Ectonucleotide pyrophosphatase/phosphodiesterase family member 1 is an enzyme that in humans is encoded by the ENPP1 gene. This gene is a member of the ecto-nucleotide pyrophosphatase/phosphodiesterase (ENPP) family. The encoded protein is a type II transmembrane glycoprotein comprising two identical disulfide-bonded subunits. This protein has broad specificity and cleaves a variety of substrates, including phosphodiester bonds of nucleotides and nucleotide sugars and pyrophosphate bonds of nucleotides and nucleotide sugars. This protein may function to hydrolyze nucleoside 5' triphosphates to their corresponding monophosphates and may also hydrolyze diadenosine polyphosphates. Mutations in this gene have been associated with Idiopathic infantile arterial calcification, ossification of the posterior longitudinal ligament of the spine (OPLL), and insulin resistance. Ectonucleotide pyrophosphatase/phosphodiesterase 1 has been shown to interact with Insulin receptor. GRCh38: Ensembl release 89: ...

TY - JOUR. T1 - Degradation of the gluconeogenic enzyme fructose-1, 6-bisphosphatase is dependent on the vacuolar ATPase.. AU - Liu, Jingjing. AU - Brown, C. Randell. AU - Chiang, Hui-ling. PY - 2005/1/1. Y1 - 2005/1/1. N2 - The key gluconeogenic enzyme fructose-1,6-bisphosphatase (FBPase) is induced during glucose starvation. After the addition of glucose, inactivated FBPase is selectively targeted to Vid (vacuolar import and degradation) vesicles and then to the vacuole for degradation. To identify proteins involved in this pathway, we screened various libraries for mutants that failed to degrade FBPase. Via these approaches, subunits of the vacuolar- H+ -ATPase (V-ATPase) have been identified repeatedly. The V-ATPase has established roles in endocytosis, sorting of carboxypeptidase Y and homotypic vacuole fusion. Here, we show that mutants lacking Stv1p, Vph1p, and other subunits of the V-ATPase are defective for FBPase degradation. FBPase was detected in Vid vesicles. However, most FBPase ...

WHAT IS THE CONTROVERSY SURROUNDING HIGH FRUCTOSE CORN SYRUP? What is high fructose corn syrup? In the 1970's, Japanese researchers discovered a process that converted cornstarch into a sweetener called high fructose corn syrup (hfcs). It contained 55% fructose, and 45% glucose, which makes it as sweet as sucrose (aka table sugar-about 50% each fructose and glucose). In Canada, hfcs will be identified in ingredient lists as glucose/fructose. As the price of sugar increased (as most sugar is imported), food processors began to use high fructose corn syrup more often. It is much cheaper, as corn is grown in abundance...

Americans love food that tastes good and we find that food and drink companies are adding high-fructose corn syrup as a sweetener to enhance flavors. Why are companies choosing this over other sweeteners? Is there a difference between corn syrup and high-fructose corn syrup? Why is it that some brands use high-fructose corn syrup for the U.S. market, yet sugar for Canadian and European markets?. The simple answer as to why high-fructose corn syrup is used is cost. It is a lot cheaper for food manufactures to use high-fructose corn syrup than real sugar. Also the supply of high-fructose corn syrup is almost limitless. Corn subsidies by the government can be the reason for both cost and supply.. Corn syrup and high-fructose corn syrup are two different products even though both products are made from corn starch. Regular corn syrup is 100% glucose yet high-fructose corn syrup has some of its glucose converted to fructose enzymatically. Scientists are examining the potentially negative effects of ...

Spermatids of the snail Helix aspersa were studied after fixation in buffered osmium tetroxide and after applying Novikoff and Goldfischer's method (15) for demonstrating thiamine pyrophosphatase (TPPase) activity both with the light and the electron microscope. The appearance of cells in the light microscope after localizing the enzyme is very similar to the appearance after the application of classical Golgi techniques. The electron microscope shows the "dictyosomes" to consist of non-granular membranes, vesicles, and vacuoles typical of the ultrastructure of the Golgi apparatus. Sites of TPPase activity are localized by deposits of lead phosphate, and are found between the membranes of the Golgi apparatus, in the small vesicles, in multivesicular bodies often found associated with it, but not within the large Golgi vacuoles. Heavy deposits are found on the caudal part of the nuclear envelope, but not in the acrosomal granule. It is suggested that TPPase may act as an intermediary in acrosome ...

Dive into the research topics of 'Sedimentation Study of a Catalytically Active form of Rabbit Muscle Phosphofructokinase at pH 8.55'. Together they form a unique fingerprint. ...

Fructose-1,6-bisphosphatase deficiency is an autosomal recessive disorder caused by a defect in FBP1 gene and characterized by impaired gluconeogenesis ...

Results: SAM domain and HD domain-containing protein 1 (SAMHD1), an innate immune factor that suppresses HIV replication, was identified and confirmed as highly expressed in immune complexes from 16 hereditary and idiopathic PAH versus 12 control lungs. Elevated SAMHD1 was localized to endothelial cells, perivascular dendritic cells, and macrophages, and SAMHD1 antibodies were prevalent in tertiary lymphoid tissue. An unbiased screen using metagenomic sequencing related SAMHD1 to increased expression of human endogenous retrovirus K (HERV-K) in PAH versus control lungs (n=4). HERV-K envelope and deoxyuridine triphosphate nucleotidohydrolase mRNAs were elevated in PAH versus control lungs (n=10), and proteins were localized to macrophages. HERV-K deoxyuridine triphosphate nucleotidohydrolase induced SAMHD1 and proinflammatory cytokines (eg, interleukin 6, interleukin 1β, and tumor necrosis factor α) in circulating monocytes, pulmonary arterial endothelial cells, and also activated B cells. ...

Burkholderia phymatum STM815 is a β-rhizobial strain that can effectively nodulate several species of the large legume genus Mimosa. Two Tn5-induced mutants of this strain, KM16-22 and KM51, failed to form root nodules on Mimosa pudica, but still caused root hair deformation, which is one of the early steps of rhizobial infection. Both mutants grew well in a complex medium. However, KM16-22 could not grow on minimal medium unless a sugar and a metabolic intermediate such as pyruvate were provided, and KM51 also could not grow on minimal medium unless a sugar was added. The Tn5-interrupted genes of the mutants showed strong homologies to pgm, which encodes 2,3-biphosphoglycerate-dependent phosphoglycerate mutase (dPGM), and fbp, which encodes fructose 1,6-bisphosphatase (FBPase). Both enzymes are known to be involved in obligate steps in carbohydrate metabolism. Enzyme assays confirmed that KM16-22 and KM51 had indeed lost dPGM and FBPase activity, respectively, whilst the activities of these enzymes

A case of hereditary fructose intolerance is reported in a girl aged 2 years at the time of her death. She had apparently progressed normally until the age of 14 months. At 19 months she was admitted to hospital with failure to thrive, hepatomegaly, and superficial infections. Investigations revealed hypoglycaemia, persistent acidosis, aminoaciduria, and a high liver glycogen level which suggested that she had glycogen storage disease. There was also some evidence of malabsorption.. At necropsy the liver enzyme estimations showed that fructose 1-phosphate aldolase activity was absent and that fructose 1,6-diphosphate aldolase activity was reduced. Hereditary fructose intolerance and glycogen storage disease have been confused in the past on clinical grounds, but a high liver glycogen level has not previously been reported in hereditary fructose intolerance.. ...

K12316 GAA; lysosomal alpha-glucosidase [EC:3.2.1.20] K00963 UGP2; UTP--glucose-1-phosphate uridylyltransferase [EC:2.7.7.9] K00963 UGP2; UTP--glucose-1-phosphate uridylyltransferase [EC:2.7.7.9] K01513 ENPP1_3; ectonucleotide pyrophosphatase/phosphodiesterase family member 1/3 [EC:3.1.4.1 3.6.1.9] K05349 bglX; beta-glucosidase [EC:3.2.1.21] K05349 bglX; beta-glucosidase [EC:3.2.1.21] K05349 bglX; beta-glucosidase [EC:3.2.1.21] K05349 bglX; beta-glucosidase [EC:3.2.1.21] K05349 bglX; beta-glucosidase [EC:3.2.1.21] K01225 CBH1; cellulose 1,4-beta-cellobiosidase [EC:3.2.1.91] K01225 CBH1; cellulose 1,4-beta-cellobiosidase [EC:3.2.1.91] K00693 GYS; glycogen synthase [EC:2.4.1.11] K00750 GYG1; glycogenin [EC:2.4.1.186] K00750 GYG1; glycogenin [EC:2.4.1.186] K00750 GYG1; glycogenin [EC:2.4.1.186] K00750 GYG1; glycogenin [EC:2.4.1.186] K00700 GBE1; 1,4-alpha-glucan branching enzyme [EC:2.4.1.18] K00688 PYG; glycogen phosphorylase [EC:2.4.1.1] K01196 AGL; glycogen debranching enzyme [EC:2.4.1.25 ...

A friend at work brought this scary phenomenon to my attention. According to wikipedia, a recent study found traces of mercury in high fructose corn syrup. Here's the excerpt from wikipedia: In 2009, according to a peer-reviewed report published by Environmental Health, high-fructose corn syrup has been found to be commonly tainted with mercury. Traces of mercury have been found in name-brand foods from makers such as Quaker, Hunt's, Manwich, Hershey's, Smucker's, Kraft, Nutri-Grain, and Yoplait. Mercury is a highly toxic substance. It makes its way into high-fructose corn syrup during its production. Several chemicals are required to make high-fructose corn syrup, including caustic soda, hydrochloric acid, alpha-amylase, gluco-amylase, isomerase, powdered carbon, calcium chloride, and magnesium sulfate. Caustic soda and hydrochloric acid can contain traces of mercury.The Institute for Agriculture and Trade Policy, tested 55 consumer items, finding mercury in one third of the samples ranging ...

Phosphofructokinase deficiency, also known as glycogen storage disease type VII or Tarui's disease, is a extremely rare muscular metabolic disorder, with an autosomal recessive inheritance pattern. It may affect humans as well as other mammals (especially dogs). It was named after the Japanese physician, Seiichiro Tarui (1927- ) who first observed the condition in 1965. Human PFK deficiency is categorized into four types: classic, late-onset, infantile and hemolytic. These types are differentiated by age at which symptoms are observed and which symptoms present. Classic phosphofructokinase deficiency is the most common type of this disorder. This type presents with exercise-induced muscle cramps and weakness (sometimes rhabdomyolysis), myoglobinuria, as well as with haemolytic anaemia causing dark urine a few hours later. Hyperuricemia is common, due to the kidneys' inability to process uric acid following damage resulting from processing myoglobin. Nausea and vomiting following strenuous ...

Looking for online definition of fructose 1,6-diphosphate aldolase in the Medical Dictionary? fructose 1,6-diphosphate aldolase explanation free. What is fructose 1,6-diphosphate aldolase? Meaning of fructose 1,6-diphosphate aldolase medical term. What does fructose 1,6-diphosphate aldolase mean?

The genome of Bacillus cereus contains 26 Nudix hydrolase genes, second only to its closest relative, Bacillus anthracis which has 30. All 26 genes have been cloned, 25 have been expressed, and 21 produced soluble proteins suitable for analysis. Substrates for 16 of the enzymes were identified; these included ADP-ribose, diadenosine polyphosphates, sugar nucleotides, and deoxynucleoside triphosphates. One of the enzymes was a CDP-choline pyrophosphatase, the first Nudix hydrolase active on this substrate. Furthermore, as a result of this and previous work we have identified a new sub-family of the Nudix hydrolase superfamily recognizable by a specific amino acid motif outside of the Nudix box.

This condition occurs when the body is missing an enzyme called aldolase B. This substance is needed to break down fructose.. If a person without this substance eats fructose or sucrose (cane or beet sugar, table sugar), complicated chemical changes occur in the body. The body cannot change its stored form of sugar (glycogen) into glucose. As a result, blood sugar falls and dangerous substances build up in the liver.. Hereditary fructose intolerance is inherited, which means it can be passed down through families. If both parents carry a nonworking copy of the adolase B gene, each of their children has a 25% (1 in 4) chance of being affected. ...

The intestinal nematode Baylisascaris schroederi is an important cause of death for wild and captive giant pandas. Inorganic pyrophosphatases (PPases) are critical for development and molting in nematode parasites and represent potential targets for vaccination. Here, a new PPase homologue, Bsc-PYP-1, from B. schroederi was identified and characterized, and its potential as a vaccine candidate was evaluated in a mouse challenge model. Sequence alignment of PPases from nematode parasites and other organisms show that Bsc-PYP-1 is a nematode-specific member of the family I soluble PPases. Immunohistochemistry revealed strong localization of native Bsc-PYP-1 to the body wall, gut epithelium, ovary and uterus of adult female worms. Additionally, Bsc-PYP-1 homologues were found in roundworms infecting humans (Ascaris lumbricoides), swine (Ascaris suum) and dogs (Toxocara canis). In two vaccine trials, recombinant Bsc-PYP-1 (rBsc-PYP-1) formulated with Freund complete adjuvant induced significantly high

Background and Aims: The influence of a high-fructose diet and probiotics on the male reproductive system and the testicular apoptotic pathway has been poorly documented. In this study, we aimed to investigate the influence of Lactobacillus plantarum and Lactobacillus helveticus supplementation on apoptotic factors such as sirtuin1, caspase3 and bcl-2 on the testicular tissue of high-fructose-fed rats. Methods: Fructose was given to the rats as a 20% solution in drinking water for 15 weeks. Gene expressions were established by real-time PCR. Protein levels were determined by Western blot analysis. Results: Fructose consumption did not change mRNA expression of SIRT1, but did resulted in a decreased protein level. Dietary fructose reduced bcl-2 mRNA and protein expressions, whereas no changes were observed in the gene and protein expression levels of factor caspase-3. Both Lactobacillus supplementations increased SIRT1 protein expression without changing the mRNA levels in fructose-fed rats. The ...

The enzyme activities and isozyme distribution of the three glycolytic regulator enzymes hexokinase, phosphofructokinase and pyruvate kinase were studied in lymphocytes of patients with chronic lymphocytic leukemia. Isozyme distribution patterns were determined by kinetic measurements, electrophoresis and immunoprecipitation. The CLL lymphocytes were different from normal non-T lymphocytes with respect to hexokinase ... read more residual activity in the presence of glucose-1,6-P2, pyruvate kinase residual activity in the presence of alanine, and phosphofructokinase activity after stimulation by glucose-1,6-P2. No differences could be discerned in enzyme activities between the CLL and the normal T and non-T lymphocytes. show less ...

A collection of disease information resources and questions answered by our Genetic and Rare Diseases Information Specialists for Hereditary fructose intolerance

The protein encoded by this gene is involved in both the synthesis and degradation of fructose-2,6-bisphosphate, a regulatory molecule that controls glycolysis in eukaryotes. The encoded protein has a 6-phosphofructo-2-kinase activity that catalyzes the synthesis of fructose-2,6-bisphosphate, and a fructose-2,6-biphosphatase activity that catalyzes the degradation of fructose-2,6-bisphosphate. This protein regulates fructose-2,6-bisphosphate levels in the heart, while a related enzyme encoded by a different gene regulates fructose-2,6-bisphosphate levels in the liver and muscle. This enzyme functions as a homodimer. Two transcript variants encoding two different isoforms have been found for this gene. [provided by RefSeq, Jul 2008 ...

The native form of turkey liver fructose 1,6-bisphosphatase (FbPase) consists of four identical subunits, each of which contains one tryptophan residue. The fluorescence emission spectra of the tryptophan residues have been recorded as a function of changes in pH, substrate (fructose 1,6-bisphosphate) and inhibitor (adenosine-5' monophosphate) binding, and the addition of the metal cofactors Mg+2, Mn+2 and Co+2 . Changes in the fluorescence emission spectra of the tryptophan residues indicate that conformational changes in the enzyme occur under the above conditions.

It has been reported that inosine triphosphatase (ITPA) gene variants protect against ribavirin-induced anemia in patients treated for chronic hepatitis C. IL28B variants also influence the treatment response of peginterferon plus ribavirin treatment in these patients. In the present study, we examined how ITPA and IL28B genotypes have clinical impacts on treatment-induced hematotoxicities and treatment response in HCV-infected patients treated with peginterferon plus ribavirin. ITPA genotypes (rs1127354 and rs6051702) and IL28B genotype (rs8099917) were determined by TaqMan SNP assay. We compared clinical background, treatment course and treatment response in terms of these genotypes. Only IL28B rs8099917 major type could predict sustained virological response. ITPA rs1127354 major type leads to significantly greater ribavirin-induced anemia than ITPA rs1127354 minor type between days 0 and 84. We noticed that IL28B rs8099917 minor genotype was associated with higher reduction of neutrophils and

Fructose-2,6-bisphosphatase is important in regulation of gluconeogenesis & glycolysis as it catalyzes the dephosphorylation of fructose-2,6-bisphosphate. Because fructose-2,6-bisphosphate activates phosphofructokinase-1 (a critical enzyme in glycolysis) and inhibits fructose-1,6-bisphosphatase (a critical enzyme in gluconeogenesis), the activity of fructose-2,6-bisphosphatase decreases glycolysis and increases gluconeogenesis. Fructose-2,6-bisphosphatase is subject to product inhibition by fructose-6-phosphate. Fructose-2,6-bisphosphatase also undergoes addition of a phosphate group to a single serine residue by cAMP-dependent protein kinase (known as covalent modification), which activates (increases catalytic activity) of Fructose-2,6-bisphosphatase. ...

K00567 ogt; methylated-DNA-[protein]-cysteine S-methyltransferase [EC:2.1.1.63] K03648 UNG; uracil-DNA glycosylase [EC:3.2.2.27] K03575 mutY; A/G-specific adenine glycosylase [EC:3.2.2.31] K10773 NTH; endonuclease III [EC:4.2.99.18] K10844 ERCC2; DNA excision repair protein ERCC-2 [EC:3.6.4.12] K03574 mutT; 8-oxo-dGTP diphosphatase [EC:3.6.1.55] K03574 mutT; 8-oxo-dGTP diphosphatase [EC:3.6.1.55] K03574 mutT; 8-oxo-dGTP diphosphatase [EC:3.6.1.55] K03574 mutT; 8-oxo-dGTP diphosphatase [EC:3.6.1.55] K03574 mutT; 8-oxo-dGTP diphosphatase [EC:3.6.1.55] K03574 mutT; 8-oxo-dGTP diphosphatase [EC:3.6.1.55] K03574 mutT; 8-oxo-dGTP diphosphatase [EC:3.6.1.55] K03574 mutT; 8-oxo-dGTP diphosphatase [EC:3.6.1.55] K01520 dut; dUTP pyrophosphatase [EC:3.6.1.23] K03649 mug; double-stranded uracil-DNA glycosylase [EC:3.2.2.28] K01247 alkA; DNA-3-methyladenine glycosylase II [EC:3.2.2.21] K10563 mutM; formamidopyrimidine-DNA glycosylase [EC:3.2.2.23 4.2.99.18] K10563 mutM; formamidopyrimidine-DNA glycosylase ...

Erythritol is an important nutrient for several α-2 Proteobacteria, including N2-fixing plant endosymbionts and Brucella, a worldwide pathogen that finds this four-carbon polyol in genital tissues. Erythritol metabolism involves phosphorylation to l-erythritol-4-phosphate by the kinase EryA and oxidation of the latter to l-3-tetrulose 4-phosphate by the dehydrogenase EryB. It is accepted that further steps involve oxidation by the putative dehydrogenase EryC and subsequent decarboxylation to yield triose-phosphates. Accordingly, growth on erythritol as the sole C source should require aldolase and fructose-1,6-bisphosphatase to produce essential hexose-6-monophosphate. However, we observed that a mutant devoid of fructose-1,6-bisphosphatases grew normally on erythritol and that EryC, which was assumed to be a dehydrogenase, actually belongs to the xylose isomerase superfamily. Moreover, we found that TpiA2 and RpiB, distant homologs of triose phosphate isomerase and ribose 5-phosphate isomerase ...

Abstract Regarding efficacy of new antiepileptic drugs (AEDs) for seizure control, there are three important clinical questions.Download and Read New Antiepileptic Drugs Epilepsy Research Supplement No 3 New Antiepileptic Drugs Epilepsy Research Supplement No 3 It sounds good when knowing the.Several studies show drugs used to treat AEDS reduce bone density, increase risk of fracture, especially for the up to 50% of users unresponsive to AEDS.Efficacy and tolerability of the new antiepileptic drugs I: Treatment of new onset epilepsy. new AEDs with many of the non-AED drugs.AMR has developed set of analyst tools and data models to supplement.. Research identifies protein that could help patients respond more positively to epilepsy drug therapies.Seizures and epilepsy: Hope through research. for treatment of drug-resistant epilepsy ...

Exopolyphosphatases and pyrophosphatases play important but still incompletely understood roles in energy metabolism, and also in other aspects of cell biology such as osmoregulation or signal transduction. Earlier work has suggested that a human exopolyphosphatase, Prune, might exhibit cyclic nucleotide phosphodiesterase activity. The kinetoplastida, a large order of unicellular eukaryotes that contains many important pathogens such as Trypanosoma brucei (human sleeping sickness), Trypanosoma cruzi (Chagas disease) or Leishmania ssp (several clinically dinstinct leishmaniases) all contain several exo- and pyrophosphatases. The current study provides a systematic classification of these enzymes, which now allows to situate the information that is already available on some of these enzymes. It then analyses the exopolyphosphatase TbrPPX1 of T. brucei in detail, using RNA interference and genetic knockouts in an attempt to define its function, and immunofluorescence microscopy to study its subcellular

1. The fluorescent ATP analogue 1,N6-etheno-ATP is a good substrate and an efficient allosteric inhibitor of rabbit skeletal-muscle phosphofructokinase. 2. Fluorescence energy transfer occurs between bound 1,N6-etheno-ATP and phosphofructokinase. 1,N6-Etheno-ATP fluorescence is enhanced, intrinsic protein fluorescence is quenched, and the excitation spectrum of 1,N6-etheno-ATP fluorescence is characteristic of protein absorption. 3. The binding reaction of 1,N6-etheno-ATP observed by stopped-flow fluorimetry is biphasic. The fast phase results from binding to the catalytic site alone. The slow phase results from the allosteric transition of the R conformation into the T conformation induced by the binding of 1,N6-etheno-ATP to the regulatory site. 4. The fluorescence signal that allows the transition of the R conformation into the T conformation to be observed does not arise from 1,N6-etheno-ATP bound to the regulatory site. It arises instead from 1,N6-etheno-ATP bound to the catalytic site as a ...

TY - JOUR. T1 - A protein tyrosine phosphatase-like protein from baculovirus has RNA 5′-triphosphatase and diphosphatase activities. AU - Takagi, Toshimitsu. AU - Taylor, Gregory S.. AU - Kusakabe, Takahiro. AU - Charbonneau, Harry. AU - Buratowski, Stephen. N1 - Copyright: Copyright 2018 Elsevier B.V., All rights reserved.. PY - 1998/8/18. Y1 - 1998/8/18. N2 - The superfamily of protein tyrosine phosphatases (PTPs) includes at least one enzyme with an RNA substrate. We recently showed that the RNA triphosphatase domain of the Caenorhabditis elegans mRNA capping enzyme is related to the PTP enzyme family by sequence similarity and mechanism. The PTP most similar in sequence to the capping enzyme triphosphatase is BVP, a dual-specificity PTP encoded by the Autographa californica nuclear polyhedrosis virus. Although BVP previously has been shown to have modest tyrosine and serine/threonine phosphatase activity, we find that it is much more potent as an RNA 5′-phosphatase. BVP sequentially ...

OBJECTIVE: To test the hypothesis that high concentrations of extracellular inorganic pyrophosphate (PPi), which associate with increased cell synthesis and turnover in cartilage, may act as a marker for structural outcome in knee osteoarthritis (OA). METHOD: One hundred and thirty five consecutive patients referred to hospital with knee OA (59 men, 76 women; mean age 71 years, range 41-88) were followed prospectively for a median of 2.5 years (interquartile range 1.75-3.0). Synovial fluid (SF) aspirated at presentation (202 OA knees: 68 bilateral, 66 unilateral) was assessed for PPi content by radiometric assay. Knee radiographs at presentation and at final review were assessed for change in global (Kellgren) and individual features (narrowing, osteophyte, sclerosis, cyst, attrition) of OA. RESULTS: The median SF PPi level was 10.5 mumol (range 0.07-72.4). At baseline, high PPi was significantly associated with presence of calcium pyrophosphate crystals, chondrocalcinosis, and bone attrition. ...

Perfusion of the isolated rat heart with Ca2+ concentrations exceeding 3 mM activated phosphofructokinase and phosphorylase, and decreased the concentration of cyclic AMP. Half-maximal activation of phosphofructokinase occurred at 5 mM-CaCl2; significant activation of phosphorylase did not occur until the concentration of CaCl2 exceeded 12 mM. The time course for the activation of phosphofructokinase at 12 mM-CaCl2 indicated that maximal activation occurred within 2 min; when the perfusion-medium Ca2+ concentration was re-adjusted to 3 mM, the phosphofructokinase activity returned to pre-activation values within 30 s. The addition of Ca2+ to extracts of heart did not activate phosphofructokinase. The activation of phosphofructokinase by sub-maximal doses of adrenaline and Ca2+ were not additive. The activation of phosphofructokinase by 1 microM-adrenaline + 10 microM-propranolol and by 1 microM-isoprenaline was inhibited by high concentrations of K+ (22-56 mM). The activation of ...

Aim. During ischemia, the glycolytic pathway is up-regulated to anaerobically produce adenosine triphosphate (ATP). However, this is short-lived, due to negative feedback on phosphofructokinase from accumulating lactate. Since fructose-1,6-diphosphate (FDP) enters glycolysis distal to this inhibitory site, exogenously administered FDP may yield ATP-independent lactate accumulation and thus ameliorate ischemic injury. The aim of this prospective randomized study was to investigate whether the improved myocardial preservation by FDP could be attributed to improved intermediary metabolism in patients who underwent coronary artery bypass grafting surgery (CABG ...

When oxygen is limiting, cells adjust their metabolism through the transcription factors hypoxia-inducible factors (HIFs). Loss of function of VHL, a protein necessary to maintain the low abundance of HIFs under normoxic conditions, results in constitutively active HIFs and contributes to some forms of cancer, in particular clear cell renal carcinoma (ccRCC). Li et al. found through metabolomic analysis that primary human ccRCCs had higher glucose metabolism but lower gluconeogenesis than matched normal kidney tissue. The tumors universally had reduced or undetectable amounts of the enzyme fructose-1,6-bisphosphatase 1 (FBP1). Knockdown of endogenous FBP1 enhanced the proliferation of HK-2 cells, a proximal tubule cell line. Ectopic expression of FBP1 (to amounts similar to those in HK-2 cells) in a ccRCC line inhibited tumor growth when xenografted in mice and inhibited anchorage-dependent and anchorage-independent growth in culture. Ectopic expression of FBP1 in ccRCC cells reduced glycolysis ...

Detailed mapping of glucose and lactate metabolism along the radius of the hepatic lobule was performed in situ in rat livers perfused with 1.5 mM lactate before and during the addition of 5 mM fructose. The majority of fructose uptake occurred in the periportal region; 45% of fructose taken up in the periportal half of the lobular volume being converted into glucose. Periportal lactate uptake was markedly decreased by addition of fructose. Basal perivenous lactate output, which was derived from glucose synthesized periportally, was increased in the presence of fructose. During fructose infusion there was a small decrease in cell pH periportally, but acidification of up to 0.5 pH units perivenously. The evidence suggests that in situ the apparent direct conversion of fructose into lactate represents, to a substantial extent, the result of periportal conversion of fructose into glucose and the subsequent uptake and glycolysis to lactate in the perivenous zone of some of that glucose. 31P NMR ...

Sucralose Double Whammy All, At some times in the past at least, sucralose (aka Splenda) has been considered by some CR folks to be one of the better artificial sweeteners due to it's apparent inert nature in the human digestive system. But that seems to have been called into question recently, as highlighted by two popular press pieces that came across my radar today. The first is this story on the recent downgrade of Splenda from "Caution" to "Avoid" by the Center for Science in the Public Interest (CSPI), as announced here. Quoting the CSPI president: "We recommend that consumers avoid sucralose, or Splenda, and we recommend consumers also avoid saccharin, aspartame, and acesulfame potassium," said CSPI president Michael F. Jacobson. "That said, the risk posed by over-consumption of sugar and high-fructose corn syrup, particularly from soda and other sugar-sweetened beverages, of diabetes, heart disease, and obesity, far outweighs the cancer risk posed by sucralose and most other artificial ...

Nonalcoholic fatty liver disease, a condition closely linked to obesity, affects roughly 25 percent of people in the U.S. There is no drug treatment for the disease, although weight loss can reduce the buildup of fat in the liver.. Now, studying mice, new research shows that a natural sugar called trehalose prevents the sugar fructose - thought to be a major contributor to nonalcoholic fatty liver disease - from entering the liver and triggers a cellular housekeeping process that cleans up excess fat buildup inside liver cells.. The research, by a team at Washington University School of Medicine in St. Louis, appears Feb. 23 in the journal Science Signaling.. "In general, if you feed a mouse a high-sugar diet, it gets a fatty liver," said first author Brian J. DeBosch, MD, PhD, a pediatric gastroenterologist. "We found that if you feed a mouse a diet high in fructose plus provide drinking water that contains three percent trehalose, you completely block the development of a fatty liver. Those ...

Ketohexokinase (KHK; fructokinase, E.C. 2.7.1.3) catalyzes the phosphorylation of the ketose sugar fructose to fructose-1-phosphate. A number of other furanose sugars can also act as KHK substrates (1). KHK activity is highest in the liver, followed by renal cortex and small intestine (2). Its primary role in these sites seems to be clearance of dietary fructose through a specialized pathway involving aldolase B and triokinase.. In other tissues, the role of KHK is not well defined but might be significant. In the lung, for example, fructokinase activity is demonstrable (3), and in insulin-deficient states, a modest level of fructose metabolism through fructose-1-phosphate is preserved, even when peripheral glucose utilization is significantly depressed (4). Metabolic labeling experiments also indicate a significant contribution of KHK to fructose metabolism in the parotid gland, as well as in the pancreatic islet (5).. One particular process in which KHK could also be involved is the modulation ...

Glucose phosphate isomerase (GPI) deficiency with severe haemolysis and hydrops fetalis was found in the first child of unrelated, healthy Caucasian parents. The child died at 3 hours. Both parents were found to have 50% of normal red cell GPI activity and qualitative tests on their red cells and white cells showed that each was heterozygous for a different GPI variant allele associated with enzyme deficiency. Tests on the placenta showed that the propositus was a 'compound' heterozygote. Examination of amniotic cells obtained by amniocentesis on the mother at 28 weeks in her second pregnancy led to the prenatal diagnosis of GPI deficiency. This second child, a 'compound' heterozygote at the GPI locus indistinguishable from the first, was successfully treated by immediate exchange transfusion and subsequent blood transfusions.

Flavins are notoriously photolabile, but while the photoproducts derived from the iso -alloxazine ring are well known the other photoproducts are not. In the case of FAD, typically the main cellular flavin, the other photoproducts are predicted to include four- and five-carbon sugars linked to ADP. These FAD photoproducts were shown to be potent glycating agents, more so than ADP-ribose. Such toxic compounds would require disposal via an ADP-sugar diphosphatase or other route. Comparative analysis of bacterial genomes uncovered a candidate disposal gene that is chromosomally clustered with genes for FAD synthesis or transport and is predicted to encode a protein of the PhnP cyclic phosphodiesterase family. The representative PhnP family enzyme from Koribacter versatilis (here named Fpd, FAD photoproduct diphosphatase) was found to have high, Mn2+-dependent diphosphatase activity against FAD photoproducts, FAD, and ADP-ribose, but almost no phosphodiesterase activity against riboflavin ...

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Glucose & Fructose Metabolism. Glucose and fructose are simple sugars that have the same chemical formula with a different structural arrangement of the atoms. Glucose is a source of energy for all of your tissues, and can be stored by the body for energy upon demand. It's also used to make other sugars needed ...

The malate dehydrogenase isozyme MDH3 of Saccharomyces cerevisiae was found to be localized to peroxisomes by cellular fractionation and density gradient centrifugation. However, unlike other yeast peroxisomal enzymes that function in the glyoxylate pathway, MDH3 was found to be refractory to catabolite inactivation, i.e. to rapid inactivation and degradation following glucose addition. To examine the structural requirements for organellar localization, the Ser-Lys-Leu carboxyl-terminal tripeptide, a common motif for localization of peroxisomal proteins, was removed by mutagenesis of the MDH3 gene. This resulted in cytosolic localization of MDH3 in yeast transformants. To examine structural requirements for catabolite inactivation, a 12-residue amino-terminal extension from the yeast cytosolic MDH2 isozyme was added to the amino termini of the peroxisomal and mislocalized 'cytosolic' forms of MDH3. This extension was previously shown to be essential for catabolite inactivation of MDH2 but failed to

Diacylglycerol kinases (DAGKs) catalyse ATP-dependent phosphorylation of sn-1,2-diacylglycerol that arises during stimulated phosphatidylinositol turnover. DAGKα is activated in vitro by Ca2+ and by acidic phospholipids. The regulatory region of DAGKα includes an N-terminal RVH motif and EF hands that mediate Ca2+-dependent activation. DAGKα also contains tandem C1 protein kinase C homology domains. We utilized yeast, Saccharomyces cerevisiae, which lacks an endogenous DAGK, to express DAGKα and to determine the enzymic activities of different mutant forms of pig DAGKα in vitro. Six aspartate residues conserved in all DAGKs were individually examined by site-directed mutagenesis. Five of these aspartate residues reside in conserved blocks that correspond to sequences in the catalytic site of phosphofructokinases. Mutation of D434 (Asp434) or D650 abolished all DAGKα activity, whereas substitution of one among D465, D497, D529 and D697 decreased the activity to 6% or less of that for ...

DNA was isolated from four unrelated glucose phosphate isomerase-deficient patients. Seven new mutations in the coding region were found: 247 C--,T, 671 C--,T, 818 G--,A, 833 C--,T, 1039 C--,T, 1459 C--,T, and 1483 G--,A. Three patients were compound heterozygotes, and one patient was a homozygote of 247 C--,T/247 C--,T. Six mutations were found to involve highly conserved amino acids of glucose phosphate isomerase, suggesting that these residues are crucial for the maintenance of biological activity. Two polymorphic sites were also identified, 489 A--,G and 1356 G--,C, which do not produce a change in the amino acid sequence. ...

Accepted name: fructose-bisphosphatase. Reaction: D-fructose 1,6-bisphosphate + H2O = D-fructose 6-phosphate + phosphate. For diagram of reaction click here, alternative click here.. Other name(s): hexose diphosphatase; FBPase; fructose 1,6-diphosphatase; fructose 1,6-diphosphate phosphatase; D-fructose 1,6-diphosphatase; fructose 1,6-bisphosphatase; fructose diphosphatase; fructose diphosphate phosphatase; fructose bisphosphate phosphatase; fructose 1,6-bisphosphate 1-phosphatase; fructose 1,6-bisphosphate phosphatase; hexose bisphosphatase; D-fructose-1,6-bisphosphate phosphatase. Systematic name: D-fructose-1,6-bisphosphate 1-phosphohydrolase. Comments: The animal enzyme also acts on sedoheptulose 1,7-bisphosphate.. Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9001-52-9. References:. 1. El-Badry, A.M. Hexosediphosphatase from spinach chloroplasts. Purification, crystallization and some properties. Biochim. Biophys. Acta 333 (1974) 366-377.. 2. ...

In this study, we provide the first demonstration for a role for the LPA signaling nexus in endogenous regulation of pathophysiologic vascular responses. Specifically, we report that mice deficient in 2 defined LPA receptors, LPA1 and LPA2, are protected from intimal hyperplasia in response to vascular injury through a mechanism that can primarily be accounted for by a decrease in the ability of LPA to promote migration of vascular SMCs. Interestingly, we also found that mice lacking LPA1 alone exhibited enhanced vascular injury responses, which correlated with an upregulation of a third LPA receptor, LPA3, and appeared to result from an enhanced LPA3-dependent vascular smooth muscle cell migratory response. These findings suggest that LPA is a relevant regulator of the murine vascular injury response and focus attention on possible sources of LPA at sites of vascular injury. We found that injury elevated vessel-associated levels of ATX, the lysophospholipase D responsible for generation of ...

Summary Changes in enzymes and metabolites of the carbohydrate metabolism in skeletal muscles were studied in mice after intracerebral inoculation of dengue type 2 virus. It was noted that lactic dehydrogenase, aldolase, phosphogluco-isomerase, phosphoglucomutase, GO-T and GP-T activity were enhanced initially by two- to three-fold, reaching a peak on day 5. As the illness appeared in mice, all the enzyme activities were lowered and were about three times less in the paralytic stage on the 8th day as compared to controls. Fructose-1,6-diphosphatase activity was increased on the 4th and 5th days but decreased later. Acid phosphatase increased abruptly from the 6th day while alkaline phosphatase activity was irregular. Creatine increased on the 4th and 5th days but diminished later. Glycogen decreased from the beginning and was lowest on the 5th day, but the levels increased later and were maximum in paralysed muscles. On the other hand, lactic acid began accumulating in the muscles and was maximum on the

Fructose is highly correlated with the development of diabetes, obesity and a metabolic syndrome. Fructose metabolism differs from glucose metabolism in that fructose causes the formation of uric acid. A chemical is acted upon by uric acid that causes a very rapid depletion of ATP, the main source of chemical energy for body cells. When the body senses the loss of stored ATP it signals for food intake to manufacture the ATP it senses it, the body , needs. This chemical is not subject to feedback inhibition such as is the case for glucose metabolism. This results in a very large ATP depletion. This cycle repeats itself and more food is taken in and the breakdown product are stored as fat. You, in other words, get fatter and fatter. Since the liver is the source for the majority of fructose metabolism the depletion of ATP, in the liver, has a direct effect on other liver metabolic procedures. An increase in uric acid formation takes place after a series of chemical changes in the liver. ...

Retroviral and lentiviral titration kits that measure virus titers using SYBR Green-based, real-time PCR. Viral copy numbers are determined by comparing the sample's Ct to a standard curve derived from a calibrated control template.