scholarly journals Relationships between concentration of hepatic intermediary metabolites and induction of the key glycolytic enzymes in vivo

1973 ◽  
Vol 136 (3) ◽  
pp. 455-465 ◽  
Author(s):  
J. M. Gunn ◽  
C. B. Taylor
Keyword(s):  
Pyruvate Kinase ◽  
Time Course ◽  
Adenine Nucleotides ◽  
Metabolite Profile ◽  
Glycolytic Enzymes ◽  
British Library ◽  
Dihydroxyacetone Phosphate ◽  
Intermediary Metabolites ◽  
Metabolite Concentrations

1. The time-course for the induction of hepatic glucokinase, hexokinase, phosphofructokinase, liver-type and muscle-type pyruvate kinases in reponse to various diets and insulin has been investigated over the first 48h of change in both diabetic and non-diabetic rats. 2. The results are consistent with there being separate regulatory mechanisms for the induction of each of the three key enzymes, that is for glucokinase, phosphofructokinase and liver-type pyruvate kinase. 3. To investigate the possibility that induction of these enzymes is mediated through specific metabolites a full metabolite profile has been determined under conditions identical with those in the induction experiments and the results examined for correlations between metabolite concentrations and enzyme activities. 4. Several such relationships were detected and those between glucokinase activity and the phosphorylation state of the adenine nucleotides and between liver-type pyruvate kinase activity and the concentrations of dihydroxyacetone phosphate and pyruvate are discussed in relation to the concept of inducing metabolites. 5. It is suggested that the induction of glycolytic enzymes by insulin may be secondary to the changes in the concentration of specific hepatic metabolites brought about by the acute effects of the hormone. 6. The details of the metabolite concentrations in the various experimental states have been deposited as Supplementary Publication SUP 50021 at the British Library (Lending Division) (formerly the National Lending Library for Science and Technology), Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973), 131, 5.

scholarly journals Targeting Pyruvate Kinase M2 and Lactate Dehydrogenase A Is an Effective Combination Strategy for the Treatment of Pancreatic Cancer

Cancers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1372 ◽  
Author(s):  
Goran Hamid Mohammad ◽  
Vessela Vassileva ◽  
Pilar Acedo ◽  
Steven W. M. Olde Damink ◽  
Massimo Malago ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cell Proliferation ◽  
Enzyme Activity ◽  
Lactate Dehydrogenase ◽  
Tumor Growth ◽  
Pyruvate Kinase ◽  
Glycolytic Enzymes ◽  
Pyruvate Kinase M2 ◽  
Tumor Tissues

Reprogrammed glucose metabolism is one of the hallmarks of cancer, and increased expression of key glycolytic enzymes, such as pyruvate kinase M2 (PKM2) and lactate dehydrogenase A (LDHA), has been associated with poor prognosis in various malignancies. Targeting these enzymes could attenuate aerobic glycolysis and inhibit tumor proliferation. We investigated whether the PKM2 activator, TEPP-46, and the LDHA inhibitor, FX-11, can be combined to inhibit in vitro and in vivo tumor growth in preclinical models of pancreatic cancer. We assessed PKM2 and LDHA expression, enzyme activity, and cell proliferation rate after treatment with TEPP-46, FX-11, or a combination of both. Efficacy was validated in vivo by evaluating tumor growth, PK and LDHA activity in plasma and tumors, and PKM2, LDHA, and Ki-67 expression in tumor tissues following treatment. Dual therapy synergistically inhibited pancreatic cancer cell proliferation and significantly delayed tumor growth in vivo without apparent toxicity. Treatment with TEPP-46 and FX-11 resulted in increased PK and reduced LDHA enzyme activity in plasma and tumor tissues and decreased PKM2 and LDHA expression in tumors, which was reflected by a decrease in tumor volume and proliferation. The targeting of glycolytic enzymes such as PKM2 and LDHA represents a promising therapeutic approach for the treatment of pancreatic cancer.

scholarly journals Inhibition of triosephosphate isomerase by phosphoenolpyruvate in the feedback-regulation of glycolysis

Open Biology ◽  
2014 ◽  
Vol 4 (3) ◽  
pp. 130232 ◽  
Author(s):  
Nana-Maria Grüning ◽  
Dijun Du ◽  
Markus A. Keller ◽  
Ben F. Luisi ◽  
Markus Ralser
Keyword(s):  
Oxidative Stress ◽  
Pyruvate Kinase ◽  
Feedback Loop ◽  
Triosephosphate Isomerase ◽  
Feedback Regulation ◽  
Pentose Phosphate ◽  
Yeast Cells ◽  
Dihydroxyacetone Phosphate

The inhibition of triosephosphate isomerase (TPI) in glycolysis by the pyruvate kinase (PK) substrate phosphoenolpyruvate (PEP) results in a newly discovered feedback loop that counters oxidative stress in cancer and actively respiring cells. The mechanism underlying this inhibition is illuminated by the co-crystal structure of TPI with bound PEP at 1.6 Å resolution, and by mutational studies guided by the crystallographic results. PEP is bound to the catalytic pocket of TPI and occludes substrate, which accounts for the observation that PEP competitively inhibits the interconversion of glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. Replacing an isoleucine residue located in the catalytic pocket of TPI with valine or threonine altered binding of substrates and PEP, reducing TPI activity in vitro and in vivo . Confirming a TPI-mediated activation of the pentose phosphate pathway (PPP), transgenic yeast cells expressing these TPI mutations accumulate greater levels of PPP intermediates and have altered stress resistance, mimicking the activation of the PK–TPI feedback loop. These results support a model in which glycolytic regulation requires direct catalytic inhibition of TPI by the pyruvate kinase substrate PEP, mediating a protective metabolic self-reconfiguration of central metabolism under conditions of oxidative stress.

Comparative study of free and bound glycolytic enzymes from sea scorpion brain

1998 ◽  
Vol 76 (4) ◽  
pp. 609-614 ◽  
Author(s):  
Volodymyr I Lushchak ◽  
Ljudmyla P Lushchak ◽  
Tetjana V Bahnjukova ◽  
Alexei V Spichenkov ◽  
Kenneth B Storey
Keyword(s):  
Lactate Dehydrogenase ◽  
Pyruvate Kinase ◽  
Substrate Inhibition ◽  
Physiological Role ◽  
Glycolytic Enzymes ◽  
Free Form ◽  
Hill Coefficients ◽  
Low Ionic Strength ◽  
Scorpaena Porcus

Free and bound forms of hexokinase, pyruvate kinase, and lactate dehydrogenase were prepared from the brain of the sea scorpion (Scorpaena porcus) in a low ionic strength medium. Properties of the free and bound forms were compared to determine whether binding to particulate matter could influence enzyme function or stability in vivo. Changes in pH differently affected the activity of the free and bound forms of all three enzymes. Furthermore, bound forms of hexokinase and pyruvate kinase were more stable than the free enzymes to heating at 45°C. Bound hexokinase showed higher affinity for substrates (ATP, glucose) than the free form and bound lactate dehydrogenase had greater affinity for pyruvate and NADH. Although the affinities of the two forms of pyruvate kinase for substrates were similar, Hill coefficients for phosphoenolpyruvate as well as inhibition by ATP differed between the two enzyme forms. Free and bound lactate dehydrogenase also showed differences in Hill coefficients and bound lactate dehydrogenase was less sensitive to substrate inhibition by high pyruvate concentrations. The possible physiological role of the binding of these glycolytic enzymes to subcellular structures is discussed.Key words: hexokinase, lactate dehydrogenase, pyruvate kinase, enzyme binding, Scorpaena porcus.

A new regulatory principle for in vivo biochemistry: Pleiotropic low affinity regulation by the adenine nucleotides - Illustrated for the glycolytic enzymes ofSaccharomyces cerevisiae

FEBS Letters ◽  
2013 ◽  
Vol 587 (17) ◽  
pp. 2860-2867 ◽  
Author(s):  
Femke I.C. Mensonides ◽  
Barbara M. Bakker ◽  
Frederic Cremazy ◽  
Hanan L. Messiha ◽  
Pedro Mendes ◽  
...  
Keyword(s):  
Adenine Nucleotides ◽  
Glycolytic Enzymes ◽  
Regulatory Principle

Improved metabolite profile smoothing for flux estimation

2015 ◽  
Vol 11 (9) ◽  
pp. 2394-2405 ◽  
Author(s):  
Robert A. Dromms ◽  
Mark P. Styczynski
Keyword(s):  
Time Course ◽  
Metabolite Profile ◽  
Impulse Function ◽  
Metabolite Concentrations ◽  
Time Course Data ◽  
Flux Estimation

We develop several methods to improve the estimation of metabolite concentrations and accumulation fluxes from noisy time-course data, including use of a sigmoidal impulse function and a resampling-based approach.

scholarly journals Decrease in subunit aggregation of phosphoribosylpyrophosphate synthetase: a mechanism for decreased nucleotide concentrations in pyruvate kinase-deficient human erythrocytes

Blood ◽  
1986 ◽  
Vol 68 (5) ◽  
pp. 1024-1029
Author(s):  
CR Zerez ◽  
NA Lachant ◽  
KR Tanaka
Keyword(s):  
Pyruvate Kinase ◽  
Nicotinamide Adenine Dinucleotide ◽  
Adenine Nucleotide ◽  
Adenine Nucleotides ◽  
Gel Permeation Chromatography ◽  
Metabolic Abnormalities ◽  
Gel Permeation ◽  
Reduced Nicotinamide Adenine Dinucleotide

Pyruvate kinase (PK)-deficient RBCs have several unexplained metabolic abnormalities, such as decreased concentrations of total adenine nucleotides (AMP, ADP, and ATP) and total (oxidized and reduced) nicotinamide adenine dinucleotide (NAD). Because 5-phosphoribosyl-1- pyrophosphate (PRPP) is an intermediate in the synthesis of adenine nucleotides and NAD, we investigated PRPP synthetase (PRPPS), the enzyme responsible for PRPP synthesis. This enzyme is regulated, in part, by changes in its state of subunit aggregation. The proportion of aggregated PRPPS can be altered in vitro by ATP and 2,3- diphosphoglycerate (DPG). Because PK-deficient RBCs have decreased ATP and increased DPG concentrations, we examined the state of subunit aggregation of PRPPS in RBCs from normal and PK-deficient subjects, using gel permeation chromatography. Young normal RBCs have more aggregated PRPPS than do older RBCs. In contrast, due to their decreased ATP and increased DPG concentrations, PK-deficient RBCs contain less aggregated PRPPS than do RBCs of comparable age without PK deficiency. These data suggest that PRPPS should be less active in vivo in PK-deficient RBCs. This may play a key role in mediating the decreases in total adenine nucleotide and total NAD concentrations in these RBCs.

Prolonged adenine nucleotide resynthesis and reperfusion injury in postischemic skeletal muscle

1992 ◽  
Vol 262 (5) ◽  
pp. H1538-H1547 ◽  
Author(s):  
B. B. Rubin ◽  
S. Liauw ◽  
J. Tittley ◽  
A. D. Romaschin ◽  
P. M. Walker
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Time Course ◽  
Adenine Nucleotide ◽  
Adenine Nucleotides ◽  
Prolonged Release ◽  
Intracellular Acidosis ◽  
Edema Formation ◽  
Muscle Necrosis

Skeletal muscle ischemia results in energy depletion and intracellular acidosis. Reperfusion is associated with impaired adenine nucleotide resynthesis, edema formation, and myocyte necrosis. The purpose of these studies was to define the time course of cellular injury and adenine nucleotide depletion and resynthesis in postischemic skeletal muscle during prolonged reperfusion in vivo. The isolated canine gracilis muscle model was used. After 5 h of ischemia, muscles were reperfused for either 1 or 48 h. Lactate and creatine phosphokinase (CPK) release during reperfusion was calculated from arteriovenous differences and blood flow. Adenine nucleotides, nucleosides, bases, and creatine phosphate were quantified by high-performance liquid chromatography, and muscle necrosis was assessed by nitroblue tetrazolium staining. Reperfusion resulted in a rapid release of lactate, which paralleled the increase in blood flow, and a delayed but prolonged release of CPK. Edema formation and muscle necrosis increased between 1 and 48 h of reperfusion (P less than 0.05). Recovery of energy stores during reperfusion was related to the extent of postischemic necrosis, which correlated with the extent of nucleotide dephosphorylation during ischemia (r = 0.88, P less than 0.001). These results suggest that both adenine nucleotide resynthesis and myocyte necrosis, which are protracted processes in reperfusing skeletal muscle, are related to the extent of nucleotide dephosphorylation during ischemia.

Decrease in Platelet Adenine Nucleotides Content In Patients With Dic, Thrombosis and After Operation

1979 ◽  
Author(s):  
H. Yamazaki ◽  
T. Motomiya ◽  
N. Miyagawa ◽  
C. Watanabe ◽  
Y. Yahara ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Time Course ◽  
Adenine Nucleotides ◽  
Firefly Luciferase ◽  
Acute Stage ◽  
Platelet Volume ◽  
Recovery Stage ◽  
Release Reaction ◽  
Postoperative State

Conditions which induce platelet release reaction in vivo are not yet obvious. To detect the conditions, platelet ATP and ADP content (firefly luciferase method) and plasma beta-thromboglobulin level were measured in 51 healthy young volunteers, 10 patients with typical DIC syndrome during time course of cancer, 27 patients in acute stage of thrombosis in cerebral, coronary and femoral arteries, 29 patients in recovery stage of thrombosis and 69 patients one day before, and one day, one week and one month after a laparotomy. Platelet count and volume were counted by a Coulter Counter and Channelyzer. Platelet aggregation induced by ADP, adrenaline and collagen was also measured. In the healthy, platelet mode volume was 4.21 ± 0.08 μ3 (mean ± SE). beta-TG was 29.9 ± 5.9 ng/ml, and ATP and ADP contents were 5.81 ± 0.17 and 3.19 ± 0.09 μmoles/1011 platelets and ATP/ADP was 1.82 ± 0.05. In DIC, acute stage of thrombosis and one week after laparotomy, platelet volume became to smaller and ADP content decreased significantly. Changes in beta-TG level were rather variable. Platelet aggregation increased in thrombosis and postoperative state, while it decreased in DIC. In DIC, decrease in ATP and ADP content was marked as compared with other groups. It suggests that ADP content In platelets may reflect release reaction in vivo. Following the release reaction, platelet aggregability may increase. However, platelets with large decrease in adenine nucleotides content may have hypofunction.

scholarly journals Decrease in subunit aggregation of phosphoribosylpyrophosphate synthetase: a mechanism for decreased nucleotide concentrations in pyruvate kinase-deficient human erythrocytes

Blood ◽  
1986 ◽  
Vol 68 (5) ◽  
pp. 1024-1029 ◽  
Author(s):  
CR Zerez ◽  
NA Lachant ◽  
KR Tanaka
Keyword(s):  
Pyruvate Kinase ◽  
Nicotinamide Adenine Dinucleotide ◽  
Adenine Nucleotide ◽  
Adenine Nucleotides ◽  
Gel Permeation Chromatography ◽  
Metabolic Abnormalities ◽  
Gel Permeation ◽  
Reduced Nicotinamide Adenine Dinucleotide

Abstract Pyruvate kinase (PK)-deficient RBCs have several unexplained metabolic abnormalities, such as decreased concentrations of total adenine nucleotides (AMP, ADP, and ATP) and total (oxidized and reduced) nicotinamide adenine dinucleotide (NAD). Because 5-phosphoribosyl-1- pyrophosphate (PRPP) is an intermediate in the synthesis of adenine nucleotides and NAD, we investigated PRPP synthetase (PRPPS), the enzyme responsible for PRPP synthesis. This enzyme is regulated, in part, by changes in its state of subunit aggregation. The proportion of aggregated PRPPS can be altered in vitro by ATP and 2,3- diphosphoglycerate (DPG). Because PK-deficient RBCs have decreased ATP and increased DPG concentrations, we examined the state of subunit aggregation of PRPPS in RBCs from normal and PK-deficient subjects, using gel permeation chromatography. Young normal RBCs have more aggregated PRPPS than do older RBCs. In contrast, due to their decreased ATP and increased DPG concentrations, PK-deficient RBCs contain less aggregated PRPPS than do RBCs of comparable age without PK deficiency. These data suggest that PRPPS should be less active in vivo in PK-deficient RBCs. This may play a key role in mediating the decreases in total adenine nucleotide and total NAD concentrations in these RBCs.

scholarly journals The brush border of rabbit kidney, a cellular compartment free of glycolytic enzymes

1978 ◽  
Vol 174 (2) ◽  
pp. 509-515 ◽  
Author(s):  
Dietrich Busse ◽  
Hans Ulrich Wahle ◽  
Harald Bartel ◽  
Barbara Pohl
Keyword(s):  
Lactate Dehydrogenase ◽  
Pyruvate Kinase ◽  
Brush Border ◽  
Gradient Centrifugation ◽  
Fluorescein Isothiocyanate ◽  
Glycolytic Enzymes ◽  
Rabbit Kidney ◽  
Cellular Compartment ◽  
Fluorescein Isothiocyanate Dextran

Activities of four enzymes of the glycolytic pathway, hexokinase, glyceraldehyde 3-phosphate dehydrogenase, pyruvate kinase and lactate dehydrogenase, were determined in a vesicular brush-border preparation from rabbit kidneys. The specific activities of the enzymes were decreased several-hundredfold in the brush-border preparation compared with a kidney homogenate, but the enzymes were not totally absent. Density-gradient centrifugation of the brush-border preparation yielded brush border of even higher purity and also a characteristic pattern of distribution for each of the contaminating intracellular membranes. The presence of hexokinase in the brush-border preparation could be traced to contaminating mitochondria, and that of glyceraldehyde 3-phosphate dehydrogenase, pyruvate kinase and lactate dehydrogenase to contaminating vesicles derived from the endoplasmic reticulum. The brush-border vesicles contained some ATP. An intravesicular concentration of 0.1mm was estimated, indicating that the vesicles had retained at least a part of their original content. Experiments in which fluorescein isothiocyanate-dextran (mol.wt. 20000) was present during cell lysis revealed that much, but not all, of the brush-border contents had been exchanged with the medium. The complete absence of glycolytic enzymes from brush-border vesicles, which had retained part of their original content, indicates that the brush border does not contain glycolytic enzymes in vivo and can be thought of as a compartment of its own, somehow separated from the cytoplasm.

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