TY - JOUR
T1 - Stoichiometry of the reaction of oxyhemoglobin with nitrite
AU - Kosaka, Hiroaki
AU - Imaizumi, Kazuhiko
AU - Imai, Kiyohiro
AU - Tyuma, Itiro
PY - 1979/11/23
Y1 - 1979/11/23
N2 - During the reaction of oxyhemoglobin (HbO2) with nitrite, the concentration of residual nitrite, nitrate, oxygen, and methemoglobin (Hb+) was determined successively. The results obtained at various pH values indicate the following stoichiometry for the overall reaction: 4HbO2 + 4NO-
2 + → 4Hb+ + 4NO-
3 + O2 + 2H2O (Hb denotes hemoglobin monomer). NO2
- binds with methemoglobin noncooperatively with a binding constant of 340 M-1 at pH 7.4 and 25°C. Thus, the major part of Hb+ produced is aquomethemoglobin, not methemoglobin nitrite, when less than 2 equivalents of nitrite is used for the oxidation.
AB - During the reaction of oxyhemoglobin (HbO2) with nitrite, the concentration of residual nitrite, nitrate, oxygen, and methemoglobin (Hb+) was determined successively. The results obtained at various pH values indicate the following stoichiometry for the overall reaction: 4HbO2 + 4NO-
2 + → 4Hb+ + 4NO-
3 + O2 + 2H2O (Hb denotes hemoglobin monomer). NO2
- binds with methemoglobin noncooperatively with a binding constant of 340 M-1 at pH 7.4 and 25°C. Thus, the major part of Hb+ produced is aquomethemoglobin, not methemoglobin nitrite, when less than 2 equivalents of nitrite is used for the oxidation.
KW - Nitrite
KW - Oxyhemoglobin
KW - Stoichiometry
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U2 - 10.1016/0005-2795(79)90235-6
DO - 10.1016/0005-2795(79)90235-6
M3 - Article
C2 - 41590
AN - SCOPUS:0018716776
SN - 0005-2795
VL - 581
SP - 184
EP - 188
JO - BBA - Protein Structure
JF - BBA - Protein Structure
IS - 1
ER -