On the Purification and Properties of Mushroom Tyrosinase*

Nakamura, Toshio; Sho, Sadayuki; Ogura, Yasuyuki

doi:10.1093/oxfordjournals.jbchem.a128331

Cited by 33 publications

(9 citation statements)

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“…The function of this Cu2+ in the overall reaction catalyzed by laccase is, however, not yet understood although its presence is not unique to this copper-containing oxidase. The existence of two forms of Cu2+ has been demonstrated by EPR analysis of ceruloplasmin [ll] and can be seen in published EPR spectra of the laccase from lacquer tree [18].…”

Section: Discussionmentioning

confidence: 99%

The Reversible Removal of one Specific Copper(II) from Fungal Laccase

Malkin

Malmström

Vänngård

1969

European Journal of Biochemistry

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One of the four copper atoms of fungal laccase forms a Cu1+‐chelate with bathocuproine disulfonate at pH 4.0 in 1 M guanidine hydrochloride and in the presence of excess ascorbate. Electron paramagnetic resonance (EPR) analysis of the native and copper‐depleted proteins has shown that one of the two Cu2+ in the protein has been removed under these conditions. The Cu2+ removed has been identified as the Type 2 or “non‐blue” Cu2+. The spectral characteristics of the other Cu2+ present in the molecule (the Type 1 Cu2+) appear unchanged after removal of the second Cu2+. The copper‐depleted protein is almost completely devoid of enzymic activity after removal of the Type 2 Cu2+ but both the activity and original copper content can be restored after incubation of the copper‐depleted protein with Cu2+ and ascorbate under anaerobic conditions. No activity is restored by the addition of Cu2+ alone. The rate of removal of the Type 2 Cu2+ closely parallels the rate of decrease of enzymic activity of the protein during the reaction with the chelating agent. These results show that the Type 2 Cu2+ is an integral part of the laccase molecule and has a functional role in the catalytic reaction.

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Section: Discussionmentioning

confidence: 99%

The Reversible Removal of one Specific Copper(II) from Fungal Laccase

Malkin

Malmström

Vänngård

1969

European Journal of Biochemistry

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“…Fungal pigments are also involved in the formation and stability of spores (Mayer and Harel 1979), in the defence and virulence mechanisms (Soler-Rivas et al 1997, Jacobson 2000. Fungal tyrosinases were firstly characterized from the edible mushroom Agaricus bisporus (Nakamura et al 1966, Robb and Gutteridge 1981, Wichers et al 1996 because of enzymatic browning during development and postharvest storage, which particularly decreases the commercial value of the product (Jolivet et al 1998). Further studies on tyrosinases from other fungi such as Neurospora crassa (Kupper et al 1989), Lentinula edodes (Kanda et al 1996), Aspergillus oryzae (Nakamura et al 2000), and Pycnoporus sanguineus (Halaouli et al 2005a) gave new insights into mushroom-tyrosinase biochemical and molecular characteristics.…”

Section: Introductionmentioning

confidence: 99%

Fungal tyrosinases: new prospects in molecular characteristics, bioengineering and biotechnological applications

Halaouli¹,

Asther²,

Sigoillot³

et al. 2006

J Appl Microbiol

325

189

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Tyrosinases are type‐3 copper proteins involved in the initial step of melanin synthesis. These enzymes catalyse both the o‐hydroxylation of monophenols and the subsequent oxidation of the resulting o‐diphenols into reactive o‐quinones, which evolve spontaneously to produce intermediates, which associate in dark brown pigments. In fungi, tyrosinases are generally associated with the formation and stability of spores, in defence and virulence mechanisms, and in browning and pigmentation. First characterized from the edible mushroom Agaricus bisporus because of undesirable enzymatic browning problems during postharvest storage, tyrosinases were found, more recently, in several other fungi with relevant insights into molecular and genetic characteristics and into reaction mechanisms, highlighting their very promising properties for biotechnological applications. The limit of these applications remains in the fact that native fungal tyrosinases are generally intracellular and produced in low quantity. This review compiles the recent data on biochemical and molecular properties of fungal tyrosinases, underlining their importance in the biotechnological use of these enzymes. Next, their most promising applications in food, pharmaceutical and environmental fields are presented and the bioengineering approaches used for the development of tyrosinase‐overproducing fungal strains are discussed.

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“…Tyrosinase (polyphenol oxidase EC 1.14.18.1) is a copper-containing enzyme (Matoba et al, 2006) involved in pigment biosynthesis of various organisms. Mushroom tyrosinase (MT) from Agaricus bisporus due to its accessibility is well characterized and has been used in enzymatic studies (Nakamura et al, 1966;Jolley & Nelson, 1969). It has been proposed that MT consists of two subunits, a heavy (H) and a light (L) with molecular mass of 43 kDa and 13.4 kDa, respectively.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of p-phenylene-bis and phenyl dithiocarbamate sodium salts as inhibitors of mushroom tyrosinase.

Amin

Saboury²,

Mansouri‐Torshizi³

et al. 2010

Acta Biochim Pol

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Two structurally related compounds, phenyl dithiocarbamate sodium salt (I) and p-phenylene-bis (dithiocarbamate) sodium salt (II) were prepared by reaction of the parent aniline and p-phenylenediamine with CS₂ in the presence of sodium hydroxide. These water soluble compounds were characterized by spectroscopic techniques, IR, ¹H NMR and elemental analysis. The inhibitory effects of both compounds on both activities of mushroom tyrosinase (MT) from Agricus bisporus were studied at two temperatures, 27°C and 37°C. L-3, 4-dihydroxyphenylalanine (L-DOPA), and l-tyrosine were used as natural substrates for the catecholase and cresolase enzyme reactions, respectively. Kinetic analysis confirmed noncompetitive inhibition mode of I and mixed type of II on both activities of MT; I and II inhibit MT with inhibition constants (K(I)) of 300 µM and 4 µM, respectively. Analysis of thermodynamic parameters indicated predominant involvement of hydrophobic interactions in binding of I and electrostatic ones in binding of II to MT. It seems that II is a more potent MT inhibitor due to its two charged head groups able to chelate copper ions in the enzyme active site. Intrinsic fluorescence studies as a function of concentrations of both compounds showed unexpectedly quenching of emission intensity without any shift of emission maximum. Extrinsic ANS-fluorescence indicated that only binding of I induces limited changes in the tertiary structure of MT, in agreement with the postulated hydrophobic nature of the binding mechanism.

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On the Purification and Properties of Mushroom Tyrosinase*

Cited by 33 publications

References 0 publications

The Reversible Removal of one Specific Copper(II) from Fungal Laccase

The Reversible Removal of one Specific Copper(II) from Fungal Laccase

Fungal tyrosinases: new prospects in molecular characteristics, bioengineering and biotechnological applications

Evaluation of p-phenylene-bis and phenyl dithiocarbamate sodium salts as inhibitors of mushroom tyrosinase.

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