title: Thiol oxidase ability of copper ion is specifically retained upon chelation by aldose reductase.
abstract: Bovine lens aldose reductase is susceptible to a copper-mediated oxidation, leading to the generation of a disulfide bridge with the concomitant incorporation of two equivalents of the metal and inactivation of the enzyme. The metal complexed by the protein remains redox active, being able to catalyse the oxidation of different physiological thiol compounds. The thiol oxidase activity displayed by the enzymatic form carrying one equivalent of copper ion (Cu1-AR) has been characterized. The efficacy of Cu1-AR in catalysing thiol oxidation is essentially comparable to the free copper in terms of both thiol concentration and pH effect. On the contrary, the two catalysts are differently affected by temperature. The specificity of the AR-bound copper towards thiols is highlighted with Cu1-AR being completely ineffective in promoting the oxidation of both low-density lipoprotein and ascorbic acid.
authors.affiliation: Biochemistry Unit, Department of Biology, University of Pisa, via San Zeno, 51, 56123, Pisa, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Balestri
authors.affiliation: Biochemistry Unit, Department of Biology, University of Pisa, via San Zeno, 51, 56123, Pisa, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Moschini
authors.affiliation: Biochemistry Unit, Department of Biology, University of Pisa, via San Zeno, 51, 56123, Pisa, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Cappiello
authors.affiliation: Biochemistry Unit, Department of Biology, University of Pisa, via San Zeno, 51, 56123, Pisa, Italy.
authors.forename: Umberto
authors.initials: U
authors.lastname: Mura
authors.affiliation: Biochemistry Unit, Department of Biology, University of Pisa, via San Zeno, 51, 56123, Pisa, Italy. antonella.delcorso@unipi.it.
authors.forename: Antonella
authors.initials: A
authors.lastname: Del-Corso
mesh_terms: D000449:Aldehyde Reductase / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D002614:Chelating Agents / Q000737:chemistry / Q000378:metabolism*; D003300:Copper / Q000737:chemistry; D007477:Ions / Q000737:chemistry / Q000378:metabolism; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D050862:Oxidoreductases Acting on Sulfur Group Donors
chemical_list: D000449:Aldehyde Reductase; D002614:Chelating Agents; D003300:Copper; D007477:Ions; D010088:Oxidoreductases; D050862:Oxidoreductases Acting on Sulfur Group Donors
keywords: Aldose reductase; Copper; Oxidative stress; Thiol oxidase