A Bioelectrocatalysis Method for the Kinetic Measurement of Thermal Inactivation of a Redox Enzyme, Bilirubin Oxidase

• IKEDA Tokuji

  Department of Bioscience, Fukui Prefectural University

• TATSUMI Hirosuke

  Department of Bioscience, Fukui Prefectural University

• KATANO Hajime

  Department of Bioscience, Fukui Prefectural University

• WANIBUCHI Mizue

  Department of Bioscience, Fukui Prefectural University

• HIBI Takao

  Department of Bioscience, Fukui Prefectural University

• KAJINO Tsutomu

  Toyota Central R & D Labs Inc.

Abstract

The thermal stability of a redox enzyme, bilirubin oxidase (BOD), has been quantitatively evaluated by measuring the inactivation kinetics of BOD at several temperatures. The enzyme activity is directly related to the mediated bioelectrocatalytic current for the BOD-catalyzed reduction of O₂. Thus, the inactivation process is measured by the time-dependent decrease in the bioelectrocatalytic current. The results reveal that the inactivation obeys first-order kinetics, whose rate constants (k) are determined at pH 7.0 and at 50 - 70°C. The half life of BOD activity, calculated from the k value at 50°C is 114 min, which is in harmony with the thermal-stability data given in a catalog by Amano Enzyme Inc. The bioelectrocatalysis method allows in situ measurements of the inactivation kinetics in the period of a few minutes at relatively high temperatures. The rate constants show a large temperature dependence, leading to a large Arrhenius activation energy (E_A) of 221 kJ mol^-1. The activation Gibbs energy (ΔG^≠), activation enthalpy (ΔH^≠), and activation entropy (ΔS^≠) are also determined.

Journal

• Analytical Sciences

  Analytical Sciences 24 (2), 237-241, 2008

  The Japan Society for Analytical Chemistry

Keywords

• Analytical Chemistry

Details

• CRID: 1390001204258436096
• NII Article ID: 130004441607
• NII Article ID: 10021098450
• NII Book ID: AA10500785
• DOI: 10.2116/analsci.24.237
• COI: 1:CAS:528:DC%2BD1cXit1Ogu7s%3D
• ISSN: 13482246
• ISSN: 09106340
• NDL BIB ID: 9362909
• PubMed: 18270415
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I9362909
• Web Site: https://link.springer.com/content/pdf/10.2116/analsci.24.237.pdf
• Web Site: https://link.springer.com/article/10.2116/analsci.24.237/fulltext.html
• Web Site: https://www.jstage.jst.go.jp/article/analsci/24/2/24_2_237/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • PubMed
  • CiNii Articles
• Abstract License Flag: Disallowed