Structural characterization of horseradish peroxidase using EXAFS spectroscopy. Evidence for Fe=O ligation in compounds I and II

Journal Article · Wed Nov 26 00:00:00 EST 1986 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00284a054· OSTI ID:7203811

Penner-Hahn, J E; Eble, K S; McMurry, T J; Renner, M; Balch, A L; Groves, J T; Dawson, J H; Hodgson, K O

Extended X-ray absorption fine structure spectroscopy has been utilized to determine the structural environment of the heme iron sites in horseradish peroxidase compounds I and II. For comparison, analogous studies have been undertaken on putative ferryl (Fe/sup IV/=O) porphyrin model compounds and on crystallographically characterized Cr/sup IV/=O and Cr/sup V/ identical with N porphyrins. In a preliminary communication, they suggested that a short ca. 1.6 A Fe-O bond is present in the high valent forms of both the enzyme and the synthetic porphyrins. The present work demonstrates unambiguously that a short, ca. 1.64 A, Fe-O bond length is present both in HRP compounds I and II and in their synthetic analogues. This structure is consistent only with an oxo-ferryl (Fe=O) complex as the active oxygen species in horseradish peroxidase. The structural details, their implications for heme protein mediated oxygen activation, and the difference between their results and those recently published by other workers.

• Research Organization: Univ. of Michigan, Ann Arbor
• OSTI ID: 7203811
• Journal Information: J. Am. Chem. Soc.; (United States), Vol. 108:24
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
HEME
CRYSTAL STRUCTURE
MOLECULAR STRUCTURE
PEROXIDASES
PORPHYRINS
ABSORPTION SPECTROSCOPY
BOND LENGTHS
EXPERIMENTAL DATA
IRON
OXYGEN
X RADIATION
CARBOXYLIC ACIDS
DATA
DIMENSIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
ENZYMES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INFORMATION
IONIZING RADIATIONS
LENGTH
METALS
NONMETALS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDOREDUCTASES
PIGMENTS
RADIATIONS
SPECTROSCOPY
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties