Factors affecting the synthesis of 2,3-diphosphoglycerate in hemolysates of human erythrocytes
| Autor: | Normand L. Fortier, Fabian J. Lionetti, Janet F. Forstner |
|---|---|
| Rok vydání: | 1968 |
| Předmět: |
Erythrocytes
Time Factors Chemical Phenomena Ph optimum Bicarbonate Preservation Biological Biophysics Glyceraldehyde Hemolysis Biochemistry Phosphates chemistry.chemical_compound Adenosine Triphosphate Refrigeration Adenine nucleotide Humans Diphosphoglycerate Pyruvates Molecular Biology chemistry.chemical_classification Phosphoglycerate kinase Adenine Nucleotides Phosphotransferases Hydrogen-Ion Concentration NAD Molecular biology Phosphoric Monoester Hydrolases Bicarbonates Chemistry Phosphoglycerate Kinase Enzyme chemistry Glycerophosphates Human erythrocytes NAD+ kinase |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - General Subjects. 158:317-328 |
| ISSN: | 0304-4165 |
| DOI: | 10.1016/0304-4165(68)90285-7 |
| Popis: | The synthesis of 2,3-P2-glycerate in hemolysates of erythrocytes previously depleted by 50% of the ester was dependent on substrates and regulators of the phosphoglycerate cycle. Glyceraldehyde-3-P, NAD+ and P1 stimulated synthesis of 2,3-P2-glycerate. 3-P-glycerate increased synthesis of 2,3-P2-glycerate by stimulating diphosphoglycerate mutase (EC 2.7.5.4) and not by reaction with phosphoglycerate kinase (EC 2.7.2.3), as physiological levels of ATP (1 mM) did not increase diphosphoglycerate synthesis. Pyruvate and bicarbonate also stimulated synthesis. The pH optimum for synthesis from glyceraldehyde-3-P was 8.2. ADP and AMP reduced the synthesis of 2,3-P2-glycerate from glyceraldehyde-3-P and produced quantities of lactate equivalent to he change in 2,3-P2-glycerate. Diphosphoglycerate phosphatase (EC 3.1.3.13) was inactive in the hemolysates but could be activated with NaHSO3. The enzyme was weakly active in fresh erythrocytes and did not become activated during storage of erythrocytes for 2 weeks at 4°. Simultaneously, the rate of synthesis of 2,3-P2-glycerate fell progressively to 50%. Extracts of stored erythrocytes in which ADP and AMP increased with storage time increasingly inhibited the synthesis of 2,3-P2-glycerate by hemolysates of fresh erythrocytes. The data suggest that the decline in amounts of 2,3-P2-glycerate in erythrocytes stored at 4° is due to a significant extent to a reduction in rate of synthesis. This is due in part to an accumulation of adenine nucleotides. |
| Databáze: | OpenAIRE |
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