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Esmaelpourfarkhani M, Ramezani M, Alibolandi M, Abnous K, Taghdisi SM. Time-resolved Fluorescence DNA-based Sensors for Reducing Background Fluorescence of Environment. J Fluoresc 2023; 33:2145-2160. [PMID: 37093332 DOI: 10.1007/s10895-023-03239-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 04/04/2023] [Indexed: 04/25/2023]
Abstract
The fluorescence assay is one of the popular methods that is applied for detection of different targets. However, this method may show low sensitivity and high background in biological samples due to the natural fluorescence of different compounds in complicated samples. In addition, it inevitably affects the detection results accuracy. A fundamental solution to this problem is the use of the time-resolved fluorescence technique (TRF). The main component of this technique is the use of long fluorescence lifetime reagents. In this review, various time-resolved fluorescent reagents such as complexes of lanthanide ions, lanthanide-doped inorganic nanoparticles; Mn-doped ZnS quantum dots (QDs) and pyrene excimer are introduced. Moreover, TRF sensors, especially TRF aptasensors (DNA-based sensors) are discussed. This review will give new ideas for researchers to develop novel high-sensitive TRF sensors that can remove or decrease background fluorescence and use them for the detection of various targets in complicated samples without treatment.
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Affiliation(s)
- Masoomeh Esmaelpourfarkhani
- Targeted Drug Delivery Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
- Department of Medicinal Chemistry, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammad Ramezani
- Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mona Alibolandi
- Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Khalil Abnous
- Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Seyed Mohammad Taghdisi
- Targeted Drug Delivery Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.
- Department of Pharmaceutical Biotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
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2
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Gupta A, Chakraborty S, Ghosh D, Ramakrishnan R. Data-driven modeling of S 0 → S 1 excitation energy in the BODIPY chemical space: High-throughput computation, quantum machine learning, and inverse design. J Chem Phys 2021; 155:244102. [PMID: 34972385 DOI: 10.1063/5.0076787] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Derivatives of BODIPY are popular fluorophores due to their synthetic feasibility, structural rigidity, high quantum yield, and tunable spectroscopic properties. While the characteristic absorption maximum of BODIPY is at 2.5 eV, combinations of functional groups and substitution sites can shift the peak position by ±1 eV. Time-dependent long-range corrected hybrid density functional methods can model the lowest excitation energies offering a semi-quantitative precision of ±0.3 eV. Alas, the chemical space of BODIPYs stemming from combinatorial introduction of-even a few dozen-substituents is too large for brute-force high-throughput modeling. To navigate this vast space, we select 77 412 molecules and train a kernel-based quantum machine learning model providing <2% hold-out error. Further reuse of the results presented here to navigate the entire BODIPY universe comprising over 253 giga (253 × 109) molecules is demonstrated by inverse-designing candidates with desired target excitation energies.
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Affiliation(s)
- Amit Gupta
- Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, Hyderabad 500107, India
| | - Sabyasachi Chakraborty
- Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, Hyderabad 500107, India
| | - Debashree Ghosh
- Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Raghunathan Ramakrishnan
- Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, Hyderabad 500107, India
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3
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Podder A, Lee HJ, Kim BH. Fluorescent Nucleic Acid Systems for Biosensors. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2021. [DOI: 10.1246/bcsj.20200351] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Arup Podder
- Department of Chemistry, Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Ha Jung Lee
- Department of Chemistry, Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Byeang Hyean Kim
- Department of Chemistry, Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
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4
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Cetuk H, Maramba J, Britt M, Scott AJ, Ernst RK, Mihailescu M, Cotten ML, Sukharev S. Differential Interactions of Piscidins with Phospholipids and Lipopolysaccharides at Membrane Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:5065-5077. [PMID: 32306736 DOI: 10.1021/acs.langmuir.0c00017] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Piscidins 1 and 3 (P1 and P3) are potent antimicrobial peptides isolated from striped bass. Their mechanism of action involves formation of amphipathic α-helices on contact with phospholipids and destabilization of the microbial cytoplasmic membrane. The peptides are active against both Gram-positive and Gram-negative bacteria, suggesting easy passage across the outer membrane. Here, we performed a comparative study of these two piscidins at the air-water interface on lipopolysaccharide (LPS) monolayers modeling the outer bacterial surface of Gram-negative organisms and on phospholipid monolayers, which mimic the inner membrane. The results show that P1 and P3 are highly surface active (log KAW ∼ 6.8) and have similar affinities to phospholipid monolayers (log Klip ≈ 7.7). P1, which is more potent against Gram negatives, exhibits a much stronger partitioning into LPS monolayers (log KLPS = 8.3). Pressure-area isotherms indicate that under increasing lateral pressures, inserted P1 repartitions from phospholipid monolayers back to the subphase or to a more shallow position with in-plane areas of ∼170 Å2 per peptide, corresponding to fully folded amphipathic α-helices. In contrast, peptide expulsion from LPS occurs with areas of ∼35 Å2, suggesting that the peptides may not form the similarly oriented, rigid secondary structures when they avidly intercalate between LPS molecules. Patch-clamp experiments on Escherichia coli spheroplasts show that when P1 and P3 reach the outer surface of the bacterial cytoplasmic membrane, they produce fluctuating conductive structures at voltages above 80 mV. The data suggests that the strong activity of these piscidins against Gram-negative bacteria begins with the preferential accumulation of peptides in the outer LPS layer followed by penetration into the periplasm, where they form stable amphipathic α-helices upon contact with phospholipids and attack the energized inner membrane.
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Affiliation(s)
- Hannah Cetuk
- Biology Department, University of Maryland-College Park, 4094 Campus Drive, College Park, Maryland 20742, United States
| | - Joseph Maramba
- Biology Department, University of Maryland-College Park, 4094 Campus Drive, College Park, Maryland 20742, United States
| | - Madolyn Britt
- Biology Department, University of Maryland-College Park, 4094 Campus Drive, College Park, Maryland 20742, United States
| | - Alison J Scott
- Department of Microbial Pathogenesis, University of Maryland-Baltimore, Baltimore, Maryland 21201, United States
| | - Robert K Ernst
- Department of Microbial Pathogenesis, University of Maryland-Baltimore, Baltimore, Maryland 21201, United States
| | - Mihaela Mihailescu
- Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850, United States
| | - Myriam L Cotten
- Department of Applied Science, College of William and Mary, Williamsburg, Virginia 23185, United States
| | - Sergei Sukharev
- Biology Department, University of Maryland-College Park, 4094 Campus Drive, College Park, Maryland 20742, United States
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5
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Varandas PAMM, Cobb AJA, Segundo MA, Silva EMP. Emergent Glycerophospholipid Fluorescent Probes: Synthesis and Applications. Bioconjug Chem 2019; 31:417-435. [DOI: 10.1021/acs.bioconjchem.9b00660] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Pedro A. M. M. Varandas
- LAQV, REQUIMTE, Department of Chemistry Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Alexander J. A. Cobb
- Department of Chemistry, King’s College London, 7 Trinity Street, London SE1 1DB, United Kingdom
| | - Marcela A. Segundo
- LAQV, REQUIMTE, Department of Chemistry Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Eduarda M. P. Silva
- LAQV, REQUIMTE, Department of Chemistry Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
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6
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Hu SK, Lo FY, Hsieh CC, Chao L. Sensing Ability and Formation Criterion of Fluid Supported Lipid Bilayer Coated Graphene Field-Effect Transistors. ACS Sens 2019; 4:892-899. [PMID: 30817891 DOI: 10.1021/acssensors.8b01623] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Supported lipid bilayers (SLBs) have been widely used to provide native environments for membrane protein studies. In this study, we utilized graphene field-effect transistors (GFETs) coated with a fluid SLB to perform label-free detection of membrane-associated ligand-receptor interactions in their native lipid bilayer environment. It is known that the analyte-binding event needs to occur within the Debye length for it to be significantly sensed by an FET sensor. However, the thickness of a lipid bilayer is around 4-5-nm-thick, which is larger than the Debye length of a solution with physiologically relevant ionic strength. There is thus a question of whether an FET sensor can detect the binding event above the bilayer. In this study, we show how the existence of an SLB can influence the effective detection distance and the formation criterion of a fluid and continuous SLB on a graphene surface. We discovered that the water intercalation between the graphene and the underlying silica substrate hinders the SLB formation but is required for the stable electrical recording by a GFET. To verify the existence of a fluid SLB on graphene, which was previously complicated by the graphene fluorescence quenching effect, we developed a modified fluorescence recovery after photobleaching method. In addition, our results showed that SLB coated GFETs can quantitatively detect ligand binding onto the receptors embedded in the SLBs. The comparison of our experimental data with a theoretical model shows that the contribution of the SLB acyl chain hydrophobic region to the screening effect can be negligible and, therefore, that the effective detection region can extend beyond the SLB.
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Affiliation(s)
- Shu-Kai Hu
- Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan
| | - Fang-Yen Lo
- Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan
| | - Chih-Chen Hsieh
- Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan
| | - Ling Chao
- Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan
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7
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Tretiakova D, Alekseeva A, Galimzyanov T, Boldyrev A, Chernyadyev A, Ermakov Y, Batishchev O, Vodovozova E, Boldyrev I. Lateral stress profile and fluorescent lipid probes. FRET pair of probes that introduces minimal distortions into lipid packing. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2337-2347. [DOI: 10.1016/j.bbamem.2018.05.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 05/17/2018] [Accepted: 05/30/2018] [Indexed: 12/31/2022]
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8
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Bardon K, Selfridge S, Adams DS, Minns RA, Pawle R, Adams TC, Takiff L. Synthesis of Water-Soluble Far-Red-Emitting Amphiphilic BODIPY Dyes. ACS OMEGA 2018; 3:13195-13199. [PMID: 30411029 PMCID: PMC6217593 DOI: 10.1021/acsomega.8b01487] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 10/01/2018] [Indexed: 05/26/2023]
Abstract
We report the synthesis of two water-soluble BODIPY dyes with far-red absorption and near-infrared fluorescence following cell membrane insertion. Introduction of dicationic or dianionic groups imparts water solubility and prevents translocation of the dye through the plasma membrane for highly effective labeling. The dicationic form is particularly well localized to the plasma membrane and resists quenching even after >8 min of continuous light exposure. The dyes are almost completely nonemissive in water and other highly polar solvents, but display high-fluorescence yields in chloroform and upon insertion into the extracellular leaflet.
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Affiliation(s)
- Kevin
M. Bardon
- Akita
Innovations LLC, 267
Boston Road, Suite 11, North Billerica, Massachusetts 01862, United States
| | - Scott Selfridge
- Akita
Innovations LLC, 267
Boston Road, Suite 11, North Billerica, Massachusetts 01862, United States
| | - Dany S. Adams
- Tufts
University, Tufts Center for
Regenerative & Developmental Biology, 200 Boston Avenue, Medford, Massachusetts 02155, United States
| | - Richard A. Minns
- Akita
Innovations LLC, 267
Boston Road, Suite 11, North Billerica, Massachusetts 01862, United States
| | - Robert Pawle
- Akita
Innovations LLC, 267
Boston Road, Suite 11, North Billerica, Massachusetts 01862, United States
| | - Timothy C. Adams
- Akita
Innovations LLC, 267
Boston Road, Suite 11, North Billerica, Massachusetts 01862, United States
| | - Larry Takiff
- Akita
Innovations LLC, 267
Boston Road, Suite 11, North Billerica, Massachusetts 01862, United States
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9
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Sæle Ø, Rød KEL, Quinlivan VH, Li S, Farber SA. A novel system to quantify intestinal lipid digestion and transport. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:948-957. [PMID: 29778665 PMCID: PMC6054555 DOI: 10.1016/j.bbalip.2018.05.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 05/04/2018] [Accepted: 05/16/2018] [Indexed: 02/05/2023]
Abstract
The zebrafish larva is a powerful tool for the study of dietary triglyceride (TG) digestion and how fatty acids (FA) derived from dietary lipids are absorbed, metabolized and distributed to the body. While fluorescent FA analogues have enabled visualization of FA metabolism, methods for specifically assaying TG digestion are badly needed. Here we present a novel High Performance Liquid Chromatography (HPLC) method that quantitatively differentiates TG and phospholipid (PL) molecules with one or two fluorescent FA analogues. We show how this tool may be used to discriminate between undigested and digested TG or phosphatidylcholine (PC), and also the products of TG or PC that have been digested, absorbed and re-synthesized into new lipid molecules. Using this approach, we explored the dietary requirement of zebrafish larvae for phospholipids. Here we demonstrate that dietary TG is digested and absorbed in the intestinal epithelium, but without dietary PC, TG accumulates and is not transported out of the enterocytes. Consequently, intestinal ER stress increases and the ingested lipid is not available support the energy and metabolic needs of other tissues. In TG diets with PC, TG is readily transported from the intestine and subsequently metabolized.
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Affiliation(s)
- Øystein Sæle
- Institute of Marine Research, Strandgaten 229, 5004 Bergen, Norway.
| | - Kari Elin L Rød
- Institute of Marine Research, Strandgaten 229, 5004 Bergen, Norway
| | - Vanessa H Quinlivan
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA; The Johns Hopkins University, Department of Biology, Baltimore, MD 21218, USA
| | - Shengrong Li
- Avanti Polar Lipids, Inc., 700 Industrial Park Drive, Alabaster, AL 35007-9105, USA
| | - Steven A Farber
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA; The Johns Hopkins University, Department of Biology, Baltimore, MD 21218, USA.
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10
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Rogacki MK, Golfetto O, Tobin SJ, Li T, Biswas S, Jorand R, Zhang H, Radoi V, Ming Y, Svenningsson P, Ganjali D, Wakefield DL, Sideris A, Small AR, Terenius L, Jovanović‐Talisman T, Vukojević V. Dynamic lateral organization of opioid receptors (kappa, mu wt and mu N40D ) in the plasma membrane at the nanoscale level. Traffic 2018; 19:690-709. [PMID: 29808515 PMCID: PMC6120469 DOI: 10.1111/tra.12582] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 05/06/2018] [Accepted: 05/18/2018] [Indexed: 02/06/2023]
Abstract
Opioid receptors are important pharmacological targets for the management of numerous medical conditions (eg, severe pain), but they are also the gateway to the development of deleterious side effects (eg, opiate addiction). Opioid receptor signaling cascades are well characterized. However, quantitative information regarding their lateral dynamics and nanoscale organization in the plasma membrane remains limited. Since these dynamic properties are important determinants of receptor function, it is crucial to define them. Herein, the nanoscale lateral dynamics and spatial organization of kappa opioid receptor (KOP), wild type mu opioid receptor (MOPwt ), and its naturally occurring isoform (MOPN40D ) were quantitatively characterized using fluorescence correlation spectroscopy and photoactivated localization microscopy. Obtained results, supported by ensemble-averaged Monte Carlo simulations, indicate that these opioid receptors dynamically partition into different domains. In particular, significant exclusion from GM1 ganglioside-enriched domains and partial association with cholesterol-enriched domains was observed. Nanodomain size, receptor population density and the fraction of receptors residing outside of nanodomains were receptor-specific. KOP-containing domains were the largest and most densely populated, with the smallest fraction of molecules residing outside of nanodomains. The opposite was true for MOPN40D . Moreover, cholesterol depletion dynamically regulated the partitioning of KOP and MOPwt , whereas this effect was not observed for MOPN40D .
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Affiliation(s)
- Maciej K. Rogacki
- Department of Clinical NeuroscienceCenter for Molecular Medicine, Karolinska InstituteStockholmSweden
| | - Ottavia Golfetto
- Department of Molecular Medicine, Beckman Research Institute, City of HopeDuarteCalifornia
| | - Steven J. Tobin
- Department of Molecular Medicine, Beckman Research Institute, City of HopeDuarteCalifornia
| | - Tianyi Li
- Department of Clinical NeuroscienceCenter for Molecular Medicine, Karolinska InstituteStockholmSweden
| | - Sunetra Biswas
- Department of Molecular Medicine, Beckman Research Institute, City of HopeDuarteCalifornia
| | - Raphael Jorand
- Department of Molecular Medicine, Beckman Research Institute, City of HopeDuarteCalifornia
| | - Huiying Zhang
- Department of Molecular Medicine, Beckman Research Institute, City of HopeDuarteCalifornia
| | - Vlad Radoi
- Department of Clinical NeuroscienceCenter for Molecular Medicine, Karolinska InstituteStockholmSweden
| | - Yu Ming
- Department of Clinical NeuroscienceCenter for Molecular Medicine, Karolinska InstituteStockholmSweden
| | - Per Svenningsson
- Department of Clinical NeuroscienceCenter for Molecular Medicine, Karolinska InstituteStockholmSweden
| | - Daniel Ganjali
- Department of Mechanical and Aerospace EngineeringThe Henry Samueli School of Engineering, University of CaliforniaIrvineCalifornia
| | - Devin L. Wakefield
- Department of Molecular Medicine, Beckman Research Institute, City of HopeDuarteCalifornia
| | - Athanasios Sideris
- Department of Mechanical and Aerospace EngineeringThe Henry Samueli School of Engineering, University of CaliforniaIrvineCalifornia
| | - Alexander R. Small
- Department of Physics and AstronomyCalifornia State Polytechnic UniversityPomonaCalifornia
| | - Lars Terenius
- Department of Clinical NeuroscienceCenter for Molecular Medicine, Karolinska InstituteStockholmSweden
- Department of Molecular and Cellular NeurosciencesThe Scripps Research InstituteLa JollaCalifornia
| | | | - Vladana Vukojević
- Department of Clinical NeuroscienceCenter for Molecular Medicine, Karolinska InstituteStockholmSweden
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11
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Sarmento MJ, Coutinho A, Fedorov A, Prieto M, Fernandes F. Membrane Order Is a Key Regulator of Divalent Cation-Induced Clustering of PI(3,5)P 2 and PI(4,5)P 2. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:12463-12477. [PMID: 28961003 DOI: 10.1021/acs.langmuir.7b00666] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Although the evidence for the presence of functionally important nanosized phosphorylated phosphoinositide (PIP)-rich domains within cellular membranes has accumulated, very limited information is available regarding the structural determinants for compartmentalization of these phospholipids. Here, we used a combination of fluorescence spectroscopy and microscopy techniques to characterize differences in divalent cation-induced clustering of PI(4,5)P2 and PI(3,5)P2. Through these methodologies we were able to detect differences in divalent cation-induced clustering efficiency and cluster size. Ca2+-induced PI(4,5)P2 clusters are shown to be significantly larger than the ones observed for PI(3,5)P2. Clustering of PI(4,5)P2 is also detected at physiological concentrations of Mg2+, suggesting that in cellular membranes, these molecules are constitutively driven to clustering by the high intracellular concentration of divalent cations. Importantly, it is shown that lipid membrane order is a key factor in the regulation of clustering for both PIP isoforms, with a major impact on cluster sizes. Clustered PI(4,5)P2 and PI(3,5)P2 are observed to present considerably higher affinity for more ordered lipid phases than the monomeric species or than PI(4)P, possibly reflecting a more general tendency of clustered lipids for insertion into ordered domains. These results support a model for the description of the lateral organization of PIPs in cellular membranes, where both divalent cation interaction and membrane order are key modulators defining the lateral organization of these lipids.
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Affiliation(s)
- Maria J Sarmento
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon , 1649-004 Lisbon, Portugal
- J. Heyrovský Inst. Physical Chemistry of the A.S.C.R. v.v.i. , 182 23 Prague, Czech Republic
| | - Ana Coutinho
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon , 1649-004 Lisbon, Portugal
- Departamento de Química e Bioquímica, FCUL, University of Lisbon , 1649-004 Lisbon, Portugal
| | - Aleksander Fedorov
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon , 1649-004 Lisbon, Portugal
| | - Manuel Prieto
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon , 1649-004 Lisbon, Portugal
| | - Fábio Fernandes
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon , 1649-004 Lisbon, Portugal
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa , Campus da Caparica, 2829-516 Caparica, Portugal
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12
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Mazinani SA, Moradi F, Stuart JA, Yan H. Microwave Irradiation of PC3 Cells at Constant Culture Temperature Alters the Incorporation of BODIPY into Cells and Reduction of MTT. ChemistrySelect 2017. [DOI: 10.1002/slct.201701445] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Sina Atrin Mazinani
- Department of Chemistry and Centre for Biotechnology; Brock University; 1812 Sir Isaac Brock Way St. Catharines, Ontario L2S 3 A1 Canada
| | - Fereshteh Moradi
- Department of Biological Sciences and Centre for Biotechnology; Brock University; 1812 Sir Isaac Brock Way St. Catharines, Ontario L2S 3 A1 Canada
| | - Jeffrey A. Stuart
- Department of Biological Sciences and Centre for Biotechnology; Brock University; 1812 Sir Isaac Brock Way St. Catharines, Ontario L2S 3 A1 Canada
| | - Hongbin Yan
- Department of Chemistry and Centre for Biotechnology; Brock University; 1812 Sir Isaac Brock Way St. Catharines, Ontario L2S 3 A1 Canada
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13
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Gnanasambandam R, Ghatak C, Yasmann A, Nishizawa K, Sachs F, Ladokhin AS, Sukharev SI, Suchyna TM. GsMTx4: Mechanism of Inhibiting Mechanosensitive Ion Channels. Biophys J 2017; 112:31-45. [PMID: 28076814 PMCID: PMC5231890 DOI: 10.1016/j.bpj.2016.11.013] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 10/12/2016] [Accepted: 11/03/2016] [Indexed: 12/21/2022] Open
Abstract
GsMTx4 is a spider venom peptide that inhibits cationic mechanosensitive channels (MSCs). It has six lysine residues that have been proposed to affect membrane binding. We synthesized six analogs with single lysine-to-glutamate substitutions and tested them against Piezo1 channels in outside-out patches and independently measured lipid binding. Four analogs had ∼20% lower efficacy than the wild-type (WT) peptide. The equilibrium constants calculated from the rates of inhibition and washout did not correlate with the changes in inhibition. The lipid association strength of the WT GsMTx4 and the analogs was determined by tryptophan autofluorescence quenching and isothermal calorimetry with membrane vesicles and showed no significant differences in binding energy. Tryptophan fluorescence-quenching assays showed that both WT and analog peptides bound superficially near the lipid-water interface, although analogs penetrated deeper. Peptide-lipid association, as a function of lipid surface pressure, was investigated in Langmuir monolayers. The peptides occupied a large fraction of the expanded monolayer area, but that fraction was reduced by peptide expulsion as the pressure approached the monolayer-bilayer equivalence pressure. Analogs with compromised efficacy had pressure-area isotherms with steeper slopes in this region, suggesting tighter peptide association. The pressure-dependent redistribution of peptide between "deep" and "shallow" binding modes was supported by molecular dynamics (MD) simulations of the peptide-monolayer system under different area constraints. These data suggest a model placing GsMTx4 at the membrane surface, where it is stabilized by the lysines, and occupying a small fraction of the surface area in unstressed membranes. When applied tension reduces lateral pressure in the lipids, the peptides penetrate deeper acting as "area reservoirs" leading to partial relaxation of the outer monolayer, thereby reducing the effective magnitude of stimulus acting on the MSC gate.
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Affiliation(s)
| | - Chiranjib Ghatak
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas
| | - Anthony Yasmann
- Department of Biology, University of Maryland, College Park, Maryland
| | - Kazuhisa Nishizawa
- Clinical Laboratory Science, Teikyo University School of Medical Technology, Tokyo, Japan
| | - Frederick Sachs
- Department of Physiology and Biophysics, State University of New York, Buffalo, New York
| | - Alexey S Ladokhin
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas
| | - Sergei I Sukharev
- Department of Biology, University of Maryland, College Park, Maryland
| | - Thomas M Suchyna
- Department of Physiology and Biophysics, State University of New York, Buffalo, New York.
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14
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Bacalum M, Wang L, Boodts S, Yuan P, Leen V, Smisdom N, Fron E, Knippenberg S, Fabre G, Trouillas P, Beljonne D, Dehaen W, Boens N, Ameloot M. A Blue-Light-Emitting BODIPY Probe for Lipid Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:3495-3505. [PMID: 27003513 DOI: 10.1021/acs.langmuir.6b00478] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Here we describe a new BODIPY-based membrane probe (1) that provides an alternative to dialkylcarbocyanine dyes, such as DiI-C18, that can be excited in the blue spectral region. Compound 1 has unbranched octadecyl chains at the 3,5-positions and a meso-amino function. In organic solvents, the absorption and emission maxima of 1 are determined mainly by solvent acidity and dipolarity. The fluorescence quantum yield is high and reaches 0.93 in 2-propanol. The fluorescence decays are well fitted with a single-exponential in pure solvents and in small and giant unilamellar vesicles (GUV) with a lifetime of ca. 4 ns. Probe 1 partitions in the same lipid phase as DiI-C18(5) for lipid mixtures containing sphingomyelin and for binary mixtures of dipalmitoylphosphatidylcholine (DPPC) and dioleoylphosphatidylcholine (DOPC). The lipid phase has no effect on the fluorescence lifetime but influences the fluorescence anisotropy. The translational diffusion coefficients of 1 in GUVs and OLN-93 cells are of the same order as those reported for DiI-C18. The directions of the absorption and emission transition dipole moments of 1 are calculated to be parallel. This is reflected in the high steady-state fluorescence anisotropy of 1 in high ordered lipid phases. Molecular dynamic simulations of 1 in a model of the DOPC bilayer indicate that the average angle of the transition moments with respect to membrane normal is ca. 70°, which is comparable with the value reported for DiI-C18.
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Affiliation(s)
- Mihaela Bacalum
- Biomedical Research Institute, Hasselt University , Agoralaan Building C, 3590, Diepenbeek, Belgium
- Department of Life and Environmental Physics, Horia Hulubei National Institute for Physics and Nuclear Engineering , Reactorului 30, Măgurele, 077125, Romania
| | - Lina Wang
- Department of Chemistry, Katholieke Universiteit Leuven (KU Leuven) , Celestijnenlaan 200f - bus 02404, 3001 Leuven, Belgium
| | - Stijn Boodts
- Department of Chemistry, Katholieke Universiteit Leuven (KU Leuven) , Celestijnenlaan 200f - bus 02404, 3001 Leuven, Belgium
| | - Peijia Yuan
- Department of Chemistry, Katholieke Universiteit Leuven (KU Leuven) , Celestijnenlaan 200f - bus 02404, 3001 Leuven, Belgium
| | - Volker Leen
- Department of Chemistry, Katholieke Universiteit Leuven (KU Leuven) , Celestijnenlaan 200f - bus 02404, 3001 Leuven, Belgium
| | - Nick Smisdom
- Biomedical Research Institute, Hasselt University , Agoralaan Building C, 3590, Diepenbeek, Belgium
| | - Eduard Fron
- Department of Chemistry, Katholieke Universiteit Leuven (KU Leuven) , Celestijnenlaan 200f - bus 02404, 3001 Leuven, Belgium
| | - Stefan Knippenberg
- Biomedical Research Institute, Hasselt University , Agoralaan Building C, 3590, Diepenbeek, Belgium
- Division of Theoretical Chemistry and Biology, KTH Royal Institute of Technology, School of Biotechnology , Roslagstullsbacken 15, S-106 91 Stockholm, Sweden
| | - Gabin Fabre
- LCSN-EA1069, Faculté de Pharmacie, Université de Limoges , 2, rue du Dr. Marcland, 87025 Limoges Cedex, France
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University , tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Patrick Trouillas
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University , tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic
- INSERM UMR-S850, Faculté de Pharmacie, Université de Limoges , 2 rue du Docteur Marcland, 87025 Limoges Cedex, France
- Service de Chimie des Matériaux Nouveaux, Université de Mons , Place du Parc 20, B-7000 Mons, Belgium
| | - David Beljonne
- Service de Chimie des Matériaux Nouveaux, Université de Mons , Place du Parc 20, B-7000 Mons, Belgium
| | - Wim Dehaen
- Department of Chemistry, Katholieke Universiteit Leuven (KU Leuven) , Celestijnenlaan 200f - bus 02404, 3001 Leuven, Belgium
| | - Noël Boens
- Department of Chemistry, Katholieke Universiteit Leuven (KU Leuven) , Celestijnenlaan 200f - bus 02404, 3001 Leuven, Belgium
| | - Marcel Ameloot
- Biomedical Research Institute, Hasselt University , Agoralaan Building C, 3590, Diepenbeek, Belgium
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15
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Yalagala RS, Mazinani SA, Maddalena LA, Stuart JA, Yan F, Yan H. Microwave-assisted syntheses of BODIPY–sugar conjugates through click chemistry and conjugate assembly into liposomes. Carbohydr Res 2016; 424:15-20. [DOI: 10.1016/j.carres.2016.02.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 01/25/2016] [Accepted: 02/01/2016] [Indexed: 11/28/2022]
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16
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Pakhomov AA, Kononevich YN, Stukalova MV, Svidchenko EA, Surin NM, Cherkaev GV, Shchegolikhina OI, Martynov VI, Muzafarov AM. Synthesis and photophysical properties of a new BODIPY-based siloxane dye. Tetrahedron Lett 2016. [DOI: 10.1016/j.tetlet.2016.01.059] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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17
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Yasmann A, Sukharev S. Properties of diphytanoyl phospholipids at the air-water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 31:350-357. [PMID: 25474305 DOI: 10.1021/la503800g] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Diphytanoylphosphatidyl choline (DPhPC) is a synthetic ester lipid with methylated tails found in archaeal ether lipids. Because of the stability of DPhPC bilayers and the absence of phase transitions over a broad range of temperatures, the lipid is used as an artificial membrane matrix for the reconstitution of channels, pumps, and membrane-active peptides. We characterized monomolecular films made of DPhPC and its natural ether analog DOPhPC at the air-water interface. We measured compression isotherms and dipole potentials of films made of DPhPC, DPhPE, and DOPhPC. We determined that at 40 mN/m the molecular area of DPhPC is 81.2 Å(2), consistent with X-ray and neutron scattering data obtained in liposomes. This indicates that 40 mN/m is the monolayer-bilayer equivalence pressure for this lipid. At this packing density, the compressibility modulus (Cs(-1 )= 122 ± 7 mN/m) and interfacial dipole potential (V = 355 ± 16 mV) were near their maximums. The molecular dipole moment was estimated to be 0.64 ± 0.02 D. The ether DOPhPC compacted to 70.4 Å(2)/lipid at 40 mN/m displaying a peak compressibility similar to that of DPhPC. The maximal dipole potential of the ether lipid was about half of that for DPhPC at this density, and the elemental dipole moment was about a quarter. The spreading of DPhPC and DOPhPC liposomes reduced the surface tension of the aqueous phase by 46 and 49 mN/m, respectively. This corresponds well to the monolayer collapse pressure. The equilibration time shortened as the temperature increased from 20 to 60 °C, but the surface pressure at equilibrium did not change. The data illustrates the properties of branched chains and the contributions of ester bonds in setting the mechanical and electrostatic parameters of diphytanoyl lipids. These properties determine an environment in which reconstituted voltage- or mechano-activated proteins may function. Electrostatic properties are important in the preparation of asymmetric folded bilayers, whereas lateral compressibility defines the tension in mechanically stimulated droplet interface bilayers.
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Affiliation(s)
- Anthony Yasmann
- Department of Biology, University of Maryland , College Park, Maryland 20742, United States
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18
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Miyares RL, de Rezende VB, Farber SA. Zebrafish yolk lipid processing: a tractable tool for the study of vertebrate lipid transport and metabolism. Dis Model Mech 2014; 7:915-27. [PMID: 24812437 PMCID: PMC4073280 DOI: 10.1242/dmm.015800] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Dyslipidemias are a major cause of morbidity and mortality in the world, particularly in developed nations. Investigating lipid and lipoprotein metabolism in experimentally tractable animal models is a crucial step towards understanding and treating human dyslipidemias. The zebrafish, a well-established embryological model, is emerging as a notable system for studies of lipid metabolism. Here, we describe the value of the lecithotrophic, or yolk-metabolizing, stages of the zebrafish as a model for studying lipid metabolism and lipoprotein transport. We demonstrate methods to assay yolk lipid metabolism in embryonic and larval zebrafish. Injection of labeled fatty acids into the zebrafish yolk promotes efficient uptake into the circulation and rapid metabolism. Using a genetic model for abetalipoproteinemia, we show that the uptake of labeled fatty acids into the circulation is dependent on lipoprotein production. Furthermore, we examine the metabolic fate of exogenously delivered fatty acids by assaying their incorporation into complex lipids. Moreover, we demonstrate that this technique is amenable to genetic and pharmacologic studies.
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Affiliation(s)
- Rosa L Miyares
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA. Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Vitor B de Rezende
- Department of Mental Health, School of Medicine of Federal University of Minas Gerais, 30130-100 Belo Horizonte, Brazil
| | - Steven A Farber
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA.
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19
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Zhai X, Boldyrev IA, Mizuno N, Momsen MM, Molotkovsky JG, Brockman H, Brown RE. Nanoscale packing differences in sphingomyelin and phosphatidylcholine revealed by BODIPY fluorescence in monolayers: physiological implications. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:3154-3164. [PMID: 24564829 PMCID: PMC3983355 DOI: 10.1021/la4047098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 01/24/2014] [Indexed: 06/03/2023]
Abstract
Phosphatidycholines (PC) with two saturated acyl chains (e.g., dipalmitoyl) mimic natural sphingomyelin (SM) by promoting raft formation in model membranes. However, sphingoid-based lipids, such as SM, rather than saturated-chain PCs have been implicated as key components of lipid rafts in biomembranes. These observations raise questions about the physical packing properties of the phase states that can be formed by these two major plasma membrane lipids with identical phosphocholine headgroups. To investigate, we developed a monolayer platform capable of monitoring changes in surface fluorescence by acquiring multiple spectra during measurement of a lipid force-area isotherm. We relied on the concentration-dependent emission changes of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)-labeled PC to detect nanoscale alterations in lipid packing and phase state induced by monolayer lateral compression. The BODIPY-PC probe contained an indacene ring with four symmetrically located methyl (Me) substituents to enhance localization to the lipid hydrocarbon region. Surface fluorescence spectra indicated changes in miscibility even when force-area isotherms showed no deviation from ideal mixing behavior in the surface pressure versus cross-sectional molecular area response. We detected slightly better mixing of Me4-BODIPY-8-PC with the fluid-like, liquid expanded phase of 1-palmitoyl-2-oleoyl-PC compared to N-oleoyl-SM. Remarkably, in the gel-like, liquid condensed phase, Me4-BODIPY-8-PC mixed better with N-palmitoyl-SM than dipalmitoyl-PC, suggesting naturally abundant SMs with saturated acyl chains form gel-like lipid phase(s) with enhanced ability to accommodate deeply embedded components compared to dipalmitoyl-PC gel phase. The findings reveal a fundamental difference in the lateral packing properties of SM and PC that occurs even when their acyl chains match.
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Affiliation(s)
- Xiuhong Zhai
- Hormel
Institute, University of Minnesota, 801 16th Ave NE, Austin, Minnesota 55912, United States
| | - Ivan A. Boldyrev
- Shemyakin-Ovichinnikov
Institute of Bioorganic Chemistry, Russian
Academy of Sciences, Moscow, Russian Federation
| | - Nancy
K. Mizuno
- Hormel
Institute, University of Minnesota, 801 16th Ave NE, Austin, Minnesota 55912, United States
| | - Maureen M. Momsen
- Hormel
Institute, University of Minnesota, 801 16th Ave NE, Austin, Minnesota 55912, United States
| | - Julian G. Molotkovsky
- Shemyakin-Ovichinnikov
Institute of Bioorganic Chemistry, Russian
Academy of Sciences, Moscow, Russian Federation
| | - Howard
L. Brockman
- Hormel
Institute, University of Minnesota, 801 16th Ave NE, Austin, Minnesota 55912, United States
| | - Rhoderick E. Brown
- Hormel
Institute, University of Minnesota, 801 16th Ave NE, Austin, Minnesota 55912, United States
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20
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Senning EN, Collins MD, Stratiievska A, Ufret-Vincenty CA, Gordon SE. Regulation of TRPV1 ion channel by phosphoinositide (4,5)-bisphosphate: the role of membrane asymmetry. J Biol Chem 2014; 289:10999-11006. [PMID: 24599956 DOI: 10.1074/jbc.m114.553180] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Membrane asymmetry is essential for generating second messengers that act in the cytosol and for trafficking of membrane proteins and membrane lipids, but the role of asymmetry in regulating membrane protein function remains unclear. Here we show that the signaling lipid phosphoinositide 4,5-bisphosphate (PI(4,5)P2) has opposite effects on the function of TRPV1 ion channels depending on which leaflet of the cell membrane it resides in. We observed potentiation of capsaicin-activated TRPV1 currents by PI(4,5)P2 in the intracellular leaflet of the plasma membrane but inhibition of capsaicin-activated currents when PI(4,5)P2 was in both leaflets of the membrane, although much higher concentrations of PI(4,5)P2 in the extracellular leaflet were required for inhibition compared with the concentrations of PI(4,5)P2 in the intracellular leaflet that produced activation. Patch clamp fluorometry using a synthetic PI(4,5)P2 whose fluorescence reports its concentration in the membrane indicates that PI(4,5)P2 must incorporate into the extracellular leaflet for its inhibitory effects to be observed. The asymmetry-dependent effect of PI(4,5)P2 may resolve the long standing controversy about whether PI(4,5)P2 is an activator or inhibitor of TRPV1. Our results also underscore the importance of membrane asymmetry and the need to consider its influence when studying membrane proteins reconstituted into synthetic bilayers.
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Affiliation(s)
- Eric N Senning
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington 98195-7290 and
| | - Marcus D Collins
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington 98195-7290 and
| | - Anastasiia Stratiievska
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington 98195-7290 and; Laboratory of Biophysics of Ion Channels, Department of General Physiology of the Nervous System, Bogomoletz Institute of Physiology, International Center for Molecular Physiology, 01024 Kyiv, Ukraine
| | - Carmen A Ufret-Vincenty
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington 98195-7290 and
| | - Sharona E Gordon
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington 98195-7290 and.
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21
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Salvemini IL, Gau D, Reid J, Bagatolli L, Macmillan A, Moens P. Low PIP2 molar fractions induce nanometer size clustering in giant unilamellar vesicles. Chem Phys Lipids 2014; 177:51-63. [DOI: 10.1016/j.chemphyslip.2013.11.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 09/29/2013] [Accepted: 11/11/2013] [Indexed: 01/08/2023]
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22
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Gayathri T, Barui AK, Prashanthi S, Patra CR, Singh SP. meso-Substituted BODIPY fluorescent probes for cellular bio-imaging and anticancer activity. RSC Adv 2014. [DOI: 10.1039/c4ra07424f] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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23
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Sarmento MJ, Coutinho A, Fedorov A, Prieto M, Fernandes F. Ca(2+) induces PI(4,5)P2 clusters on lipid bilayers at physiological PI(4,5)P2 and Ca(2+) concentrations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:822-30. [PMID: 24316170 DOI: 10.1016/j.bbamem.2013.11.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 11/22/2013] [Accepted: 11/26/2013] [Indexed: 01/22/2023]
Abstract
Calcium has been shown to induce clustering of PI(4,5)P2 at high and non-physiological concentrations of both the divalent ion and the phosphatidylinositol, or on supported lipid monolayers. In lipid bilayers at physiological conditions, clusters are not detected through microscopic techniques. Here, we aimed to determine through spectroscopic methodologies if calcium plays a role in PI(4,5)P2 lateral distribution on lipid bilayers under physiological conditions. Using several different approaches which included information on fluorescence quantum yield, polarization, spectra and diffusion properties of a fluorescent derivative of PI(4,5)P2 (TopFluor(TF)-PI(4,5)P2), we show that Ca(2+) promotes PI(4,5)P2 clustering in lipid bilayers at physiological concentrations of both Ca(2+) and PI(4,5)P2. Fluorescence depolarization data of TF-PI(4,5)P2 in the presence of calcium suggests that under physiological concentrations of PI(4,5)P2 and calcium, the average cluster size comprises ~15 PI(4,5)P2 molecules. The presence of Ca(2+)-induced PI(4,5)P2 clusters is supported by FCS data. Additionally, calcium mediated PI(4,5)P2 clustering was more pronounced in liquid ordered (lo) membranes, and the PI(4,5)P2-Ca(2+) clusters presented an increased affinity for lo domains. In this way, PI(4,5)P2 could function as a lipid calcium sensor and the increased efficiency of calcium-mediated PI(4,5)P2 clustering on lo domains might provide targeted nucleation sites for PI(4,5)P2 clusters upon calcium stimulus.
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Affiliation(s)
- Maria J Sarmento
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal
| | - Ana Coutinho
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal; Departamento de Química e Bioquímica, FCUL, University of Lisbon, Lisbon, Portugal
| | - Aleksander Fedorov
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal
| | - Manuel Prieto
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal
| | - Fabio Fernandes
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal.
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24
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Kim KT, Kim BH. A fluorescent probe for the 3'-overhang of telomeric DNA based on competition between two interstrand G-quadruplexes. Chem Commun (Camb) 2013; 49:1717-9. [PMID: 23344213 DOI: 10.1039/c3cc37504h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A 6-mer oligonucleotide containing a fluorescent (Bod)U moiety has been used as a novel fluorescent probe for the 3'-overhang of telomeric DNA based on competition between non-fluorescent tetramolecular and fluorescent (3+1) intermolecular G-quadruplexes.
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Affiliation(s)
- Ki Tae Kim
- Department of Chemistry, BK School of Molecular Science, Pohang University of Science and Technology, Pohang 790-784, South Korea
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25
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Rodríguez HB, San Román E. Effect of Concentration on the Photophysics of Dyes in Light-Scattering Materials. Photochem Photobiol 2013; 89:1273-82. [DOI: 10.1111/php.12107] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 05/22/2013] [Indexed: 01/30/2023]
Affiliation(s)
- Hernán B. Rodríguez
- INIFTA, Facultad de Ciencias Exactas; Universidad Nacional; La Plata Argentina
| | - Enrique San Román
- INQUIMAE / DQIAyQF, Facultad de Ciencias Exactas y Naturales; Universidad de Buenos Aires; Argentina
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26
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Flores-Rizo JO, Esnal I, Osorio-Martínez CA, Gómez-Durán CFA, Bañuelos J, López Arbeloa I, Pannell KH, Metta-Magaña AJ, Peña-Cabrera E. 8-Alkoxy- and 8-aryloxy-BODIPYs: straightforward fluorescent tagging of alcohols and phenols. J Org Chem 2013; 78:5867-77. [PMID: 23721096 DOI: 10.1021/jo400417h] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
We demonstrate herein that both alcohols and phenols can be tagged with a BODIPY (borondipyrromethene) moiety to yield highly fluorescent products. Thus, 8-(methylthio)-BODIPY (1) undergoes an S(N)Ar-type reaction with a host of alcohols and phenols in the presence of a base and a Cu(I) additive. The BODIPY dyes bearing alkoxy or nonfunctionalized phenoxy moieties are characterized by a highly efficient fluorescence emission, regardless of the media, in the blue-green part of the visible region. Complementary to this, the presence of electron-donor groups at the aryl ring leads to an intramolecular charge-transfer process, which quenches the fluorescence mainly in polar media. In addition to simple alcohols and phenols, four natural products (eugenol, menthol, cholesterol, and estrone) were labeled in a simple fashion. X-ray structures of the cholesterol and estrone derivatives are discussed. In fact, the BODIPY bearing cholesterol stands out as a bright fluorescence biological marker.
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Affiliation(s)
- Juan O Flores-Rizo
- Departamento de Quı́mica, Universidad de Guanajuato, Col. Noria Alta S/N, Guanajuato, Gto. 36050, Mexico
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27
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Zhai X, Momsen WE, Malakhov DA, Boldyrev IA, Momsen MM, Molotkovsky JG, Brockman HL, Brown RE. GLTP-fold interaction with planar phosphatidylcholine surfaces is synergistically stimulated by phosphatidic acid and phosphatidylethanolamine. J Lipid Res 2013; 54:1103-13. [PMID: 23369752 DOI: 10.1194/jlr.m034744] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Among amphitropic proteins, human glycolipid transfer protein (GLTP) forms a structurally-unique fold that translocates on/off membranes to specifically transfer glycolipids. Phosphatidylcholine (PC) bilayers with curvature-induced packing stress stimulate much faster glycolipid intervesicular transfer than nonstressed PC bilayers raising questions about planar cytosol-facing biomembranes being viable sites for GLTP interaction. Herein, GLTP-mediated desorption kinetics of fluorescent glycolipid (tetramethyl-boron dipyrromethene (BODIPY)-label) from lipid monolayers are assessed using a novel microfluidics-based surface balance that monitors lipid lateral packing while simultaneously acquiring surface fluorescence data. At biomembrane-like packing (30-35 mN/m), GLTP uptake of BODIPY-glycolipid from POPC monolayers was nearly nonexistent but could be induced by reducing surface pressure to mirror packing in curvature-stressed bilayers. In contrast, 1-palmitoyl-2-oleoyl-phosphatidylethanolamine (POPE) matrices supported robust BODIPY-glycolipid uptake by GLTP at both high and low surface pressures. Unexpectedly, negatively-charged cytosol-facing lipids, i.e., phosphatidic acid and phosphatidylserine, also supported BODIPY-glycolipid uptake by GLTP at high surface pressure. Remarkably, including both 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate (5 mol%) and POPE (15 mol%) in POPC synergistically activated GLTP at high surface pressure. Our study shows that matrix lipid headgroup composition, rather than molecular packing per se, is a key regulator of GLTP-fold function while demonstrating the novel capabilities of the microfluidics-based film balance for investigating protein-membrane interfacial interactions.
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Affiliation(s)
- Xiuhong Zhai
- The Hormel Institute, University of Minnesota, Austin, MN, USA
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28
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Yoshii R, Nagai A, Tanaka K, Chujo Y. Highly near-infrared emissive boron di(iso)indomethene-based polymer: Drastic change from deep-red to near-infrared emission via quantitative polymer reaction. ACTA ACUST UNITED AC 2013. [DOI: 10.1002/pola.26547] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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29
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Quan L, Chen Y, Lv XJ, Fu WF. Aggregation-Induced Photoluminescent Changes of Naphthyridine-BF2Complexes. Chemistry 2012; 18:14599-604. [DOI: 10.1002/chem.201201592] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Indexed: 11/10/2022]
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30
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Iehl J, Nierengarten JF, Harriman A, Bura T, Ziessel R. Artificial light-harvesting arrays: electronic energy migration and trapping on a sphere and between spheres. J Am Chem Soc 2011; 134:988-98. [PMID: 22148681 DOI: 10.1021/ja206894z] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
A sophisticated model of the natural light-harvesting antenna has been devised by decorating a C(60) hexa-adduct with ten yellow and two blue boron dipyrromethene (Bodipy) dyes in such a way that the dyes retain their individuality and assist solubility of the fullerene. Unusually, the fullerene core is a poor electron acceptor and does not enter into light-induced electron-transfer reactions with the appended dyes, but ineffective electronic energy transfer from the excited-state dye to the C(60) residue competes with fluorescence from the yellow dye. Intraparticle electronic energy transfer from yellow to blue dyes can be followed by steady-state and time-resolved fluorescence spectroscopy and by excitation spectra for isolated C(60) nanoparticles dissolved in dioxane at 293 K and at 77 K. The decorated particles can be loaded into polymer films by spin coating from solution. In the dried film, efficient energy transfer occurs such that photons absorbed by the yellow dye are emitted by the blue dye. Films can also be prepared to contain C(60) nanoparticles loaded with the yellow Bodipy dye but lacking the blue dye and, under these circumstances, electronic energy migration occurs between yellow dyes appended to the same nanoparticle and, at higher loading, to dye molecules on nearby particles. Doping these latter polymer films with the mixed-dye nanoparticle coalesces these multifarious processes in a single system. Thus, long-range energy migration occurs among yellow dyes attached to different particles before trapping at a blue dye. In this respect, the film resembles the natural photosynthetic light-harvesting complexes, albeit at much reduced efficacy. The decorated nanoparticles sensitize amorphous silicon photocells.
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Affiliation(s)
- Julien Iehl
- Laboratoire de Chimie des Matériaux Moléculaires, Université de Strasbourg et CNRS (UMR 7509), Ecole Européenne de Chimie, Polymères et Matériaux, 25 rue Becquerel, 67087 Strasbourg Cedex 02, France
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StarD7 behaves as a fusogenic protein in model and cell membrane bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1818:425-33. [PMID: 22063720 DOI: 10.1016/j.bbamem.2011.10.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 10/18/2011] [Accepted: 10/19/2011] [Indexed: 11/23/2022]
Abstract
StarD7 is a surface active protein, structurally related with the START lipid transport family. So, the present work was aimed at elucidating a potential mechanism of action for StarD7 that could be related to its interaction with a lipid-membrane interface. We applied an assay based on the fluorescence de-quenching of BD-HPC-labeled DMPC-DMPS 4:1 mol/mol SUVs (donor liposomes) induced by the dilution with non-labeled DMPC-DMPS 4:1 mol/mol LUVs (acceptor liposomes). Recombinant StarD7 accelerated the dilution of BD-HPC in a concentration-dependent manner. This result could have been explained by either a bilayer fusion or monomeric transport of the labeled lipid between donor and acceptor liposomes. Further experiments (fluorescence energy transfer between DPH-HPC/BD-HPC, liposome size distribution analysis by dynamic light scattering, and the multinuclear giant cell formation induced by recombinant StarD7) strongly indicated that bilayer fusion was the mechanism responsible for the StarD7-induced lipid dilution. The efficiency of lipid dilution was dependent on StarD7 electrostatic interactions with the lipid-water interface, as shown by the pH- and salt-induced modulation. Moreover, this process was favored by phosphatidylethanolamine which is known to stabilize non-lamellar phases considered as intermediary in the fusion process. Altogether these findings allow postulate StarD7 as a fusogenic protein.
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Araneda JF, Piers WE, Heyne B, Parvez M, McDonald R. High Stokes Shift Anilido-Pyridine Boron Difluoride Dyes. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201105228] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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33
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Araneda JF, Piers WE, Heyne B, Parvez M, McDonald R. High Stokes Shift Anilido-Pyridine Boron Difluoride Dyes. Angew Chem Int Ed Engl 2011; 50:12214-7. [DOI: 10.1002/anie.201105228] [Citation(s) in RCA: 224] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Indexed: 01/05/2023]
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Huang J, Zhu Z, Bamrungsap S, Zhu G, You M, He X, Wang K, Tan W. Competition-mediated pyrene-switching aptasensor: probing lysozyme in human serum with a monomer-excimer fluorescence switch. Anal Chem 2010; 82:10158-63. [PMID: 21080638 DOI: 10.1021/ac102277p] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Lysozyme (Lys) plays crucial roles in the innate immune system, and the detection of Lys in urine and serum has considerable clinical importance. Traditionally, the presence of Lys has been detected by immunoassays; however, these assays are limited by the availability of commercial antibodies and tedious protein modification and prior sample purification. To address these limitations, we report here the design, synthesis, and application of a competition-mediated pyrene-switching aptasensor for selective detection of Lys in buffer and human serum. The detection strategy is based on the attachment of pyrene molecules to both ends of a hairpin DNA strand, which becomes the partially complementary competitor to an anti-Lys aptamer. In the presence of target Lys, the aptamer hybridizes with part of the competitor, which opens the hairpin such that both pyrene molecules are spatially separated. In the presence of target Lys, however, the competitor is displaced from the aptamer by the target, subsequently forming an initial hairpin structure. This brings the two pyrene moieties into close proximity to generate an excimer, which, in turn, results in a shift of fluorescence emission from ca. 400 nm (pyrene monomer) to 495 nm (pyrene excimer). The proposed method for Lys detection showed sensitivity as low as 200 pM and high selectivity in buffer. When measured by a steady-state fluorescence spectrum, the detection of Lys in human serum showed a strong fluorescent background, which obscured detection of the excimer signal. However, time-resolved emission measurement (TREM) supported the potential of the method in complex environments with background fluorescence by demonstrating the temporal separation of probe fluorescence emission decay from the intense background signal. We have also demonstrated that the same strategy can be applied to the detection of small biomolecules such as adenosine triphosphate (ATP), showing the generality of our approach. Therefore, the competition-mediated pyrene-switching aptasensor is promising to have potential for clinical and forensic applications.
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Affiliation(s)
- Jin Huang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology and College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China
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Yoshii R, Nagai A, Chujo Y. Highly near-infrared photoluminescence from aza-borondipyrromethene-based conjugated polymers. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/pola.24335] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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36
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Taking another look with fluorescence microscopy: Image processing techniques in Langmuir monolayers for the twenty-first century. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:1289-300. [DOI: 10.1016/j.bbamem.2010.01.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 12/11/2009] [Accepted: 01/05/2010] [Indexed: 12/15/2022]
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37
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Ravasio A, Olmeda B, Bertocchi C, Haller T, Pérez-Gil J. Lamellar bodies form solid three-dimensional films at the respiratory air-liquid interface. J Biol Chem 2010; 285:28174-82. [PMID: 20558742 DOI: 10.1074/jbc.m110.106518] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Pulmonary surfactant is essential for lung function. It is assembled, stored and secreted as particulate entities (lamellar body-like particles; LBPs). LBPs disintegrate when they contact an air-liquid interface, leading to an instantaneous spreading of material and a decline in surface tension. Here, we demonstrate that the film formed by the adsorbed material spontaneously segregate into distinct ordered and disordered lipid phase regions under unprecedented near-physiological conditions and, unlike natural surfactant purified from bronchoalveolar lavages, dynamically reorganized into highly viscous multilayer domains with complex three-dimensional topographies. Multilayer domains, in coexistence with liquid phases, showed a progressive stiffening and finally solidification, probably driven by a self-driven disassembly of LBPs from a sub-surface compartment. We conclude that surface film formation from LBPs is a highly dynamic and complex process, leading to a more elaborated scenario than that observed and predicted by models using reconstituted, lavaged, or fractionated preparations.
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Affiliation(s)
- Andrea Ravasio
- Department of Physiology and Medical Physics, Medical University, 6020 Innsbruck, Austria
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Characterization of the lateral distribution of fluorescent lipid in binary-constituent lipid monolayers by principal component analysis. Int J Biomed Imaging 2010; 2010:125850. [PMID: 20414462 PMCID: PMC2857607 DOI: 10.1155/2010/125850] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Revised: 12/23/2009] [Accepted: 01/21/2010] [Indexed: 02/03/2023] Open
Abstract
Lipid lateral organization in binary-constituent monolayers consisting of fluorescent and nonfluorescent lipids has been investigated by acquiring multiple emission spectra during measurement of each force-area isotherm. The emission spectra reflect BODIPY-labeled lipid surface concentration and lateral mixing with different nonfluorescent lipid species. Using principal component analysis (PCA) each spectrum could be approximated as the linear combination of only two principal vectors. One point on a plane could be associated with each spectrum, where the coordinates of the point are the coefficients of the linear combination. Points belonging to the same lipid constituents and experimental conditions form a curve on the plane, where each point belongs to a different mole fraction. The location and shape of the curve reflects the lateral organization of the fluorescent lipid mixed with a specific nonfluorescent lipid. The method provides massive data compression that preserves and emphasizes key information pertaining to lipid distribution in different lipid monolayer phases. Collectively, the capacity of PCA for handling large spectral data sets, the nanoscale resolution afforded by the fluorescence signal, and the inherent versatility of monolayers for characterization of lipid lateral interactions enable significantly enhanced resolution of lipid lateral organizational changes induced by different lipid compositions.
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A nanometer scale optical view on the compartmentalization of cell membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:777-87. [DOI: 10.1016/j.bbamem.2009.09.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 09/13/2009] [Accepted: 09/20/2009] [Indexed: 12/30/2022]
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40
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Ermakov YA, Kamaraju K, Sengupta K, Sukharev S. Gadolinium ions block mechanosensitive channels by altering the packing and lateral pressure of anionic lipids. Biophys J 2010; 98:1018-27. [PMID: 20303859 PMCID: PMC2849073 DOI: 10.1016/j.bpj.2009.11.044] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 11/20/2009] [Accepted: 11/25/2009] [Indexed: 11/28/2022] Open
Abstract
Effects of polyvalent ions on the lateral packing of phospholipids have been known for decades, but the physiological consequences have not been systematically studied. Gd(3+) is a relatively nonspecific agent that blocks mechano-gated channels with a variable affinity. In this study, we show that the large mechanosensitive channel MscL of Escherichia coli is effectively blocked by Gd(3+) only when reconstituted with negatively charged phospholipids (e.g., PS). Taking this lead, we studied effects of Gd(3+) on monolayers and unilamellar vesicles made of natural brain PS, DMPS, and its mixtures with DMPC. In monolayer experiments, we found that muM Gd(3+) present in the subphase leads to approximately 8% lateral compaction of brain PS (at 35 mN/m). Gd(3+) more strongly shrinks and rigidifies DMPS films causing a spontaneous liquid expanded-to-compact transition to the limiting 40 A(2)/mol. Pressure-area isotherms of uncharged DMPC were unaffected by Gd(3+), and neutralization of DMPS surface by low pH did not produce strong compaction. Upshifts of surface potential isotherms of DMPS monolayers reflected changes in the diffuse double layer due to neutralization of headgroup charges by Gd(3+), whereas the increased packing density produced up to a 200 mV change in the interfacial dipole potential. The slopes of surface potential versus reciprocal area predicted that Gd(3+) induced a modest ( approximately 18%) increase in the magnitude of the individual lipid dipoles in DMPS. Isothermal titration calorimetry indicated that binding of Gd(3+) to DMPS liposomes in the gel state is endothermic, whereas binding to liquid crystalline liposomes produces heat consistent with the isothermal liquid-to-gel phase transition induced by the ion. Both titration curves suggested a K(b) of approximately 10(6) M(-1). We conclude that anionic phospholipids serve as high-affinity receptors for Gd(3+) ions, and the ion-induced compaction generates a lateral pressure increase estimated as tens of mN/m. This pressure can "squeeze" the channel and shift the equilibrium toward the closed state.
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Key Words
- dmpc, dimirystoyl phosphatidylcholine
- dmps, dimirystoyl phosphatidylserine
- edl, electric double layer
- gcs, gouy-chapman-stern approximation
- gd3+, gadolinium
- itc, isothermal titration calorimetry
- le-lc transition, liquid expanded–liquid compact transition
- mscl, mechanosensitive channel of large conductance
- mscs, mechanosensitive channel of small conductance
- pc, phosphatidylcholine
- pe, phosphatidylethanolamine
- ps, phosphatidylserine
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Affiliation(s)
- Yury A. Ermakov
- The Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow, Russia
| | - Kishore Kamaraju
- Department of Biology, University of Maryland, College Park, Maryland
| | - Krishnendu Sengupta
- Indian Association for the Cultivation of Sciences, Kolkata, West Bengal, India
| | - Sergei Sukharev
- Department of Biology, University of Maryland, College Park, Maryland
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41
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Lin IH, Meli MV, Abbott NL. Ordering transitions in micrometer-thick films of nematic liquid crystals driven by self-assembly of ganglioside GM1. J Colloid Interface Sci 2009; 336:90-9. [PMID: 19428021 PMCID: PMC2778293 DOI: 10.1016/j.jcis.2009.03.068] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Revised: 03/28/2009] [Accepted: 03/30/2009] [Indexed: 10/20/2022]
Abstract
We report an investigation of the self-assembly of the monosialoganglioside (GM(1)) at interfaces formed between aqueous solutions of 10 microM GM(1) (at 25 degrees C) and micrometer-thick films of the nematic liquid crystal (LC) 4'-pentyl-4-cyanobiphenyl (5CB). We observe the process of spontaneous transfer of GM(1) onto the interfaces to be accompanied by continuous ordering transitions within the micrometer-thick films of the LC. At saturation coverage, the GM(1) orders the LC in an orientation that is perpendicular to the interface, an orientation that is similar to that caused by phospholipids such as dilauroylphosphatidylcholine (DLPC). This result suggests an interaction between the LC and GM(1) that is dominated by the hydrophobic tails of the GM(1). Relative to DLPC, however, we observe the dynamics of the LC ordering transition driven by GM(1) to be slow (2 h for DLPC versus 100 h for GM(1)). To provide insight into the origins of the slow dynamics of the GM(1)-induced ordering transition in the LC, we performed two additional measurements. First, we quantified the time-dependent adsorption of GM(1) at the LC interface by using fluorescently-labeled GM(1). Second, we used the Langmuir-Schaefer method to transfer preorganized monolayers of GM(1) from an air-water interface to the aqueous-LC interface. Results obtained from these two experiments are consistent with a physical picture in which the final stages of spontaneous adsorption/ordering of GM(1) at the aqueous-LC interface dictate the dynamics of the LC ordering transition. This rate limiting process underlying the ordering transition was substantially accelerated by heating the system above the phase transition temperature of GM(1)(26 degrees C), suggesting that the phase state of the GM(1) micellar aggregates in bulk solution strongly influences the kinetics of the final stages of ordering/adsorption of GM(1) at the LC interface. Overall, these results and others presented in this manuscript reveal that it is possible to decorate interfaces of a nematic LC with GM(1), and that the assembly of GM(1) at these interfaces impacts the dynamic and equilibrium ordering of the LC.
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Affiliation(s)
- I-Hsin Lin
- Department of Chemical & Biological Engineering University of Wisconsin-Madison, 1415 Engineering Drive Madison, Wisconsin 53706
| | - Maria-Victoria Meli
- Department of Chemical & Biological Engineering University of Wisconsin-Madison, 1415 Engineering Drive Madison, Wisconsin 53706
| | - Nicholas L. Abbott
- Department of Chemical & Biological Engineering University of Wisconsin-Madison, 1415 Engineering Drive Madison, Wisconsin 53706
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42
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Kim S, Ohulchanskyy TY, Baev A, Prasad PN. Synthesis and nanoparticle encapsulation of 3,5-difuranylvinyl-boradiaza-s-indacenes for near-infrared fluorescence imaging. ACTA ACUST UNITED AC 2009. [DOI: 10.1039/b813396d] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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43
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Abstract
Routine quantitative analysis of biomolecule surface density by fluorescence microscopy has been limited by the difficulty of preparing appropriate calibration standards that relate measured fluorescence intensity to actual surface concentration. Supported lipid bilayers are planar fluid films of uniform density and composition which can incorporate a variety of lipidated fluorophores and work well as fluorescence standards. Here, we outline a straightforward strategy to calibrate digital micrographs of fluorescent surfaces such as planar cellular junctions for comparison to supported bilayer standards. It can be implemented with standard microscopy equipment. To illustrate the advantages of this approach, we quantify cell- and bilayer-side protein density patterns in a hybrid immunological synapse between a T-cell and a supported bilayer.
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44
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Johnson JM, Betz WJ. The color of lactotroph secretory granules stained with FM1-43 depends on dye concentration. Biophys J 2008; 94:3167-77. [PMID: 18065476 PMCID: PMC2275707 DOI: 10.1529/biophysj.107.112573] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Accepted: 11/15/2007] [Indexed: 11/18/2022] Open
Abstract
When pituitary lactotroph granules undergo exocytosis in the presence of FM1-43, their cores absorb dye and fluoresce brightly. We report that different granules fluoresce with different colors, despite being stained with a single fluorescent dye; emission spectra from individual granules show up to a 25 nm difference between the greenest and reddest granules. We found a correlation between granule color and average fluorescence intensity, suggesting that granule color depends upon dye concentration. We confirmed this in two ways: by increasing FM dye concentration in granules, which red shifted granule color, and by partially photobleaching the FM dye in granules, which green shifted granule color. Increasing stimulation intensity (by increasing KCl concentration) increased the proportion of red granules, indicating that granules exocytosing during intense stimulation bound more dye. This, perhaps, reflects differences in granule core maturation and condensation in which mature granules with condensed cores bind more FM dye but require more intense stimulation to be released. Concentration-dependent color shifts of FM dyes may be useful for monitoring aggregation processes occurring on a size scale smaller than the optical limit.
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Affiliation(s)
- Joseph M Johnson
- Department of Physiology and Biophysics, University of Colorado Medical School, Aurora, Colorado 80045, USA
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45
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Meli MV, Lin IH, Abbott NL. Preparation of microscopic and planar oil-water interfaces that are decorated with prescribed densities of insoluble amphiphiles. J Am Chem Soc 2008; 130:4326-33. [PMID: 18335929 DOI: 10.1021/ja077379a] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Langmuir monolayers (monolayers of insoluble molecules formed at the surface of water), and associated Langmuir-Blodgett/Schaefer monolayers prepared by transfer of Langmuir films to the surfaces of solids, are widely used in studies aimed at understanding the physicochemical properties of biological and synthetic molecules at interfaces. In this article, we report a general and facile procedure that permits transfer of Langmuir monolayers from the surface of water onto microscopic and planar interfaces between oil and aqueous phases. In these experiments, a metallic grid supported on a hydrophobic solid is used to form oil films with thicknesses of 20 mum and interfacial areas of 280 mum x 280 mum. Passage of the supported oil films through a Langmuir monolayer is shown to lead to quantitative transfer of insoluble amphiphiles onto the oil-water interfaces. The amphiphile-decorated oil-water interfaces hosted within the metallic grids (i) are approximately planar, (ii) are sufficiently robust mechanically so as to permit further characterization of the interfaces outside of the Langmuir trough, (iii) can be prepared with prescribed and well-defined densities of amphiphiles, and (iv) require only approximately 200 nL of oil to prepare. The utility of this method is illustrated for the case of the liquid crystalline oil 4-pentyl-4'-cyanobiphenyl (5CB). Transfer of monolayers of either dilauroyl- or dipalmitoylphosphatidylcholine (DLPC and DPPC, respectively) to the nematic 5CB-aqueous interface is demonstrated by epifluorescence imaging of fluorescently labeled lipid and polarized light imaging of the orientational order within the thin film of nematic 5CB. Interfaces prepared in this manner are used to reveal key differences between the density-dependent phase properties of DLPC and DPPC monolayers formed at air-water as compared to that of nematic 5CB-aqueous interfaces. The methodology described in this article should be broadly useful in advancing studies of the interfacial behavior of synthetic and biological molecules at liquid-liquid interfaces.
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Affiliation(s)
- Maria-Victoria Meli
- Department of Chemical & Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, Wisconsin, USA
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46
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Chen Y, Yang CJ, Wu Y, Conlon P, Kim Y, Lin H, Tan W. Light-Switching Excimer Beacon Assays For Ribonuclease H Kinetic Study. Chembiochem 2008; 9:355-9. [DOI: 10.1002/cbic.200700542] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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47
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Maggio B, Borioli GA, Del Boca M, De Tullio L, Fanani ML, Oliveira RG, Rosetti CM, Wilke N. Composition-driven surface domain structuring mediated by sphingolipids and membrane-active proteins. Above the nano- but under the micro-scale: mesoscopic biochemical/structural cross-talk in biomembranes. Cell Biochem Biophys 2007; 50:79-109. [PMID: 17968678 DOI: 10.1007/s12013-007-9004-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2007] [Indexed: 10/22/2022]
Abstract
Biomembranes contain a wide variety of lipids and proteins within an essentially two-dimensional structure. The coexistence of such a large number of molecular species causes local tensions that frequently relax into a phase or compositional immiscibility along the lateral and transverse planes of the interface. As a consequence, a substantial microheterogeneity of the surface topography develops and that depends not only on the lipid-protein composition, but also on the lateral and transverse tensions generated as a consequence of molecular interactions. The presence of proteins, and immiscibility among lipids, constitute major perturbing factors for the membrane sculpturing both in terms of its surface topography and dynamics. In this work, we will summarize some recent evidences for the involvement of membrane-associated, both extrinsic and amphitropic, proteins as well as membrane-active phosphohydrolytic enzymes and sphingolipids in driving lateral segregation of phase domains thus determining long-range surface topography.
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Affiliation(s)
- Bruno Maggio
- Departamento de Química Biológica, Facultad de Ciencias Químicas, Centro de Investigaciones en Química Biológica de Córdoba, Universidad Nacional de Córdoba - CONICET, Argentina.
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48
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Loudet A, Burgess K. BODIPY dyes and their derivatives: syntheses and spectroscopic properties. Chem Rev 2007; 107:4891-932. [PMID: 17924696 DOI: 10.1021/cr078381n] [Citation(s) in RCA: 3525] [Impact Index Per Article: 207.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Aurore Loudet
- Department of Chemistry, Texas A & M University, PO Box 30012, College Station, Texas 77842, USA
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49
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Li Z, Bittman R. Synthesis and spectral properties of cholesterol- and FTY720-containing boron dipyrromethene dyes. J Org Chem 2007; 72:8376-82. [PMID: 17914846 PMCID: PMC2547128 DOI: 10.1021/jo701475q] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two analogues (1, 2) of free cholesterol and one analogue (3) of the immunosuppressive sphingolipid FTY720 containing a boron dipyrromethene chromophore (BODIPY) were synthesized. The synthetic routes involved preparation of boron dipyrromethene moieties (5, 11), bearing a phenylethynyl group at different positions of the chromophore, and lipids (13, 20) bearing an azido group. The dye was tethered to the lipid via a 1,2,3-triazole in the linker by the click reaction. Analogues derived from 11 [in which an (E)-styrylethynyl moiety is bonded to C-5 of BODIPY] exhibited a marked red shift (approximately 70-80 nm) compared with those derived from 5 (in which a phenylethynyl moiety is bonded to C-8 of BODIPY).
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50
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Peña-Cabrera E, Aguilar-Aguilar A, Gonzalez-Domínguez M, Lager E, Zamudio-Vazquez R, Godoy-Vargas J, Villanueva-García F. Simple, General, and Efficient Synthesis of Meso-Substituted Borondipyrromethenes from a Single Platform. Org Lett 2007; 9:3985-8. [PMID: 17764191 DOI: 10.1021/ol7016615] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An unprecedented synthesis of 8-substituted-borondipyrromethenes is described starting from 8-thiomethylbodipy 1. Aryl, heteroaryl, alkenyl, and organometallic boronic acids smoothly reacted with 1 in the presence of a catalytic amount of Pd(0) and a stoichiometric amount of Cu(I)-2-thienylcarboxylate under neutral conditions to give the corresponding Bodipy analogues in good to quantitative yields (20 examples). A remarkable reactivity was observed in some cases, e.g., ferrocenylboronic acid gave the product in 98% isolated yield after only 10 min at 55 degrees C.
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Affiliation(s)
- Eduardo Peña-Cabrera
- Departamento de Química, Universidad de Guanajuato, Col. Noria Alta S/N, Guanajuato, Gto. 36050, Mexico.
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