The Effects on Oxygen Affinity and Gelation of Hemoglobin S Crosslinked by Reaction with Methyl Acetimidate
Autor: | T. L. Chao, T. G. Gabuzda, T. Gelbart, M. R. Berenfeld |
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Rok vydání: | 1981 |
Předmět: |
Erythrocytes
Chemical Phenomena Hemoglobin Sickle Clinical Biochemistry Size-exclusion chromatography Increased oxygen affinity Anemia Sickle Cell Oxygen affinity Methyl acetimidate Antisickling Agents Imidoesters medicine Humans Amino Acids Genetics (clinical) Hemoglobin s Chromatography Chemistry Biochemistry (medical) food and beverages Hematology medicine.disease Sickle cell anemia Molecular Weight Oxygen Cross-Linking Reagents Deoxy hb Trinitrobenzenesulfonic Acid Chromatography Gel Hemoglobin |
Zdroj: | Hemoglobin. 5:47-72 |
ISSN: | 1532-432X 0363-0269 |
DOI: | 10.3109/03630268108996910 |
Popis: | The contribution of the high molecular weight hemoglobin (HMW Hb) to the antisickling effect produced by treatment of sickle cell erythrocytes with methyl acetimidate (MAI) was investigated. Erythrocytes obtained from sickle cell anemia and normal individuals were incubated with varying concentrations of MAI. The presence of intermolecularly crosslinked HMW Hb was detected by gel filtration of dialyzed hemolysates obtained from the incubated cells. HMW Hb has an increased oxygen affinity and a decreased Hill constant. Intermolecular crosslinking per se was shown to have no additional effect on Hb oxygen affinity other than that due to Hb amino group modification. Modified deoxy Hb S of normal molecular weight has a higher minimum gel concentration (MGC) than control deoxy Hb S. Deoxy HMW Hb did not gel at intracellular Hb concentrations. Therefore, the intracellular concentration of deoxy Hb S that gels necessarily decreases as the HMW Hb concentration increases. This "excluded volume effect" of the non-gelling Hb would be expected to increase the MGC of completely deoxygenated hemolysate obtained from the treated cells. The HMW Hb contributes to the inhibition of sickling resulting from treatment of sickle erythrocyte with MAI by increasing both MGC and oxygen affinity of the modified Hb. |
Databáze: | OpenAIRE |
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