A natural product that has been considered as a growth factor for some insects.
Compounds based on pyrazino[2,3-d]pyrimidine which is a pyrimidine fused to a pyrazine, containing four NITROGEN atoms.
Compounds based on 2-amino-4-hydroxypteridine.
A pteridine derivative present in body fluids; elevated levels result from immune system activation, malignant disease, allograft rejection, and viral infections. (From Stedman, 26th ed) Neopterin also serves as a precursor in the biosynthesis of biopterin.
(GTP cyclohydrolase I) or GTP 7,8-8,9-dihydrolase (pyrophosphate-forming) (GTP cyclohydrolase II). An enzyme group that hydrolyzes the imidazole ring of GTP, releasing carbon-8 as formate. Two C-N bonds are hydrolyzed and the pentase unit is isomerized. This is the first step in the synthesis of folic acid from GTP. EC 3.5.4.16 (GTP cyclohydrolase I) and EC 3.5.4.25 (GTP cyclohydrolase II).
An enzyme that catalyzes the reduction of 6,7-dihydropteridine to 5,6,7,8-tetrahydropteridine in the presence of NADP+. Defects in the enzyme are a cause of PHENYLKETONURIA II. Formerly listed as EC 1.6.99.7.
Enzymes that catalyze the cleavage of a phosphorus-oxygen bond by means other than hydrolysis or oxidation. EC 4.6.
A group of autosomal recessive disorders marked by a deficiency of the hepatic enzyme PHENYLALANINE HYDROXYLASE or less frequently by reduced activity of DIHYDROPTERIDINE REDUCTASE (i.e., atypical phenylketonuria). Classical phenylketonuria is caused by a severe deficiency of phenylalanine hydroxylase and presents in infancy with developmental delay; SEIZURES; skin HYPOPIGMENTATION; ECZEMA; and demyelination in the central nervous system. (From Adams et al., Principles of Neurology, 6th ed, p952).
A condition characterized by focal DYSTONIA that progresses to involuntary spasmodic contractions of the muscles of the legs, trunk, arms, and face. The hands are often spared, however, sustained axial and limb contractions may lead to a state where the body is grossly contorted. Onset is usually in the first or second decade. Familial patterns of inheritance, primarily autosomal dominant with incomplete penetrance, have been identified. (Adams et al., Principles of Neurology, 6th ed, p1078)
A folic acid derivative used as a rodenticide that has been shown to be teratogenic.
An enzyme of the oxidoreductase class that catalyzes the formation of L-TYROSINE, dihydrobiopterin, and water from L-PHENYLALANINE, tetrahydrobiopterin, and oxygen. Deficiency of this enzyme may cause PHENYLKETONURIAS and PHENYLKETONURIA, MATERNAL. EC 1.14.16.1.
An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.
A form of gram-negative meningitis that tends to occur in neonates, in association with anatomical abnormalities (which feature communication between the meninges and cutaneous structures) or as OPPORTUNISTIC INFECTIONS in association with IMMUNOLOGIC DEFICIENCY SYNDROMES. In premature neonates the clinical presentation may be limited to ANOREXIA; VOMITING; lethargy; or respiratory distress. Full-term infants may have as additional features FEVER; SEIZURES; and bulging of the anterior fontanelle. (From Menkes, Textbook of Child Neurology, 5th ed, pp398-400)
The immediate precursor in the biosynthesis of SEROTONIN from tryptophan. It is used as an antiepileptic and antidepressant.
Purine bases related to hypoxanthine, an intermediate product of uric acid synthesis and a breakdown product of adenine catabolism.
An NADPH-dependent enzyme that catalyzes the conversion of L-ARGININE and OXYGEN to produce CITRULLINE and NITRIC OXIDE.
A subclass of enzymes which includes all dehydrogenases acting on primary and secondary alcohols as well as hemiacetals. They are further classified according to the acceptor which can be NAD+ or NADP+ (subclass 1.1.1), cytochrome (1.1.2), oxygen (1.1.3), quinone (1.1.5), or another acceptor (1.1.99).
A method of measuring the effects of a biologically active substance using an intermediate in vivo or in vitro tissue or cell model under controlled conditions. It includes virulence studies in animal fetuses in utero, mouse convulsion bioassay of insulin, quantitation of tumor-initiator systems in mouse skin, calculation of potentiating effects of a hormonal factor in an isolated strip of contracting stomach muscle, etc.
An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of TETRAHYDROFOLATE DEHYDROGENASE and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA.
A CALCIUM-dependent, constitutively-expressed form of nitric oxide synthase found primarily in NERVE TISSUE.
A CALCIUM-dependent, constitutively-expressed form of nitric oxide synthase found primarily in ENDOTHELIAL CELLS.
A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
An enzyme of the oxidoreductase class that catalyzes the reaction 7,8-dihyrofolate and NADPH to yield 5,6,7,8-tetrahydrofolate and NADPH+, producing reduced folate for amino acid metabolism, purine ring synthesis, and the formation of deoxythymidine monophosphate. Methotrexate and other folic acid antagonists used as chemotherapeutic drugs act by inhibiting this enzyme. (Dorland, 27th ed) EC 1.5.1.3.
Highly reactive compounds produced when oxygen is reduced by a single electron. In biological systems, they may be generated during the normal catalytic function of a number of enzymes and during the oxidation of hemoglobin to METHEMOGLOBIN. In living organisms, SUPEROXIDE DISMUTASE protects the cell from the deleterious effects of superoxides.
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).

L-Ascorbic acid potentiates nitric oxide synthesis in endothelial cells. (1/830)

Ascorbic acid has been shown to enhance impaired endothelium-dependent vasodilation in patients with atherosclerosis by a mechanism that is thought to involve protection of nitric oxide (NO) from inactivation by free oxygen radicals. The present study in human endothelial cells from umbilical veins and coronary arteries investigates whether L-ascorbic acid additionally affects cellular NO synthesis. Endothelial cells were incubated for 24 h with 0.1-100 microM ascorbic acid and were subsequently stimulated for 15 min with ionomycin (2 microM) or thrombin (1 unit/ml) in the absence of extracellular ascorbate. Ascorbate pretreatment led to a 3-fold increase of the cellular production of NO measured as the formation of its co-product citrulline and as the accumulation of its effector molecule cGMP. The effect was saturated at 100 microM and followed a similar kinetics as seen for the uptake of ascorbate into the cells. The investigation of the precursor molecule L-gulonolactone and of different ascorbic acid derivatives suggests that the enediol structure of ascorbate is essential for its effect on NO synthesis. Ascorbic acid did not induce the expression of the NO synthase (NOS) protein nor enhance the uptake of the NOS substrate L-arginine into endothelial cells. The ascorbic acid effect was minimal when the citrulline formation was measured in cell lysates from ascorbate-pretreated cells in the presence of known cofactors for NOS activity. However, when the cofactor tetrahydrobiopterin was omitted from the assay, a similar potentiating effect of ascorbate pretreatment as seen in intact cells was demonstrated, suggesting that ascorbic acid may either enhance the availability of tetrahydrobiopterin or increase its affinity for the endothelial NOS. Our data suggest that intracellular ascorbic acid enhances NO synthesis in endothelial cells and that this may explain, in part, the beneficial vascular effects of ascorbic acid.  (+info)

Biopterin derivatives in normal and phenylketonuric patients after oral loads of L-phenylalanine, L-tyrosine, and L-tryptophan. (2/830)

Plasma biopterin derivatives studied in 10 normal and 21 phenylketonuric children showed a significantly high concentration in the latter group. Biopterin derivatives correlated with plasma phenylalanine concentration, but in normal adults given an oral phenylalanine load the rate of increase with phenylalanine differed from that in phenylketonuric patients. A patient with hyperphenylalaninaemia, not due to phenylketonuria, had an abnormal biopterin derivatives response to phenylalanine distinct from that of patients with classical phenylketonuria. This may be a useful investigation to differentiate some variants of phenylketonuria.  (+info)

Protective effects of 5,6,7,8-tetrahydroneopterin against X-ray radiation injury in mice. (3/830)

The protective effects of 5,6,7,8-tetrahydroneopterin (NH4) against radiation injury in mice were studied. (C57BL/6xA/J)F1 (B6A) mice received a single whole-body irradiation dose of 200, 400, 700 or 800 cGy of X-rays. NH4 (30 mg/kg body weight) or phosphate-buffered saline (PBS) was injected intraperitoneally into irradiated mice 10 min before and after the irradiation and again after 6 h. All mice which received the 800 cGy radiation+PBS died between 8 and 11 days after the treatment. In contrast, those which also received NH4 demonstrated a significantly prolonged survival time and 40% lived more than 5 months. Total numbers of thymocytes and spleen cells on day 5 post-irradiation were dramatically reduced in line with the radiation dose. The survival was significantly enhanced by NH4 in treated mice. The proliferation of spleen cells in mice stimulated by concanavalin A (Con A) or lipopolysaccharide (LPS) was also greater in NH4 treated mice. The immune response of survivors 5 months after 800 cGy+NH4 treatments, against Con A, LPS, allogenic mouse, and sheep red blood cells had essentially recovered to the levels of normal mice. These results indicate that NH4 had an important role in modifying radiation injury.  (+info)

Hypoxia inhibits increased ETB receptor-mediated NO synthesis in hypertensive rat lungs. (4/830)

Although hypertensive lungs of chronically hypoxic rats express increased levels of nitric oxide (NO) synthases (NOSs) and produce increased amounts of NO-containing compounds (NOx) during normoxic ventilation, the level of NO production during hypoxic exposure is unclear. Because hypoxia inhibits NO synthesis in normotensive lungs, we investigated whether hypoxic ventilation inhibited NO synthesis in isolated hypertensive lungs and chronically hypoxic rats. Measurement of perfusate NOx concentration in hypertensive lungs from male rats exposed to 4 wk of hypobaric hypoxia showed that basal NOx production was reduced during hypoxic (0% O2) vs. normoxic (21% O2) ventilation. Similarly, plasma NOx concentration was lower in chronically hypoxic rats breathing 10% O2 than in those breathing 21% O2. Hypoxic inhibition of lung NOx production was not prevented by supplementary L-arginine or tetrahydrobiopterin and was not mimicked by inhibition of Ca2+ influx. However, it was mimicked by inhibition of constitutive NOS with NG-monomethyl-L-arginine and chelation of intracellular Ca2+. The endothelin type B-receptor antagonist BQ-788 prevented the increases in NOx production associated with normoxic ventilation in both isolated hypertensive lungs and intact chronically hypoxic rats. These results suggest that a reduced supply of the cosubstrate molecular O2 to NOS counteracts an endothelin type B receptor-mediated stimulation of NO synthesis in hypertensive rat lungs. Thus, despite increased NOS protein in the lungs and pulmonary arteries of chronically hypoxic rats, direct hypoxic inhibition of NO production may contribute to the development of pulmonary hypertension.  (+info)

Enzymatic synthesis of biopterin from D-erythrodihydroneopterin triphosphate by extracts of kidneys from Syrian golden hamsters. (5/830)

An enzyme system was found in either crude homogenates of dialyzed extracts of liver, kidney, lung, and brain from Syrian golden hamsters that catalyzed the synthesis of radioactive 6(L-erythro-1',2'-dihydroxypropyl)pterin (biopterin) from [U-14C]6(D-erythro-1',2',3'-trihydroxypropyl)-7,8-dihydropterin triphosphate (D-erythrolH2neopterin-PPP) preparation. The specific radioactivity of biopterin was found to be comparable to that of D-erythroH2neopterin-PPP. The enzyme system from hamster kidney was purified severalfold by fractionation with ammonium sulfate and with an Ultrogel AcA-34 column. It was demonstrated that (a) NADPH or NADAH was essential and that (b) Mg2+ was stimulatory for the enzymatic synthesis of biopterin from D-erythroH2-NEOPTERIN-PPP. Also GTP and nonphosphorylated neopterins were not converted to biopterin. Although 6-lactyl-7,8-dihydropterin (sepiapterin) was converted to biopterin in the presence of NADPH, sepiapterin was not detected from D-erythroH2neopterin-PPP in the absence of NADPH. A preliminary experiment was performed to identify dihydrobiopterin.  (+info)

Sepiapterin reductase producing L-threo-dihydrobiopterin from Chlorobium tepidum. (6/830)

A novel type of NADPH-dependent sepiapterin reductase, which catalysed uniquely the reduction of sepiapterin to l-threo-dihydrobiopterin, was purified 533-fold from the cytosolic fraction of Chlorobium tepidum, with an overall yield of 3%. The native enzyme had a molecular mass of 55 kDa and SDS/PAGE revealed that the enzyme consists of two subunits with a molecular mass of 26 kDa. The enzyme was optimally active at pH8.8 and 50 degrees C. Apparent Km values for sepiapterin and NADPH were 21 and 6.2 microM, respectively, and the kcat value was 5.0 s-1. Diacetyl could also serve as a substrate, with a Km of 4.0 mM. The inhibitory effects of N-acetylserotonin, N-acetyldopamine and melatonin were very weak. The Ki value of N-acetyldopamine was measured as 400 microM. The N-terminal amino acid sequence was revealed as Met-Lys-His-Ile-Leu-Leu-Ile-Thr-Gly-Ala-Xaa-Lys - Lys - Ile - Xaa - Arg - Ala - Ile - Ala - Leu - Glu - Xaa - Ala - Arg - Xaa-Xaa-Xaa-His-His-His-, which shared relatively high sequence similarity with other sepiapterin reductases.  (+info)

Activation of neuronal nitric-oxide synthase by the 5-methyl analog of tetrahydrobiopterin. Functional evidence against reductive oxygen activation by the pterin cofactor. (7/830)

Tetrahydrobiopterin ((6R)-5,6,7,8-tetrahydro-L-biopterin (H4biopterin)) is an essential cofactor of nitric-oxide synthases (NOSs), but its role in enzyme function is not known. Binding of the pterin affects the electronic structure of the prosthetic heme group in the oxygenase domain and results in a pronounced stabilization of the active homodimeric structure of the protein. However, these allosteric effects are also produced by the potent pterin antagonist of NOS, 4-amino-H4biopterin, suggesting that the natural cofactor has an additional, as yet unknown catalytic function. Here we show that the 5-methyl analog of H4biopterin, which does not react with O2, is a functionally active pterin cofactor of neuronal NOS. Activation of the H4biopterin-free enzyme occurred in a biphasic manner with half-maximally effective concentrations of approximately 0.2 microM and 10 mM 5-methyl-H4biopterin. Thus, the affinity of the 5-methyl compound was 3 orders of magnitude lower than that of the natural cofactor, allowing the direct demonstration of the functional anticooperativity of the two pterin binding sites of dimeric NOS. In contrast to H4biopterin, which inactivates nitric oxide (NO) through nonenzymatic superoxide formation, up to 1 mM of the 5-methyl derivative did not consume O2 and had no effect on NO steady-state concentrations measured electrochemically with a Clark-type NO electrode. Therefore, reconstitution with 5-methyl-H4biopterin allowed, for the first time, the detection of enzymatic NO formation in the absence of superoxide or NO scavengers. These results unequivocally identify free NO as a NOS product and indicate that reductive O2 activation by the pterin cofactor is not essential to NO biosynthesis.  (+info)

Functionally important residues tyrosine-171 and serine-158 in sepiapterin reductase. (8/830)

The active site of sepiapterin reductase (SPR), which is a member of the NADP(H)-preferring short-chain dehydrogenase/reductase (SDR) family and acts as the terminal enzyme in the biosynthetic pathway of tetrahydrobiopterin cofactor (BH4), was investigated by truncation and site-directed mutagenesis. The truncation mutants showed that N-terminal and C-terminal residues contribute to bind coenzyme and substrate, respectively. The mutant rSPRA29V showed decreased activity; however, the A-X-L-L-S sequence, which has been reported as a putative pterin binding site, was estimated to preferably work as a component in the region for binding coenzyme rather than substrate. Site-directed mutants of rSPRS158D, rSPRY171V, and rSPRK175I showed low, but significant, activity having similar Km values and kcat/Km values less than 25%, for both sepiapterin and NADPH. Both amino acids Tyr-171 and Ser-158 are located within a similar distance to the carbonyl group of the substrate in the crystal structure of mouse SPR, and the double point mutant rSPRY171V+S158D was indicated to be inactive. These results showed that Ser-158, Tyr-171, and Lys-175 contributed to the catalytic activity of SPR, and both Tyr-171 and Ser-158 are simultaneously necessary on proton transfer to the carbonyl functional groups of substrate.  (+info)

Biopterin is a type of pteridine compound that acts as a cofactor in various biological reactions, particularly in the metabolism of amino acids such as phenylalanine and tyrosine. It plays a crucial role in the production of neurotransmitters like dopamine, serotonin, and noradrenaline. Biopterin exists in two major forms: tetrahydrobiopterin (BH4) and dihydrobiopterin (BH2). BH4 is the active form that participates in enzymatic reactions, while BH2 is an oxidized form that can be reduced back to BH4 by the action of dihydrobiopterin reductase.

Deficiencies in biopterin metabolism have been linked to several neurological disorders, including phenylketonuria (PKU), dopamine-responsive dystonia, and certain forms of autism. In these conditions, the impaired synthesis or recycling of biopterin can lead to reduced levels of neurotransmitters, causing various neurological symptoms.

Pteridines are a class of heterocyclic aromatic organic compounds that are structurally related to pterins, which contain a pyrimidine ring fused to a pyrazine ring. They are naturally occurring substances that can be found in various living organisms such as bacteria, fungi, plants, and animals.

Pteridines have several important biological functions. For instance, they play a crucial role in the synthesis of folate and biotin, which are essential cofactors for various metabolic reactions in the body. Additionally, some pteridines function as chromophores, contributing to the coloration of certain organisms such as butterflies and birds.

In medicine, pteridines have been studied for their potential therapeutic applications. For example, some synthetic pteridine derivatives have shown promising results in preclinical studies as antitumor, antiviral, and antibacterial agents. However, further research is needed to fully understand the medical implications of these compounds.

Pterins are a group of naturally occurring pigments that are derived from purines. They are widely distributed in various organisms, including bacteria, fungi, and animals. In humans, pterins are primarily found in the eye, skin, and hair. Some pterins have been found to play important roles as cofactors in enzymatic reactions and as electron carriers in metabolic pathways.

Abnormal levels of certain pterins can be indicative of genetic disorders or other medical conditions. For example, an excess of biopterin, a type of pterin, is associated with phenylketonuria (PKU), a genetic disorder that affects the body's ability to metabolize the amino acid phenylalanine. Similarly, low levels of neopterin, another type of pterin, can be indicative of immune system dysfunction or certain types of cancer.

Medical professionals may measure pterin levels in blood, urine, or other bodily fluids to help diagnose and monitor these conditions.

Neopterin is a pteridine metabolite that is primarily produced by macrophages in response to the activation of the immune system, particularly in response to interferon-gamma (IFN-γ). It is commonly used as a biomarker for cellular immune activation and inflammation. Elevated levels of neopterin have been associated with various conditions such as infections, autoimmune diseases, cancer, and transplant rejection.

GTP Cyclohydrolase is a crucial enzyme in the biosynthetic pathway of neurotransmitters and other biogenic amines. It catalyzes the conversion of GTP (guanosine triphosphate) to dihydroneopterin triphosphate, which is a key intermediate in the production of tetrahydrobiopterin (BH4). Tetrahydrobiopterin serves as a cofactor for various enzymes involved in the synthesis of neurotransmitters such as dopamine, serotonin, and noradrenaline.

There are two main isoforms of GTP Cyclohydrolase: GTPCH1 (GTP Cyclohydrolase 1) and GTPCH2 (GTP Cyclohydrolase 2). GTPCH1 is primarily expressed in the brain, kidneys, and lungs, while GTPCH2 is mainly found in the liver. Defects or mutations in the GTPCH1 gene can lead to a rare genetic disorder known as Dopa-Responsive Dystonia (DRD), which is characterized by symptoms such as muscle stiffness, involuntary movements, and Parkinsonism.

Dihydropteridine reductase is an enzyme that plays a crucial role in the metabolism of certain amino acids, specifically phenylalanine and tyrosine. This enzyme is responsible for reducing dihydropteridines to tetrahydropteridines, which is a necessary step in the regeneration of tetrahydrobiopterin (BH4), an essential cofactor for the enzymes phenylalanine hydroxylase and tyrosine hydroxylase.

Phenylalanine hydroxylase and tyrosine hydroxylase are involved in the conversion of the amino acids phenylalanine and tyrosine to tyrosine and dopa, respectively. Without sufficient BH4, these enzymes cannot function properly, leading to an accumulation of phenylalanine and a decrease in the levels of important neurotransmitters such as dopamine, norepinephrine, and serotonin.

Deficiency in dihydropteridine reductase can lead to a rare genetic disorder known as dihydropteridine reductase deficiency (DPRD), which is characterized by elevated levels of phenylalanine and neurotransmitter imbalances, resulting in neurological symptoms such as developmental delay, seizures, and hypotonia. Treatment typically involves a low-phenylalanine diet and supplementation with BH4.

Phosphorus-Oxygen Lyases are a class of enzymes that catalyze the breakdown of a substrate containing a phosphorus-oxygen bond, releasing a phosphate group and forming a new double bond in the process. This reaction is typically represented by the general formula:

Substrate-P-O + A acceptor ------> Substrate-O=A + P\_i

where "Substrate-P-O" represents the phosphorus-oxygen bond in the substrate, "A acceptor" is the molecule that accepts the phosphate group, and "P\_i" denotes inorganic phosphate. These enzymes play important roles in various biological processes, such as signal transduction, energy metabolism, and biosynthesis.

Examples of Phosphorus-Oxygen Lyases include:

1. Phospholipase D - catalyzes the hydrolysis of phosphatidylcholine to produce phosphatidic acid and choline.
2. ATP sulfurylase - catalyzes the formation of adenosine 5'-phosphosulfate (APS) from ATP and sulfate, which is an important intermediate in the biosynthesis of sulfur-containing amino acids.
3. Inositol polyphosphate 1-phosphatase - catalyzes the dephosphorylation of inositol polyphosphates, which are involved in intracellular signaling pathways.
4. UDP-glucose pyrophosphorylase - catalyzes the reversible conversion of UDP-glucose and pyrophosphate to glucose-1-phosphate and UTP, playing a crucial role in carbohydrate metabolism.

It is important to note that Phosphorus-Oxygen Lyases are distinct from Phosphoric Monoester Hydrolases, which also catalyze the hydrolysis of phosphorus-oxygen bonds but do not form new double bonds in the process.

Phenylketonurias (PKU) is a genetic disorder characterized by the body's inability to properly metabolize the amino acid phenylalanine, due to a deficiency of the enzyme phenylalanine hydroxylase. This results in a buildup of phenylalanine in the blood and other tissues, which can cause serious neurological problems if left untreated.

The condition is typically detected through newborn screening and can be managed through a strict diet that limits the intake of phenylalanine. If left untreated, PKU can lead to intellectual disability, seizures, behavioral problems, and other serious health issues. In some cases, medication or a liver transplant may also be necessary to manage the condition.

'Dystonia Musculorum Deformans' is a medical term that refers to a rare inherited neurological disorder, which is now more commonly known as "Generalized Dystonia." This condition is characterized by sustained muscle contractions, leading to twisting and repetitive movements or abnormal postures.

The onset of symptoms typically occurs during childhood or adolescence, and they can progress over time, affecting various parts of the body. The exact cause of Generalized Dystonia is not fully understood, but it is believed to involve genetic mutations that affect the functioning of certain proteins in the brain. Treatment options may include medications, botulinum toxin injections, or even deep brain stimulation surgery in severe cases.

Aminopterin is a type of anti-folate drug that is primarily used in cancer treatment and research. It works by inhibiting the enzyme dihydrofolate reductase, which is necessary for the synthesis of nucleotides, the building blocks of DNA and RNA. By blocking this enzyme, aminopterin prevents the growth and multiplication of cancer cells.

In addition to its use in cancer treatment, aminopterin has also been used in experimental studies to investigate the role of folate metabolism in various biological processes, including embryonic development and immune function. However, due to its potent anti-proliferative effects, the use of aminopterin is limited to specialized medical and research settings, and it is not commonly used as a therapeutic agent in clinical practice.

Phenylalanine Hydroxylase (PAH) is an enzyme that plays a crucial role in the metabolism of the essential amino acid phenylalanine. This enzyme is primarily found in the liver and is responsible for converting phenylalanine into tyrosine, another amino acid. PAH requires a cofactor called tetrahydrobiopterin (BH4) to function properly.

Defects or mutations in the gene that encodes PAH can lead to a genetic disorder known as Phenylketonuria (PKU). In PKU, the activity of PAH is significantly reduced or absent, causing an accumulation of phenylalanine in the body. If left untreated, this condition can result in severe neurological damage and intellectual disability due to the toxic effects of high phenylalanine levels on the developing brain. A strict low-phenylalanine diet and regular monitoring of blood phenylalanine levels are essential for managing PKU and preventing associated complications.

Phenylalanine is an essential amino acid, meaning it cannot be produced by the human body and must be obtained through diet or supplementation. It's one of the building blocks of proteins and is necessary for the production of various molecules in the body, such as neurotransmitters (chemical messengers in the brain).

Phenylalanine has two forms: L-phenylalanine and D-phenylalanine. L-phenylalanine is the form found in proteins and is used by the body for protein synthesis, while D-phenylalanine has limited use in humans and is not involved in protein synthesis.

Individuals with a rare genetic disorder called phenylketonuria (PKU) must follow a low-phenylalanine diet or take special medical foods because they are unable to metabolize phenylalanine properly, leading to its buildup in the body and potential neurological damage.

"Escherichia coli (E. coli) meningitis" is a specific type of bacterial meningitis, which is an inflammation of the membranes covering the brain and spinal cord (meninges). E. coli is a gram-negative, facultatively anaerobic, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms. While most strains of E. coli are harmless and even beneficial to their hosts, some serotypes can cause severe food poisoning and other illnesses.

E. coli meningitis is relatively rare but can occur in newborns and young infants, particularly those who are premature or have underlying health conditions that weaken their immune systems. The bacteria can enter the bloodstream and travel to the brain, causing meningitis. Symptoms of E. coli meningitis may include fever, vomiting, irritability, lethargy, seizures, and a stiff neck.

E. coli meningitis is a serious medical emergency that requires prompt treatment with antibiotics to prevent complications such as brain damage or hearing loss. Infants who are diagnosed with E. coli meningitis may also require supportive care, such as fluid replacement and respiratory support, to help them recover.

5-Hydroxytryptophan (5-HTP) is a chemical compound that is produced by the body as a precursor to serotonin, a neurotransmitter that helps regulate mood, appetite, sleep, and pain sensation. 5-HTP is not present in food but can be derived from the amino acid tryptophan, which is found in high-protein foods such as turkey, chicken, milk, and cheese.

5-HTP supplements are sometimes used to treat conditions related to low serotonin levels, including depression, anxiety, insomnia, migraines, and fibromyalgia. However, the effectiveness of 5-HTP for these conditions is not well established, and it can have side effects and interact with certain medications. Therefore, it's important to consult a healthcare provider before taking 5-HTP supplements.

Hypoxanthine is not a medical condition but a purine base that is a component of many organic compounds, including nucleotides and nucleic acids, which are the building blocks of DNA and RNA. In the body, hypoxanthine is produced as a byproduct of normal cellular metabolism and is converted to xanthine and then uric acid, which is excreted in the urine.

However, abnormally high levels of hypoxanthine in the body can indicate tissue damage or disease. For example, during intense exercise or hypoxia (low oxygen levels), cells may break down ATP (adenosine triphosphate) rapidly, releasing large amounts of hypoxanthine. Similarly, in some genetic disorders such as Lesch-Nyhan syndrome, there is an accumulation of hypoxanthine due to a deficiency of the enzyme that converts it to xanthine. High levels of hypoxanthine can lead to the formation of kidney stones and other complications.

Nitric Oxide Synthase (NOS) is a group of enzymes that catalyze the production of nitric oxide (NO) from L-arginine. There are three distinct isoforms of NOS, each with different expression patterns and functions:

1. Neuronal Nitric Oxide Synthase (nNOS or NOS1): This isoform is primarily expressed in the nervous system and plays a role in neurotransmission, synaptic plasticity, and learning and memory processes.
2. Inducible Nitric Oxide Synthase (iNOS or NOS2): This isoform is induced by various stimuli such as cytokines, lipopolysaccharides, and hypoxia in a variety of cells including immune cells, endothelial cells, and smooth muscle cells. iNOS produces large amounts of NO, which functions as a potent effector molecule in the immune response, particularly in the defense against microbial pathogens.
3. Endothelial Nitric Oxide Synthase (eNOS or NOS3): This isoform is constitutively expressed in endothelial cells and produces low levels of NO that play a crucial role in maintaining vascular homeostasis by regulating vasodilation, inhibiting platelet aggregation, and preventing smooth muscle cell proliferation.

Overall, NOS plays an essential role in various physiological processes, including neurotransmission, immune response, cardiovascular function, and respiratory regulation. Dysregulation of NOS activity has been implicated in several pathological conditions such as hypertension, atherosclerosis, neurodegenerative diseases, and inflammatory disorders.

Alcohol oxidoreductases are a class of enzymes that catalyze the oxidation of alcohols to aldehydes or ketones, while reducing nicotinamide adenine dinucleotide (NAD+) to NADH. These enzymes play an important role in the metabolism of alcohols and other organic compounds in living organisms.

The most well-known example of an alcohol oxidoreductase is alcohol dehydrogenase (ADH), which is responsible for the oxidation of ethanol to acetaldehyde in the liver during the metabolism of alcoholic beverages. Other examples include aldehyde dehydrogenases (ALDH) and sorbitol dehydrogenase (SDH).

These enzymes are important targets for the development of drugs used to treat alcohol use disorder, as inhibiting their activity can help to reduce the rate of ethanol metabolism and the severity of its effects on the body.

A biological assay is a method used in biology and biochemistry to measure the concentration or potency of a substance (like a drug, hormone, or enzyme) by observing its effect on living cells or tissues. This type of assay can be performed using various techniques such as:

1. Cell-based assays: These involve measuring changes in cell behavior, growth, or viability after exposure to the substance being tested. Examples include proliferation assays, apoptosis assays, and cytotoxicity assays.
2. Protein-based assays: These focus on measuring the interaction between the substance and specific proteins, such as enzymes or receptors. Examples include enzyme-linked immunosorbent assays (ELISAs), radioimmunoassays (RIAs), and pull-down assays.
3. Genetic-based assays: These involve analyzing the effects of the substance on gene expression, DNA structure, or protein synthesis. Examples include quantitative polymerase chain reaction (qPCR) assays, reporter gene assays, and northern blotting.

Biological assays are essential tools in research, drug development, and diagnostic applications to understand biological processes and evaluate the potential therapeutic efficacy or toxicity of various substances.

Methotrexate is a medication used in the treatment of certain types of cancer and autoimmune diseases. It is an antimetabolite that inhibits the enzyme dihydrofolate reductase, which is necessary for the synthesis of purines and pyrimidines, essential components of DNA and RNA. By blocking this enzyme, methotrexate interferes with cell division and growth, making it effective in treating rapidly dividing cells such as cancer cells.

In addition to its use in cancer treatment, methotrexate is also used to manage autoimmune diseases such as rheumatoid arthritis, psoriasis, and inflammatory bowel disease. In these conditions, methotrexate modulates the immune system and reduces inflammation.

It's important to note that methotrexate can have significant side effects and should be used under the close supervision of a healthcare provider. Regular monitoring of blood counts, liver function, and kidney function is necessary during treatment with methotrexate.

Nitric Oxide Synthase Type I, also known as NOS1 or neuronal nitric oxide synthase (nNOS), is an enzyme that catalyzes the production of nitric oxide (NO) from L-arginine. It is primarily expressed in the nervous system, particularly in neurons, and plays a crucial role in the regulation of neurotransmission, synaptic plasticity, and cerebral blood flow. NOS1 is calcium-dependent and requires several cofactors for its activity, including NADPH, FAD, FMN, and calmodulin. It is involved in various physiological and pathological processes, such as learning and memory, seizure susceptibility, and neurodegenerative disorders.

Nitric Oxide Synthase Type III (NOS-III), also known as endothelial Nitric Oxide Synthase (eNOS), is an enzyme responsible for the production of nitric oxide (NO) in the endothelium, the lining of blood vessels. This enzyme catalyzes the conversion of L-arginine to L-citrulline, producing NO as a byproduct. The release of NO from eNOS plays an important role in regulating vascular tone and homeostasis, including the relaxation of smooth muscle cells in the blood vessel walls, inhibition of platelet aggregation, and modulation of immune function. Mutations or dysfunction in NOS-III can contribute to various cardiovascular diseases such as hypertension, atherosclerosis, and erectile dysfunction.

Nitric oxide (NO) is a molecule made up of one nitrogen atom and one oxygen atom. In the body, it is a crucial signaling molecule involved in various physiological processes such as vasodilation, immune response, neurotransmission, and inhibition of platelet aggregation. It is produced naturally by the enzyme nitric oxide synthase (NOS) from the amino acid L-arginine. Inhaled nitric oxide is used medically to treat pulmonary hypertension in newborns and adults, as it helps to relax and widen blood vessels, improving oxygenation and blood flow.

High-performance liquid chromatography (HPLC) is a type of chromatography that separates and analyzes compounds based on their interactions with a stationary phase and a mobile phase under high pressure. The mobile phase, which can be a gas or liquid, carries the sample mixture through a column containing the stationary phase.

In HPLC, the mobile phase is a liquid, and it is pumped through the column at high pressures (up to several hundred atmospheres) to achieve faster separation times and better resolution than other types of liquid chromatography. The stationary phase can be a solid or a liquid supported on a solid, and it interacts differently with each component in the sample mixture, causing them to separate as they travel through the column.

HPLC is widely used in analytical chemistry, pharmaceuticals, biotechnology, and other fields to separate, identify, and quantify compounds present in complex mixtures. It can be used to analyze a wide range of substances, including drugs, hormones, vitamins, pigments, flavors, and pollutants. HPLC is also used in the preparation of pure samples for further study or use.

Tetrahydrofolate dehydrogenase (EC 1.5.1.20) is an enzyme involved in folate metabolism. The enzyme catalyzes the oxidation of tetrahydrofolate (THF) to dihydrofolate (DHF), while simultaneously reducing NADP+ to NADPH.

The reaction can be summarized as follows:

THF + NADP+ -> DHF + NADPH + H+

This enzyme plays a crucial role in the synthesis of purines and thymidylate, which are essential components of DNA and RNA. Therefore, any defects or deficiencies in tetrahydrofolate dehydrogenase can lead to various medical conditions, including megaloblastic anemia and neural tube defects during fetal development.

Superoxides are partially reduced derivatives of oxygen that contain one extra electron, giving them an overall charge of -1. They are highly reactive and unstable, with the most common superoxide being the hydroxyl radical (•OH-) and the superoxide anion (O2-). Superoxides are produced naturally in the body during metabolic processes, particularly within the mitochondria during cellular respiration. They play a role in various physiological processes, but when produced in excess or not properly neutralized, they can contribute to oxidative stress and damage to cells and tissues, potentially leading to the development of various diseases such as cancer, atherosclerosis, and neurodegenerative disorders.

Oxidation-Reduction (redox) reactions are a type of chemical reaction involving a transfer of electrons between two species. The substance that loses electrons in the reaction is oxidized, and the substance that gains electrons is reduced. Oxidation and reduction always occur together in a redox reaction, hence the term "oxidation-reduction."

In biological systems, redox reactions play a crucial role in many cellular processes, including energy production, metabolism, and signaling. The transfer of electrons in these reactions is often facilitated by specialized molecules called electron carriers, such as nicotinamide adenine dinucleotide (NAD+/NADH) and flavin adenine dinucleotide (FAD/FADH2).

The oxidation state of an element in a compound is a measure of the number of electrons that have been gained or lost relative to its neutral state. In redox reactions, the oxidation state of one or more elements changes as they gain or lose electrons. The substance that is oxidized has a higher oxidation state, while the substance that is reduced has a lower oxidation state.

Overall, oxidation-reduction reactions are fundamental to the functioning of living organisms and are involved in many important biological processes.

... compounds found in the animal body include BH4, the free radical BH3•, and the semi-oxidized form BH2. The fully ... Biopterin synthesis disorders are also a cause of hyperphenylalaninemia; phenylalanine metabolism requires BH4 as a cofactor. ... A number of disorders of biopterin regulation exist. Single-gene defects affecting the gene GCH1 block the first step in ... Mouse gene knockout models that block biopterin synthesis completely die shortly after birth due to their inability to produce ...
The folate-biopterin transporter (FBT) family (TC# 2.A.71) is a distant family within the major facilitator superfamily, most ... As of this edit, this article uses content from "2.A.71 The Folate-Biopterin Transporter (FBT) Family", which is licensed in a ... A related protein in Trypanosoma brucei, ESAGIO, shows weak folate/biopterin transport activity. There are at least 6 ... The probable transport reaction catalyzed by characterized FBT family members is: [folate, biopterin, or AdoMet] (out) + H+ ( ...
... s (AAAH) are a family of aromatic amino acid hydroxylase enzymes which ...
GTPCH is part of the folate and biopterin biosynthesis pathways. It is responsible for the hydrolysis of guanosine triphosphate ... Longo N (June 2009). "Disorders of biopterin metabolism". Journal of Inherited Metabolic Disease. 32 (3): 333-42. doi:10.1007/ ...
Sepiapterin reductase Longo N (June 2009). "Disorders of biopterin metabolism". Journal of Inherited Metabolic Disease. 32 (3 ...
"Cerebrospinal fluid biogenic amines and biopterin in Rett syndrome". Annals of Neurology. 25 (1): 56-60. doi:10.1002/ana. ...
The major blue fluorescent pigment contributing to the fluorescence of M. sulkowskyi was found to be L-erythro biopterin, along ... Tabata, H.; Hasegawa, T.; Nakagoshi, M.; Takikawa, S.; Tsusue, M. "Occurrence of biopterin in the wings of Morpho butterflies ...
... biopterin and neopterin concentrations". Molecular Genetics and Metabolism. 95 (3): 127-32. doi:10.1016/j.ymgme.2008.07.004. ...
Blood concentrations of neopterin and biopterin in subjects with depression: A systematic review and meta-analysis Progress in ... Blood concentrations of neopterin and biopterin in subjects with depression: A systematic review and meta-analysis Progress in ... Blood concentrations of neopterin and biopterin in subjects with depression: A systematic review and meta-analysis Progress in ... Blood concentrations of neopterin and biopterin in subjects with depression: A systematic review and meta-analysis Progress in ...
Tyrosine hydroxylase, phenylalanine hydroxylase, and tryptophan hydroxylase together constitute the family of biopterin- ...
Sawada M, Hirata Y, Arai H, Iizuka R, Nagatsu T (Mar 1987). "Tyrosine hydroxylase, tryptophan hydroxylase, biopterin, and ...
... and usually have decreased levels of biopterin and neopterin in urine and in dry blood spots. According to a consensus ...
Blood concentrations of neopterin and biopterin in subjects with depression: A systematic review and meta-analysis Progress in ... Blood concentrations of neopterin and biopterin in subjects with depression: A systematic review and meta-analysis Progress in ... Blood concentrations of neopterin and biopterin in subjects with depression: A systematic review and meta-analysis Progress in ... Blood concentrations of neopterin and biopterin in subjects with depression: A systematic review and meta-analysis Progress in ...
PCDD is associated with elevatel levels of primapterin, especially in urine, while biopterin levels range from low to normal, ...
... relative importance of the de novo biopterin synthesis versus salvage pathways". The Journal of Biological Chemistry. 284 (41 ...
June 1998). "Hyperphenylalaninemia with high levels of 7-biopterin is associated with mutations in the PCBD gene encoding the ...
Tryptophan hydroxylases catalyze the biopterin-dependent monooxygenation of tryptophan to 5-hydroxytryptophan (5-HTP), which is ...
The molecular formula C9H11N5O3 (molar mass: 237.21 g/mol, exact mass: 237.0862 u) may refer to: Biopterin Dyspropterin ...
... biopterin MeSH D03.438.733.631.202.500 - neopterin MeSH D03.438.733.631.400 - folic acid MeSH D03.438.733.631.400.600 - ...
Folate-biopterin transporter family Frost Bank Tower, Austin, Texas, US Greg Mueller (born 1971), Canadian poker player, ...
BH4 is a cofactor for the biopterin-dependent aromatic amino acid hydroxylase enzymes, which catalyze the conversion of ...
... biopterin + 2 NADPH + 2 H+ Thus, the two substrates of this enzyme are 5,6,7,8-tetrahydrobiopterin and NADP+, whereas its 3 ... products are biopterin, NADPH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the ...
Family 2.A.71 The Folate-Biopterin Transporter (FBT) Family 2.A.72 The K+ Uptake Permease (KUP) Family 2.A.73 The Short Chain ...
PAH is one of three members of the biopterin-dependent aromatic amino acid hydroxylases, a class of monooxygenase that uses ...
... but neopterin and biopterin were abnormal in only one sibling. The results of this research indicates that when diagnosing the ... quantification of sepiapterin in the CSF is more important and indicative of SR deficiency than using neopterin and biopterin ...
Sometimes a lumbar puncture is performed to measure concentrations of biopterin and neopterin, which can help determine the ... exact form of dopamine-responsive movement disorder: early onset parkinsonism (reduced biopterin and normal neopterin), GTP ...
Tyrosinemia II Argininemia Benign hyperphenylalaninemia Defects of biopterin cofactor biosynthesis Defects of biopterin ...
Biopterin compounds found in the animal body include BH4, the free radical BH3•, and the semi-oxidized form BH2. The fully ... Biopterin synthesis disorders are also a cause of hyperphenylalaninemia; phenylalanine metabolism requires BH4 as a cofactor. ... A number of disorders of biopterin regulation exist. Single-gene defects affecting the gene GCH1 block the first step in ... Mouse gene knockout models that block biopterin synthesis completely die shortly after birth due to their inability to produce ...
Biopterin synthesis defect. Treatment with L-dopa and 5-hydroxytryptophan compared with therapy with a tetrahydropterin.. ... Biopterin synthesis defect. Treatment with L-dopa and 5-hydroxytryptophan compared with therapy with a tetrahydropterin.. ... We have identified a generalized deficiency of monoamine neurotransmitters in a patient with a defect in biopterin synthesis. ... but suggest that this treatment may be partially effective in biopterin-deficient patients who are unresponsive to high doses ...
... When cursor points to a box further details will be displayed in a tooltip window. If you click on the ...
Animals, Biopterin, Cardiovascular Diseases, Endothelial Cells, Folic Acid, Humans, Mice, Nitric Oxide, Tetrahydrofolate ...
Biopterin defect in cofactor biosynthesis Biopterin defect in cofactor regeneration Tyrosinemia, type II ...
Longo N. Disorders of biopterin metabolism. J Inherit Metab Dis. 2009 Jun;32(3):333-42. doi: 10.1007/s10545-009-1067-2. Epub ...
The urinary pterins analysis showed low biopterin levels, low percentages of urinary biopterin, and high neopterin levels. [27 ... Longo N. Disorders of biopterin metabolism. J Inherit Metab Dis. 2009 Jun. 3:333-42. [QxMD MEDLINE Link]. ...
The outcome of patients with disorders of biopterin synthesis can be favorable, with either normal or near-normal cognition, ... 3 Longo N. Disorders of biopterin metabolism. J Inherit Metab Dis 2009; 32 (3) 333-342 ... biopterin, dopamine, and serotonin deficiencies and muscular hypotonia. Eur J Pediatr 1984; 141 (4) 208-214 ...
Biopterin defect in cofactor biosynthesis. Biopterin defect in cofactor regeneration. Biotinidase deficiency. Carnitine ...
BIOPT-BS) Defects of biopterin cofactor biosynthesis**. *(CIT-II) Citrullinemia, type II** ...
Background: The aim of this study is to investigate potentially curable or treatable medical conditions in unselected newborns using genomic sequencing(GS). Methods: 321 newborns from a cohort of pregnant women from Qingdao, China, underwent high-depth ...
Data enabled prediction analysis assigns folate/biopterin transporter (BT1) family to 36 hypothetical membrane proteins in ...
Biopterin studies are also suggested by most screening programs, along with supplemental tests that may help in further ...
Urine neopterin (N), biopterin (B) content, and biopterin B% (B/(B + N)) were determined by high-performance liquid ...
... normal tyrosine and normal biopterin) and 1 case as PKU due to biopterin defect. The incidence of PKU in the UAE was similar to ... normal tyrosine and normal biopterin) and 1 case as PKU due to biopterin defect. Of the borderline cases, 61 (80.1%) were false ...
Keywords: Neopterin, Biopterin, Pyrano[3,2-g]pteridine DOI: https://doi.org/10.5012/bkcs.2011.32.8.3161 ...
Besides participating in Methionine_Homocysteine cycle, folate has a main role in biopterin-dependent neurotransmitters ...
A)Metabolic precursors: L-Phen-yla-lanine, L-Tyro-sine, L-DOPA, Biopterin, Pyrido-xal--ph-osphate B)Reuptake inhibitors: Aminep ...
Anderson, J. M., Hamon, C. G. B., Armstrong, R. A. & Blair, J. A., 1986, Chemistry and Biology of Pteridines. Cooper, B. A. & Whitehead, V. M. (eds.). Berlin (DE): Walter De Gruyter, p. 327-330 4 p.. Research output: Chapter in Book/Published conference output › Chapter ...
Pterins may play an important part in the sex determination of some insects, for example, stepwise additions of biopterin have ...
... decreased biopterin levels by , 99% and inhibited nitric oxide synthesis by 90%. This inhibition could be reversed by loading ... biopterin levels decreased by 90% within 6 hr, whereas nitrite production was essentially unaffected. Pretreatment of the cells ...
One patient with hyperphenylalaninemia underwent urinary pterin assay and was suspected to be suffering from biopterin pathway ...
Human mononuclear phagocyte inducible nitric oxide synthase (iNOS): analysis of iNOS mRNA, iNOS protein, biopterin, and nitric ...
Description: Enzyme-linked immunosorbent assay kit for quantification of General Biopterin in samples from serum, plasma, ...
As noted earlier, the folate/biopterin family of transporters is increased (at 5), and thus, T. equi may import additional ... a large number of folate-biopterin transporters were predicted, suggesting that T. equi imports folate which is then modified ...
Disturbed biopterin and folate metabolism in the Qdpr-deficient mouse. FEBS Lett. 2014;588:3924-31. ... Cerebrospinal fluid biogenic amines and biopterin in Rett syndrome. Ann Neurol. 1989;25:56-60. ...
Biopterin, isoxanthopterin and 6-pterincarboxylic acid were identified in the head of the malaria vector mosquito Anopheles ... We have found normal concentrations of neopterin, monapterin, isoxanthopterin, biopterin and pterin in the urine of 10 patients ... with Rett syndrome, and normal values for total biopterin and neopterin in the blood of 4 subjects [2]. ...
Duch, D., Woolf, J., Nichol, C., Davidson, J., & Garbutt, J., (1984). Urinary excretion of biopterin and neopterin in ...
  • Blood concentrations of neopterin and biopterin in subjects with depression: A systematic review and meta-analysis Progress in Neuro-Psychopharmacology and Biological Psychiatry 2022. (wikipedia.org)
  • Urinary neopterin and biopterin were analyzed. (qxmd.com)
  • CSF examination is not performed routinely, but some subjects may show significant reductions in CSF levels of neopterin and biopterin. (medscape.com)
  • 6-Biopterin is a natural product,is a NO synthase cofactor. (targetmol.com)
  • Tryptophan uses biopterin as a cofactor to become serotonin which is why most of the body's serotonin production occur in the gut. (mthfrdoctors.com)
  • When the cells were stimulated in the presence of 2,4-diamino-6-hydroxypyrimidine (DAHP), an inhibitor of BH4 biosynthesis, biopterin levels decreased by 90% within 6 hr, whereas nitrite production was essentially unaffected. (aspetjournals.org)
  • Nitric oxide synthesis also uses biopterin derivatives as cofactors. (wikipedia.org)
  • Single-gene defects affecting the gene GCH1 block the first step in biopterin synthesis, and lead to dopamine-responsive dystonia, also known as Segawa's syndrome. (wikipedia.org)
  • Mouse gene knockout models that block biopterin synthesis completely die shortly after birth due to their inability to produce catecholamines and neurotransmitters. (wikipedia.org)
  • Biopterin synthesis defect. (jci.org)
  • We have identified a generalized deficiency of monoamine neurotransmitters in a patient with a defect in biopterin synthesis. (jci.org)
  • The outcome of patients with disorders of biopterin synthesis can be favorable, with either normal or near-normal cognition, and with some residual neurological symptoms usually manifesting diurnal variation, that is, worst when patients become tired or when the dosage or interval for medications is inadequate. (thieme-connect.de)
  • Urinary excretion of biopterin and neopterin in psychiatric disorders. (bvsalud.org)
  • The diagnosis is made by abnormal urinary pterin metabolites (low biopterin and high neopterin), reduced levels of cerebrospinal fluid (CSF) neurotransmitters homovanillic acid (HVA) and 5-hydroxy indoleacetic acid (5-HIAA) and the presence of a pathogenic mutation in the PTS gene. (rarediseasesjournal.com)
  • http://dx.doi.org/10.1016/j.pnpbp.2022.110633 Neurological aspects of biopterin metabolism WiseGeek. (wikipedia.org)
  • Longo N. Disorders of biopterin metabolism. (medlineplus.gov)
  • Apart from making neurotransmitters the biopterin produced from methylation also helps clear ammonia from the body. (mthfrdoctors.com)
  • A number of disorders of biopterin regulation exist. (wikipedia.org)
  • In psychiatry, imbalances of biopterin concentrations have been hypothesized to be linked to mood disorders, particularly depression. (wikipedia.org)
  • [ 16 ] may be useful in distinguishing the 3 disorders that are responsive to levodopa: GTPCH-deficient DRD (decreased biopterin and neopterin), TH-deficient DRD (normal biopterin and neopterin), and early-onset parkinsonism (reduced biopterin and normal neopterin). (medscape.com)
  • PKU is customarily caused by a deficiency of the phenylalanine hydroxylase apoenzyme (PAH), but other causes may include a deficiency of dihydropteridine reductase (DHPR) or reduced production of biopterin (BH 4 ). (nih.gov)
  • At the age of 4 months, she was noted to have hypotonia which led to the diagnosis of PTPS deficiency based on high plasma phenylalanine levels, its response to BH4 loading test, low biopterin with high neopterin levels in urine and subsequently confirmed by genetic analysis. (rarediseasesjournal.com)
  • Hyperphenylalaninemia due to a deficiency of biopterin. (cytgen.com)
  • Bacteria produce several unique glycosides of biopterin (and of other pterins as well), using a specific BPt glucosyltransferase. (wikipedia.org)
  • Data enabled prediction analysis assigns folate/biopterin transporter (BT1) family to 36 hypothetical membrane proteins in Leishmania donovani. (ncbs.res.in)
  • His Nitric oxide study which covers Mesenteric arteries that intersects with Dihydrobiopterin and Biopterin. (research.com)
  • The chemical reactions and pathways involving tetrahydrobiopterin, the reduced form of biopterin (2-amino-4-hydroxy-6-(1,2-dihydroxypropyl)-pteridine). (ntu.edu.sg)
  • The fully oxidized form, i.e. "biopterin" proper, has little biological significance. (wikipedia.org)
  • These findings indicate the complexity in replacement therapy with L-dopa and 5-HTP, but suggest that this treatment may be partially effective in biopterin-deficient patients who are unresponsive to high doses of tetrahydropterins. (jci.org)
  • For our protein two domains are included (ACT and Biopterin domain). (tu-muenchen.de)
  • Biopterin studies are also suggested by most screening programs, along with supplemental tests that may help in further diagnosis and nutritional management. (nih.gov)
  • Folate is the main substrate needed to get the methylation cycle going to produce biopterin and eventually SAMe . (mthfrdoctors.com)
  • Biopterin and dopamine contents, and TH activity in the striatum were poorly restored compared with those in the midbrain. (fujita-hu.ac.jp)
  • Blood concentrations of neopterin and biopterin in subjects with depression: A systematic review and meta-analysis Progress in Neuro-Psychopharmacology and Biological Psychiatry 2022. (wikipedia.org)
  • 9. Urinary excretion of biopterin and neopterin in psychiatric disorders. (nih.gov)
  • Urinary neopterin and biopterin were analyzed. (qxmd.com)
  • In this thesis, the relationship between blood lead levels and urinary neopterin, biopterin, manganese, cadmium and serum neopterin, kynurenine and tryptophan concentrations were evaluated in participants working in the recycling industry. (hacettepe.edu.tr)
  • He is also testing her urine for biopterin and neopterin, this is also in regards to DRD. (blogspot.com)
  • PKU is customarily caused by a deficiency of the phenylalanine hydroxylase apoenzyme (PAH), but other causes may include a deficiency of dihydropteridine reductase (DHPR) or reduced production of biopterin (BH 4 ). (nih.gov)
  • Dihydropteridine reductase deficiency presents as atypical phenylketonuria due to insufficient production of biopterin, a cofactor for phenylalanine hydroxylase. (nih.gov)
  • Low production of biopterin, leading to low neurotransmitters and depressed or altered mood. (geniusbiofeedback.com)
  • Adv Exp Med Biol 625:133В-140 Nare B, Garraway LA, Vickers TJ, Beverley SM (2009) PTR1-dependent unifying of tetrahydro- biopterin contributes to oxidant susceptibility in the trypanosomatid protozoan freeloader Leishmania major. (janmille.ru)
  • To inform the vascular surgeons that oxidative stress can disrupt the biopterin system impairing vascular function. (vascular.org)
  • Description: Enzyme-linked immunosorbent assay kit for quantification of General Biopterin in samples from serum, plasma, tissue homogenates and other biological fluids. (iowaodes.com)
  • C-phenylalanine breath test and serum biopterin in schizophrenia, bipolar disorder and major depressive disorder. (cdc.gov)
  • Dihydrofolate reductase and biopterin recycling in cardiovascular disease. (ox.ac.uk)
  • Single-gene defects affecting the gene GCH1 block the first step in biopterin synthesis, and lead to dopamine-responsive dystonia, also known as Segawa's syndrome. (wikipedia.org)
  • The prototypical compound of the class is biopterin (6-(1,2-dihydroxypropyl)-pterin), as shown in the infobox. (wikipedia.org)
  • Nitric oxide synthesis also uses biopterin derivatives as cofactors. (wikipedia.org)
  • Ronopterin inhibits NOS as an analogue of the natural co-factor, biopterin . (labiotech.eu)
  • A male supplement that contains Biopterin can create of these natural ingredients on the market to your body. (smallbusinessidea.in)