Nature of the Ferryl Heme in Compounds I and II

DOI: 10.1074/jbc.M110.183483
PMID: 21062738

Authors: Andrea Gumiero (University of Leicester) , Clive L. Metcalfe (University of Leicester) , Emma Raven (University of Leicester) , Peter C. E. Moody (University of Leicester) , Arwen Pearson (University of Leeds)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Biological Chemistry , VOL 286 , PAGES 1260-1268.

State: Published (Approved)
Published: January 2011
Diamond Proposal Number(s): 6388

Abstract: Heme enzymes are ubiquitous in biology and catalyze a vast array of biological redox processes. The formation of high valent ferryl intermediates of the heme iron (known as Compounds I and Compound II) is implicated for a number of catalytic heme enzymes, but these species are formed only transiently and thus have proved somewhat elusive. In consequence, there has been conflicting evidence as to the nature of these ferryl intermediates in a number of different heme enzymes, in particular the precise nature of the bond between the heme iron and the bound oxygen atom. In this work, we present high resolution crystal structures of both Compound I and Compound II intermediates in two different heme peroxidase enzymes, cytochrome c peroxidase and ascorbate peroxidase, allowing direct and accurate comparison of the bonding interactions in the different intermediates. A consistent picture emerges across all structures, showing lengthening of the ferryl oxygen bond (and presumed protonation) on reduction of Compound I to Compound II. These data clarify long standing inconsistencies on the nature of the ferryl heme species in these intermediates.

Journal Keywords: Cytochrome c; Cytochrome P450; HemeHemoglobin Myoglobin; Peroxidase

Diamond Keywords: Enzymes

Subject Areas: Biology and Bio-materials


Instruments: I04-Macromolecular Crystallography

Other Facilities: ESRF

Added On: 10/01/2011 16:16

Documents:
1-s2.0-S002192582056314X-main.pdf

Discipline Tags:

Structural biology Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)