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Bell D, Lindemann F, Gerland L, Aucharova H, Klein A, Friedrich D, Hiller M, Grohe K, Meier T, van Rossum B, Diehl A, Hughes J, Mueller LJ, Linser R, Miller AF, Oschkinat H. Sedimentation of large, soluble proteins up to 140 kDa for 1H-detected MAS NMR and 13C DNP NMR - practical aspects. JOURNAL OF BIOMOLECULAR NMR 2024:10.1007/s10858-024-00444-9. [PMID: 38904893 DOI: 10.1007/s10858-024-00444-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 05/08/2024] [Indexed: 06/22/2024]
Abstract
Solution NMR is typically applied to biological systems with molecular weights < 40 kDa whereas magic-angle-spinning (MAS) solid-state NMR traditionally targets very large, oligomeric proteins and complexes exceeding 500 kDa in mass, including fibrils and crystalline protein preparations. Here, we propose that the gap between these size regimes can be filled by the approach presented that enables investigation of large, soluble and fully protonated proteins in the range of 40-140 kDa. As a key step, ultracentrifugation produces a highly concentrated, gel-like state, resembling a dense phase in spontaneous liquid-liquid phase separation (LLPS). By means of three examples, a Sulfolobus acidocaldarius bifurcating electron transfer flavoprotein (SaETF), tryptophan synthases from Salmonella typhimurium (StTS) and their dimeric β-subunits from Pyrococcus furiosus (PfTrpB), we show that such samples yield well-resolved proton-detected 2D and 3D NMR spectra at 100 kHz MAS without heterogeneous broadening, similar to diluted liquids. Herein, we provide practical guidance on centrifugation conditions and tools, sample behavior, and line widths expected. We demonstrate that the observed chemical shifts correspond to those obtained from µM/low mM solutions or crystalline samples, indicating structural integrity. Nitrogen line widths as low as 20-30 Hz are observed. The presented approach is advantageous for proteins or nucleic acids that cannot be deuterated due to the expression system used, or where relevant protons cannot be re-incorporated after expression in deuterated medium, and it circumvents crystallization. Importantly, it allows the use of low-glycerol buffers in dynamic nuclear polarization (DNP) NMR of proteins as demonstrated with the cyanobacterial phytochrome Cph1.
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Affiliation(s)
- Dallas Bell
- Faculty II-Mathematics and Natural Sciences, Technische Universität Berlin, Straße des 17. Juni 135, 10623, Berlin, Germany
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany
| | - Florian Lindemann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany
| | - Lisa Gerland
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany
| | - Hanna Aucharova
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 4a, 44227, Dortmund, Germany
| | - Alexander Klein
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 4a, 44227, Dortmund, Germany
| | - Daniel Friedrich
- Department of Chemistry and Biochemistry, University of Cologne, Greinstr. 4, 50939, Cologne, Germany
| | - Matthias Hiller
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany
| | - Kristof Grohe
- Bruker BioSpin GmbH & Co. KG, Rudolf-Plank-Str. 23, 76275, Ettlingen, Germany
| | - Tobias Meier
- Bruker BioSpin GmbH & Co. KG, Rudolf-Plank-Str. 23, 76275, Ettlingen, Germany
| | - Barth van Rossum
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany
| | - Anne Diehl
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany
| | - Jon Hughes
- Institute for Plant Physiology, Justus Liebig University, Senckenbergstr. 3, 35360, Gießen, Germany
- Department of Physics, Free University of Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Leonard J Mueller
- Department of Chemistry, University of California - Riverside, Riverside, CA, 92521, USA
| | - Rasmus Linser
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 4a, 44227, Dortmund, Germany
| | - Anne-Frances Miller
- Faculty II-Mathematics and Natural Sciences, Technische Universität Berlin, Straße des 17. Juni 135, 10623, Berlin, Germany.
- Department of Chemistry, University of Kentucky, Lexington, KY, 40506, USA.
| | - Hartmut Oschkinat
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany.
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Bell D, Lindemann F, Gerland L, Aucharova H, Klein A, Friedrich D, Hiller M, Grohe K, van Rossum B, Diehl A, Hughes J, Mueller LJ, Linser R, Miller AF, Oschkinat H. Sedimentation of large, soluble proteins up to 140 kDa for 1H-detected MAS NMR and 13C DNP NMR - practical aspects. RESEARCH SQUARE 2024:rs.3.rs-3972885. [PMID: 38464080 PMCID: PMC10925473 DOI: 10.21203/rs.3.rs-3972885/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Solution NMR is typically applied to biological systems with molecular weights < 40 kDa whereas magic-angle-spinning (MAS) solid-state NMR traditionally targets very large, oligomeric proteins and complexes exceeding 500 kDa in mass, including fibrils and crystalline protein preparations. Here, we propose that the gap between these size regimes can be filled by the approach presented that enables investigation of large, soluble and fully protonated proteins in the range of 40-140 kDa. As a key step, ultracentrifugation produces a highly concentrated, gel-like state, resembling a dense phase in spontaneous liquid-liquid phase separation (LLPS). By means of three examples, a Sulfolobus acidocaldarius bifurcating electron transfer flavoprotein (SulfETF), tryptophan synthases from Salmonella typhimurium (StTS) and the dimeric β-subunits from Pyrococcus furiosus (PfTrpB), we show that such samples yield well-resolved proton-detected 2D and 3D NMR spectra at 100 kHz MAS without heterogeneous broadening, similar to diluted liquids. Herein, we provide practical guidance on centrifugation conditions and tools, sample behavior, and line widths expected. We demonstrate that the observed chemical shifts correspond to those obtained from μM/low mM solutions or crystalline samples, indicating structural integrity. Nitrogen line widths as low as 20-30 Hz are observed. The presented approach is advantageous for proteins or nucleic acids that cannot be deuterated due to the expression system used, or where relevant protons cannot be re-incorporated after expression in deuterated medium, and it circumvents crystallization. Importantly, it allows the use of low-glycerol buffers in dynamic nuclear polarization (DNP) NMR of proteins as demonstrated with the cyanobacterial phytochrome Cph1.
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Affiliation(s)
- Dallas Bell
- Faculty II-Mathematics and Natural Sciences, Technische Universität Berlin
| | | | - Lisa Gerland
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie
| | - Hanna Aucharova
- Department of Chemistry and Chemical Biology, TU Dortmund University
| | - Alexander Klein
- Department of Chemistry and Chemical Biology, TU Dortmund University
| | | | | | | | | | - Anne Diehl
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie
| | - Jon Hughes
- Justus Liebig University, Institute for Plant Physiology
| | | | - Rasmus Linser
- Department of Chemistry and Chemical Biology, TU Dortmund University
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Ge X, Schut GJ, Tran J, Poole II FL, Niks D, Menjivar K, Hille R, Adams MWW. Characterization of the Membrane-Associated Electron-Bifurcating Flavoenzyme EtfABCX from the Hyperthermophilic Bacterium Thermotoga maritima. Biochemistry 2023; 62:3554-3567. [PMID: 38061393 PMCID: PMC10734219 DOI: 10.1021/acs.biochem.3c00473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/20/2023] [Accepted: 11/20/2023] [Indexed: 12/20/2023]
Abstract
Electron bifurcation is an energy-conservation mechanism in which a single enzyme couples an exergonic reaction with an endergonic one. Heterotetrameric EtfABCX drives the reduction of low-potential ferredoxin (E°' ∼ -450 mV) by oxidation of the midpotential NADH (E°' = -320 mV) by simultaneously coupling the reaction to reduction of the high-potential menaquinone (E°' = -74 mV). Electron bifurcation occurs at the NADH-oxidizing bifurcating-flavin adenine dinucleotide (BF-FAD) in EtfA, which has extremely crossed half-potentials and passes the first, high-potential electron to an electron-transferring FAD and via two iron-sulfur clusters eventually to menaquinone. The low-potential electron on the BF-FAD semiquinone simultaneously reduces ferredoxin. We have expressed the genes encodingThermotoga maritimaEtfABCX in E. coli and purified the EtfABCX holoenzyme and the EtfAB subcomplex. The bifurcation activity of EtfABCX was demonstrated by using electron paramagnetic resonance (EPR) to follow accumulation of reduced ferredoxin. To elucidate structural factors that impart the bifurcating ability, EPR and NADH titrations monitored by visible spectroscopy and dye-linked enzyme assays have been employed to characterize four conserved residues, R38, P239, and V242 in EtfA and R140 in EtfB, in the immediate vicinity of the BF-FAD. The R38, P239, and V242 variants showed diminished but still significant bifurcation activity. Despite still being partially reduced by NADH, the R140 variant had no bifurcation activity, and electron transfer to its two [4Fe-4S] clusters was prevented. The role of R140 is discussed in terms of the bifurcation mechanism in EtfABCX and in the other three families of bifurcating enzymes.
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Affiliation(s)
- Xiaoxuan Ge
- Department
of Biochemistry and Molecular Biology, University
of Georgia, Athens, Georgia 30602, United States
| | - Gerrit J. Schut
- Department
of Biochemistry and Molecular Biology, University
of Georgia, Athens, Georgia 30602, United States
| | - Jessica Tran
- Department
of Biochemistry, University of California,
Riverside, Riverside, California 92507, United States
| | - Farris L. Poole II
- Department
of Biochemistry and Molecular Biology, University
of Georgia, Athens, Georgia 30602, United States
| | - Dimitri Niks
- Department
of Biochemistry, University of California,
Riverside, Riverside, California 92507, United States
| | - Kevin Menjivar
- Department
of Biochemistry, University of California,
Riverside, Riverside, California 92507, United States
| | - Russ Hille
- Department
of Biochemistry, University of California,
Riverside, Riverside, California 92507, United States
| | - Michael W. W. Adams
- Department
of Biochemistry and Molecular Biology, University
of Georgia, Athens, Georgia 30602, United States
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