Manganese (II) oxidation by microperoxidase-11 in hydrophilic organic media

Oyadomari, Masafumi; Kabuto, Mari; Wariishi, Hiroyuki; Tanaka, Hiroo

doi:10.1016/s1369-703x(02)00184-5

Cited by 8 publications

(6 citation statements)

References 18 publications

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“…Solvents with lower E T (30) values such as acetone, acetonitrile, and 1,2-dimethoxyethane, were suggested to have little effect on the conformation of MnP from B. adusta. In the presence of solvents which have higher E T (30) values (such as ethanol, methanol, and diethylene glycol), Mn(II) ions are easily Table 1 Effect of solvents on the effective catalytic values for Mn(II) oxidation by VP of Bjerkandera fumosa In the case of microperoxidase-11 derived from horse heart cytochrome c (MP-11) no correlation between enzyme activity and E T (30) values of the solvents was observed [25]. MP-11 generally exhibited a high catalytic activity in hydrophobic solvents with high E T (30) values (e.g.…”

Section: Resultsmentioning

confidence: 99%

Catalytic activity of versatile peroxidase from Bjerkandera fumosa in aqueous solutions of water–miscible organic solvents

Rodakiewicz-Nowak

Jarosz-Wilkołazka

Luterek

2006

Applied Catalysis A: General

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Section: Resultsmentioning

confidence: 99%

Catalytic activity of versatile peroxidase from Bjerkandera fumosa in aqueous solutions of water–miscible organic solvents

Rodakiewicz-Nowak

Jarosz-Wilkołazka

Luterek

2006

Applied Catalysis A: General

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“…The array of reactions catalysed by MPs is extensive. The oxidation of phenolic substrates, 17,19,20 peroxide decomposition, 21 sulfide oxidation, 22 Mn 2+ oxidation, 23 the nitration of phenol in the presence of NO 2 À , 24 the oxidation of N-methylcarbazole 25 and the dehalogenation of halophenols 26 have all been reported. Thus MPs display activity similar not only to peroxidases, but also to catalase, cytochrome P450, and chloroperoxidase.…”

Section: Introductionmentioning

confidence: 99%

“…The activity of MP-11 was found to be relatively independent of methanol concentration and similar to that observed in aqueous buffer. In a subsequent study investigating the oxidation of Mn 2+ to Mn 3+ , a 50% methanol / water mixture yielded an activity 1.76 times that of 100% aqueous 65 buffer 23 . Methanol concentrations greater than 30% had a detrimental effect on the sulfoxidation of dibenzothiophene, apparently due to competitive inhibition of the peroxidase 28 .…”

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confidence: 99%

The effect of solvent on the catalytic properties of microperoxidase-11

O’Reilly

Magner

2011

Phys. Chem. Chem. Phys.

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The effect of a range of solvents on the catalytic oxidation of methyl phenyl sulfide to methyl phenyl sulfoxide by MP-11 and by a cyclodextrin derivative of MP-11 was examined. The addition of low concentrations of alcohols enhanced the initial rate of sulfoxidation rate, most likely due to dispersion of MP-11 aggregates. Higher alcohol concentrations resulted in a decrease in activity arising from solvation of the hydrophobic sulfide, disrupting binding to the catalyst. In alcohols 10 the yield of product was decreased arising from increased rates of MP-11 deactivation via the formation of aldehydes (for primary alcohols) or by peroxide deactivation. The catalytic activity of cyclodextrin modified MP-11 was similar to that of MP-11 itself, demonstrating that it is the Ntermianal side of MP-11 which is the determinant of catalytic activity. Introduction 15The function of enzymes and proteins in non-aqueous solvents has been well established and, in some cases, commercialised [1][2][3][4][5] . Enzyme catalysis and biosensing in organic solvents offers many advantages over aqueous-based processes including increased substrate/analyte solubility, enhanced thermal stability, more 20 favourable reaction thermodynamics, ease of product / biocatalyst recovery and modified selectivity 1,2,[6][7][8][9][10] . The peroxidases are an important group of enzymes which catalyse a wide variety of synthetically useful oxidation reactions using peroxides as oxidants. In spite of this, their potential in non-aqueous catalytic 25 systems has yet to be realised. This may, in part, be attributed to deactivation of the enzymes by the peroxide oxidant at the concentrations required for such reactions [10][11][12] . Strategies to overcome this problem have been developed, including the slow addition 13 or in-situ generation 14 of the peroxide. Alternatively, 30 studies have shown that a high concentration of substrate relative to the peroxide aids the regeneration of the native enzyme and prevents the formation of the peroxidase intermediates which result in enzyme deactivation [15][16][17] . Microperoxidases (MPs) are the products of the proteolytic 35 digestion of cytochrome c. MP-11 contains residues 11 -21 of the parent protein and is prepared by the action of pepsin on cytochrome c. The haem group is covalently attached to the Cys14 and Cys17 residues via sulfide bonds and is coordinated on the proximal side by the imidazole nitrogen of His18. The 6th axial 40 ligand position is either unoccupied or loosely coordinated by water 18 . In this respect the haem configuration is analogous to that of the peroxidase enzymes and MP-11 displays typical peroxidase activity.The array of reactions catalysed by MPs is extensive. The 45 oxidation of phenolic substrates 17,19,20 , peroxide decomposition 21 , sulfide oxidation 22 , Mn 2+ oxidation 23 , the nitration of phenol in the presence of NO 2 -24 , the oxidation of N-methylcarbazole 25 and the dehalogenation of halophenols 26 have all been reported. Thus MPs display activity similar not on...

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“…MP-11 has been used as a model to simulate the behavior of hemoproteins, such as peroxidase and cytochrome c, etc. because the component and the property of MP-11 is similar to hemoproteins somewhat and its structure is relatively simple [13][14][15][16][17][18][19][20][21][22][23]. The structure simplicity is beneficial for studying and understanding the mechanism of the interaction between MP-11 and the rare earth ion as well as simplifying the theoretical description of different phenomena, such as the structure-function relationship.…”

Section: Introductionmentioning

confidence: 99%