Pentacoordination of the heme iron of Arthromyces ramosus peroxidase shown by a 1.8 A resolution crystallographic study at pH 4.5.Kunishima, N., Amada, F., Fukuyama, K., Kawamoto, M., Matsunaga, T., Matsubara, H.
(1996) FEBS Lett. 378: 291-294
- PubMed: 8557120
- PubMed Abstract:
- Crystal Structures of Cyanide-and Triiodide-Bound Forms of Arthromyces Ramosus Peroxidase at Different Ph Values. Perturbations of Active Site Residues and Their Implication in Enzyme Catalysis
Fukuyama, K.,Kunishima, N.,Amada, F.,Kubota, T.,Matsubara, H.
(1995) J.Biol.Chem. 270: 21884
- Crystal Structure of the Fungal Peroxidase from Arthromyces Ramosus at 1.9 A Resolution. Structural Comparisons with the Lignin and Cytochrome C Peroxidases
Kunishima, N.,Fukuyama, K.,Matsubara, H.,Hatanaka, H.,Shibano, Y.,Amachi, T.
(1994) J.Mol.Biol. 235: 331
- Crystallization and Preliminary X-Ray Diffraction Studies of Peroxidase from a Fungus Arthromyces Ramosus
Kunishima, N.,Fukuyama, K.,Wakabayashi, S.,Sumida, M.,Takaya, M.,Shibano, Y.,Amachi, T.,Matsubara, H.
(1993) Proteins 15: 216
In the presence of ammonium sulfate the absorption spectra of a peroxidase from the fungus Arthromyces ramosus (ARP) showed that the low-spin component increased as the pH increased from 6.0 to 9.0, whereas in its absence ARP remained in the high-spi ...
In the presence of ammonium sulfate the absorption spectra of a peroxidase from the fungus Arthromyces ramosus (ARP) showed that the low-spin component increased as the pH increased from 6.0 to 9.0, whereas in its absence ARP remained in the high-spin state in the pH range investigated. The crystal structure of ARP at pH 4.5 in the presence of ammonium sulfate at 1.8 A resolution showed that the electron density at the 6th position of the heme iron seen at pH 7.5 had disappeared and that the iron atom deviated markedly from the heme plane. These observations strongly suggest that under physiological conditions the heme of ARP is in the pentacoordinated high-spin state and that at a high pH the heme iron is able to bind ammonia, forming the low-spin state. The location of the water molecule at the distal side of the heme in peroxidases is also discussed.
Department of Biology, Faculty of Science, Osaka University, Japan.