THE PENTOSE PHOSPHATE METABOLIC PATHWAY IN THE HUMAN ERYTHROCYTE: I. THE TRANSFORMATION OF RIBOSE-5-PHOSPHATE TO KETOPENTOSE-5-PHOSPHATE

1961 ◽  
Vol 39 (3) ◽  
pp. 527-532 ◽  
Author(s):  
Y. S. Brownstone ◽  
O. F. Denstedt
Keyword(s):  
Metabolic Pathway ◽  
Human Erythrocyte ◽  
Pentose Phosphate ◽  
Red Cell

Ribose-5-phosphate is converted to ketopentose-5-phosphate by red cell hemolyzate at the rate of 3.6 mmoles/g Hb/hour at 37 °C. The rate of activity of the enzymes remains fairly steady over a broad range of pH (6.5 to 9.0).

THE METABOLISM OF THE ERYTHROCYTE: XIV. METABOLISM OF NUCLEOSIDES BY THE ERYTHROCYTE

1956 ◽  
Vol 34 (5) ◽  
pp. 927-937 ◽  
Author(s):  
David Rubinstein ◽  
Orville F. Denstedt
Keyword(s):  
Blood Cell ◽  
Experimental Evidence ◽  
Adenosine Deaminase ◽  
Red Blood Cell ◽  
Metabolic Pathway ◽  
Pentose Phosphate ◽  
Organic Phosphate ◽  
Phosphate Esters ◽  
Red Cell ◽  
Rate Limiting

Adenosine, added to blood, undergoes deamination in the red cells with the formation of inosine. The latter undergoes phosphorolysis to yield hypoxanthine and presumably ribose-1-phosphate. The pentose phosphate is metabolized to lactate yielding ATP in the process. The adenosine deaminase and the purine riboside phosphorylase of the red cell occur in the stroma-free hemolyzate. No adenine is formed from adenosine in the blood, nor is adenine metabolized by the erythrocyte. Xanthosine, guanosine, and inosine, added to blood, follow the same metabolic pathway as adenosine and their metabolism brings about a comparable degree of resynthesis of ATP and other organic phosphate esters and formation of lactate. The experimental evidence indicates that the phosphorolysis of the nucleoside is not the rate-limiting reaction in the metabolism of these compounds in the red blood cell.

THE METABOLISM OF THE ERYTHROCYTE: XIV. METABOLISM OF NUCLEOSIDES BY THE ERYTHROCYTE

1956 ◽  
Vol 34 (1) ◽  
pp. 927-937 ◽  
Author(s):  
David Rubinstein ◽  
Orville F. Denstedt
Keyword(s):  
Blood Cell ◽  
Experimental Evidence ◽  
Adenosine Deaminase ◽  
Red Blood Cell ◽  
Metabolic Pathway ◽  
Pentose Phosphate ◽  
Organic Phosphate ◽  
Phosphate Esters ◽  
Red Cell ◽  
Rate Limiting

Adenosine, added to blood, undergoes deamination in the red cells with the formation of inosine. The latter undergoes phosphorolysis to yield hypoxanthine and presumably ribose-1-phosphate. The pentose phosphate is metabolized to lactate yielding ATP in the process. The adenosine deaminase and the purine riboside phosphorylase of the red cell occur in the stroma-free hemolyzate. No adenine is formed from adenosine in the blood, nor is adenine metabolized by the erythrocyte. Xanthosine, guanosine, and inosine, added to blood, follow the same metabolic pathway as adenosine and their metabolism brings about a comparable degree of resynthesis of ATP and other organic phosphate esters and formation of lactate. The experimental evidence indicates that the phosphorolysis of the nucleoside is not the rate-limiting reaction in the metabolism of these compounds in the red blood cell.

THE PENTOSE PHOSPHATE METABOLIC PATHWAY IN THE HUMAN ERYTHROCYTE: III. THE STABILITY OF THE PENTOSE PHOSPHATE METABOLIC SYSTEM IN PRESERVED ERYTHROCYTES

1961 ◽  
Vol 39 (3) ◽  
pp. 545-550 ◽  
Author(s):  
Y. S. Brownstone ◽  
O. F. Denstedt
Keyword(s):  
Metabolic Pathway ◽  
Human Erythrocyte ◽  
Pentose Phosphate ◽  
Red Cells ◽  
Prolonged Storage ◽  
Metabolic System ◽  
The Stability ◽  
Citrate Dextrose ◽  
Human Red Cells

The activity of the enzymes of the pentose phosphate metabolic pathway in the dialyzed stroma-free hemolyzate (SFH) from human red cells remains unaltered after prolonged storage of the blood in acidified citrate dextrose (ACD) medium at 4 °C.Erythrocytes from children with galactosemia were found to have normal transketolase and transaldolase activity.

scholarly journals Red cell proteins. I. Two-dimensional mapping of human erythrocyte lysate proteins

Blood ◽  
1979 ◽  
Vol 53 (6) ◽  
pp. 1121-1132 ◽  
Author(s):  
JJ Edwards ◽  
NG Anderson ◽  
SL Nance ◽  
NL Anderson
Keyword(s):  
Human Erythrocyte ◽  
Sodium Dodecyl ◽  
Deae Cellulose ◽  
Cell Protein ◽  
Red Cell ◽  
Two Dimensional ◽  
Two Dimensional Electrophoresis ◽  
Mapping Techniques ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Dimensional Electrophoresis

Abstract Human erythrocyte lysate proteins were resolved into over 250 discrete spots by two-dimensional electrophoresis using isoelectric focusing in the first dimension and electrophoresis in the presence of sodium dodecyl sulfate, (SDS) in the second. The overwhelming excess of hemoglobin has made such analyses difficult in the past. However, with the ISO-DALT two-dimensional electrophoresis system, large numbers of red cell proteins can be mapped in the presence of hemoglobin. When hemoglobin and several other major proteins are removed by adsorption to DEAE-cellulose, additional minor components are seen, giving a total of over 275. With the use of purified preparations, the map positions of five cell enzymes or their subunits were determined: pyruvate kinase, catalase, glucose-6-phosphate dehydrogenase, hypoxanthine phosphoribosyltransferase, and carbonic anhydrase. The mapping techniques described complement and extend those traditionally used to find human red cell protein variants.

scholarly journals Regulatory Mechanism of Glutathione Reductase Activity in Human Red Cells

Blood ◽  
1974 ◽  
Vol 43 (1) ◽  
pp. 99-109 ◽  
Author(s):  
Yoshihito Yawata ◽  
Kouichi R. Tanaka
Keyword(s):  
Glutathione Reductase ◽  
Hepatic Cirrhosis ◽  
Reductase Activity ◽  
Pentose Phosphate ◽  
Red Cells ◽  
Clinical Severity ◽  
Red Cell ◽  
Metabolic Pattern ◽  
Chronic Uremia ◽  
Glutathione Reductase Activity

Abstract The mechanism by which glutathione reductase (GR) activity is regulated in relation to flavin metabolism was studied in red cells of normal adults, cord blood, and patients with severe metabolic disorders using spectrophotometric, fluorometric, and radiochemical methods. The increased activity of GR in red cells of adult patients with severe hepatic cirrhosis, chronic uremia, and glucose-6-phosphate dehydrogenase (G-6-PD) deficiency is related to the increased per cent saturation of GR with flavin adenine dinucleotide (FAD), and increased red cell flavin level. The per cent saturation of GR with FAD correlates with (1) the degree of clinical severity in hepatic cirrhosis or chronic uremia, and (2) total flavin level in red cells. Thus, the increased GR activity in these patients may be regulated actively or passively by the increased flavin level in red cells. This suggests that the increased requirement for enhanced activity of the pentose phosphate pathway may affect GR metabolism secondarily, leading to the association of GR with FAD through an increased uptake of riboflavin. In contrast to the results in adult red cells, cord erythrocytes show an unexpected metabolic pattern of GR and flavin metabolism. Although the total GR activity of cord red cells is considerably higher than in adult red cells, cord red cell GR is only partly saturated with FAD even in the presence of a significantly increased flavin level in cord red cells. Thus, cord red cells may have an additional control mechanism of GR activity.

scholarly journals Metabolic dependence of protein arrangement in human erythrocyte membranes. I. Analysis of spectrin-rich complexes in ATP-depleted red cells

Blood ◽  
1978 ◽  
Vol 51 (3) ◽  
pp. 385-395 ◽  
Author(s):  
J Palek ◽  
SC Liu ◽  
LM Snyder
Keyword(s):  
Human Erythrocyte ◽  
Polyacrylamide Gel Electrophoresis ◽  
Band 3 ◽  
Atp Depletion ◽  
Red Cells ◽  
Erythrocyte Membranes ◽  
Red Cell ◽  
Aerobic Conditions ◽  
Spontaneous Formation ◽  
Human Erythrocyte Membranes

Abstract The discocyte-echinocyte transformation and the decrease in deformability associated with red cell ATP depletion have been attributed to changes in the physical properties of spectrin and actin, membrane proteins located at the membrane-cytosol interface. We investigated the spontaneous formation of spectrin-rich complexes in human erythrocyte membranes, employing two-dimensional SDS- polyacrylamide gel electrophoresis. Membranes of red cells depleted in ATP under aerobic conditions exhibited (1) an increase in components 4.5 and 8 and globin subunits, (2) a spontaneous formation of heterodimers of spectrin 1 + 2 and spectrin 2 + component 4.9, and (3) a large molecular weight (greater than 10(6) daltons) protein complex with a high spectrin to band 3 ratio. These complexes were dissociated with dithiothreitol and were prevented by anaerobic incubation or the maintenance of red cell ATP and GSH levels with glucose, adenine, and inosine. The complexes 1 + 2 and 2 + 4.9 were also seen in acetylphenylhydrazine-treated, glucose-6-phosphate dehydrogenase- deficient fresh erythrocytes that showed marked GSH depletion but preserved greater than 70% of the original ATP level. However, membranes of these cells did not contain the greater 10(6) dalton aggregate with a high spectrin to band 3 ratio. We concluded that the formation of the latter complex results from rearrangement of spectrin and other polypeptides in membranes of ATP-depleted red cells. Under aerobic conditions, the rearranged proteins undergo spontaneous intermolecular crosslinkings through disulfide couplings.

THE PENTOSE PHOSPHATE METABOLIC PATHWAY IN THE HUMAN ERYTHROCYTE: II. THE TRANSKETOLASE AND TRANSALDOLASE ACTIVITY OF THE HUMAN ERYTHROCYTE

1961 ◽  
Vol 39 (3) ◽  
pp. 533-543 ◽  
Author(s):  
Y. S. Brownstone ◽  
O. F. Denstedt
Keyword(s):  
Human Erythrocyte ◽  
Soluble Fraction ◽  
Pentose Phosphate ◽  
Ion Concentration ◽  
Thiamine Pyrophosphate ◽  
Magnesium Ions ◽  
Michaelis Constant ◽  
Hydrogen Ion Concentration ◽  
Wide Range ◽  
Human Red Cells

Transketolase, in the human erythrocyte, is confined to the soluble fraction of the cell. The activation energy for the formation of sedoheptulose-7-phosphate (S-7-P) from pentose phosphate was found to be 11,500 calories and the rate of formation of S-7-P to be directly proportional to the concentration of the enzyme. The Michaelis constant, with ribose-5-phosphate (R-5-P) as the added substrate, was found to be 6 × 10−3 M. The activity of the enzyme is close to the maximum over a wide range of hydrogen ion concentration (pH 7.1 to 8.3) with only a gradual decrease beyond these limits. The transketolase, in the dialyzed stroma-free hemolyzate, is active without the addition of magnesium ions or thiamine pyrophosphate. It is unaffected by sulphydryl-binding inhibitors and by EDTA and oxythiamine pyrophosphate.Transaldolase activity also has been demonstrated in the hemolyzate of human red cells. The rate of the production of hexose phosphate from sedoheptulose-7-phosphate was found to be of the order of 40 μmoles/g Hb/hour. The activity of the enzyme is close to the maximum between pH 7.18 and 7.75.

scholarly journals THE DEVELOPMENT OF LEISHMANIA DONOVANI IN VITRO AT 37°C

1953 ◽  
Vol 97 (2) ◽  
pp. 177-188 ◽  
Author(s):  
William Trager
Keyword(s):  
Human Serum ◽  
Human Erythrocyte ◽  
Small Proportion ◽  
Culture Medium ◽  
Leishmania Donovani ◽  
Cell Extract ◽  
Rabbit Serum ◽  
Red Cell

Suspensions of leishmanias from the spleen of hamsters infected with Leishmania donovani were placed in culture flasks and incubated at 37°C. In a medium of human erythrocyte extract and human serum there appeared within a day or two aflagellate forms resembling leishmanias but larger, as well as other aflagellate forms more nearly resembling rounded leptomonads. These intermediate forms multiplied during the first 4 days of culture. They then slowly died off, despite frequent renewal of the culture medium. Sometimes a small proportion of motile, typical leptomonads also appeared in such cultures. Leptomonads from cultures maintained at 28°C., when placed in the human red cell extract-human serum medium and incubated at 37°C., survived at least 4 days. For both types of effect, human serum could be replaced by normal hamster serum but not by rabbit serum. Nicotinamide, added to the human red cell extract-human serum medium at a concentration of 400 mg. per 100 ml., completely prevented the development of intermediate forms from leishmanias and brought about the rapid death of leptomonads at 37°C.

scholarly journals Red cell proteins. I. Two-dimensional mapping of human erythrocyte lysate proteins

Blood ◽  
1979 ◽  
Vol 53 (6) ◽  
pp. 1121-1132
Author(s):  
JJ Edwards ◽  
NG Anderson ◽  
SL Nance ◽  
NL Anderson
Keyword(s):  
Human Erythrocyte ◽  
Sodium Dodecyl ◽  
Deae Cellulose ◽  
Cell Protein ◽  
Red Cell ◽  
Two Dimensional ◽  
Two Dimensional Electrophoresis ◽  
Mapping Techniques ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Dimensional Electrophoresis

Human erythrocyte lysate proteins were resolved into over 250 discrete spots by two-dimensional electrophoresis using isoelectric focusing in the first dimension and electrophoresis in the presence of sodium dodecyl sulfate, (SDS) in the second. The overwhelming excess of hemoglobin has made such analyses difficult in the past. However, with the ISO-DALT two-dimensional electrophoresis system, large numbers of red cell proteins can be mapped in the presence of hemoglobin. When hemoglobin and several other major proteins are removed by adsorption to DEAE-cellulose, additional minor components are seen, giving a total of over 275. With the use of purified preparations, the map positions of five cell enzymes or their subunits were determined: pyruvate kinase, catalase, glucose-6-phosphate dehydrogenase, hypoxanthine phosphoribosyltransferase, and carbonic anhydrase. The mapping techniques described complement and extend those traditionally used to find human red cell protein variants.

RED CELL METABOLISM IN THE PREMATURE INFANT

PEDIATRICS ◽  
1967 ◽  
Vol 39 (5) ◽  
pp. 689-695
Author(s):  
Frank A. Oski
Keyword(s):  
Premature Infants ◽  
Pentose Phosphate Pathway ◽  
Cell Metabolism ◽  
Glucose Consumption ◽  
Pentose Phosphate ◽  
Red Cells ◽  
Red Cell ◽  
O2 Production ◽  
Cell Glucose ◽  
Normal Adults

Red cell glucose consumption and C14 O2 production from glucose-I-C14 and glucose-U-C14 were measured in 17 premature infants, 15 normal adults and 7 patients with reticulocytosis. The red cells from the premature infants consumed significantly more glucose and produced more C14 O2 than did the cells from normal adults but did not differ in this regard from patients with elevated reticulocyte counts. The percent of glucose metabolized by the pentose phosphate pathway in the red cells of the infants was as great, and often greater, than that observed in the other two groups. The red cells of the premature infants also demonstrated an ability to respond to methylene blue. The pentose phosphate pathway would appear to be intact in the red cells from these infants and inadequate generation of NADPH2 is not responsible for the ease with which these cells develop oxidative denaturation of hemoglobin.

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