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Maji RC, Bhandari A, Singh R, Roy S, Chatterjee SK, Bowles FL, Ghiassi KB, Maji M, Olmstead MM, Patra AK. Copper coordinated ligand thioether-S and NO2(-) oxidation: relevance to the CuM site of hydroxylases. Dalton Trans 2015; 44:17587-99. [PMID: 26390838 DOI: 10.1039/c5dt02184g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In order to gain insight into the coordination site and oxidative activity of the CuM site of hydroxylases such as peptidylglycine α-hydroxylating monooxygenase (PHM), dopamine β-monooxygenase (DβM), and tyramine β-monooxygenase (TβM), we have synthesized, characterized and studied the oxidation chemistry of copper complexes chelated by tridentate N2Sthioether, N2Osulfoxide or N2Osulfone donor sets. The ligands are those of N-2-methylthiophenyl-2'-pyridinecarboxamide (HL1), and the oxidized variants, N-2-methylsulfenatophenyl-2'-pyridinecarboxamide (HL1(SO)), and N-2-methylsulfinatophenyl-2'-pyridinecarboxamide (HL1(SO2)). Our studies afforded the complexes [(L1)Cu(II)(H2O)](ClO4)·H2O (1·H2O), {[(L1(SO))Cu(II)(CH3CN)](ClO4)}n (2), [(L1)Cu(II)(ONO)] (3), [(L1(SO))Cu(II)(ONO)]n (4), [(L1)Cu(II)(NO3)]n (5), [(L1(SO))Cu(II)(NO3)]n (6) and [(L1(SO2))Cu(II)(NO3)] (7). Complexes 1 and 3 were described in a previous publication (Inorg. Chem., 2013, 52, 11084). The X-ray crystal structures revealed either distorted octahedral (in 2, 4-6) or square-pyramidal (in 1, 3) coordination geometry around Cu(II) ions of the complexes. In the presence of H2O2, conversion of 1→2, 3-5→6 and 6→7 occurs quantitatively via oxidation of thioether-S and/or Cu(ii) coordinated NO2(-) ions. Thioether-S oxidation of L1 also occurs when [L1](-) is reacted with [Cu(I)(CH3CN)4](ClO4) in DMF under O2, albeit low in yield (20%). Oxidations of thioether-S and NO2(-) were monitored by UV-Vis spectroscopy. Recovery of the sulfur oxidized ligands from their metal complexes allowed for their characterization by elemental analysis, (1)H NMR, FTIR and mass spectrometry.
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Affiliation(s)
- Ram Chandra Maji
- Department of Chemistry, National Institute of Technology Durgapur, Mahatma Gandhi Avenue, Durgapur 713209, West Bengal, India.
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Kline CD, Mayfield M, Blackburn NJ. HHM motif at the CuH-site of peptidylglycine monooxygenase is a pH-dependent conformational switch. Biochemistry 2013; 52:2586-96. [PMID: 23530865 DOI: 10.1021/bi4002248] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Peptidylglycine monooxygenase is a copper-containing enzyme that catalyzes the amidation of neuropeptides hormones, the first step of which is the conversion of a glycine-extended pro-peptide to its α-hydroxyglcine intermediate. The enzyme contains two mononuclear Cu centers termed CuM (ligated to imidazole nitrogens of H242, H244 and the thioether S of M314) and CuH (ligated to imidazole nitrogens of H107, H108, and H172) with a Cu-Cu separation of 11 Å. During catalysis, the M site binds oxygen and substrate, and the H site donates the second electron required for hydroxylation. The WT enzyme shows maximum catalytic activity at pH 5.8 and undergoes loss of activity at lower pHs due to a protonation event with a pKA of 4.6. Low pH also causes a unique structural transition in which a new S ligand coordinates to copper with an identical pKA, manifest by a large increase in Cu-S intensity in the X- ray absorption spectroscopy. In previous work (Bauman, A. T., Broers, B. A., Kline, C. D., and Blackburn, N. J. (2011) Biochemistry 50, 10819-10828), we tentatively assigned the new Cu-S interaction to binding of M109 to the H-site (part of an HHM conserved motif common to all but one member of the family). Here we follow up on these findings via studies on the catalytic activity, pH-activity profiles, and spectroscopic (electron paramagnetic resonance, XAS, and Fourier transform infrared) properties of a number of H-site variants, including H107A, H108A, H172A, and M109I. Our results establish that M109 is indeed the coordinating ligand and confirm the prediction that the low pH structural transition with associated loss of activity is abrogated when the M109 thioether is absent. The histidine mutants show more complex behavior, but the almost complete lack of activity in all three variants coupled with only minor differences in their spectroscopic properties suggests that unique structural elements at H are critical for functionality. The data suggest a more general utility for the HHM motif as a copper- and pH-dependent conformational switch.
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Affiliation(s)
- Chelsey D Kline
- Institute of Environmental, Health, Oregon Health and Sciences University, Beaverton, Oregon 97006, USA
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Kapoor A, Shandilya M, Kundu S. Structural insight of dopamine β-hydroxylase, a drug target for complex traits, and functional significance of exonic single nucleotide polymorphisms. PLoS One 2011; 6:e26509. [PMID: 22028891 PMCID: PMC3197665 DOI: 10.1371/journal.pone.0026509] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 09/28/2011] [Indexed: 11/29/2022] Open
Abstract
Background Human dopamine β-hydroxylase (DBH) is an important therapeutic target for complex traits. Several single nucleotide polymorphisms (SNPs) have also been identified in DBH with potential adverse physiological effect. However, difficulty in obtaining diffractable crystals and lack of a suitable template for modeling the protein has ensured that neither crystallographic three-dimensional structure nor computational model for the enzyme is available to aid rational drug design, prediction of functional significance of SNPs or analytical protein engineering. Principal Findings Adequate biochemical information regarding human DBH, structural coordinates for peptidylglycine alpha-hydroxylating monooxygenase and computational data from a partial model of rat DBH were used along with logical manual intervention in a novel way to build an in silico model of human DBH. The model provides structural insight into the active site, metal coordination, subunit interface, substrate recognition and inhibitor binding. It reveals that DOMON domain potentially promotes tetramerization, while substrate dopamine and a potential therapeutic inhibitor nepicastat are stabilized in the active site through multiple hydrogen bonding. Functional significance of several exonic SNPs could be described from a structural analysis of the model. The model confirms that SNP resulting in Ala318Ser or Leu317Pro mutation may not influence enzyme activity, while Gly482Arg might actually do so being in the proximity of the active site. Arg549Cys may cause abnormal oligomerization through non-native disulfide bond formation. Other SNPs like Glu181, Glu250, Lys239 and Asp290 could potentially inhibit tetramerization thus affecting function. Conclusions The first three-dimensional model of full-length human DBH protein was obtained in a novel manner with a set of experimental data as guideline for consistency of in silico prediction. Preliminary physicochemical tests validated the model. The model confirms, rationalizes and provides structural basis for several biochemical data and claims testable hypotheses regarding function. It provides a reasonable template for drug design as well.
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Affiliation(s)
- Abhijeet Kapoor
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
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McIntyre NR, Lowe EW, Belof JL, Ivkovic M, Shafer J, Space B, Merkler DJ. Evidence for substrate preorganization in the peptidylglycine α-amidating monooxygenase reaction describing the contribution of ground state structure to hydrogen tunneling. J Am Chem Soc 2010; 132:16393-402. [PMID: 21043511 DOI: 10.1021/ja1019194] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Peptidylglycine α-amidating monooxygenase (PAM) is a bifunctional enzyme which catalyzes the post-translational modification of inactive C-terminal glycine-extended peptide precursors to the corresponding bioactive α-amidated peptide hormone. This conversion involves two sequential reactions both of which are catalyzed by the separate catalytic domains of PAM. The first step, the copper-, ascorbate-, and O(2)-dependent stereospecific hydroxylation at the α-carbon of the C-terminal glycine, is catalyzed by peptidylglycine α-hydroxylating monooxygenase (PHM). The second step, the zinc-dependent dealkylation of the carbinolamide intermediate, is catalyzed by peptidylglycine amidoglycolate lyase. Quantum mechanical tunneling dominates PHM-dependent C(α)-H bond activation. This study probes the substrate structure dependence of this chemistry using a set of N-acylglycine substrates of varying hydrophobicity. Primary deuterium kinetic isotope effects (KIEs), molecular mechanical docking, alchemical free energy perturbation, and equilibrium molecular dynamics were used to study the role played by ground-state substrate structure on PHM catalysis. Our data show that all Ν-acylglycines bind sequentially to PHM in an equilibrium-ordered fashion. The primary deuterium KIE displays a linear decrease with respect to acyl chain length for straight-chain N-acylglycine substrates. Docking orientation of these substrates displayed increased dissociation energy proportional to hydrophobic pocket interaction. The decrease in KIE with hydrophobicity was attributed to a preorganization event which decreased reorganization energy by decreasing the conformational sampling associated with ground state substrate binding. This is the first example of preorganization in the family of noncoupled copper monooxygenases.
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Affiliation(s)
- Neil R McIntyre
- Department of Chemistry, Xavier University of Louisiana, 1 Drexel Drive, New Orleans, Louisiana 70125, United States
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5
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Slama P, Boucher JL, Réglier M. N-Hydroxyguanidines oxidation by a N3S copper-complex mimicking the reactivity of Dopamine β-Hydroxylase. J Inorg Biochem 2009; 103:455-62. [DOI: 10.1016/j.jinorgbio.2008.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 11/22/2008] [Accepted: 12/17/2008] [Indexed: 10/21/2022]
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6
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Unique Spectroscopic Features and Electronic Structures of Copper Proteins: Relation to Reactivity. HIGH RESOLUTION EPR 2009. [DOI: 10.1007/978-0-387-84856-3_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Berry SM, Mayers JR, Zehm NA. Models of noncoupled dinuclear copper centers in azurin. J Biol Inorg Chem 2008; 14:143-9. [DOI: 10.1007/s00775-008-0432-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Accepted: 09/16/2008] [Indexed: 10/21/2022]
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8
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Slama P, Réglier M. Xanthine oxidase-assisted catalysis by dopamine β-hydroxylase: Mechanistic considerations on the role of superoxide anion. CR CHIM 2007. [DOI: 10.1016/j.crci.2007.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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9
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Yamaguchi S, Kumagai A, Nagatomo S, Kitagawa T, Funahashi Y, Ozawa T, Jitsukawa K, Masuda H. Synthesis, Characterization, and Thermal Stability of New Mononuclear Hydrogenperoxocopper(II) Complexes with N3O-Type Tripodal Ligands Bearing Hydrogen-Bonding Interaction Sites. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2005. [DOI: 10.1246/bcsj.78.116] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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10
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Slama P, Boucher JL, Réglier M. Aromatic N-hydroxyguanidines as new reduction cosubstrates for dopamine β-hydroxylase. Biochem Biophys Res Commun 2004; 316:1081-7. [PMID: 15044095 DOI: 10.1016/j.bbrc.2004.02.163] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2004] [Indexed: 11/16/2022]
Abstract
Conversion of neurotransmitter dopamine into norepinephrine is catalyzed by dopamine beta-hydroxylase (DbH). The reaction requires the presence of both molecular oxygen and a reducing cosubstrate, the assumed physiological cosubstrate being ascorbic acid. We have investigated the ability of a new family of molecules, N-aryl-N'-hydroxyguanidines, to serve as cosubstrates for DbH. N-(4-Methoxyphenyl)-N'-hydroxyguanidine proved to be an efficient reducing agent for DbH. The complete N-hydroxyguanidine moiety was required for activity, as any modification of this function resulted in non-cosubstrate compounds. Moreover, analysis of the products formed from N-(4-methoxyphenyl)-N'-hydroxyguanidine showed that the main oxidation product was a nitrosoimine. Modification of the aromatic para-substituent evidenced an influence of its electronic properties on the catalytic activity whereas steric factors seemed less important. In addition, changing the methoxy-substituent from the para- to the ortho-position led to an inactive compound. Our results demonstrate that N-aryl-N'-hydroxyguanidines are new efficient reducing cosubstrates for DbH and prove that specific interactions with the reducing cosubstrate do take place at the active site of the enzyme.
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Affiliation(s)
- Patrick Slama
- Chimie, Biologie et Radicaux libres, UMR-CNRS 6517, Faculté des Sciences et Techniques de Saint-Jérome, case 432, Avenue Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France.
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11
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Evans JP, Ahn K, Klinman JP. Evidence that dioxygen and substrate activation are tightly coupled in dopamine beta-monooxygenase. Implications for the reactive oxygen species. J Biol Chem 2003; 278:49691-8. [PMID: 12966104 DOI: 10.1074/jbc.m300797200] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Oxygen activation occurs at a wide variety of enzyme active sites. Mechanisms previously proposed for the copper monooxygenase, dopamine beta-monooxygenase (DbetaM), involve the accumulation of an activated oxygen intermediate with the properties of a copper-peroxo or copper-oxo species before substrate activation. These are reminiscent of the mechanism of cytochrome P-450, where a heme iron stabilizes the activated O2 species. Herein, we report two experimental probes of the activated oxygen species in DbetaM. First, we have synthesized the substrate analog, beta,beta-difluorophenethylamine, and examined its capacity to induce reoxidation of the prereduced copper sites of DbetaM upon mixing with O2 under rapid freeze-quench conditions. This experiment fails to give rise to an EPR-detectable copper species, in contrast to a substrate with a C-H active bond. This indicates either that the reoxidation of the enzyme-bound copper sites in the presence of O2 is tightly linked to C-H activation or that a diamagnetic species Cu(II)-O2* has been formed. In the context of the open and fully solvent-accessible active site for the homologous peptidylglycine-alpha-hydroxylating monooxygenase and by analogy to cytochrome P-450, the accumulation of a reduced and activated oxygen species in DbetaM before C-H cleavage would be expected to give some uncoupling of oxygen and substrate consumption. We have, therefore, examined the degree to which O2 and substrate consumption are coupled in DbetaM using both end point and initial rate experimental protocols. With substrates that differ by more than three orders of magnitude in rate, we fail to detect any uncoupling of O2 uptake from product formation. We conclude that there is no accumulation of an activated form of O2 before C-H abstraction in the DbetaM and peptidylglycine-alpha-hydroxylating monooxygenase class of copper monooxygenases, presenting a mechanism in which a diamagnetic Cu(II)-superoxo complex, formed initially at very low levels, abstracts a hydrogen atom from substrate to generate Cu(II)-hydroperoxo and substrate-free radical as intermediates. Subsequent participation of the second copper site per subunit completes the reaction cycle, generating hydroxylated product and water.
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Affiliation(s)
- John P Evans
- Department of Chemistry, University of California, Berkeley, California 94720-1460, USA
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12
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Tubbs KJ, Fuller AL, Bennett B, Arif AM, Makowska-Grzyska MM, Berreau LM. Evaluation of the influence of a thioether substituent on the solid state and solution properties of N3S-ligated copper(ii) complexes. Dalton Trans 2003. [DOI: 10.1039/b304846b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Katterle B, Gvozdev RI, Abudu N, Ljones T, Andersson KK. A continuous-wave electron-nuclear double resonance (X-band) study of the Cu2+ sites of particulate methane mono-oxygenase of Methylococcus capsulatus (strain M) in membrane and pure dopamine beta-mono-oxygenase of the adrenal medulla. Biochem J 2002; 363:677-86. [PMID: 11964168 PMCID: PMC1222520 DOI: 10.1042/0264-6021:3630677] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
All methanotrophic bacteria express a membrane-bound (particulate) methane mono-oxygenase (pMMO). In the present study, we have investigated pMMO in membrane fragments from Methylococcus capsulatus (strain M). pMMO contains a typical type-2 Cu(2+) centre with the following EPR parameters: g(z) 2.24, g(x,y) 2.06, A(Cu)(z) 19.0 mT and A(Cu)(x,y) 1.0 mT. Simulation of the Cu(2+) spectrum yielded a best match by using four equivalent nitrogens (A(N)=1.5 mT, 42 MHz). Incubation with ferricyanide neither changed nor increased the amount of EPR-active Cu(2+), in contrast with other reports. The EPR visible copper seems not to be part of any cluster, as judged from the microwave power saturation behaviour. Continuous-wave electron-nuclear double resonance (CW ENDOR; 9.4 GHz, 5-20 K) experiments at g( perpendicular) of the Cu(II) spectrum show a weak coupling to protons with an A(H) of 2.9 MHz that corresponds to a distance of 3.8 A (1 A identical with 0.1 nm), assuming that it is a purely dipolar coupling. Incubation in (2)H(2)O leads to a significant decrease in these (1)H-ENDOR intensities, showing that these protons are exchangeable. This result strongly suggests that the EPR visible copper site of pMMO is accessible to solvent, which was confirmed by the chelation of the Cu(2+) by diethyldithiocarbamic acid. The (1)H and (14)N hyperfine coupling constants confirm a histidine ligation of the EPR visible copper site in pMMO. The hyperfine structure in the ENDOR or EPR spectra of pMMO is not influenced by the inhibitors azide, cyanide or ammonia, indicating that they do not bind to the EPR visible copper. We compared pMMO with the type-2 Cu(2+) enzyme, dopamine beta-mono-oxygenase (DbetaM). For DbetaM, it is assumed that the copper site is solvent-accessible. CW ENDOR shows similar weakly coupled and (2)H(2)O-exchangeable protons (2.9 MHz), as observed in pMMO, as well as the strongly coupled nitrogens (40 MHz) from the co-ordinating N of the histidines in DbetaM. In conclusion, the resting EPR visible Cu in pMMO is not part of a trinuclear cluster, as has been suggested previously.
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Affiliation(s)
- Bettina Katterle
- Department of Biochemistry, University of Oslo, P.O. Box 1041 Blindern, N-0316 Oslo, Norway
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14
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Nicholas KM, Wentworth P, Harwig CW, Wentworth AD, Shafton A, Janda KD. A cofactor approach to copper-dependent catalytic antibodies. Proc Natl Acad Sci U S A 2002; 99:2648-53. [PMID: 11880619 PMCID: PMC122402 DOI: 10.1073/pnas.052001099] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A strategy for the preparation of semisynthetic copper(II)-based catalytic metalloproteins is described in which a metal-binding bis-imidazole cofactor is incorporated into the combining site of the aldolase antibody 38C2. Antibody 38C2 features a large hydrophobic-combining site pocket with a highly nucleophilic lysine residue, Lys(H93), that can be covalently modified. A comparison of several lactone and anhydride reagents shows that the latter are the most effective and general derivatizing agents for the 38C2 Lys residue. A bis-imidazole anhydride (5) was efficiently prepared from N-methyl imidazole. The 38C2-5-Cu conjugate was prepared by either (i) initial derivatization of 38C2 with 5 followed by metallation with CuCl2, or (ii) precoordination of 5 with CuCl2 followed by conjugation with 38C2. The resulting 38C2-5-Cu conjugate was an active catalyst for the hydrolysis of the coordinating picolinate ester 11, following Michaelis-Menten kinetics [kcat(11) = 2.3 min(-1) and Km(11) 2.2 mM] with a rate enhancement [kcat(11)k(uncat)(11)] of 2.1 x 10(5). Comparison of the second-order rate constants of the modified 38C2 and the Cu(II)-bis-imidazolyl complex k(6-CuCl2) gives a rate enhancement of 3.5 x 10(4) in favor of the antibody complex with an effective molarity of 76.7 M, revealing a significant catalytic benefit to the binding of the bis-imidazolyl ligand into 38C2.
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Affiliation(s)
- Kenneth M Nicholas
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, USA.
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Slama P, Jabre F, Tron T, Réglier M. Dopamine beta-hydroxylase inactivation generates a protein-bound quinone derivative. FEBS Lett 2001; 491:55-8. [PMID: 11226418 DOI: 10.1016/s0014-5793(01)02147-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Bovine dopamine beta-hydroxylase (DbH) was inactivated by hydrogen peroxide and ascorbate in the presence of dioxygen. Both inactivated forms of the enzyme were investigated. We could highlight the presence of a quinone derivative bound to the protein, assumed as being dopa-quinone, that is absent from active enzyme. Such results suggest that a tyrosinyl radical transiently forms during catalysis. Moreover we could show that addition of substrate tyramine to H2O2 incubates is responsible for a partial protection of DbH against inactivation.
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Affiliation(s)
- P Slama
- Chimie, Biologie et Radicaux libres, UMR-CNRS 6517, Faculté des Sciences et Techniques de St-Jérome, case 432, Av. Escadrille Normandie-Niémen, 13397 Cedex 20, Marseille, France
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16
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Yuan H, Collins MLP, Antholine WE. Low-Frequency EPR of the Copper in Particulate Methane Monooxygenase from Methylomicrobium albus BG8. J Am Chem Soc 1997. [DOI: 10.1021/ja9701669] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hua Yuan
- Biophysics Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 Department of Biological Sciences and §Center for Great Lakes Studies, The University of WisconsinMilwaukee, Milwaukee, Wisconsin 53201
| | - Mary Lynne Perille Collins
- Biophysics Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 Department of Biological Sciences and §Center for Great Lakes Studies, The University of WisconsinMilwaukee, Milwaukee, Wisconsin 53201
| | - William E. Antholine
- Biophysics Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 Department of Biological Sciences and §Center for Great Lakes Studies, The University of WisconsinMilwaukee, Milwaukee, Wisconsin 53201
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Alilou EH, Amadei E, Giorgi M, Pierrot M, Réglier M. Synthesis and crystal structures of a series of amide copper(II) complexes. ACTA ACUST UNITED AC 1993. [DOI: 10.1039/dt9930000549] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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19
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Amadéi E, Alilou EH, Eydoux F, Pierrot M, Réglier M, Waegell B. Copper monooxygenase models: hydroxylation reactions resulting from dioxygen activation by copper(I) complexes. ACTA ACUST UNITED AC 1992. [DOI: 10.1039/c39920001782] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Blackburn N, Hasnain S, Pettingill T, Strange R. Copper K-extended x-ray absorption fine structure studies of oxidized and reduced dopamine beta-hydroxylase. Confirmation of a sulfur ligand to copper(I) in the reduced enzyme. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)54471-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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21
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Pettingill T, Strange R, Blackburn N. Carbonmonoxy dopamine beta-hydroxylase. Structural characterization by Fourier transform infrared, fluorescence, and x-ray absorption spectroscopy. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(19)47331-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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22
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Feiters MC. X-Ray Absorption Spectroscopic Studies of Metal Coordination in Zinc and Copper Proteins. COMMENT INORG CHEM 1990. [DOI: 10.1080/02603599008035822] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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23
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Blackburn N, Pettingill T, Seagraves K, Shigeta R. Characterization of a carbon monoxide complex of reduced dopamine beta-hydroxylase. Evidence for inequivalence of the Cu(I) centers. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(18)55407-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Townes S, Titone C, Rosenberg RC. Inhibition of dopamine beta-hydroxylase by bidentate chelating agents. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1037:240-7. [PMID: 2306475 DOI: 10.1016/0167-4838(90)90174-e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
1-2H-Phthalazine hydrazone (hydralazine; HYD), 2-1H-pyridinone hydrazone (2-hydrazinopyridine; HP), 2-quinoline-carboxylic acid (QCA), 1-isoquinolinecarboxylic acid (IQCA), 2,2'-bi-1H-imidazole (2,2'-biimidazole; BI), and 1H-imidazole-4-acetic acid (imidazole-4-acetic acid; IAA) directly and reversibly inhibit homogeneous soluble bovine dopamine beta-hydroxylase (3,4-dihydroxyphenethylamine, ascorbate:oxygen oxidoreductase (beta-hydroxylating), EC 1.14.17.1). HYD, QCA and IAA show competitive allosteric inhibition of dopamine beta-hydroxylase with respect to ascorbate (Kis = 5.7(+/- 0.9) microM, 0.14(+/- 0.03) mM, 0.80(+/- 0.20) mM; nH = 1.4(+/- 0.1), 1.8(+/- 0.4), 2.8(+/- 0.6), respectively). HYD and IAA show slope and intercept mixed-type allosteric inhibition of dopamine beta-hydroxylase with respect to tyramine. QCA shows allosteric uncompetitive inhibition of dopamine beta-hydroxylase with respect to tyramine. HP, BI and IQCA all show linear competitive inhibition (Kis = 1.9(+/- 0.3) microM, 21(+/- 6) microM, and 0.9(+/- 0.3) microM, respectively) with respect to ascorbate. HP and BI show linear mixed-type while IQCA shows linear uncompetitive inhibition of dopamine beta-hydroxylase with respect to tyramine. In the presence of HP, HYD or IAA intersecting double-reciprocal plots of the initial velocity as a function of tyramine concentration at differing fixed levels of ascorbate are observed. These findings are consistent with a uni-uni-ping-pong-ter-bi kinetic mechanism for dopamine beta-hydroxylase that involves a ternary enzyme-ascorbate-tyramine-oxygen complex. The results for HYD, QCA and IAA are the first examples of allosteric inhibitor interactions with dopamine beta-hydroxylase.
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Affiliation(s)
- S Townes
- Department of Chemistry, Howard University, Washington, DC 20059
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Farrington GK, Kumar A, Villafranca JJ. Active site labeling of dopamine beta-hydroxylase by two mechanism-based inhibitors: 6-hydroxybenzofuran and phenylhydrazine. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)40155-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Southan C, Kruse LI. Sequence similarity between dopamine beta-hydroxylase and peptide alpha-amidating enzyme: evidence for a conserved catalytic domain. FEBS Lett 1989; 255:116-20. [PMID: 2792366 DOI: 10.1016/0014-5793(89)81072-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A comparison of human dopamine beta-hydroxylase (EC 1.14.17.1) with bovine peptide C-terminal alpha-amidating enzyme (EC 1.14.17.3), revealed a 28% identity extending throughout a common catalytic domain of approximately 270 residues. The shared biochemical properties of these two enzymes from neurosecretory granules suggests that the sequence similarity reflects a genuine homology and provides a structural basis for a new family of copper type II, ascorbate-dependent monooxygenases.
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Affiliation(s)
- C Southan
- Department of Medicinal Chemistry, Smith Kline & French Research Limited, Welwyn, England
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