The toolbox of Auricularia auricula-judae dye-decolorizing peroxidase - Identification of three new potential substrate-interaction sites.

Auricularia auricula-judae

Immune support

SpeciesWood Ear, Kikurage

JournalArchives of biochemistry and biophysics

Year2015

Key points

Dye-decolorizing peroxidases (DyPs) such as AauDyPI from the fungus Auricularia auricula-judae are able to oxidize substrates of different kinds and sizes
A crystal structure of an AauDyPI-imidazole complex gives insight into the binding patterns of organic molecules within the heme cavity of a DyP. Several small N-containing heterocyclic aromatics are shown to bind in the AauDyPI heme cavity, hinting to susceptibility of DyPs to azole-based inhibitors similar to cytochromes P450
Imidazole is confirmed as a competitive inhibitor with regard to peroxide binding
In contrast, bulky substrates such as anthraquinone dyes are converted at the enzyme surface
In the crystal structure a substrate analog, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), binds to a tyrosine-rich hollow harboring Y25, Y147, and Y337
Spin trapping with a nitric oxide donor uncovers Y229 as an additional tyrosine-based radical center in AauDyPI. Multi-frequency EPR spectroscopy further reveals the presence of at least one intermediate tryptophanyl radical center in activated AauDyPI with W377 as the most likely candidate

Metadata-grounded summary

Citation abstract

Dye-decolorizing peroxidases (DyPs) such as AauDyPI from the fungus Auricularia auricula-judae are able to oxidize substrates of different kinds and sizes. A crystal structure of an AauDyPI-imidazole complex gives insight into the binding patterns of organic molecules within the heme cavity of a DyP. Several small N-containing heterocyclic aromatics are shown to bind in the AauDyPI heme cavity, hinting to susceptibility of DyPs to azole-based inhibitors similar to cytochromes P450. Imidazole is confirmed as a competitive inhibitor with regard to peroxide binding. In contrast, bulky substrates such as anthraquinone dyes are converted at the enzyme surface. In the crystal structure a substrate analog, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), binds to a tyrosine-rich hollow harboring Y25, Y147, and Y337. Spin trapping with a nitric oxide donor uncovers Y229 as an additional tyrosine-based radical center in AauDyPI. Multi-frequency EPR spectroscopy further reveals the presence of at least one intermediate tryptophanyl radical center in activated AauDyPI with W377 as the most likely candidate.

Citation

Strittmatter E, Serrer K, Liers C, Ullrich R, Hofrichter M, Piontek K, et al. (2015). The toolbox of Auricularia auricula-judae dye-decolorizing peroxidase - Identification of three new potential substrate-interaction sites. Archives of biochemistry and biophysics https://doi.org/10.1016/j.abb.2014.12.016 PMID: 25542606

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