension-driven and curvature- 21 driven interaction regimes initiate efficient fusion of biomimetic model membranes. Fusion 22 efficiency and mechanisms are studied by Förster Resonance Energy Transfer (FRET) and 23 confocal fluorescence microscopy. SiO2 NPs induce a slight increase in lipid packing likely to 24 increase the lateral tension of the membrane. We observe a connection between membrane 25 tension and fusion efficiency. Finally, real-time confocal fluorescence microscopy reveals three 26 distinct mechanistic pathways for membrane fusion. SiO2 NPs show significant potential for 27 inclusion in the synthetic biology toolkit for membrane remodelling and fusion in artificial cells.
    [Show full text]
  • Laurdan Fluorescence Lifetime Discriminates Cholesterol Content from Changes in Fluidity in Living Cell Membranes
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector 1238 Biophysical Journal Volume 104 March 2013 1238–1247 Laurdan Fluorescence Lifetime Discriminates Cholesterol Content from Changes in Fluidity in Living Cell Membranes Ottavia Golfetto, Elizabeth Hinde, and Enrico Gratton* Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, California ABSTRACT Detection of the fluorescent properties of Laurdan has been proven to be an efficient tool to investigate membrane packing and ordered lipid phases in model membranes and living cells. Traditionally the spectral shift of Laurdan’s emission from blue in the ordered lipid phase of the membrane (more rigid) toward green in the disordered lipid phase (more fluid) is quantified by the generalized polarization function. Here, we investigate the fluorescence lifetime of Laurdan at two different emission wavelengths and find that when the dipolar relaxation of Laurdan’s emission is spectrally isolated, analysis of the fluorescence decay can distinguish changes in membrane fluidity from changes in cholesterol content. Using the phasor representation to analyze changes in Laurdan’s fluorescence lifetime we obtain two different phasor trajectories for changes in polarity versus changes in cholesterol content. This gives us the ability to resolve in vivo membranes with different properties such as water content and cholesterol content and thus perform a more comprehensive analysis of cell membrane heterogeneity. We demon- strate this analysis in NIH3T3 cells using Laurdan as a biosensor to monitor changes in the membrane water content during cell migration. INTRODUCTION From the biological perspective, cell membranes influence that provide guidelines for understanding the complexity of many cell functions and are involved in most of the cellular cellular membranes.
    [Show full text]
  • Download Product Insert (PDF)
    PRODUCT INFORMATION Laurdan Item No. 19706 CAS Registry No.: 74515-25-6 Formal Name: 1-[6-(dimethylamino)-2-naphthalenyl]- O 1-dodecanone MF: C24H35NO FW: 353.5 Purity: ≥98% N UV/Vis.: λmax: 230, 250, 259, 284, 362 nm Supplied as: A crystalline solid Storage: -20°C Stability: ≥2 years Information represents the product specifications. Batch specific analytical results are provided on each certificate of analysis. Laboratory Procedures Laurdan is supplied as a crystalline solid. A stock solution may be made by dissolving the laurdan in the solvent of choice, which should be purged with an inert gas. Laurdan is soluble in the organic solvent chloroform at a concentration of approximately 10 mg/ml. Description Laurdan is a membrane-permeable fluorescent probe that displays spectral sensitivity to the phospholipid phase of the cell membrane to which it is bound.1 Quantitation of generalized polarization (GP) of laurdan can be used to identify phospholipid phase. When excited at 340 nm, GP values are 0.6 and -0.2 for gel phase and liquid crystalline phase, respectively. GP does not change with polar head group or pH (in the range 4-10); it changes only with phase state. Reference 1. Parasassi, T., De Stasio, G., Ravagnan, G., et al. Quantitation of lipid phases in phospholipid vesicles by the generalized polarization of Laurdan fluorescence. Biophys. J. 60(1), 179-189 (1991). WARNING CAYMAN CHEMICAL THIS PRODUCT IS FOR RESEARCH ONLY - NOT FOR HUMAN OR VETERINARY DIAGNOSTIC OR THERAPEUTIC USE. 1180 EAST ELLSWORTH RD SAFETY DATA ANN ARBOR, MI 48108 · USA This material should be considered hazardous until further information becomes available.
    [Show full text]
  • Laurdan Identifies Different Lipid Membranes in Eukaryotic Cells
    UC Irvine UC Irvine Previously Published Works Title Laurdan identifies different lipid membranes in eukaryotic cells Permalink https://escholarship.org/uc/item/9m80z238 ISBN 9781482209891 Authors Gratton, E Digman, MA Publication Date 2014 DOI 10.1201/b17634 License https://creativecommons.org/licenses/by/4.0/ 4.0 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Laurdan Identifies 13 Different Lipid Membranes in Eukaryotic Cells Enrico Gratton and Michelle A. Digman CONTENTS 13.1 Introduction ..................................................................................................283 13.1.1 Spectroscopic Properties of Laurdan................................................283 13.2 The Phasor Approach to Spectral and Lifetime Analysis ............................287 13.3 The Lifetime Phasor Transformation and Its Interpretation .........................289 13.4 Results of the Analysis of the Emission of Laurdan Using Spectral and Lifetime Phasors in GUVs Model Systems .................................................. 291 13.5 The Lifetime Phasor for Laurdan in GUVs ..................................................292 13.6 Live Cell Membrane Fluidity .......................................................................295 13.6.1 Spectral Phasors................................................................................295 13.6.2 Lifetime Phasors in Live 3T3 Cells ..................................................297 13.7 Conclusions and Further Considerations ......................................................299
    [Show full text]
  • UC Irvine UC Irvine Previously Published Works
    UC Irvine UC Irvine Previously Published Works Title Water dynamics in glycosphingolipid aggregates studied by LAURDAN fluorescence. Permalink https://escholarship.org/uc/item/2601m9d4 Journal Biophysical journal, 75(1) ISSN 0006-3495 Authors Bagatolli, LA Gratton, E Fidelio, GD Publication Date 1998-07-01 DOI 10.1016/s0006-3495(98)77517-4 License https://creativecommons.org/licenses/by/4.0/ 4.0 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Biophysical Journal Volume 75 July 1998 331–341 331 Water Dynamics in Glycosphingolipid Aggregates Studied by LAURDAN Fluorescence L. A. Bagatolli,*# E. Gratton,# and G. D. Fidelio* *Departamento de Quı´mica Biolo´ gica-CIQUIBIC, Facultad de Ciencias Quı´micas, Universidad Nacional de Co´ rdoba, Argentina and #Laboratory for Fluorescence Dynamics, University of Illinois at Urbana-Champaign, Urbana, Illinois USA ABSTRACT We have characterized the fluorescence properties of 6-dodecanoyl-2-dimethylamine-naphthalene (LAURDAN) in pure interfaces formed by sphingomyelin and 10 chemically related glycosphingolipids (GSLs).1 The GSLs contain neutral and anionic carbohydrate residues in their oligosaccharide chain. These systems were studied at temperatures below, at, or above the main phase transition temperature of the pure lipid aggregates. The extent of solvent dipolar relaxation around the excited fluorescence probe in the GSLs series increases with the magnitude of the glycosphingolipid polar headgroup below the transition temperature. This conclusion is based on LAURDAN’s excitation generalized polarization (GPex) and fluores- cence lifetime values found in the different interfaces. A linear dependence between the LAURDAN GPex and the intermo- lecular spacing among the lipid molecules was found for both neutral and anionic lipids in the GSLs series.
    [Show full text]
  • Naphthalene with Lipid Environments
    Photochemistry and Photobiology, 1999, 70(4): 557-564 A Model for the Interaction of 6-Lauroyl-2-(N,Ak dimethy1amino)naphthalenewith Lipid Environments: Implications for Spectral Properties Luis A. Bagatolliin2*,Tiziana Parasassi3,Gerard0 D. Fidelio2and Enrico Gratton’ ’Laboratory for Fluorescence Dynamics, University of Illinois at Urbana-Champaign, Urbana, IL, USA; *Departamento de Quimica Biol6gica-CIQUIBIC, Facultad de Ciencias Quimicas, Universidad Nacional de C6rdoba, Argentina and 31stituto di Medicina Sperimentale, CNR, Roma, Italy Received 27 January 1999; accepted 24 June 1999 ABSTRACT to proteins and associated with lipids (1-3). This family of probes includes 6-propionyl-2-(N,N-dimethylamino) Although 6-lauroyl-2-(N,N-dimethylamino)naphthalene naphthalene (PRODAN),? 6-lauroyl-2-(N,N-dimethylamino) (LAURDAN) is now widely used a probe for lipid sys- as naphthalene (LAURDAN) and 2’-(N,N-dimethylamino)-6- tems, most studies focus on the effect of the lipid envi- naphthoyl-4-trans-cyclohexanoic acid (DANCA) (Fig. 1). ronment on its emission properties but not on the exci- These probes all possess large excited-state dipoles. In polar tation properties. The present study is intended to inves- solvents, and when the molecular dynamics of solvent di- tigate the excitation properties of LAURDAN in diverse poles occur on the time scale of the probe’s fluorescence lipid environments. To this end, the fluorescence prop- lifetime, a reorientation of solvent dipoles around the probe erties of LAURDAN were studied in synthetic ester and excited-state dipole may occur. The energy required for this ether phosphatidylcholines and sphingomyelin vesicles reorientation results in a red shift of the fluorescence emis- below, at and above the corresponding lipid main phase- sion spectrum.
    [Show full text]
  • Evolutionarily Conserved Long-Chain Acyl- Coa Synthetases Regulate Membrane Composition and Fluidity
    RESEARCH ARTICLE Evolutionarily conserved long-chain Acyl- CoA synthetases regulate membrane composition and fluidity Mario Ruiz1†, Rakesh Bodhicharla1†, Marcus Sta˚ hlman2, Emma Svensk1, Kiran Busayavalasa1, Henrik Palmgren3, Hanna Ruhanen4,5, Jan Boren2, Marc Pilon1* 1Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden; 2Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden; 3Metabolism BioScience, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; 4Helsinki University Lipidomics Unit, Helsinki Institute for Life Science, Helsinki, Finland; 5Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland Abstract The human AdipoR1 and AdipoR2 proteins, as well as their C. elegans homolog PAQR- 2, protect against cell membrane rigidification by exogenous saturated fatty acids by regulating phospholipid composition. Here, we show that mutations in the C. elegans gene acs-13 help to suppress the phenotypes of paqr-2 mutant worms, including their characteristic membrane fluidity defects. acs-13 encodes a homolog of the human acyl-CoA synthetase ACSL1, and localizes to the mitochondrial membrane where it likely activates long chains fatty acids for import and *For correspondence: degradation. Using siRNA combined with lipidomics and membrane fluidity assays (FRAP and [email protected] Laurdan dye staining) we further show that the human ACSL1 potentiates lipotoxicity by the †These authors contributed saturated fatty acid palmitate: silencing ACSL1 protects against the membrane rigidifying effects of equally to this work palmitate and acts as a suppressor of AdipoR2 knockdown, thus echoing the C. elegans findings. Competing interest: See We conclude that acs-13 mutations in C.
    [Show full text]
  • Molecular Dynamics Simulations of Lipid Membranes
    MOLECULAR DYNAMICS SIMULATIONS OF LIPID MEMBRANES: THE EFFECTS OF PROBES, LIPID COMPOSITION AND PEPTIDES A Dissertation Presented to the Faculty of the Graduate School of Cornell University In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy by David Geoffrey Ackerman August 2015 © 2015 David Geoffrey Ackerman MOLECULAR DYNAMICS SIMULATIONS OF LIPID MEMBRANES: THE EFFECTS OF PROBES, LIPID COMPOSITION AND PEPTIDES David Geoffrey Ackerman, Ph.D. Cornell University 2015 The cell plasma membrane is comprised of hundreds of different lipid species as well as a variety of integral and peripheral proteins. The diversity of molecular constituents leads to the formation of functional lateral heterogeneities within the plane of the membrane, known as lipid rafts, which are distinct from the surrounding membrane. Given the complexity of the plasma membrane, and the importance of rafts in the life of a cell, simplified model mixtures capturing the characteristics of the plasma membrane have been essential for unraveling its underlying behavior. In this work, we use molecular dynamics simulations to study model membranes at resolutions not possible with experimental techniques. We first investigated a fundamental assumption in model membrane experiments: that extrinsic probes added to the membrane do not disrupt membrane behavior. We addressed this issue by simulating single component model membranes that contained commonly used fluorescent lipid analogs. We found that the probes are able to disorder the bilayer and reorient lipid headgroups due to the probes’ large, positively charged headgroups and long, interdigitating acyl chains. Importantly though, these effects die off within a couple of nanometers of the probe.
    [Show full text]
  • Alterations in the Properties of the Cell Membrane Due to Glycosphingolipid
    www.nature.com/scientificreports OPEN Alterations in the properties of the cell membrane due to glycosphingolipid accumulation in a Received: 3 October 2017 Accepted: 11 December 2017 model of Gaucher disease Published: xx xx xxxx Gyula Batta1,2, Lilla Soltész1, Tamás Kovács1, Tamás Bozó3, Zoltán Mészár4, Miklós Kellermayer 3, János Szöllősi1,5 & Peter Nagy 1 Gaucher disease is a lysosomal storage disease characterized by the malfunction of glucocerebrosidase resulting in the accumulation of glucosylceramide and other sphingolipids in certain cells. Although the disease symptoms are usually attributed to the storage of undigested substrate in lysosomes, here we show that glycosphingolipids accumulating in the plasma membrane cause profound changes in the properties of the membrane. The fuidity of the sphingolipid-enriched membrane decreased accompanied by the enlargement of raft-like ordered membrane domains. The mobility of non-raft proteins and lipids was severely restricted, while raft-resident components were only mildly afected. The rate of endocytosis of transferrin receptor, a non-raft protein, was signifcantly retarded in Gaucher cells, while the endocytosis of the raft-associated GM1 ganglioside was unafected. Interferon- γ-induced STAT1 phosphorylation was also signifcantly inhibited in Gaucher cells. Atomic force microscopy revealed that sphingolipid accumulation was associated with a more compliant membrane capable of producing an increased number of nanotubes. The results imply that glycosphingolipid accumulation in the plasma membrane has signifcant efects on membrane properties, which may be important in the pathogenesis of Gaucher disease. Te plasma membrane constitutes an interface between the cell and its surroundings, and it is the site of numer- ous transmembrane signaling and membrane trafcking events.
    [Show full text]