Biochemical evidence of both copper chelation and oxygenase activity at the histidine brace
Journal article, 2020

Lytic polysaccharide monooxygenase (LPMO) and copper binding protein CopC share a similar mononuclear copper site. This site is defined by an N-terminal histidine and a second internal histidine side chain in a configuration called the histidine brace. To understand better the determinants of reactivity, the biochemical and structural properties of a well-described cellulose-specific LPMO from Thermoascus aurantiacus (TaAA9A) is compared with that of CopC from Pseudomonas fluorescens (PfCopC) and with the LPMO-like protein Bim1 from Cryptococcus neoformans. PfCopC is not reduced by ascorbate but is a very strong Cu(II) chelator due to residues that interacts with the N-terminus. This first biochemical characterization of Bim1 shows that it is not redox active, but very sensitive to H2O2, which accelerates the release of Cu ions from the protein. TaAA9A oxidizes ascorbate at a rate similar to free copper but through a mechanism that produce fewer reactive oxygen species. These three biologically relevant examples emphasize the diversity in how the proteinaceous environment control reactivity of Cu with O2.

Author

Søren Brander

University of Copenhagen

Istvan Horvath

Chalmers, Biology and Biological Engineering, Chemical Biology

Johan Ipsen

University of Copenhagen

Ausra Peciulyte

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

Lisbeth Olsson

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

Cristina Hernández-Rollán

Technical University of Denmark (DTU)

Morten H.H. Nørholm

Technical University of Denmark (DTU)

Susanne Mossin

Technical University of Denmark (DTU)

Leila Lo Leggio

University of Copenhagen

Corinna Probst

Duke University

Dennis J. Thiele

Duke University

Katja Salomon Johansen

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

University of Copenhagen

Scientific Reports

2045-2322 (ISSN)

Vol. 10 1 16369

Subject Categories

Biochemistry and Molecular Biology

Biophysics

Structural Biology

DOI

10.1038/s41598-020-73266-y

More information

Latest update

10/22/2020