| Autor: |
Antonini, Eraldo, Condò, Savorio G., Giardina, Bruno, Ioppolo, Carmela, Bhrtollini, Alberto |
| Předmět: |
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| Zdroj: |
European Journal of Biochemistry; 1/4/82, Vol. 121 Issue 2, p325-328, 4p |
| Abstrakt: |
The present paper reports data for the effect of pH and D-glycerate 2,3-bisphosphate (D-glycerate-2,3-P2) on the oxygen equilibrium of normal and SH(β93)-modified human hemoglobin. At sufficiently high D-glycerate- 2,3-P2 concentrations, both oxy and deoxy forms of HbA are saturated with the organic phosphate at all pH values between 6 and 9. Furthermore the difference in the affinity for D-glycerate-2,3-P2 between deoxy and oxy hemoglobin remains constant with pH, implying that the pK values of the Bohr effect groups in deoxy and oxyhemoglobin are not affected by the presence of D-glycerate-2,3-P2 on the hemoglobin molecule. In the hemoglobins modified in position β93, the difference in affinity between deoxy and oxy hemoglobin for D-glycerate-2.3-P2 decreases with decrease in pH due mainly to a decrease in the affinity of the deoxy form for D-glycerate-2,3-P2. The effect of the chemical modification appears to be primarily a change in pK of a Bohr group in deoxy hemoglobin which is especially pronounced in the presence of phosphates. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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