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Gaule TG, Smith MA, Pearson AR, Knowles PF, McPherson MJ. Probing the molecular mechanisms in copper amine oxidases by generating heterodimers. Chembiochem 2015; 16:559-64. [PMID: 25607656 PMCID: PMC4497604 DOI: 10.1002/cbic.201402653] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Indexed: 11/29/2022]
Abstract
For some homodimeric copper amine oxidases (CuAO), there is suggestive evidence of differential activity at the two active sites implying potential cooperativity between the two monomers. To examine this phenomenon for the Arthrobacter globiformis CuAO (AGAO), we purified a heterodimeric form of the enzyme for comparison with the homodimer. The heterodimer comprises an active wild-type monomer and an inactive monomer in which an active-site tyrosine is mutated to phenylalanine (Y382F). This mutation prevents the formation of the trihydroxyphenylalanine quinone (TPQ) cofactor. A pETDuet vector and a dual fusion tag strategy was used to purify heterodimers (WT/Y382F) from homodimers. Purity was confirmed by western blot and native PAGE analyses. Spectral and kinetic studies support the view that whether there are one or two functional monomers in the dimer, the properties of each functional monomer are the same, thus indicating no communication between the active sites in this bacterial enzyme.
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Affiliation(s)
- Thembaninkosi G Gaule
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of LeedsLS2 9JT Leeds (UK) E-mail:
| | - Mark A Smith
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of LeedsLS2 9JT Leeds (UK) E-mail:
| | - Arwen R Pearson
- Hamburg Centre of Ultrafast Imaging, University of Hamburg, CFELBuilding 99, Luruper Chausse 149, 22761 Hamburg (Germany)
| | - Peter F Knowles
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of LeedsLS2 9JT Leeds (UK) E-mail:
| | - Michael J McPherson
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of LeedsLS2 9JT Leeds (UK) E-mail:
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Knowles P, Kurtis C, Murray J, Saysell C, Tambyrajah W, Wilmot C, McPherson M, Phillips S, Dooley D, Brown D, Rogers M, Mure M. Hydrazine and amphetamine binding to amine oxidases: old drugs with new prospects. J Neural Transm (Vienna) 2007; 114:743-6. [PMID: 17406963 DOI: 10.1007/s00702-007-0681-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2006] [Accepted: 11/01/2006] [Indexed: 12/24/2022]
Abstract
Tranylcypromine (TCP), an amphetamine, is a reversible inhibitor of copper-containing amine oxidases. We have solved the structure of the complex of TCP with the amine oxidase from E. coli (ECAO) and shown that only the (+)-enantiomer of TCP binds. Kinetic studies on 2-phenylethylamine and TCP binding to wild-type ECAO and mutational variants fully support the model in which binding of the protonated amine is the first step in the catalytic cycle. Hydrazines are irreversible inhibitors of copper-containing amine oxidases. Binding of hydrazines leads to an adduct ("Adduct 1") with a chromophore at 430 nm which converts at higher pH to another adduct ("Adduct 2") with a chromophore at 520 nm. We have determined the structures of Adduct 1 and 2 for 2-hydrazinopyridine reacted with ECAO. It has been found that Adduct 1 corresponds to the hydrazone and azo tautomers whilst Adduct 2 corresponds to the azo tautomer coordinated to the active site copper. The implications of these results in developing more specific drugs are discussed.
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Affiliation(s)
- P Knowles
- Astbury Centre for Structural Biology, University of Leeds, Leeds, UK.
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Pietrangeli P, Nocera S, Mondovi B, Morpurgo L. Is the catalytic mechanism of bacteria, plant, and mammal copper-TPQ amine oxidases identical? BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1647:152-6. [PMID: 12686125 DOI: 10.1016/s1570-9639(03)00083-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This short review is mostly concerned with the work carried out in Rome on the copper amine oxidase from bovine serum (BSAO). The first target was the copper oxidation state and its relationship with the organic cofactor. It was found that copper is not reduced on reaction with amines under anaerobic conditions or along the catalytic cycle and that it is not within bonding distance of the quinone cofactor. The copper stability in the oxidised state was supported by BSAO ability to oxidise benzylhydrazine, a slow substrate, in the presence of N,N-diethyldithiocarbamate (DDC) and by the substantial catalytic activity of Co(2+)-substituted BSAO. Parallel work established that only one subunit of the dimeric enzyme readily binds reagents of the carbonyl group. Flexible hydrazides with a long aromatic tail were found to be highly specific inhibitors, suggesting the presence of an extended hydrophobic region at the catalytic site. A study by stopped-flow transient spectroscopy and steady state kinetics led to the formulation of a simplified, yet complete and consistent, catalytic mechanism for BSAO that was compared with that available for lentil seedling amine oxidase (LSAO). As in other copper amine oxidases, BSAO is inactivated by H(2)O(2) produced in the catalytic reaction, while the cofactor is stabilised in its reduced state. A conserved tyrosine hydrogen-bonded to the cofactor might be oxidised.
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Affiliation(s)
- P Pietrangeli
- Department of Biochemical Sciences A. Rossi Fanelli and C.N.R. Centre of Molecular Biology, La Sapienza, University, P.le A. Moro 5, 00185 Rome, Italy
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Kishishita S, Okajima T, Kim M, Yamaguchi H, Hirota S, Suzuki S, Kuroda S, Tanizawa K, Mure M. Role of copper ion in bacterial copper amine oxidase: spectroscopic and crystallographic studies of metal-substituted enzymes. J Am Chem Soc 2003; 125:1041-55. [PMID: 12537504 DOI: 10.1021/ja017899k] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The role of the active site Cu(2+) of phenylethylamine oxidase from Arthrobacter globiformis (AGAO) has been studied by substitution with other divalent cations, where we were able to remove >99.5% of Cu(2+) from the active site. The enzymes reconstituted with Co(2+) and Ni(2+) (Co- and Ni-AGAO) exhibited 2.2 and 0.9% activities, respectively, of the original Cu(2+)-enzyme (Cu-AGAO), but their K(m) values for amine substrate and dioxygen were comparable. X-ray crystal structures of the Co- and Ni-AGAO were solved at 2.0-1.8 A resolution. These structures revealed changes in the metal coordination environment when compared to that of Cu-AGAO. However, the hydrogen-bonding network around the active site involving metal-coordinating and noncoordinating water molecules was preserved. Upon anaerobic mixing of the Cu-, Co-, and Ni-AGAO with amine substrate, the 480 nm absorption band characteristic of the oxidized form of the topaquinone cofactor (TPQ(ox)) disappeared rapidly (< 6 ms), yielding the aminoresorcinol form of the reduced cofactor (TPQ(amr)). In contrast to the substrate-reduced Cu-AGAO, the semiquinone radical (TPQ(sq)) was not detected in Co- and Ni-AGAO. Further, in the latter, TPQ(amr) reacted reversibly with the product aldehyde to form a species with a lambda(max) at around 350 nm that was assigned as the neutral form of the product Schiff base (TPQ(pim)). Introduction of dioxygen to the substrate-reduced Co- and Ni-AGAO resulted in the formation of a TPQ-related intermediate absorbing at around 360 nm, which was assigned to the neutral iminoquinone form of the 2e(-)-oxidized cofactor (TPQ(imq)) and which decayed concomitantly with the generation of TPQ(ox). The rate of TPQ(imq) formation and its subsequent decay in Co- and Ni-AGAO was slow when compared to those of the corresponding reactions in Cu-AGAO. The low catalytic activities of the metal-substituted enzymes are due to the impaired efficiencies of the oxidative half-reaction in the catalytic cycle of amine oxidation. On the basis of these results, we propose that the native Cu(2+) ion has essential roles such as catalyzing the electron transfer between TPQ(amr) and dioxygen, in part by providing a binding site for 1e(-)- and 2e(-)-reduced dioxygen species to be efficiently protonated and released and also preventing the back reaction between the product aldehyde and TPQ(amr).
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Affiliation(s)
- Sei'ichiro Kishishita
- Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
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Saysell CG, Tambyrajah WS, Murray JM, Wilmot CM, Phillips SEV, McPherson MJ, Knowles PF. Probing the catalytic mechanism of Escherichia coli amine oxidase using mutational variants and a reversible inhibitor as a substrate analogue. Biochem J 2002; 365:809-16. [PMID: 11985492 PMCID: PMC1222726 DOI: 10.1042/bj20011435] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2001] [Revised: 03/01/2002] [Accepted: 05/02/2002] [Indexed: 11/17/2022]
Abstract
Copper amine oxidases are homodimeric enzymes containing one Cu(2+) ion and one 2,4,5-trihydroxyphenylalanine quinone (TPQ) per monomer. Previous studies with the copper amine oxidase from Escherichia coli (ECAO) have elucidated the structure of the active site and established the importance in catalysis of an active-site base, Asp-383. To explore the early interactions of substrate with enzyme, we have used tranylcypromine (TCP), a fully reversible competitive inhibitor, with wild-type ECAO and with the active-site base variants D383E and D383N. The formation of an adduct, analogous to the substrate Schiff base, between TCP and the TPQ cofactor in the active site of wild-type ECAO and in the D383E and D383N variants has been investigated over the pH range 5.5-9.4. For the wild-type enzyme, the plot of the binding constant for adduct formation (K(b)) against pH is bell-shaped, indicating two pK(a)s of 5.8 and approximately 8, consistent with the preferred reaction partners being the unprotonated active-site base and the protonated TCP. For the D383N variant, the reaction pathway involving unprotonated base and protonated TCP cannot occur, and binding must follow a less favoured pathway with unprotonated TCP as reactant. Surprisingly, for the D383E variant, the K(b) versus pH behaviour is qualitatively similar to that of D383N, supporting a reaction pathway involving unprotonated TCP. The TCP binding data are consistent with substrate binding data for the wild type and the D383E variant using steady-state kinetics. The results provide strong support for a protonated amine being the preferred substrate for the wild-type enzyme, and emphasize the importance of the active-site base, Asp-383, in the primary binding event.
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Affiliation(s)
- Colin G Saysell
- Astbury Centre for Structural Molecular Biology, School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K
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Mills SA, Klinman JP. Evidence Against Reduction of Cu2+to Cu+during Dioxygen Activation in a Copper Amine Oxidase from Yeast. J Am Chem Soc 2000. [DOI: 10.1021/ja000325f] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Saysell CG, Murray JM, Wilmot CM, Brown DE, Dooley DM, Phillips SE, McPherson MJ, Knowles PF. Investigation into the mechanism of λmax shifts and their dependence on pH for the 2-hydrazinopyridine derivatives of two copper amine oxidases. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s1381-1177(99)00068-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Affiliation(s)
- JoAnne Stubbe
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
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Agostinelli E, De Matteis G, Mondovì B, Morpurgo L. Reconstitution of Cu2+-depleted bovine serum amine oxidase with Co2+. Biochem J 1998; 330 ( Pt 1):383-7. [PMID: 9461534 PMCID: PMC1219151 DOI: 10.1042/bj3300383] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Two different Cu2+-depleted derivatives of bovine serum amine oxidase (BSAO) have recently been prepared, which contain about 0.5 mol/dimer of phenylhydrazine-reactive topa quinone (TPQ) cofactor and, depending on the reagents used, about 0.2 or 0.7 residual Cu2+/dimer [Agostinelli, De Matteis, Sinibaldi, Mondovi and Morpurgo (1997) Biochem. J. 324, 497-501]. The benzylamine oxidase activity of both derivatives was <5% and increased up to approximately 20% on incorporation of Co2+, irrespective of the residual Cu2+ content, which was unaffected by the treatment according to atomic absorption and ESR spectroscopy. The residual Cu2+ ions appeared to be distributed one per dimer and to be bound to inactive subunits, whereas Co2+ was bound to active subunits. The change in the active site had an appreciable influence on the kinetic behaviour. With several amines, the kinetic parameters, Km and kc, measured for Co2+-BSAO were different from those for native BSAO. This excludes the possibility that the catalytic activity was due to residual Cu2+. Furthermore, Co2+ restored to nearly native level the intensity of the TPQ 480 nm band and the reactions with phenylhydrazine or benzylhydrazine, which had been slowed down or abolished, respectively, in Cu2+-depleted samples. The CD spectrum, measured for the derivative with low Cu2+ content, was compatible with Co2+ binding to the copper site. The amine oxidase activity of the Co2+ derivative, which cannot form a semiquinone radical as an intermediate of the catalytic reaction, strongly suggests that the Cu+-semiquinone is not an obligatory intermediate of BSAO catalytic pathway.
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Affiliation(s)
- E Agostinelli
- Dipartimento di Scienze Biochimiche 'A. Rossi Fanelli' and Centro di Biologia Molecolare del Consiglio Nazionale delle Ricerche, Università di Roma 'La Sapienza', P.le A. Moro, 5, 00185 Roma, Italy
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11
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Wilmot CM, Murray JM, Alton G, Parsons MR, Convery MA, Blakeley V, Corner AS, Palcic MM, Knowles PF, McPherson MJ, Phillips SE. Catalytic mechanism of the quinoenzyme amine oxidase from Escherichia coli: exploring the reductive half-reaction. Biochemistry 1997; 36:1608-20. [PMID: 9048544 DOI: 10.1021/bi962205j] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The crystal structure of the complex between the copper amine oxidase from Escherichia coli (ECAO) and a covalently bound inhibitor, 2-hydrazinopyridine, has been determined to a resolution of 2.0 A. The inhibitor covalently binds at the 5 position of the quinone ring of the cofactor, 2,4,5-trihydroxyphenylalaninequinone (TPQ). The inhibitor complex is analogous to the substrate Schiff base formed during the reaction with natural monoamine substrate. A proton is abstracted from a methylene group adjacent to the amine group by a catalytic base during the reaction. The inhibitor, however, has a nitrogen at this position, preventing proton abstraction and trapping the enzyme in a covalent complex. The electron density shows this nitrogen is hydrogen bonded to the side chain of Asp383, a totally conserved residue, identifying it as the probable catalytic base. The positioning of Asp383 is such that the pro-S proton of a substrate would be abstracted, consistent with the stereospecificity of the enzyme determined by 1H NMR spectroscopy. Site-directed mutagenesis and in vivo suppression have been used to substitute Asp383 for 12 other residues. The resulting proteins either lack or, in the case of glutamic acid, have very low enzyme activity consistent with an essential catalytic role for Asp383. The O4 position on the quinone ring is involved in a short hydrogen bond with the hydroxyl of conserved residue Tyr369. The distance between the oxygens is less than 2.5 A, consistent with a shared proton, and suggesting ionization at the O4 position of the quinone ring. The Tyr369 residue appears to play an important role in stabilizing the position of the quinone/inhibitor complex. The O2 position on the quinone ring is hydrogen bonded to the apical water ligand of the copper. The basal water ligand, which lies 2.0 A from the copper in the native structure, is at a distance of 3.0 A in the complex. In the native structure, the active site is completely buried, with no obvious route for entry of substrate. In the complex, the tip of the pyridine ring of the bound inhibitor is on the surface of the protein at the edge of the interface between domains 3 and 4, suggesting this as the entry point for the amine substrate.
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Affiliation(s)
- C M Wilmot
- Department of Biochemistry and Molecular Biology, University of Leeds, United Kingdom
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Beinert H. Copper in biological systems. A report from the 7th Manziana Conference, held at Santa Severa, September 11-15, 1995. J Inorg Biochem 1996; 64:79-135. [PMID: 8864234 DOI: 10.1016/0162-0134(96)00083-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In this fifty-seven page report, the author attempts to give the essence of the twenty-four lectures and of an about equal number of posters, including subjects of discussion, that were presented at an international conference on copper proteins held in Italy. The report deals with research carried out up to mid-1995 and contains 140 literature references and thirty-three figures or schemes.
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Affiliation(s)
- H Beinert
- Institute for Enzyme Research, Graduate School, College of Agricultural and Life Sciences, University of Wisconsin--Madison, USA
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Kumar V, Dooley DM, Freeman HC, Guss JM, Harvey I, McGuirl MA, Wilce MC, Zubak VM. Crystal structure of a eukaryotic (pea seedling) copper-containing amine oxidase at 2.2 A resolution. Structure 1996; 4:943-55. [PMID: 8805580 DOI: 10.1016/s0969-2126(96)00101-3] [Citation(s) in RCA: 189] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Copper-containing amine oxidases catalyze the oxidative deamination of primary amines to aldehydes, in a reaction that requires free radicals. These enzymes are important in many biological processes, including cell differentiation and growth, would healing, detoxification and signalling. The catalytic reaction requires a redox cofactor, topa quinone (TPQ), which is derived by post-translational modification of an invariant tyrosine residue. Both the biogenesis of the TPQ cofactor and the reaction catalyzed by the enzyme require the presence of a copper atom at the active site. The crystal structure of a prokaryotic copper amine oxidase from E. coli (ECAO) has recently been reported. RESULTS The first structure of a eukaryotic (pea seedling) amine oxidase (PSAO) has been solved and refined at 2.2 A resolution. The crystallographic phases were derived from a single phosphotungstic acid derivative. The positions of the tungsten atoms in the W12 clusters were obtained by molecular replacement using E. coli amine oxidase as a search model. The methodology avoided bias from the search model, and provides an essentially independent view of a eukaryotic amine oxidase. The PSAO molecule is a homodimer; each subunit has three domains. The active site of each subunit lies near an edge of the beta-sandwich of the largest domain, but is not accessible from the solvent. The essential active-site copper atom is coordinated by three histidine side chains and two water molecules in an approximately square-pyramidal arrangement. All the atoms of the TPQ cofactor are unambiguously defined, the shortest distance to the copper atom being approximately 6 A. CONCLUSIONS There is considerable structural homology between PSAO and ECAO. A combination of evidence from both structures indicates that the TPQ side chain is sufficiently flexible to permit the aromatic grouf to rotate about the Cbeta-Cgamma bond, and to move between bonding and non-bonding positions with respect to the Cu atom. Conformational flexibility is also required at the surface of the molecule to allow the substrates access to the active site, which is inaccessible to solvent, as expected for an enzyme that uses radical chemistry.
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Affiliation(s)
- V Kumar
- School of Chemistry, University of Sydney, NSW 2006, Australia
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De Biase D, Agostinelli E, De Matteis G, Mondovì B, Morpurgo L. Half-of-the-sites reactivity of bovine serum amine oxidase. Reactivity and chemical identity of the second site. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 237:93-9. [PMID: 8620899 DOI: 10.1111/j.1432-1033.1996.0093n.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The organic cofactor of bovine serum amine oxidase was identified as 2,4,5-trihydroxyphenylalanine quinone by means of the phenylhydrazine adduct [Janes, S. M., Mu, D., Wemmer, D., Smith, A. J., Kaur, S., Maltby, D., Burligame, A.L. & Klinman, J.P. (1990) Science 248, 981-987]. A still debated question is, however, whether the dimeric protein binds two mol phenylhydrazine/mole or only one, that is whether it actually contains two identical independent carbonyl cofactors. This matter is addressed in the present study by means of the protein reactions with phenylhydrazine and other inhibitors such as semicarbazide and p-pyridine-2-yl-phenylacetohydrazide. The two latter reagents were found to bind in two steps, one mole/mole dimer in the first step with loss of catalytic activity but only about (0.10-0.35 mol/mol) in the second one. Similar results were obtained by either optical spectroscopy or by reverse-phase HPLC of the labelled peptides produced on proteolysis. Irrespective of the inhibitor nature and reacted amount, all adducts formed on proteolysis a single labelled peptide, of same 25-amino-acid composition, showing that the same cofactor is present in both subunits, in the same stretch of the polypeptide chain. The slow reaction of the second cofactor may be related to slow conformational equilibria, which are established after the first cofactor has reacted and are probably mediated by a change of the hydrogen bond pattern. The conformers spectroscopic properties suggest that they differ in whether the cofactor does or does not directly interact with copper.
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Affiliation(s)
- D De Biase
- Dipartimento di Scienze Biochimiche A. Rossi Fanelli, Università La Sapienza, Roma, Italy
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Lyles GA. Mammalian plasma and tissue-bound semicarbazide-sensitive amine oxidases: biochemical, pharmacological and toxicological aspects. Int J Biochem Cell Biol 1996; 28:259-74. [PMID: 8920635 DOI: 10.1016/1357-2725(95)00130-1] [Citation(s) in RCA: 181] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Mammalian plasma and tissues contain various soluble and membrane-bound enzymes which metabolize the synthetic amine benzylamine particularly well. The sensitivity of these enzymes to inhibition by semicarbazide and related compounds suggests that they contain a cofactor with a reactive carbonyl group, which has been proposed to be either pyridoxal phosphate, pyrroloquinoline quinone or (more recently) 6-hydroxydopa. It is not yet clear if all of these semicarbazide-sensitive amine oxidases (SSAOs) are copper-dependent enzymes. A variety of compounds have now been identified as relatively selective inhibitors to distinguish the SSAOs from other amine oxidases, in order to investigate the properties of SSAOs and their potential role in biogenic and xenobiotic amine metabolism in vivo. While plasma SSAO is soluble, most tissue SSAOs appear to be membrane-bound, probably plasmalemmal enzymes, which may be capable of metabolizing extracellular amines. Vascular (and non-vascular) smooth muscle cells have particularly high SSAO activity, although recently the enzyme has been found in other cell types (e.g. adipocytes, chondrocytes, odontoblasts) implying a functional importance not restricted solely to smooth muscle. The substrate specificity of plasma and tissue SSAOs shows considerable species-related variations. For example, while some endogenously-occurring aromatic amines such as tyramine and tryptamine are metabolized well by SSAO in homogenates of rat blood vessels, and also in vitro inhibition of SSAO can potentiate vasoconstrictor actions of these amines in rat vascular preparations, these amines are poor substrates for human SSAO, thus complicating attempts to generalize possible physiological roles for these enzymes. Vascular SSAO can metabolize the xenobiotic aliphatic amine, allylamine, to the cytotoxic aldehyde acrolein and this has been linked to the ability of allylamine administration to produce cardiovascular lesions in experimental animals, sometimes mimicking features of atherosclerotic disease. Recent studies showing that the endogenously-occurring aliphatic amines methylamine and aminoacetone are metabolized in vitro to formaldehyde and methylglyoxal, respectively, by SSAO in some animal (including human) tissues, suggest the possibility that toxicological consequences upon cellular function could result if such conversions occur in vivo.
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Affiliation(s)
- G A Lyles
- Department of Pharmacology and Clinical Pharmacology, University of Dundee, UK
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16
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Choi YH, Matsuzaki R, Fukui T, Shimizu E, Yorifuji T, Sato H, Ozaki Y, Tanizawa K. Copper/topa quinone-containing histamine oxidase from Arthrobacter globiformis. Molecular cloning and sequencing, overproduction of precursor enzyme, and generation of topa quinone cofactor. J Biol Chem 1995; 270:4712-20. [PMID: 7876243 DOI: 10.1074/jbc.270.9.4712] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The gene coding for histamine oxidase has been cloned and sequenced from a Coryneform bacterium Arthrobacter globiformis. The deduced amino acid sequence consists of 684 residues with a calculated molecular mass of 75,109 daltons and shows a high overall identity (58%) with that of phenethylamine oxidase derived from the same bacterial strain. Although the sequence similarities are rather low when compared with copper amine oxidases from other organisms, the consensus Asn-Tyr-Asp/Glu sequence, in which the middle Tyr is the precursor to the quinone cofactor (the quinone of 2,4,5-trihydroxyphenylalanine, topa) covalently bound to this class of enzymes, is also conserved in the histamine oxidase sequence. To identify the quinone cofactor, an overexpression plasmid has been constructed for the recombinant histamine oxidase. The inactive enzyme purified from the transformed Escherichia coli cells grown in a copper-depleted medium gained maximal activity upon stoichiometric binding of cupric ions. Concomitantly with the enzyme activation by copper, a brownish pink compound was generated in the enzyme, which was identified as the quinone of topa by absorption and resonance Raman spectroscopies of the p-nitrophenylhydrazine-derivatized enzyme and found at the position corresponding to the precursor Tyr (Tyr-402). Therefore, the copper-dependent autoxidation of a specific tyrosyl residue operates on the formation of the topa quinone cofactor in this enzyme, as recently demonstrated with the precursor form of phenethylamine oxidase (Matsuzaki, R., Fukui, T., Sato, H., Ozaki, Y., and Tanizawa, K. (1994) FEBS Lett. 351, 360-364).
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Affiliation(s)
- Y H Choi
- Institute of Scientific and Industrial Research, Osaka University, Japan
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17
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Cai D, Klinman JP. Evidence of a self-catalytic mechanism of 2,4,5-trihydroxyphenylalanine quinone biogenesis in yeast copper amine oxidase. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)31595-3] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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18
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Carter SR, McGuirl MA, Brown DE, Dooley DM. Purification and active-site characterization of equine plasma amine oxidase. J Inorg Biochem 1994; 56:127-41. [PMID: 7798894 DOI: 10.1016/0162-0134(94)85043-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
An improved purification scheme for an amine oxidase from equine plasma (EPAO), a nonruminant source, is described and the protein's active-site is characterized. EPAO is dimeric and contains one Type-2 Cu(II) ion per monomer. The EPAO Cu(II) site is spectroscopically very similar to the Cu(II) sites in other amine oxidases. Unlike the extensively investigated nonruminant amine oxidase from porcine plasma, EPAO does not display half-of-the-sites reactivity; titrations with p-nitrophenylhydrazine and phenylhydrazine indicate two active cofactors per dimer. This cofactor is determined to be the same as that of other copper-containing amine oxidases, 6-hydroxydopa quinone (topa quinone). Upon anaerobic reduction with substrate at ambient temperature, the EPR spectrum of EPAO exhibits a sharp signal at g congruent to 2, attributable to the topa semiquinone. Equine plasma amine oxidase possesses novel in vitro substrate specificity; while other mammalian amine oxidases oxidize norepinephrine only slowly or not at all, EPAO displays significant activity toward this biogenic amine.
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Affiliation(s)
- S R Carter
- Department of Chemistry and Biochemistry, Montana State University, Bozeman 59717-0340
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McGuirl MA, McCahon CD, McKeown KA, Dooley DM. Purification and characterization of pea seedling amine oxidase for crystallization studies. PLANT PHYSIOLOGY 1994; 106:1205-1211. [PMID: 7824646 PMCID: PMC159650 DOI: 10.1104/pp.106.3.1205] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Pea (Pisum sativum L.) seedling amine oxidase (EC 1.4.3.6) is the first amine oxidase to be crystallized that diffracts to atomic resolution (2.5 A). Extensive modifications of a published purification procedure were necessary to obtain protein that would give diffraction-quality crystals. Here we report the improved purification and also use this high-purity protein to reexamine some fundamental characteristics of pea seedling amine oxidase. The extinction coefficient at 280 nm (epsilon 1%(280)) and the molecular mass of the protein are investigated by a variety of techniques, yielding epsilon 1%(280) = 20 cm-1 and a mass 150 +/- 6 kD. In addition, the stoichiometry of the metal and organic cofactors, Cu(II) and 6-hydroxy dopa (Topa) quinone, respectively, is examined. The ratio of Cu(II):Topa:protein monomer is found to be 1:1:1.
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Affiliation(s)
- M A McGuirl
- Department of Chemistry and Biochemistry, Montana State University, Bozeman 59717
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20
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Castellano FN, He Z, Greenaway FT. Hydroxyl radical production in the reactions of copper-containing amine oxidases with substrates. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1157:162-6. [PMID: 8389591 DOI: 10.1016/0304-4165(93)90060-l] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Solutions of porcine kidney diamine oxidase, PKDAO, and bovine plasma amine oxidase, BPAO, were saturated with the spin-trapping agent alpha-phenyl-N-t-butylnitrone, PBN, and incubated with cadaverine or benzylamine substrate, respectively, under aerobic conditions. EPR spectra due to trapped hydroxyl radicals were obtained for both enzymes with no evidence of superoxide formation. Under anaerobic conditions, hydroxyl radicals were formed only when H2O2 was present as well as substrate. Catalase prevented hydroxyl radical formation by PKDAO but not BPAO. The results indicate that hydroxyl radical is produced in the reaction of the product H2O2 with the reduced enzymes and therefore may be important in turnover-related enzyme degradation, but is not a true reaction intermediate.
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Affiliation(s)
- F N Castellano
- Gustaf H. Carlson School of Chemistry, Clark University, Worcester, MA 0610-1477
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21
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Cooper RA, Knowles PF, Brown DE, McGuirl MA, Dooley DM. Evidence for copper and 3,4,6-trihydroxyphenylalanine quinone cofactors in an amine oxidase from the gram-negative bacterium Escherichia coli K-12. Biochem J 1992; 288 ( Pt 2):337-40. [PMID: 1334402 PMCID: PMC1132015 DOI: 10.1042/bj2880337] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The cofactors present in a amine oxidase induced in Escherichia coli K-12 by growth on 2-phenylethylamine have been studied by spectroscopic methods. E.s.r. spectroscopy establishes the presence of cupric copper while resonance Raman spectroscopy on the phenylhydrazine derivative of the enzyme provides strong evidence for the oxidized form of 3,4,6-trihydroxyphenylalanine (TOPA) quinone. The amine oxidase should accordingly be classified as EC 1.4.3.6. This is the first report of such an amine oxidase in a Gram-negative bacterium.
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Affiliation(s)
- R A Cooper
- Bichemistry Department, University of Leicester, U.K
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22
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Buffoni F, Cambi S, Moneti G. Pyrroloquinoline quinone, a method for its isolation and identification by mass spectrometry. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1116:297-304. [PMID: 1319209 DOI: 10.1016/0304-4165(92)90043-t] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Procedures for the unambiguous detection and for the isolation and mass spectrometric identification of pyrroloquinoline quinone (PQQ) are presented. The procedure involved acid hydrolysis of protein in the presence of phenylhydrazine and successive isolation and identification of the formed adduct using mass spectrometry. In HPLC the phenylhydrazone of PQQ gave many methylated products, of which the predominant compound was the pentamethylated derivative. After reaction of the phenylhydrazone derivative of PQQ (PHPQQ) with ammonia, a product was obtained which did not contain phenylhydrazine and which formed a pentamethylated derivative as the main methylation product. The HPLC profiles of the methylated products of PHPQQ and of its ammonia derivative were very characteristic and could be used for identification in addition to mass spectrometry. However, prolonged treatment of proteins with phenylhydrazine during hydrolysis can result in the formation of a material that resembles PQQ in some aspects of its behaviour. Thus, analysis by MS is essential for unambiguous identification. This analytical procedure was applied to pig plasma benzylamine oxidase, pig aorta lysyl oxidase, pig kidney diamine oxidase and bovine serum albumin with negative results. However, samples of pronase contained variable quantities of non-covalently bound PQQ: this can lead to erroneous identification of PQQ in enzyme after pronase digestion.
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Affiliation(s)
- F Buffoni
- Department of Pharmacology, University of Florence, Italy
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Beinert H. Copper in biological systems. A report from the 6th Manziana Conference, September 23-27, 1990. J Inorg Biochem 1991; 44:173-218. [PMID: 1757786 DOI: 10.1016/0162-0134(91)80054-l] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Enzymes and proteins: AO, amine oxidase; and as proposed in reference 3, BSAO, bovine serum AO; SSAO, swine serum AO; SKDAO, swine kidney AO; PSAO, pea seedling AO; APAO, arthrobacter P1AO; MADH, methylamine dehydrogenase; AAO, ascorbic acid oxidase; alpha-AE, alpha-amidating enzyme; Az, azurin; COX, cytochrome c oxidase; CP, ceruloplasmin; DBH, dopamine beta-hydroxylase; GO, galactose oxidase; Hc, hemocyanin; MT, metallotheonein; NIR, nitrite reductase; SOD, superoxide dismutase. Cofactors: Dopa, 3,4 dihydroxyphenylalanine; Topa, 3,4,6 trihydroxyphenyl-alanine; PLP, pyridoxal-phosphate; PQQ, pyrroloquinolinequinone. Reagents: DDC, diethyldithiocarbamate; DMG, diaminoguanidine; DMSA, dimercaptosuccinic acid; NTA, nitrilotriacetic acid. Technique-related: XANES, x-ray absorption near edge spectroscopy; EXAFS, extended x-ray absorption fine structure; ENDOR, electron-nuclear double resonance; ESEEM, electron spin echo envelope modulation; CD, circular dichroism; MCD, magnetic circular dichroism; NMRD, nuclear magnetic resonance dispersion; nqi, nuclear quadrupole interaction; DSC, differential scanning calorimetry.
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Affiliation(s)
- H Beinert
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee 53226
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Duine JA. Quinoproteins: enzymes containing the quinonoid cofactor pyrroloquinoline quinone, topaquinone or tryptophan-tryptophan quinone. EUROPEAN JOURNAL OF BIOCHEMISTRY 1991; 200:271-84. [PMID: 1653700 DOI: 10.1111/j.1432-1033.1991.tb16183.x] [Citation(s) in RCA: 168] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The presently best known and largest group of quinoproteins consists of enzymes using the cofactor 2,7,9-tricarboxy-1H-pyrrolo[2,3-f]quinoline- 4,5-dione (PQQ), a compound having a pyrrole ring fused to a quinoline ring with an o-quinone group in it. Representatives of this group are found among the bacterial, NAD(P)-independent, periplasmic dehydrogenases. Despite their high midpoint redox potential, the overall behaviour of quinoprotein dehydrogenases is similar to that of their counterparts, those using a flavin cofactor or a nicotinamide coenzyme. Apart from an exceptional Gram-positive one, the sole organisms where the presence of PQQ has really been established are Gram-negative bacteria. Evidence for the occurrence of covalently bound PQQ is lacking since it has now been shown that several enzymes previously considered to contain this prosthetic group do not in fact do so. Another group of quinoproteins, consisting of amine oxidoreductases, has a protein chain containing one of the following quinonoid aromatic amino acids: 6-hydroxy-phenylalanine-3,4-dione (TPQ) or 4-(2'-tryptophyl)-tryptophan-6,7-dione (TTQ). There is no doubt that these o-quinones play a role as cofactor, in the case of TPQ in prokaryotic as well as eukaryotic amine oxidases. It appears, therefore, that a novel class of amino-acid-derived cofactors is emerging, ranging from the free radical form of tyrosine and tryptophan to those containing a dicarbonyl group (like the already known pyryvoyl group and the o-quinones here described.
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Affiliation(s)
- J A Duine
- Department of Microbiology and Enzymology, Delft University of Technology, The Netherlands
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Klinman JP, Dooley DM, Duine JA, Knowles PF, Mondovi B, Villafranca JJ. Status of the cofactor identity in copper oxidative enzymes. FEBS Lett 1991; 282:1-4. [PMID: 1851106 DOI: 10.1016/0014-5793(91)80431-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Much conflicting data have appeared in the literature regarding the nature of the active site structures responsible for catalysis in three classes of copper enzymes: the copper amine oxidases, dopamine beta-monooxygenase and galactose oxidase. Although pyrroloquinoline quinone has been proposed to be the active site cofactor in each instance, new findings indicate this is not the case. Instead, recently available data indicate a spectrum of strategies for substrate activation, which range from direct metal catalysis (dopamine beta-monooxygenase) to the involvement of protein-derived radicals (galactose oxidase) and protein-derived quinones (copper amine oxidases).
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Affiliation(s)
- J P Klinman
- Department of Chemistry, University of California, Berkeley 94720
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Greenaway FT, O'Gara CY, Marchena JM, Poku JW, Urtiaga JG, Zou Y. EPR studies of spin-labeled bovine plasma amine oxidase: the nature of the substrate-binding site. Arch Biochem Biophys 1991; 285:291-6. [PMID: 1654770 DOI: 10.1016/0003-9861(91)90362-m] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The carbonyl cofactor of bovine plasma amine oxidase (EC 1.4.3.6), recently shown to be 6-hydroxydopa (also known as topa), has been spin labeled to the extent of one label per enzyme dimer molecule, using 4-amino-2,2,6,6-tetramethylpiperidine-N-oxyl (4-amino-TEMPO) and 4-hydrazino-TEMPO followed by reduction with borohydride. By studying the EPR spectra of the labeled enzyme, it has been deduced that there is no magnetic interaction between the copper and the spin label, and that the spin label is at least 1.3 nm distant from the copper(II) ion in the resting enzyme. The bound label is strongly immobilized, is in a sterically constricted environment, and is not accessible to small anions. Removal of the copper does not alter the EPR spectrum of the label. The results are similar to results for porcine plasma amine oxidase, and show that the copper is not close to, and does not directly interact with, the topa-bound substrate.
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Affiliation(s)
- F T Greenaway
- Department of Chemistry, Clark University, Worcester, Massachusetts 01610
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28
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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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Cragg JE, Herbert RB, Kgaphola MM. Pea-seedling diamine oxidase: Applications in synthesis and evidence relating to its mechanism of action. Tetrahedron Lett 1990. [DOI: 10.1016/s0040-4039(00)97204-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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