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Publication Abstract from PubMed

Guaiacol is a universal substrate for all peroxidases, and its use in a simple colorimetric assay has wide applications. However, its exact binding location has never been defined. Here we report the crystal structures of guaiacol bound to cytochrome c peroxidase (CcP). A related structure with phenol bound is also presented. The CcP-guaiacol and CcP-phenol crystal structures show that both guaiacol and phenol bind at sites distinct from the cytochrome c binding site and from the delta-heme edge, which is known to be the binding site for other substrates. Although neither guaiacol nor phenol is seen bound at the delta-heme edge in the crystal structures, inhibition data and mutagenesis strongly suggest that the catalytic binding site for aromatic compounds is the delta-heme edge in CcP. The functional implications of these observations are discussed in terms of our existing understanding of substrate binding in peroxidases [Gumiero A et al. (2010) Arch Biochem Biophys 500, 13-20].

Crystal structure of guaiacol and phenol bound to a heme peroxidase.,Murphy EJ, Metcalfe CL, Nnamchi C, Moody PC, Raven EL FEBS J. 2012 May;279(9):1632-9. doi: 10.1111/j.1742-4658.2011.08425.x. Epub 2011 , Dec 5. PMID:22093282^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.