@misc{oai:niigata-u.repo.nii.ac.jp:00004789,
 author = {Sasagawa, Keisuke},
 month = {Mar},
 note = {The oxygen (O2) binding properties of bovine Hemoglobin (Hb) were examined and compared with those of human Hb. Bovine Hb had intrinsically lower oxygen affinity than human Hb, and the affinity was lowered further with increasing concentrations of chloride ion (Cl-) and 2,3-diphosphoglycerate (DPG). The influence of Cl- on P50 was greater in bovine Hb than in human Hb at the physiological concentrations of Cl- and DPG and at 37℃. nmax was reduced at high Cl- concentrations, whereas it was little effected by DPG. An increase in Cl- concentration enhanced the Bohr effect, the magnitude of which reached a maximum at 0.1 M Cl- and 20℃. This concentration was nearly equal to that at the highest slope of the log P50 vs. log [Cl-] plot, and was equal to the physiological Cl- concentration (0.1M) in bovine blood. The influence of Cl- on the Bohr effect in bovine Hb was similar to that in human Hb, and was independent of temperature. On the other hand, in the absence of Cl-, bovine Hb was sensitive to DPG. An increase in DPG concentration enhanced the Bohr effect, which reached a maximum at 3 mM DPG and 20℃. This concentration was nearly equal to that at the highest slope of the log P50 vs. log [DPG] plot. The influence of DPG on the Bohr effect in bovine Hb was similar to that in human Hb. At low DPG concentrations, the influence of DPG on the Bohr effect became small with increasing temperature, whereas at high DPG concentrations, the DPG effect was insensitive to temperature changes. At the physiological DPG concentration of 0.5 mM, increases in both Cl- concentration and temperature diminished the DPG effect. At the physiological concentrations of Cl- and DPG, the Bohr effect was -0.36 at 37℃. These results indicate that Cl- and temperature are important determinants of O2 affinity and the magnitude of the Bohr shift of bovine Hb. In the case of human Hb, the influence of DPG on the Bohr effect is greater than that of Cl-, and at 37℃, in the presence of the physiological concentration of DPG, the influence of Cl- on the Bohr effect is abolished. The ΔH value of bovine Hb, which was measured at the physiological concentrations of Cl- and DPG to be approximately -5.8 kcal/mol, is markedly lower than that of human Hb (approximately -8.1 kcal/mol). Low-temperature sensitivity contributes to O2 unloading in cooled peripheral tissues. At the physiological concentration of DPG, the effect of Cl- on P50 in bovine Hb at 37℃ is markedly higher than that in human Hb. This results seem to indicate that the Cl- effect on P50 in bovine Hb contributes to the unloading of O2 from Hb with marked influence of Cl- during the Cl- shift in bovine red blood cell., 新大院博（理）甲第257号, 新大院博（理）甲第257号},
 title = {Influence of Allosteric Effectors and Temperature on Oxygen Binding Properties and Bohr Effect of Bovine Hemoglobin},
 year = {2006}
}