title: Full, reversible copper removal from ascorbate oxidase.
abstract: Anaerobic treatment with cyanide of reduced ascorbate oxidase causes total depletion of copper. No significant amount of the metal is reincorporated when the apo-enzyme is incubated with cupric ions, but it is upon incubation with a stoichiometric amount (eight mol per mol of native enzyme) of a Cu(I) complex stable in air [Cu(I)(thiourea)3]Cl. The yield in reconstituted protein is higher under anaerobic conditions (85-90%) than in air (70-75%). By treatment with less than stoichiometric amounts of [Cu(I)(thiourea)3]Cl the apo-protein binds copper preferentially at the blue copper site. As a consequence the recovery of enzymatic activity is percentually lower than copper reincorporation.
mesh_terms: D001051:Apoenzymes; D001059:Apoproteins; D001204:Ascorbate Oxidase; D055598:Chemical Phenomena; D002621:Chemistry; D003300:Copper / Q000302:isolation & purification*; D003486:Cyanides; D004578:Electron Spin Resonance Spectroscopy; D009942:Organometallic Compounds; D010088:Oxidoreductases; D010100:Oxygen; D013053:Spectrophotometry; D013890:Thiourea / Q000031:analogs & derivatives
chemical_list: D001051:Apoenzymes; D001059:Apoproteins; D003486:Cyanides; D009942:Organometallic Compounds; C042723:copper(I)-tris(thiourea); D003300:Copper; D010088:Oxidoreductases; D001204:Ascorbate Oxidase; D013890:Thiourea; D010100:Oxygen