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Minshull T, Byrd EJ, Olejnik M, Calabrese AN. Hydrogen-Deuterium Exchange Mass Spectrometry Reveals Mechanistic Insights into RNA Oligonucleotide-Mediated Inhibition of TDP-43 Aggregation. J Am Chem Soc 2024; 146:33626-33639. [PMID: 39610319 PMCID: PMC11638948 DOI: 10.1021/jacs.4c11229] [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: 08/15/2024] [Revised: 11/19/2024] [Accepted: 11/19/2024] [Indexed: 11/30/2024]
Abstract
Deposits of aggregated TAR DNA-binding protein 43 (TDP-43) in the brain are associated with several neurodegenerative diseases. It is well established that binding of RNA/DNA to TDP-43 can prevent TDP-43 aggregation, but an understanding of the structure(s) and conformational dynamics of TDP-43, and TDP-43-RNA complexes, is lacking, including knowledge of how the solution environment modulates these properties. Here, we address this challenge using hydrogen-deuterium exchange-mass spectrometry. In the presence of RNA olignoucleotides, we observe protection from exchange in the RNA recognition motif (RRM) domains of TDP-43 and the linker region between the RRM domains, consistent with nucleic acid binding modulating interdomain interactions. Intriguingly, at elevated salt concentrations, the extent of protection from exchange is reduced in the RRM domains when bound to an RNA sequence derived from the 3' UTR of the TDP-43 mRNA (CLIP34NT) compared to when bound to a (UG)6 repeat sequence. Under these conditions, CLIP34NT is no longer able to prevent TDP-43 aggregation. This suggests that a salt-induced structural rearrangement occurs when bound to this RNA, which may play a role in facilitating aggregation. Additionally, upon RNA binding, we identify differences in exchange within the short α-helical region located in the C-terminal domain (CTD) of TDP-43. These allosterically altered regions may influence the ability of TDP-43 to aggregate and fine-tune its RNA binding repertoire. Combined, these data provide additional insights into the intricate interplay between TDP-43 aggregation and RNA binding, an understanding of which is crucial for unraveling the molecular mechanisms underlying TDP-43-associated neurodegeneration.
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Affiliation(s)
- Thomas
C. Minshull
- Astbury Centre for Structural
Molecular Biology, School of Molecular and Cellular Biology, Faculty
of Biological Sciences, University of Leeds, Leeds LS2 9JT, U.K.
| | - Emily J. Byrd
- Astbury Centre for Structural
Molecular Biology, School of Molecular and Cellular Biology, Faculty
of Biological Sciences, University of Leeds, Leeds LS2 9JT, U.K.
| | - Monika Olejnik
- Astbury Centre for Structural
Molecular Biology, School of Molecular and Cellular Biology, Faculty
of Biological Sciences, University of Leeds, Leeds LS2 9JT, U.K.
| | - Antonio N. Calabrese
- Astbury Centre for Structural
Molecular Biology, School of Molecular and Cellular Biology, Faculty
of Biological Sciences, University of Leeds, Leeds LS2 9JT, U.K.
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Thomas S, Schulz AM, Leong JM, Zeczycki TN, Garcia BL. The molecular determinants of classical pathway complement inhibition by OspEF-related proteins of Borrelia burgdorferi. J Biol Chem 2024; 300:107236. [PMID: 38552741 PMCID: PMC11066524 DOI: 10.1016/j.jbc.2024.107236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 03/18/2024] [Accepted: 03/22/2024] [Indexed: 04/04/2024] Open
Abstract
The complement system serves as the first line of defense against invading pathogens by promoting opsonophagocytosis and bacteriolysis. Antibody-dependent activation of complement occurs through the classical pathway and relies on the activity of initiating complement proteases of the C1 complex, C1r and C1s. The causative agent of Lyme disease, Borrelia burgdorferi, expresses two paralogous outer surface lipoproteins of the OspEF-related protein family, ElpB and ElpQ, that act as specific inhibitors of classical pathway activation. We have previously shown that ElpB and ElpQ bind directly to C1r and C1s with high affinity and specifically inhibit C2 and C4 cleavage by C1s. To further understand how these novel protease inhibitors function, we carried out a series of hydrogen-deuterium exchange mass spectrometry (HDX-MS) experiments using ElpQ and full-length activated C1s as a model of Elp-protease interaction. Comparison of HDX-MS profiles between unbound ElpQ and the ElpQ/C1s complex revealed a putative C1s-binding site on ElpQ. HDX-MS-guided, site-directed ElpQ mutants were generated and tested for direct binding to C1r and C1s using surface plasmon resonance. Several residues within the C-terminal region of ElpQ were identified as important for protease binding, including a single conserved tyrosine residue that was required for ElpQ- and ElpB-mediated complement inhibition. Collectively, our study identifies key molecular determinants for classical pathway protease recognition by Elp proteins. This investigation improves our understanding of the unique complement inhibitory mechanism employed by Elp proteins which serve as part of a sophisticated complement evasion system present in Lyme disease spirochetes.
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Affiliation(s)
- Sheila Thomas
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Anna M Schulz
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - John M Leong
- Department of Molecular Biology and Microbiology, Tufts School of Medicine, Tufts University, Boston, Massachusetts, USA
| | - Tonya N Zeczycki
- Department of Biochemistry & Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Brandon L Garcia
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA.
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Attanayake K, Mahmud S, Banerjee C, Sharif D, Rahman M, Majuta S, DeBastiani A, Sultana MN, Foroushani SH, Li C, Li P, Valentine SJ. Examining DNA Structures with In-droplet Hydrogen/Deuterium Exchange Mass Spectrometry. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 2024; 499:117231. [PMID: 38854816 PMCID: PMC11156224 DOI: 10.1016/j.ijms.2024.117231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Capillary vibrating sharp-edge spray ionization (cVSSI) combined with hydrogen/deuterium exchange-mass spectrometry (HDX-MS) has been utilized to characterize different solution-phase DNA conformers including DNA G-quadruplex topologies as well as triplex DNA and duplex DNA. In general, G-quadruplex DNA shows a wide range of protection of hydrogens extending from ~12% to ~21% deuterium incorporation. Additionally, the DNA sequences selected to represent parallel, antiparallel, and hybrid G-quadruplex topologies exhibit slight differences in deuterium uptake levels which appear to loosely relate to overall conformer stability. Notably, the exchange level for one of the hybrid sequence sub topologies of G-quadruplex DNA (24 TTG) is significantly different (compared with the others studied here) despite the DNA sequences being highly comparable. For the quadruplex-forming sequences, correlation analysis suggests protection of base hydrogens involved in tetrad hydrogen bonding. For duplex DNA ~19% deuterium incorporation is observed while only ~16% is observed for triplex DNA. This increased protection of hydrogens may be due to the added backbone scaffolding and Hoogsteen base pairing of the latter species. These experiments lay the groundwork for future studies aimed at determining the structural source of this protection as well as the applicability of the approach for ascertaining different oligonucleotide folds, co-existing conformations, and/or overall conformer flexibility.
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Affiliation(s)
- Kushani Attanayake
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, USA
| | - Sultan Mahmud
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, USA
| | - Chandrima Banerjee
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, USA
| | - Daud Sharif
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, USA
| | - Mohammad Rahman
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, USA
| | - Sandra Majuta
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, USA
| | - Anthony DeBastiani
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, USA
| | - Mst Nigar Sultana
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, USA
| | | | - Chong Li
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, USA
| | - Peng Li
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, USA
| | - Stephen J Valentine
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, USA
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Cajka T, Hricko J, Rakusanova S, Brejchova K, Novakova M, Rudl Kulhava L, Hola V, Paucova M, Fiehn O, Kuda O. Hydrophilic Interaction Liquid Chromatography-Hydrogen/Deuterium Exchange-Mass Spectrometry (HILIC-HDX-MS) for Untargeted Metabolomics. Int J Mol Sci 2024; 25:2899. [PMID: 38474147 DOI: 10.3390/ijms25052899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 02/17/2024] [Accepted: 02/26/2024] [Indexed: 03/14/2024] Open
Abstract
Liquid chromatography with mass spectrometry (LC-MS)-based metabolomics detects thousands of molecular features (retention time-m/z pairs) in biological samples per analysis, yet the metabolite annotation rate remains low, with 90% of signals classified as unknowns. To enhance the metabolite annotation rates, researchers employ tandem mass spectral libraries and challenging in silico fragmentation software. Hydrogen/deuterium exchange mass spectrometry (HDX-MS) may offer an additional layer of structural information in untargeted metabolomics, especially for identifying specific unidentified metabolites that are revealed to be statistically significant. Here, we investigate the potential of hydrophilic interaction liquid chromatography (HILIC)-HDX-MS in untargeted metabolomics. Specifically, we evaluate the effectiveness of two approaches using hypothetical targets: the post-column addition of deuterium oxide (D2O) and the on-column HILIC-HDX-MS method. To illustrate the practical application of HILIC-HDX-MS, we apply this methodology using the in silico fragmentation software MS-FINDER to an unknown compound detected in various biological samples, including plasma, serum, tissues, and feces during HILIC-MS profiling, subsequently identified as N1-acetylspermidine.
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Affiliation(s)
- Tomas Cajka
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200 Prague, Czech Republic
| | - Jiri Hricko
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200 Prague, Czech Republic
| | - Stanislava Rakusanova
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200 Prague, Czech Republic
| | - Kristyna Brejchova
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200 Prague, Czech Republic
| | - Michaela Novakova
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200 Prague, Czech Republic
| | - Lucie Rudl Kulhava
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200 Prague, Czech Republic
| | - Veronika Hola
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200 Prague, Czech Republic
| | - Michaela Paucova
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200 Prague, Czech Republic
| | - Oliver Fiehn
- West Coast Metabolomics Center, University of California, Davis, 451 Health Sciences Drive, Davis, CA 95616, USA
| | - Ondrej Kuda
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200 Prague, Czech Republic
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