title: New reaction system for hydrocarbon oxidation by chloroperoxidase.
abstract: A novel reaction system was developed to maximize the catalytic efficiency of chloroperoxidase (CPO, from Caldariomyces fumago) toward the oxidation of hydrocarbons. The reaction system consisted of an organic/aqueous emulsion comprising pure substrate and aqueous buffer supplemented with the surfactant dioctyl sulfosuccinate. The emulsion system attenuated not only the destabilizing effects of the substrate and product on the enzyme by emulsifying the compounds, but also oxidant toxicity (oxidative stress) by increasing substrate availability. As a result, CPO exhibited total turnover numbers (TTNs, defined as the amount of product produced over the catalytic lifetime of the enzyme) of ca. 20,000 mol product/mol enzyme for the oxidation of styrene, toluene, and o-, m-, p-xylenes. The TTNs are over 10-fold higher than those previously reported for the oxidation of benzylic hydrocarbons by CPO. This study represents a significant step toward the development of CPO as a practical catalyst for large-scale organic syntheses.
authors.affiliation: Department of Chemical Engineering, University of California, Berkeley, 94720, USA.
authors.forename: Jin-Byung
authors.initials: JB
authors.lastname: Park
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Clark
mesh_terms: D001203:Ascomycota / Q000201:enzymology*; D001711:Biotransformation / Q000187:drug effects; D002021:Buffers; D002384:Catalysis; D002711:Chloride Peroxidase / Q000737:chemistry*; D004143:Dioctyl Sulfosuccinic Acid / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D004655:Emulsions; D004795:Enzyme Stability / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000737:chemistry / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D016877:Oxidants / Q000494:pharmacology; D010084:Oxidation-Reduction; D020058:Styrene / Q000737:chemistry*; D013379:Substrate Specificity; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature; D014050:Toluene / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D014992:Xylenes / Q000737:chemistry*; D020122:tert-Butylhydroperoxide / Q000737:chemistry / Q000494:pharmacology
chemical_list: D002021:Buffers; D004655:Emulsions; D016877:Oxidants; D013501:Surface-Active Agents; D014992:Xylenes; D014867:Water; D004143:Dioctyl Sulfosuccinic Acid; D014050:Toluene; D020058:Styrene; D020122:tert-Butylhydroperoxide; D006861:Hydrogen Peroxide; D002711:Chloride Peroxidase