Lignin peroxidase oxidation of Mn2+ in the presence of veratryl alcohol, malonic or oxalic acid, and oxygen. Biochemistry 1990 Nov 20;29(46):10475-80
Date
11/20/1990Pubmed ID
2176868DOI
10.1021/bi00498a008Scopus ID
2-s2.0-0025202423 (requires institutional sign-in at Scopus site) 120 CitationsAbstract
Veratryl alcohol (3,4-dimethoxybenzyl alcohol) appears to have multiple roles in lignin degradation by Phanerochaete chrysosporium. It is synthesized de novo by the fungus. It apparently induces expression of lignin peroxidase (LiP), and it protects LiP from inactivation by H2O2. In addition, veratryl alcohol has been shown to potentiate LiP oxidation of compounds that are not good LiP substrates. We have now observed the formation of Mn3+ in reaction mixtures containing LiP, Mn2+, veratryl alcohol, malonate buffer, H2O2, and O2. No Mn3+ was formed if veratryl alcohol or H2O2 was omitted. Mn3+ formation also showed an absolute requirement for oxygen, and oxygen consumption was observed in the reactions. This suggests involvement of active oxygen species. In experiments using oxalate (a metabolite of P. chrysosporium) instead of malonate, similar results were obtained. However, in this case, we detected (by ESR spin-trapping) the production of carbon dioxide anion radical (CO2.-) and perhydroxyl radical (.OOH) in reaction mixtures containing LiP, oxalate, veratryl alcohol, H2O2, and O2. Our data indicate the formation of oxalate radical, which decays to CO2 and CO2.-. The latter reacts with O2 to form O2.-, which then oxidizes Mn2+ to Mn3+. No radicals were detected in the absence of veratryl alcohol. These results indicate that LiP can indirectly oxidize Mn2+ and that veratryl alcohol is probably a radical mediator in this system.
Author List
Popp JL, Kalyanaraman B, Kirk TKAuthor
Balaraman Kalyanaraman PhD Professor in the Biophysics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
BasidiomycotaBenzyl Alcohols
Electron Spin Resonance Spectroscopy
Free Radicals
Kinetics
Magnesium
Malonates
Oxalates
Oxalic Acid
Oxidation-Reduction
Oxygen Consumption
Peroxidases
