Characterization of a New Glyoxal Oxidase from the Thermophilic Fungus Myceliophthora thermophila M77: Hydrogen Peroxide Production Retained in 5-Hydroxymethylfurfural Oxidation

Author(s)

Seiki Kadowaki, Marco Antonio ^{[1, 2, 3]} ; de Godoy, Mariana Ortiz ^{[1, 2, 3]} ; Kumagai, Patricia Suemy ^[3] ; da Costa-Filho, Antonio Jose ^[4] ; Mort, Andrew ^{[1, 2]} ; Prade, Rolf Alexander ^{[1, 2]} ; Polikarpov, Igor ^[3]

Affiliation

^[1] Oklahoma State Univ, Dept Microbiol & Mol Genet, Stillwater, OK 74078 - USA

^[2] Oklahoma State Univ, Dept Biochem & Mol Biol, Stillwater, OK 74078 - USA

^[3] Univ Sao Paulo, Sao Carlos Inst Phys, Av Trabalhador Sao Carlense 400, BR-13566590 Sao Carlos, SP - Brazil

^[4] Univ Sao Paulo, Ribeirao Preto Sch Philosophy Sci & Literature, Dept Phys, BR-14040901 Ribeirao Preto - Brazil

• Document type: Journal article
• Source: CATALYSTS; v. 8, n. 10 OCT 2018.
• Web of Science Citations: 1

Abstract

Myceliophthora thermophyla is a thermophilic industrially relevant fungus that secretes an assortment of hydrolytic and oxidative enzymes for lignocellulose degradation. Among them is glyoxal oxidase (MtGLOx), an extracellular oxidoreductase that oxidizes several aldehydes and a-hydroxy carbonyl substrates coupled to the reduction of O-2 to H2O2. This copper metalloprotein belongs to a class of enzymes called radical copper oxidases (CRO) and to the ``auxiliary activities{''} subfamily AA5\_1 that is based on the Carbohydrate-Active enZYmes (CAZy) database. Only a few members of this family have been characterized to date. Here, we report the recombinant production, characterization, and structure-function analysis of MtGLOx. Electron Paramagnetic Resonance (EPR) spectroscopy confirmed MtGLOx to be a radical-coupled copper complex and small angle X-ray scattering (SAXS) revealed an extended spatial arrangement of the catalytic and four N-terminal WSC domains. Furthermore, we demonstrate that methylglyoxal and 5-hydroxymethylfurfural (HMF), a fermentation inhibitor, are substrates for the enzyme. (AU)

• FAPESP's process: 15/13684-0 - Structural and functional studies of enzymes that participate in complex carbohydrates synthesis and degradation
• Grantee: Igor Polikarpov
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 11/20505-4 - Two important classes of glycosyl hydrolases: functional studies and structural analysis
• Grantee: Marco Antonio Seiki Kadowaki
• Support Opportunities: Scholarships in Brazil - Post-Doctoral