Autoxidation of 4-methylcatechol: a model for the study of the biosynthesis of copper amine oxidases quinonoid cofactor.
The autoxidation of 4-methylcatechol under quasi-physiological conditions, leading to 2-hydroxy-5-methyl-1,4-benzoquinone, was investigated. The effects of pH and metal ions were examined. An electrophilic attack of dioxygen to the 4-methylcatechol monoanion to form a transient peroxo species is proposed. It was concluded that such a non-enzymic conversion is likely for this model compound and for its physiological counterpart, a specific tyrosyl residue incorporated in the protein chain at the active site of copper amine oxidases.
Rinaldi
A C
AC
Dipartimento di Medicina Sperimentale e Scienze Biochimiche, Università di Roma Tor Vergata, Italy.
Porcu
M C
MC
Curreli
N
N
Rescigno
A
A
Finazzi-Agró
A
A
Pedersen
J Z
JZ
Rinaldi
A
A
Sanjust
E
E
D006631:Amine Oxidase (Copper-Containing) / Q000378:metabolism*; D000595:Amino Acid Sequence; D002396:Catechols / Q000737:chemistry*; D002614:Chelating Agents; D003300:Copper; D003497:Cyclic N-Oxides; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives* / Q000096:biosynthesis; D004151:Dipeptides; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008956:Models, Chemical; D008969:Molecular Sequence Data; D009842:Oligopeptides; D010084:Oxidation-Reduction; D010100:Oxygen; D013053:Spectrophotometry; D013113:Spin Labels; D013329:Structure-Activity Relationship
D002396:Catechols; D002614:Chelating Agents; D003497:Cyclic N-Oxides; D004151:Dipeptides; D009842:Oligopeptides; D013113:Spin Labels; C018599:4-methylcatechol; C001388:6-hydroxydopa; D004295:Dihydroxyphenylalanine; D003300:Copper; D006631:Amine Oxidase (Copper-Containing); D010100:Oxygen; C001803:tempol