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Evidence for nonhydrogen bonded compound II in cyclic reaction of hemoglobin I from Lucina pectinata with hydrogen peroxide
Author(s) -
De JesúsBonilla Walleska,
RamírezMeléndez Eunice,
Cerda José,
LópezGarriga Juan
Publication year - 2002
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.10082
Subject(s) - chemistry , hydrogen peroxide , ferric , ferrous , heme , moiety , ligand (biochemistry) , raman spectroscopy , hemeprotein , myoglobin , peroxide , medicinal chemistry , photochemistry , inorganic chemistry , nuclear chemistry , stereochemistry , organic chemistry , biochemistry , physics , receptor , optics , enzyme
Abstract Studies that elucidate the behavior of the hemoglobins (Hbs) and myoglobins upon reaction with hydrogen peroxide are essential to the development of oxygen carrier substitutes. Stopped‐flow kinetics and resonance Raman data show that the reaction between hydrogen peroxide and oxygenated and deoxygenated ferric Hb I (oxy‐ and deoxy‐HbI) from Lucina pectinata produce compound I and compound II ferryl species. The rate constants ratio ( k 23 / k 41 ) between the formation of compound II from compound I ( k 23 ) and the oxidation of the ferrous HbI ( k 41 , i.e., 25 M −1 s −1 ) of 12 × 10 −4 M suggests that HbI has a peroxidative capacity for removing H 2 O 2 from solution. Resonance Raman presents the formation of both, met‐aquo‐HbI and compound II ferryl species in the cyclic reaction of HbI with H 2 O 2 . The ferric HbI species is maintained by the presence of H 2 O 2 ; it can produce HbI compound I, or it can be reduced to a deoxy‐HbI derivative to form HbI compound II upon reaction with H 2 O 2 . The compound II ferryl vibration frequency appears at 805 and 769 cm −1 for HbIFe IV 16 O and HbIFe IV 18 O species, respectively. This ferryl mode indicates the absence of hydrogen bonding between the carbonyl group of the distal Q64 and the HbIFe IV O ferryl moiety. The observation suggests that both the trans‐ligand effect and the polarizabilty of the HbI heme pocket are responsible for the observed ferryl oxo vibrational energy. The vibrational mode also suggests that the carbonyl group of the distal Q64 is oriented toward the iron of the heme group, increasing the distal pocket electron density. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 67: 178–185, 2002