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Taylor JM, Conboy JC. Issues with lipid probes in flip-flop measurements: A comparative study using sum-frequency vibrational spectroscopy and second-harmonic generation. J Chem Phys 2024; 161:085104. [PMID: 39185850 DOI: 10.1063/5.0226075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Accepted: 08/11/2024] [Indexed: 08/27/2024] Open
Abstract
Fluorescent lipid probes such as 1-palmitoyl-2-(6-[7-nitro-2-1,3-benzoxadiazol-4-yl]amino-hexanoyl)-sn-glycero-3-phosphocholine (C6 NBD-PC) have been used extensively to study the kinetics of lipid flip-flop. However, the efficacy of these probes as reliable reporters of native lipid translocation has never been tested. In this study, sum-frequency vibrational spectroscopy (SFVS) was used to measure the kinetics of C6 NBD-PC lipid flip-flop and the flip-flop of native lipids in planar supported lipid bilayers. C6 NBD-PC was investigated at concentrations of 1 and 3 mol. % in both chain-matched 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and chain-mismatched 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) to assess the ability of C6 NBD-PC to mimic the behavior of the surrounding matrix lipids. It was observed that C6 NBD-PC exhibited faster flip-flop kinetics compared to the native lipids in both DPPC and DSPC matrices, with notably accelerated rates in the chain-mismatched DSPC system. SFVS was also used to measure the acyl chain orientation and gauche content of C6 NBD-PC in both DPPC and DSPC membranes. In the DSPC matrix (chain mismatched), C6 NBD-PC was more disordered in terms of both gauche content and acyl tilt, whereas it maintained an orientation similar to that of the native lipids in the DPPC matrix (chain matched). In addition, the flip-flop kinetics of C6 NBD-PC were also measured using second-harmonic generation (SHG) spectroscopy, by probing the motion of the NBD chromophore directly. The flip-flop kinetics measured by SHG were consistent with those obtained from SFVS. This study also marks the first instance of phospholipid flip-flop kinetics being measured via SHG. The results of this study clearly demonstrate that C6 NBD-PC does not adequately mimic the behavior of native lipids within a membrane. These findings also highlight the significant impact of the lipid matrix on the flip-flop behavior of the fluorescently labeled lipid, C6 NBD-PC.
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Affiliation(s)
- Joshua M Taylor
- Department of Chemistry, University of Utah, 315 South 1400 East RM. 2020, Salt Lake City, Utah 84112, USA
| | - John C Conboy
- Department of Chemistry, University of Utah, 315 South 1400 East RM. 2020, Salt Lake City, Utah 84112, USA
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2
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Herrera SA, Justesen BH, Dieudonné T, Montigny C, Nissen P, Lenoir G, Günther Pomorski T. Direct evidence of lipid transport by the Drs2-Cdc50 flippase upon truncation of its terminal regions. Protein Sci 2023; 33:e4855. [PMID: 38063271 PMCID: PMC10895448 DOI: 10.1002/pro.4855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Revised: 11/15/2023] [Accepted: 12/02/2023] [Indexed: 02/27/2024]
Abstract
P4-ATPases in complex with Cdc50 subunits are lipid flippases that couple ATP hydrolysis with lipid transport to the cytoplasmic leaflet of membranes to create lipid asymmetry. Such vectorial transport has been shown to contribute to vesicle formation in the late secretory pathway. Some flippases are regulated by autoinhibitory regions that can be destabilized by protein kinase-mediated phosphorylation and possibly by binding of cytosolic proteins. In addition, the binding of lipids to flippases may also induce conformational changes required for the activity of these transporters. Here, we address the role of phosphatidylinositol-4-phosphate (PI4P) and the terminal autoinhibitory tails on the lipid flipping activity of the yeast lipid flippase Drs2-Cdc50. By functionally reconstituting the full-length and truncated forms of Drs2 in a 1:1 complex with the Cdc50 subunit, we provide compelling evidence that lipid flippase activity is exclusively detected for the truncated Drs2 variant and is dependent on the presence of the phosphoinositide PI4P. These findings highlight the critical role of phosphoinositides as lipid co-factors in the regulation of lipid transport by the Drs2-Cdc50 flippase.
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Affiliation(s)
- Sara Abad Herrera
- Department of Molecular Biochemistry, Faculty of Chemistry and BiochemistryRuhr University BochumBochumGermany
| | - Bo Højen Justesen
- Department of Molecular Biochemistry, Faculty of Chemistry and BiochemistryRuhr University BochumBochumGermany
| | - Thibaud Dieudonné
- Université Paris‐Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC)Gif‐sur‐YvetteFrance
- DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
| | - Cédric Montigny
- Université Paris‐Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC)Gif‐sur‐YvetteFrance
| | - Poul Nissen
- DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
| | - Guillaume Lenoir
- Université Paris‐Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC)Gif‐sur‐YvetteFrance
| | - Thomas Günther Pomorski
- Department of Molecular Biochemistry, Faculty of Chemistry and BiochemistryRuhr University BochumBochumGermany
- Department of Plant and Environmental SciencesUniversity of CopenhagenFrederiksbergDenmark
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3
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Tomishige N, Bin Nasim M, Murate M, Pollet B, Didier P, Godet J, Richert L, Sako Y, Mély Y, Kobayashi T. HIV-1 Gag targeting to the plasma membrane reorganizes sphingomyelin-rich and cholesterol-rich lipid domains. Nat Commun 2023; 14:7353. [PMID: 37990014 PMCID: PMC10663554 DOI: 10.1038/s41467-023-42994-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 10/26/2023] [Indexed: 11/23/2023] Open
Abstract
Although the human immunodeficiency virus type 1 lipid envelope has been reported to be enriched with host cell sphingomyelin and cholesterol, the molecular mechanism of the enrichment is not well understood. Viral Gag protein plays a central role in virus budding. Here, we report the interaction between Gag and host cell lipids using different quantitative and super-resolution microscopy techniques in combination with specific probes that bind endogenous sphingomyelin and cholesterol. Our results indicate that Gag in the inner leaflet of the plasma membrane colocalizes with the outer leaflet sphingomyelin-rich domains and cholesterol-rich domains, enlarges sphingomyelin-rich domains, and strongly restricts the mobility of sphingomyelin-rich domains. Moreover, Gag multimerization induces sphingomyelin-rich and cholesterol-rich lipid domains to be in close proximity in a curvature-dependent manner. Our study suggests that Gag binds, coalesces, and reorganizes pre-existing lipid domains during assembly.
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Affiliation(s)
- Nario Tomishige
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France.
- Cellular Informatics Laboratory, RIKEN CPR, Wako, Saitama, Japan.
| | - Maaz Bin Nasim
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
- Faculty of Pharmacy, The University of Lahore, Lahore, Pakistan
| | - Motohide Murate
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
- Cellular Informatics Laboratory, RIKEN CPR, Wako, Saitama, Japan
| | - Brigitte Pollet
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Pascal Didier
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Julien Godet
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Ludovic Richert
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Yasushi Sako
- Cellular Informatics Laboratory, RIKEN CPR, Wako, Saitama, Japan
| | - Yves Mély
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France.
| | - Toshihide Kobayashi
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France.
- Cellular Informatics Laboratory, RIKEN CPR, Wako, Saitama, Japan.
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4
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Rajput D, Mahalingavelar P, Soppina V, Kanvah S. Improved lipophilic probe for visualizing lipid droplets in erastin-induced ferroptosis. Org Biomol Chem 2023; 21:8554-8562. [PMID: 37853800 DOI: 10.1039/d3ob01545a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
Studying the viscosity of lipid droplets (LDs) provides insights into various diseases associated with LD viscosity. Ferroptosis is one such process in which LD viscosity increases due to the abnormal accumulation of lipid ROS (reactive oxygen species) caused by peroxidation. For investigating the LD imaging and ferroptosis, we developed two molecules (NNS and DNS) that show significant Stokes shifts (182-232 nm) and utilized them for sub-cellular imaging. Excellent localization is noted with the lipid droplets. Subsequently, DNS was used to monitor the variations in the LD viscosity during erastin-induced ferroptosis followed by ferroptosis inhibition. Additionally, we explored variations in the LD quantity, size, and accumulation when subjected to oleic acid stimulation. Extensive DFT and TDDFT investigations have been employed to understand the effect of NO2 substitution on the linear and branched molecular derivatives. Our results with the improved lipophilic fluorophore, exhibiting excellent colocalization with LDs, offer valuable insights into sensing erastin-induced ferroptosis and have the potential for real-time diagnostic applications.
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Affiliation(s)
- Deeksha Rajput
- Department of Chemistry, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, Gujarat - 382055, India.
| | | | - Virupakshi Soppina
- Department of Biological Engineering, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, Gujarat-382055, India.
| | - Sriram Kanvah
- Department of Chemistry, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, Gujarat - 382055, India.
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5
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Rybak JA, Sahoo AR, Kim S, Pyron RJ, Pitts SB, Guleryuz S, Smith AW, Buck M, Barrera FN. Allosteric inhibition of the epidermal growth factor receptor through disruption of transmembrane interactions. J Biol Chem 2023; 299:104914. [PMID: 37315787 PMCID: PMC10362150 DOI: 10.1016/j.jbc.2023.104914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/16/2023] Open
Abstract
The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase (RTK) commonly targeted for inhibition by anticancer therapeutics. Current therapeutics target EGFR's kinase domain or extracellular region. However, these types of inhibitors are not specific for tumors over healthy tissue and therefore cause undesirable side effects. Our lab has recently developed a new strategy to regulate RTK activity by designing a peptide that specifically binds to the transmembrane (TM) region of the RTK to allosterically modify kinase activity. These peptides are acidity-responsive, allowing them to preferentially target acidic environments like tumors. We have applied this strategy to EGFR and created the PET1 peptide. We observed that PET1 behaves as a pH-responsive peptide that modulates the configuration of the EGFR TM through a direct interaction. Our data indicated that PET1 inhibits EGFR-mediated cell migration. Finally, we investigated the mechanism of inhibition through molecular dynamics simulations, which showed that PET1 sits between the two EGFR TM helices; this molecular mechanism was additionally supported by AlphaFold-Multimer predictions. We propose that the PET1-induced disruption of native TM interactions disturbs the conformation of the kinase domain in such a way that it inhibits EGFR's ability to send migratory cell signals. This study is a proof-of-concept that acidity-responsive membrane peptide ligands can be generally applied to RTKs. In addition, PET1 constitutes a viable approach to therapeutically target the TM of EGFR.
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Affiliation(s)
- Jennifer A Rybak
- Department of Genome Sciences and Technology, University of Tennessee, Knoxville, Tennessee, USA
| | - Amita R Sahoo
- Department of Physiology and Biophysics, Case Western Reserve University, School of Medicine, Cleveland, Ohio, USA
| | - Soyeon Kim
- Department of Chemistry, University of Akron, Akron, Ohio, USA
| | - Robert J Pyron
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Savannah B Pitts
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA
| | - Saffet Guleryuz
- Department of Medicine, University of Tennessee Graduate School of Medicine, Knoxville, Tennessee, USA
| | - Adam W Smith
- Department of Chemistry, University of Akron, Akron, Ohio, USA; Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, USA
| | - Matthias Buck
- Department of Physiology and Biophysics, Case Western Reserve University, School of Medicine, Cleveland, Ohio, USA
| | - Francisco N Barrera
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, USA.
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6
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Nordholt N, O'Hara K, Resch-Genger U, Blaskovich MAT, Rühle B, Schreiber F. A fluorescently labelled quaternary ammonium compound (NBD-DDA) to study resistance mechanisms in bacteria. Front Microbiol 2022; 13:1023326. [PMID: 36504769 PMCID: PMC9731378 DOI: 10.3389/fmicb.2022.1023326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 10/21/2022] [Indexed: 11/26/2022] Open
Abstract
Quaternary ammonium compounds (QACs) are widely used as active agents in disinfectants, antiseptics, and preservatives. Despite being in use since the 1940s, there remain multiple open questions regarding their detailed mode-of-action and the mechanisms, including phenotypic heterogeneity, that can make bacteria less susceptible to QACs. To facilitate studies on resistance mechanisms towards QACs, we synthesized a fluorescent quaternary ammonium compound, namely N-dodecyl-N,N-dimethyl-[2-[(4-nitro-2,1,3-benzoxadiazol-7-yl)amino]ethyl]azanium-iodide (NBD-DDA). NBD-DDA is readily detected by flow cytometry and fluorescence microscopy with standard GFP/FITC-settings, making it suitable for molecular and single-cell studies. As a proof-of-concept, NBD-DDA was then used to investigate resistance mechanisms which can be heterogeneous among individual bacterial cells. Our results reveal that the antimicrobial activity of NBD-DDA against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa is comparable to that of benzalkonium chloride (BAC), a widely used QAC, and benzyl-dimethyl-dodecylammonium chloride (BAC12), a mono-constituent BAC with alkyl-chain length of 12 and high structural similarity to NBD-DDA. Characteristic time-kill kinetics and increased tolerance of a BAC tolerant E. coli strain against NBD-DDA suggest that the mode of action of NBD-DDA is similar to that of BAC. As revealed by confocal laser scanning microscopy (CLSM), NBD-DDA is preferentially localized to the cell envelope of E. coli, which is a primary target of BAC and other QACs. Leveraging these findings and NBD-DDA's fluorescent properties, we show that reduced cellular accumulation is responsible for the evolved BAC tolerance in the BAC tolerant E. coli strain and that NBD-DDA is subject to efflux mediated by TolC. Overall, NBD-DDA's antimicrobial activity, its fluorescent properties, and its ease of detection render it a powerful tool to study resistance mechanisms of QACs in bacteria and highlight its potential to gain detailed insights into its mode-of-action.
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Affiliation(s)
- Niclas Nordholt
- Division of Biodeterioration and Reference Organisms (4.1), Department of Materials and the Environment, Federal Institute for Materials Research and Testing (BAM), Berlin, Germany
| | - Kate O'Hara
- Division of Biodeterioration and Reference Organisms (4.1), Department of Materials and the Environment, Federal Institute for Materials Research and Testing (BAM), Berlin, Germany,Division of Biophotonics (1.2), Department of Analytical Chemistry, Reference Materials, Federal Institute for Materials Research and Testing (BAM), Berlin, Germany
| | - Ute Resch-Genger
- Division of Biophotonics (1.2), Department of Analytical Chemistry, Reference Materials, Federal Institute for Materials Research and Testing (BAM), Berlin, Germany
| | - Mark A. T. Blaskovich
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Bastian Rühle
- Division of Biophotonics (1.2), Department of Analytical Chemistry, Reference Materials, Federal Institute for Materials Research and Testing (BAM), Berlin, Germany
| | - Frank Schreiber
- Division of Biodeterioration and Reference Organisms (4.1), Department of Materials and the Environment, Federal Institute for Materials Research and Testing (BAM), Berlin, Germany,*Correspondence: Frank Schreiber,
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7
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Morstein J, Capecchi A, Hinnah K, Park B, Petit-Jacques J, Van Lehn RC, Reymond JL, Trauner D. Medium-Chain Lipid Conjugation Facilitates Cell-Permeability and Bioactivity. J Am Chem Soc 2022; 144:18532-18544. [PMID: 36178375 DOI: 10.1021/jacs.2c07833] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The majority of bioactive molecules act on membrane proteins or intracellular targets and therefore needs to partition into or cross biological membranes. Natural products often exhibit lipid modifications to facilitate critical molecule-membrane interactions, and in many cases their bioactivity is markedly reduced upon removal of a lipid group. However, despite its importance in nature, lipid-conjugation of small molecules is not commonly used in chemical biology and medicinal chemistry, and the effect of such conjugation has not been systematically studied. To understand the composition of lipids found in natural products, we carried out a chemoinformatic characterization of the "natural product lipidome". According to this analysis, lipidated natural products predominantly contain saturated medium-chain lipids (MCLs), which are significantly shorter than the long-chain lipids (LCLs) found in membranes and lipidated proteins. To study the usefulness of such modifications in probe design, we systematically explored the effect of lipid conjugation on five different small molecule chemotypes and find that permeability, cellular retention, subcellular localization, and bioactivity can be significantly modulated depending on the type of lipid tail used. We demonstrate that MCL conjugation can render molecules cell-permeable and modulate their bioactivity. With all explored chemotypes, MCL-conjugates consistently exhibited superior uptake or bioactivity compared to LCL-conjugates and either comparable or superior uptake or bioactivity to short-chain lipid (SCL)-conjugates. Together, our findings suggest that conjugation of small molecules with MCLs could be a powerful strategy for the design of probes and drugs.
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Affiliation(s)
- Johannes Morstein
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, California 94158, United States
- Department of Chemistry, New York University, New York, New York 10003, United States
| | - Alice Capecchi
- Department of Chemistry, Biochemistry, and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Konstantin Hinnah
- Department of Chemical Biology, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - ByungUk Park
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Jerome Petit-Jacques
- Ion Lab, NYU School of Medicine, 435 East 30th Street, New York, New York 10016, United States
| | - Reid C Van Lehn
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Jean-Louis Reymond
- Department of Chemistry, Biochemistry, and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Dirk Trauner
- Department of Chemistry, New York University, New York, New York 10003, United States
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8
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Lajdova I, Ovsonkova L, Spustova V, Oksa A, Chorvat D, Mateasik A, Marcek Chorvatova A. Spectrally and Time-Resolved Fluorescence Imaging of 22-NBD-Cholesterol in Human Peripheral Blood Mononuclear Cells in Chronic Kidney Disease Patients. Molecules 2021; 26:molecules26226800. [PMID: 34833892 PMCID: PMC8619048 DOI: 10.3390/molecules26226800] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 11/05/2021] [Accepted: 11/08/2021] [Indexed: 11/16/2022] Open
Abstract
The interaction of the fluorescent probe 22-NBD-cholesterol with membranes of human peripheral blood mononuclear cells (PBMC) was tested by time- and spectrally resolved fluorescence imaging to monitor the disturbance of lipid metabolism in chronic kidney disease (CKD) and its treatment with statins. Blood samples from healthy volunteers (HV) and CKD patients, either treated or untreated with statins, were compared. Spectral imaging was done using confocal microscopy at 16 spectral channels in response to 458 nm excitation. Time-resolved imaging was achieved by time-correlated single photon counting (TCSPC) following excitation at 475 nm. The fluorescence of 22-NBD-cholesterol was mostly integrated into plasmatic membrane and/or intracellular membrane but was missing from the nuclear region. The presence of two distinct spectral forms of 22-NBD-cholesterol was uncovered, with significant variations between studied groups. In addition, two fluorescence lifetime components were unmasked, changing in CKD patients treated with statins. The gathered results indicate that 22-NBD-cholesterol may serve as a tool to study changes in the lipid metabolism of patients with CKD to monitor the effect of statin treatment.
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Affiliation(s)
- Ingrid Lajdova
- Department of Clinical and Experimental Pharmacology, Faculty of Medicine, Slovak Medical University, 83303 Bratislava, Slovakia; (I.L.); (V.S.); (A.O.)
| | - Livia Ovsonkova
- Department of Biophotonics, International Laser Centre of the Slovak Centre of Scientific and Technical Information, 84104 Bratislava, Slovakia; (L.O.); (D.C.); (A.M.)
- Department of Biophysics, Faculty of Natural Sciences, University of Ss. Cyril and Methodius, 91701 Trnava, Slovakia
| | - Viera Spustova
- Department of Clinical and Experimental Pharmacology, Faculty of Medicine, Slovak Medical University, 83303 Bratislava, Slovakia; (I.L.); (V.S.); (A.O.)
| | - Adrian Oksa
- Department of Clinical and Experimental Pharmacology, Faculty of Medicine, Slovak Medical University, 83303 Bratislava, Slovakia; (I.L.); (V.S.); (A.O.)
| | - Dusan Chorvat
- Department of Biophotonics, International Laser Centre of the Slovak Centre of Scientific and Technical Information, 84104 Bratislava, Slovakia; (L.O.); (D.C.); (A.M.)
| | - Anton Mateasik
- Department of Biophotonics, International Laser Centre of the Slovak Centre of Scientific and Technical Information, 84104 Bratislava, Slovakia; (L.O.); (D.C.); (A.M.)
| | - Alzbeta Marcek Chorvatova
- Department of Biophotonics, International Laser Centre of the Slovak Centre of Scientific and Technical Information, 84104 Bratislava, Slovakia; (L.O.); (D.C.); (A.M.)
- Department of Biophysics, Faculty of Natural Sciences, University of Ss. Cyril and Methodius, 91701 Trnava, Slovakia
- Correspondence: ; Tel.: +421-2-65421575
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9
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Abe M, Makino A, Murate M, Hullin-Matsuda F, Yanagawa M, Sako Y, Kobayashi T. PMP2/FABP8 induces PI(4,5)P 2-dependent transbilayer reorganization of sphingomyelin in the plasma membrane. Cell Rep 2021; 37:109935. [PMID: 34758297 DOI: 10.1016/j.celrep.2021.109935] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 08/20/2021] [Accepted: 10/13/2021] [Indexed: 12/11/2022] Open
Abstract
Sphingomyelin (SM) is a mammalian lipid mainly distributed in the outer leaflet of the plasma membrane (PM). We show that peripheral myelin protein 2 (PMP2), a member of the fatty-acid-binding protein (FABP) family, can localize at the PM and controls the transbilayer distribution of SM. Genetic screening with genome-wide small hairpin RNA libraries identifies PMP2 as a protein involved in the transbilayer movement of SM. A biochemical assay demonstrates that PMP2 is a phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2)-binding protein. PMP2 induces the tubulation of model membranes in a PI(4,5)P2-dependent manner, accompanied by the modification of the transbilayer membrane distribution of lipids. In the PM of PMP2-overexpressing cells, inner-leaflet SM is increased whereas outer-leaflet SM is reduced. PMP2 is a causative protein of Charcot-Marie-Tooth disease (CMT). A mutation in PMP2 associated with CMT increases its affinity for PI(4,5)P2, inducing membrane tubulation and the subsequent transbilayer movement of lipids.
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Affiliation(s)
- Mitsuhiro Abe
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.
| | - Asami Makino
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Motohide Murate
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, 67401 Illkirch, France
| | - Françoise Hullin-Matsuda
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Université de Lyon, CarMeN Laboratory, INSERM U1060, INRAE U1397, Université Claude Bernard Lyon 1, 69495 Pierre-Benite, France
| | - Masataka Yanagawa
- Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Yasushi Sako
- Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Toshihide Kobayashi
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, 67401 Illkirch, France.
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10
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Rajan S, de Guzman HC, Palaia T, Goldberg IJ, Hussain MM. A simple, rapid, and sensitive fluorescence-based method to assess triacylglycerol hydrolase activity. J Lipid Res 2021; 62:100115. [PMID: 34508728 PMCID: PMC8488599 DOI: 10.1016/j.jlr.2021.100115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 08/26/2021] [Accepted: 08/30/2021] [Indexed: 01/22/2023] Open
Abstract
Lipases constitute an important class of water-soluble enzymes that catalyze the hydrolysis of hydrophobic triacylglycerol (TAG). Their enzymatic activity is typically measured using multistep procedures involving isolation and quantification of the hydrolyzed products. We report here a new fluorescence method to measure lipase activity in real time that does not require the separation of substrates from products. We developed this method using adipose triglyceride lipase (ATGL) and lipoprotein lipase (LpL) as model lipases. We first incubated a source of ATGL or LpL with substrate vesicles containing nitrobenzoxadiazole (NBD)-labeled TAG, then measured increases in NBD fluorescence, and calculated enzyme activities. Incorporation of NBD-TAG into phosphatidylcholine (PC) vesicles resulted in some hydrolysis; however, incorporation of phosphatidylinositol into these NBD-TAG/PC vesicles and increasing the ratio of NBD-TAG to PC greatly enhanced substrate hydrolysis. This assay was also useful in measuring the activity of pancreatic lipase and hormone-sensitive lipase. Next, we tested several small-molecule lipase inhibitors and found that orlistat inhibits all lipases, indicating that it is a pan-lipase inhibitor. In short, we describe a simple, rapid, fluorescence-based triacylglycerol hydrolysis assay to assess four major TAG hydrolases: intracellular ATGL and hormone-sensitive lipase, LpL localized at the extracellular endothelium, and pancreatic lipase present in the intestinal lumen. The major advantages of this method are its speed, simplicity, and elimination of product isolation. This assay is potentially applicable to a wide range of lipases, is amenable to high-throughput screening to discover novel modulators of triacylglycerol hydrolases, and can be used for diagnostic purposes.
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Affiliation(s)
- Sujith Rajan
- Department of Foundations of Medicine, NYU Long Island School of Medicine, and Diabetes and Obesity Research Center, NYU Langone Hospitals - Long Island, Mineola, NY, USA
| | - Hazel C de Guzman
- Department of Foundations of Medicine, NYU Long Island School of Medicine, and Diabetes and Obesity Research Center, NYU Langone Hospitals - Long Island, Mineola, NY, USA; Department of Environmental Medicine, NYU Grossman School of Medicine, New York, NY, USA
| | - Thomas Palaia
- Department of Foundations of Medicine, NYU Long Island School of Medicine, and Diabetes and Obesity Research Center, NYU Langone Hospitals - Long Island, Mineola, NY, USA
| | - Ira J Goldberg
- Division of Endocrinology, Department of Medicine, NYU Grossman School of Medicine, New York, NY, USA
| | - M Mahmood Hussain
- Department of Foundations of Medicine, NYU Long Island School of Medicine, and Diabetes and Obesity Research Center, NYU Langone Hospitals - Long Island, Mineola, NY, USA; VA New York Harbor Healthcare System, Brooklyn, NY, USA.
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11
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Chattopadhyay A, Biswas SC, Rukmini R, Saha S, Samanta A. Lack of Environmental Sensitivity of a Naturally Occurring Fluorescent Analog of Cholesterol. J Fluoresc 2021; 31:1401-1407. [PMID: 34224042 DOI: 10.1007/s10895-021-02767-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/01/2021] [Indexed: 11/26/2022]
Abstract
Dehydroergosterol (DHE, Δ5,7,9(11),22-ergostatetraen-3β-ol) is a naturally occurring fluorescent analog of cholesterol found in yeast. Since DHE has been shown to faithfully mimic cholesterol in a large number of biophysical, biochemical, and cell biological studies, it is widely used to explore cholesterol organization, dynamics and trafficking in model and biological membranes. In this work, we show that DHE, in spite of its localization at the membrane interface, does not exhibit red edge excitation shift (REES) in model membranes, irrespective of the membrane phase. These results are reinforced by semi-empirical quantum chemical calculations of dipole moment changes of DHE in ground and excited states, which show a very small change in the dipole moment of DHE upon excitation. We conclude that DHE fluorescence exhibits lack of environmental sensitivity, despite its usefulness in monitoring cholesterol organization, dynamics and traffic in model and biological membranes.
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Affiliation(s)
| | - Samares C Biswas
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500 007, India
| | - Raju Rukmini
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500 007, India
| | - Satyen Saha
- School of Chemistry, University of Hyderabad, Hyderabad, 500 046, India
- Department of Chemistry, Banaras Hindu University, Varanasi, 221 005, India
| | - Anunay Samanta
- School of Chemistry, University of Hyderabad, Hyderabad, 500 046, India
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12
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Fraix A, Parisi C, Seggio M, Sortino S. Nitric Oxide Photoreleasers with Fluorescent Reporting. Chemistry 2021; 27:12714-12725. [PMID: 34143909 DOI: 10.1002/chem.202101662] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Indexed: 01/07/2023]
Abstract
Nitric oxide (NO) plays a multifaceted role in human physiology and pathophysiology, and its controlled delivery has great prospects in therapeutic applications. The light-activated uncaging of NO from NO caging compounds allows this free radical to be released with accurate control of site and dosage, which strictly determine its biological effects. Molecular constructs able to activate fluorescence concomitantly to NO release offer the important advantage of easy and real-time tracking of the amount of NO uncaged in a non-invasive fashion even in the cell environment. This contribution provides an overview of the advances in photoactivatable NO releasers bearing fluorescent reporting functionalities achieved in our and other laboratories, highlighting the rationale design and their potential therapeutic applications.
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Affiliation(s)
- Aurore Fraix
- PhotoChemLab, Department of Drug and Health Sciences, University of Catania, 95125, Catania, Italy
| | - Cristina Parisi
- PhotoChemLab, Department of Drug and Health Sciences, University of Catania, 95125, Catania, Italy
| | - Mimimorena Seggio
- PhotoChemLab, Department of Drug and Health Sciences, University of Catania, 95125, Catania, Italy
| | - Salvatore Sortino
- PhotoChemLab, Department of Drug and Health Sciences, University of Catania, 95125, Catania, Italy
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13
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Pal S, Chakraborty H, Chattopadhyay A. Lipid Headgroup Charge Controls Melittin Oligomerization in Membranes: Implications in Membrane Lysis. J Phys Chem B 2021; 125:8450-8459. [PMID: 34254509 DOI: 10.1021/acs.jpcb.1c02499] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Melittin, a hemolytic peptide present in bee venom, represents one of the most well-studied amphipathic antimicrobial peptides, particularly in terms of its membrane interaction and activity. Nevertheless, no consensus exists on the oligomeric state of membrane-bound melittin. We previously reported on the differential microenvironments experienced by melittin in zwitterionic and negatively charged phospholipid membranes. In this work, we explore the role of negatively charged lipids in the oligomerization of membrane-bound melittin (labeled with 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD)) utilizing a quantitative photobleaching homo-FRET assay. Our results show that the presence of negatively charged lipids decreases melittin oligomeric size to ∼50% of that observed in zwitterionic membranes. This is possibly due to differential energetics of binding of the peptide monomer to membranes of different compositions and could explain the reduced lytic activity yet tighter binding of melittin in negatively charged membranes. These results constitute one of the first experimental observations on the role of phospholipid headgroup charge in the oligomerization of melittin in membranes and is relevant in light of previous apparently contradictory reports on oligomerization of membrane-bound melittin. Our results highlight the synergistic interplay of peptide-membrane binding events and peptide oligomerization in modulating the organization, dynamics, and function of amphipathic α-helical peptides.
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Affiliation(s)
- Sreetama Pal
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.,Academy of Scientific and Innovative Research, Ghaziabad 201 002, India.,CSIR-Indian Institute of Chemical Technology, Uppal Road, Hyderabad 500 007, India
| | - Hirak Chakraborty
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.,School of Chemistry, Sambalpur University, Burla, Odisha 768 019, India
| | - Amitabha Chattopadhyay
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.,Academy of Scientific and Innovative Research, Ghaziabad 201 002, India
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14
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Environment-Sensitive Fluorescence of 7-Nitrobenz-2-oxa-1,3-diazol-4-yl (NBD)-Labeled Ligands for Serotonin Receptors. Molecules 2021; 26:molecules26133848. [PMID: 34202630 PMCID: PMC8270269 DOI: 10.3390/molecules26133848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/19/2021] [Accepted: 06/21/2021] [Indexed: 12/21/2022] Open
Abstract
Serotonin is a neurotransmitter that plays a crucial role in the regulation of several behavioral and cognitive functions by binding to a number of different serotonin receptors present on the cell surface. We report here the synthesis and characterization of several novel fluorescent analogs of serotonin in which the fluorescent NBD (7-nitrobenz-2-oxa-1,3-diazol-4-yl) group is covalently attached to serotonin. The fluorescent ligands compete with the serotonin1A receptor specific radiolabeled agonist for binding to the receptor. Interestingly, these fluorescent ligands display a high environmental sensitivity of their fluorescence. Importantly, the human serotonin1A receptor stably expressed in CHO-K1 cells could be specifically labeled with one of the fluorescent ligands with minimal nonspecific labeling. Interestingly, we show by spectral imaging that the NBD-labeled ligand exhibits a red edge excitation shift (REES) of 29 nm when bound to the receptor, implying that it is localized in a restricted microenvironment. Taken together, our results show that NBD-labeled serotonin analogs offer an attractive fluorescent approach for elucidating the molecular environment of the serotonin binding site in serotonin receptors. In view of the multiple roles played by the serotonergic systems in the central and peripheral nervous systems, these fluorescent ligands would be useful in future studies involving serotonin receptors.
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15
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Herschede SR, Gneid H, Dent T, Jaeger EB, Lawson LB, Busschaert N. Bactericidal urea crown ethers target phosphatidylethanolamine membrane lipids. Org Biomol Chem 2021; 19:3838-3843. [PMID: 33949594 DOI: 10.1039/d1ob00263e] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
An increasing number of people are infected with antibiotic-resistant bacteria each year, sometimes with fatal consequences. In this manuscript, we report a novel urea-functionalized crown ether that can bind to the bacterial lipid phosphatidylethanolamine (PE), facilitate PE flip-flop and displays antibacterial activity against the Gram-positive bacterium Bacillus cereus with a minimum inhibitory concentration comparable to that of the known PE-targeting lantibiotic duramycin.
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Affiliation(s)
- Sarah R Herschede
- Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
| | - Hassan Gneid
- Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
| | - Taylor Dent
- Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
| | - Ellen B Jaeger
- Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
| | - Louise B Lawson
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Nathalie Busschaert
- Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
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16
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Kundu R, Chandra A, Datta A. Fluorescent Chemical Tools for Tracking Anionic Phospholipids. Isr J Chem 2021. [DOI: 10.1002/ijch.202100003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Rajasree Kundu
- Department of Chemical Sciences Tata Institute of Fundamental Research 1 Homi Bhabha Road, Colaba Mumbai 400005 India
| | - Amitava Chandra
- Department of Chemical Sciences Tata Institute of Fundamental Research 1 Homi Bhabha Road, Colaba Mumbai 400005 India
| | - Ankona Datta
- Department of Chemical Sciences Tata Institute of Fundamental Research 1 Homi Bhabha Road, Colaba Mumbai 400005 India
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17
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Cholesterol interaction attenuates scramblase activity of SCRM-1 in the artificial membrane. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183548. [PMID: 33417966 DOI: 10.1016/j.bbamem.2020.183548] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 01/09/2023]
Abstract
Phospholipid (PL) scramblases are single-pass transmembrane protein mediating bidirectional PL translocation. Previously in silico analysis of human PL scramblases, predicted the presence of an uncharacterized cholesterol-binding domain spanning partly in the transmembrane helix as well as in the adjacent extracellular coil. This domain was found to be universally conserved in diverse organisms like Caenorhabditis elegans. In this study, we investigated the saturable cholesterol-binding domain of SCRM-1 using fluorescence sterol binding assay, Stern-Volmer quenching, Förster resonance energy transfer, and CD spectroscopy. We observed high-affinity interaction between cholesterol and SCRM-1. Our results support a previous report, which showed that the cholesterol ordering effect reduced the scramblase activity of hPLSCR1. Considering the presence of a high-affinity binding sequence, we propose that the reduction in activity could partly be due to the cholesterol binding. To validate this, we generated a C-terminal helix (CTH) deletion construct (∆CTH SCRM-1) and a point mutation in the putative cholesterol-binding domain I273D SCRM-1. Deletion construct greatly reduced cholesterol affinity along with loss of scramblase activity. In contrast to this, I273D SCRM-1 retained scrambling activity in proteoliposomes containing ~30 mol% cholesterol but lost sterol binding ability. These results suggest that C-terminal helix is crucial for membrane insertion and in the lipid bilayer the scrambling activity of SCRM-1 is modulated through its interaction with cholesterol.
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18
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Moesgaard L, Petersen D, Szomek M, Reinholdt P, Winkler MBL, Frain KM, Müller P, Pedersen BP, Kongsted J, Wüstner D. Mechanistic Insight into Lipid Binding to Yeast Niemann Pick Type C2 Protein. Biochemistry 2020; 59:4407-4420. [PMID: 33141558 DOI: 10.1021/acs.biochem.0c00574] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Niemann Pick type C2 (NPC2) is a small sterol binding protein in the lumen of late endosomes and lysosomes. We showed recently that the yeast homologue of NPC2 together with its binding partner NCR1 mediates integration of ergosterol, the main sterol in yeast, into the vacuolar membrane. Here, we study the binding specificity and the molecular details of lipid binding to yeast NPC2. We find that NPC2 binds fluorescence- and spin-labeled analogues of phosphatidylcholine (PC), phosphatidylserine, phosphatidylinositol (PI), and sphingomyelin. Spectroscopic experiments show that NPC2 binds lipid monomers in solution but can also interact with lipid analogues in membranes. We further identify ergosterol, PC, and PI as endogenous NPC2 ligands. Using molecular dynamics simulations, we show that NPC2's binding pocket can adapt to the ligand shape and closes around bound ergosterol. Hydrophobic interactions stabilize the binding of ergosterol, but binding of phospholipids is additionally stabilized by electrostatic interactions at the mouth of the binding site. Our work identifies key residues that are important in stabilizing the binding of a phospholipid to yeast NPC2, thereby rationalizing future mutagenesis studies. Our results suggest that yeast NPC2 functions as a general "lipid solubilizer" and binds a variety of amphiphilic lipid ligands, possibly to prevent lipid micelle formation inside the vacuole.
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Affiliation(s)
- Laust Moesgaard
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Daniel Petersen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Maria Szomek
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Peter Reinholdt
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Mikael B L Winkler
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, Aarhus C 8000, Denmark
| | - Kelly May Frain
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, Aarhus C 8000, Denmark
| | - Peter Müller
- Department of Biology, Humboldt University Berlin, Unter den Linden 6, 10099 Berlin, Germany
| | - Bjørn Panyella Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, Aarhus C 8000, Denmark
| | - Jacob Kongsted
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Daniel Wüstner
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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19
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Li Q, Jaiswal M, Rohokale RS, Guo Z. A Diversity-Oriented Strategy for Chemoenzymatic Synthesis of Glycosphingolipids and Related Derivatives. Org Lett 2020; 22:8245-8249. [PMID: 33074681 DOI: 10.1021/acs.orglett.0c02847] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A diversity-oriented strategy combining enzymatic glycan assembly and on-site lipid remodeling via chemoselective cross-metathesis and N-acylation was developed for glycosphingolipid (GSL) synthesis starting from a common, simple glycoside. The strategy was verified with a series of natural GSLs and GSL derivatives and showed several advantages. Most notably, it enabled two-way diversification of the glycan and lipid, including introduction of designed molecular tags, to provide functionalized GSLs useful for biological studies and applications.
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Affiliation(s)
- Qingjiang Li
- Department of Chemistry, University of Florida, 214 Leigh Hall, Gainesville, Florida 32611, United States
| | - Mohit Jaiswal
- Department of Chemistry, University of Florida, 214 Leigh Hall, Gainesville, Florida 32611, United States
| | - Rajendra S Rohokale
- Department of Chemistry, University of Florida, 214 Leigh Hall, Gainesville, Florida 32611, United States
| | - Zhongwu Guo
- Department of Chemistry, University of Florida, 214 Leigh Hall, Gainesville, Florida 32611, United States
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20
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Höger GA, Wiegand M, Worbs B, Diederichsen U. Membrane-Associated Nucleobase-Functionalized β-Peptides (β-PNAs) Affecting Membrane Support and Lipid Composition. Chembiochem 2020; 21:2599-2603. [PMID: 32346953 PMCID: PMC7540700 DOI: 10.1002/cbic.202000172] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/26/2020] [Indexed: 11/18/2022]
Abstract
Protein-membrane interactions are essential to maintain membrane integrity and control membrane morphology and composition. Cytoskeletal proteins in particular are known to interact to a high degree with lipid bilayers and to line the cytoplasmic side of the plasma membrane with an extensive network structure. In order to gain a better mechanistical understanding of the protein-membrane interplay and possible membrane signaling, we started to develop a model system based on β-peptide nucleic acids (β-PNAs). These β-peptides are known to form stable hydrogen-bonded aggregates due to their helical secondary structure, which serve to pre-organize the attached nucleobases. After optimization of the β-PNA solid-phase peptide synthesis and validation of helix formation, the ability of the novel β-PNAs to dimerize and interact with lipid bilayers was investigated by both fluorescence and circular dichroism spectroscopy. It was shown that duplex formation occurs rapidly and with high specificity and could also be detected on the surfaces of the lipid bilayers. Hereby, the potential of a β-PNA-based peptide system to mimic membrane-associated protein networks could be demonstrated.
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Affiliation(s)
- Geralin A. Höger
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTammannstraße 237077GöttingenGermany
| | - Markus Wiegand
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTammannstraße 237077GöttingenGermany
| | - Brigitte Worbs
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTammannstraße 237077GöttingenGermany
| | - Ulf Diederichsen
- Institut für Organische und Biomolekulare ChemieGeorg-August-Universität GöttingenTammannstraße 237077GöttingenGermany
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21
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Filipe HAL, Moreno MJ, Loura LMS. The Secret Lives of Fluorescent Membrane Probes as Revealed by Molecular Dynamics Simulations. Molecules 2020; 25:E3424. [PMID: 32731549 PMCID: PMC7435664 DOI: 10.3390/molecules25153424] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/23/2020] [Accepted: 07/25/2020] [Indexed: 12/15/2022] Open
Abstract
Fluorescent probes have been employed for more than half a century to study the structure and dynamics of model and biological membranes, using spectroscopic and/or microscopic experimental approaches. While their utilization has led to tremendous progress in our knowledge of membrane biophysics and physiology, in some respects the behavior of bilayer-inserted membrane probes has long remained inscrutable. The location, orientation and interaction of fluorophores with lipid and/or water molecules are often not well known, and they are crucial for understanding what the probe is actually reporting. Moreover, because the probe is an extraneous inclusion, it may perturb the properties of the host membrane system, altering the very properties it is supposed to measure. For these reasons, the need for independent methodologies to assess the behavior of bilayer-inserted fluorescence probes has been recognized for a long time. Because of recent improvements in computational tools, molecular dynamics (MD) simulations have become a popular means of obtaining this important information. The present review addresses MD studies of all major classes of fluorescent membrane probes, focusing in the period between 2011 and 2020, during which such work has undergone a dramatic surge in both the number of studies and the variety of probes and properties accessed.
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Affiliation(s)
- Hugo A. L. Filipe
- Chemistry Department, Coimbra Chemistry Center, Faculty of Sciences and Technology, University of Coimbra, 3004-535 Coimbra, Portugal;
| | - Maria João Moreno
- Coimbra Chemistry Center and CNC—Center for Neuroscience and Cell Biology, Chemistry Department, Faculty of Sciences and Technology, University of Coimbra, 3004-535 Coimbra, Portugal;
| | - Luís M. S. Loura
- Coimbra Chemistry Center and CNC—Center for Neuroscience and Cell Biology, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
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22
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Picca G, Probst M, Langenegger SM, Khorev O, Bütikofer P, Menon AK, Häner R. Nonenzymatic synthesis of anomerically pure, mannosyl-based molecular probes for scramblase identification studies. Beilstein J Org Chem 2020; 16:1732-1739. [PMID: 32765793 PMCID: PMC7385334 DOI: 10.3762/bjoc.16.145] [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: 05/05/2020] [Accepted: 07/09/2020] [Indexed: 11/23/2022] Open
Abstract
The chemical synthesis of molecular probes to identify and study membrane proteins involved in the biological pathway of protein glycosylation is described. Two short-chain glycolipid analogs that mimic the naturally occurring substrate mannosyl phosphoryl dolichol exhibit either photoreactive and clickable properties or allow the use of a fluorescence readout. Both probes consist of a hydrophilic mannose headgroup that is linked to a citronellol derivative via a phosphodiester bridge. Moreover, a novel phosphoramidite chemistry-based method offers a straightforward approach for the non-enzymatic incorporation of the saccharide moiety in an anomerically pure form.
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Affiliation(s)
- Giovanni Picca
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Markus Probst
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Simon M Langenegger
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Oleg Khorev
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Peter Bütikofer
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland
| | - Anant K Menon
- Department of Biochemistry, Weill Cornell Medical College, 1300 York Avenue, 10065 New York, United States of America
| | - Robert Häner
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
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23
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Parisi C, Seggio M, Fraix A, Sortino S. A High‐Performing Metal‐Free Photoactivatable Nitric Oxide Donor with a Green Fluorescent Reporter. CHEMPHOTOCHEM 2020. [DOI: 10.1002/cptc.202000100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Cristina Parisi
- PhotoChemLabDepartment of Drug SciencesUniversity of Catania I-95125 Catania Italy
| | - Mimimorena Seggio
- PhotoChemLabDepartment of Drug SciencesUniversity of Catania I-95125 Catania Italy
| | - Aurore Fraix
- PhotoChemLabDepartment of Drug SciencesUniversity of Catania I-95125 Catania Italy
| | - Salvatore Sortino
- PhotoChemLabDepartment of Drug SciencesUniversity of Catania I-95125 Catania Italy
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24
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Wenskowsky L, Wagner M, Reusch J, Schreuder H, Matter H, Opatz T, Petry SM. Resolving Binding Events on the Multifunctional Human Serum Albumin. ChemMedChem 2020; 15:738-743. [PMID: 32162429 PMCID: PMC7318646 DOI: 10.1002/cmdc.202000069] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 02/25/2020] [Indexed: 12/29/2022]
Abstract
Physiological processes rely on initial recognition events between cellular components and other molecules or modalities. Biomolecules can have multiple sites or mode of interaction with other molecular entities, so that a resolution of the individual binding events in terms of spatial localization as well as association and dissociation kinetics is required for a meaningful description. Here we describe a trichromatic fluorescent binding- and displacement assay for simultaneous monitoring of three individual binding sites in the important transporter and binding protein human serum albumin. Independent investigations of binding events by X-ray crystallography and time-resolved dynamics measurements (switchSENSE technology) confirm the validity of the assay, the localization of binding sites and furthermore reveal conformational changes associated with ligand binding. The described assay system allows for the detailed characterization of albumin-binding drugs and is therefore well-suited for prediction of drug-drug and drug-food interactions. Moreover, conformational changes, usually associated with binding events, can also be analyzed.
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Affiliation(s)
- Lea Wenskowsky
- Institute of Organic ChemistryJohannes Gutenberg-UniversityDuesbergweg 10–1455128MainzGermany
| | - Michael Wagner
- Sanofi-Aventis Deutschland GmbHIndustriepark Höchst65926Frankfurt am MainGermany
| | - Johannes Reusch
- Dynamic Biosensors GmbHLochhamer Straße 1582152Martinsried/PlaneggGermany
| | - Herman Schreuder
- Sanofi-Aventis Deutschland GmbHIndustriepark Höchst65926Frankfurt am MainGermany
| | - Hans Matter
- Sanofi-Aventis Deutschland GmbHIndustriepark Höchst65926Frankfurt am MainGermany
| | - Till Opatz
- Institute of Organic ChemistryJohannes Gutenberg-UniversityDuesbergweg 10–1455128MainzGermany
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25
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Dutta T, Pal K, Koner AL. Cellular metabolic activity marker via selective turn-ON detection of transporter protein using nitrobenzoxadiazole-based fluorescent reporter. Sci Rep 2020; 10:4166. [PMID: 32139799 PMCID: PMC7058046 DOI: 10.1038/s41598-020-60954-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 02/05/2020] [Indexed: 01/21/2023] Open
Abstract
A nitrobenzoxadiazole-based fluoroprobe (NBD-Bu) is designed to probe cellular metabolic activity in cancer and normal cells. NBD-Bu shows a significant fluorescence enhancement upon selective binding to the transport protein serum albumin in PBS buffer at ambient conditions. Encouraged by this finding, the site- specificity of NBD-Bu has been explored through a competitive displacement assay in the presence of site-specific markers such as warfarin and ibuprofen. Notably, even at micromolar concentrations, the probe possesses the ability to displace the site marker drug ibuprofen, efficiently. Subsequently, high-resolution fluorescence imaging results consolidated the potential of NBD-Bu for detection of abnormal cellular metabolic activity.
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Affiliation(s)
- Tanoy Dutta
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, 462066, (MP), India
| | - Kaushik Pal
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, 462066, (MP), India
- Department of Physics and Astronomy, Iowa State University, lowa, IA, 50011, USA
| | - Apurba L Koner
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, 462066, (MP), India.
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26
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Tornmalm J, Piguet J, Chmyrov V, Widengren J. Imaging of intermittent lipid-receptor interactions reflects changes in live cell membranes upon agonist-receptor binding. Sci Rep 2019; 9:18133. [PMID: 31792325 PMCID: PMC6889430 DOI: 10.1038/s41598-019-54625-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 11/11/2019] [Indexed: 12/26/2022] Open
Abstract
Protein-lipid interactions in cellular membranes modulate central cellular functions, are often transient in character, but occur too intermittently to be readily observable. We introduce transient state imaging (TRAST), combining sensitive fluorescence detection of fluorophore markers with monitoring of their dark triplet state transitions, allowing imaging of such protein-lipid interactions. We first determined the dark state kinetics of the biomembrane fluorophore 7-nitrobenz-2-oxa-1,3-diazole-4-yl (NBD) in lipid vesicles, and how its triplet state is quenched by spin-labels in the same membranes. We then monitored collisional quenching of NBD-lipid derivatives by spin-labelled stearic acids in live cell plasma membranes, and of NBD-lipid derivatives by spin-labelled G-Protein Coupled Receptors (GPCRs). We could then resolve transient interactions between the GPCRs and different lipids, how these interactions changed upon GPCR activation, thereby demonstrating a widely applicable means to image and characterize transient molecular interactions in live cell membranes in general, not within reach via traditional fluorescence readouts.
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Affiliation(s)
- Johan Tornmalm
- Experimental Biomolecular Physics, KTH, 10691, Stockholm, Sweden
| | - Joachim Piguet
- Experimental Biomolecular Physics, KTH, 10691, Stockholm, Sweden.
| | | | - Jerker Widengren
- Experimental Biomolecular Physics, KTH, 10691, Stockholm, Sweden.
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27
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Marquezin CA, Ito AS, de Souza ES. Organization and dynamics of NBD-labeled lipids in lipid bilayer analyzed by FRET using the small membrane fluorescent probe AHBA as donor. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:182995. [DOI: 10.1016/j.bbamem.2019.05.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 05/13/2019] [Accepted: 05/23/2019] [Indexed: 01/22/2023]
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28
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Raghuraman H, Chatterjee S, Das A. Site-Directed Fluorescence Approaches for Dynamic Structural Biology of Membrane Peptides and Proteins. Front Mol Biosci 2019; 6:96. [PMID: 31608290 PMCID: PMC6774292 DOI: 10.3389/fmolb.2019.00096] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 09/11/2019] [Indexed: 12/31/2022] Open
Abstract
Membrane proteins mediate a number of cellular functions and are associated with several diseases and also play a crucial role in pathogenicity. Due to their importance in cellular structure and function, they are important drug targets for ~60% of drugs available in the market. Despite the technological advancement and recent successful outcomes in determining the high-resolution structural snapshot of membrane proteins, the mechanistic details underlining the complex functionalities of membrane proteins is least understood. This is largely due to lack of structural dynamics information pertaining to different functional states of membrane proteins in a membrane environment. Fluorescence spectroscopy is a widely used technique in the analysis of functionally-relevant structure and dynamics of membrane protein. This review is focused on various site-directed fluorescence (SDFL) approaches and their applications to explore structural information, conformational changes, hydration dynamics, and lipid-protein interactions of important classes of membrane proteins that include the pore-forming peptides/proteins, ion channels/transporters and G-protein coupled receptors.
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Affiliation(s)
- H. Raghuraman
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, Homi Bhabha National Institute, Kolkata, India
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29
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Engberg O, Scheidt HA, Nyholm TKM, Slotte JP, Huster D. Membrane Localization and Lipid Interactions of Common Lipid-Conjugated Fluorescence Probes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:11902-11911. [PMID: 31424941 DOI: 10.1021/acs.langmuir.9b01202] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Lateral segregation of lipids in model and biological membranes has been studied intensively in the last decades using a comprehensive set of experimental techniques. Most methods require a probe to report on the biophysical properties of a specific molecule in the lipid bilayer. Because such probes can adversely affect the results of the measurement and perturb the local membrane structure and dynamics, a detailed understanding of probe behavior and its influence on the properties of its direct environment is important. Membrane phase-selective and lipid-mimicking molecules represent common types of probes. Here, we have studied how the fluorescent probes trans-parinaric acid (tPA), diphenylhexatriene (DPH), and 1-oleoyl-2-propionyl[DPH]-sn-glycero-3-phosphocholine (O-DPH-PC) affect the membrane properties of 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) bilayers using 2H and 31P NMR spectroscopy in the solid state. In addition, using 2D 1H magic-angle spinning (MAS) nuclear Overhauser enhancement spectroscopy (NOESY) NMR, we have determined the distribution of the probe moieties in the POPC membrane parallel to the membrane normal. We found that the different probes exhibit distinct membrane localizations and distributions, e.g. tPA is located parallel to the membrane normal while DPH predominantly exist in two orientations. Further, tPA was conjugated to sphingomyelin (tPA-SM) as a substitute for the acyl chain in the SM. 1H NOESY NMR was used to probe the interaction of the tPA-SM with cholesterol as dominant in liquid ordered membrane domains in comparison to POPC-cholesterol interaction in membranes composed of ternary lipid mixtures. We could show that tPA-SM exhibited a strong favorable and very temperature-dependent interaction with cholesterol in comparison to POPC. In conclusion, the NMR techniques can explain probe behavior but also be used to measure lipid-specific affinities between different lipid segments and individual molecules in complex bilayers, relevant to understanding nanodomain formation in biological membranes.
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Affiliation(s)
- Oskar Engberg
- Institute for Medical Physics and Biophysics, Medical Department , Leipzig University , Leipzig , Germany
- Biochemistry, Faculty of Science and Engineering , Åbo Akademi University , Turku , Finland
| | - Holger A Scheidt
- Institute for Medical Physics and Biophysics, Medical Department , Leipzig University , Leipzig , Germany
| | - Thomas K M Nyholm
- Biochemistry, Faculty of Science and Engineering , Åbo Akademi University , Turku , Finland
| | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering , Åbo Akademi University , Turku , Finland
| | - Daniel Huster
- Institute for Medical Physics and Biophysics, Medical Department , Leipzig University , Leipzig , Germany
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30
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Filipe HAL, Pokorná Š, Hof M, Amaro M, Loura LMS. Orientation of nitro-group governs the fluorescence lifetime of nitrobenzoxadiazole (NBD)-labeled lipids in lipid bilayers. Phys Chem Chem Phys 2019; 21:1682-1688. [PMID: 30418442 DOI: 10.1039/c8cp06064a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Nitrobenzoxadiazole (NBD) labeled lipids are popular fluorescent probes of membrane structure and dynamics, and have been widely used in both model systems and living cells. Irrespective of attachment to the lipid head group or hydrocarbon chains, the NBD fluorophore generally adopts a transverse bilayer location near the host lipid carbonyl/glycerol moieties. Still, considerable variability is observed in the measured fluorescence lifetimes, indicating that overall fluorophore location is not the determinant of NBD fluorescence properties. Combining fluorescence experiments and molecular dynamics simulations, we show that for two almost identical NBD probes, significant differences in fluorophore orientation and fluorescence lifetime are observed. Integrating these findings with literature data, we demonstrate a correlation between NBD orientation and fluorescence lifetime. The latter is longer when the NBD nitro group is predominantly oriented towards the bilayer interior, compared to probes for which it points to the water medium.
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Affiliation(s)
- Hugo A L Filipe
- Coimbra Chemistry Center, University of Coimbra, P-3004-535 Coimbra, Portugal
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31
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Gironi B, Oliva R, Petraccone L, Paolantoni M, Morresi A, Del Vecchio P, Sassi P. Solvation properties of raft-like model membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:183052. [PMID: 31449802 DOI: 10.1016/j.bbamem.2019.183052] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/25/2019] [Accepted: 08/02/2019] [Indexed: 12/15/2022]
Abstract
Dimethyl sulfoxide (DMSO) is a universal water-soluble solvent widely used in many biotechnological and medical applications, such as cells cryopreservation, and for the treatment of different human diseases (e.g. amyloidosis). Despite the great number of reported studies, the effects of DMSO on the physico-chemical properties of biological membranes are poorly understood. Often, these studies are limited to model membranes composed of phosphatidylcholines (PCs) and cholesterol (Chol). In this work, we explored the effect of DMSO on liposomes composed of the natural egg sphingomyelin (ESM) and Chol as raft-like model membranes. With a multi-technique approach we probe the structure and the thermal stability of ESM/Chol bilayer at different Chol mole fractions. In particular, we investigate the ESM-solvent interactions to clarify the role of DMSO in perturbing the solvating conditions of lipid vesicles and show that the addition of DMSO increases the thermal stability of vesicles. An increase of transition temperature, a decrease of both enthalpy and entropy as well as a decrease of the cooperativity of the gel to liquid phase transition are observed at 0.1 DMSO mole fraction. Fluorescence experiments with the probe Laurdan and FTIR spectra strongly indicate that DMSO exerts a dehydration effect on the membrane. Besides, FTIR measurements with tungsten hexacarbonyl, in combination with fluorescence data of the probe NBD-PE, indicate that DMSO promotes the formation of a highly packed membrane by reducing the thickness of the membrane.
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Affiliation(s)
- Beatrice Gironi
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Rosario Oliva
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 21, 80126 Napoli, Italy
| | - Luigi Petraccone
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 21, 80126 Napoli, Italy
| | - Marco Paolantoni
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Assunta Morresi
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Pompea Del Vecchio
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 21, 80126 Napoli, Italy.
| | - Paola Sassi
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy; Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN), Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy.
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32
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Westerfield J, Gupta C, Scott HL, Ye Y, Cameron A, Mertz B, Barrera FN. Ions Modulate Key Interactions between pHLIP and Lipid Membranes. Biophys J 2019; 117:920-929. [PMID: 31422821 DOI: 10.1016/j.bpj.2019.07.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 07/05/2019] [Accepted: 07/22/2019] [Indexed: 02/04/2023] Open
Abstract
The pH-low insertion peptide (pHLIP) is used for targeted delivery of drug cargoes to acidic tissues such as tumors. The extracellular acidosis found in solid tumors triggers pHLIP to transition from a membrane-adsorbed state to fold into a transmembrane α-helix. Different factors influence the acidity required for pHLIP to insert into lipid membranes. One of them is the lipid headgroup composition, which defines the electrostatic profile of the membrane. However, the molecular interactions that drive the adsorption of pHLIP to the bilayer surface are poorly understood. In this study, we combine biophysical experiments and all-atom molecular dynamics simulations to understand the role played by electrostatics in the interaction between pHLIP and a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayer. We observed that the solution ionic strength affects the structure of pHLIP at the membrane surface as well as the acidity needed for different steps in the membrane insertion process. In particular, our simulations revealed that an increase in ionic strength affected both pHLIP and the bilayer; the coordination of sodium ions with the C-terminus of pHLIP led to localized changes in helicity, whereas the coordination of sodium ions with the phosphate moiety of the phosphocholine headgroups had a condensing effect on our model bilayer. These results are relevant to our understanding of environmental influences on the ability of pHLIP to adsorb to the cell membrane and are useful in our fundamental understanding of the absorption of pH-responsive peptides and cell-penetrating peptides.
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Affiliation(s)
- Justin Westerfield
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee-Knoxville, Knoxville, Tennessee
| | - Chitrak Gupta
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia
| | - Haden L Scott
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee-Knoxville, Knoxville, Tennessee
| | - Yujie Ye
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee-Knoxville, Knoxville, Tennessee
| | - Alayna Cameron
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee-Knoxville, Knoxville, Tennessee
| | - Blake Mertz
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia; WVU Cancer Institute, West Virginia University, Morgantown, West Virginia.
| | - Francisco N Barrera
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee-Knoxville, Knoxville, Tennessee.
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33
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Scott HL, Heberle FA, Katsaras J, Barrera FN. Phosphatidylserine Asymmetry Promotes the Membrane Insertion of a Transmembrane Helix. Biophys J 2019; 116:1495-1506. [PMID: 30954213 DOI: 10.1016/j.bpj.2019.03.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/13/2019] [Accepted: 03/06/2019] [Indexed: 11/18/2022] Open
Abstract
The plasma membrane (PM) contains an asymmetric distribution of lipids between the inner and outer bilayer leaflets. A lipid of special interest in eukaryotic membranes is the negatively charged phosphatidylserine (PS). In healthy cells, PS is actively sequestered to the inner leaflet of the PM, but PS redistributes to the outer leaflet when the cell is damaged or at the onset of apoptosis. However, the influence of PS asymmetry on membrane protein structure and folding are poorly understood. The pH low insertion peptide (pHLIP) adsorbs to the membrane surface at a neutral pH, but it inserts into the membrane at an acidic pH. We have previously observed that in symmetric vesicles, PS affects the membrane insertion of pHLIP by lowering the pH midpoint of insertion. Here, we studied the effect of PS asymmetry on the membrane interaction of pHLIP. We developed a modified protocol to create asymmetric vesicles containing PS and employed Annexin V labeled with an Alexa Fluor 568 fluorophore as a new probe to quantify PS asymmetry. We observed that the membrane insertion of pHLIP was promoted by the asymmetric distribution of negatively charged PS, which causes a surface charge difference between bilayer leaflets. Our results indicate that lipid asymmetry can modulate the formation of an α-helix on the membrane. A corollary is that model studies using symmetric bilayers to mimic the PM may fail to capture important aspects of protein-membrane interactions.
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Affiliation(s)
- Haden L Scott
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Frederick A Heberle
- The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee; Shull Wollan Center-a Joint Institute for Neutron Sciences, Oak Ridge, Tennessee
| | - John Katsaras
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee; Shull Wollan Center-a Joint Institute for Neutron Sciences, Oak Ridge, Tennessee; Large Scale Structures Group, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee; Department of Physics, Brock University, St. Catharines, Ontario, Canada
| | - Francisco N Barrera
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee.
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34
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Kopečná M, Kováčik A, Kučera O, Macháček M, Sochorová M, Audrlická P, Vávrová K. Fluorescent Penetration Enhancers Reveal Complex Interactions among the Enhancer, Drug, Solvent, and Skin. Mol Pharm 2019; 16:886-897. [DOI: 10.1021/acs.molpharmaceut.8b01196] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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35
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Hickey SM, Ashton TD, Boer G, Bader CA, Thomas M, Elliott AG, Schmuck C, Yu HY, Li J, Nation RL, Cooper MA, Plush SE, Brooks DA, Pfeffer FM. Norbornane-based cationic antimicrobial peptidomimetics targeting the bacterial membrane. Eur J Med Chem 2018; 160:9-22. [PMID: 30316060 DOI: 10.1016/j.ejmech.2018.09.072] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 09/14/2018] [Accepted: 09/29/2018] [Indexed: 11/27/2022]
Abstract
The design, synthesis and evaluation of a small series of potent amphiphilic norbornane antibacterial agents has been performed (compound 10 MIC = 0.25 μg/mL against MRSA). Molecular modelling indicates rapid aggregation of this class of antibacterial agent prior to membrane association and insertion. Two fluorescent analogues (compound 29 with 4-amino-naphthalimide and 34 with 4-nitrobenz-2-oxa-1,3-diazole fluorophores) with good activity (MIC = 0.5 μg/mL against MRSA) were also constructed and confocal microscopy studies indicate that the primary site of interaction for this family of compounds is the bacterial membrane.
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Affiliation(s)
- Shane M Hickey
- Cancer Research Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, 5000, Australia.
| | - Trent D Ashton
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia
| | - Gareth Boer
- Centre for Chemistry and Biotechnology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria, 3216, Australia
| | - Christie A Bader
- Cancer Research Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, 5000, Australia
| | - Michael Thomas
- Research School of Chemistry, The Australian National University, Acton, ACT, 2601, Australia
| | - Alysha G Elliott
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Carsten Schmuck
- Institute for Organic Chemistry, University of Duisburg-Essen, 45117, Essen, Germany
| | - Heidi Y Yu
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Science, Royal Parade, Parkville, Victoria, 3052, Australia
| | - Jian Li
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Science, Royal Parade, Parkville, Victoria, 3052, Australia
| | - Roger L Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Science, Royal Parade, Parkville, Victoria, 3052, Australia
| | - Matthew A Cooper
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Sally E Plush
- Cancer Research Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, 5000, Australia
| | - Douglas A Brooks
- Cancer Research Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, 5000, Australia
| | - Frederick M Pfeffer
- Centre for Chemistry and Biotechnology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria, 3216, Australia.
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36
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Schwarzmann G. Labeled gangliosides: their synthesis and use in biological studies. FEBS Lett 2018; 592:3992-4006. [DOI: 10.1002/1873-3468.13239] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 08/31/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Günter Schwarzmann
- LIMES c/o Kekulé‐Institut f. Organische Chemie und Biochemie Rheinische Friedrich‐Wilhelms‐Universität Bonn Germany
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37
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Hunter CD, Guo T, Daskhan G, Richards MR, Cairo CW. Synthetic Strategies for Modified Glycosphingolipids and Their Design as Probes. Chem Rev 2018; 118:8188-8241. [DOI: 10.1021/acs.chemrev.8b00070] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Carmanah D. Hunter
- Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Tianlin Guo
- Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Gour Daskhan
- Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Michele R. Richards
- Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Christopher W. Cairo
- Alberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
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38
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39
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Huang X, Borgström B, Stegmayr J, Abassi Y, Kruszyk M, Leffler H, Persson L, Albinsson S, Massoumi R, Scheblykin IG, Hegardt C, Oredsson S, Strand D. The Molecular Basis for Inhibition of Stemlike Cancer Cells by Salinomycin. ACS CENTRAL SCIENCE 2018; 4:760-767. [PMID: 29974072 PMCID: PMC6026786 DOI: 10.1021/acscentsci.8b00257] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Indexed: 05/13/2023]
Abstract
Tumors are phenotypically heterogeneous and include subpopulations of cancer cells with stemlike properties. The natural product salinomycin, a K+-selective ionophore, was recently found to exert selectivity against such cancer stem cells. This selective effect is thought to be due to inhibition of the Wnt signaling pathway, but the mechanistic basis remains unclear. Here, we develop a functionally competent fluorescent conjugate of salinomycin to investigate the molecular mechanism of this compound. By subcellular imaging, we demonstrate a rapid cellular uptake of the conjugate and accumulation in the endoplasmic reticulum (ER). This localization is connected to induction of Ca2+ release from the ER into the cytosol. Depletion of Ca2+ from the ER induces the unfolded protein response as shown by global mRNA analysis and Western blot analysis of proteins in the pathway. In particular, salinomycin-induced ER Ca2+ depletion up-regulates C/EBP homologous protein (CHOP), which inhibits Wnt signaling by down-regulating β-catenin. The increased cytosolic Ca2+ also activates protein kinase C, which has been shown to inhibit Wnt signaling. These results reveal that salinomycin acts in the ER membrane of breast cancer cells to cause enhanced Ca2+ release into the cytosol, presumably by mediating a counter-flux of K+ ions. The clarified mechanistic picture highlights the importance of ion fluxes in the ER as an entry to inducing phenotypic effects and should facilitate rational development of cancer treatments.
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Affiliation(s)
- Xiaoli Huang
- Department of Biology, Lund University, Sölvegatan 35C, 223 62 Lund, Sweden
| | - Björn Borgström
- Centre for Analysis and Synthesis, Lund University, Box 124, 221 00 Lund, Sweden
| | - John Stegmayr
- Department of Biology, Lund University, Sölvegatan 35C, 223 62 Lund, Sweden
- Department of Laboratory Medicine, Lund University, BMC C12, 221 84 Lund, Sweden
| | - Yasmin Abassi
- Department of Laboratory Medicine, Translational Cancer Research, Lund University, Scheelevägen 8, 223 63 Lund, Sweden
| | - Monika Kruszyk
- Centre for Analysis and Synthesis, Lund University, Box 124, 221 00 Lund, Sweden
| | - Hakon Leffler
- Department of Laboratory Medicine, Lund University, BMC C12, 221 84 Lund, Sweden
| | - Lo Persson
- Department of Experimental Medical Science, Lund University, BMC D12, 221 84 Lund, Sweden
| | - Sebastian Albinsson
- Department of Experimental Medical Science, Lund University, BMC D12, 221 84 Lund, Sweden
| | - Ramin Massoumi
- Department of Laboratory Medicine, Translational Cancer Research, Lund University, Scheelevägen 8, 223 63 Lund, Sweden
| | - Ivan G Scheblykin
- Department of Chemical Physics and NanoLund, Lund University, Box 118, 221 00 Lund, Sweden
| | - Cecilia Hegardt
- Department of Clinical Sciences Lund, Division of Oncology and Pathology, Lund University, Medicon Village, 223 81 Lund, Sweden
| | - Stina Oredsson
- Department of Biology, Lund University, Sölvegatan 35C, 223 62 Lund, Sweden
| | - Daniel Strand
- Centre for Analysis and Synthesis, Lund University, Box 124, 221 00 Lund, Sweden
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40
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Palanirajan SK, Sivagnanam U, Murugan S, Gummadi SN. In vitro reconstitution and biochemical characterization of human phospholipid scramblase 3: phospholipid specificity and metal ion binding studies. Biol Chem 2018; 399:361-374. [DOI: 10.1515/hsz-2017-0309] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 12/14/2017] [Indexed: 01/11/2023]
Abstract
AbstractHuman phospholipid scramblase 3 (hPLSCR3) is a single pass transmembrane protein that plays a vital role in fat metabolism, mitochondrial function, structure, maintenance and apoptosis. The mechanism of action of scramblases remains still unknown, and the role of scramblases in phospholipid translocation is heavily debated. hPLSCR3 is the only member of scramblase family localized to mitochondria and is involved in cardiolipin translocation at the mitochondrial membrane. Direct biochemical evidence of phospholipid translocation by hPLSCR3 is yet to be reported. Functional assay in synthetic proteoliposomes upon Ca2+and Mg2+revealed that, apart from cardiolipin, recombinant hPLSCR3 translocates aminophospholipids such as NBD-PE and NBD-PS but not neutral phospholipids. Point mutation in hPLSCR3 (F258V) resulted in decreased Ca2+binding affinity. Functional assay with F258V-hPLSCR3 led to ~50% loss in scramblase activity in the presence of Ca2+and Mg2+. Metal ion-induced conformational changes were monitored by intrinsic tryptophan fluorescence, circular dichroism, surface hydrophobicity changes and aggregation studies. Our results revealed that Ca2+and Mg2+bind to hPLSCR3 and trigger conformational changes mediated by aggregation. In summary, we suggest that the metal ion-induced conformational change and the aggregation of the protein are essential for the phospholipid translocation by hPLSCR3.
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Parra GG, Ferreira LP, Gonçalves PJ, Sizova SV, Oleinikov VA, Morozov VN, Kuzmin VA, Borissevitch IE. Stimulation of Cysteine-Coated CdSe/ZnS Quantum Dot Luminescence by meso-Tetrakis (p-sulfonato-phenyl) Porphyrin. NANOSCALE RESEARCH LETTERS 2018; 13:40. [PMID: 29404784 PMCID: PMC5799094 DOI: 10.1186/s11671-018-2449-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 01/20/2018] [Indexed: 06/07/2023]
Abstract
Interaction between porphyrins and quantum dots (QD) via energy and/or charge transfer is usually accompanied by reduction of the QD luminescence intensity and lifetime. However, for CdSe/ZnS-Cys QD water solutions, kept at 276 K during 3 months (aged QD), the significant increase in the luminescence intensity at the addition of meso-tetrakis (p-sulfonato-phenyl) porphyrin (TPPS4) has been observed in this study. Aggregation of QD during the storage provokes reduction in the quantum yield and lifetime of their luminescence. Using steady-state and time-resolved fluorescence techniques, we demonstrated that TPPS4 stimulated disaggregation of aged CdSe/ZnS-Cys QD in aqueous solutions, increasing the quantum yield of their luminescence, which finally reached that of the fresh-prepared QD. Disaggregation takes place due to increase in electrostatic repulsion between QD at their binding with negatively charged porphyrin molecules. Binding of just four porphyrin molecules per single QD was sufficient for total QD disaggregation. The analysis of QD luminescence decay curves demonstrated that disaggregation stronger affected the luminescence related with the electron-hole annihilation in the QD shell. The obtained results demonstrate the way to repair aged QD by adding of some molecules or ions to the solutions, stimulating QD disaggregation and restoring their luminescence characteristics, which could be important for QD biomedical applications, such as bioimaging and fluorescence diagnostics. On the other hand, the disaggregation is important for QD applications in biology and medicine since it reduces the size of the particles facilitating their internalization into living cells across the cell membrane.
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Affiliation(s)
- Gustavo G Parra
- Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, 14040-901, Brazil.
- Present Address: MackGraphe, Mackenzie Presbyterian University, São Paulo, SP, 01302-907, Brazil.
| | - Lucimara P Ferreira
- Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, 14040-901, Brazil
| | - Pablo J Gonçalves
- Instituto de Física, Universidade Federal de Goiás, Caixa Postal 131, Goiânia, GO, 74001-970, Brazil
| | - Svetlana V Sizova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 16/10 Miklukho-Maklaya str, Moscow, Russia, 117997
| | - Vladimir A Oleinikov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 16/10 Miklukho-Maklaya str, Moscow, Russia, 117997
| | | | | | - Iouri E Borissevitch
- Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, 14040-901, Brazil
- Instituto de Física, Universidade Federal de Goiás, Caixa Postal 131, Goiânia, GO, 74001-970, Brazil
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Abstract
Labeled gangliosides are invaluable tools to study their transport and metabolism within cells as well as to determine their distribution in membranes, and their interaction with membrane lipids and proteins. Here I describe established procedures to synthesize ganglioside derivatives with a fluorescent tag either attached to its sialooligosaccharide or ceramide portion. These procedures are chosen as to minimize the integrity of the ganglioside molecule and hence, to leave their native skeleton formally intact. The α-position of the stearic acid residue is favorable for the attachment both of hydrophilic and of lipophilic dyes. In some other cases, and starting from lyso-gangliosides, procedures are described by which a fluorescent tag bound to a short acyl chain replaces the native acyl chain of gangliosides.
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Affiliation(s)
- Günter Schwarzmann
- LIMES, c/o Kekulé-Institut f. Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany.
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Korshunova GA, Shishkina AV, Skulachev MV. Design, Synthesis, and Some Aspects of the Biological Activity of Mitochondria-Targeted Antioxidants. BIOCHEMISTRY (MOSCOW) 2017; 82:760-777. [PMID: 28918741 DOI: 10.1134/s0006297917070021] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This review summarizes for the first time data on the design and synthesis of biologically active compounds of a new generation - mitochondria-targeted antioxidants, which are natural (or synthetic) p-benzoquinones conjugated via a lipophilic linker with (triphenyl)phosphonium or ammonium cations with delocalized charge. It also describes the synthesis of mitochondria-targeted antioxidants - uncouplers of oxidative phosphorylation - based on fluorescent dyes.
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Affiliation(s)
- G A Korshunova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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Scott HL, Westerfield JM, Barrera FN. Determination of the Membrane Translocation pK of the pH-Low Insertion Peptide. Biophys J 2017; 113:869-879. [PMID: 28834723 DOI: 10.1016/j.bpj.2017.06.065] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 06/13/2017] [Accepted: 06/28/2017] [Indexed: 01/13/2023] Open
Abstract
The pH-low insertion peptide (pHLIP) is a leading peptide technology to target the extracellular acidosis that characterizes solid tumors. The pHLIP binds to lipid membranes, and responds to acidification by undergoing a coupled folding/membrane insertion process. In the final transmembrane state, the C terminus of pHLIP gets exposed to the cytoplasm of the target cell, providing a means to translocate membrane-impermeable drug cargoes across the plasma membrane of cancer cells. There exists a need to develop improved pHLIP variants to target tumors with greater efficiency. Characterization of such variants typically relies on determining the pK parameter, the pH midpoint of peptide insertion into the lipid bilayer. Here we report that the value of the pK can be strongly dependent on the method used for its determination. Membrane insertion of pHLIP involves at least four intermediate states, which are believed to be linked to the staggered titration of key acidic residues. We propose that some spectroscopic methods are influenced more heavily by specific membrane folding intermediates, and as a result yield different pK values. To address this potential problem, we have devised an assay to independently monitor the environment of the two termini of pHLIP. This approach provides insights into the conformation pHLIP adopts immediately before the establishment of the transmembrane configuration. Additionally, our data indicate that the membrane translocation of the C terminus of pHLIP, the folding step more directly relevant to drug delivery, occurs at more acidic pH values than previously considered. Consequently, such a pK difference could have substantial ramifications for assessing the translocation of drug cargoes conjugated to pHLIP.
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Affiliation(s)
- Haden L Scott
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Justin M Westerfield
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Francisco N Barrera
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee.
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Concilio S, Ferrentino I, Sessa L, Massa A, Iannelli P, Diana R, Panunzi B, Rella A, Piotto S. A novel fluorescent solvatochromic probe for lipid bilayers. Supramol Chem 2017. [DOI: 10.1080/10610278.2017.1372583] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Simona Concilio
- Department of Industrial Engineering, University of Salerno, Fisciano, Italy
| | | | - Lucia Sessa
- Department of Pharmacy, University of Salerno, Fisciano, Italy
| | - Antonio Massa
- Department of Chemistry and Biology, University of Salerno, Fisciano, Italy
| | - Pio Iannelli
- Department of Pharmacy, University of Salerno, Fisciano, Italy
| | - Rosita Diana
- Department of Chemical Science, University of Napoli Federico II, Napoli, Italy
| | - Barbara Panunzi
- Department of Agriculture, University of Napoli Federico II, Portici, Italy
| | - Antonella Rella
- Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Stefano Piotto
- Department of Pharmacy, University of Salerno, Fisciano, Italy
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Mo GCH, Yip CM. Structural templating of J-aggregates: Visualizing bis(monoacylglycero)phosphate domains in live cells. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:1687-1695. [PMID: 28844737 DOI: 10.1016/j.bbapap.2017.07.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 07/13/2017] [Accepted: 07/24/2017] [Indexed: 12/23/2022]
Abstract
Identifying the key structural and dynamical determinants that drive the association of biomolecules, whether in solution, or perhaps more importantly in a membrane environment, has critical implications for our understanding of cellular dynamics, processes, and signaling. With recent advances in high-resolution imaging techniques, from the development of new molecular labels to technical advances in imaging methodologies and platforms, researchers are now reaping the benefits of being able to directly characterize and quantify local dynamics, structures, and conformations in live cells and tissues. These capabilities are providing unique insights into association stoichiometries, interactions, and structures on sub-micron length scales. We previously examined the role of lipid headgroup chemistry and phase state in guiding the formation of pseudoisocyanine (PIC) dye J-aggregates on supported planar bilayers [Langmuir, 25, 10719]. We describe here how these same J-aggregates can report on the in situ formation of organellar membrane domains in live cells. Live cell hyperspectral confocal microscopy using GFP-conjugated GTPase markers of early (Rab5) and late (Rab7) endosomes revealed that the PIC J-aggregates were confined to domains on either the limiting membrane or intralumenal vesicles (ILV) of late endosomes, known to be enriched in the anionic lipid bis(monoacylglycero)phosphate (BMP). Correlated confocal fluorescence - atomic force microscopy performed on endosomal membrane-mimetic supported planar lipid bilayers confirmed BMP-specific templating of the PIC J-aggregates. These data provide strong evidence for the formation of BMP-rich lipid domains during multivesicular body formation and portend the application of structured dye aggregates as markers of cellular membrane domain structure, size, and formation.
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Affiliation(s)
- Gary C H Mo
- Department of Chemical Engineering and Applied Chemistry, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College St., Toronto M5S 3E1, Canada; Department of Pharmacology, University of California San Diego, La Jolla, CA 92093, USA
| | - Christopher M Yip
- Department of Biochemistry, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College St., Toronto M5S 3E1, Canada; Department of Chemical Engineering and Applied Chemistry, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College St., Toronto M5S 3E1, Canada; Institute of Biomaterials and Biomedical Engineering, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College St., Toronto M5S 3E1, Canada.
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Sumi M, Makino A, Inaba T, Sako Y, Fujimori F, Greimel P, Kobayashi T. Photoswitchable phospholipid FRET acceptor: Detergent free intermembrane transfer assay of fluorescent lipid analogs. Sci Rep 2017; 7:2900. [PMID: 28588242 PMCID: PMC5460167 DOI: 10.1038/s41598-017-02980-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 04/20/2017] [Indexed: 12/20/2022] Open
Abstract
We have developed and characterized a novel photoswitchable phospholipid analog termed N-nitroBIPS-DPPG. The fluorescence can be switched on and off repeatedly with minimal photobleaching by UV or visible light exposure, respectively. The rather large photochromic head group is inserted deeply into the interfacial membrane region conferring a conical overall lipid shape, preference for a positive curvature and only minimal intermembrane transfer. Utilizing the switchable NBD fluorescence quenching ability of N-nitroBIPS-DPPG, a detergent free intermembrane transfer assay system for NBD modified lipids was demonstrated and validated. As NBD quenching can be turned off, total NBD associated sample fluorescence can be determined without the need of detergents. This not only reduces detergent associated systematic errors, but also simplifies assay handling and allows assay extension to detergent insoluble lipid species.
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Affiliation(s)
- Mariko Sumi
- Lipid Biology Laboratory, RIKEN, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan.,Graduate School of Humanities and Life Sciences, Tokyo Kasei University, 1-18-1, Kaga, Itabashi, Tokyo, 173-8602, Japan
| | - Asami Makino
- Lipid Biology Laboratory, RIKEN, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan.,Cellular Informatics Laboratory, RIKEN, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan
| | - Takehiko Inaba
- Lipid Biology Laboratory, RIKEN, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan.,Cellular Informatics Laboratory, RIKEN, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan
| | - Yasushi Sako
- Cellular Informatics Laboratory, RIKEN, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan
| | - Fumihiro Fujimori
- Graduate School of Humanities and Life Sciences, Tokyo Kasei University, 1-18-1, Kaga, Itabashi, Tokyo, 173-8602, Japan
| | - Peter Greimel
- Lipid Biology Laboratory, RIKEN, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan.
| | - Toshihide Kobayashi
- Lipid Biology Laboratory, RIKEN, 2-1, Hirosawa, Wako-shi, Saitama, 351-0198, Japan. .,UMR 7213 CNRS, University of Strasbourg, 67401, Illkirch, France.
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Mitchell GM, Hesketh A, Lombardi C, Ho C, Fyles TM. A membrane-spanning macrocyclic bolaamphiphile lipid mimic of archaeal lipids. CAN J CHEM 2017. [DOI: 10.1139/cjc-2016-0252] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The synthesis of a 72-membered macrocyclic tetraester bolaamphiphile is accomplished in six chemical steps from commercially available starting materials using copper-accelerated azide–alkyne coupling to close the macrocycle in high yield. Related diester amphiphiles and an acyclic tetraester bolaamphiphile were also prepared. The set of lipids bearing nitrophenyl phosphate head groups were incorporated into phospholipid vesicles but failed to undergo phosphate hydrolysis in basic conditions, undergoing efficient elimination in competition. The same lipid cores bearing phosphate-linked nitrobenzoxadiazole (NBD) head groups also incorporated into phospholipid vesicles and the NBD fluorescence was quenched with cobalt ions. The proportion of membrane-spanning bolaamphiphiles was determined from the ratio of cobalt quenching in the presence and in the absence of a detergent. The macrocyclic bolaamphiphile is incorporated into phospholipid vesicles such that 48 ± 4% of the NBD head groups are in the outer leaflet, consistent with a membrane-spanning orientation. The acyclic bolaamphiphile is incorporated with 75 ± 3% of the NBD head groups accessible to quencher in the absence of a detergent suggesting U-shaped incorporation in the outer leaflet of the bilayer membrane. In ring size and spanning ability, the macrocyclic bolaamphiphile mimics naturally occurring macrocyclic archaeal lipids.
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Affiliation(s)
- Gavin M. Mitchell
- Department of Chemistry, University of Victoria, Box 1700 STN CSC, Victoria, BC V8W 3V6, Canada
- Department of Chemistry, University of Victoria, Box 1700 STN CSC, Victoria, BC V8W 3V6, Canada
| | - Amelia Hesketh
- Department of Chemistry, University of Victoria, Box 1700 STN CSC, Victoria, BC V8W 3V6, Canada
- Department of Chemistry, University of Victoria, Box 1700 STN CSC, Victoria, BC V8W 3V6, Canada
| | - Christie Lombardi
- Department of Chemistry, University of Victoria, Box 1700 STN CSC, Victoria, BC V8W 3V6, Canada
- Department of Chemistry, University of Victoria, Box 1700 STN CSC, Victoria, BC V8W 3V6, Canada
| | - Cally Ho
- Department of Chemistry, University of Victoria, Box 1700 STN CSC, Victoria, BC V8W 3V6, Canada
- Department of Chemistry, University of Victoria, Box 1700 STN CSC, Victoria, BC V8W 3V6, Canada
| | - Thomas M. Fyles
- Department of Chemistry, University of Victoria, Box 1700 STN CSC, Victoria, BC V8W 3V6, Canada
- Department of Chemistry, University of Victoria, Box 1700 STN CSC, Victoria, BC V8W 3V6, Canada
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Pinkert T, Furkert D, Korte T, Herrmann A, Arenz C. Amplification of a FRET Probe by Lipid-Water Partition for the Detection of Acid Sphingomyelinase in Live Cells. Angew Chem Int Ed Engl 2017; 56:2790-2794. [DOI: 10.1002/anie.201611706] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Thomas Pinkert
- Institute of Chemistry; Humboldt-Universität zu Berlin; Brook-Taylor-Strasse 2 12489 Berlin Germany
| | - David Furkert
- Institute of Chemistry; Humboldt-Universität zu Berlin; Brook-Taylor-Strasse 2 12489 Berlin Germany
| | - Thomas Korte
- Institute for Biology and IRI Lifesciences; Humboldt-Universität zu Berlin; Invalidenstrasse 42 10115 Berlin Germany
| | - Andreas Herrmann
- Institute for Biology and IRI Lifesciences; Humboldt-Universität zu Berlin; Invalidenstrasse 42 10115 Berlin Germany
| | - Christoph Arenz
- Institute of Chemistry; Humboldt-Universität zu Berlin; Brook-Taylor-Strasse 2 12489 Berlin Germany
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