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) 20452322 (eISSN)
Vol. 10 1 16369Subject Categories
Biochemistry and Molecular Biology
Biophysics
Structural Biology
DOI
10.1038/s41598-020-73266-y