Stereochemistry and kinetic isotope effects in the bovine plasma amine oxidase catalyzed oxidation of dopamine

Summers, Michael C.; Marković, Radmila; Klinman, Judith P.

doi:10.1021/bi00577a019

Cited by 41 publications

(36 citation statements)

References 20 publications

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“…p=Hydroxybenzylamine is also [9] oxidised in the presence of the plasma enzyme with stereospecific removal of the #-hydrogen. The reason for the nonstereospecifrcity of the oxidation of phenethylamines is under investigation [2]. …”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Stereochemistry of oxidation of benzylamine by the amine oxidase from beef plasma

Battersby¹,

Staunton²,

Klinman³

et al. 1979

FEBS Letters

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Section: Resultsmentioning

confidence: 99%

“…The enzyme was purified to homogeneity by a modification of method in [l] and will be detailed in [2]. The enzyme was stored as a suspension in 0.1 M Na2HP04/KH2P04 (pH 7.0) buffer containing ammonium sulphate to 0.55 saturation.…”

Section: Enzyme and Substratesmentioning

confidence: 99%

Stereochemistry of oxidation of benzylamine by the amine oxidase from beef plasma

Battersby¹,

Staunton²,

Klinman³

et al. 1979

FEBS Letters

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“…All materials were obtained commercially and were reagent grade unless otherwise indicated. Bovine serum amine oxidase was purified by a modification of the procedure of Summers et al (15). The protein concentration was determined spectrophotometrically at 280 nm using an E 1cm 1% of 20.8 (16).…”

Section: Methodsmentioning

confidence: 99%

Probing the Mechanism of Proton Coupled Electron Transfer to Dioxygen: the Oxidative Half-Reaction of Bovine Serum Amine Oxidase

1998

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Bovine serum amine oxidase (BSAO) catalyzes the oxidative deamination of primary amines, concomitant with the reduction of molecular oxygen to hydrogen peroxide via a ping-pong mechanism. A protocol has been developed for an analysis of chemical and kinetic mechanisms in the conversion of dioxygen to hydrogen peroxide. Steady-state kinetics show that two groups need to be deprotonated to facilitate the oxidative half-reaction. The pH dependence of Vmax/Km(O2) reveals pKa's of 6.2 +/- 0.3 and 7.0 +/- 0.2, respectively. A pKa of 7.2 +/- 0.1 has been obtained from a titration of anaerobically reduced BSAO using UV-vis spectrophotometry. The near identity of the pKa obtained from the reduced enzyme titration with the second pKa from steady-state kinetics suggests that this second pKa arises from the reduced cofactor. The assignment of pKa is supported by the observed pH dependence for formation of the cofactor semiquinone signal, detected by EPR spectroscopy under anaerobic conditions. To address the nature of rate-limiting steps in the oxidative half-reaction, the solvent isotope effect, viscosity effect, and O-18 isotope effect on Vmax/Km(O2) have been determined. The solvent isotope effect is indistinguishable from unity, ruling out a proton transfer as a rate-determining step. Use of glucose as a solvent viscosogen shows no viscosity effect, indicating that binding of oxygen is not in the rate-determining step. The O-18 kinetic isotope effect is independent of pH with an average value of 18(V/K) = 1.0097 +/- 0. 0010. This has been compared to calculated equilibrium O-18 isotope effects for various dioxygen intermediate species [Tian and Klinman (1993) J. Am. Chem. Soc. 115, 8891], leading to the conclusion that either the first electron transfer to dioxygen or the desorption of product peroxide from a Cu(II)-OOH complex could be the rate-limiting step. The distribution of steady-state enzyme species was, therefore, analyzed through a combination of stopped-flow experiments and analysis of DV and D(V/K) for benzylamine oxidation. We conclude that the major species accumulating in the steady state are the oxidized cofactor-substrate Schiff base complex and the reduced, aminoquinol form of cofactor. These data rule out a slow release of product hydroperoxide from the aminoquinone form of enzyme, leading to the conclusion that the first electron transfer from substrate-reduced cofactor to dioxygen is the rate-determining step in the oxidative half-reaction. This step is also estimated to be 40% rate-limiting in kcat. An important mechanistic conclusion from this study is that dioxygen binding is a separate step from the rate-limiting electron-transfer step to form superoxide. On the basis of a recently determined X-ray structure for the active form of a yeast amine oxidase from Hansenula polymorpha [Li et al. (1998) Structure 6, 293], a hydrophobic space has been identified near the O-2 position of reduced cofactor as the putative dioxygen binding site. Movement of superoxide from this site onto the Cu(II) at the act...

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“…The different isotopomers of DA tritiated in the 2- and 3-positions were obtained from (dihydroksyphenyl)ethyl alcohols as the result of three step chemical procedures [117]. Also, the very old data reports on chemo-enzymatic preparation of DA labeled with deuterium and tritium in the side chain [118, 119]. Deuterated [( 1S )- 2 H]-DA and [( 1R )- 2 H]-DA were obtained by enzymatic decarboxylation of [2- 2 H]- l -DOPA and l -DOPA, respectively [120].…”

Section: Synthesismentioning

confidence: 99%

The chemo- enzymatic synthesis of labeled l-amino acids and some of their derivatives

Pająk

Pałka

Winnicka

et al. 2018

J Radioanal Nucl Chem

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This review compiles the combined chemical and enzymatic synthesis of aromatic l-amino acids (l-phenylalanine, l-tyrosine, l-DOPA, l-tryptophan, and their derivatives and precursors) specifically labeled with carbon and hydrogen isotopes, which were elaborated in our research group by the past 20 years. These compounds could be then employed to characterize the mechanisms of enzymatic reactions via kinetic and solvent isotope effects methods.

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Stereochemistry and kinetic isotope effects in the bovine plasma amine oxidase catalyzed oxidation of dopamine

Cited by 41 publications

References 20 publications

Stereochemistry of oxidation of benzylamine by the amine oxidase from beef plasma

Stereochemistry of oxidation of benzylamine by the amine oxidase from beef plasma

Probing the Mechanism of Proton Coupled Electron Transfer to Dioxygen: the Oxidative Half-Reaction of Bovine Serum Amine Oxidase

The chemo- enzymatic synthesis of labeled l-amino acids and some of their derivatives

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