Manganese peroxidase from the basidiomycete Phanerochaete chrysosporium: spectral characterization of the oxidized states and the catalytic cycle

Journal Article · Tue Jul 12 00:00:00 EDT 1988 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00414a061· OSTI ID:7003029

Wariishi, H; Akileswaran, L; Gold, M H

Manganese peroxidase (MnP), an extracellular heme enzyme from the lignin-degrading fungus Phanerochaete chrysosporium, catalyzes the Mn(II)-dependent oxidation of a variety of phenols. Herein, the authors spectroscopically characterize the oxidized states of MnP compounds I, II, and III and clarify the role of Mn in the catalytic cycle of the enzyme. Addition of 1 equiv of H/sub 2/O/sub 2/ to the native ferric enzyme yields compound I, characterized by absorption maxima at 407, 558, 605, and 650 nm. Addition of 2 or 250 equiv of H/sub 2/O/sub 2/ to the native enzyme yields compound II or III, respectively, identified by absorption maxima at 420, 528, and 555 nm or at 417, 545, and 579 nm, respectively. These characteristics are very similar to those of horseradish peroxidase (HRP) and lignin peroxidase (LiP) compounds I, II, and III. Addition of 1 equiv of either Mn(II), ferrocyanide, or a variety of phenols to MnP compound I rapidly reduces it to MnP compound II. In contrast, only Mn(II) or ferrocyanide, added at a concentration of 1 equiv, reduces compound II. The Mn(III) produced by the enzymic oxidation of Mn(II) oxidizes the terminal phenolic substrates. This indicates that compounds I and II of MnP contain 2 and 1 oxidizing equiv, respectively, over the native ferric resting enzyme and that the catalytic cycle of the enzyme follows the path native enzyme ..-->.. compound I ..-->.. compound II ..-->.. native enzyme. In addition, these results indicate that Mn(II) serves as an obligatory substrate for MnP compound II, allowing the enzyme to complete its catalytic cycle. Finally, the Mn(II)/Mn(III) redox couple enables the enzyme to rapidly oxidize the terminal phenolic substrates.

• Research Organization: Oregon Graduate Center, Beaverton (USA)
• DOE Contract Number: FG06-86ER13550
• OSTI ID: 7003029
• Journal Information: Biochemistry; (United States), Vol. 27:14
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
PEROXIDASES
ABSORPTION SPECTRA
BIOCHEMISTRY
CATALYSIS
MANGANESE COMPOUNDS
OXIDATION
PHANEROCHAETE
PHENOLS
REDUCTION
AROMATICS
CHEMICAL REACTIONS
CHEMISTRY
ENZYMES
FUNGI
HYDROXY COMPOUNDS
ORGANIC COMPOUNDS
OXIDOREDUCTASES
PLANTS
SPECTRA
TRANSITION ELEMENT COMPOUNDS
550200* - Biochemistry