title: Cross-linking of horseradish peroxidase adsorbed on polycationic films: utilization for direct dye degradation.
abstract: Horseradish peroxidase (HRP) was immobilized on the polyaniline (PANI) grafted polyacrylonitrile (PAN) films. The maximum HRP immobilization capacity of the PAN-g-PANI-3 film was 221 μg/cm(2). The HRP-immobilized PAN-g-PANI-3 film retained 79 % of the activity of the same quantity free enzyme. The HRP-immobilized PAN-g-PANI-3 film was operated for the decolorization of two different benzidine-based dyes in the presence of hydrogen peroxide. The maximum decolorization grade was obtained at pH 6.0 for both dyes. The HRP-immobilized PAN-g-PANI-3 film was very effective for removal of Direct Blue-53 compared to Direct Black-38 from aqueous solutions. The immobilized HRP exhibited high resistance to proteolysis by trypsin compared to the free counterpart. Immobilized HRP preserved 83 % of its original activity even after 8 weeks of storage at 4 °C, while the free enzyme lost its initial activity after 3 weeks of storage period.
authors.affiliation: Biochemical Processing and Biomaterial Research Laboratory, Faculty of Sciences, Gazi University, Teknik Okullar, Ankara, Turkey. g_bayramoglu@hotmail.com
authors.forename: Gulay
authors.initials: G
authors.lastname: Bayramoglu
authors.forename: Begum
authors.initials: B
authors.lastname: Altintas
authors.forename: M
authors.initials: M
authors.lastname: Yakup Arica
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry; D008567:Membranes, Artificial; D014343:Trypan Blue / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; D001391:Azo Compounds; D004396:Coloring Agents; D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; C010504:polyacrylonitrile; C015844:direct black 3; D006735:Horseradish Peroxidase; D014343:Trypan Blue