Catalysis and inactivation of tyrosinase in its action on hydroxyhydroquinone

del Mar Garcia-Molina, Maria, Muñoz‐Muñoz (Munoz), Jose Luis, Berna, Jose, García-Ruiz, Pedro Antonio, Rodriguez-Lopez, Jose Neptuno and Garcia-Canovas, Francisco (2014) Catalysis and inactivation of tyrosinase in its action on hydroxyhydroquinone. IUBMB Life, 66 (2). pp. 122-127. ISSN 1521-6543

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Hydroxyhydroquinone (HHQ) was characterized kinetically as a tyrosinase substrate. A kinetic mechanism is proposed, in which HHQ is considered as a monophenol or as an o‐diphenol, depending on the part of the molecule that interacts with the enzyme. The kinetic parameters obtained from an analysis of the measurements of the initial steady state rate of 2‐hydroxy p‐benzoquinone formation were urn:x-wiley::media:iub1250:iub1250-math-0001= 229.0 ± 7.7 s−1 and urn:x-wiley::media:iub1250:iub1250-math-0002= 0.40 ± 0.05 mM. Furthermore, the action of tyrosinase on HHQ led to the enzyme's inactivation through a suicide inactivation mechanism. This suicide inactivation process was characterized kinetically by urn:x-wiley::media:iub1250:iub1250-math-0003 (the apparent maximum inactivation constant) and r, the number of turnovers made by 1 mol of enzyme before being inactivated. The values of urn:x-wiley::media:iub1250:iub1250-math-0004 and r were (8.2 ± 0.1) × 10−3 s−1 and 35,740 ± 2,548, respectively.

Item Type: Article
Uncontrolled Keywords: tyrosinase; hydroquinone; hydroxyhydroquinone; catalysis;suicide inactivation
Subjects: C700 Molecular Biology, Biophysics and Biochemistry
Department: Faculties > Arts, Design and Social Sciences > Social Sciences
Depositing User: Elena Carlaw
Date Deposited: 11 Feb 2019 11:09
Last Modified: 10 Oct 2019 23:48

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