title: Immobilization of uricase upon polypyrrole-ferrocenium film.
abstract: In this study, uricase was immobilized by a glutaraldehyde/gelatine crosslinking procedure onto polypyrrole film. The K(m) value for immobilized enzyme 0.44 mM was much higher than that of the free enzyme 0.39 mM. V(max) values were 8.4 x 10(-2) mM/dak and 7.1 x 10(-2) mM/dak for free and immobilized enzyme, respectively. The optimal pH values for free and immobilized enzymes were 8.5 and 8.0, respectively. The optimum temperature for both free and immobilized uricase was 35 degrees C and 55 degrees C. The enzyme activity after storage for 7 weeks was found to be 42% and 49% of the initial activity values for free and immobilized enzymes, respectively. The amperometric current obtained after 30 measurements at a constant uric acid concentration of 5.0 x 10(-5) M was found to be 77.7% of initial activity.
authors: Department of Chemistry, Faculty of Arts and Sciences, Gazi University, Ankara, Turkey. scete@gazi.edu.tr
authors: Servet
authors: S
authors: Cete
authors: Ahmet
authors: A
authors: Yaşar
authors: Fatma
authors: F
authors: Arslan
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism / Q000502:physiology; D005296:Ferrous Compounds / Q000737:chemistry* / Q000378:metabolism; D005780:Gelatin / Q000737:chemistry; D005976:Glutaral / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism; D011758:Pyrroles / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature; D014503:Urate Oxidase / Q000378:metabolism* / Q000502:physiology*
chemical_list: D001672:Biocompatible Materials; D004800:Enzymes, Immobilized; D005296:Ferrous Compounds; D011108:Polymers; D011758:Pyrroles; C015233:gelatin film; C064804:ferrocenium; C067635:polypyrrole; D005780:Gelatin; D014503:Urate Oxidase; D005976:Glutaral