1
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Zurlo E, Kumar P, Meisl G, Dear AJ, Mondal D, Claessens MMAE, Knowles TPJ, Huber M. In situ kinetic measurements of α-synuclein aggregation reveal large population of short-lived oligomers. PLoS One 2021; 16:e0245548. [PMID: 33481908 PMCID: PMC7822277 DOI: 10.1371/journal.pone.0245548] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 01/04/2021] [Indexed: 11/19/2022] Open
Abstract
Knowledge of the mechanisms of assembly of amyloid proteins into aggregates is of central importance in building an understanding of neurodegenerative disease. Given that oligomeric intermediates formed during the aggregation reaction are believed to be the major toxic species, methods to track such intermediates are clearly needed. Here we present a method, electron paramagnetic resonance (EPR), by which the amount of intermediates can be measured over the course of the aggregation, directly in the reacting solution, without the need for separation. We use this approach to investigate the aggregation of α-synuclein (αS), a synaptic protein implicated in Parkinson’s disease and find a large population of oligomeric species. Our results show that these are primary oligomers, formed directly from monomeric species, rather than oligomers formed by secondary nucleation processes, and that they are short-lived, the majority of them dissociates rather than converts to fibrils. As demonstrated here, EPR offers the means to detect such short-lived intermediate species directly in situ. As it relies only on the change in size of the detected species, it will be applicable to a wide range of self-assembling systems, making accessible the kinetics of intermediates and thus allowing the determination of their rates of formation and conversion, key processes in the self-assembly reaction.
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Affiliation(s)
- Enrico Zurlo
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Leiden, The Netherlands
| | - Pravin Kumar
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Leiden, The Netherlands
| | - Georg Meisl
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, United Kingdom
| | - Alexander J. Dear
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, United Kingdom
| | - Dipro Mondal
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Leiden, The Netherlands
| | | | - Tuomas P. J. Knowles
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, United Kingdom
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Martina Huber
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Leiden, The Netherlands
- * E-mail:
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2
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Burger M, Rein S, Weber S, Gräber P, Kacprzak S. Distance measurements in the F 0F 1-ATP synthase from E. coli using smFRET and PELDOR spectroscopy. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2019; 49:1-10. [PMID: 31705179 DOI: 10.1007/s00249-019-01408-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/09/2019] [Accepted: 10/29/2019] [Indexed: 12/12/2022]
Abstract
Fluorescence resonance energy transfer in single enzyme molecules (smFRET, single-molecule measurement) allows the measurement of multicomponent distance distributions in complex biomolecules similar to pulsed electron-electron double resonance (PELDOR, ensemble measurement). Both methods use reporter groups: FRET exploits the distance dependence of the electric interaction between electronic transition dipole moments of the attached fluorophores, whereas PELDOR spectroscopy uses the distance dependence of the interaction between the magnetic dipole moments of attached spin labels. Such labels can be incorporated easily to cysteine residues in the protein. Comparison of distance distributions obtained with both methods was carried out with the H+-ATPase from Escherichia coli (EF0F1). The crystal structure of this enzyme is known. It contains endogenous cysteines, and as an internal reference two additional cysteines were introduced (EF0F1-γT106C-εH56C). These positions were chosen to allow application of both methods under optimal conditions. Both methods yield very similar multicomponent distance distributions. The dominating distance distribution (> 50%) is due to the two cysteines introduced by site-directed mutagenesis and the distance is in agreement with the crystal structure. Two additional distance distributions are detected with smFRET and with PELDOR. These can be assigned by comparison with the structure to labels at endogenous cysteines. One additional distribution is detected only with PELDOR. The comparison indicates that under optimal conditions smFRET and PELDOR result in the same distance distributions. PELDOR has the advantage that different distributions can be obtained with ensemble measurements, whereas FRET requires single-molecule techniques.
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Affiliation(s)
- Markus Burger
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Stephan Rein
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Stefan Weber
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
| | - Peter Gräber
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany.
| | - Sylwia Kacprzak
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104, Freiburg, Germany
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3
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Kumar P, van Son M, Zheng T, Valdink D, Raap J, Kros A, Huber M. Coiled-coil formation of the membrane-fusion K/E peptides viewed by electron paramagnetic resonance. PLoS One 2018; 13:e0191197. [PMID: 29351320 PMCID: PMC5774749 DOI: 10.1371/journal.pone.0191197] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 12/29/2017] [Indexed: 11/18/2022] Open
Abstract
The interaction of the complementary K (Ac-(KIAALKE)3-GW-NH2) and E (Ac-(EIAALEK)3-GY-NH2) peptides, components of the zipper of an artificial membrane fusion system (Robson Marsden H. et al. Angew Chemie Int Ed. 2009) is investigated by electron paramagnetic resonance (EPR). By frozen solution continuous-wave EPR and double electron-electron resonance (DEER), the distance between spin labels attached to the K- and to the E-peptide is measured. Three constructs of spin-labelled K- and E-peptides are used in five combinations for low temperature investigations. The K/E heterodimers are found to be parallel, in agreement with previous studies. Also, K homodimers in parallel orientation were observed, a finding that was not reported before. Comparison to room-temperature, solution EPR shows that the latter method is less specific to detect this peptide-peptide interaction. Combining frozen solution cw-EPR for short distances (1.8 nm to 2.0 nm) and DEER for longer distances thus proves versatile to detect the zipper interaction in membrane fusion. As the methodology can be applied to membrane samples, the approach presented suggests itself for in-situ studies of the complete membrane fusion process, opening up new avenues for the study of membrane fusion.
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Affiliation(s)
- Pravin Kumar
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Leiden, The Netherlands
| | - Martin van Son
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Leiden, The Netherlands
| | - Tingting Zheng
- Department of Supramolecular and Biomaterials Chemistry, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Dayenne Valdink
- Department of Supramolecular and Biomaterials Chemistry, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Jan Raap
- Department of Supramolecular and Biomaterials Chemistry, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Alexander Kros
- Department of Supramolecular and Biomaterials Chemistry, Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - Martina Huber
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Leiden, The Netherlands
- * E-mail:
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4
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Kumar P, Schilderink N, Subramaniam V, Huber M. Membrane Binding of Parkinson's Protein α-Synuclein: Effect of Phosphorylation at Positions 87 and 129 by the S to D Mutation Approach. Isr J Chem 2017; 57:762-770. [PMID: 28919642 PMCID: PMC5573911 DOI: 10.1002/ijch.201600083] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Indexed: 11/10/2022]
Abstract
Human α-synuclein, a protein relevant in the brain with so-far unknown function, plays an important role in Parkinson's disease. The phosphorylation state of αS was related to the disease, prompting interest in this process. The presumed physiological function and the disease action of αS involves membrane interaction. Here, we study the effect of phosphorylation at positions 87 and 129, mimicked by the mutations S87A, S129A (nonphosphorylated) and S87D, S129D (phosphorylated) on membrane binding. Local binding is detected by spin-label continuous-wave electron paramagnetic resonance. For S87A/D, six positions (27, 56, 63, 69, 76, and 90) are probed; and for S129A/D, three (27, 56, and 69). Binding to large unilamellar vesicles of 100 nm diameter of 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine in a 1 : 1 composition is not affected by the phosphorylation state of S129. For phosphorylation at S87, local unbinding of αS from the membrane is observed. We speculate that modulating the local membrane affinity by phosphorylation could tune the way αS interacts with different membranes; for example, tuning its membrane fusion activity.
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Affiliation(s)
- Pravin Kumar
- Department of Physics, Huygens-Kamerlingh-Onnes LaboratoryLeiden UniversityLeidenThe Netherlands
| | - Nathalie Schilderink
- Nanobiophysics, MESA+ Institute for NanotechnologyUniversity of TwenteEnschedeThe Netherlands
| | - Vinod Subramaniam
- Nanobiophysics, MESA+ Institute for NanotechnologyUniversity of TwenteEnschedeThe Netherlands
- FOM Institute AMOLFAmsterdamThe Netherlands
- Vrije Universiteit of AmsterdamAmsterdamThe Netherlands
| | - Martina Huber
- Department of Physics, Huygens-Kamerlingh-Onnes LaboratoryLeiden UniversityLeidenThe Netherlands
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5
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Interaction of the amyloid β peptide with sodium dodecyl sulfate as a membrane-mimicking detergent. J Biol Phys 2016; 42:299-315. [PMID: 26984615 PMCID: PMC4942415 DOI: 10.1007/s10867-016-9408-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 01/04/2016] [Indexed: 12/11/2022] Open
Abstract
The amyloid β (A β) peptide is important in the context of Alzheimer’s disease, since it is one of the major components of the fibrils that constitute amyloid plaques. Agents that can influence fibril formation are important, and of those, membrane mimics are particularly relevant, because the hydrophobic part of A β suggests a possible membrane activity of the peptide. We employed spin-label EPR to investigate the aggregation process of A β1–40 in the presence of the sodium dodecyl sulfate (SDS) detergent as a membrane-mimicking agent. In this work, the effect of SDS on A β is studied using two positions of spin label, the N-terminus and position 26. By comparing the two label positions, the effect of local mobility of the spin label is eliminated, revealing A β aggregation in the SDS concentration regime below the critical micelle concentration (CMC). We demonstrate that, at low SDS concentrations, the N-terminus of A β participates in the solubilization, most likely by being located at the particle–water interface. At higher SDS concentrations, an SDS-solubilized state that is a precursor to the one A β/micelle state above the CMC of SDS prevails. We propose that A β is membrane active and that aggregates include SDS. This study reveals the unique potential of EPR in studying A β aggregation in the presence of detergent.
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Schilder J, Liu WM, Kumar P, Overhand M, Huber M, Ubbink M. Protein docking using an ensemble of spin labels optimized by intra-molecular paramagnetic relaxation enhancement. Phys Chem Chem Phys 2016; 18:5729-42. [DOI: 10.1039/c5cp03781f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The effect of spin label mobility on the accuracy of protein–protein docking calculations was investigated using inter- and intra-molecular PRE data.
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Affiliation(s)
- Jesika Schilder
- Leiden Institute of Chemistry
- Leiden University
- Gorlaeus Laboratories
- 2333 CC Leiden
- The Netherlands
| | - Wei-Min Liu
- Leiden Institute of Chemistry
- Leiden University
- Gorlaeus Laboratories
- 2333 CC Leiden
- The Netherlands
| | - Pravin Kumar
- Department of Physics
- Huygens-Kamerlingh Onnes Laboratory
- Leiden University
- 2333 CA Leiden
- The Netherlands
| | - Mark Overhand
- Leiden Institute of Chemistry
- Leiden University
- Gorlaeus Laboratories
- 2333 CC Leiden
- The Netherlands
| | - Martina Huber
- Department of Physics
- Huygens-Kamerlingh Onnes Laboratory
- Leiden University
- 2333 CA Leiden
- The Netherlands
| | - Marcellus Ubbink
- Leiden Institute of Chemistry
- Leiden University
- Gorlaeus Laboratories
- 2333 CC Leiden
- The Netherlands
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7
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Kumar P, Segers-Nolten IMJ, Schilderink N, Subramaniam V, Huber M. Parkinson's Protein α-Synuclein Binds Efficiently and with a Novel Conformation to Two Natural Membrane Mimics. PLoS One 2015; 10:e0142795. [PMID: 26588454 PMCID: PMC4654490 DOI: 10.1371/journal.pone.0142795] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 10/27/2015] [Indexed: 01/11/2023] Open
Abstract
Binding of human α-Synuclein, a protein associated with Parkinson’s disease, to natural membranes is thought to be crucial in relation to its pathological and physiological function. Here the binding of αS to small unilamellar vesicles mimicking the inner mitochondrial and the neuronal plasma membrane is studied in situ by continuous wave and pulsed electron paramagnetic resonance. Local binding information of αS spin labeled by MTSL at positions 56 and 69 respectively shows that also helix 2 (residues 50–100) binds firmly to both membranes. By double electron-electron resonance (DEER) on the mutant spin labeled at positions 27 and 56 (αS 27/56) a new conformation on the membrane is found with a distance of 3.6 nm/ 3.7 nm between residues 27 and 56. In view of the low negative charge density of these membranes, the strong interaction is surprising, emphasizing that function and pathology of αS could involve synaptic vesicles and mitochondria.
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Affiliation(s)
- Pravin Kumar
- Department of Physics, Huygens-Kammerlingh-Onnes Laboratory, Leiden University, Leiden, The Netherlands
| | - Ine M. J. Segers-Nolten
- Nanobiophysics, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands
| | - Nathalie Schilderink
- Nanobiophysics, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands
| | - Vinod Subramaniam
- Nanobiophysics, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands
- FOM Institute AMOLF, Amsterdam, The Netherlands
| | - Martina Huber
- Department of Physics, Huygens-Kammerlingh-Onnes Laboratory, Leiden University, Leiden, The Netherlands
- * E-mail:
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8
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Abstract
The F1F0-ATP synthase (EC 3.6.1.34) is a remarkable enzyme that functions as a rotary motor. It is found in the inner membranes of Escherichia coli and is responsible for the synthesis of ATP in response to an electrochemical proton gradient. Under some conditions, the enzyme functions reversibly and uses the energy of ATP hydrolysis to generate the gradient. The ATP synthase is composed of eight different polypeptide subunits in a stoichiometry of α3β3γδεab2c10. Traditionally they were divided into two physically separable units: an F1 that catalyzes ATP hydrolysis (α3β3γδε) and a membrane-bound F0 sector that transports protons (ab2c10). In terms of rotary function, the subunits can be divided into rotor subunits (γεc10) and stator subunits (α3β3δab2). The stator subunits include six nucleotide binding sites, three catalytic and three noncatalytic, formed primarily by the β and α subunits, respectively. The stator also includes a peripheral stalk composed of δ and b subunits, and part of the proton channel in subunit a. Among the rotor subunits, the c subunits form a ring in the membrane, and interact with subunit a to form the proton channel. Subunits γ and ε bind to the c-ring subunits, and also communicate with the catalytic sites through interactions with α and β subunits. The eight subunits are expressed from a single operon, and posttranscriptional processing and translational regulation ensure that the polypeptides are made at the proper stoichiometry. Recent studies, including those of other species, have elucidated many structural and rotary properties of this enzyme.
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9
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Sielaff H, Börsch M. Twisting and subunit rotation in single F(O)(F1)-ATP synthase. Philos Trans R Soc Lond B Biol Sci 2012; 368:20120024. [PMID: 23267178 DOI: 10.1098/rstb.2012.0024] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
F(O)F(1)-ATP synthases are ubiquitous proton- or ion-powered membrane enzymes providing ATP for all kinds of cellular processes. The mechanochemistry of catalysis is driven by two rotary nanomotors coupled within the enzyme. Their different step sizes have been observed by single-molecule microscopy including videomicroscopy of fluctuating nanobeads attached to single enzymes and single-molecule Förster resonance energy transfer. Here we review recent developments of approaches to monitor the step size of subunit rotation and the transient elastic energy storage mechanism in single F(O)F(1)-ATP synthases.
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Affiliation(s)
- Hendrik Sielaff
- Single-Molecule Microscopy Group, Jena University Hospital, Nonnenplan 2-4, 07743 Jena, Germany
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10
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Ernst S, Düser MG, Zarrabi N, Dunn SD, Börsch M. Elastic deformations of the rotary double motor of single FoF1-ATP synthases detected in real time by Förster resonance energy transfer. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1722-31. [DOI: 10.1016/j.bbabio.2012.03.034] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 03/25/2012] [Accepted: 03/29/2012] [Indexed: 11/17/2022]
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11
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Sepkhanova I, Drescher M, Meeuwenoord NJ, Limpens RWAL, Koning RI, Filippov DV, Huber M. Monitoring Alzheimer Amyloid Peptide Aggregation by EPR. APPLIED MAGNETIC RESONANCE 2009; 36:209-222. [PMID: 19946595 PMCID: PMC2779421 DOI: 10.1007/s00723-009-0019-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2008] [Revised: 12/28/2008] [Indexed: 05/28/2023]
Abstract
Plaques containing the aggregated beta-Amyloid (Abeta) peptide in the brain are the main indicators of Alzheimer's disease. Fibrils, the building blocks of plaques, can also be produced in vitro and consist of a regular arrangement of the peptide. The initial steps of fibril formation are not well understood and could involve smaller aggregates (oligomers) of Abeta. Such oligomers have even been implicated as the toxic agents. Here, a method to study oligomers on the time scale of aggregation is suggested. We have labeled the 40 residue Abeta peptide variant containing an N-terminal cysteine (cys-Abeta) with the MTSL [1-oxyl-2,2,5,5-tetramethyl-Delta-pyrroline-3-methyl] methanethiosulfonate spin label (SL-Abeta). Fibril formation in solutions of pure SL-Abeta and of SL-Abeta mixed with Abeta was shown by Congo-red binding and electron microscopy. Continuous-wave 9 GHz electron paramagnetic resonance reveals three fractions of different spin-label mobility: one attributed to monomeric Abeta, one to a multimer (8-15 monomers), and the last one to larger aggregates or fibrils. The approach, in principle, allows detection of oligomers on the time scale of aggregation.
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Affiliation(s)
- I. Sepkhanova
- Huygens Laboratory, Department of Molecular Physics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
| | - M. Drescher
- Huygens Laboratory, Department of Molecular Physics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
| | - N. J. Meeuwenoord
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - R. W. A. L. Limpens
- Section Electron Microscopy, Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - R. I. Koning
- Section Electron Microscopy, Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - D. V. Filippov
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - M. Huber
- Huygens Laboratory, Department of Molecular Physics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
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12
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Solution structure, determined by nuclear magnetic resonance, of the b30-82 domain of subunit b of Escherichia coli F1Fo ATP synthase. J Bacteriol 2009; 191:7538-44. [PMID: 19820091 DOI: 10.1128/jb.00540-09] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Subunit b, the peripheral stalk of bacterial F(1)F(o) ATP synthases, is composed of a membrane-spanning and a soluble part. The soluble part is divided into tether, dimerization, and delta-binding domains. The first solution structure of b30-82, including the tether region and part of the dimerization domain, has been solved by nuclear magnetic resonance, revealing an alpha-helix between residues 39 and 72. In the solution structure, b30-82 has a length of 48.07 A. The surface charge distribution of b30-82 shows one side with a hydrophobic surface pattern, formed by alanine residues. Alanine residues 61, 68, 70, and 72 were replaced by single cysteines in the soluble part of subunit b, b22-156. The cysteines at positions 61, 68, and 72 showed disulfide formation. In contrast, no cross-link could be formed for the A70C mutant. The patterns of disulfide bonding, together with the circular dichroism spectroscopy data, are indicative of an adjacent arrangement of residues 61, 68, and 72 in both alpha-helices in b22-156.
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13
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Scarpelli F, Drescher M, Rutters-Meijneke T, Holt A, Rijkers DTS, Killian JA, Huber M. Aggregation of Transmembrane Peptides Studied by Spin-Label EPR. J Phys Chem B 2009; 113:12257-64. [DOI: 10.1021/jp901371h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Francesco Scarpelli
- Department of Molecular Physics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, Chemical Biology & Organic Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands, and Medicinal Chemistry and Chemical Biology, Utrecht Institute for Pharmaceutical Sciences, Department of Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Malte Drescher
- Department of Molecular Physics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, Chemical Biology & Organic Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands, and Medicinal Chemistry and Chemical Biology, Utrecht Institute for Pharmaceutical Sciences, Department of Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Tania Rutters-Meijneke
- Department of Molecular Physics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, Chemical Biology & Organic Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands, and Medicinal Chemistry and Chemical Biology, Utrecht Institute for Pharmaceutical Sciences, Department of Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Andrea Holt
- Department of Molecular Physics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, Chemical Biology & Organic Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands, and Medicinal Chemistry and Chemical Biology, Utrecht Institute for Pharmaceutical Sciences, Department of Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Dirk T. S. Rijkers
- Department of Molecular Physics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, Chemical Biology & Organic Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands, and Medicinal Chemistry and Chemical Biology, Utrecht Institute for Pharmaceutical Sciences, Department of Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - J. Antoinette Killian
- Department of Molecular Physics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, Chemical Biology & Organic Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands, and Medicinal Chemistry and Chemical Biology, Utrecht Institute for Pharmaceutical Sciences, Department of Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Martina Huber
- Department of Molecular Physics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, Chemical Biology & Organic Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands, and Medicinal Chemistry and Chemical Biology, Utrecht Institute for Pharmaceutical Sciences, Department of Pharmaceutical Sciences, Faculty of Science, Utrecht University, Utrecht, The Netherlands
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14
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Wise JG, Vogel PD. Accommodating discontinuities in dimeric left-handed coiled coils in ATP synthase external stalks. Biophys J 2009; 96:2823-31. [PMID: 19348765 DOI: 10.1016/j.bpj.2008.12.3938] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Revised: 11/19/2008] [Accepted: 12/17/2008] [Indexed: 11/16/2022] Open
Abstract
ATP synthases from coupling membranes are complex rotary motors that convert the energy of proton gradients across coupling membranes into the chemical potential of the beta-gamma anhydride bond of ATP. Proton movement within the ring of c subunits localized in the F(0)-sector drives gamma and epsilon rotation within the F(1)alpha(3)beta(3) catalytic core where substrates are bound and products are released. An external stalk composed of homodimeric subunits b(2) in Escherichia coli or heterodimeric bb' in photosynthetic synthases connects F(0) subunit a with F(1) subunits delta and most likely alpha. The external stalk resists rotation, and is of interest both functionally and structurally. Hypotheses that the external stalk contributes to the overall efficiency of the reaction through elastic coupling of rotational substeps, and that stalks form staggered, right-handed coiled coils, are investigated here. We report on different structures that accommodate heptad discontinuities with either local or global underwinding. Analyses of the knob-and-hole packing of the E. coli b(2) and Synechocystis bb' stalks strongly support the possibility that these proteins can adopt conventional left-handed coiled coils.
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Affiliation(s)
- John G Wise
- Department of Biological Sciences, Southern Methodist University, Dallas, Texas 75275, USA.
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15
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Claggett SB, Plancher MO, Dunn SD, Cain BD. The b subunits in the peripheral stalk of F1F0 ATP synthase preferentially adopt an offset relationship. J Biol Chem 2009; 284:16531-16540. [PMID: 19369253 DOI: 10.1074/jbc.m109.002980] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The peripheral stalk of F1F0 ATP synthase is essential for the binding of F1 to FO and for proper transfer of energy between the two sectors of the enzyme. The peripheral stalk of Escherichia coli is composed of a dimer of identical b subunits. In contrast, photosynthetic organisms express two b-like genes that form a heterodimeric peripheral stalk. Previously we generated chimeric peripheral stalks in which a portion of the tether and dimerization domains of the E. coli b subunits were replaced with homologous sequences from the b and b' subunits of Thermosynechococcus elongatus (Claggett, S. B., Grabar, T. B., Dunn, S. D., and Cain, B. D. (2007) J. Bacteriol. 189, 5463-5471). The spatial arrangement of the chimeric b and b' subunits, abbreviated Tb and Tb', has been investigated by Cu2+-mediated disulfide cross-link formation. Disulfide formation was studied both in soluble model polypeptides and between full-length subunits within intact functional F1F0 ATP synthase complexes. In both cases, disulfides were preferentially formed between TbA83C and Tb'A90C, indicating the existence of a staggered relationship between helices of the two chimeric subunits. Even under stringent conditions rapid formation of disulfides between these positions occurred. Importantly, formation of this cross-link had no detectable effect on ATP-driven proton pumping, indicating that the staggered conformation is compatible with normal enzymatic activity. Under less stringent reaction conditions, it was also possible to detect b subunits cross-linked through identical positions, suggesting that an in-register, nonstaggered parallel conformation may also exist.
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Affiliation(s)
- Shane B Claggett
- From the Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida 32605
| | - Mac O'Neil Plancher
- From the Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida 32605
| | - Stanley D Dunn
- Department of Biochemistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Brian D Cain
- From the Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida 32605.
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16
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Zaida TM, Hornung T, Volkov OA, Hoffman AD, Pandey SJ, Wise JG, Vogel PD. Conformational changes in the Escherichia coli ATP synthase b-dimer upon binding to F(1)-ATPase. J Bioenerg Biomembr 2009; 40:551-9. [PMID: 19142720 DOI: 10.1007/s10863-008-9189-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Accepted: 11/24/2008] [Indexed: 11/28/2022]
Abstract
Conformational changes within the subunit b-dimer of the E. coli ATP synthase occur upon binding to the F(1) sector. ESR spectra of spin-labeled b at room temperature indicated a pivotal point in the b-structure at residue 62. Spectra of frozen b +/- F(1) and calculated interspin distances suggested that where contact between b (2) and F(1) occurs (above about residue 80), the structure of the dimer changes minimally. Between b-residues 33 and 64 inter-subunit distances in the F(1)-bound b-dimer were found to be too large to accommodate tightly coiled coil packing and therefore suggest a dissociation and disengagement of the dimer upon F(1)-binding. Mechanistic implications of this "bubble" formation in the tether domain of ATP synthase b ( 2 ) are discussed.
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Affiliation(s)
- Tarek M Zaida
- Department of Biological Sciences, Southern Methodist University, 6501 Airline Rd., Dallas, TX 75275, USA
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17
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Drescher M, Godschalk F, Veldhuis G, van Rooijen BD, Subramaniam V, Huber M. Spin-label EPR on alpha-synuclein reveals differences in the membrane binding affinity of the two antiparallel helices. Chembiochem 2008; 9:2411-6. [PMID: 18821550 DOI: 10.1002/cbic.200800238] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The putative function of the Parkinson's disease-related protein alpha-Synuclein (alphaS) is thought to involve membrane binding. Therefore, the interaction of alphaS with membranes composed of zwitterionic (POPC) and anionic (POPG) lipids was investigated through the mobility of spin labels attached to the protein. Differently labelled variants of alphaS were produced, containing a spin label at positions 9, 18 (both helix 1), 69, 90 (both helix 2), and 140 (C terminus). Protein binding to POPC/POPG vesicles for all but alphaS140 resulted in two mobility components with correlation times of 0.5 and 3 ns, for POPG mole fractions >0.4. Monitoring these components as a function of the POPG mole fraction revealed that at low negative-charge densities helix 1 is more tightly bound than helix 2; this indicates a partially bound form of alphaS. Thus, the interaction of alphaS with membranes of low charge densities might be initiated at helix 1. The local binding information thus obtained gives a more differentiated picture of the affinity of alphaS to membranes. These findings contribute to our understanding of the details and structural consequences of alphaS-membrane interactions.
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Affiliation(s)
- Malte Drescher
- Department of Molecular Physics, Leiden University, 2300 RA Leiden, The Netherlands
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18
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Finiguerra MG, Prudêncio M, Ubbink M, Huber M. Accurate long-range distance measurements in a doubly spin-labeled protein by a four-pulse, double electron-electron resonance method. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2008; 46:1096-1101. [PMID: 18932181 DOI: 10.1002/mrc.2290] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Distance determination in disordered systems by a four-pulse double electron-electron resonance method (DEER or PELDOR) is becoming increasingly popular because long distances (several nanometers) and their distributions can be measured. From the distance distributions eventual heterogeneities and dynamics can be deduced. To make full use of the method, typical distance distributions for structurally well-defined systems are needed. Here, the structurally well-characterized protein azurin is investigated by attaching two (1-oxyl-2,2,5,5-tetramethylpyrroline-3-methyl) methanethiosulfonate spin labels (MTSL) by site-directed mutagenesis. Mutations at the surface sites of the protein Q12, K27, and N42 are combined in the double mutants Q12C/K27C and K27C/N42C. A distance of 4.3 nm is found for Q12C/K27C and 4.6 nm for K27C/N42C. For Q12C/K27C the width of the distribution (0.24 nm) is smaller than for the K27C/N42C mutant (0.36 nm). The shapes of the distributions are close to Gaussian. These distance distributions agree well with those derived from a model to determine the maximally accessible conformational space of the spin-label linker. Additionally, the expected distribution for the shorter distance variant Q12C/N42C was modeled. The width is larger than the calculated one for Q12C/K27C by 21%, revealing the effect of the different orientation and shorter distance. The widths and the shapes of the distributions are suited as a reference for two unperturbed MTSL labels at structurally well-defined sites.
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Affiliation(s)
- Michela G Finiguerra
- Department of Molecular Physics, Leiden University, 2300 RA Leiden, The Netherlands
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19
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Drescher M, Veldhuis G, van Rooijen BD, Milikisyants S, Subramaniam V, Huber M. Antiparallel Arrangement of the Helices of Vesicle-Bound α-Synuclein. J Am Chem Soc 2008; 130:7796-7. [DOI: 10.1021/ja801594s] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Malte Drescher
- Department of Molecular Physics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Biophysical Engineering, MESA+ Institute for Nanotechnology and Institute for Biomedical Technology, University of Twente, Zuidhorst ZH163, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Gertjan Veldhuis
- Department of Molecular Physics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Biophysical Engineering, MESA+ Institute for Nanotechnology and Institute for Biomedical Technology, University of Twente, Zuidhorst ZH163, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Bart D. van Rooijen
- Department of Molecular Physics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Biophysical Engineering, MESA+ Institute for Nanotechnology and Institute for Biomedical Technology, University of Twente, Zuidhorst ZH163, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Sergey Milikisyants
- Department of Molecular Physics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Biophysical Engineering, MESA+ Institute for Nanotechnology and Institute for Biomedical Technology, University of Twente, Zuidhorst ZH163, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Vinod Subramaniam
- Department of Molecular Physics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Biophysical Engineering, MESA+ Institute for Nanotechnology and Institute for Biomedical Technology, University of Twente, Zuidhorst ZH163, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Martina Huber
- Department of Molecular Physics, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Biophysical Engineering, MESA+ Institute for Nanotechnology and Institute for Biomedical Technology, University of Twente, Zuidhorst ZH163, P.O. Box 217, 7500 AE Enschede, The Netherlands
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20
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Subunit b-dimer of the Escherichia coli ATP synthase can form left-handed coiled-coils. Biophys J 2008; 94:5040-52. [PMID: 18326648 DOI: 10.1529/biophysj.107.121012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
One remaining challenge to our understanding of the ATP synthase concerns the dimeric coiled-coil stator subunit b of bacterial synthases. The subunit b-dimer has been implicated in important protein interactions that appear necessary for energy conservation and that may be instrumental in energy conservation during rotary catalysis by the synthase. Understanding the stator structure and its interactions with the rest of the enzyme is crucial to the understanding of the overall catalytic mechanism. Controversy exists on whether subunit b adopts a classic left-handed or a presumed right-handed dimeric coiled-coil and whether or not staggered pairing between nonhomologous residues in the homodimer is required for intersubunit packing. In this study we generated molecular models of the Escherichia coli subunit b-dimer that were based on the well-established heptad-repeat packing exhibited by left-handed, dimeric coiled-coils by employing simulated annealing protocols with structural restraints collected from known structures. In addition, we attempted to create hypothetical right-handed coiled-coil models and left- and right-handed models with staggered packing in the coiled-coil domains. Our analyses suggest that the available structural and biochemical evidence for subunit b can be accommodated by classic left-handed, dimeric coiled-coil quaternary structures.
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21
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Structure of the cytosolic part of the subunit b-dimer of Escherichia coli F0F1-ATP synthase. Biophys J 2008; 94:5053-64. [PMID: 18326647 DOI: 10.1529/biophysj.107.121038] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The structure of the external stalk and its function in the catalytic mechanism of the F(0)F(1)-ATP synthase remains one of the important questions in bioenergetics. The external stalk has been proposed to be either a rigid stator that binds F(1) or an elastic structural element that transmits energy from the small rotational steps of subunits c to the F(1) sector during catalysis. We employed proteomics, sequence-based structure prediction, molecular modeling, and electron spin resonance spectroscopy using site-directed spin labeling to understand the structure and interfacial packing of the Escherichia coli b-subunit homodimer external stalk. Comparisons of bacterial, cyanobacterial, and plant b-subunits demonstrated little sequence similarity. Supersecondary structure predictions, however, show that all compared b-sequences have extensive heptad repeats, suggesting that the proteins all are capable of packing as left-handed coiled-coils. Molecular modeling subsequently indicated that b(2) from the E. coli ATP synthase could pack into stable left-handed coiled-coils. Thirty-eight substitutions to cysteine in soluble b-constructs allowed the introduction of spin labels and the determination of intersubunit distances by ESR. These distances correlated well with molecular modeling results and strongly suggest that the E. coli subunit b-dimer can stably exist as a left-handed coiled-coil.
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22
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Smirnova I, Kasho V, Choe JY, Altenbach C, Hubbell WL, Kaback HR. Sugar binding induces an outward facing conformation of LacY. Proc Natl Acad Sci U S A 2007; 104:16504-9. [PMID: 17925435 PMCID: PMC2034228 DOI: 10.1073/pnas.0708258104] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Indexed: 11/18/2022] Open
Abstract
According to x-ray structure, the lactose permease (LacY) is a monomer organized into N- and C-terminal six-helix bundles that form a deep internal cavity open on the cytoplasmic side with a single sugar-binding site at the apex. The periplasmic side of the molecule is closed. During sugar/H(+) symport, a cavity facing the periplasmic side is thought to open with closure of the inward-facing cytoplasmic cavity so that the sugar-binding site is alternately accessible to either face of the membrane. Double electron-electron resonance (DEER) is used here to measure interhelical distance changes induced by sugar binding to LacY. Nitroxide-labeled paired-Cys replacements were constructed at the ends of transmembrane helices on the cytoplasmic or periplasmic sides of wild-type LacY and in the conformationally restricted mutant Cys-154-->Gly. Distances were then determined in the presence of galactosidic or nongalactosidic sugars. Strikingly, specific binding causes conformational rearrangement on both sides of the molecule. On the cytoplasmic side, each of six nitroxide-labeled pairs exhibits decreased interspin distances ranging from 4 to 21 A. Conversely, on the periplasmic side, each of three spin-labeled pairs shows increased distances ranging from 4 to 14 A. Thus, the inward-facing cytoplasmic cavity closes, and a cleft opens on the tightly packed periplasmic side. In the Cys-154-->Gly mutant, sugar-induced closing is observed on the cytoplasmic face, but little or no change occurs on periplasmic side. The DEER measurements in conjunction with molecular modeling based on the x-ray structure provide strong support for the alternative access model and reveal a structure for the outward-facing conformer of LacY.
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Affiliation(s)
| | | | | | - Christian Altenbach
- Jules Stein Eye Institute, and
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095
| | - Wayne L. Hubbell
- Jules Stein Eye Institute, and
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095
| | - H. Ronald Kaback
- *Department of Physiology
- Department of Microbiology, Immunology, and Molecular Genetics
- Molecular Biology Institute
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23
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Schiemann O, Prisner TF. Long-range distance determinations in biomacromolecules by EPR spectroscopy. Q Rev Biophys 2007; 40:1-53. [PMID: 17565764 DOI: 10.1017/s003358350700460x] [Citation(s) in RCA: 423] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Electron paramagnetic resonance (EPR) spectroscopy provides a variety of tools to study structures and structural changes of large biomolecules or complexes thereof. In order to unravel secondary structure elements, domain arrangements or complex formation, continuous wave and pulsed EPR methods capable of measuring the magnetic dipole coupling between two unpaired electrons can be used to obtain long-range distance constraints on the nanometer scale. Such methods yield reliably and precisely distances of up to 80 A, can be applied to biomolecules in aqueous buffer solutions or membranes, and are not size limited. They can be applied either at cryogenic or physiological temperatures and down to amounts of a few nanomoles. Spin centers may be metal ions, metal clusters, cofactor radicals, amino acid radicals, or spin labels. In this review, we discuss the advantages and limitations of the different EPR spectroscopic methods, briefly describe their theoretical background, and summarize important biological applications. The main focus of this article will be on pulsed EPR methods like pulsed electron-electron double resonance (PELDOR) and their applications to spin-labeled biosystems.
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Affiliation(s)
- Olav Schiemann
- Institute of Physical and Theoretical Chemistry, Center for Biomolecular Magnetic Resonance, J. W. Goethe-University Frankfurt, 60438 Frankfurt am Main, Germany.
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24
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Del Rizzo PA, Bi Y, Dunn SD. ATP synthase b subunit dimerization domain: a right-handed coiled coil with offset helices. J Mol Biol 2006; 364:735-46. [PMID: 17028022 DOI: 10.1016/j.jmb.2006.09.028] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Revised: 09/06/2006] [Accepted: 09/08/2006] [Indexed: 11/29/2022]
Abstract
The dimerization domain of Escherichia coli ATP synthase b subunit forms an atypical parallel two-stranded coiled coil. Sequence analysis reveals an 11-residue abcdefghijk repeat characteristic of right-handed coiled coils, but no other naturally occurring parallel dimeric structure of this class has been identified. The arrangement of the helices was studied by their propensity to form interhelix disulfide linkages and analysis of the stability and shape of disulfide-linked dimers. Disulfides formed preferentially between cysteine residues in an a position of one helix and either of the adjacent h positions of the partner. Such heterodimers were far more stable to thermal denaturation than homodimers and, on the basis of gel-filtration chromatography studies, were similar in shape to both non-covalent dimers and dimers linked through flexible Gly(1-3)Cys C-terminal extensions. The results indicate a right-handed coiled-coil structure with intrinsic asymmetry, the two helices being offset rather than in register. A function for the right-handed coiled coil in rotational catalysis is proposed.
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Affiliation(s)
- Paul A Del Rizzo
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada, N6A 5C1
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25
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Weber J. ATP synthase: subunit-subunit interactions in the stator stalk. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:1162-70. [PMID: 16730323 PMCID: PMC1785291 DOI: 10.1016/j.bbabio.2006.04.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2006] [Revised: 03/20/2006] [Accepted: 04/05/2006] [Indexed: 11/20/2022]
Abstract
In ATP synthase, proton translocation through the Fo subcomplex and ATP synthesis/hydrolysis in the F1 subcomplex are coupled by subunit rotation. The static, non-rotating portions of F1 and Fo are attached to each other via the peripheral "stator stalk", which has to withstand elastic strain during subunit rotation. In Escherichia coli, the stator stalk consists of subunits b2delta; in other organisms, it has three or four different subunits. Recent advances in this area include affinity measurements between individual components of the stator stalk as well as a detailed analysis of the interaction between subunit delta (or its mitochondrial counterpart, the oligomycin-sensitivity conferring protein, OSCP) and F1. The current status of our knowledge of the structure of the stator stalk and of the interactions between its subunits will be discussed in this review.
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Affiliation(s)
- Joachim Weber
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-1061, USA.
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