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Alawneh A, Wettasinghe AP, McMullen R, Seifi MO, Breton I, Slinker JD, Kuchta RD. A Redox-Reversible Switch of DNA Hydrogen Bonding and Structure. ACS APPLIED BIO MATERIALS 2024. [PMID: 38978451 DOI: 10.1021/acsabm.4c00529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Modulating molecular structure and function at the nanoscale drives innovation across wide-ranging technologies. Electrical control of the bonding of individual DNA base pairs endows DNA with precise nanoscale structural reconfigurability, benefiting efforts in DNA origami and actuation. Here, alloxazine DNA base surrogates were synthesized and incorporated into DNA duplexes to function as a redox-active switch of hydrogen bonding. Circular dichroism (CD) revealed that 24-mer DNA duplexes containing one or two alloxazines exhibited CD spectra and melting transitions similar to DNA with only canonical bases, indicating that the constructs adopt a B-form conformation. However, duplexes were not formed when four or more alloxazines were incorporated into a 24-mer strand. Thiolated duplexes incorporating alloxazines were self-assembled onto multiplexed gold electrodes and probed electrochemically. Square-wave voltammetry (SWV) revealed a substantial reduction peak centered at -0.272 V vs Ag/AgCl reference. Alternating between alloxazine oxidizing and reducing conditions modulated the SWV peak in a manner consistent with the formation and loss of hydrogen bonding, which disrupts the base pair stacking and redox efficiency of the DNA construct. These alternating signals support the assertion that alloxazine can function as a redox-active switch of hydrogen bonding, useful in controlling DNA and bioinspired assemblies.
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Affiliation(s)
- Ayman Alawneh
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Ashan P Wettasinghe
- Department of Physics, The University of Texas at Dallas, 800 West Campbell Road, SCI 10, Richardson, Texas 75080, United States
| | - Reema McMullen
- Department of Physics, The University of Texas at Dallas, 800 West Campbell Road, SCI 10, Richardson, Texas 75080, United States
| | - Melodee O Seifi
- Department of Physics, The University of Texas at Dallas, 800 West Campbell Road, SCI 10, Richardson, Texas 75080, United States
| | - Ivan Breton
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Jason D Slinker
- Department of Physics, The University of Texas at Dallas, 800 West Campbell Road, SCI 10, Richardson, Texas 75080, United States
- Department of Chemistry, The University of Texas at Dallas, 800 West Campbell Road, SCI 10, Richardson, Texas 75080 United States
- Department of Materials Science and Engineering, The University of Texas at Dallas, 800 West Campbell Road, SCI 10, Richardson, Texas 75080, United States
| | - Robert D Kuchta
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
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How an assembly factor enhances covalent FAD attachment to the flavoprotein subunit of complex II. J Biol Chem 2022; 298:102472. [PMID: 36089066 PMCID: PMC9557727 DOI: 10.1016/j.jbc.2022.102472] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/31/2022] [Accepted: 09/02/2022] [Indexed: 01/25/2023] Open
Abstract
The membrane-bound complex II family of proteins is composed of enzymes that catalyze succinate and fumarate interconversion coupled with reduction or oxidation of quinones within the membrane domain. The majority of complex II enzymes are protein heterotetramers with the different subunits harboring a variety of redox centers. These redox centers are used to transfer electrons between the site of succinate-fumarate oxidation/reduction and the membrane domain harboring the quinone. A covalently bound FAD cofactor is present in the flavoprotein subunit, and the covalent flavin linkage is absolutely required to enable the enzyme to oxidize succinate. Assembly of the covalent flavin linkage in eukaryotic cells and many bacteria requires additional protein assembly factors. Here, we provide mechanistic details for how the assembly factors work to enhance covalent flavinylation. Both prokaryotic SdhE and mammalian SDHAF2 enhance FAD binding to their respective apoprotein of complex II. These assembly factors also increase the affinity for dicarboxylates to the apoprotein-noncovalent FAD complex and stabilize the preassembly complex. These findings are corroborated by previous investigations of the roles of SdhE in enhancing covalent flavinylation in both bacterial succinate dehydrogenase and fumarate reductase flavoprotein subunits and of SDHAF2 in performing the same function for the human mitochondrial succinate dehydrogenase flavoprotein. In conclusion, we provide further insight into assembly factor involvement in building complex II flavoprotein subunit active site required for succinate oxidation.
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The roles of SDHAF2 and dicarboxylate in covalent flavinylation of SDHA, the human complex II flavoprotein. Proc Natl Acad Sci U S A 2020; 117:23548-23556. [PMID: 32887801 DOI: 10.1073/pnas.2007391117] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mitochondrial complex II, also known as succinate dehydrogenase (SDH), is an integral-membrane heterotetramer (SDHABCD) that links two essential energy-producing processes, the tricarboxylic acid (TCA) cycle and oxidative phosphorylation. A significant amount of information is available on the structure and function of mature complex II from a range of organisms. However, there is a gap in our understanding of how the enzyme assembles into a functional complex, and disease-associated complex II insufficiency may result from incorrect function of the mature enzyme or from assembly defects. Here, we investigate the assembly of human complex II by combining a biochemical reconstructionist approach with structural studies. We report an X-ray structure of human SDHA and its dedicated assembly factor SDHAF2. Importantly, we also identify a small molecule dicarboxylate that acts as an essential cofactor in this process and works in synergy with SDHAF2 to properly orient the flavin and capping domains of SDHA. This reorganizes the active site, which is located at the interface of these domains, and adjusts the pKa of SDHAR451 so that covalent attachment of the flavin adenine dinucleotide (FAD) cofactor is supported. We analyze the impact of disease-associated SDHA mutations on assembly and identify four distinct conformational forms of the complex II flavoprotein that we assign to roles in assembly and catalysis.
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Tasca F, Fierro A, Nöll G. Spectroelectrochemical study revealing the redox potential of human monoamine oxidase A. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2019.06.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Khan FA, Campbell AJ, Hoyt B, Herdman C, Ku T, Thangavelu S, Gordon RK. Oxidative mechanisms for the biotransformation of 1-methyl-1,6-dihydropyridine-2-carbaldoxime to pralidoxime chloride. Life Sci 2011; 89:911-7. [PMID: 21989207 DOI: 10.1016/j.lfs.2011.09.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 08/02/2011] [Accepted: 09/13/2011] [Indexed: 01/02/2023]
Abstract
AIMS Due to pralidoxime chloride's (2-PAM) positive charge, it's penetration through the blood brain barrier (BBB) and reactivation of organophosphate (OP) inhibited central nervous system (CNS) acetylcholinesterase (AChE) is poor. The results of CNS inhibited AChE are seizures. Pro-2-PAM (1-methyl-1,6-dihydropyridine-2-carbaldoxime), a pro-drug of 2-PAM, due to higher hydrophobicity, penetrates the BBB better but must be oxidized to 2-PAM, the active form of the oxime to reactivate CNS AChE in order to abrogate seizures. In this study, we characterize the in vivo mechanism of pro-2-PAM oxidation. MAIN METHODS A high pressure liquid chromatography (HPLC) assay was developed to quantify the conversion of pro-2-PAM to 2-PAM. NADPH oxidase activity was measured by a photo-luminescence assay using lucigenin substrate. Upon analysis, the rate of NADPH induced oxidation suggested that an alternate mechanism may be involved. Therefore, various enzyme co-factors of oxidation-reduction enzyme systems were evaluated, including nicotinamide adenine dinucleotide (NAD), nicotinamide adenine dinucleotide phosphate (NADP), flavin adenine dinucleotide (FAD), riboflavin 5'-phosphate (FMN), and riboflavin. Next, a spectrophotometric assay was developed to measure the conversion of pro-2-PAM to 2-PAM in the presence of riboflavin. KEY FINDINGS In guinea pig brain homogenate, diphenyleneiodonium (DPI), a specific NADPH oxidase inhibitor, reduced pro-2-PAM to 2-PAM conversion to less than 25%. In contrast, riboflavin, FAD, and FMN rapidly oxidized all pro-2-PAM to 2-PAM in an in vitro assay. Riboflavin oxidized pro-2-PAM reactivated diisopropylfluorophosphate (DFP) inhibited AChE. SIGNIFICANCE The present study shows that pro-2-PAM was rapidly oxidized by riboflavin to 2-PAM, which reactivated organophosphate (OP)-inhibited AChE.
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Affiliation(s)
- Farhat A Khan
- Department of Regulated Laboratories, Division of Regulated Activities, Silver Spring, MD 20910, United States.
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Arslan BK, Edmondson DE. Expression of zebrafish (Danio rerio) monoamine oxidase (MAO) in Pichia pastoris: purification and comparison with human MAO A and MAO B. Protein Expr Purif 2010; 70:290-7. [PMID: 20079438 DOI: 10.1016/j.pep.2010.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 12/02/2009] [Accepted: 01/04/2010] [Indexed: 10/20/2022]
Abstract
The expression, purification and characterization of zebrafish monoamine oxidase (zMAO) using the methylotropic yeast Pichia pastoris expression system is described. A 1L fermentation culture of Pichia pastoris containing the gene encoding zMAO under control of the methanol oxidase promotor expresses approximately 200mg of zMAO exhibiting 300 U of total activity. The enzyme is found in the mitochondrial fraction of the expression host and is purified in a 30% yield as a homogenous species with a M(r) of approximately 60,000 on SDS-PAGE and a mass of 58,525+/-40 Da from MALDI-TOF measurements. The zMAO preparation contains one mole of covalent flavin cofactor per mole of enzyme and exhibits >80% functionality. The covalent flavin exhibits fluorescence and EPR spectral properties consistent with known properties of 8 alpha-S-cysteinyl FAD. Chemical degradation of the flavin peptide results in the liberation of FAD. zMAO exhibits no immuno-chemical cross-reactivity with polyclonal anti-sera raised against human MAO A. The enzyme preparation exhibits reasonable thermostability up to a temperature of 30 degrees C. Benzylamine is oxidized with a k(cat) value of 4.7+/-0.1 min(-1) (K(m)=82+/-9 microM) and the enzyme oxidizes phenylethylamine with a k(cat) value of 204 min(-1) (K(m)=86+/-13 microM). The K(m) (O(2)) values determined for zMAO using either benzylamine or phenylethylamine as substrates ranges from 108(+/-5) to 140(+/-21)microM. The functional behavior of this teleost MAO relative to human MAO A and MAO B is discussed.
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Affiliation(s)
- Betül Kacar Arslan
- Department of Biochemistry, Emory University, Rollins Research Bldg., 1510 Clifton Road, Atlanta, GA 30322, USA
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Winkler A, Kutchan TM, Macheroux P. 6-S-cysteinylation of bi-covalently attached FAD in berberine bridge enzyme tunes the redox potential for optimal activity. J Biol Chem 2007; 282:24437-43. [PMID: 17573342 DOI: 10.1074/jbc.m703642200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A mutagenic analysis of the amino acid residues His-104 and Cys-166, which are involved in the bi-covalent attachment of FAD to berberine bridge enzyme, was performed. Here we present a detailed biochemical characterization of the cysteine link to FAD observed in this recently discovered group of flavoproteins. The C166A mutant protein still has residual activity, but reduced to approximately 6% of the turnover rate observed for wild-type berberine bridge enzyme. A more detailed analysis of single reaction steps by stopped-flow spectrophotometry showed that the reductive half-reaction is greatly influenced by the lack of the 6-S-cysteinyl linkage, resulting in a 370-fold decrease in the rate of flavin reduction. Determination of the redox potentials for both wild type and the C166A mutein revealed that the difference in the redox potential observed can fully account for the change in the kinetic properties. The wild-type protein exhibits a midpoint potential of +132 mV, which is the highest redox potential determined for any flavoenzyme so far. Removal of the cysteine linkage to FAD in the C166A mutein leads to a redox potential of +53 mV, which is in the expected range for flavoproteins with a single covalent attachment of FAD to a His residue via its 8-alpha position. We also show that the biochemical properties of the mutein resemble that of typical flavoprotein oxidases and that deviations from this behavior observed for the wild type are due to the FAD-6-S-cysteinyl bond. In addition, rapid reaction stopped-flow experiments give no indication for a radical mechanism supporting the direct transfer of a hydride from the substrate to the cofactor.
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Affiliation(s)
- Andreas Winkler
- Institute of Biochemistry, Graz University of Technology, A-8010 Graz, Austria
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Wu T, Yankovskaya V, McIntire WS. Cloning, sequencing, and heterologous expression of the murine peroxisomal flavoprotein, N1-acetylated polyamine oxidase. J Biol Chem 2003; 278:20514-25. [PMID: 12660232 DOI: 10.1074/jbc.m302149200] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The aminoacyl sequences of three regions of pure bovine N1-acetylated polyamine oxidase (PAO) were obtained and used to search GenBankTM. This led to the cloning and sequencing of a complete coding cDNA for murine PAO (mPAO) and the 5'-truncated coding region of the bovine pao (bpao) gene. A search of GenBankTM indicated that mpao maps to murine chromosome 7 as seven exons. The translated amino acid sequences of mpao and bpao have a -Pro-Arg-Leu peroxisomal targeting signal at the extreme C termini. A beta-alpha-beta FAD-binding motif is present in the N-terminal portion of mPAO. This and several other regions of mPAO and bPAO are highly similar to corresponding sections of other flavoprotein amine oxidases, although the overall identity of aligned sequences indicates that PAO represents a new subfamily of flavoproteins. A fragment of mpao was used as a probe to establish the relative transcription levels of this gene in various mature murine tissues and murine embryonic and breast tissues at different developmental stages. An Escherichia coli expression system has been developed for manufacturing mPAO at a reasonable level. The mPAO so produced was purified to homogeneity and characterized. It was demonstrated definitively that PAO oxidizes N1-acetylspermine to spermidine and 3-acetamidopropanal and that it also oxidizes N1-acetylspermidine to putrescine and 3-acetamidopropanal. Thus, this is the classical polyamine oxidase (EC 1.5.3.11) that is defined as the enzyme that oxidizes these N1-acetylated polyamines on the exo-side of their N4-amino groups. This enzyme is distinguishable from the plant polyamine oxidase that oxidizes spermine on the endo-side of the N4-nitrogen. It differs also from mammalian spermine oxidase that oxidizes spermine (but not N1-acetylspermine or N1-acetylspermidine) at the exo-carbon of its N4-amino group. This report provides details of the biochemical, spectral, oxidation-reduction, and steady-state kinetic properties of pure mPAO.
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Affiliation(s)
- Tianyun Wu
- Molecular Biology Division of the Department of Veterans Affairs Medical Center, San Francisco, the Northern California Institute for Research and Education, San Francisco, California 94121, USA
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van den Heuvel RHH, Fraaije MW, van Berkel WJH. Redox properties of vanillyl-alcohol oxidase. Methods Enzymol 2002; 353:177-86. [PMID: 12078493 DOI: 10.1016/s0076-6879(02)53047-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Edmondson DE, Newton-Vinson P. The covalent FAD of monoamine oxidase: structural and functional role and mechanism of the flavinylation reaction. Antioxid Redox Signal 2001; 3:789-806. [PMID: 11761328 DOI: 10.1089/15230860152664984] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The family of flavoenzymes in which the flavin coenzyme redox cofactor is covalently attached to the protein through an amino acid side chain is covered in this review. Flavin-protein covalent linkages have been shown to exist through each of five known linkages: (a) 8alpha-N(3)-histidyl, (b) 8alpha-N(1)-histidyl, (c) 8alpha-S-cysteinyl, (d) 8alpha-O-tyrosyl, or (e) 6-S-cysteinyl with the flavin existing at either the flavin mononucleotide or flavin adenine dinucleotide (FAD) levels. This class of enzymes is widely distributed in diverse biological systems and catalyzes a variety of enzymatic reactions. Current knowledge on the mechanism of covalent flavin attachment is discussed based on studies on the 8alpha-S-cysteinylFAD of monoamine oxidases A and B, as well as studies on other flavoenzymes. The evidence supports an autocatalytic quinone-methide mechanism of protein flavinylation. Proposals to explain the structural and mechanistic advantages of a covalent flavin linkage in flavoenzymes are presented. It is concluded that multiple factors are involved and include: (a) stabilization of the apoenzyme structure, (b) steric alignment of the cofactor in the active site to facilitate catalysis, and (c) modulation of the redox potential of the covalent flavin through electronic effects of 8alpha-substitution.
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Affiliation(s)
- D E Edmondson
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.
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Motteran L, Pilone MS, Molla G, Ghisla S, Pollegioni L. Cholesterol oxidase from Brevibacterium sterolicum. The relationship between covalent flavinylation and redox properties. J Biol Chem 2001; 276:18024-30. [PMID: 11359791 DOI: 10.1074/jbc.m010953200] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Brevibacterium sterolicum possesses two forms of cholesterol oxidase, one containing noncovalently bound FAD, the second containing a FAD covalently linked to His(69) of the protein backbone. The functional role of the histidyl-FAD bond in the latter cholesterol oxidase was addressed by studying the properties of the H69A mutant in which the FAD is bound tightly, but not covalently, and by comparison with native enzyme. The mutant retains catalytic activity, but with a turnover rate decreased 35-fold; the isomerization step of the intermediate 3-ketosteroid to the final product is also preserved. Stabilization of the flavin semiquinone and binding of sulfite are markedly decreased, this correlates with a lower midpoint redox potential (-204 mV compared with -101 mV for wild-type). Reconstitution with 8-chloro-FAD led to a holoenzyme form of H69A cholesterol oxidase with a midpoint redox potential of -160 mV. In this enzyme form, flavin semiquinone is newly stabilized, and a 3.5-fold activity increase is observed, this mimicking the thermodynamic effects induced by the covalent flavin linkage. It is concluded that the flavin 8alpha-linkage to a (N1)histidine is a pivotal factor in the modulation of the redox properties of this cholesterol oxidase to increase its oxidative power.
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Affiliation(s)
- L Motteran
- Department of Structural Biology, University of Insubria, via J.H. Dunant 3, 21100 Varese, Italy
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Fraaije MW, van den Heuvel RH, van Berkel WJ, Mattevi A. Covalent flavinylation is essential for efficient redox catalysis in vanillyl-alcohol oxidase. J Biol Chem 1999; 274:35514-20. [PMID: 10585424 DOI: 10.1074/jbc.274.50.35514] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
By mutating the target residue of covalent flavinylation in vanillyl-alcohol oxidase, the functional role of the histidyl-FAD bond was studied. Three His(422) mutants (H422A, H422T, and H422C) were purified, which all contained tightly but noncovalently bound FAD. Steady state kinetics revealed that the mutants have retained enzyme activity, although the turnover rates have decreased by 1 order of magnitude. Stopped-flow analysis showed that the H422A mutant is still able to form a stable binary complex of reduced enzyme and a quinone methide product intermediate, a crucial step during vanillyl-alcohol oxidase-mediated catalysis. The only significant change in the catalytic cycle of the H422A mutant is a marked decrease in reduction rate. Redox potentials of both wild type and H422A vanillyl-alcohol oxidase have been determined. During reduction of H422A, a large portion of the neutral flavin semiquinone is observed. Using suitable reference dyes, the redox potentials for the two one-electron couples have been determined: -17 and -113 mV. Reduction of wild type enzyme did not result in any formation of flavin semiquinone and revealed a remarkably high redox potential of +55 mV. The marked decrease in redox potential caused by the missing covalent histidyl-FAD bond is reflected in the reduced rate of substrate-mediated flavin reduction limiting the turnover rate. Elucidation of the crystal structure of the H422A mutant established that deletion of the histidyl-FAD bond did not result in any significant structural changes. These results clearly indicate that covalent interaction of the isoalloxazine ring with the protein moiety can markedly increase the redox potential of the flavin cofactor, thereby facilitating redox catalysis. Thus, formation of a histidyl-FAD bond in specific flavoenzymes might have evolved as a way to contribute to the enhancement of their oxidative power.
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Affiliation(s)
- M W Fraaije
- Department of Genetics, University of Pavia, via Abbiategrasso 207, 27100 Pavia, Italy.
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Notheis C, Drewke C, Leistner E. Purification and characterization of the pyridoxol-5'-phosphate:oxygen oxidoreductase (deaminating) from Escherichia coli. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1247:265-71. [PMID: 7696318 DOI: 10.1016/0167-4838(94)00235-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The E. coli gene pdxH encoding pyridoxol-5'-phosphate:oxygen oxidoreductase (deaminating) (EC 1.4.3.5, PdxH) was cloned, located to phage 20B5 of the library of Kohara et al. (Kohara, Y, Akiyama, K. and Isono K. (1987) Cell 50, 495-508) and assigned to a stretch between 36.0 and 36.1 min of the E. coli chromosome. The gene was overexpressed as a MBP/PdxH fusion protein. The fusion protein was purified by affinity chromatography on an amylose resin and hydrolyzed in the presence of protease 'factor Xa' resulting in homogeneous PdxH protein after another column chromatography. Both the MBP/PdxH fusion protein and the PdxH protein were characterized. Both enzymes are FMN-dependent enzymes which oxidize pyridoxol phosphate and pyridoxamine phosphate in the presence of oxygen to pyridoxal phosphate. Km values of both proteins were similar ranging from 350 to 400 microM for the two substrates. The enzymes did not accept non-phosphorylated substrates. Kinetic data indicate that the enzyme (MBP/PdxH) is product inhibited (Ki 8 microM) by pyridoxal phosphate as a mixed type inhibitor. As revealed by gel exclusion chromatography a minor fraction of the fusion protein formed a dimer, whereas the bulk amount of protein was a monomer. No indication was found that the PdxH protein forms a dimer. The monomer was shown to be catalytically active.
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Affiliation(s)
- C Notheis
- Institut für Pharmazeutische Biologie, Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
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Chapter 7 Progress in succinate:quinone oxidoreductase research. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/s0167-7306(08)60175-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
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Ackrell BA, Cochran B, Cecchini G. Interactions of oxaloacetate with Escherichia coli fumarate reductase. Arch Biochem Biophys 1989; 268:26-34. [PMID: 2643383 DOI: 10.1016/0003-9861(89)90561-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Fumarate reductase of Escherichia coli is converted to a deactivated state when tightly bound by oxaloacetate (OAA). Incubation of the inhibited enzyme with anions or reduction of the enzyme by substrate restores both the activity of the enzyme and its sensitivity to thiol reagents. In these respects the enzyme behaves like cardiac succinate dehydrogenase. Close to an order of magnitude difference was found to exist between the affinities of OAA for the oxidized (KD approximately 0.12 microM) and reduced (KD approximately 0.9 microM) forms of fumarate reductase. Redox titrations of deactivated fumarate reductase preparations have confirmed that reductive activation, as in cardiac succinate dehydrogenase (B. A. C. Ackrell, E. B. Kearney, and D. Edmondson (1975) J. Biol. Chem. 250, 7114-7119), is the result of reduction of the covalently bound FAD moiety and not the non-heme iron clusters of the enzyme. However, the processes differed for the two enzymes; activation of fumarate reductase involved 2e- and 1H+, consistent with reduction of the flavin to the anionic hydroquinone form, whereas the process requires 2e- and 2H+ in cardiac succinate dehydrogenase. The reason for the difference is not known. The redox potential of the FAD/FADH2 couple in FRD (Em approximately -55 mV) was also slightly more positive than that in cardiac succinate dehydrogenase (-90 mV).
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Affiliation(s)
- B A Ackrell
- Molecular Biology Division, Veterans Administration Medical Center, San Francisco, California 94121
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Kitzler JW, Fridovich I. An activity stain for proteins containing noncovalently bound flavin adenine dinucleotide. Anal Biochem 1988; 174:613-7. [PMID: 2467578 DOI: 10.1016/0003-2697(88)90063-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A procedure has been developed to allow the visualization of FAD-containing proteins on polyacrylamide gels. The technique is based on the reconstitution of apo-D-amino acid oxidase with FAD and is thus specific for this cofactor. The stain is sensitive enough to detect 5 pmol of FAD and is therefore useful for the detection of flavoproteins in systems as complex as crude tissue or bacterial extracts.
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Affiliation(s)
- J W Kitzler
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710
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Shokat KM, Leumann CH, Sugasawara R, Schultz PG. Eine über Antikörper gesteuerte Redoxreaktion. Angew Chem Int Ed Engl 1988. [DOI: 10.1002/ange.19881000925] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Shokat KM, Leumann CJ, Sugasawara R, Schultz PG. An Antibody-Mediated Redox Reaction. ACTA ACUST UNITED AC 1988. [DOI: 10.1002/anie.198811721] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Naman SA. ENERGY CONVERSION IN THE DECAY OF TRIPLET LUMIFLAVIN IN THE PRESENCE OF FERRI- AND FERROCYANIDE. Photochem Photobiol 1988. [DOI: 10.1111/j.1751-1097.1988.tb02693.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Claiborne A, Hemmerich P, Massey V, Lawton R. Reaction of 2-thio-FAD-reconstituted p-hydroxybenzoate hydroxylase with hydrogen peroxide. Formation of a covalent flavin-protein linkage. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(20)81909-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Wingard LB. Oxidase-cofactor electrodes aimed at the quantitative measure of substrate concentrations. ACTA ACUST UNITED AC 1982. [DOI: 10.1016/0302-4598(82)80020-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Wingard LB. 514— Oxidase-cofactor electrodes aimed at the quantitative measure of substrate concentrations. J Electroanal Chem (Lausanne) 1982. [DOI: 10.1016/0022-0728(82)85217-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Ikeda T, Ando S, Senda M. Electrochemical Oxidation-Reduction Properties of Covalently Bound FAD of Cholesterol Oxidase Adsorbed on Mercury Electrode Surface. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1981. [DOI: 10.1246/bcsj.54.2189] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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McIntire W, Edmondson DE, Hopper DJ, Singer TP. 8 alpha-(O-Tyrosyl)flavin adenine dinucleotide, the prosthetic group of bacterial p-cresol methylhydroxylase. Biochemistry 1981; 20:3068-75. [PMID: 7248267 DOI: 10.1021/bi00514a013] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
8 alpha-(O-Tyrosyl)riboflavin has been synthesized by condensation of the copper complex of L-tyrosine with 8 alpha-bromotetraacetylriboflavin. The structure of this synthetic product was proven by absorption and 1H NMR spectroscopy and by chemical degradation, which yielded 1 mol of tyrosine per mol of flavin. The synthetic compound comigrated wtih the (aminoacyl)riboflavin isolated from the p-cresol methylhydroxylase of Pseudomonas putida, and both showed identical absorption and fluorescence spectral properties. 8 alpha-(O-Tyrosyl)riboflavin as well as the flavin-containing decapeptide from p-cresol methylhydroxylase undergoes reductive cleavage to form riboflavin and FAD, respectively, on anaerobic treatment with dithionite. In contrast, the native enzyme, on reduction with dithionite, yields a reduced flavin via a red (anionic) flavosemiquinone intermediate, which remains covalently bound to the protein even under denaturing conditions. 8 alpha-(O-Tyrosyl)riboflavin bound to apoflavodoxin is also not cleaved on reduction with dithionite, but, instead, a blue (neutral) semiquinone of tyrosylriboflavin is generated, which is resistant to further reduction with dithionite. Three p-cresol methylhydroxylases, isolated from different strains of Pseudomonas putida, differing in molecular weight and Km values for substrates, contain the same peptide at the flavin site. These data provide definitive proof for the existence of 8 alpha-(O-tyrosyl)riboflavin in nature.
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Singer TP, Edmondson DE. Structure, properties, and determination of covalently bound flavins. Methods Enzymol 1980; 66:253-64. [PMID: 7374473 DOI: 10.1016/0076-6879(80)66466-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Merrill AH, McCormick DB. Flavin affinity chromatography: general methods for purification of proteins that bind riboflavin. Anal Biochem 1978; 89:87-102. [PMID: 212963 DOI: 10.1016/0003-2697(78)90729-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Minamiura N, Yasunobu KT. Purification and some properties of porcine brain mitochondrial monoamine oxidase B. Biochem Pharmacol 1978; 27:2737-43. [PMID: 103556 DOI: 10.1016/0006-2952(78)90050-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Kenney WC, McIntire W, Yamanaka T. Structure of the covalently bound flavin of Chlorobium cytochrome. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 483:467-74. [PMID: 196652 DOI: 10.1016/0005-2744(77)90074-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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McCormick DB. Interactions of flavins with amino acid residues: assessments from spectral and photochemical studies. Photochem Photobiol 1977; 26:169-82. [PMID: 333478 DOI: 10.1111/j.1751-1097.1977.tb07471.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Evidence for a thioether linkage between the flavin and polypeptide chain of Chromatium cytochrome c 552. J Biol Chem 1977. [DOI: 10.1016/s0021-9258(17)40121-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Edmondson DE, Rizzuto F, Tollin G. The effect of 8alpha-substitution on flavin triplet state and semiquinone properties as investigated by flash photolysis. Photochem Photobiol 1977; 25:445-50. [PMID: 896961 DOI: 10.1111/j.1751-1097.1977.tb09169.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Abramovitz AS, Massey V. Interaction of phenols with old yellow enzyme. Physical evidence for charge-transfer complexes. J Biol Chem 1976. [DOI: 10.1016/s0021-9258(17)33165-4] [Citation(s) in RCA: 73] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Hemmerich P. The present status of flavin and flavocoenzyme chemistry. FORTSCHRITTE DER CHEMIE ORGANISCHER NATURSTOFFE = PROGRESS IN THE CHEMISTRY OF ORGANIC NATURAL PRODUCTS. PROGRES DANS LA CHIMIE DES SUBSTANCES ORGANIQUES NATURELLES 1976; 33:451-527. [PMID: 11156 DOI: 10.1007/978-3-7091-3262-3_5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Shiga K, Tollin G, Falk MC, McCormick DB. Binding and oxidation-reduction of monoamine oxidase-type 8alpha-(S-peptidyl) flavins with Azotobacter (Shethna) flavodoxin. Biochem Biophys Res Commun 1975; 66:227-34. [PMID: 809042 DOI: 10.1016/s0006-291x(75)80318-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Ackrell BA, Kearney EB, Edmondson D. Mechanism of the reductive activation of succinate dehydrogenase. J Biol Chem 1975. [DOI: 10.1016/s0021-9258(19)40916-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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