Two Fusarium copper radical oxidases with high activity on aryl alcohols

Biotechnology for Biofuels

Jason E. Hein¹  Ryan Chung¹  Paul Mulyk¹  Mickael Lafond²  Fan Roderick Xia²  Maria Cleveland²  Harry Brumer² 

[1] Department of Chemistry, University of British Columbia;Michael Smith Laboratories, University of British Columbia;

关键词: Copper radical oxidase;    Aryl alcohol oxidase;    Galactose oxidase;    Biocatalysis;    Metalloenzyme;   

DOI  :  10.1186/s13068-021-01984-0

来源: DOAJ

【 摘 要 】

Abstract Background Biomass valorization has been suggested as a sustainable alternative to petroleum-based energy and commodities. In this context, the copper radical oxidases (CROs) from Auxiliary Activity Family 5/Subfamily 2 (AA5_2) are attractive biocatalysts for the selective oxidation of primary alcohols to aldehydes. Originally defined by the archetypal galactose 6-oxidase from Fusarium graminearum, fungal AA5_2 members have recently been shown to comprise a wide range of specificities for aromatic, aliphatic and furan-based alcohols. This suggests a broader substrate scope of native CROs for applications. However, only 10% of the annotated AA5_2 members have been characterized to date. Results Here, we define two homologues from the filamentous fungi Fusarium graminearum and F. oxysporum as predominant aryl alcohol oxidases (AAOs) through recombinant production in Pichia pastoris, detailed kinetic characterization, and enzyme product analysis. Despite possessing generally similar active-site architectures to the archetypal FgrGalOx, FgrAAO and FoxAAO have weak activity on carbohydrates, but instead efficiently oxidize specific aryl alcohols. Notably, both FgrAAO and FoxAAO oxidize hydroxymethyl furfural (HMF) directly to 5-formyl-2-furoic acid (FFCA), and desymmetrize the bioproduct glycerol to the uncommon L-isomer of glyceraldehyde. Conclusions This work expands understanding of the catalytic diversity of CRO from AA5_2 to include unique representatives from Fusarium species that depart from the well-known galactose 6-oxidase activity of this family. Detailed enzymological analysis highlights the potential biotechnological applications of these orthologs in the production of renewable plastic polymer precursors and other chemicals.

【 授权许可】

Unknown