1W4Y

Ferrous horseradish peroxidase C1A in complex with carbon monoxide

Summary for 1W4Y

• Entry DOI: 10.2210/pdb1w4y/pdb
• Related: 1ATJ 1GW2 1GWO 1GWT 1GWU 1GX2 1H55 1H57 1H58 1H5A 1H5C 1H5D 1H5E 1H5F 1H5G 1H5H 1H5I 1H5J 1H5K 1H5L 1H5M 1HCH 1KZM 1W4W 2ATJ 3ATJ 4ATJ 6ATJ 7ATJ
• Descriptor: HORSERADISH PEROXIDASE C1A, PROTOPORPHYRIN IX CONTAINING FE, CALCIUM ION, ... (5 entities in total)
• Functional Keywords: oxidoreductase, carbon monoxide, calcium, ferrous state, glycoprotein, heme, horseradish, iron, multigene family, peroxidase, pyrrolidone carboxylic acid
• Biological source: ARMORACIA RUSTICANA (HORSERADISH)
• Total number of polymer chains: 1
• Total formula weight: 36376.78

Authors

Carlsson, G.H.,Nicholls, P.,Svistunenko, D.,Berglund, G.I.,Hajdu, J. (deposition date: 2004-08-03, release date: 2005-01-19, Last modification date: 2024-11-13)

Primary citation

Carlsson, G.H.,Nicholls, P.,Svistunenko, D.,Berglund, G.I.,Hajdu, J.
Complexes of Horseradish Peroxidase with Formate, Acetate, and Carbon Monoxide
Biochemistry, 44:635-, 2005

PubMed Abstract: Carbon monoxide, formate, and acetate interact with horseradish peroxidase (HRP) by binding to subsites within the active site. These ligands also bind to catalases, but their interactions are different in the two types of enzymes. Formate (notionally the "hydrated" form of carbon monoxide) is oxidized to carbon dioxide by compound I in catalase, while no such reaction is reported to occur in HRP, and the CO complex of ferrocatalase can only be obtained indirectly. Here we describe high-resolution crystal structures for HRP in its complexes with carbon monoxide and with formate, and compare these with the previously determined HRP-acetate structure [Berglund, G. I., et al. (2002) Nature 417, 463-468]. A multicrystal X-ray data collection strategy preserved the correct oxidation state of the iron during the experiments. Absorption spectra of the crystals and electron paramagnetic resonance data for the acetate and formate complexes in solution correlate electronic states with the structural results. Formate in ferric HRP and CO in ferrous HRP bind directly to the heme iron with iron-ligand distances of 2.3 and 1.8 A, respectively. CO does not bind to the ferric iron in the crystal. Acetate bound to ferric HRP stacks parallel with the heme plane with its carboxylate group 3.6 A from the heme iron, and without an intervening solvent molecule between the iron and acetate. The positions of the oxygen atoms in the bound ligands outline a potential access route for hydrogen peroxide to the iron. We propose that interactions in this channel ensure deprotonation of the proximal oxygen before binding to the heme iron.

PubMed: 15641789
DOI: 10.1021/BI0483211

Experimental method

X-RAY DIFFRACTION (1.6 Å)