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61.
Activators of yeast hexokinase 总被引:8,自引:0,他引:8
62.
Histamine formation in rat brain during development 总被引:9,自引:7,他引:2
J C Schwartz C Lampart C Rose M C Rehault S Bischoff H Pollard 《Journal of neurochemistry》1971,18(9):1787-1789
63.
Mary Callaghan Rose Robert W. Henkens 《Biochimica et Biophysica Acta (BBA)/General Subjects》1974,372(2):426-435
Stability constants of sodium and potassium complexes of valinomycin in some alcohols and water—organic solvent mixtures have been determined by titration, using circular dichroism to monitor complex formation. Constants range from 101 to 106 M−1. Stability of the potassium and sodium complexes increases with decreasing dielectric constant, but the ratio of the constants remains about 103–104. As others have shown, a similar selectivity for K+ is observed in a number of other types of measurements involving valinomycin. These include the permeability and conductance ratios which characterize the selectivity of cation transport through membranes and the ratio of salt extraction equilibrium constants. On the basis of data presented here, and elsewhere, it is suggested that conformational constraints within the depsipeptide part of the complexes aid ion selectivity and that differences in cation solvation and carbonyl ligand binding energies make an important, roughly equal, contribution. 相似文献
64.
Herbert M. Schulman Jaime Martinez-Medellin Rose Sidloi 《Biochimica et Biophysica Acta (BBA)/General Subjects》1974,343(3):529-534
The effect of three groups of metabolic inhibitors on the incorporation of Fe and release of bicarbonate from transferrin by rabbit reticulocytes was measured. Inhibitors which affect reticulocyte Fe and transferrin uptake to the same extent (sodium arsenite, N-ethylmaleimide and iodoacetamide); those which inhibit reticulocyte Fe uptake to a greater extent than transferrin uptake (NaN3, NaF, NaCN, rotenone, oligomycin, 2,4-dinitrophenol and cycloheximide); and compounds which after reticulocyte heme synthesis (CoCl2, isonicotinic acid hydrazide and hemin) were used. In each case the effect on Fe incorporation and bicarbonate release was the sameThus, additional evidence has been obtained for the idea that the reticulocyte-mediated release of Fe and bicarbonate from transferrin are tightly coupled. The results are consistent with the hypothesis that an enzymatic attack on transferrin-bound bicarbonate is involved in the removal of Fe from transferrin by erythroid cells. 相似文献
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The distribution of glucose and [14C]glucose between erythrocytes and plasma in the rat 总被引:5,自引:4,他引:1 下载免费PDF全文
1. Of the glucose in rat blood 79.8+/-3.3% (s.d.) was in the plasma. The variance was mostly due to differences between rats. 2. The concentration of glucose in erythrocyte water was 51+/-8% (s.d.) of that in plasma water. 3. The ratio (specific radioactivity in plasma)/(specific radioactivity in whole blood), i.e. the P/B ratio, was estimated for glucose at intervals after intravenous injection of [U-(14)C]glucose and [U-(14)C]fructose. The ratio differed from unity by more than the standard error of a single determination of the specific radioactivity of blood or plasma glucose except from 10 to 17min. after injection of [(14)C]glucose and from 22 to 30min. after injection of [(14)C]fructose. At all other times specific radioactivities in blood had to be corrected to give specific radioactivities in plasma. How to do so is described. 4. The P/B ratios were accounted for by a turnover of glucose in erythrocytes of 0.14mumole/min./ml. of erythrocytes. 5. Metabolism of glucose in rat erythrocytes is unlikely to be a major source of lactate. 相似文献
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