Manganese(II) oxidation by manganese peroxidase from the basidiomycete Phanerochaete chrysosporium

Kinetic mechanism and role of chelators

Hiroyuki Wariishi, Khadar Valli, Michael H. Gold

Research output: Contribution to journalArticle

819 Citations (Scopus)

Abstract

Manganese oxidation by manganese peroxidase (MnP) was investigated. Stoichiometnc kinetic and MnII binding studies demonstrated that MnP has a single manganese binding site near the heme and two MnIII equivalents are formed at the expense of one H2O2 equivalent. Since each catalytic cycle step is irreversible, the data fit a peroxidase ping-pong mechanism rather than an ordered bi-bi ping-pong mechanism. MnIII-organic acid complexes oxidize terminal phenolic substrates in a second-order reaction. MnIII-lactate and -tartrate also react slowly with H2O2 with third-order kinetics. The latter slow reaction does not interfere with the rapid MnP oxidation of phenols. Oxalate and malonate are the on y organic acid chelators secreted by the fungus in significant amounts. No relationship between stimulation of enzyme activity and chelator size was found, suggesting that the substrate is free MnII rather than MnII-chelator complex. The enzyme competes with chelators for free MnII. Optimal chelators, such as malonate, facilitate MnIII dissociation from the enzyme, stabilize MnIII in aqueous solution, and have a relatively low MnII binding constant.

Original languageEnglish
Pages (from-to)23688-23695
Number of pages8
JournalJournal of Biological Chemistry
Volume267
Issue number33
Publication statusPublished - Nov 25 1992
Externally publishedYes

Fingerprint

manganese peroxidase
Phanerochaete
Basidiomycota
Chelating Agents
Manganese
Oxidation
Kinetics
Organic acids
Enzymes
Acids
Oxalates
Phenols
Enzyme activity
Substrates
Fungi
Heme
Peroxidase
Lactic Acid
Binding Sites

All Science Journal Classification (ASJC) codes

  • Biochemistry

Cite this

Manganese(II) oxidation by manganese peroxidase from the basidiomycete Phanerochaete chrysosporium : Kinetic mechanism and role of chelators. / Wariishi, Hiroyuki; Valli, Khadar; Gold, Michael H.

In: Journal of Biological Chemistry, Vol. 267, No. 33, 25.11.1992, p. 23688-23695.

Research output: Contribution to journalArticle

@article{56ad7fb47db542e49e8cf05e2880ffa9,
title = "Manganese(II) oxidation by manganese peroxidase from the basidiomycete Phanerochaete chrysosporium: Kinetic mechanism and role of chelators",
abstract = "Manganese oxidation by manganese peroxidase (MnP) was investigated. Stoichiometnc kinetic and MnII binding studies demonstrated that MnP has a single manganese binding site near the heme and two MnIII equivalents are formed at the expense of one H2O2 equivalent. Since each catalytic cycle step is irreversible, the data fit a peroxidase ping-pong mechanism rather than an ordered bi-bi ping-pong mechanism. MnIII-organic acid complexes oxidize terminal phenolic substrates in a second-order reaction. MnIII-lactate and -tartrate also react slowly with H2O2 with third-order kinetics. The latter slow reaction does not interfere with the rapid MnP oxidation of phenols. Oxalate and malonate are the on y organic acid chelators secreted by the fungus in significant amounts. No relationship between stimulation of enzyme activity and chelator size was found, suggesting that the substrate is free MnII rather than MnII-chelator complex. The enzyme competes with chelators for free MnII. Optimal chelators, such as malonate, facilitate MnIII dissociation from the enzyme, stabilize MnIII in aqueous solution, and have a relatively low MnII binding constant.",
author = "Hiroyuki Wariishi and Khadar Valli and Gold, {Michael H.}",
year = "1992",
month = "11",
day = "25",
language = "English",
volume = "267",
pages = "23688--23695",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "33",

}

TY - JOUR

T1 - Manganese(II) oxidation by manganese peroxidase from the basidiomycete Phanerochaete chrysosporium

T2 - Kinetic mechanism and role of chelators

AU - Wariishi, Hiroyuki

AU - Valli, Khadar

AU - Gold, Michael H.

PY - 1992/11/25

Y1 - 1992/11/25

N2 - Manganese oxidation by manganese peroxidase (MnP) was investigated. Stoichiometnc kinetic and MnII binding studies demonstrated that MnP has a single manganese binding site near the heme and two MnIII equivalents are formed at the expense of one H2O2 equivalent. Since each catalytic cycle step is irreversible, the data fit a peroxidase ping-pong mechanism rather than an ordered bi-bi ping-pong mechanism. MnIII-organic acid complexes oxidize terminal phenolic substrates in a second-order reaction. MnIII-lactate and -tartrate also react slowly with H2O2 with third-order kinetics. The latter slow reaction does not interfere with the rapid MnP oxidation of phenols. Oxalate and malonate are the on y organic acid chelators secreted by the fungus in significant amounts. No relationship between stimulation of enzyme activity and chelator size was found, suggesting that the substrate is free MnII rather than MnII-chelator complex. The enzyme competes with chelators for free MnII. Optimal chelators, such as malonate, facilitate MnIII dissociation from the enzyme, stabilize MnIII in aqueous solution, and have a relatively low MnII binding constant.

AB - Manganese oxidation by manganese peroxidase (MnP) was investigated. Stoichiometnc kinetic and MnII binding studies demonstrated that MnP has a single manganese binding site near the heme and two MnIII equivalents are formed at the expense of one H2O2 equivalent. Since each catalytic cycle step is irreversible, the data fit a peroxidase ping-pong mechanism rather than an ordered bi-bi ping-pong mechanism. MnIII-organic acid complexes oxidize terminal phenolic substrates in a second-order reaction. MnIII-lactate and -tartrate also react slowly with H2O2 with third-order kinetics. The latter slow reaction does not interfere with the rapid MnP oxidation of phenols. Oxalate and malonate are the on y organic acid chelators secreted by the fungus in significant amounts. No relationship between stimulation of enzyme activity and chelator size was found, suggesting that the substrate is free MnII rather than MnII-chelator complex. The enzyme competes with chelators for free MnII. Optimal chelators, such as malonate, facilitate MnIII dissociation from the enzyme, stabilize MnIII in aqueous solution, and have a relatively low MnII binding constant.

UR - http://www.scopus.com/inward/record.url?scp=0027096634&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027096634&partnerID=8YFLogxK

M3 - Article

VL - 267

SP - 23688

EP - 23695

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 33

ER -