An imidazole derivative which is a metabolite of the antineoplastic agents BIC and DIC. By itself, or as the ribonucleotide, it is used as a condensation agent in the preparation of nucleosides and nucleotides. Compounded with orotic acid, it is used to treat liver diseases.
A PYRIDOXAL PHOSPHATE-containing enzyme that catalyzes the transfer of a formyl group from L-GLUTAMATE to N-formimidoyl-L-glutamate and TETRAHYDROFOLATE. This enzyme may also catalyze formyl transfer from 5-formyltetrahydrofolate to L-GLUTAMATE. This enzyme was formerly categorized as EC 2.1.2.6.
An enzyme that catalyzes the conversion of aminoimidazole-4-carboxamide ribonucleotide to 5-formyl-aminoimidazole-4-carboxamide ribonucleotide in the purine de novo synthesis pathway. It requires the cofactor N(10)-FORMYLTETRAHYDROFOLATE as the formyl donor.
Enzymes that catalyze the transfer of hydroxymethyl or formyl groups. EC 2.1.2.
Nucleotides in which the purine or pyrimidine base is combined with ribose. (Dorland, 28th ed)
Enzymes that catalyze the joining of two molecules by the formation of a carbon-nitrogen bond. EC 6.3.
An enzyme that catalyzes the transfer of a formyl group from N10-formyltetrahydrofolate to N1-(5-phospho-D-ribosyl)glycinamide to yield N2-formyl-N1-(5-phospho-D-ribosyl)glycinamide and tetrahydrofolate. It plays a role in the de novo purine biosynthetic pathway.
3-((4-Amino-2-methyl-5-pyrimidinyl)methyl)-5-(2- hydroxyethyl)-4-methylthiazolium chloride.
Enzymes that catalyze the joining of glutamine-derived ammonia and another molecule. The linkage is in the form of a carbon-nitrogen bond. EC 6.3.5.
A genus of large, brightly colored SPONGES in the family Agelasidae, possessing a skeleton of spongin fibers with a core of large spicules (megascleres).
A series of heterocyclic compounds that are variously substituted in nature and are known also as purine bases. They include ADENINE and GUANINE, constituents of nucleic acids, as well as many alkaloids such as CAFFEINE and THEOPHYLLINE. Uric acid is the metabolic end product of purine metabolism.
Compounds containing 1,3-diazole, a five membered aromatic ring containing two nitrogen atoms separated by one of the carbons. Chemically reduced ones include IMIDAZOLINES and IMIDAZOLIDINES. Distinguish from 1,2-diazole (PYRAZOLES).
Enzymes that catalyze the addition of a carboxyl group to a compound (carboxylases) or the removal of a carboxyl group from a compound (decarboxylases). EC 4.1.1.
A class of enzymes that catalyze the formation of a bond between two substrate molecules, coupled with the hydrolysis of a pyrophosphate bond in ATP or a similar energy donor. (Dorland, 28th ed) EC 6.
A subgenus of Salmonella containing several medically important serotypes. The habitat for the majority of strains is warm-blooded animals.
Nucleosides in which the purine or pyrimidine base is combined with ribose. (Dorland, 28th ed)
Catalyze the hydrolysis of nucleotides with the elimination of ammonia.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.

Absorption, metabolism, and excretion of 14C-temozolomide following oral administration to patients with advanced cancer. (1/623)

The purpose of this study is to characterize the absorption, metabolism, and excretion of carbon 14-labeled temozolomide (14C-TMZ) administered p.o. to adult patients with advanced solid malignancies. On day 1 of cycle 1, six patients received a single oral 200-mg dose of 14C-TMZ (70.2 microCi). Whole blood, plasma, urine, and feces were collected from days 1-8 and on day 14 of cycle 1. Total radioactivity was measured in all samples. TMZ, 5-(3-methyltriazen-1-yl)imidazole-4-carboxamide (MTIC), and 4-amino-5-imidazole-carboxamide (AIC) concentrations were determined in plasma, and urine and plasma samples were profiled for metabolite/degradation products. Maximum TMZ plasma concentrations were achieved between 0.33 to 2 h (mean, 1.2 h), and half-life, apparent volume of distribution, and oral clearance values averaged 1.9 h, 17 liters/m2, and 104 ml/min/m2, respectively. A first-order absorption, one-compartment linear model, which included first-order formation of MTIC from TMZ and elimination of MTIC via degradation to AIC, and a peripheral distribution compartment for AIC, adequately described the plasma TMZ, MTIC, and AIC concentrations. MTIC systemic clearance was estimated to be 5384 ml/min/m2, and the half-life was calculated to be 2.5 min. Metabolite profiles of plasma at 1 and 4 h after treatment showed that 14C-derived radioactivity was primarily associated with TMZ, and a smaller amount was attributed to AIC. Profiles of urine samples from 0-24 h revealed that 14C-TMZ-derived urinary radioactivity was primarily associated with unchanged drug (5.6%), AIC (12%), or 3-methyl-2,3-dihydro-4-oxoimidazo[5,1-d]tetrazine-8-carboxyl ic acid (2.3%). The recovered radioactive dose (39%) was principally eliminated in the urine (38%), and a small amount (0.8%) was excreted in the feces. TMZ exhibits rapid oral absorption and high systemic availability. The primary elimination pathway for TMZ is by pH-dependent degradation to MTIC and further degradation to AIC. Incomplete recovery of radioactivity may be explained by the incorporation of AIC into nucleic acids.  (+info)

Apoptosis induced by growth factor withdrawal in fibroblasts overproducing fructose 2,6-bisphosphate. (2/623)

Fructose 2,6-bisphosphate is a potent endogenous stimulator of glycolysis. A high aerobic glycolytic rate often correlates with increased cell proliferation. To investigate this relationship, we have produced clonal cell lines of Rat-1 fibroblasts that stably express transgenes coding for 6-phosphofructo-2-kinase, which catalyzes the synthesis of fructose 2,6-bisphosphate, or for fructose 2,6-bisphosphatase, which catalyzes its degradation. While serum deprivation in culture reduced the growth rate of control cells, it caused apoptosis in cells overproducing fructose 2,6-bisphosphate. Apoptosis was inhibited by 5-amino-4-imidazolecarboxamide riboside, suggesting that 5'-AMP-activated protein kinase interferes with this phenomenon.  (+info)

Effect of AMPK activation on muscle glucose metabolism in conscious rats. (3/623)

The effect of AMP-activated protein kinase (AMPK) activation on skeletal muscle glucose metabolism was examined in awake rats by infusing them with 5-aminoimidazole-4-carboxamide 1-beta-D-ribofuranoside (AICAR; 40 mg/kg bolus and 7.5 mg. kg-1. min-1 constant infusion) along with a variable infusion of glucose (49.1 +/- 2.4 micromol. kg-1. min-1) to maintain euglycemia. Activation of AMPK by AICAR caused 2-deoxy-D-[1,2-3H]glucose (2-DG) uptake to increase more than twofold in the soleus and the lateral and medial gastrocnemius compared with saline infusion and occurred without phosphatidylinositol 3-kinase activation. Glucose uptake was also assessed in vitro by use of the epitrochlearis muscle incubated either with AICAR (0.5 mM) or insulin (20 mU/ml) or both in the presence or absence of wortmannin (1.0 microM). AICAR and insulin increased muscle 2-DG uptake rates by approximately 2- and 2.7-fold, respectively, compared with basal rates. Combining AICAR and insulin led to a fully additive effect on muscle glucose transport activity. Wortmannin inhibited insulin-stimulated glucose uptake. However, neither wortmannin nor 8-(p-sulfophenyl)-theophylline (10 microM), an adenosine receptor antagonist, inhibited the AICAR-induced activation of glucose uptake. Electrical stimulation led to an about threefold increase in glucose uptake over basal rates, whereas no additive effect was found when AICAR and contractions were combined. In conclusion, the activation of AMPK by AICAR increases skeletal muscle glucose transport activity both in vivo and in vitro. This cellular pathway may play an important role in exercise-induced increase in glucose transport activity.  (+info)

5' AMP-activated protein kinase activation causes GLUT4 translocation in skeletal muscle. (4/623)

It has previously been reported that exercise causes an increase in glucose uptake in skeletal muscle and also an increase in 5' AMP-activated protein kinase (AMPK) activity. 5-Aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICA-riboside), an analog of adenosine, is taken up into cells and phosphorylated to form AICA-riboside monophosphate (ZMP), which can also activate AMPK. This study was designed to determine whether the increase in glucose uptake observed with AMPK activation by AICA-riboside is due to GLUT4 translocation from an intracellular location to the plasma membranes, similar to that seen in response to contraction. Rat hindlimbs were perfused with Krebs-Henseleit bicarbonate containing 4% bovine serum albumin, washed bovine erythrocytes, 8 mmol/l glucose, and +/-2 mmol/AICA-riboside or +/-60 nmol/l insulin. Perfusion medium containing AICA-riboside was found to significantly increase AMPK activity, glucose uptake, and GLUT4 translocation in skeletal muscle above basal levels. Insulin-perfused muscles showed significant increases in glucose uptake and GLUT4 translocation, but AMPK activation was not significantly changed from basal levels. These results provide evidence that the increased glucose uptake observed with AMPK activation by AICA-riboside in perfused rat hindlimb muscles is due to an increase in the translocation of GLUT4 to surface membranes.  (+info)

Translocation of myocardial GLUT-4 and increased glucose uptake through activation of AMPK by AICAR. (5/623)

Insulin increases glucose uptake through the translocation of GLUT-4 via a pathway mediated by phosphatidylinositol 3-kinase (PI3K). In contrast, myocardial glucose uptake during ischemia and hypoxia is stimulated by the translocation of GLUT-4 to the surface of cardiac myocytes through a PI3K-independent pathway that has not been characterized. AMP-activated protein kinase (AMPK) activity is also increased by myocardial ischemia, and we examined whether AMPK stimulates glucose uptake and GLUT-4 translocation. In isolated rat ventricular papillary muscles, 5-aminoimidazole-4-carboxyamide-1-beta-D-ribofuranoside (AICAR), an activator of AMPK, as well as cyanide-induced chemical hypoxia and insulin, increased 2-[(3)H]deoxyglucose uptake two- to threefold. Wortmannin, a PI3K inhibitor, did not affect either the AICAR- or the cyanide-stimulated increase in deoxyglucose uptake but eliminated the insulin-stimulated increase in deoxyglucose uptake. Immunofluorescence studies demonstrated translocation of GLUT-4 to the myocyte sarcolemma in response to stimulation with AICAR, cyanide, or insulin. Preincubation of papillary muscles with the kinase inhibitor iodotubercidin or adenine 9-beta-D-arabinofuranoside (araA), a precursor of araATP (a competitive inhibitor of AMPK), decreased AICAR- and cyanide-stimulated glucose uptake but did not affect basal or insulin-stimulated glucose uptake. In vivo infusion of AICAR caused myocardial AMPK activation and GLUT-4 translocation in the rat. We conclude that AMPK activation increases cardiac muscle glucose uptake through translocation of GLUT-4 via a pathway that is independent of PI3K. These findings suggest that AMPK activation may be important in ischemia-induced translocation of GLUT-4 in the heart.  (+info)

Improvement by 5-amino-4-imidazole carboxamide riboside of the contractile dysfunction that follows brief periods of ischemia through increases in ecto-5-nucleotidase activity and adenosine release in canine hearts. (6/623)

5-Amino-4-imidazole carboxamide (AICA) riboside increases adenosine release in ischemic myocardium, suggesting that AICA riboside improves contractile dysfunction. In 49 open-chest dogs, contractile function assessed by fractional shortening (FS) was observed 3 h after the onset of reperfusion following 15 min of occlusion of the left anterior descending coronary artery. During reperfusion, the treatment with AICA riboside increased adenosine concentration in the coronary venous blood (536+/-44 vs. 281+/-21 pmol/ml at 3 min of reperfusion, p<0.001) and peak coronary hyperemic flow (367+/-13 vs. 300+/-21 ml/100 g per min, p<0.001) when compared with the untreated group. FS at 3h of reperfusion increased in the AICA riboside group (21.1+/-2.3 vs. 12.8+/-0.6% in the untreated group, p<0.001). AICA riboside increased myocardial ecto-5'-nucleotidase activity. Administration of adenosine also augmented coronary hyperemic flow and increased FS to the levels of the AICA riboside group. Either 8-phenyltheophylline (an antagonist of adenosine receptors) or alpha,beta-methylene-adenosine 5'-diphosphate (an inhibitor of ecto-5'-nucleotidase) completely abolished the increased coronary hyperemic flow and improvements of myocardial contractile function due to AICA riboside. Thus it was concluded that AICA riboside improves the contractile dysfunction that follows a brief period of ischemia via adenosine-dependent mechanisms.  (+info)

Effect of methotrexate on blood purine and pyrimidine levels in patients with rheumatoid arthritis. (7/623)

OBJECTIVE: The mechanism of anti-inflammatory effects of methotrexate (MTX) at low dose may relate to a decrease in availability of the purine precursor or it may depend on accumulation of 5-aminoimidazole-4-carboxamide (AICAR) and the anti-inflammatory nucleoside adenosine. The aim of this study was to evaluate the possible mechanism of action by analysis of changes in blood concentrations of purine and pyrimidine metabolites during MTX treatment. METHODS: Venous blood samples were collected from rheumatoid arthritis patients before and at different times for up to 7 days after the start of MTX treatment. Whole blood concentrations of adenosine, uridine, hypoxanthine, uric acid and erythrocyte nucleotides were measured by HPLC. RESULTS: The initial blood adenosine concentration was 0.073 +/- 0.013 microM and no differences were observed during MTX treatment. However, a decrease in uric acid concentration was observed from 205.5+/-13.5 to 160. 9+/-13.5 microM (P<0.05) within 24 h after MTX administration. The hypoxanthine concentration decreased in parallel with uric acid, while the uridine concentration decreased 48 h after MTX administration. No accumulation of AICAR-triphosphate (ZTP) was observed in the erythrocytes. CONCLUSIONS: MTX decreases circulating purine and pyrimidine concentrations, and their availability for DNA and RNA synthesis, which may affect immune cell proliferation and protein (cytokine) expression. The absence of adenosine concentration changes and lack of ZTP formation is evidence against an AICAR/adenosine mechanism, although localized adenosine concentration changes cannot be excluded.  (+info)

Chronic activation of 5'-AMP-activated protein kinase increases GLUT-4, hexokinase, and glycogen in muscle. (8/623)

This study was designed to determine whether chronic chemical activation of AMP-activated protein kinase (AMPK) would increase glucose transporter GLUT-4 and hexokinase in muscles similarly to periodic elevation of AMPK that accompanies endurance exercise training. The adenosine analog, 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR), has previously been shown to be taken up by cells and phosphorylated to form a compound (5-aminoimidazole-4-carboxamide ribonucleotide) that mimics the effect of AMP on AMPK. A single injection of AICAR resulted in a marked increase in AMPK in epitrochlearis and gastrocnemius/plantaris muscles 60 min later. When rats were injected with AICAR (1 mg/g body wt) for 5 days in succession and were killed 1 day after the last injection, GLUT-4 was increased by 100% in epitrochlearis muscle and by 60% in gastrocnemius muscle in response to AICAR. Hexokinase was also increased approximately 2. 5-fold in the gastrocnemius/plantaris. Gastrocnemius glycogen content was twofold higher in AICAR-treated rats than in controls. Chronic chemical activation of AMPK, therefore, results in increases in GLUT-4 protein, hexokinase activity, and glycogen, similarly to those induced by endurance training.  (+info)

Aminoimidazole carboxamide is a compound that is involved in the metabolic pathways of nucleotide synthesis in cells. It is also known as AICA ribonucleotide, and is a precursor to an important energy molecule in the body called adenosine triphosphate (ATP).

In medical terms, aminoimidazole carboxamide is sometimes used as a research tool to study cellular metabolism and has been investigated for its potential therapeutic use in various conditions such as neurodegenerative disorders and ischemia-reperfusion injury. However, it is not commonly used as a medication in clinical practice.

Glutamate Formimidoyltransferase (FTCD) is an enzyme that plays a role in the metabolism of histidine, one of the essential amino acids. The enzyme catalyzes the transfer of a formimidoyl group from the derivative of histidine, formiminoglutamate (FIGLU), to the amino group of glutamate, forming formiminoglutamic acid and freeing up tetrahydrofolate in the process.

The reaction catalyzed by FTCD is as follows:

formiminoglutamate + glutamate -> formiminoglutamic acid + glutamate

This enzyme is found in various organisms, including humans, and is located in the mitochondria. A deficiency in FTCD can lead to an accumulation of FIGLU and may be associated with certain neurological disorders.

Phosphoribosylaminoimidazolecarboxamide formyltransferase (AIRFT) is an enzyme involved in the purine nucleotide biosynthesis pathway. The systematic medical name for this enzyme is "phosphoribosylaminoimidazole carboxamide formyltransferase, IMP cyclohydrolase, and GMP synthase."

The primary function of AIRFT is to catalyze the conversion of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) to formylated AICAR (FAICAR), which is an essential step in the synthesis of inosine monophosphate (IMP). IMP is a key precursor for the biosynthesis of both adenine and guanine nucleotides.

The enzyme's activity can be measured by determining the rate of conversion of AICAR to FAICAR, which requires the presence of 10-formyltetrahydrofolate (10-Formyl-THF) as a cofactor. Deficiency in this enzyme can lead to impaired purine synthesis and may result in various clinical manifestations such as developmental delay, neurological symptoms, and immunodeficiency.

Hydroxymethyl and Formyl Transferases are a class of enzymes that catalyze the transfer of hydroxymethyl or formyl groups from one molecule to another. These enzymes play important roles in various metabolic pathways, including the synthesis and modification of nucleotides, amino acids, and other biomolecules.

One example of a Hydroxymethyl Transferase is DNA methyltransferase (DNMT), which catalyzes the transfer of a methyl group from S-adenosylmethionine (SAM) to the 5-carbon of cytosine residues in DNA, forming 5-methylcytosine. This enzyme can also function as a Hydroxymethyl Transferase by catalyzing the transfer of a hydroxymethyl group from SAM to cytosine residues, forming 5-hydroxymethylcytosine.

Formyl Transferases are another class of enzymes that catalyze the transfer of formyl groups from one molecule to another. One example is formyltransferase domain containing protein 1 (FTCD1), which catalyzes the transfer of a formyl group from 10-formyltetrahydrofolate to methionine, forming N5-formiminotetrahydrofolate and methionine semialdehyde.

These enzymes are essential for maintaining proper cellular function and are involved in various physiological processes, including gene regulation, DNA repair, and metabolism. Dysregulation of these enzymes has been implicated in several diseases, including cancer, neurological disorders, and cardiovascular disease.

Ribonucleotides are organic compounds that consist of a ribose sugar, a phosphate group, and a nitrogenous base. They are the building blocks of RNA (ribonucleic acid), one of the essential molecules in all living organisms. The nitrogenous bases found in ribonucleotides include adenine, uracil, guanine, and cytosine. These molecules play crucial roles in various biological processes, such as protein synthesis, gene expression, and cellular energy production. Ribonucleotides can also be involved in cell signaling pathways and serve as important cofactors for enzymatic reactions.

Carbon-Nitrogen (C-N) ligases are a class of enzymes that catalyze the joining of a carbon atom from a donor molecule to a nitrogen atom in an acceptor molecule through a process called ligase reaction. This type of enzyme plays a crucial role in various biological processes, including the biosynthesis of amino acids, nucleotides, and other biomolecules that contain both carbon and nitrogen atoms.

C-N ligases typically require ATP or another energy source to drive the reaction forward, as well as cofactors such as metal ions or vitamins to facilitate the chemical bond formation between the carbon and nitrogen atoms. The specificity of C-N ligases varies depending on the enzyme, with some acting only on specific donor and acceptor molecules while others have broader substrate ranges.

Examples of C-N ligases include glutamine synthetase, which catalyzes the formation of glutamine from glutamate and ammonia, and asparagine synthetase, which catalyzes the formation of asparagine from aspartate and ammonia. Understanding the function and regulation of C-N ligases is important for understanding various biological processes and developing strategies to modulate them in disease states.

Phosphoribosylglycinamide formyltransferase (PGTF) is an enzyme involved in the biosynthesis of purine nucleotides, which are essential components of DNA and RNA. The systematic medical definition of PGTF is:

"An enzyme that catalyzes the transfer of a formyl group from 10-formyltetrahydrofolate to the amino group of phosphoribosylglycinamide, forming N-formylphosphoribosylglycinamide and tetrahydrofolate as byproducts. This reaction is the fourth step in the de novo synthesis pathway of purine nucleotides."

PGTF's gene name is GART (Glycinamide Ribonucleotide Transformylase), and it is located on human chromosome 10q24.32-q25.1. Mutations in the GART gene can lead to a rare autosomal recessive disorder called Lesch-Nyhan syndrome, which is characterized by hyperuricemia, neurological symptoms, and self-mutilating behavior.

Thiamine, also known as vitamin B1, is a water-soluble vitamin that plays a crucial role in certain metabolic reactions, particularly in the conversion of carbohydrates into energy in the body. It is essential for the proper functioning of the heart, nerves, and digestive system. Thiamine acts as a cofactor for enzymes involved in the synthesis of neurotransmitters and the metabolism of carbohydrates, lipids, and proteins. Deficiency in thiamine can lead to serious health complications, such as beriberi (a disease characterized by peripheral neuropathy, muscle wasting, and heart failure) and Wernicke-Korsakoff syndrome (a neurological disorder often seen in alcoholics due to chronic thiamine deficiency). Thiamine is found in various foods, including whole grains, legumes, pork, beef, and fortified foods.

Carbon-Nitrogen (C-N) ligases with glutamine as amide-N-donor are a class of enzymes that catalyze the joining of a carbon atom and a nitrogen atom from different molecules, with glutamine serving as the nitrogen donor. The reaction specifically involves the transfer of the amide nitrogen from glutamine to a carbonyl carbon atom, resulting in the formation of a new C-N bond.

This type of enzyme is involved in various biological processes, including the biosynthesis of amino acids, nucleotides, and other biomolecules. The reaction catalyzed by these enzymes often requires ATP as an energy source to drive the formation of the new bond.

An example of a C-N ligase with glutamine as amide-N-donor is glutamine synthetase, which catalyzes the formation of glutamine from glutamate and ammonia using ATP as an energy source. The enzyme uses the amide nitrogen of glutamine to transfer the nitrogen atom to the carbonyl carbon of glutamate, forming a new C-N bond in the process.

"Agelas" is a genus of demosponges, also known as marine sponges, that belong to the family Agelasidae. These sponges are commonly found in tropical and subtropical waters around the world. They are known for their distinctive skeletal structures, which are made up of fused spicules (small, needle-like structures) that form a rigid framework. Some species of Agelas contain compounds with potential medicinal properties, such as anti-inflammatory and antiviral agents. However, there is no specific medical definition or use of the term "Agelas."

Purines are heterocyclic aromatic organic compounds that consist of a pyrimidine ring fused to an imidazole ring. They are fundamental components of nucleotides, which are the building blocks of DNA and RNA. In the body, purines can be synthesized endogenously or obtained through dietary sources such as meat, seafood, and certain vegetables.

Once purines are metabolized, they are broken down into uric acid, which is excreted by the kidneys. Elevated levels of uric acid in the body can lead to the formation of uric acid crystals, resulting in conditions such as gout or kidney stones. Therefore, maintaining a balanced intake of purine-rich foods and ensuring proper kidney function are essential for overall health.

Imidazoles are a class of heterocyclic organic compounds that contain a double-bonded nitrogen atom and two additional nitrogen atoms in the ring. They have the chemical formula C3H4N2. In a medical context, imidazoles are commonly used as antifungal agents. Some examples of imidazole-derived antifungals include clotrimazole, miconazole, and ketoconazole. These medications work by inhibiting the synthesis of ergosterol, a key component of fungal cell membranes, leading to increased permeability and death of the fungal cells. Imidazoles may also have anti-inflammatory, antibacterial, and anticancer properties.

Carboxy-lyases are a class of enzymes that catalyze the removal of a carboxyl group from a substrate, often releasing carbon dioxide in the process. These enzymes play important roles in various metabolic pathways, such as the biosynthesis and degradation of amino acids, sugars, and other organic compounds.

Carboxy-lyases are classified under EC number 4.2 in the Enzyme Commission (EC) system. They can be further divided into several subclasses based on their specific mechanisms and substrates. For example, some carboxy-lyases require a cofactor such as biotin or thiamine pyrophosphate to facilitate the decarboxylation reaction, while others do not.

Examples of carboxy-lyases include:

1. Pyruvate decarboxylase: This enzyme catalyzes the conversion of pyruvate to acetaldehyde and carbon dioxide during fermentation in yeast and other organisms.
2. Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO): This enzyme is essential for photosynthesis in plants and some bacteria, as it catalyzes the fixation of carbon dioxide into an organic molecule during the Calvin cycle.
3. Phosphoenolpyruvate carboxylase: Found in plants, algae, and some bacteria, this enzyme plays a role in anaplerotic reactions that replenish intermediates in the citric acid cycle. It catalyzes the conversion of phosphoenolpyruvate to oxaloacetate and inorganic phosphate.
4. Aspartate transcarbamylase: This enzyme is involved in the biosynthesis of pyrimidines, a class of nucleotides. It catalyzes the transfer of a carboxyl group from carbamoyl aspartate to carbamoyl phosphate, forming cytidine triphosphate (CTP) and fumarate.
5. Urocanase: Found in animals, this enzyme is involved in histidine catabolism. It catalyzes the conversion of urocanate to formiminoglutamate and ammonia.

Ligases are a group of enzymes that catalyze the formation of a covalent bond between two molecules, usually involving the joining of two nucleotides in a DNA or RNA strand. They play a crucial role in various biological processes such as DNA replication, repair, and recombination. In DNA ligases, the enzyme seals nicks or breaks in the phosphodiester backbone of the DNA molecule by catalyzing the formation of an ester bond between the 3'-hydroxyl group and the 5'-phosphate group of adjacent nucleotides. This process is essential for maintaining genomic integrity and stability.

"Salmonella enterica" is a gram-negative, facultatively anaerobic bacterium that belongs to the family Enterobacteriaceae. It is a common cause of foodborne illnesses worldwide, often resulting in gastroenteritis, which is characterized by symptoms such as diarrhea, abdominal cramps, fever, and vomiting.

"Salmonella enterica" is further divided into several serovars or subspecies, with some of the most common ones causing human illness being Typhimurium and Enteritidis. These bacteria are typically transmitted to humans through contaminated food or water sources, such as raw or undercooked meat, poultry, eggs, and dairy products.

Once ingested, "Salmonella enterica" can colonize the gastrointestinal tract and release endotoxins that cause inflammation and damage to the intestinal lining. In some cases, the bacteria can spread to other parts of the body, leading to more severe and potentially life-threatening infections, particularly in individuals with weakened immune systems.

Preventing "Salmonella enterica" infections involves proper food handling and preparation practices, such as washing hands and surfaces thoroughly, cooking meats and eggs to appropriate temperatures, and avoiding cross-contamination between raw and cooked foods.

Ribonucleosides are organic compounds that consist of a nucleoside bound to a ribose sugar. Nucleosides are formed when a nitrogenous base (such as adenine, guanine, uracil, cytosine, or thymine) is attached to a sugar molecule (either ribose or deoxyribose) via a beta-glycosidic bond. In the case of ribonucleosides, the sugar component is D-ribose. Ribonucleosides play important roles in various biological processes, particularly in the storage, transfer, and expression of genetic information within cells. When ribonucleosides are phosphorylated, they become the building blocks of RNA (ribonucleic acid), a crucial biomolecule involved in protein synthesis and other cellular functions. Examples of ribonucleosides include adenosine, guanosine, uridine, cytidine, and inosine.

Nucleotide deaminases are a group of enzymes that catalyze the removal of an amino group (-NH2) from nucleotides, which are the building blocks of DNA and RNA. Specifically, these enzymes convert cytidine or adenosine to uridine or inosine, respectively, by removing an amino group from the corresponding nitrogenous base (cytosine or adenine).

There are several types of nucleotide deaminases that differ in their substrate specificity and cellular localization. For example, some enzymes deaminate DNA or RNA directly, while others act on free nucleotides or nucleosides. Nucleotide deaminases play important roles in various biological processes, including the regulation of gene expression, immune response, and DNA repair.

Abnormal activity or mutations in nucleotide deaminases have been associated with several human diseases, such as cancer, autoimmune disorders, and viral infections. Therefore, understanding the function and regulation of these enzymes is crucial for developing new therapeutic strategies to treat these conditions.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

5(4)-aminoimidazole-4(5)-carboxamide (AICA and TAICA) is an important precursor for the synthesis of purines in general and of ... Variable-temperature [superscript 1]H-NMR and AB initio study of 5-amino-imidazole-4-carboxamide (AICA) : competing paths for ...
5-Aminoimidazole-4-carboxamide is a ubiquitous metabolite and an intermediate in purine biosynthesis of compounds such as ... Derivatives of 5-aminoimidazole-4-carboxamide have broad biological effects as antitumor, antiviral, antidiabetic and anti- ... The AMPK agonist 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), but not metformin, prevents inflammation-associated ...
August 2007). "5-aminoimidazole-4-carboxamide 1-beta-D-ribofuranoside acutely stimulates skeletal muscle 2-deoxyglucose uptake ... Acadesine (INN), also known as 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside, AICA-riboside, and AICAR, is an AMP- ... Cronstein BN, Kamen BA (December 2007). "5-aminoimidazole-4-carboxamide-1-beta-4-ribofuranoside (AICA-riboside) as a targeting ... Corton JM, Gillespie JG, Hawley SA, Hardie DG (April 1995). "5-aminoimidazole-4-carboxamide ribonucleoside. A specific method ...
5-Aminoimidazole-4-carboxamide 1-ß-D-ribofuranoside , CAS 2627-69-2 , J&K Scientific ...
Enhancement of insulin-mediated rat muscle glucose uptake and microvascular perfusion by 5-aminoimidazole-4-carboxamide-1-β-d- ... Enhancement of insulin-mediated rat muscle glucose uptake and microvascular perfusion by 5-aminoimidazole-4-carboxamide-1-β-D- ... Enhancement of insulin-mediated rat muscle glucose uptake and microvascular perfusion by 5-aminoimidazole-4-carboxamide-1-β-d- ...
In the present study, the effect of 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) on long-chain fatty acid oxidation by ... The effect of 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) on fatty acid oxidation in hepatocytes isolated from ...
5-aminoimidazole-4-carboxamide riboside) alone also increased GLUT3 surface expression, with a hyperpolarization of Δψm evident ... 5-aminoimidazole-4-carboxamide riboside (AICAR) was obtained from Cell Signaling. Compound C and KN93 (water-soluble) obtained ...
A: AICAR, 5-aminoimidazole-4-carboxamide ribonucleotide; AMPK, AMP-activated protein kinase; GAPDH, glyceraldehyde-3-phosphate ... However, it is known that long-lasting polyglutamate metabolites of MTX inhibit 5-aminoimidazole-4-carboxamide ribonucleotide ( ... Methotrexate enhances the antianabolic and antiproliferative effects of 5-aminoimidazole-4-carboxamide riboside. Mol Cancer ... MTX increases intracellular accumulation of adenosine monophosphate (AMP) and 5-aminoimidazole-4-carboxamide ribonucleotide ...
AICAR T′ase, 5-aminoimidazole-4-carboxamide ribonucleotide transformylase. *ALL, acute lymphoblastic leukaemia ...
Name: 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase. Synonyms: 2610509C24Rik. Type: Gene ...
Protein Phosphoribosylformimino-5-aminoimidazole carboxamide ribotite isomerase HisA [51368] (2 species). *. Species Thermotoga ... d1qo2b_ c.1.2.1 (B:) Phosphoribosylformimino-5-aminoimidazole carboxamide ribotite isomerase HisA {Thermotoga maritima [TaxId: ...
ABBREVIATIONS: AMPK, AMP-activated protein kinase; AICAR, 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside; ACC, acetyl-CoA ...
Adenylosuccinate lyase converts a molecule called succinylaminoimidazole carboxamide ribotide (SAICAR) to aminoimidazole ... which are converted through a different reaction to succinylaminoimidazole carboxamide riboside (SAICAr) and succinyladenosine ... feature that can help with diagnosis of this condition is the presence of chemicals called succinylaminoimidazole carboxamide ... carboxamide ribotide (AICAR) and converts succinyladenosine monophosphate (SAMP) to adenosine monophosphate (AMP). ...
5-aminoimidazole-4-carboxamide ribonucleotide), a chemical AMPK activator, increases HGP without changing the plasma levels of ...
The second last step is catalysed by 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase EC 2.1.2.3 (AICARFT), this ... The second last step is catalysed by 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase (AICARFT), this enzyme ... Molecular cloning and expression of a rat cDNA encoding 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP ... The cDNA of a 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (AICARFT/IMPCHase) was ...
Aminoimidazole Carboxamide Preferred Term Term UI T001853. Date01/01/1999. LexicalTag NON. ThesaurusID NLM (1978). ... Aminoimidazole Carboxamide Preferred Concept UI. M0000949. Registry Number. 360-97-4. Scope Note. An imidazole derivative which ... Aminoimidazole Carboxamide. Tree Number(s). D03.383.129.308.030. Unique ID. D000620. RDF Unique Identifier. http://id.nlm.nih. ... 1H-Imidazole-4-carboxamide, 5-amino-. Previous Indexing. Imidazoles (1966-1977). Public MeSH Note. 91; was see under IMIDAZOLES ...
5-Aminoimidazole-4-carboxamide riboside (AICAR), an agent with diverse pharmacological properties, augments transport of ...
5- Aminoimidazole- 4- carboxamide- 1- β- D- ribofuranoside ( AICAR / Acadesine / Z-riboside ). ... Res., 84, 614 - 625 (2006), "5-Aminoimidazole-4-Carboxamide-1-Beta-4-Ribofuranoside Attenuates Experimental Autoimmune ... "Inhibition of Insulin-Stimulated Glycogen Synthesis by 5-Aminoimidasole-4-Carboxamide-1-Beta-D-Ribofuranoside-Induced Adenosine ...
AICAr (5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside, commonly referred to as AICAR) is an adenosine monophosphate- ...
P. A. Lochhead, I. P. Salt, K. S. Walker, D. G. Hardie, and C. Sutherland, "5-Aminoimidazole-4-carboxamide riboside mimics the ...
Genetic evidence for 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) as a negative effector of cytochrome terminal ... Genetic evidence for 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) as a negative effector of cytochrome terminal ...
... modulation by 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR). Biochem J. 2004;378(3):769-78. ...
MTIC is further hydrolyzed to 5-amino-imidazole-4-carboxamide (AIC), which is known to be an intermediate in purine and nucleic ... The chemical name of temozolomide, USP is 3,4-dihydro-3-methyl-4-oxoimidazo[5,1-d]-as-tetrazine-8-carboxamide. The structural ... The prodrug, temozolomide, USP, is rapidly hydrolyzed to the active 5-(3-methyltriazen-1-yl) imidazole-4-carboxamide (MTIC) at ... imidazole-4-carboxamide (MTIC). The cytotoxicity of MTIC is thought to be primarily due to alkylation of DNA. Alkylation ( ...
5-Aminoimidazole-4-carboxamide riboside sensitizes TRAIL- and TNFalpha-induced cytotoxicity in colon cancer cells through AMP- ... 5-aminoimidazole-4-carboxyamide ribonucleoside) was obtained from Toronto Research Chemicals Inc., and compound C was bought ... Gene silencing of MKP-1 increased STAT1 phosphorylation and prevented 5-aminoimidazole-4-carboxyamide ribonucleoside-reduced ...
In this paper, we studied the effects of 5-aminoimidazole-4-carboxamide-1-ß-riboside (AICAR), an activator of AMP-activated ... 5-Aminoimidazole-4-carboxyamide ribonucleoside induces G(1)/S arrest and Nanog downregulation via p53 and enhances erythroid ... by using 5-aminoimidazole-4-carboxyamide ribonucleoside (AICAR) as an activator of AMPK. We demonstrate that AICAR treatment ...
5-Aminoimidazole-4-carboxamide 1-β-D-ribofuranoside.. References. *. Hitron A, Adams V, Talbert J, Steinke D: The influence of ...
5-amino-imidazole-4-carboxamide-1-β-d-ribofuranoside) activation of AMPK signaling.. Conclusions: These data demonstrate that ...
  • The AMPK agonist 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), but not metformin, prevents inflammation-associated cachectic muscle wasting. (bioaustralis.com)
  • MTX increases intracellular accumulation of adenosine monophosphate (AMP) and 5-aminoimidazole-4-carboxamide ribonucleotide which activates AMP-activated protein kinase (AMPK). (bmj.com)
  • The second last step is catalysed by 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase (AICARFT), this enzyme catalyses the formylation of AICAR with 10-formyl-tetrahydrofolate to yield FAICAR and tetrahydrofolate. (embl-heidelberg.de)
  • The last step is catalysed by IMP (Inosine monophosphate) cyclohydrolase (IMPCHase), cyclizing FAICAR (5-formylaminoimidazole-4-carboxamide ribonucleotide) to IMP. (embl-heidelberg.de)
  • Molecular cloning and expression of a rat cDNA encoding 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase. (embl-heidelberg.de)
  • The cDNA of a 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (AICARFT/IMPCHase) was isolated from rat liver RNA by reverse transcription and the polymerase chain reaction (PCR). (embl-heidelberg.de)
  • The human purH gene product, 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase. (embl-heidelberg.de)
  • We report here the cloning and sequencing of the cDNA, purification, steady state kinetic analysis, and truncation mapping studies of the human 5-aminoimidazole- 4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (AICARFT/IMPCHase). (embl-heidelberg.de)
  • AICAR or 5-Aminoimidazole-4-carboxamide ribonucleotide, is a synthetic adenosine monophosphate analog. (biotechpeptides.com)
  • It blocks purine synthesis and 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), thus increasing anti-inflammatory adenosine concentration at sites of inflammation. (medscape.com)
  • Acadesine (INN), also known as 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside, AICA-riboside, and AICAR, is an AMP-activated protein kinase activator which is used for the treatment of acute lymphoblastic leukemia and may have applications in treating other disorders such as diabetes. (wikipedia.org)
  • In the present study, the effect of 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) on long-chain fatty acid oxidation by hepatocytes isolated from suckled neonatal pig liver (a low ketogenic and lipogen. (biomedcentral.com)
  • Interestingly, pharmacological activation of AMPK with AICAR (5-aminoimidazole-4-carboxamide riboside) alone also increased GLUT3 surface expression, with a hyperpolarization of Δψ m evident in many neurons. (jneurosci.org)
  • Adenylosuccinate lyase converts a molecule called succinylaminoimidazole carboxamide ribotide (SAICAR) to aminoimidazole carboxamide ribotide (AICAR) and converts succinyladenosine monophosphate (SAMP) to adenosine monophosphate (AMP). (medlineplus.gov)
  • Overexpression of SOCS3 via adenovirus-mediated infection in lean myotubes to a similar degree as observed in obese myotubes prevented leptin but not AICAR (5-amino-imidazole-4-carboxamide-1-β-d-ribofuranoside) activation of AMPK signaling. (mcmaster.ca)
  • Additionally, AICAR apparently increased the levels of myocardial 5-aminoimidazole-4-carboxamide 1-beta-d-ribofuranotide (ZMP), which is the active intracellular form of AICAR. (biotechpeptides.com)
  • Achetez AICAR en ligne avec la plus haute qualite a un prix d'aubaine dans notre e-shop. (northshorecorvettes.com)
  • 5-aminoimidazole-4-carboxamide-1-beta-4-ribofuranoside (AICA-riboside) as a targeting agent for therapy of patients with acute lymphoblastic leukemia: are we there and are there pitfalls? (wikipedia.org)
  • A key feature that can help with diagnosis of this condition is the presence of chemicals called succinylaminoimidazole carboxamide riboside (SAICAr) and succinyladenosine (S-Ado) in body fluids. (medlineplus.gov)
  • Reduced function of this enzyme leads to buildup of SAICAR and SAMP, which are converted through a different reaction to succinylaminoimidazole carboxamide riboside (SAICAr) and succinyladenosine (S-Ado). (medlineplus.gov)
  • 5(4)-aminoimidazole-4(5)-carboxamide (AICA and TAICA) is an important precursor for the synthesis of purines in general and of the nucleobases adenine and guanine in particular. (umsystem.edu)
  • 5-Aminoimidazole-4-carboxamide is a ubiquitous metabolite and an intermediate in purine biosynthesis of compounds such as acadesine and gancyclovir. (bioaustralis.com)
  • Gene silencing of MKP-1 increased STAT1 phosphorylation and prevented 5-aminoimidazole-4-carboxyamide ribonucleoside-reduced STAT1 phosphorylation. (diabetesjournals.org)
  • 18. 5-aminoimidazole-4-carboxamide ribonucleoside. (nih.gov)
  • Cloning and molecular characterization of the Nicotiana tabacum purH cDNA encoding 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/inosine monophosphate cyclohydrolase. (mpg.de)
  • A key feature that can help with diagnosis of this condition is the presence of chemicals called succinylaminoimidazole carboxamide riboside (SAICAr) and succinyladenosine (S-Ado) in body fluids. (medlineplus.gov)
  • Reduced function of this enzyme leads to buildup of SAICAR and SAMP, which are converted through a different reaction to succinylaminoimidazole carboxamide riboside (SAICAr) and succinyladenosine (S-Ado). (medlineplus.gov)
  • The diagnosis of ADSL deficiency is based on the detection of dephosphorylated SAICAR and S-AMP products, that is, S-Ado (succinyladenosine) and SAICAr (succinylaminoimidazole carboxamide riboside). (bmj.com)
  • An enzyme that catalyzes the conversion of aminoimidazole-4-carboxamide ribonucleotide to 5-formyl-aminoimidazole-4-carboxamide ribonucleotide in the purine de novo synthesis pathway. (nih.gov)
  • 2. 5-Aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside inhibits cancer cell proliferation in vitro and in vivo via AMP-activated protein kinase. (nih.gov)
  • 17. Inhibition of hepatic phosphatidylcholine synthesis by 5-aminoimidazole-4-carboxamide-1-beta-4-ribofuranoside is independent of AMP-activated protein kinase activation. (nih.gov)