title: Reversible immobilization of uricase on conductive polyaniline brushes grafted on polyacrylonitrile film.
abstract: Polyacrylonitrile film (PAN) surfaces were modified with chemical polymerization of conductive polyaniline (PANI) in the presence of potassium dichromate as an oxidizing agent. The conductive films were used for immobilization of uricase. The surface resistance of the conductive film in this work was found to be 0.97 kΩ/cm. The maximum amount of immobilized enzyme on conductive film containing 2.4% PANI was about 216 μg/cm(2). The optimum pH for free and immobilized enzymes was observed at 7.0 and 7.5, respectively. The K (m) values for free and immobilized uricase were found to be 94 and 138 μM, respectively. V (max) values were calculated as 1.87 and 1.63 U/mg protein for the free and immobilized enzymes, respectively. Immobilized uricase exhibited ~68% of its original activity even after 2 months of storage at 4 °C while the free enzyme lost its initial activity within 4 weeks.
authors.affiliation: Biochemical Processing and Biomaterial Research Laboratory, Department of Chemistry and Biology, Faculty of Arts and Sciences, Gazi University, Teknikokullar, Ankara, Turkey. g_bayramoglu@hotmail.com
authors.forename: Gülay
authors.initials: G
authors.lastname: Bayramoğlu
authors.forename: Begüm
authors.initials: B
authors.lastname: Altıntaş
authors.forename: M Yakup
authors.initials: MY
authors.lastname: Arıca
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000814:Aniline Compounds / Q000737:chemistry*; D001173:Arthrobacter / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry*; D002384:Catalysis; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D014503:Urate Oxidase / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; D000814:Aniline Compounds; D001426:Bacterial Proteins; D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; C416807:polyaniline; C010504:polyacrylonitrile; D014503:Urate Oxidase