scholarly journals Correction: The Secreted Triose Phosphate Isomerase of Brugia malayi Is Required to Sustain Microfilaria Production In Vivo

2014 ◽  
Vol 10 (4) ◽  
pp. e1004133 ◽  
Author(s):  
Keyword(s):  
Brugia Malayi ◽  
Triose Phosphate Isomerase ◽  
Triose Phosphate

scholarly journals The Secreted Triose Phosphate Isomerase of Brugia malayi Is Required to Sustain Microfilaria Production In Vivo

2014 ◽  
Vol 10 (2) ◽  
pp. e1003930 ◽  
Author(s):  
James P. Hewitson ◽  
Dominik Rückerl ◽  
Yvonne Harcus ◽  
Janice Murray ◽  
Lauren M. Webb ◽  
...  
Keyword(s):  
Brugia Malayi ◽  
Triose Phosphate Isomerase ◽  
Triose Phosphate

scholarly journals Mode of action of α-chlorohydrin as a male anti-fertility agent. Inhibition of the metabolism of ram spermatozoa by α-chlorohydrin and location of block in glycolysis

1978 ◽  
Vol 170 (1) ◽  
pp. 23-37 ◽  
Author(s):  
Patricia D. C. Brown-Woodman ◽  
Hideo Mohri ◽  
Toshiko Mohri ◽  
Dai Suter ◽  
Ian G. White
Keyword(s):  
Dehydrogenase Activity ◽  
Recovery Period ◽  
Triose Phosphate Isomerase ◽  
Glycolytic Enzymes ◽  
Unexpected Finding ◽  
Glycolytic Intermediate ◽  
Enzyme Preparations ◽  
Triose Phosphate

1. The effect of α-chlorohydrin on the metabolism of glycolytic and tricarboxylate-cycle substrates by ram spermatozoa was investigated. The utilization and oxidation of fructose and triose phosphate were much more sensitive to inhibition by α-chlorohydrin (0.1–1.0mm) than lactate or pyruvate. Inhibition of glycolysis by α-chlorohydrin is concluded to be between triose phosphate and pyruvate formation. Oxidation of glycerol was not as severely inhibited as that of the triose phosphate. This unexpected finding can be explained in terms of competition between glycerol and α-chlorohydrin. A second, much less sensitive site, of α-chlorohydrin inhibition appears to be associated with production of acetyl-CoA from exogenous and endogenous fatty acids. 2. Measurement of the glycolytic intermediates after incubation of spermatozoal suspensions with 15mm-fructose in the presence of 3mm-α-chlorohydrin showed a ‘block’ in the conversion of glyceraldehyde 3-phosphate into 3-phosphoglycerate. α-Chlorohydrin also caused conversion of most of the ATP in spermatozoa into AMP. After incubation with 3mm-α-chlorohydrin, glyceraldehyde 3-phosphate dehydrogenase and triose phosphate isomerase activities were decreased by approx. 90% and 80% respectively, and in some experiments aldolase was also inhibited. Other glycolytic enzymes were not affected by a low concentration (0.3mm) of α-chlorohydrin. Loss of motility of spermatozoa paralleled the decrease in glyceraldehyde 3-phosphate dehydrogenase activity. α-Chlorohydrin, however, did not inhibit glyceraldehyde 3-phosphate dehydrogenase or triose phosphate isomerase in sonicated enzyme preparations when added to the assay cuvette. 3. Measurement of intermediates and glycolytic enzymes in ejaculated spermatozoa before, during and after injection of rams with α-chlorohydrin (25mg/kg body wt.) confirmed a severe block in glycolysis in vivo at the site of triose phosphate conversion into 3-phosphoglycerate within 24h of the first injection. Glyceraldehyde 3-phosphate dehydrogenase activity was no longer detectable and both aldolase and triose phosphate isomerase were severely inhibited. Spermatozoal ATP decreased by 92% at this time, being quantitatively converted into AMP. At 1 month after injection of α-chlorohydrin glycolytic intermediate concentrations returned to normal in the spermatozoa but ATP was still only 38% of the pre-injection concentration. Motility of spermatozoa was, however, as good as during the pre-injection period. The activity of the inhibited enzymes also returned to normal during the recovery period and 26 days after injection were close to pre-injection values. 4. An unknown metabolic product of α-chlorohydrin is suggested to inhibit glyceraldehyde 3-phosphate dehydrogenase and triose phosphate isomerase of spermatozoa. This results in a lower ATP content, motility and fertility of the spermatozoa. Glycidol was shown not to be an active intermediate of α-chlorohydrin in vitro.

scholarly journals A model study of the fructose diphosphatase–phosphofructokinase substrate cycle

1973 ◽  
Vol 134 (2) ◽  
pp. 581-586 ◽  
Author(s):  
David P. Bloxham ◽  
Michael G. Clark ◽  
Paul C. Holland ◽  
Henry A. Lardy
Keyword(s):  
Triose Phosphate Isomerase ◽  
Theoretical Treatment ◽  
Glucose Phosphate Isomerase ◽  
Triose Phosphate ◽  
Glucose Phosphate ◽  
Model Study

A fructose diphosphatase–phosphofructokinase substrate cycle has been reconstructed in vitro to provide a system that recycles fructose 6-phosphate and hydrolyses ATP to ADP and Pi. The concerted actions of glucose phosphate isomerase, phosphofructokinase, aldolase and triose phosphate isomerase catalysed the loss of 3H from [5-3H,U-14C]glucose 6-phosphate. This was used as the basis of a method for the estimation of the fructose diphosphatase–phosphofructokinase substrate cycle. For the reconstructed cycle, the rate of decrease of the 3H/14C ratio in [5-3H,U-14C]hexose 6-phosphate was proportional to the rate of fructose 6-phosphate substrate cycling. A detailed theoretical treatment of this relationship is developed, which enables the rate of substrate cycling to be determined in vivo.

scholarly journals Disequilibrium in the triose phosphate isomerase system in rat liver

1969 ◽  
Vol 115 (4) ◽  
pp. 837-842 ◽  
Author(s):  
R. L. Veech ◽  
L. Raijman ◽  
K. Dalziel ◽  
H. A. Krebs
Keyword(s):  
Rat Liver ◽  
Significant Proportion ◽  
Enzyme Concentration ◽  
Triose Phosphate Isomerase ◽  
Distribution Data ◽  
Dihydroxyacetone Phosphate ◽  
Triose Phosphate ◽  
High Enzyme Concentration ◽  
Resting Muscle

1. The equilibrium constant at 38° and I 0·25 of the triose phosphate isomerase reaction was found to be 22·0 and that of the aldolase reaction, 0·99×10−4m. The [dihydroxyacetone phosphate]/[glyceraldehyde phosphate] ratio was found to be 9·3 in rat liver. The causes of the apparent deviation of the triose phosphate isomerase system from equilibrium in vivo have been investigated. 2. The equilibria of the triose phosphate isomerase and aldolase reactions were studied with relatively large concentrations of crystalline enzymes and small concentrations of substrates, approximating to those found in rat liver and muscle. There was significant binding of fructose diphosphate by aldolase under these conditions. There was no evidence that binding of glyceraldehyde phosphate by either enzyme affected the equilibria. 3. The deviation from equilibrium of the triose phosphate isomerase system in rat liver can be accounted for by the low activity of the enzyme, in relation to the flux, at low physiological concentrations of glyceraldehyde phosphate (about 3μm). It has been calculated that a flux of 1·8μmoles/min./g. wet weight of liver would be expected to cause the measured degree of disequilibrium found in vivo. 4. The conclusion that the triose phosphate isomerase is not at equilibrium is in accordance with the situation postulated by Rose, Kellermeyer, Stjernholm & Wood (1962) on the basis of isotope-distribution data. 5. The triose phosphate isomerase system is closer to equilibrium in resting muscle probably because of a very low flux and a high enzyme concentration. 6. The aldolase system deviated from equilibrium in rat liver by a factor of about 10 and by a much greater factor in resting muscle. 7. The measurement of total dihydroxyacetone phosphate and glyceraldehyde phosphate content indicates the concentrations of the free metabolites in the tissue. This may not hold for fructose diphosphate, a significant proportion of which may be bound to aldolase.

scholarly journals A High-Content Screening Assay for Small Molecules That Stabilize Mutant Triose Phosphate Isomerase (TPI) as Treatments for TPI Deficiency

2021 ◽  
pp. 247255522110181
Author(s):  
Andreas Vogt ◽  
Samantha L. Eicher ◽  
Tracey D. Myers ◽  
Stacy L. Hrizo ◽  
Laura L. Vollmer ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Large Scale ◽  
Protein Quality ◽  
Fluorescent Protein ◽  
Triose Phosphate Isomerase ◽  
Pharmacological Intervention ◽  
Screening Assay ◽  
Triose Phosphate ◽  
The Common ◽  
Green Fluorescent

Triose phosphate isomerase deficiency (TPI Df) is an untreatable, childhood-onset glycolytic enzymopathy. Patients typically present with frequent infections, anemia, and muscle weakness that quickly progresses with severe neuromusclar dysfunction requiring aided mobility and often respiratory support. Life expectancy after diagnosis is typically ~5 years. There are several described pathogenic mutations that encode functional proteins; however, these proteins, which include the protein resulting from the “common” TPIE105D mutation, are unstable due to active degradation by protein quality control (PQC) pathways. Previous work has shown that elevating mutant TPI levels by genetic or pharmacological intervention can ameliorate symptoms of TPI Df in fruit flies. To identify compounds that increase levels of mutant TPI, we have developed a human embryonic kidney (HEK) stable knock-in model expressing the common TPI Df protein fused with green fluorescent protein (HEK TPIE105D-GFP). To directly address the need for lead TPI Df therapeutics, these cells were developed into an optical drug discovery platform that was implemented for high-throughput screening (HTS) and validated in 3-day variability tests, meeting HTS standards. We initially used this assay to screen the 446-member National Institutes of Health (NIH) Clinical Collection and validated two of the hits in dose–response, by limited structure–activity relationship studies with a small number of analogs, and in an orthogonal, non-optical assay in patient fibroblasts. The data form the basis for a large-scale phenotypic screening effort to discover compounds that stabilize TPI as treatments for this devastating childhood disease.

scholarly journals Triose Phosphate Isomerase from Bakers' Yeast

1972 ◽  
Vol 247 (10) ◽  
pp. 3361-3362
Author(s):  
Stuart W. Hawkinson ◽  
Chin Hsuan Wei ◽  
Fred C. Hartman ◽  
I. Lucille Norton ◽  
J. Ralph Einstein
Keyword(s):  
Triose Phosphate Isomerase ◽  
Triose Phosphate

PRENATAL DIAGNOSIS OF TRIOSE PHOSPHATE ISOMERASE DEFICIENCY

The Lancet ◽  
1989 ◽  
Vol 334 (8667) ◽  
pp. 871 ◽  
Author(s):  
B. Dallapiccola ◽  
G. Novelli
Keyword(s):  
Prenatal Diagnosis ◽  
Triose Phosphate Isomerase ◽  
Triose Phosphate
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