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van den Noort M, Drougkas P, Paulino C, Poolman B. The substrate-binding domains of the osmoregulatory ABC importer OpuA transiently interact. eLife 2024; 12:RP90996. [PMID: 38695350 PMCID: PMC11065425 DOI: 10.7554/elife.90996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2024] Open
Abstract
Bacteria utilize various strategies to prevent internal dehydration during hypertonic stress. A common approach to countering the effects of the stress is to import compatible solutes such as glycine betaine, leading to simultaneous passive water fluxes following the osmotic gradient. OpuA from Lactococcus lactis is a type I ABC-importer that uses two substrate-binding domains (SBDs) to capture extracellular glycine betaine and deliver the substrate to the transmembrane domains for subsequent transport. OpuA senses osmotic stress via changes in the internal ionic strength and is furthermore regulated by the 2nd messenger cyclic-di-AMP. We now show, by means of solution-based single-molecule FRET and analysis with multi-parameter photon-by-photon hidden Markov modeling, that the SBDs transiently interact in an ionic strength-dependent manner. The smFRET data are in accordance with the apparent cooperativity in transport and supported by new cryo-EM data of OpuA. We propose that the physical interactions between SBDs and cooperativity in substrate delivery are part of the transport mechanism.
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Affiliation(s)
- Marco van den Noort
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of GroningenGroningenNetherlands
| | - Panagiotis Drougkas
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of GroningenGroningenNetherlands
- Biochemistry Center, Heidelberg UniversityHeidelbergGermany
| | - Cristina Paulino
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of GroningenGroningenNetherlands
- Biochemistry Center, Heidelberg UniversityHeidelbergGermany
| | - Bert Poolman
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of GroningenGroningenNetherlands
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2
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Wessig P, Lehmann M. [1,3]-Dioxolo[4,5-f]benzodioxole (DBD) Fluorescent Dyes; Synthesis, Properties, and Applications. SYNTHESIS-STUTTGART 2023. [DOI: 10.1055/s-0042-1751428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
AbstractIn this review we give an overview of the syntheses and photophysical properties of the new class of fluorescent dyes based on a [1,3]-dioxolo[4,5-f]benzodioxole core and their derivatives. Starting from commercially available reactants (e.g., sesamol, 1,2,4,5-tetrachlorobenzene) the core units can be prepared in a simple manner. Then, the benzene core can be derivatized via lithiation and their photophysical properties can be adjusted as desired. The obtained fluorophores have an absorption range of 403–520 nm and an emission range of 495–665 nm. This class of fluorescent dyes is also characterized by a long fluorescence lifetime, a high stability towards photobleaching, large Stokes shifts, and small size. Thus, the DBD dyes are optimally suited for optical sensing.1 Introduction2 Synthesis3 Properties4 Applications
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3
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Wessig P, John L, Sperlich E, Kelling A. Sulfur Tuning of [1,3]‐Dioxolo[4.5‐
f
]benzodioxole (DBD) Fluorescent Dyes. European J Org Chem 2021. [DOI: 10.1002/ejoc.202001418] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Pablo Wessig
- Institut für Chemie Universität Potsdam Karl-Liebknecht-Str. 24–25 14476 Potsdam Germany E-mail: ag-wessig.chem.uni-potsdam.de
| | - Leonard John
- Institut für Chemie Universität Potsdam Karl-Liebknecht-Str. 24–25 14476 Potsdam Germany E-mail: ag-wessig.chem.uni-potsdam.de
| | - Eric Sperlich
- Institut für Chemie Universität Potsdam Karl-Liebknecht-Str. 24–25 14476 Potsdam Germany E-mail: ag-wessig.chem.uni-potsdam.de
| | - Alexandra Kelling
- Institut für Chemie Universität Potsdam Karl-Liebknecht-Str. 24–25 14476 Potsdam Germany E-mail: ag-wessig.chem.uni-potsdam.de
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Marty MT. Nanodiscs and Mass Spectrometry: Making Membranes Fly. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 2020; 458:116436. [PMID: 33100891 PMCID: PMC7584149 DOI: 10.1016/j.ijms.2020.116436] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Cells are surrounded by a protective lipid bilayer membrane, and membrane proteins in the bilayer control the flow of chemicals, information, and energy across this barrier. Many therapeutics target membrane proteins, and some directly target the lipid membrane itself. However, interactions within biological membranes are challenging to study due to their heterogeneity and insolubility. Mass spectrometry (MS) has become a powerful technique for studying membrane proteins, especially how membrane proteins interact with their surrounding lipid environment. Although detergent micelles are the most common membrane mimetic, nanodiscs are emerging as a promising platform for MS. Nanodiscs, nanoscale lipid bilayers encircled by two scaffold proteins, provide a controllable lipid bilayer for solubilizing membrane proteins. This Young Scientist Perspective focuses on native MS of intact nanodiscs and highlights the unique experiments enabled by making membranes fly, including studying membrane protein-lipid interactions and exploring the specificity of fragile transmembrane peptide complexes. It will also explore current challenges and future perspectives for interfacing nanodiscs with MS.
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Affiliation(s)
- Michael T Marty
- Department of Chemistry and Biochemistry and Bio5 Institute, University of Arizona, Tucson, AZ 85721
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5
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Haubitz T, John L, Freyse D, Wessig P, Kumke MU. Investigating the Sulfur "Twist" on the Photophysics of DBD Dyes. J Phys Chem A 2020; 124:4345-4353. [PMID: 32392418 DOI: 10.1021/acs.jpca.0c01880] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The so-called DBD ([1,3]dioxolo[4,5-f][1,3]benzodioxole) dyes are a new class of fluorescent dyes, with tunable photophysical properties like absorption, fluorescence lifetime, and Stokes shift. With the development of sulfur based DBDs, this dye class is extended even further for possible applications in spectroscopy and microscopy. In this paper we are investigating the basic photophysical properties and their implications for future applications for S4-DBD as well as O4-DBD. On the basis of time-resolved laser fluorescence spectroscopy, transient absorption spectroscopy, and UV/vis-spectroscopy, we determined the rate constants of the radiative and nonradiative deactivation processes as well as the energy of respective electronic states involved in the electronic deactivation of S4-DBD and of O4-DBD. For S4-DBD we unraveled the triplet formation with intersystem crossing quantum yields of up to 80%. By TD-DFT calculations we estimated a triplet energy of around 13500-14700 cm-1 depending on the DBD dye and solvent. Through solvent dependent measurements, we found quadrupole moments in the range of 2 B.
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Affiliation(s)
- Toni Haubitz
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Strase 24-25, D-14476 Potsdam, Germany
| | - Leonard John
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Strase 24-25, D-14476 Potsdam, Germany
| | - Daniel Freyse
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Strase 24-25, D-14476 Potsdam, Germany
| | - Pablo Wessig
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Strase 24-25, D-14476 Potsdam, Germany
| | - Michael U Kumke
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Strase 24-25, D-14476 Potsdam, Germany
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6
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Wessig P, Freyse D, Schuster D, Kelling A. Fluorescent Dyes with Large Stokes Shifts Based on Benzo[1,2‐d:4,5‐d']bis([1,3]dithiole) (“S
4
‐DBD Dyes”). European J Org Chem 2020. [DOI: 10.1002/ejoc.202000093] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Pablo Wessig
- Institut für Chemie Universität Potsdam Karl‐Liebknecht‐Str. 24‐25 14476 Potsdam Germany
| | - Daniel Freyse
- Institut für Chemie Universität Potsdam Karl‐Liebknecht‐Str. 24‐25 14476 Potsdam Germany
| | - David Schuster
- Institut für Chemie Universität Potsdam Karl‐Liebknecht‐Str. 24‐25 14476 Potsdam Germany
| | - Alexandra Kelling
- Institut für Chemie Universität Potsdam Karl‐Liebknecht‐Str. 24‐25 14476 Potsdam Germany
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Mächtel R, Narducci A, Griffith DA, Cordes T, Orelle C. An integrated transport mechanism of the maltose ABC importer. Res Microbiol 2019; 170:321-337. [PMID: 31560984 PMCID: PMC6906923 DOI: 10.1016/j.resmic.2019.09.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 09/10/2019] [Accepted: 09/13/2019] [Indexed: 12/27/2022]
Abstract
ATP-binding cassette (ABC) transporters use the energy of ATP hydrolysis to transport a large diversity of molecules actively across biological membranes. A combination of biochemical, biophysical, and structural studies has established the maltose transporter MalFGK2 as one of the best characterized proteins of the ABC family. MalF and MalG are the transmembrane domains, and two MalKs form a homodimer of nucleotide-binding domains. A periplasmic maltose-binding protein (MalE) delivers maltose and other maltodextrins to the transporter, and triggers its ATPase activity. Substrate import occurs in a unidirectional manner by ATP-driven conformational changes in MalK2 that allow alternating access of the substrate-binding site in MalF to each side of the membrane. In this review, we present an integrated molecular mechanism of the transport process considering all currently available information. Furthermore, we summarize remaining inconsistencies and outline possible future routes to decipher the full mechanistic details of transport by MalEFGK2 complex and that of related importer systems.
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Affiliation(s)
- Rebecca Mächtel
- Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Großhadernerstr. 2-4, 82152 Planegg-Martinsried, Germany
| | - Alessandra Narducci
- Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Großhadernerstr. 2-4, 82152 Planegg-Martinsried, Germany
| | - Douglas A Griffith
- Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Großhadernerstr. 2-4, 82152 Planegg-Martinsried, Germany
| | - Thorben Cordes
- Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Großhadernerstr. 2-4, 82152 Planegg-Martinsried, Germany.
| | - Cédric Orelle
- Université de Lyon, CNRS, UMR5086 "Molecular Microbiology and Structural Biochemistry", IBCP, 7 passage du Vercors, 69367 Lyon, France.
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8
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Regulation of arginine biosynthesis, catabolism and transport in Escherichia coli. Amino Acids 2019; 51:1103-1127. [DOI: 10.1007/s00726-019-02757-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 06/27/2019] [Indexed: 11/26/2022]
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9
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Haubitz T, John L, Wessig P, Kumke MU. Photophysics of Acyl- and Ester-DBD Dyes: Quadrupole-Induced Solvent Relaxation Investigated by Transient Absorption Spectroscopy. J Phys Chem A 2019; 123:4717-4726. [PMID: 31067057 DOI: 10.1021/acs.jpca.9b02973] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A new generation of wavelength-tunable, fluorescent dyes, so-called DBD ([1,3]dioxolo[4,5- f][1,3]benzodioxole) dyes, were developed a few years ago, and they showed great potential as probes, for example, for fluorescence microscopy. However, their photophysics is not fully explored and leaves open questions regarding their large fluorescence Stokes shifts and sensitivity to solvent conditions of differently substituted DBD dyes. To improve the understanding of the influence of the substitution pattern of the DBD dyes on their respective photophysics, transient absorption spectroscopy (TAS) was used, that is, a pump-probe experiment on the femtosecond timescale. TAS allows measurements of excited states, ground state recovery, solvent relaxation, and fluorescence properties on time scales of up to several nanoseconds. Two different DBD dye samples were investigated: acyl- and ester-substituted DBD dyes. Experiments were carried out in solvents with different polarities using different excitation energies and at different viscosities. Based on the experimental data and theoretical calculations, we were able to determine the conformational changes of the molecule due to electronic excitation and were able to investigate solvent relaxation processes for both types of DBD dyes. By generalizing the theory for quadrupole-induced solvent relaxation developed by Togashi et al., we derived quadrupole moments of both molecules in the ground and excited state. Our data showed differences in the binding of polar solvent molecules to the dyes depending on the substituent on the DBD dye. In the case of water as the solvent, an additional efficient quenching process in the electronically excited state was revealed, which was indicated by the observation of solvated electrons in the TAS signals.
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Affiliation(s)
- Toni Haubitz
- Institute of Chemistry , University of Potsdam , Karl-Liebknecht-Str. 24-25 , D-14476 Potsdam , Germany
| | - Leonard John
- Institute of Chemistry , University of Potsdam , Karl-Liebknecht-Str. 24-25 , D-14476 Potsdam , Germany
| | - Pablo Wessig
- Institute of Chemistry , University of Potsdam , Karl-Liebknecht-Str. 24-25 , D-14476 Potsdam , Germany
| | - Michael U Kumke
- Institute of Chemistry , University of Potsdam , Karl-Liebknecht-Str. 24-25 , D-14476 Potsdam , Germany
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10
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Nolting D, Malek R, Makarov A. Ion traps in modern mass spectrometry. MASS SPECTROMETRY REVIEWS 2019; 38:150-168. [PMID: 29084367 DOI: 10.1002/mas.21549] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 09/19/2017] [Indexed: 06/07/2023]
Abstract
This review is devoted to trapping mass spectrometry wherein ions are confined by electromagnetic fields for prolonged periods of time within limited volume, with mass measurement taking place within the same volume. Three major types of trapping mass spectrometers are discussed, specifically radiofrequency ion trap, Fourier transform ion cyclotron resonance and Orbitrap. While these three branches are intricately interwoven with each other over their recent history, they also differ greatly in their fundamentals, roots and historical origin. This diversity is reflected also in the difference of viewpoints from which each of these directions is addressed in this review. Following the theme of the issue, we focus on developments mainly associated with the country of Germany but, at the same time, we use this review as an illustration of the rapidly increasing globalization of science and expanding multi-national collaborations.
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11
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Evidence from Mutational Analysis for a Single Transmembrane Substrate Binding Site in the Histidine ATP-Binding Cassette Transporter of Salmonella enterica Serovar Typhimurium. J Bacteriol 2018; 201:JB.00521-18. [PMID: 30348830 DOI: 10.1128/jb.00521-18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/14/2018] [Indexed: 11/20/2022] Open
Abstract
The histidine ATP-binding cassette (ABC) transporter of Salmonella enterica serovar Typhimurium is among the best-studied type I ABC import systems. The transporter consists of two transmembrane subunits, HisQ and HisM, and a homodimer of the nucleotide-binding subunit, HisP. Substrates are delivered by two periplasmic solute binding proteins, HisJ and LAO, with preferences for histidine and for lysine, arginine, and ornithine, respectively. A homology model was built by using the arginine-bound crystal structure of the closely related Art(QN)2 transporter of Thermoanaerobacter tengcongensis as the template. In the homodimeric Art(QN)2, one substrate molecule is bound to each of the ArtQ subunits, whereas the structural model and sequence alignments predict only one substrate molecule in contact with HisM. To address the question whether one or two binding sites exist in heterodimeric HisQM, we have studied the functional consequences of mutations by monitoring (i) the complementation of growth on d-histidine of auxotrophic tester strains, (ii) the growth of tester strains on arginine as a nitrogen source, and (iii) ATPase activity of purified variants in a lipid environment. Our results demonstrate that two negatively charged residues, namely, HisM-E166 and HisQ-D61, are indispensable for function. Furthermore, the complete reconstruction of an ArtQ-like binding site in HisQ resulted in an inactive transporter. Likewise, switching the positions of both negatively charged residues between HisQ and HisM caused transport-deficient phenotypes. Thus, we propose that one substrate molecule is primarily liganded by residues of HisM while HisQ-D61 forms a crucial salt bridge with the α-amino group of the substrate.IMPORTANCE Canonical ATP-binding cassette (ABC) importers are major players in the translocation of numerous nutrients, vitamins, and growth factors to the cytoplasm of prokaryotes. Moreover, some ABC importers have been identified as virulence factors in bacterial pathogenesis. Thus, a full understanding of their mode of action is considered a prerequisite, among others, for the development of novel antibacterial drugs. However, mainly owing to the lack of structural information, the knowledge of the chemical nature and number of substrate binding sites formed by the transmembrane subunits of ABC importers is scarce. Here, we provide evidence from mutational analyses that, in contrast to homologous homodimeric systems, the heterodimeric histidine transporter of Salmonella enterica serovar Typhimurium is liganding only one substrate molecule between its transmembrane subunits, HisM and HisQ.
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12
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Wessig P, John L, Mertens M. Extending the Class of [1,3]-Dioxolo[4.5-f]benzodioxole (DBD) Fluorescent Dyes. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Pablo Wessig
- Institut für Chemie; Universität Potsdam; Karl-Liebknecht-Str. 24-25 14476 Potsdam Germany
| | - Leonard John
- Institut für Chemie; Universität Potsdam; Karl-Liebknecht-Str. 24-25 14476 Potsdam Germany
| | - Monique Mertens
- Institut für Chemie; Universität Potsdam; Karl-Liebknecht-Str. 24-25 14476 Potsdam Germany
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13
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Schwarze T, Mertens M, Müller P, Riemer J, Wessig P, Holdt HJ. Highly K + -Selective Fluorescent Probes for Lifetime Sensing of K + in Living Cells. Chemistry 2017; 23:17186-17190. [PMID: 28895214 DOI: 10.1002/chem.201703799] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Indexed: 12/16/2022]
Abstract
The new K+ -selective fluorescent probes 1 and 2 were obtained by CuI -catalyzed 1,3-dipolar azide alkyne cycloaddition (CuAAC) reactions of an alkyne-substituted [1,3]dioxolo[4,5-f][1,3]benzodioxole (DBD) ester fluorophore with azido-functionalized N-phenylaza-18-crown-6 ether and N-(o-isopropoxy) phenylaza-18-crown-6 ether, respectively. Probes 1 and 2 allow the detection of K+ in the presence of Na+ in water by fluorescence enhancement (2.2 for 1 at 2000 mm K+ and 2.5 for 2 at 160 mm K+ ). Fluorescence lifetime measurements in the absence and presence of K+ revealed bi-exponential decay kinetics with similar lifetimes, however with different proportions changing the averaged fluorescence decay times (τf(av) ). For 1 a decrease of τf(av) from 12.4 to 9.3 ns and for 2 an increase from 17.8 to 21.8 ns was observed. Variation of the substituent in ortho position of the aniline unit of the N-phenylaza-18-crown-6 host permits the modulation of the Kd value for a certain K+ concentration. For example, substitution of H in 1 by the isopropoxy group (2) decreased the Kd value from >300 mm to 10 mm. 2 was chosen for studying the efflux of K+ from human red blood cells (RBC). Upon addition of the Ca2+ ionophor ionomycin to a RBC suspension in a buffer containing Ca2+ , the fluorescence of 2 slightly rose within 10 min, however, after 120 min a significant increase was observed.
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Affiliation(s)
- Thomas Schwarze
- Institut für Chemie, Anorganische Chemie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Golm, Germany
| | - Monique Mertens
- Institut für Chemie, Bioorganische Chemie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Golm, Germany
| | - Peter Müller
- Institut für Biologie/Molekulare Biophysik, Humboldt Universität zu Berlin, Invalidenstr. 42, 10115, Berlin, Germany
| | - Janine Riemer
- Institut für Chemie, Anorganische Chemie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Golm, Germany
| | - Pablo Wessig
- Institut für Chemie, Bioorganische Chemie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Golm, Germany
| | - Hans-Jürgen Holdt
- Institut für Chemie, Anorganische Chemie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Golm, Germany
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Homburg C, Bommer M, Wuttge S, Hobe C, Beck S, Dobbek H, Deutscher J, Licht A, Schneider E. Inducer exclusion in Firmicutes: insights into the regulation of a carbohydrate ATP binding cassette transporter from Lactobacillus casei BL23 by the signal transducing protein P-Ser46-HPr. Mol Microbiol 2017; 105:25-45. [PMID: 28370477 DOI: 10.1111/mmi.13680] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/26/2017] [Indexed: 12/24/2022]
Abstract
Catabolite repression is a mechanism that enables bacteria to control carbon utilization. As part of this global regulatory network, components of the phosphoenolpyruvate:carbohydrate phosphotransferase system inhibit the uptake of less favorable sugars when a preferred carbon source such as glucose is available. This process is termed inducer exclusion. In bacteria belonging to the phylum Firmicutes, HPr, phosphorylated at serine 46 (P-Ser46-HPr) is the key player but its mode of action is elusive. To address this question at the level of purified protein components, we have chosen a homolog of the Escherichia coli maltose/maltodextrin ATP-binding cassette transporter from Lactobacillus casei (MalE1-MalF1G1K12 ) as a model system. We show that the solute binding protein, MalE1, binds linear and cyclic maltodextrins but not maltose. Crystal structures of MalE1 complexed with these sugars provide a clue why maltose is not a substrate. P-Ser46-HPr inhibited MalE1/maltotetraose-stimulated ATPase activity of the transporter incorporated in proteoliposomes. Furthermore, cross-linking experiments revealed that P-Ser46-HPr contacts the nucleotide-binding subunit, MalK1, in proximity to the Walker A motif. However, P-Ser46-HPr did not block binding of ATP to MalK1. Together, our findings provide first biochemical evidence that P-Ser-HPr arrests the transport cycle by preventing ATP hydrolysis at the MalK1 subunits of the transporter.
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Affiliation(s)
- Constanze Homburg
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Martin Bommer
- Institut für Biologie/Strukturbiologie und Biochemie, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Steven Wuttge
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Carolin Hobe
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Sebastian Beck
- Institut für Chemie/Angewandte Analytik und Umweltchemie, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Holger Dobbek
- Institut für Biologie/Strukturbiologie und Biochemie, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Josef Deutscher
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, F-78350, France.,Expression Génétique Microbienne, Institut de Biologie Physico-Chimique, Centre National de la Recherche Scientifique, UMR8261, Paris, F-75005, France
| | - Anke Licht
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
| | - Erwin Schneider
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Berlin, D-10099, Germany
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Abstract
Membrane proteins play a most important part in metabolism, signaling, cell motility, transport, development, and many other biochemical and biophysical processes which constitute fundamentals of life on the molecular level. Detailed understanding of these processes is necessary for the progress of life sciences and biomedical applications. Nanodiscs provide a new and powerful tool for a broad spectrum of biochemical and biophysical studies of membrane proteins and are commonly acknowledged as an optimal membrane mimetic system that provides control over size, composition, and specific functional modifications on the nanometer scale. In this review we attempted to combine a comprehensive list of various applications of nanodisc technology with systematic analysis of the most attractive features of this system and advantages provided by nanodiscs for structural and mechanistic studies of membrane proteins.
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Affiliation(s)
- Ilia G Denisov
- Department of Biochemistry and Department of Chemistry, University of Illinois , Urbana, Illinois 61801, United States
| | - Stephen G Sligar
- Department of Biochemistry and Department of Chemistry, University of Illinois , Urbana, Illinois 61801, United States
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16
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Wessig P, Behrends N, Kumke MU, Eisold U. FRET Pairs with Fixed Relative Orientation of Chromophores. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600489] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Pablo Wessig
- Institut für Chemie; Universität Potsdam; Karl-Liebknecht-Str. 24-25 14476 Potsdam Germany
| | - Nicole Behrends
- Institut für Chemie; Universität Potsdam; Karl-Liebknecht-Str. 24-25 14476 Potsdam Germany
| | - Michael U. Kumke
- Institut für Chemie; Universität Potsdam; Karl-Liebknecht-Str. 24-25 14476 Potsdam Germany
| | - Ursula Eisold
- Institut für Chemie; Universität Potsdam; Karl-Liebknecht-Str. 24-25 14476 Potsdam Germany
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17
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Wessig P, Behrends N, Kumke MU, Eisold U, Meiling T, Hille C. Two-photon FRET pairs based on coumarin and DBD dyes. RSC Adv 2016. [DOI: 10.1039/c6ra03983a] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Synthesis and photophysical properties of coumarin–DBD FRET pairs, which are also suitable for two-photon excitation and fluorescence-lifetime imaging microscopy.
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Affiliation(s)
- P. Wessig
- Institut für Chemie
- Universität Potsdam
- 14476 Potsdam
- Germany
| | - N. Behrends
- Institut für Chemie
- Universität Potsdam
- 14476 Potsdam
- Germany
| | - M. U. Kumke
- Institut für Chemie
- Universität Potsdam
- 14476 Potsdam
- Germany
| | - U. Eisold
- Institut für Chemie
- Universität Potsdam
- 14476 Potsdam
- Germany
| | - T. Meiling
- Institut für Chemie
- Universität Potsdam
- 14476 Potsdam
- Germany
| | - C. Hille
- Institut für Chemie
- Universität Potsdam
- 14476 Potsdam
- Germany
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18
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Finkenwirth F, Sippach M, Landmesser H, Kirsch F, Ogienko A, Grunzel M, Kiesler C, Steinhoff HJ, Schneider E, Eitinger T. ATP-dependent Conformational Changes Trigger Substrate Capture and Release by an ECF-type Biotin Transporter. J Biol Chem 2015; 290:16929-42. [PMID: 25991724 DOI: 10.1074/jbc.m115.654343] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Indexed: 11/06/2022] Open
Abstract
Energy-coupling factor (ECF) transporters for vitamins and metal ions in prokaryotes consist of two ATP-binding cassette-type ATPases, a substrate-specific transmembrane protein (S component) and a transmembrane protein (T component) that physically interacts with the ATPases and the S component. The mechanism of ECF transporters was analyzed upon reconstitution of a bacterial biotin transporter into phospholipid bilayer nanodiscs. ATPase activity was not stimulated by biotin and was only moderately reduced by vanadate. A non-hydrolyzable ATP analog was a competitive inhibitor. As evidenced by cross-linking of monocysteine variants and by site-specific spin labeling of the Q-helix followed by EPR-based interspin distance analyses, closure and reopening of the ATPase dimer (BioM2) was a consequence of ATP binding and hydrolysis, respectively. A previously suggested role of a stretch of small hydrophobic amino acid residues within the first transmembrane segment of the S units for S unit/T unit interactions was structurally and functionally confirmed for the biotin transporter. Cross-linking of this segment in BioY (S) using homobifunctional thiol-reactive reagents to a coupling helix of BioN (T) indicated a reorientation rather than a disruption of the BioY/BioN interface during catalysis. Fluorescence emission of BioY labeled with an environmentally sensitive fluorophore was compatible with an ATP-induced reorientation and consistent with a hypothesized toppling mechanism. As demonstrated by [(3)H]biotin capture assays, ATP binding stimulated substrate capture by the transporter, and subsequent ATP hydrolysis led to substrate release. Our study represents the first experimental insight into the individual steps during the catalytic cycle of an ECF transporter in a lipid environment.
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Affiliation(s)
| | - Michael Sippach
- the Fachbereich Physik, Universität Osnabrück, Barbarastrasse 7, 49076 Osnabrück, Germany
| | - Heidi Landmesser
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Chausseestrasse 117, 10115 Berlin, Germany and
| | | | | | | | | | - Heinz-Jürgen Steinhoff
- the Fachbereich Physik, Universität Osnabrück, Barbarastrasse 7, 49076 Osnabrück, Germany
| | - Erwin Schneider
- Institut für Biologie/Physiologie der Mikroorganismen, Humboldt-Universität zu Berlin, Chausseestrasse 117, 10115 Berlin, Germany and
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19
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Structural basis for substrate specificity of an amino acid ABC transporter. Proc Natl Acad Sci U S A 2015; 112:5243-8. [PMID: 25848002 DOI: 10.1073/pnas.1415037112] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
ATP-binding cassette (ABC) transporters are ubiquitous integral membrane proteins that translocate a variety of substrates, ranging from ions to macromolecules, either out of or into the cytosol (hence defined as importers or exporters, respectively). It has been demonstrated that ABC exporters and importers function through a common mechanism involving conformational switches between inward-facing and outward-facing states; however, the mechanism underlying their functions, particularly substrate recognition, remains elusive. Here we report the structures of an amino acid ABC importer Art(QN)2 from Thermoanaerobacter tengcongensis composed of homodimers each of the transmembrane domain ArtQ and the nucleotide-binding domain ArtN, either in its apo form or in complex with substrates (Arg, His) and/or ATPs. The structures reveal that the straddling of the TMDs around the twofold axis forms a substrate translocation pathway across the membrane. Interestingly, each TMD has a negatively charged pocket that together create a negatively charged internal tunnel allowing amino acids carrying positively charged groups to pass through. Our structural and functional studies provide a better understanding of how ABC transporters select and translocate their substrates.
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20
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Sippach M, Weidlich D, Klose D, Abé C, Klare J, Schneider E, Steinhoff HJ. Conformational changes of the histidine ATP-binding cassette transporter studied by double electron-electron resonance spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:1760-8. [PMID: 24583084 DOI: 10.1016/j.bbamem.2014.02.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 02/06/2014] [Accepted: 02/18/2014] [Indexed: 10/25/2022]
Abstract
The conformational dynamics of the histidine ABC transporter HisQMP2 from Salmonella enterica serovar Typhimurium, reconstituted into liposomes, is studied by site-directed spin labeling and double electron-electron resonance spectroscopy in the absence of nucleotides, in the ATP-bound, and in the post-hydrolysis state. The results show that the inter-dimer distances as measured between the Q-loops of HisP2 in the intact transporter resemble those determined for the maltose transporter in all three states of the hydrolysis cycle. Only in the presence of liganded HisJ the closed conformation of the nucleotide binding sites is achieved revealing the transmembrane communication of the presence of substrate. Two conformational states can be distinguished for the periplasmic moiety of HisQMP2 as detected by differences in distributions of interspin distances between positions 86 and 96 or 104 and 197. The observed conformational changes are correlated to proposed open, semi-open and closed conformations of the nucleotide binding domains HisP2. Our results are in line with a rearrangement of transmembrane helices 4 and 4' of HisQM during the closed to the semi-open transition of HisP2 driven by the reorientation of the coupled helices 3a and 3b to occur upon hydrolysis.
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Affiliation(s)
- Michael Sippach
- Fachbereich Physik, Universität Osnabrück, Barbarastr.7, 49076 Osnabrück, Germany
| | - Daniela Weidlich
- Institut für Biologie, AG Bakterienphysiologie, Humboldt Universität zu Berlin, Chausseestr. 117, D-10115 Berlin, Germany
| | - Daniel Klose
- Fachbereich Physik, Universität Osnabrück, Barbarastr.7, 49076 Osnabrück, Germany
| | - Christoph Abé
- Fachbereich Physik, Universität Osnabrück, Barbarastr.7, 49076 Osnabrück, Germany
| | - Johann Klare
- Fachbereich Physik, Universität Osnabrück, Barbarastr.7, 49076 Osnabrück, Germany
| | - Erwin Schneider
- Institut für Biologie, AG Bakterienphysiologie, Humboldt Universität zu Berlin, Chausseestr. 117, D-10115 Berlin, Germany
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