title: The regeneration with ascorbate of Helix pomatia methaemocyanin mediated by hydrogen peroxide.
abstract: The regeneration of the copper bands of H. pomatia haemocyanin proceeds much more slowly with an excess of ascorbate than with a slight excess of hydrogen peroxide. The regenerating agent with ascorbate is hydrogen perioxide, formed in its autoxidation at the air. This was concluded after regeneration experiments with ascorbate under strictly anaerobic conditions and at the air in the presence of catalase. The autoxidation of ascorbate was catalysed by Fe and Cu ions. In the presence of EDTA there is still metal catalysis, especially in slightly alkaline medium, due to the Fe(III)-EDTA complex. Addition of diethylenetriamine pentaacetate completely abolished the metal catalysis.
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology*; D003300:Copper; D004492:Edetic Acid; D005290:Ferric Compounds / Q000378:metabolism; D006372:Helix, Snails / Q000378:metabolism; D006433:Hemocyanins / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D007501:Iron; D007700:Kinetics; D010084:Oxidation-Reduction
chemical_list: D005290:Ferric Compounds; C015985:methemocyanin; D003300:Copper; D006433:Hemocyanins; D004492:Edetic Acid; D006861:Hydrogen Peroxide; D007501:Iron; D001205:Ascorbic Acid