Oxidation of a Tetrameric Nonphenolic Lignin Model Compound by Lignin Peroxidase

Role of surface tryptophan for peroxidase oxidation of nonphenolic lignin

BACKGROUND Despite claims as key enzymes in enzymatic delignification, very scarce information on the reaction rates between the ligninolytic versatile peroxidase (VP) and lignin peroxidase (LiP) and the lignin polymer is available, due to methodological difficulties related to lignin heterogeneity and low solubility. RESULTS Two water-soluble sulfonated lignins (from Picea abies and Eucalypt...

Lignin Peroxidase Compound III

Lignin peroxidase compound III (LiPIII) was prepared via three procedures: (a) ferrous LiP + O2 (LiPIIIa), (b) ferric LiP + 0; (LiPIIIb), and (c) LiP compound II + excess HzOz followed by treatment with catalase (LiPIIIc). LiPIIIa, h, and c each have a Soret maximum at -414 nm and visible hands at 543 and 578 nm. LiPIIIa, b, and c each slowly reverted to native ferric Lip, releasing stoichiomet...

Manganese-Dependent Cleavage of Nonphenolic Lignin Structures by Ceriporiopsis subvermispora in the Absence of Lignin Peroxidase.

Many ligninolytic fungi appear to lack lignin peroxidase (LiP), the enzyme generally thought to cleave the major, recalcitrant, nonphenolic structures in lignin. At least one such fungus, Ceriporiopsis subvermispora, is nevertheless able to degrade these nonphenolic structures. Experiments showed that wood block cultures and defined liquid medium cultures of C. subvermispora rapidly depolymeriz...

Lignin Model Compound Mediators in Oxidation of a Nonphenolic Comparison of Fungal Laccases and Redox

Comparison of fungal laccases and redox mediators in oxidation of a nonphenolic lignin model compound.

Several fungal laccases have been compared for the oxidation of a nonphenolic lignin dimer, 1-(3, 4-dimethoxyphenyl)-2-(2-methoxyphenoxy)propan-1,3-diol (I), and a phenolic lignin model compound, phenol red, in the presence of the redox mediators 1-hydroxybenzotriazole (1-HBT) or violuric acid. The oxidation rates of dimer I by the laccases were in the following order: Trametes villosa laccase ...