Immobilization of uricase upon polypyrrole-ferrocenium film

ÇETE S., Yasar A., ARSLAN F.

ARTIFICIAL CELLS BLOOD SUBSTITUTES AND BIOTECHNOLOGY, vol.35, no.6, pp.607-620, 2007 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 35 Issue: 6
  • Publication Date: 2007
  • Doi Number: 10.1080/10731190701378634
  • Journal Name: ARTIFICIAL CELLS BLOOD SUBSTITUTES AND BIOTECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.607-620
  • Keywords: glutaraldehyde, immobilization, polypyrrole, uricase, GLUCOSE-OXIDASE, AMPEROMETRIC BIOSENSOR, CONDUCTING POLYMERS, ACID DETERMINATION, URATE OXIDASE, ENZYME, ELECTRODE, PURIFICATION, CHEMISTRY, MATRICES
  • Gazi University Affiliated: Yes

Abstract

In this study, uricase was immobilized by a glutaraldehyde/gelatine crosslinking procedure onto polypyrrole film. The K, value for immobilized enzyme 0.44mM was much higher than that of the free enzyme 0.39mM. 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.