1
|
Moeller J, Bozhanova NG, Voehler M, Meiler J, Schoeder CT. Backbone chemical shift and secondary structure assignments for mouse siderocalin. Biomol NMR Assign 2024; 18:79-84. [PMID: 38564159 PMCID: PMC11081974 DOI: 10.1007/s12104-024-10171-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 03/16/2024] [Indexed: 04/04/2024]
Abstract
The lipocalin protein family is a structurally conserved group of proteins with a variety of biological functions defined by their ability to bind small molecule ligands and interact with partner proteins. One member of this family is siderocalin, a protein found in mammals. Its role is discussed in inflammatory processes, iron trafficking, protection against bacterial infections and oxidative stress, cell migration, induction of apoptosis, and cancer. Though it seems to be involved in numerous essential pathways, the exact mechanisms are often not fully understood. The NMR backbone assignments for the human siderocalin and its rat ortholog have been published before. In this work we describe the backbone NMR assignments of siderocalin for another important model organism, the mouse - data that might become important for structure-based drug discovery. Secondary structure elements were predicted based on the assigned backbone chemical shifts using TALOS-N and CSI 3.0, revealing a high content of beta strands and one prominent alpha helical region. Our findings correlate well with the known crystal structure and the overall conserved fold of the lipocalin family.
Collapse
Affiliation(s)
- Johanna Moeller
- Institute for Drug Discovery, Leipzig University Medical School, 04103, Leipzig, Germany
- Center for Scalable Data Analytics and Artificial Intelligence (ScaDS.AI) Dresden/Leipzig, Leipzig University, Leipzig, Germany
| | - Nina G Bozhanova
- Center for Structural Biology, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Markus Voehler
- Center for Structural Biology, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Jens Meiler
- Institute for Drug Discovery, Leipzig University Medical School, 04103, Leipzig, Germany
- Center for Structural Biology, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Clara T Schoeder
- Institute for Drug Discovery, Leipzig University Medical School, 04103, Leipzig, Germany.
- Center for Scalable Data Analytics and Artificial Intelligence (ScaDS.AI) Dresden/Leipzig, Leipzig University, Leipzig, Germany.
| |
Collapse
|
2
|
Sharma P, Maklashina E, Voehler M, Balintova S, Dvorakova S, Kraus M, Hadrava Vanova K, Nahacka Z, Zobalova R, Boukalova S, Cunatova K, Mracek T, Ghayee HK, Pacak K, Rohlena J, Neuzil J, Cecchini G, Iverson TM. Disordered-to-ordered transitions in assembly factors allow the complex II catalytic subunit to switch binding partners. Nat Commun 2024; 15:473. [PMID: 38212624 PMCID: PMC10784507 DOI: 10.1038/s41467-023-44563-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 12/19/2023] [Indexed: 01/13/2024] Open
Abstract
Complex II (CII) activity controls phenomena that require crosstalk between metabolism and signaling, including neurodegeneration, cancer metabolism, immune activation, and ischemia-reperfusion injury. CII activity can be regulated at the level of assembly, a process that leverages metastable assembly intermediates. The nature of these intermediates and how CII subunits transfer between metastable complexes remains unclear. In this work, we identify metastable species containing the SDHA subunit and its assembly factors, and we assign a preferred temporal sequence of appearance of these species during CII assembly. Structures of two species show that the assembly factors undergo disordered-to-ordered transitions without the appearance of significant secondary structure. The findings identify that intrinsically disordered regions are critical in regulating CII assembly, an observation that has implications for the control of assembly in other biomolecular complexes.
Collapse
Affiliation(s)
- Pankaj Sharma
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
| | - Elena Maklashina
- Molecular Biology Division, San Francisco VA Health Care System, San Francisco, CA, 94121, USA
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA, 94158, USA
| | - Markus Voehler
- Department of Chemistry Vanderbilt University, Nashville, TN, 37232, USA
- Center for Structural Biology Vanderbilt University, Nashville, TN, 37232, USA
| | - Sona Balintova
- Institute of Biotechnology, Czech Academy of Sciences, 252 50, Prague-West, Czech Republic
- Faculty of Science, Charles University, 128 00, Prague 2, Czech Republic
| | - Sarka Dvorakova
- Institute of Biotechnology, Czech Academy of Sciences, 252 50, Prague-West, Czech Republic
| | - Michal Kraus
- Institute of Biotechnology, Czech Academy of Sciences, 252 50, Prague-West, Czech Republic
| | - Katerina Hadrava Vanova
- Institute of Biotechnology, Czech Academy of Sciences, 252 50, Prague-West, Czech Republic
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20814, USA
| | - Zuzana Nahacka
- Institute of Biotechnology, Czech Academy of Sciences, 252 50, Prague-West, Czech Republic
| | - Renata Zobalova
- Institute of Biotechnology, Czech Academy of Sciences, 252 50, Prague-West, Czech Republic
| | - Stepana Boukalova
- Institute of Biotechnology, Czech Academy of Sciences, 252 50, Prague-West, Czech Republic
| | - Kristyna Cunatova
- Institute of Physiology, Czech Academy of Sciences, Prague 4, 142 20, Prague, Czech Republic
| | - Tomas Mracek
- Institute of Physiology, Czech Academy of Sciences, Prague 4, 142 20, Prague, Czech Republic
| | - Hans K Ghayee
- Department of Medicine, Division of Endocrinology & Metabolism, University of Florida College of Medicine and Malcom Randall, VA Medical Center, Gainesville, FL, 32608, USA
| | - Karel Pacak
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20814, USA
| | - Jakub Rohlena
- Institute of Biotechnology, Czech Academy of Sciences, 252 50, Prague-West, Czech Republic
| | - Jiri Neuzil
- Institute of Biotechnology, Czech Academy of Sciences, 252 50, Prague-West, Czech Republic.
- Faculty of Science, Charles University, 128 00, Prague 2, Czech Republic.
- School of Pharmacy and Medical Science, Griffith University, Southport, QLD, 4222, Australia.
- 1st Faculty of Medicine, Charles University, 128 00, Prague 2, Czech Republic.
| | - Gary Cecchini
- Molecular Biology Division, San Francisco VA Health Care System, San Francisco, CA, 94121, USA.
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA, 94158, USA.
| | - T M Iverson
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA.
- Center for Structural Biology Vanderbilt University, Nashville, TN, 37232, USA.
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA.
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, 37232, USA.
| |
Collapse
|
3
|
Woods H, Schiano DL, Aguirre JI, Ledwitch KV, McDonald EF, Voehler M, Meiler J, Schoeder CT. Computational modeling and prediction of deletion mutants. Structure 2023:S0969-2126(23)00128-4. [PMID: 37119820 DOI: 10.1016/j.str.2023.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 03/02/2023] [Accepted: 04/05/2023] [Indexed: 05/01/2023]
Abstract
In-frame deletion mutations can result in disease. The impact of these mutations on protein structure and subsequent functional changes remain understudied, partially due to the lack of comprehensive datasets including a structural readout. In addition, the recent breakthrough in structure prediction through deep learning demands an update of computational deletion mutation prediction. In this study, we deleted individually every residue of a small α-helical sterile alpha motif domain and investigated the structural and thermodynamic changes using 2D NMR spectroscopy and differential scanning fluorimetry. Then, we tested computational protocols to model and classify observed deletion mutants. We show a method using AlphaFold2 followed by RosettaRelax performs the best overall. In addition, a metric containing pLDDT values and Rosetta ΔΔG is most reliable in classifying tolerated deletion mutations. We further test this method on other datasets and show they hold for proteins known to harbor disease-causing deletion mutations.
Collapse
Affiliation(s)
- Hope Woods
- Center of Structural Biology, Vanderbilt University, Nashville, TN 37235, USA; Chemical and Physical Biology Program, Vanderbilt University, Nashville, TN 37235, USA
| | - Dominic L Schiano
- Center of Structural Biology, Vanderbilt University, Nashville, TN 37235, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Jonathan I Aguirre
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Kaitlyn V Ledwitch
- Center of Structural Biology, Vanderbilt University, Nashville, TN 37235, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Eli F McDonald
- Center of Structural Biology, Vanderbilt University, Nashville, TN 37235, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Markus Voehler
- Center of Structural Biology, Vanderbilt University, Nashville, TN 37235, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Jens Meiler
- Center of Structural Biology, Vanderbilt University, Nashville, TN 37235, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA; Institute for Drug Discovery, Leipzig University Medical School, 04103 Leipzig, Germany.
| | - Clara T Schoeder
- Center of Structural Biology, Vanderbilt University, Nashville, TN 37235, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA; Institute for Drug Discovery, Leipzig University Medical School, 04103 Leipzig, Germany.
| |
Collapse
|
4
|
Maddur AA, Voehler M, Panizzi P, Meiler J, Bock PE, Verhamme IM. Mapping of the fibrinogen-binding site on the staphylocoagulase C-terminal repeat region. J Biol Chem 2021; 298:101493. [PMID: 34915025 PMCID: PMC8761706 DOI: 10.1016/j.jbc.2021.101493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 12/08/2021] [Indexed: 01/12/2023] Open
Abstract
Fibrin (Fbn) deposits are a hallmark of staphylocoagulase (SC)-positive endocarditis. Binding of the N terminus of Staphylococcus aureus SC to host prothrombin triggers formation of an active SC·prothrombin∗ complex that cleaves host fibrinogen to Fbn. In addition, the C-terminal domain of the prototypical SC contains one pseudorepeat (PR) and seven repeats (R1 → R7) that bind fibrinogen/Fbn fragment D (frag D) by a mechanism that is unclear. Here, we define affinities and stoichiometries of frag D binding to C-terminal SC constructs, using fluorescence equilibrium binding, NMR titration, alanine scanning, and native PAGE. We found that constructs containing the PR and single repeats bound frag D with KD ∼50 to 130 nM and a 1:1 stoichiometry, indicating a conserved binding site bridging the PR and each repeat. NMR titration of PR-R7 with frag D revealed that residues 22 to 49, bridging PR and R7, constituted the minimal peptide (MP) for binding, corroborated by alanine scanning, and binding of labeled MP to frag D. MP alignment with the PR-R and inter-repeat junctions identified critical conserved residues. Full-length PR-(R1 → R7) bound frag D with KD ∼20 nM and a stoichiometry of 1:5, whereas constructs containing the PR and various three repeats competed with PR-(R1 → R7) for frag D binding, with a 1:3 stoichiometry. These findings are consistent with binding at PR-R and R-R junctions with modest inter-repeat sequence variability. CD of PR-R7 and PR-(R1 → R7) suggested a disordered flexible structure, allowing binding of multiple fibrin(ogen) molecules. Taken together, these results provide insights into pathogen localization on host fibrin networks.
Collapse
Affiliation(s)
- Ashoka A. Maddur
- FUJIFILM Diosynth Biotechnologies, College Station, Texas, USA,For correspondence: Ingrid M. Verhamme; Ashoka A. Maddur
| | - Markus Voehler
- Vanderbilt Center for Structural Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Peter Panizzi
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, Alabama, USA
| | - Jens Meiler
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, USA,Institute for Drug Discovery, Leipzig University Medical School, Leipzig, Germany
| | - Paul E. Bock
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Ingrid M. Verhamme
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA,For correspondence: Ingrid M. Verhamme; Ashoka A. Maddur
| |
Collapse
|
5
|
Tomar R, Minko I, Kellum A, Voehler M, McCullough A, Lloyd R, Stone M. Sequence‐Based Structural Stability Modulate Biological Processing of AFB
1
‐Fapy‐dG Adduct by NEIL1 DNA glycosylase. FASEB J 2021. [DOI: 10.1096/fasebj.2021.35.s1.05386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Irina Minko
- Oregon Institute of Occupational Health SciencesOregon Health & Science UniversityPortlandOR
| | | | | | - Amanda McCullough
- Oregon Institute of Occupational Health SciencesOregon Health & Science UniversityPortlandOR
| | - R. Lloyd
- Oregon Institute of Occupational Health SciencesOregon Health & Science UniversityPortlandOR
| | | |
Collapse
|
6
|
Voehler M, Ashoka MA, Meiler J, Bock PE. Carbon and amide detect backbone assignment methods of a novel repeat protein from the staphylocoagulase in S. aureus. Biomol NMR Assign 2017; 11:243-249. [PMID: 28819722 PMCID: PMC6057470 DOI: 10.1007/s12104-017-9757-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 08/05/2017] [Indexed: 06/07/2023]
Abstract
The C-terminal repeat domain of staphylocoagulase that is secreted by the S. aureus is believed to play an important role interacting with fibrinogen and promotes blood clotting. To study this interaction by NMR, full assignment of each amide residue in the HSQC spectrum was required. Despite of the short sequence of the repeat construct, the HSQC spectrum contained a substantial amount of overlapped and exchange broadened resonances, indicating little secondary or tertiary structure. This caused severe problems while using the conventional, amide based NMR method for the backbone assignment. With the growing interest in small apparently disordered proteins, these issues are being faced more frequently. An alternative strategy to improve the backbone assignment capability involved carbon direct detection methods. Circumventing the amide proton detection offers a larger signal dispersion and more uniform signal intensity. For peptides with higher concentrations and in combination with the cold carbon channels of new cryoprobes, higher fields, and sufficiently long relaxation times, the disadvantage of the lower sensitivity of the 13C nucleus can be overcome. Another advantage of this method is the assignment of the proline backbone residues. Complete assignment with the carbon-detected strategy was achieved with a set of only two 3D, one 2D, and a HNCO measurement, which was necessary to translate the information to the HSQC spectrum.
Collapse
Affiliation(s)
- Markus Voehler
- Department of Chemistry, Center for Structural Biology, Vanderbilt University, Nashville, TN, 37232-8725, USA.
| | - Maddur Appajaiah Ashoka
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Jens Meiler
- Department of Chemistry, Center for Structural Biology, Vanderbilt University, Nashville, TN, 37232-8725, USA
| | - Paul E Bock
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
| |
Collapse
|
7
|
Ketkar A, Voehler M, Mukiza T, Eoff RL. Residues in the RecQ C-terminal Domain of the Human Werner Syndrome Helicase Are Involved in Unwinding G-quadruplex DNA. J Biol Chem 2017; 292:3154-3163. [PMID: 28069813 DOI: 10.1074/jbc.m116.767699] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 01/04/2017] [Indexed: 12/11/2022] Open
Abstract
The structural and biophysical properties typically associated with G-quadruplex (G4) structures render them a significant block for DNA replication, which must be overcome for cell division to occur. The Werner syndrome protein (WRN) is a RecQ family helicase that has been implicated in the efficient processing of G4 DNA structures. The aim of this study was to identify the residues of WRN involved in the binding and ATPase-driven unwinding of G4 DNA. Using a c-Myc G4 DNA model sequence and recombinant WRN, we have determined that the RecQ-C-terminal (RQC) domain of WRN imparts a 2-fold preference for binding to G4 DNA relative to non-G4 DNA substrates. NMR studies identified residues involved specifically in interactions with G4 DNA. Three of the amino acids in the WRN RQC domain that exhibited the largest G4-specific changes in NMR signal were then mutated alone or in combination. Mutating individual residues implicated in G4 binding had a modest effect on WRN binding to DNA, decreasing the preference for G4 substrates by ∼25%. Mutating two G4-interacting residues (T1024G and T1086G) abrogated preferential binding of WRN to G4 DNA. Very modest decreases in G4 DNA-stimulated ATPase activity were observed for the mutant enzymes. Most strikingly, G4 unwinding by WRN was inhibited ∼50% for all three point mutants and >90% for the WRN double mutant (T1024G/T1086G) relative to normal B-form dsDNA substrates. Our work has helped to identify residues in the WRN RQC domain that are involved specifically in the interaction with G4 DNA.
Collapse
Affiliation(s)
- Amit Ketkar
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199
| | - Markus Voehler
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
| | - Tresor Mukiza
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199
| | - Robert L Eoff
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199.
| |
Collapse
|
8
|
Frazier MN, Davies AK, Voehler M, Kendall AK, Borner GHH, Chazin WJ, Robinson MS, Jackson LP. Molecular Basis for the Interaction Between AP4 β4 and its Accessory Protein, Tepsin. Traffic 2016; 17:400-15. [PMID: 26756312 PMCID: PMC4805503 DOI: 10.1111/tra.12375] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 01/07/2016] [Accepted: 01/07/2016] [Indexed: 01/08/2023]
Abstract
The adaptor protein 4 (AP4) complex (ϵ/β4/μ4/σ4 subunits) forms a non-clathrin coat on vesicles departing the trans-Golgi network. AP4 biology remains poorly understood, in stark contrast to the wealth of molecular data available for the related clathrin adaptors AP1 and AP2. AP4 is important for human health because mutations in any AP4 subunit cause severe neurological problems, including intellectual disability and progressive spastic para- or tetraplegias. We have used a range of structural, biochemical and biophysical approaches to determine the molecular basis for how the AP4 β4 C-terminal appendage domain interacts with tepsin, the only known AP4 accessory protein. We show that tepsin harbors a hydrophobic sequence, LFxG[M/L]x[L/V], in its unstructured C-terminus, which binds directly and specifically to the C-terminal β4 appendage domain. Using nuclear magnetic resonance chemical shift mapping, we define the binding site on the β4 appendage by identifying residues on the surface whose signals are perturbed upon titration with tepsin. Point mutations in either the tepsin LFxG[M/L]x[L/V] sequence or in its cognate binding site on β4 abolish in vitro binding. In cells, the same point mutations greatly reduce the amount of tepsin that interacts with AP4. However, they do not abolish the binding between tepsin and AP4 completely, suggesting the existence of additional interaction sites between AP4 and tepsin. These data provide one of the first detailed mechanistic glimpses at AP4 coat assembly and should provide an entry point for probing the role of AP4-coated vesicles in cell biology, and especially in neuronal function.
Collapse
Affiliation(s)
- Meredith N Frazier
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
| | - Alexandra K Davies
- Department of Clinical Biochemistry, Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge, UK
| | - Markus Voehler
- Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
- Department of Biochemistry and Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Amy K Kendall
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
| | - Georg H H Borner
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Walter J Chazin
- Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
- Department of Biochemistry and Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Margaret S Robinson
- Department of Clinical Biochemistry, Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge, UK
| | - Lauren P Jackson
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
| |
Collapse
|
9
|
Szulik MW, Pallan PS, Nocek B, Voehler M, Banerjee S, Brooks S, Joachimiak A, Egli M, Eichman BF, Stone MP. Correction to differential stabilities and sequence-dependent base pair opening dynamics of watson-crick base pairs with 5-hydroxymethylcytosine, 5-formylcytosine, or 5-carboxylcytosine. Biochemistry 2015; 54:2550. [PMID: 25860080 PMCID: PMC4533905 DOI: 10.1021/acs.biochem.5b00344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
10
|
Wu J, Peng D, Zhang Y, Lu Z, Voehler M, Sanders CR, Li J. Biophysical characterization of interactions between the C-termini of peripheral nerve claudins and the PDZ₁ domain of zonula occludens. Biochem Biophys Res Commun 2015; 459:87-93. [PMID: 25712527 DOI: 10.1016/j.bbrc.2015.02.075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 02/14/2015] [Indexed: 11/30/2022]
Abstract
Our recent study has shown that cellular junctions in myelin and in the epi-/perineruium that encase nerve fibers regulate the permeability of the peripheral nerves. This permeability may affect propagation of the action potential. Direct interactions between the PDZ₁ domain of zonula occludens (ZO₁ or ZO₂) and the C-termini of claudins are known to be crucial for the formation of tight junctions. Using the purified PDZ₁ domain of ZO₂ and a variety of C-terminal mutants of peripheral nerve claudins (claudin-1, claudin-2, claudin-3, claudin-5 in epi-/perineurium; claudin-19 in myelin), we have utilized NMR spectroscopy to determine specific roles of the 3 C-terminal claudin residues (position -2, -1, 0) for their interactions with PDZ₁ of ZO₂. In contrast to the canonical model that emphasizes the importance of residues at the -2 and 0 positions, our results demonstrate that, for peripheral nerve claudins, the residue at position -1 plays a critical role in association with PDZ₁, while the side-chain of residue 0 plays a significant but lesser role. Surprisingly, claudin-19, the most abundant claudin in myelin, exhibited no binding to ZO₂. These findings reveal that the binding mechanism of claudin/ZO in epi-/perineurium is distinct from the canonical interactions between non-ZO PDZ-containing proteins with their ligands. This observation provides the molecular basis for a strategy to develop drugs that target tight junctions in the epi-/perineurium of peripheral nerves.
Collapse
Affiliation(s)
- Jiawen Wu
- Department of Neurology, Vanderbilt University School of Medicine, USA; Anhui University of Chinese Medicine, Hefei, Anhui, China
| | - Dungeng Peng
- Department of Neurology, Vanderbilt University School of Medicine, USA
| | - Yang Zhang
- Department of Neurology, Vanderbilt University School of Medicine, USA
| | - Zhenwei Lu
- Department of Biochemistry, Vanderbilt University School of Medicine, USA
| | - Markus Voehler
- Center for Structural Biology, Vanderbilt University, USA
| | - Charles R Sanders
- Department of Biochemistry, Vanderbilt University School of Medicine, USA; Center for Structural Biology, Vanderbilt University, USA
| | - Jun Li
- Department of Neurology, Vanderbilt University School of Medicine, USA; Tennessee Valley Healthcare System (TVHS), Nashville, VA, USA; Center for Human Genetics Research, Vanderbilt University School of Medicine, USA.
| |
Collapse
|
11
|
Szulik M, Pallan PS, Nocek B, Voehler M, Banerjee S, Brooks S, Joachimiak A, Egli M, Eichman BF, Stone MP. Differential stabilities and sequence-dependent base pair opening dynamics of Watson-Crick base pairs with 5-hydroxymethylcytosine, 5-formylcytosine, or 5-carboxylcytosine. Biochemistry 2015; 54:1294-305. [PMID: 25632825 PMCID: PMC4325598 DOI: 10.1021/bi501534x] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
5-Hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC) form during active demethylation of 5-methylcytosine (5mC) and are implicated in epigenetic regulation of the genome. They are differentially processed by thymine DNA glycosylase (TDG), an enzyme involved in active demethylation of 5mC. Three modified Dickerson-Drew dodecamer (DDD) sequences, amenable to crystallographic and spectroscopic analyses and containing the 5'-CG-3' sequence associated with genomic cytosine methylation, containing 5hmC, 5fC, or 5caC placed site-specifically into the 5'-T(8)X(9)G(10)-3' sequence of the DDD, were compared. The presence of 5caC at the X(9) base increased the stability of the DDD, whereas 5hmC or 5fC did not. Both 5hmC and 5fC increased imino proton exchange rates and calculated rate constants for base pair opening at the neighboring base pair A(5):T(8), whereas 5caC did not. At the oxidized base pair G(4):X(9), 5fC exhibited an increase in the imino proton exchange rate and the calculated kop. In all cases, minimal effects to imino proton exchange rates occurred at the neighboring base pair C(3):G(10). No evidence was observed for imino tautomerization, accompanied by wobble base pairing, for 5hmC, 5fC, or 5caC when positioned at base pair G(4):X(9); each favored Watson-Crick base pairing. However, both 5fC and 5caC exhibited intranucleobase hydrogen bonding between their formyl or carboxyl oxygens, respectively, and the adjacent cytosine N(4) exocyclic amines. The lesion-specific differences observed in the DDD may be implicated in recognition of 5hmC, 5fC, or 5caC in DNA by TDG. However, they do not correlate with differential excision of 5hmC, 5fC, or 5caC by TDG, which may be mediated by differences in transition states of the enzyme-bound complexes.
Collapse
Affiliation(s)
- Marta
W. Szulik
- Department
of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt
Ingram Cancer Center, and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Pradeep S. Pallan
- Department
of Biochemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt
Ingram Cancer Center, and Center for Structural Biology, School of
Medicine, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Boguslaw Nocek
- Bioscience
Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Markus Voehler
- Department
of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt
Ingram Cancer Center, and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Surajit Banerjee
- Northeastern
Collaborative Access Team and Department of Chemistry and Chemical
Biology, Cornell University, Argonne National
Laboratory, Argonne, Illinois 60439, United
States
| | - Sonja Brooks
- Department
of Biological Sciences, Vanderbilt Institute of Chemical Biology,
and Center for Structural Biology, Vanderbilt
University, Nashville, Tennessee 37235, United States
| | - Andrzej Joachimiak
- Bioscience
Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Martin Egli
- Department
of Biochemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt
Ingram Cancer Center, and Center for Structural Biology, School of
Medicine, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Brandt F. Eichman
- Department
of Biological Sciences, Vanderbilt Institute of Chemical Biology,
and Center for Structural Biology, Vanderbilt
University, Nashville, Tennessee 37235, United States
| | - Michael P. Stone
- Department
of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt
Ingram Cancer Center, and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37235, United States,(M.P.S.) Tel.: 615-322-2589; E-mail:
| |
Collapse
|
12
|
Abstract
Base pairing in nucleic acids plays a crucial role in their structure and function. Differences in the base-pair opening and closing kinetics of individual double-stranded DNA sequences or between chemically modified base pairs provide insight into the recognition of these base pairs by DNA processing enzymes. This unit describes how to quantify the kinetics for localized base pairs by observing changes in the imino proton signals by nuclear magnetic resonance spectroscopy. The determination of all relevant parameters using state-of-the art techniques and NMR instrumentation, including cryoprobes, is discussed.
Collapse
Affiliation(s)
- Marta W Szulik
- Department of Chemistry and Center for Structural Biology, Vanderbilt University, Nashville, Tennesee; These authors contributed equally to this work
| | | | | |
Collapse
|
13
|
Collier SE, Voehler M, Peng D, Ohi R, Gould KL, Reiter NJ, Ohi MD. Structural and functional insights into the N-terminus of Schizosaccharomyces pombe Cdc5. Biochemistry 2014; 53:6439-51. [PMID: 25263959 PMCID: PMC4204884 DOI: 10.1021/bi5008639] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
![]()
The
spliceosome is a dynamic macromolecular machine composed of
five small nuclear ribonucleoparticles (snRNPs), the NineTeen Complex
(NTC), and other proteins that catalyze the removal of introns mature
to form the mature message. The NTC, named after its founding member Saccharomyces cerevisiae Prp19, is a conserved spliceosome
subcomplex composed of at least nine proteins. During spliceosome
assembly, the transition to an active spliceosome correlates with
stable binding of the NTC, although the mechanism of NTC function
is not understood. Schizosaccharomyces pombe Cdc5, a core subunit of the NTC, is an essential protein required
for pre-mRNA splicing. The highly conserved Cdc5 N-terminus contains
two canonical Myb (myeloblastosis) repeats (R1 and R2) and a third
domain (D3) that was previously classified as a Myb-like repeat. Although
the N-terminus of Cdc5 is required for its function, how R1, R2, and
D3 each contribute to functionality is unclear. Using a combination
of yeast genetics, structural approaches, and RNA binding assays,
we show that R1, R2, and D3 are all required for the function of Cdc5
in cells. We also show that the N-terminus of Cdc5 binds RNA in vitro. Structural and functional analyses of Cdc5-D3
show that, while this domain does not adopt a Myb fold, Cdc5-D3 preferentially
binds double-stranded RNA. Our data suggest that the Cdc5 N-terminus
interacts with RNA structures proposed to be near the catalytic core
of the spliceosome.
Collapse
Affiliation(s)
- Scott E Collier
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center , Nashville, Tennessee 37232, United States
| | | | | | | | | | | | | |
Collapse
|
14
|
Collier SE, Peng D, Voehler M, Reiter N, Ohi M. Characterizing the Structure and Function of the N-Terminus of Schizosaccharomyces Pombe Cdc5, a Pre-Mrna Splicing Factor. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.2417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
|
15
|
Wu J, Peng D, Voehler M, Sanders CR, Li J. Structure and expression of a novel compact myelin protein - small VCP-interacting protein (SVIP). Biochem Biophys Res Commun 2013; 440:173-8. [PMID: 24055875 PMCID: PMC3828079 DOI: 10.1016/j.bbrc.2013.09.056] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 09/10/2013] [Indexed: 11/24/2022]
Abstract
SVIP (small p97/VCP-interacting protein) was initially identified as one of many cofactors regulating the valosin containing protein (VCP), an AAA+ ATPase involved in endoplasmic-reticulum-associated protein degradation (ERAD). Our previous study showed that SVIP is expressed exclusively in the nervous system. In the present study, SVIP and VCP were seen to be co-localized in neuronal cell bodies. Interestingly, we also observed that SVIP co-localizes with myelin basic protein (MBP) in compact myelin, where VCP was absent. Furthermore, using nuclear magnetic resonance (NMR) and circular dichroism (CD) spectroscopic measurements, we determined that SVIP is an intrinsically disordered protein (IDP). However, upon binding to the surface of membranes containing a net negative charge, the helical content of SVIP increases dramatically. These findings provide structural insight into interactions between SVIP and myelin membranes.
Collapse
Affiliation(s)
- Jiawen Wu
- Department of Neurology, Vanderbilt University School of Medicine
| | - Dungeng Peng
- Department of Biochemistry, Vanderbilt University School of Medicine
| | | | - Charles R. Sanders
- Department of Biochemistry, Vanderbilt University School of Medicine
- Center for Structural Biology, Vanderbilt University
| | - Jun Li
- Department of Neurology, Vanderbilt University School of Medicine
- Tennessee Valley Healthcare System (TVHS) – Nashville VA
| |
Collapse
|
16
|
Brash AR, Boeglin WE, Stec DF, Voehler M, Schneider C, Cha JK. Isolation and characterization of two geometric allene oxide isomers synthesized from 9S-hydroperoxylinoleic acid by cytochrome P450 CYP74C3: stereochemical assignment of natural fatty acid allene oxides. J Biol Chem 2013; 288:20797-20806. [PMID: 23709224 DOI: 10.1074/jbc.m113.482521] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Specialized cytochromes P450 or catalase-related hemoproteins transform fatty acid hydroperoxides to allene oxides, highly reactive epoxides leading to cyclopentenones and other products. The stereochemistry of the natural allene oxides is incompletely defined, as are the structural features required for their cyclization. We investigated the transformation of 9S-hydroperoxylinoleic acid with the allene oxide synthase CYP74C3, a reported reaction that unexpectedly produces an allene oxide-derived cyclopentenone. Using biphasic reaction conditions at 0 °C, we isolated the initial products and separated two allene oxide isomers by HPLC at -15 °C. One matched previously described allene oxides in its UV spectrum (λmax 236 nm) and NMR spectrum (defining a 9,10-epoxy-octadec-10,12Z-dienoate). The second was a novel stereoisomer (UV λmax 239 nm) with distinctive NMR chemical shifts. Comparison of NOE interactions of the epoxy proton at C9 in the two allene oxides (and the equivalent NOE experiment in 12,13-epoxy allene oxides) allowed assignment at the isomeric C10 epoxy-ene carbon as Z in the new isomer and the E configuration in all previously characterized allene oxides. The novel 10Z isomer spontaneously formed a cis-cyclopentenone at room temperature in hexane. These results explain the origin of the cyclopentenone, provide insights into the mechanisms of allene oxide cyclization, and define the double bond geometry in naturally occurring allene oxides.
Collapse
Affiliation(s)
| | | | - Donald F Stec
- Chemistry and the Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232 and
| | - Markus Voehler
- Chemistry and the Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232 and
| | | | - Jin K Cha
- the Department of Chemistry, Wayne State University, Detroit, Michigan 48202
| |
Collapse
|
17
|
Petrova KV, Stec DF, Voehler M, Rizzo CJ. Synthesis of the four stereoisomers of 2,3-epoxy-4-hydroxynonanal and their reactivity with deoxyguanosine. Org Biomol Chem 2011; 9:1960-71. [PMID: 21258716 DOI: 10.1039/c0ob00546k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
2,3-Epoxy-4-hydroxynonanal (EHN) is a potential product of lipid peroxidation that gives rise to genotoxic etheno adducts. We have synthesized all four stereoisomers of EHN and individually reacted them with 2'-deoxyguanosine. In addition to 1,N(2)-etheno-2'-deoxyguanosine, 12 stereoisomeric products were isolated and characterized by (1)H NMR and circular dichroism spectroscopy. The stereochemical assignments were consistent with selective NOE spectra, vicinal coupling constants, and molecular mechanics calculations. Reversed-phase HPLC conditions were developed that could separate most of the adduct mixture.
Collapse
Affiliation(s)
- Katya V Petrova
- Department of Chemistry, Center in Molecular Toxicology, Vanderbilt University, VU Station B 351822, Nashville, Tennessee, 37235-1822, USA
| | | | | | | |
Collapse
|
18
|
Abstract
Collagen IV networks are ancient proteins of basement membranes that underlie epithelia in metazoa from sponge to human. The networks provide structural integrity to tissues and serve as ligands for integrin cell-surface receptors. They are assembled by oligomerization of triple-helical protomers and are covalently crosslinked, a key reinforcement that stabilizes networks. We used Fourier-transform ion cyclotron resonance mass spectrometry and nuclear magnetic resonance spectroscopy to show that a sulfilimine bond (-S=N-) crosslinks hydroxylysine-211 and methionine-93 of adjoining protomers, a bond not previously found in biomolecules. This bond, the nitrogen analog of a sulfoxide, appears to have arisen at the divergence of sponge and cnidaria, an adaptation of the extracellular matrix in response to mechanical stress in metazoan evolution.
Collapse
Affiliation(s)
- Roberto Vanacore
- Department of Medicine and Center for Matrix Biology, Vanderbilt University, Nashville TN 37232, USA
| | - Amy-Joan L. Ham
- Department of Biochemistry, Vanderbilt University, Nashville TN 37232, USA
| | - Markus Voehler
- Department of Chemistry, Vanderbilt University, Nashville TN 37232, USA
| | - Charles R. Sanders
- Department of Biochemistry, Vanderbilt University, Nashville TN 37232, USA
| | - Thomas P. Conrads
- Laboratory of Proteomics and Analytical Technologies, Advanced Technology Program, SAIC-Frederick, Inc., NCI at Frederick, MD 21702
| | - Timothy D. Veenstra
- Laboratory of Proteomics and Analytical Technologies, Advanced Technology Program, SAIC-Frederick, Inc., NCI at Frederick, MD 21702
| | - K. Barry Sharpless
- Department of Chemistry and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Philip E. Dawson
- Department of Chemistry and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Billy G. Hudson
- Department of Medicine and Center for Matrix Biology, Vanderbilt University, Nashville TN 37232, USA
- Department of Biochemistry, Vanderbilt University, Nashville TN 37232, USA
- Department of Pathology, Vanderbilt University, Nashville TN 37232, USA
| |
Collapse
|
19
|
Abstract
Oxidative damage is considered a major contributing factor to genetic diseases including cancer. Our laboratory is evaluating endogenously formed DNA adducts as genomic biomarkers of oxidative injury. Recent efforts have focused on investigating the metabolic stability of adducts in vitro and in vivo. Here, we demonstrate that the base adduct, M1G, undergoes oxidative metabolism in vitro in rat liver cytosol (RLC, Km = 105 microM and vmax/Km = 0.005 min-1 mg-1) and in vivo when administered intravenously to male Sprague Dawley rats. LC-MS analysis revealed two metabolites containing successive additions of 16 amu. One- and two-dimensional NMR experiments showed that oxidation occurred first at the 6-position of the pyrimido ring, forming 6-oxo-M1G, and then at the 2-position of the imidazole ring, yielding 2,6-dioxo-M1G. Authentic 6-oxo-M1G was chemically synthesized and observed to undergo metabolism to 2,6-dioxo-M1G in RLC (Km = 210 microM and vmax/Km = 0.005 min-1 mg-1). Allopurinol partially inhibited M1G metabolism (75%) and completely inhibited 6-oxo-M1G metabolism in RLC. These inhibition studies suggest that xanthine oxidase is the principal enzyme acting on M1G in RLC and the only enzyme that converts 6-oxo-M1G to 2,6-dioxo-M1G. Both M1G and 6-oxo-M1G are better substrates (5-fold) for oxidative metabolism in RLC than the deoxynucleoside, M1dG. Alternative repair pathways or biological processing of M1dG makes the fate of M1G of interest as a potential marker of oxidative damage in vivo.
Collapse
Affiliation(s)
- Charles G Knutson
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, USA
| | | | | | | | | | | |
Collapse
|
20
|
Cho YJ, Wang H, Kozekov ID, Kozekova A, Kurtz AJ, Jacob J, Voehler M, Smith J, Harris TM, Rizzo CJ, Lloyd RS, Stone MP. Orientation of the crotonaldehyde-derived N2-[3-Oxo-1(S)-methyl-propyl]-dG DNA adduct hinders interstrand cross-link formation in the 5'-CpG-3' sequence. Chem Res Toxicol 2006; 19:1019-29. [PMID: 16918240 DOI: 10.1021/tx0600604] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The conformation of the crotonaldehyde-derived N(2)-[3-oxo-1(S)-methyl-propyl]-dG adduct in the oligodeoxynucleotide 5'-d(G(1)C(2)T(3)A(4)G(5)C(6)X(7)A(8)G(9)T(10)C(11)C(12))-3'.5'-d(G(13)G(14)A(15)C(16)T(17)C(18)G(19)C(20)T(21)A(22)G(23)C(2)(4))-3', where X = N(2)-[3-oxo-1(S)-methyl-propyl]-dG, is reported. This adduct arises from opening of the cyclic N(2)-(S-alpha-CH(3)-gamma-OH-1,N(2)-propano-2')-dG adduct when placed opposite dC in duplex DNA. This oligodeoxynucleotide contains the 5'-CpG-3' sequence in which the N(2)-(R-alpha-CH(3)-gamma-OH-1,N(2)-propano-2')-dG but not the N(2)-(S-alpha-CH(3)-gamma-OH-1,N(2)-propano-2')-dG adduct preferentially formed an interstrand carbinolamine cross-link [Kozekov, I. D., Nechev, L. V., Moseley, M. S., Harris, C. M., Rizzo, C. J., Stone, M. P., and Harris, T. M. (2003) J. Am. Chem. Soc. 125, 50-61; Cho, Y.-J., Wang, H., Kozekov, I. D., Kurtz, A. J., Jacob, J., Voehler, M., Smith, J., Harris, T. M., Lloyd, R. S., Rizzo, C. J., and Stone, M. P. (2006) Chem. Res. Toxicol. 19, 195-208]. Analysis of (1)H NOE data, chemical shift perturbations, and deoxyribose pseudorotations and backbone torsion angles suggested the presence of a stable and ordered DNA conformation at pH 9.3 and 30 degrees C, with minimal conformational perturbation. The spectral line widths of the adduct protons were comparable to those of the oligodeoxynucleotide, suggesting that the correlation times of these protons were similar to those of the overall duplex. The crotonaldehydic-derived methyl protons showed NOEs in the 5'-direction to C(18) H1', G(19) H1', and G(19) H4' in the complementary strand of the duplex. The aldehyde proton of the adduct exhibited NOEs in the 3'-direction to A(8) H1' and A(8) H4' in the modified strand. All of these NOEs involved DNA protons facing the minor groove. Molecular dynamics calculations, restrained by distances and torsion angles derived from the NMR data, revealed that within the minor groove, the aldehyde of the N(2)-[3-oxo-1(S)-methyl-propyl]-dG adduct oriented in the 3'-direction, while the 1(S) methyl group oriented in the 5'-direction. This positioned the aldehyde distal to the G(19) exocyclic amine and provided a rationale as to why the N(2)-(S-alpha-CH(3)-gamma-OH-1,N(2)-propano-2')-dG adduct generated interstrand cross-links less efficiently than did the N(2)-(R-alpha-CH(3)-gamma-OH-1,N(2)-propano-2')-dG adduct.
Collapse
Affiliation(s)
- Young-Jin Cho
- Department of Chemistry, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Abstract
5-Lipoxygenase and cyclooxygenase-2 (COX-2) initiate the biosynthesis of distinct families of mediators from arachidonic acid (leukotrienes and prostaglandins, respectively) and are each the target of anti-inflammatory medications. Here we show that the product of 5-lipoxygenase, 5S-hydroxyeicosatetraenoic acid, is selectively and efficiently triply oxygenated by COX-2, implicating a cross-pathway interaction. The product is a unique diendoperoxide, potentially representing the parent compound of a novel group of lipid mediators.
Collapse
Affiliation(s)
- Claus Schneider
- Department of Pharmacology, Division of Clinical Pharmacology, 23rd Avenue South at Pierce, Vanderbilt University Medical School, Nashville, Tennessee 37232, USA.
| | | | | | | | | |
Collapse
|
22
|
Cho YJ, Kim HY, Huang H, Slutsky A, Minko IG, Wang H, Nechev LV, Kozekov ID, Kozekova A, Tamura P, Jacob J, Voehler M, Harris TM, Lloyd RS, Rizzo CJ, Stone MP. Spectroscopic characterization of interstrand carbinolamine cross-links formed in the 5'-CpG-3' sequence by the acrolein-derived gamma-OH-1,N2-propano-2'-deoxyguanosine DNA adduct. J Am Chem Soc 2006; 127:17686-96. [PMID: 16351098 PMCID: PMC2631571 DOI: 10.1021/ja053897e] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The interstrand N2,N2-dG DNA cross-linking chemistry of the acrolein-derived gamma-OH-1,N2-propanodeoxyguanosine (gamma-OH-PdG) adduct in the 5'-CpG-3' sequence was monitored within a dodecamer duplex by NMR spectroscopy, in situ, using a series of site-specific 13C- and 15N-edited experiments. At equilibrium 40% of the DNA was cross-linked, with the carbinolamine form of the cross-link predominating. The cross-link existed in equilibrium with the non-crosslinked N2-(3-oxo-propyl)-dG aldehyde and its geminal diol hydrate. The ratio of aldehyde/diol increased at higher temperatures. The 1,N2-dG cyclic adduct was not detected. Molecular modeling suggested that the carbinolamine linkage should be capable of maintaining Watson-Crick hydrogen bonding at both of the tandem C x G base pairs. In contrast, dehydration of the carbinolamine cross-link to an imine (Schiff base) cross-link, or cyclization of the latter to form a pyrimidopurinone cross-link, was predicted to require disruption of Watson-Crick hydrogen bonding at one or both of the tandem cross-linked C x G base pairs. When the gamma-OH-PdG adduct contained within the 5'-CpG-3' sequence was instead annealed into duplex DNA opposite T, a mixture of the 1,N2-dG cyclic adduct, the aldehyde, and the diol, but no cross-link, was observed. With this mismatched duplex, reaction with the tetrapeptide KWKK formed DNA-peptide cross-links efficiently. When annealed opposite dA, gamma-OH-PdG remained as the 1,N2-dG cyclic adduct although transient epimerization was detected by trapping with the peptide KWKK. The results provide a rationale for the stability of interstrand cross-links formed by acrolein and perhaps other alpha,beta-unsaturated aldehydes. These sequence-specific carbinolamine cross-links are anticipated to interfere with DNA replication and contribute to acrolein-mediated genotoxicity.
Collapse
Affiliation(s)
- Young-Jin Cho
- Department of Chemistry, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Cho YJ, Wang H, Kozekov ID, Kurtz AJ, Jacob J, Voehler M, Smith J, Harris TM, Lloyd RS, Rizzo CJ, Stone MP. Stereospecific formation of interstrand carbinolamine DNA cross-links by crotonaldehyde- and acetaldehyde-derived alpha-CH3-gamma-OH-1,N2-propano-2'-deoxyguanosine adducts in the 5'-CpG-3' sequence. Chem Res Toxicol 2006; 19:195-208. [PMID: 16485895 PMCID: PMC2631444 DOI: 10.1021/tx050239z] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The crotonaldehyde- and acetaldehyde-derived R- and S-alpha-CH3-gamma-OH-1,N2-propanodeoxyguanosine adducts were monitored in single-stranded and duplex oligodeoxynucleotides using NMR spectroscopy. In both instances, the cis and trans diastereomers of the alpha-CH3 and gamma-OH groups underwent slow exchange, with the trans diastereomers being favored. In single-stranded oligodeoxynucleotides, the aldehyde intermediates were not detected spectroscopically, but their presence was revealed through the formation of N-terminal conjugates with the tetrapeptide KWKK. When annealed into 5'-d(GCTAGCXAGTCC)-3'.5'-d(GGACTCYCTAGC)-3' containing the 5'-CpG-3' sequence context (X = R- or S-alpha-CH3-gamma-13C-OH-PdG; Y = 15N2-dG) at pH 7, partial opening of the R- or S-alpha-CH3-gamma-13C-OH-PdG adducts to the corresponding N2-(3-oxo-1-methyl-propyl)-dG aldehydes was observed at temperatures below the T(m) of the duplexes. These aldehydes equilibrated with their geminal diol hydrates; higher temperatures favored the aldehydes. When annealed opposite T, the S-alpha-CH3-gamma-13C-OH-PdG adduct was stable. At 37 degrees C, an interstrand DNA cross-link was observed spectroscopically only for the R-alpha-CH3-gamma-OH-PdG adduct. Molecular modeling predicted that the interstrand cross-link formed by the R-alpha-CH3-gamma-OH-PdG adduct introduced less disruption into the duplex structure than did the cross-link arising from the S-alpha-CH3-gamma-OH-PdG adduct, due to differing orientations of the R- and S-CH3 groups. Modeling also predicted that the alpha-methyl group of the aldehyde arising from the R-alpha-CH3-gamma-OH-PdG adduct is oriented in the 3'-direction in the minor groove, facilitating cross-linking. In contrast, the alpha-methyl group of the aldehyde arising from the S-alpha-CH3-gamma-OH-PdG adduct is oriented in the 5'-direction within the minor groove, potentially hindering cross-linking. NMR revealed that for the R-alpha-CH3-gamma-OH-PdG adduct, the carbinolamine form of the cross-link was favored in duplex DNA with the imine (Schiff base) form of the cross-link remaining below the level of spectroscopic detection. Molecular modeling predicted that the carbinolamine linkage maintained Watson-Crick hydrogen bonding at both of the tandem C.G base pairs. Dehydration of the carbinolamine cross-link to an imine, or cyclization of the latter to form a pyrimidopurinone cross-link, required disruption of Watson-Crick hydrogen bonding at one or both of the cross-linked base pairs.
Collapse
Affiliation(s)
- Young-Jin Cho
- Department of Chemistry, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235
| | - Hao Wang
- Department of Chemistry, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235
| | - Ivan D. Kozekov
- Department of Chemistry, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235
| | | | | | - Markus Voehler
- Department of Chemistry, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235
| | - Jarrod Smith
- Department of Chemistry, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235
| | - Thomas M. Harris
- Department of Chemistry, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235
| | | | - Carmelo J. Rizzo
- Department of Chemistry, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235
| | - Michael P. Stone
- Department of Chemistry, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235
| |
Collapse
|
24
|
Zhao B, Guengerich FP, Voehler M, Waterman MR. Role of active site water molecules and substrate hydroxyl groups in oxygen activation by cytochrome P450 158A2: a new mechanism of proton transfer. J Biol Chem 2005; 280:42188-97. [PMID: 16239228 DOI: 10.1074/jbc.m509220200] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
From the x-ray crystal structure of CYP158A2 (Zhao, B., Guengerich, F. P., Bellamine, A., Lamb, D. C., Izumikawa, M., Lei, L., Podust, L. M., Sundaramoorthy, M., Reddy, L. M., Kelly, S. L., Kalaitzis, J. A., Stec, D., Voehler, M., Falck, J. R., Moore, B. S., Shimada, T., and Waterman, M. R. (2005) J. Biol. Chem. 280, 11599-11607), one of 18 cytochrome P450 (CYP) genes in the actinomycete Streptomyces coelicolor, ordered active site water molecules (WAT505, WAT600, and WAT640), and hydroxyl groups of the substrate flaviolin were proposed to participate in proton transfer and oxygen cleavage in this monooxygenase. To probe their roles in catalysis, we have studied the crystal structures of a substrate analogue (2-hydroxy-1,4-naphthoquinone) complex with ferric CYP158A2 (2.15 A) and the flaviolin ferrous dioxygen-bound CYP158A2 complex (1.8 A). Catalytic activity toward 2-hydroxy-1,4-naphthoquinone was approximately 70-fold less than with flaviolin. In the ferrous dioxygen-bound flaviolin complex, the three water molecules in the ferric flaviolin complex still occupy the same positions and form hydrogen bonds to the distal dioxygen atom. These findings suggest that CYP158A2 utilizes substrate hydroxyl groups to stabilize active site water and further assist in the iron-linked dioxygen activation. A continuous hydrogen-bonded water network connecting the active site to the protein surface (bulk solvent) not present in the other two ferrous dioxygen-bound P450 structures (CYP101A1/P450cam and CYP107A1/P450eryF) is proposed to participate in the proton-delivery cascade, leading to dioxygen bond scission. This ferrous-dioxygen structure suggests two classes of P450s based on the pathway of proton transfer, one using the highly conserved threonine in the I-helix (CYP101A1) and the other requiring hydroxyl groups of the substrate molecules either directly transferring protons (CYP107A1) or stabilizing a water pathway for proton transfer (CYP158A2).
Collapse
Affiliation(s)
- Bin Zhao
- Department of Biochemistry, Centers for Structural Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37235, USA.
| | | | | | | |
Collapse
|
25
|
Quisenberry KT, Smith JD, Voehler M, Stec DF, Hanusa TP, Brennessel WW. Trimethylsilylated Allyl Complexes of Nickel. The Stabilized Bis(π-allyl)nickel Complex [η3-1,3-(SiMe3)2C3H3]2Ni and Its Mono(π-allyl)NiX (X = Br, I) Derivatives. J Am Chem Soc 2005; 127:4376-87. [PMID: 15783220 DOI: 10.1021/ja044308s] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reaction of 2 equiv of K[1,3-(SiMe3)2C3H3] with NiBr2(dme) in THF at -78 degrees C produces the orange pi-allyl complex [1,3-(SiMe3)2C3H3]2Ni (1). Unlike the pyrophoric (C3H5)2Ni, the trimethylsilylated derivative only slowly decomposes in air (from hours to days). Both eclipsed (1a) and staggered (1b) conformations are found in solution; the eclipsed form irreversibly converts to the thermodynamically more stable staggered conformation when heated above 85 degrees C. Single-crystal X-ray structures obtained for both 1a and 1b confirm that the allyl ligands are bound in a trihapto manner to the metals and that trimethylsilyl substituents are in syn, anti arrangements. Density functional theory calculations performed on the bis(allyl)nickel complexes indicate that the substituents exert little effect on the basic metal-ligand geometries. Trimethylphosphine is converted to tetramethyltetraphosphane, (MeP)4, on reaction with 1. In toluene, 3-bromo-1,3-bis(trimethylsilyl)propene reacts with (COD)2Ni to produce the dimeric purple complex {[1,3-(SiMe3)2C3H3]NiBr}2 (2a). Both NMR and X-ray crystallographic data establish that the allyl ligands are staggered and that the trimethylsilyl substituents are in a syn, syn conformation. NMR data indicate that the reaction of one equivalent of 1 with Br2 in benzene produces an analogous complex (2b) with the allyl ligand substituents in a syn, anti configuration. When 1 equiv of 1 is treated with I2 in hexanes, the dark red dimeric complex {[1,3-(SiMe3)2C3H3]NiI}2 (3) is formed. Its X-ray crystal structure demonstrates that both eclipsed (3a) and staggered (3b) allyl conformation are present. The trimethylsilyl groups on the allyl ligands are in syn, anti arrangements in the two forms.
Collapse
Affiliation(s)
- Keith T Quisenberry
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA
| | | | | | | | | | | |
Collapse
|
26
|
Zhao B, Guengerich FP, Bellamine A, Lamb DC, Izumikawa M, Lei L, Podust LM, Sundaramoorthy M, Kalaitzis JA, Reddy LM, Kelly SL, Moore BS, Stec D, Voehler M, Falck JR, Shimada T, Waterman MR. Binding of two flaviolin substrate molecules, oxidative coupling, and crystal structure of Streptomyces coelicolor A3(2) cytochrome P450 158A2. J Biol Chem 2005; 280:11599-607. [PMID: 15659395 DOI: 10.1074/jbc.m410933200] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cytochrome P450 158A2 (CYP158A2) is encoded within a three-gene operon (sco1206-sco1208) in the prototypic soil bacterium Streptomyces coelicolor A3(2). This operon is widely conserved among streptomycetes. CYP158A2 has been suggested to produce polymers of flaviolin, a pigment that may protect microbes from UV radiation, in combination with the adjacent rppA gene, which encodes the type III polyketide synthase, 1,3,6,8-tetrahydroxynaphthalene synthase. Following cloning, expression, and purification of this cytochrome P450, we have shown that it can produce dimer and trimer products from the substrate flaviolin and that the structures of two of the dimeric products were established using mass spectrometry and multiple NMR methods. A comparison of the x-ray structures of ligand-free (1.75 angstroms) and flaviolin-bound (1.62 angstroms) forms of CYP158A2 demonstrates a major conformational change upon ligand binding that closes the entry into the active site, partly due to repositioning of the F and G helices. Particularly interesting is the presence of two molecules of flaviolin in the closed active site. The flaviolin molecules form a quasi-planar three-molecule stack including the heme of CYP158A2, suggesting that oxidative C-C coupling of these phenolic molecules leads to the production of flaviolin dimers.
Collapse
Affiliation(s)
- Bin Zhao
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Abstract
Human cytochrome P450 3A4 forms a series of minor testosterone hydroxylation products in addition to 6 beta-hydroxytestosterone, the major product. One of these, formed at the next highest rate after the 6 beta- and 2 beta-hydroxy products, was identified as 1 beta-hydroxytestosterone. This product was characterized from a mixture of testosterone oxidation products using an HPLC-solid phase extraction-cryoprobe NMR/time-of-flight mass spectrometry system, with an estimated total of approximately 6 microg of this product. Mass spectrometry established the formula as C(19)H(29)O(3) (MH(+) 305.2080). The 1-position of the added hydroxyl group was established by correlated spectroscopy and heteronuclear spin quantum correlation experiments, and the beta-stereochemistry of the added hydroxyl group was assigned with a nuclear Overhauser correlated spectroscopy experiment (1 alpha-H). Of several human P450s examined, only P450 3A4 formed this product. The product was also formed in human liver microsomes.
Collapse
Affiliation(s)
- Joel A Krauser
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, USA
| | | | | | | | | | | |
Collapse
|
28
|
Riggins JN, Pratt DA, Voehler M, Daniels JS, Marnett LJ. Kinetics and mechanism of the general-acid-catalyzed ring-closure of the malondialdehyde-DNA adduct, N2-(3-oxo-1-propenyl)deoxyguanosine (N2OPdG-), to 3-(2'-Deoxy-beta-D-erythro-pentofuranosyl)pyrimido[1,2-alpha]purin- 10(3H)-one (M1dG). J Am Chem Soc 2004; 126:10571-81. [PMID: 15327313 DOI: 10.1021/ja040010q] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
3-(2'-Deoxy-beta-D-erythro-pentofuranosyl)pyrimido[1,2-alpha]purin-10(3H)-one (M1dG) is the major product of the reaction of deoxyguanosine with malondialdehyde (MDA). M1dG blocks replication by DNA polymerases in vitro and is mutagenic in vivo. M1dG reacts with hydroxide to form the N2-(3-oxo-1-propenyl)deoxyguanosine anion (N2OPdG-). This reaction is pH-dependent and reverses under neutral and acidic conditions to form M1dG. Here we describe the kinetics and mechanism of the ring-closure reaction in both the nucleoside and oligonucleotides. Kinetic analysis of absorbance and fluorescence changes demonstrates that ring-closure is biphasic, leading to the rapid formation of an intermediate that slowly converts to M1dG in a general-acid-catalyzed reaction. The dependence of the rate of the rapid phase on pH reveals the pKa for protonated N2OPdG is 6.9. One-dimensional 1H NMR and DQF-COSY experiments identified two distinct intermediates, N2OPdG-H and 8-hydroxy-6,7-propenodeoxyguanosine (HO-Prene-dG), that are formed upon acidification of N2OPdG-. Characterization of ring-closure in single-stranded and in melted duplex oligonucleotides shows M1dG formation is also acid-catalyzed in single-stranded oligonucleotides and that the denaturation of an oligonucleotide duplex enhances ring-closure. This work details the complexity of ring-closure in the nucleoside and oligonucleotides and provides new insight into the role of duplex DNA in catalyzing ring-opening and ring-closing of M1dG and N2OPdG.
Collapse
Affiliation(s)
- James N Riggins
- Department of Biochemistry, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
| | | | | | | | | |
Collapse
|
29
|
Hashim MF, Riggins JN, Schnetz-Boutaud N, Voehler M, Stone MP, Marnett LJ. In vitro bypass of malondialdehyde-deoxyguanosine adducts: differential base selection during extension by the Klenow fragment of DNA polymerase I is the critical determinant of replication outcome. Biochemistry 2004; 43:11828-35. [PMID: 15362868 DOI: 10.1021/bi049360f] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The major malondialdehyde-derived adduct in DNA is 3-(2'-deoxy-beta-D-erythro-pentofuranosyl)pyrimido[1,2-alpha]purin-10(3H)-one (M(1)dG). M(1)dG undergoes hydrolytic ring opening in duplex DNA to 9-(2'-deoxy-beta-D-erythro-pentofuranosyl)-N(2)-(3-oxo-1-propenyl)guanine (N(2)OPdG). Template-primers were constructed containing M(1)dG or N(2)OPdG in a (CpG)(4) repeat sequence and replicated with the Klenow fragment of DNA polymerase I (Kf). Incorporation opposite the lesion and replication beyond the adduct sites by Kf was reduced compared to unadducted controls. The amount of bypass to full-length products was significantly greater with the acyclic adduct, N(2)OPdG, than with the cyclic adduct, M(1)dG. Sequence analysis indicated that the fully extended primers contained dC opposite both adducts when replication was conducted with Kf exo(+). In contrast, with Kf exo(-), primers extended past M(1)dG contained T opposite the adduct, but primers extended past N(2)OPdG contained dC opposite the adduct. Single nucleotide incorporation experiments indicated that Kf exo(-) incorporates all four nucleotides opposite M(1)dG or N(2)OPdG. Kf exo(+) removed dA, dG, and T opposite M(1)dG and N(2)OPdG but was much less active when dC was opposite the adduct. NMR studies on duplex DNA indicated that N(2)OPdG hydrogen bonds with dC in the complementary strand. The fact that base pairing can occur for the acyclic adduct may explain why N(2)OPdG is less blocking than M(1)dG. These results support in vivo findings that the ring-closed adduct, M(1)dG, is more mutagenic than the ring-opened adduct, N(2)OPdG. They also provide a detailed picture of in vitro replication in which the outcome is determined primarily by the selectivity of template-primer extension beyond rather than insertion opposite the adducts.
Collapse
Affiliation(s)
- Muhammed F Hashim
- Department of Biochemistry, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, Vanderbilt-Ingram Comprehensive Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, USA
| | | | | | | | | | | |
Collapse
|
30
|
Guengerich FP, Williams KM, Sutter TR, Hayes JD, Johnson WW, Arneson KO, Voehler M, Deng Z, Harris TM. Competing Reactions of Aflatoxin B1 Dialdehyde: Enzymatic Reduction versus Adduction with Lysine. ACTA ACUST UNITED AC 2003. [DOI: 10.1021/bk-2003-0865.ch012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Affiliation(s)
- F. Peter Guengerich
- Departments of Biochemistry and Chemistry and Center in Molecular Toxicology, Vanderbilt University, Nashville, TN 37232
| | - Kevin M. Williams
- Departments of Biochemistry and Chemistry and Center in Molecular Toxicology, Vanderbilt University, Nashville, TN 37232
| | - Thomas R. Sutter
- W. Harry Feinstone Center for Genomic Research, University of Memphis, Memphis, TN 38152
| | - John D. Hayes
- Biochemical Research Centre, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, Scotland, United Kingdom
| | - William W. Johnson
- Departments of Biochemistry and Chemistry and Center in Molecular Toxicology, Vanderbilt University, Nashville, TN 37232
| | - Kyle O. Arneson
- Departments of Biochemistry and Chemistry and Center in Molecular Toxicology, Vanderbilt University, Nashville, TN 37232
| | - Markus Voehler
- Departments of Biochemistry and Chemistry and Center in Molecular Toxicology, Vanderbilt University, Nashville, TN 37232
| | - Zhenwu Deng
- Departments of Biochemistry and Chemistry and Center in Molecular Toxicology, Vanderbilt University, Nashville, TN 37232
| | - Thomas M. Harris
- Departments of Biochemistry and Chemistry and Center in Molecular Toxicology, Vanderbilt University, Nashville, TN 37232
| |
Collapse
|
31
|
Otteneder M, Daniels JS, Voehler M, Marnett LJ. Development of a method for determination of the malondialdehyde-deoxyguanosine adduct in urine using liquid chromatography-tandem mass spectrometry. Anal Biochem 2003; 315:147-51. [PMID: 12689823 DOI: 10.1016/s0003-2697(02)00697-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A procedure is described for the quantification of the major malondialdehyde deoxyguanosine adduct, pyrimido[1,2-alpha]purin-10(3H)-one-deoxyribose (M(1)GdR) in urine. M(1)GdR is isolated from urine by a combination of C(18) solid-phase extraction and immunoaffinity chromatography. Sodium borohydride treatment reduces M(1)GdR to the 5,6-dihydro derivative, which is quantified by liquid chromatography-mass spectrometry. Authentic [7,9-15N,8-13C]M(1)GdR is added to urine as an internal standard. A detection limit of 50 fmol M(1)GdR/ml urine is achieved starting with 5 ml of urine. Analysis of urine samples from control rats or rats treated with CCl(4) indicates that the levels of M(1)GdR are below the detection limit of the assay. This method is easily adaptable to the analysis of M(1)GdR in DNA samples or biological fluids.
Collapse
Affiliation(s)
- Michael Otteneder
- Department of Biochemistry, Center in Molecular Toxicology, and Vanderbilt-Ingram Comprehensive Cancer Center, Vanderbilt University, Nashville, TN 37232, USA
| | | | | | | |
Collapse
|
32
|
Kim HYH, Voehler M, Harris TM, Stone MP. Detection of an interchain carbinolamine cross-link formed in a CpG sequence by the acrolein DNA adduct gamma-OH-1,N( 2)-propano-2'-deoxyguanosine. J Am Chem Soc 2002; 124:9324-5. [PMID: 12166998 DOI: 10.1021/ja020333r] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Spectroscopic evidence is presented for the formation of a carbinolamine interchain cross-link in 5'-CpG-3' sequences, arising from the acrolein adduct gamma-OH-PdG. This may be important in understanding biological processing of acrolein-induced DNA damage in CpG sequences.
Collapse
Affiliation(s)
- Hye-Young H Kim
- Department of Chemistry, Center in Molecular Toxicology, Vanderbilt University, Nashville, Tennessee 37235, USA
| | | | | | | |
Collapse
|
33
|
Guengerich FP, Voehler M, Williams KM, Deng Z, Harris TM. Structure of the aflatoxin B(1) dialdehyde adduct formed from reaction with methylamine. Chem Res Toxicol 2002; 15:793-8. [PMID: 12067246 DOI: 10.1021/tx0200055] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Amine conjugates of activated aflatoxin (AF) B(1) are formed in various systems, e.g., buffer amines and with protein lysine groups. Structures have been published in the literature, but the evidence is indirect in that (i) halogenated AFB(1) was usually used as the precursor and (ii) the assignment of the structure of the five-membered ring formed by cyclization is based on NMR chemical shifts. To better define these adducts and distinguish among several possibilities, we synthesized AFB(1) dialdehyde and reacted this with the surrogate methylamine at neutral pH, to simplify the system. The isolated product had the expected molecular ion (mass spectrometry) and showed pH-dependent UV spectra similar to those published for a lysine conjugate. Nuclear Overhauser enhanced spectroscopy (two-dimensional NMR, 800 MHz) of the sample (2H(2)O) showed proximity of the N-CH(3) protons only with a singlet at delta 4.10, assigned to the methylene of the added five-membered ring, but not to a delta 6.53 singlet assigned as the vinylic proton of that ring. All protons in the coumarin-furanone portion of the system were correlated to each other but not to those in the added five-membered ring. These experiments establish the structure as 2,3-dihydro-2-oxo-4-(1,2,3,4-tetrahydro-7-hydroxy-9-methoxy-3,4-dioxocyclopenta[c][1]benzopyran-6-yl)-1H-pyrrole-1-methane. The similarity of the reaction to that occurring in the reaction of AFB(1) dialdehyde with lysine and the agreement of the UV spectra suggest that this structure is applicable for the lysine analogue. The NMR results support the possible structure B of Sabbioni et al. [Sabbioni, G., Skipper, P. L., Buchi, G., and Tannenbaum, S. R. (1987) Carcinogenesis 8, 819-824] and the proposed structure 8 of Sabbioni [Sabbioni, G. (1990) Chem.-Biol. Interact. 75, 1-15] but not alternative proposals. Kinetic and mechanistic considerations of the reaction of lysine with AFB(1) dialdehyde are presented in the previous article in this issue [Guengerich, F. P., Arneson, K. O., Williams, K. M., Deng, Z., and Harris, T. M. (2002) Chem. Res. Toxicol. 15, 780-793].
Collapse
Affiliation(s)
- F Peter Guengerich
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University, Nashville, Tennessee 37232-0146, USA.
| | | | | | | | | |
Collapse
|
34
|
Abstract
Arylamines are mutagens and carcinogens and are thought to initiate tumors by forming adducts with DNA. The major adducts are C(8)-guanyl, and we have previously suggested a role for guanyl-N(7) intermediates in the formation process. N(7)-Aminoguanosine (Guo) was synthesized and characterized, with the position of the NH(2) at N7 established by two-dimensional rotating frame Overhauser enhancement NMR spectroscopy. In DMF, N(7)-NH(2)Guo formed C(8)-NH(2)Guo and the cyclic product C(8):5'-O-cycloGuo. In aqueous media, these products were formed along with 8-oxo-7,8-dihydroGuo, N(7)-NH(2)guanine, and a product characterized as a purine 8, 9-ring-opened derivative (N-aminoformamidopyrimidine). The rate of aqueous decomposition of N(7)-NH(2)Guo increased with pH, with a t(1/2) of 10 h at pH 7 and a t(1/2) of 2 h at pH 9. The rate of migration of NH(2) from N7 to C8 is fast enough to explain the formation of C(8)-NH(2)Guo from the reaction of 2, 4-dinitrophenoxyamine with Guo but not the formation of C(8)-(arylamino)Guo in the reaction of Guo with aryl hydroxylamine esters; however, the fluorenyl moiety may facilitate the proposed rearrangement by stabilizing an incipient negative charge in the transfer. In the reaction of Guo with N-hydroxy-2-aminofluorene and acetylsalicylic acid, a peak with the mass spectrum expected for N(7)-(2-aminofluorenyl)Guo was detected early in the reaction and was distinguished from C(8)-(2-aminofluorenyl)Guo. NMR experiments with [8-(13)C]Guo also provided some additional support for transient formation of N(7)-(2-aminofluorenyl)Guo. We conclude that a guanyl-N(7) intermediate is reasonable in the reaction of activated arylamines with nucleic acids, although an exact rate of transfer of an N(7)-arylamine group to the C8 position has not yet been quantified. The results provide an explanation for the numerous products associated with modification of DNA by activated arylamines. However, the contribution of "direct" reaction at the guanine C8 atom cannot be excluded.
Collapse
Affiliation(s)
- F P Guengerich
- Departments of Biochemistry and Chemistry and Center in Molecular Toxicology, Vanderbilt University, Nashville, Tennessee 37232, USA.
| | | | | | | |
Collapse
|
35
|
Feng B, Voehler M, Zhou L, Passarelli M, Harris CM, Harris TM, Stone MP. Major groove (S)-alpha-(N6-adenyl)styrene oxide adducts in an oligodeoxynucleotide containing the human N-ras codon 61 sequence: conformations of the S(61,2) and S(61,3) sequence isomers from 1H NMR. Biochemistry 1996; 35:7316-29. [PMID: 8652508 DOI: 10.1021/bi952526f] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The (S)-alpha-(N6-adenyl)styrene oxide adducts at positions X6 in d(CGGACXAGAAG). d(CTTCTTGTCCG) and X7 in d(CGGACAXGAAG).d(CTTCTTGTCCG), incorporating codons 60, 61 (underlined), and 62 of the human n-ras protooncogene, were examined by 1H NMR. These were the S(61,2) and S(61,3) adducts. Chemical shift perturbations were in the 3'-direction from the sites of adduction; upfield changes associated with the styrene aromatic ring current were noted for S-SOA6 H2 and H1', T16 N3H, H6, and CH3 resonances in the S(61,2) oligomer. In the S(61,3) oligomer, S-SOA7 H1', T16 H1', C15 N4Ha, and H5 shifted upfield. The styrene aromatic rings flipped rapidly on the NMR time scale; under these conditions the ortho and meta aromatic protons were equivalent. A sequence effect, in which the S(61,2) adduct equilibrated between two conformers, while the S(61,3) adduct exhibited only a single conformation, was observed. Potential energy minimization of the S(61,2) adduct major conformation yielded a structure in which the styrene ring was oriented in the 3'-direction and interacted primarily with the complementary strand. For the S(61,3) adduct, 291 restraints were obtained from NOE data at three mixing times using relaxation matrix analysis. The emergent structures refined to an average rms difference of 1.3 A, determined by pairwise analysis. These were compared to NOE intensity data; the calculated sixth root residual index was 9.2 x 10-2 at 250 ms. In the refined structure, the styrene ring was also oriented in the 3'-direction and interacted with the complementary strand. The minor conformation of the S(61,2) adduct was not identified. These results contrasted with the diastereomeric R(61,2) and R(61,3) adducts, which underwent slow ring flips on the NMR time scale and for which small sequence effects involving the minimum energy conformation of the styrene ring were observed.
Collapse
Affiliation(s)
- B Feng
- Center in Molecular Toxicology, Vanderbilt University, Nashville, Tennessee 37235, USA
| | | | | | | | | | | | | |
Collapse
|
36
|
Abstract
Eleven new pregnane ester glycosides have been isolated from the aerial parts of Stapelia variegata. Eight of the recognized compounds were established to possess the same trioside moiety, viz. 3-O-[3-O-methyl-6-deoxy-beta-D-allopyranosyl-(1-4)-beta-D- cymaropyranosyl-(1-4)-beta-D-cymaropyranoside]. These compounds were identified as: stavaroside A: 12-O-beta-angeloyl-20-O-benzoyl sarcostin; stavaroside B: 12-O-beta-angeloyl-20-O-tigloyl sarcostin; stavaroside C: 11 alpha-acetoxy 2 beta-benzoxy-3 beta,8 beta, 14 beta-trihydroxy-pregn-5-ene-20-one; stavaroside D: 11 alpha-acetoxy- 12 beta-tigloxy-3 beta,8 beta,14 beta-trihydroxy-pregn-5-ene-20-one; stavaroside E: 12-O-beta-benzoyl sarcostin; stavaroside F: 11 alpha-acetoxy-12 beta-acetoxy-3 beta,8 beta,14 beta-trihydroxy-pregn-5- ene-20-one; stavaroside G: 12-O-beta,20-O-diacetyl sarcostin and stavaroside H: 3 beta, 8 beta, 11 alpha, 12 beta, 14 beta-pentahydroxy-pregn-5- ene-20-one. The other three compounds were shown to possess the same tetraside sugar moiety, viz. 3-O-[beta-D-glucopyranosyl- (1-4)-3-O-methyl-6-deoxy-beta-D-allopyranosyl-(1-4)-beta-D-cymaropyra nosyl- (1-4)-beta-D-cymaropyranoside]. These compounds were identified as: stavaroside I: 1 alpha, 12 beta-angeloxy and benzoxy-3 beta,8 beta,14 beta-trihydroxy- pregn-5-ene-20-one; stavaroside J: 11 alpha-acetoxy-12 beta-benzoxy-3 beta, 8 beta,14 beta-trihydroxy-pregn-5-ene-20-one and stavaroside K: 11 alpha-acetoxy-12 beta-tigloxy-3 beta,8 beta,14 beta-trihydroxy-pregn-5-ene- 20-one. The structural elucidation of the isolated compounds was aided significantly on the basis of the chemical and spectral evidence. The decisive assignments of the ester positions were based on the Inverse Detected-Heteronuclear Multiple Bond Connectivity (HMBC) experiments.
Collapse
Affiliation(s)
- K A el Sayed
- Pharmacognosy Department, Faculty of Pharmacy, Mansoura University, Egypt
| | | | | | | | | | | | | |
Collapse
|