| Autor: |
Garel, M C, Domenget, C, Caburi-Martin, J, Prehu, C, Galacteros, F, Beuzard, Y |
| Zdroj: |
Journal of Biological Chemistry; November 1986, Vol. 261 Issue: 31 p14704-14709, 6p |
| Abstrakt: |
Thiol reagents react with cysteine beta 93 of hemoglobin and as a result increase the oxygen affinity of hemoglobin. In the present studies we have used a thiol-disulfide exchange between mixed disulfides of hemoglobin and reduced glutathione to attach intracellular glutathione to hemoglobin and to study its antisickling properties. The rates of production of glutathionyl hemoglobin (G-Hb) depend on the structure of the thiol reagent linked to cysteine beta 93. Up to 25% G-Hb can be produced in normal and sickle red cells because of the high intracellular concentration of reduced glutathione. This high level of G-Hb in normal cells increases the oxygen affinity by about 35% and reduces heme-heme interactions. In sickle cells the increased oxygen affinity is associated with an inhibition of sickling of about 70% at 21 mm Hg. Inhibition of polymerization of deoxy HbS is also due to a direct inhibition of intermolecular contacts in the fibers as demonstrated by the increased solubility and the increased delay time of G-HbS compared to deoxy HbS. |
| Databáze: |
Supplemental Index |
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