Characterization of the Preprocessed Copper Site Equilibrium in Amine Oxidase and Assignment of the Reactive Copper Site in Topaquinone Biogenesis.

ABSTRACT: Copper-dependent amine oxidases produce their redox active cofactor, 2,4,5-trihydroxyphenylalanine quinone (TPQ), via the Cu^II-catalyzed oxygenation of an active site tyrosine. This study addresses possible mechanisms for this biogenesis process by presenting the geometric and electronic structure characterization of the Cu^II-bound, prebiogenesis (preprocessed) active site of the enzyme Arthrobacter globiformis amine oxidase (AGAO). Cu^II-loading into the preprocessed AGAO active site is slow ( k_obs = 0.13 h^-1), and is preceded by Cu^II binding in a separate kinetically favored site that is distinct from the active site. Preprocessed active site Cu^II is in a thermal equilibrium between two species, an entropically f

SUBMITTER: Adelson CN 

PROVIDER: S-EPMC6568004 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature