scholarly journals Erythrocyte transketolase activity and the percentage stimulation by thiamin pyrophosphate as criteria of thiamin status in the pig

1973 ◽  
Vol 30 (03) ◽  
pp. 391 ◽  
Author(s):  
C. L. Peng ◽  
H. Heitman
Keyword(s):  
Transketolase Activity ◽  
Thiamin Pyrophosphate

scholarly journals Three Case Reports to Illustrate Clinical Applications in the Use of Erythrocyte Transketolase

2007 ◽  
Vol 4 (2) ◽  
pp. 247-250 ◽  
Author(s):  
Derrick Lonsdale
Keyword(s):  
Clinical Setting ◽  
Case Reports ◽  
Clinical Applications ◽  
Therapeutic Use ◽  
Transketolase Activity ◽  
Thiamin Pyrophosphate ◽  
Cofactor Deficiency

Non-caloric nutrients (NCN) are extremely numerous and it is more than obvious that they work in a team relationship. These vitally important interactions are, for the most part, poorly understood. These brief case reports illustrate this in the therapeutic use of thiamin in a clinical setting. The initially abnormal erythrocyte transketolase activity (TKA) and/or the thiamin pyrophosphate effect (TPPE), indicating intracellular cofactor deficiency, usually improves with thiamin administration. Biochemical correction of the abnormality is, however, invariably dependent on the provision of other NCN, especially magnesium. In two patients reported here, this correction required several infusions containing magnesium and other NCN administered intravenously. In a third patient, hemoconcentration associated with an abnormal TPPE was normalized after administration of nutrients that included thiamin and magnesium.

Improved determination of transketolase activity in erythrocytes.

1984 ◽  
Vol 30 (5) ◽  
pp. 658-661 ◽  
Author(s):  
T Takeuchi ◽  
K Nishino ◽  
Y Itokawa
Keyword(s):  
Human Erythrocytes ◽  
Thiamin Deficiency ◽  
Transketolase Activity ◽  
Thiamin Pyrophosphate

Abstract We describe a new and better method for determining transketolase (EC 2.2.1.1) activity in human erythrocytes. Heating the hemolysate (55 degrees C, 5 min) inactivates transaldolase (EC 2.2.1.2), the enzyme that catalyzes the formation of fructose 6-phosphate and erythrose 4-phosphate from sedoheptulose 7-phosphate and glyceraldehyde 3-phosphate. The net effect is that the quantity of sedoheptulose 7-phosphate formed more precisely represents the transketolase activity, which is unaffected under these conditions. Use of ribosephosphate isomerase (EC 5.3.1.6) and ribulose-phosphate 3-epimerase (EC 5.1.3.1) to establish an equilibrium among the pentoses allowed us to confirm the stoichiometry of the transketolase reaction. We also discuss the effect of thiamin pyrophosphate, which is used to reflect thiamin deficiency.

Erythrocyte transketolase activity in uremia

1980 ◽  
Vol 108 (2) ◽  
pp. 169-177 ◽  
Author(s):  
Kuriyama Masaru ◽  
Mizuma Atsumi ◽  
Yokomine Ryoko ◽  
Igata Akihiro ◽  
Otuji Yoshito
Keyword(s):  
Transketolase Activity

scholarly journals The biosynthesis of valine from isobutyrate by Peptostreptococcus elsdenii and Bacteroides ruminicola

1971 ◽  
Vol 121 (3) ◽  
pp. 431-437 ◽  
Author(s):  
Milton J. Allison ◽  
J. L. Peel
Keyword(s):  
Molecular Hydrogen ◽  
Photosynthetic Bacteria ◽  
Deae Cellulose ◽  
Cell Protein ◽  
Acetyl Phosphate ◽  
Acid Fraction ◽  
Benzyl Viologen ◽  
Electron Carrier ◽  
Thiamin Pyrophosphate ◽  
Reductive Carboxylation

1. Growing cultures of Peptostreptococcus elsdenii and Bacteroides ruminicola incorporate 14C from [1-14C]isobutyrate into the valine of cell protein. With P. elsdenii some of the 14C is also incorporated into leucine. 2. Crude cell-free extracts of both organisms in the presence of glutamine, carbon dioxide and suitable sources of energy and electrons incorporate 14C from [1-14C]isobutyrate into valine but not into leucine. 3. With extracts of P. elsdenii treated with DEAE-cellulose the reaction is dependent on ATP, CoA, thiamin pyrophosphate, molecular hydrogen and a low-potential electron carrier (ferredoxin, flavodoxin or benzyl viologen). 4. The same extracts incorporate 14C from NaH14CO3 into valine in the presence of isobutyrate plus ATP, CoA, glutamine and ferredoxin; isobutyryl-CoA or isobutyryl phosphate plus CoA will replace the isobutyrate plus CoA and ATP. With acetyl phosphate in place of isobutyryl phosphate, 14C is incorporated into alanine. With isovalerate or 2-methylbutyrate in place of isobutyrate, 14C is incorporated into leucine and isoleucine respectively. 5. When carrier 2-oxoisovalerate is added to the carboxylating system 14C from [1-14C]isobutyrate passes into the oxo acid fraction. 6. It is concluded that these two organisms form valine from isobutyrate by the sequence isobutyrate→isobutyryl-CoA→2-oxoisovalerate→valine and that the reductive carboxylation of isobutyrate is catalysed by a system similar to the pyruvate synthetase of clostridia and photosynthetic bacteria.

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