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Dopamine β‐hydroxylase inactivation generates a protein‐bound quinone derivative
Author(s) -
Slama Patrick,
Jabre Frédéric,
Tron Thierry,
Réglier Marius
Publication year - 2001
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(01)02147-0
Subject(s) - chemistry , dopamine , quinone , derivative (finance) , biochemistry , stereochemistry , biology , endocrinology , financial economics , economics
Bovine dopamine β‐hydroxylase (DbH) was inactivated by hydrogen peroxide and ascorbate in the presence of dioxygen. Both inactivated forms of the enzyme were investigated. We could highlight the presence of a quinone derivative bound to the protein, assumed as being dopa‐quinone, that is absent from active enzyme. Such results suggest that a tyrosinyl radical transiently forms during catalysis. Moreover we could show that addition of substrate tyramine to H 2 O 2 incubates is responsible for a partial protection of DbH against inactivation.