Identification of two histidines as copper ligands in Streptomyces glaucescens tyrosinase

Détails

ID Serval
serval:BIB_134F73ED0D05
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Identification of two histidines as copper ligands in Streptomyces glaucescens tyrosinase
Périodique
Biochemistry
Auteur⸱e⸱s
Huber  M., Lerch  K.
ISSN
0006-2960 (Print)
Statut éditorial
Publié
Date de publication
07/1988
Volume
27
Numéro
15
Pages
5610-5
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Jul 26
Résumé
The physiochemical properties of wild type and two mutants of Streptomyces glaucescens tyrosinase are reported. The native enzyme contains two coppers at the active site which are EPR nondetectable. The two coppers react stoichiometrically with one hydrogen peroxide molecule giving rise to oxytyrosinase. Its optical features are similar to those reported earlier for a molluscan hemocyanin. The two mutants in which histidine-62 and -189 were changed to asparagine by site-directed mutagenesis have lost their enzymatic activity and their ability to bind oxygen and contain only one copper ion which is fully EPR detectable. The EPR parameters indicate that the remaining copper is in a tetragonally distorted ligand environment. These data are in agreement with His-62 and His-189 serving as copper ligands in S. glaucescens tyrosinase.
Mots-clé
Amino Acid Sequence *Catechol Oxidase Circular Dichroism *Copper DNA Mutational Analysis Electron Spin Resonance Spectroscopy *Histidine Ligands Molecular Sequence Data *Monophenol Monooxygenase Protein Binding Recombinant Proteins Spectrum Analysis Streptomyces/*enzymology
Pubmed
Web of science
Création de la notice
25/01/2008 16:39
Dernière modification de la notice
20/08/2019 12:41
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