Mechanism of aromatic ring cleavage of a. beta. -biphenylyl ether dimer catalyzed by lignin peroxidase of Phanerochaete chrysosporium

Journal Article · Tue Jun 28 04:00:00 EDT 1988 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00413a031· OSTI ID:6769179

Miki, K; Kondo, R; Renganathan, V; Mayfield, M B; Gold, M H

Homogeneous lignin peroxidase (LiP) oxidized 1-(4-methoxyphenyl)-2-)2,6-dimethoxy-4-phenylphenoxy)-1,3-propanediol (I) to yield 1-(4-methoxyphenyl)-1,2,3-propanetriol (II), ..cap alpha..-(4-methoxy-phenyl)-2-oxo-1,3-dioxolane-4-methanol (III), 5-(4-methoxyphenyl)-2-oxo-1,3-dioxolane-4-methanol (IV), 4-oxo-3-phenyl-2-butenoic acid methyl ester (V), 5-hydroxy-4-phenyl-2(5H)-furanone (VI), 4-oxo-3-phenyl-2-pentenedioic acid dimethyl ester (VII), and 5-carbomethoxy-5-hydroxy-4-phenyl-2(5H)-furanone (VIII). Products II-VIII are all derived from the opening of the B aromatic ring of the substrate. Oxidation of I in H/sub 2/ /sup 18/O resulted in 87% and 65% incorporation of /sup 18/O into the carbonyl oxygen of III and IV, respectively. Oxidation of I under /sup 18/O/sub 2/ resulted in the incorporation of two atoms of oxygen into the aldehyde (V). Oxidation of I under either /sup 18/O/sub 2/ or H/sub 2//sup 18/O resulted in the incorporation of three atoms of oxygen into the lactol VI. Finally, oxidation of I under either /sup 18/O/sub 2/ or H/sub 2//sup 18/O indicated that four atoms of oxygen were incorporated into the lactol VIII. These results are explained by a mechanism involving the one-electron oxidation of the B ring of the substrate to an aryl cation radical by the H/sub 2/O/sub 2/ oxidized enzyme. In these oxidative pathways, only the formation of the aryl cation radical is enzyme-catalyzed. Subsequent reactions appear to be nonenzymatic, accounting for the variety of ring-opened products formed.

• Research Organization: Oregon Graduate Center, Beaverton (USA)
• DOE Contract Number: FG06-86ER13550
• OSTI ID: 6769179
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 27:13; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AROMATICS
BIOCHEMISTRY
BIOLOGICAL PATHWAYS
CARBOHYDRATES
CHEMICAL REACTIONS
CHEMISTRY
DIMERS
ENZYMES
EVEN-EVEN NUCLEI
FUNGI
HYDROGEN COMPOUNDS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
LIGNIN
MOLECULAR STRUCTURE
NUCLEI
ORGANIC COMPOUNDS
OXIDATION
OXIDOREDUCTASES
OXYGEN 18
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
PEROXIDASES
PHANEROCHAETE
PLANTS
POLYSACCHARIDES
SACCHARIDES
STABLE ISOTOPES
WATER