Preparation of cross-linked tyrosinase aggregates

Aytar B. S., Bakir U.

PROCESS BIOCHEMISTRY, vol.43, no.2, pp.125-131, 2008 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 43 Issue: 2
  • Publication Date: 2008
  • Doi Number: 10.1016/j.procbio.2007.11.001
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.125-131
  • Keywords: immobilization, mushroom tyrosinase, cross-linked enzyme aggregates, glutaraldehyde, ammonium sulfate, PENICILLIN ACYLASE, MUSHROOM TYROSINASE, ENZYME, IMMOBILIZATION, CLEAS, METHODOLOGY, STABILITY, LINKING, LIPASES
  • Middle East Technical University Affiliated: Yes


Tyrosinase from mushroom was immobilized as a cross-linked enzyme aggregate (CLEA) via precipitation with ammonium sulfate and cross-linking with glutaraldehyde. The effects of precipitation and cross-linking on CLEA activity were investigated and the immobilized tyrosinase was characterized. Sixty percent ammonium sulfate saturation and 2% glutaraldehyde were used; a 3-h cross-linking reaction at room temperature, at pH 7.0 was performed; particle sizes of the aggregates were reduced; consequently, 100% activity recovery was achieved in CLEAs with enhanced thermal and storage stabilities. Slight changes in optimum pH and temperature values of the enzyme were recorded after immobilization. Although immobilization did not affect V-max, substrate affinity of the enzyme increased. Highly stable CLEAs were also prepared from crude mushroom tyrosinase with 100% activity recovery. (c) 2007 Elsevier Ltd. All rights reserved.