The copper-containing amine oxidases (CAOs) are a diverse family of enzymes which catalyze the oxidative deamination of primary amines. In mammals, classes of CAOs have been directly linked with chronic diabetic disorders and heart failure, making them a target for pharmaceutical investigation. CAOs are produced in an initially immature, inactive form. To become functional, a tyrosine sidechain from a specific active site residue must be converted into a redox-active cofactor, 2,4,5-trihydroxyphenylalaninequinone (TPQ). The process of cofactor maturation (referred to as biogenesis) occurs by a self-processing mechanism within the enzyme, and is relatively unexplored. This proposal details four sets of experiments aimed at understanding the TPQ biogenesis mechanism in a CAO from yeast (Hansenula polymorpha). Specifically, the goals are: (1) to characterize an intermediate in biogenesis; (2) to probe the electronic character of the active site Cu(II); (3) to elucidate a site of dioxygen binding; (4) to define roles of active site residues in biogenesis.
| Chen, Zhi-Wei; Datta, Saumen; Dubois, Jennifer L et al. (2010) Mutation at a strictly conserved, active site tyrosine in the copper amine oxidase leads to uncontrolled oxygenase activity. Biochemistry 49:7393-402 |
| DuBois, Jennifer L; Klinman, Judith P (2006) Role of a strictly conserved active site tyrosine in cofactor genesis in the copper amine oxidase from Hansenula polymorpha. Biochemistry 45:3178-88 |
| Dubois, Jennifer L; Klinman, Judith P (2005) Mechanism of post-translational quinone formation in copper amine oxidases and its relationship to the catalytic turnover. Arch Biochem Biophys 433:255-65 |
| DuBois, Jennifer L; Klinman, Judith P (2005) The nature of O2 reactivity leading to topa quinone in the copper amine oxidase from Hansenula polymorpha and its relationship to catalytic turnover. Biochemistry 44:11381-8 |
