Oxime-functionalized cryogel disks for catalase immobilization


İNANAN T., DEMİR M. N., Karipcin F.

INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES, vol.114, pp.812-820, 2018 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 114
  • Publication Date: 2018
  • Doi Number: 10.1016/j.ijbiomac.2018.04.006
  • Journal Name: INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.812-820
  • Keywords: Catalase, Immobilization, Oxime, COVALENT IMMOBILIZATION, OXIDASE, ENZYME, ACID, COIMMOBILIZATION, ADSORPTION, BIOSENSOR, REMOVAL
  • Dokuz Eylül University Affiliated: Yes

Abstract

Catalase is a protective enzyme against oxidative stress and converts hydrogen peroxide into water and molecular oxygen. In the current study, catalase immobilization was applied onto the oxime-functionalized cryogel disks. Cryogel disks were produced by free radical polymerization. After cutting as circular disks, oxime ligand (4-biphenylchloroglyoxime, BPCGO) was attached and oxime-functionalized cryogel disks were obtained. After optimization of several immobilization parameters such as pH, initial catalase concentration, temperature and ionic strength, maximum catalase load was detected as 261.7 +/- 11.2 mg/g for cryogel disk at pH 5.0. Activity studies indicated that immobilization enhanced the enzyme activity in basic pH region, the temperature range of 15-35 degrees C and at ionic strengths between 0.2 and 1.0 M NaCI. Km was detected as 9.9 and 11.0 mM and V-max was 357.1 and 769.2 mu mol min(-1) for free and immobilized catalase, respectively. k(cat) and Km/k(cat) values showed that immobilization enhanced the catalytic efficiency. Storage stability experiments demonstrated that immobilization increased the usability period. Furthermore, catalase desorption was achieved by 1.0 M NaSCN at pH 8.0 successfully and catalase adsorption capacity of oxime-functionalized cryogel disk was decreased by 9.9% at the end of 5 adsorption-desorption cycle. (C) 2018 Elsevier B.V. All rights reserved.