Hypoxanthine
A purine and a reaction intermediate in the metabolism of adenosine and in the formation of nucleic acids by the salvage pathway.
Hypoxanthines
Purine bases related to hypoxanthine, an intermediate product of uric acid synthesis and a breakdown product of adenine catabolism.
Hypoxanthine Phosphoribosyltransferase
An enzyme that catalyzes the conversion of 5-phosphoribosyl-1-pyrophosphate and hypoxanthine, guanine, or 6-mercaptopurine to the corresponding 5'-mononucleotides and pyrophosphate. The enzyme is important in purine biosynthesis as well as central nervous system functions. Complete lack of enzyme activity is associated with the LESCH-NYHAN SYNDROME, while partial deficiency results in overproduction of uric acid. EC 2.4.2.8.
Inosine
A purine nucleoside that has hypoxanthine linked by the N9 nitrogen to the C1 carbon of ribose. It is an intermediate in the degradation of purines and purine nucleosides to uric acid and in pathways of purine salvage. It also occurs in the anticodon of certain transfer RNA molecules. (Dorland, 28th ed)
Xanthine
A purine base found in most body tissues and fluids, certain plants, and some urinary calculi. It is an intermediate in the degradation of adenosine monophosphate to uric acid, being formed by oxidation of hypoxanthine. The methylated xanthine compounds caffeine, theobromine, and theophylline and their derivatives are used in medicine for their bronchodilator effects. (Dorland, 28th ed)
Purines
Inosine Monophosphate
Inosine 5'-Monophosphate. A purine nucleotide which has hypoxanthine as the base and one phosphate group esterified to the sugar moiety.
Xanthine Oxidase
An iron-molybdenum flavoprotein containing FLAVIN-ADENINE DINUCLEOTIDE that oxidizes hypoxanthine, some other purines and pterins, and aldehydes. Deficiency of the enzyme, an autosomal recessive trait, causes xanthinuria.
Phosphoribosyl Pyrophosphate
The key substance in the biosynthesis of histidine, tryptophan, and purine and pyrimidine nucleotides.
Inosine Nucleotides
Inosine nucleotides are purine nucleotides that contain inosine, a nucleoside with a hypoxanthine base, which can function as a weak agonist at adenosine receptors and play a role in the salvage pathways of nucleic acid metabolism.
Azaguanine
Lesch-Nyhan Syndrome
An inherited disorder transmitted as a sex-linked trait and caused by a deficiency of an enzyme of purine metabolism; HYPOXANTHINE PHOSPHORIBOSYLTRANSFERASE. Affected individuals are normal in the first year of life and then develop psychomotor retardation, extrapyramidal movement disorders, progressive spasticity, and seizures. Self-destructive behaviors such as biting of fingers and lips are seen frequently. Intellectual impairment may also occur but is typically not severe. Elevation of uric acid in the serum leads to the development of renal calculi and gouty arthritis. (Menkes, Textbook of Child Neurology, 5th ed, pp127)
Pentosyltransferases
Adenine
A purine base and a fundamental unit of ADENINE NUCLEOTIDES.
Purine Nucleotides
Purines attached to a RIBOSE and a phosphate that can polymerize to form DNA and RNA.
Purine-Nucleoside Phosphorylase
Nucleobase Transport Proteins
Proteins involved in the transport of nucleobases such as PYRIMIDINES and PURINES across membranes.
Uric Acid
An oxidation product, via XANTHINE OXIDASE, of oxypurines such as XANTHINE and HYPOXANTHINE. It is the final oxidation product of purine catabolism in humans and primates, whereas in most other mammals URATE OXIDASE further oxidizes it to ALLANTOIN.
Guanine
Adenine Phosphoribosyltransferase
Purine-Pyrimidine Metabolism, Inborn Errors
Inborn errors of purine-pyrimidine metabolism refer to genetic disorders resulting from defects in the enzymes responsible for the metabolic breakdown and synthesis of purines and pyrimidines, leading to the accumulation of toxic metabolites or deficiency of necessary nucleotides, causing various clinical manifestations such as neurological impairment, kidney problems, and developmental delays.
Allopurinol
A XANTHINE OXIDASE inhibitor that decreases URIC ACID production. It also acts as an antimetabolite on some simpler organisms.
Thioguanine
Adenosine
Nucleosides
Purine Nucleosides
Purines with a RIBOSE attached that can be phosphorylated to PURINE NUCLEOTIDES.
Thioinosine
Sulfhydryl analog of INOSINE that inhibits nucleoside transport across erythrocyte plasma membranes, and has immunosuppressive properties. It has been used similarly to MERCAPTOPURINE in the treatment of leukemia. (From Martindale, The Extra Pharmacopoeia, 30th ed, p503)
Adenine Nucleotides
Adenine nucleotides are molecules that consist of an adenine base attached to a ribose sugar and one, two, or three phosphate groups, including adenosine monophosphate (AMP), adenosine diphosphate (ADP), and adenosine triphosphate (ATP), which play crucial roles in energy transfer and signaling processes within cells.
Xanthine Dehydrogenase
Allantoin
Guanosine Monophosphate
A guanine nucleotide containing one phosphate group esterified to the sugar moiety and found widely in nature.
6-Mercaptopurine
Hybrid Cells
Nucleoside Transport Proteins
Proteins involved in the transport of NUCLEOSIDES across cellular membranes.
Uracil
Uracil is a nitrogenous base, specifically a pyrimidine derivative, which constitutes one of the four nucleobases in the nucleic acid of RNA (ribonucleic acid), pairing with adenine via hydrogen bonds during base-pairing. (25 words)
Azaserine
Archaeoglobales
Ribonucleosides
Methylthioinosine
6-(Methylthio)-9-beta-D-ribofuranosylpurine. An analog of inosine with a methylthio group replacing the hydroxyl group in the 6-position.
Oxypurinol
A xanthine oxidase inhibitor.
Adenosine Monophosphate
Pentosephosphates
Guanosine
A purine nucleoside that has guanine linked by its N9 nitrogen to the C1 carbon of ribose. It is a component of ribonucleic acid and its nucleotides play important roles in metabolism. (From Dorland, 28th ed)
Dipyridamole
A phosphodiesterase inhibitor that blocks uptake and metabolism of adenosine by erythrocytes and vascular endothelial cells. Dipyridamole also potentiates the antiaggregating action of prostacyclin. (From AMA Drug Evaluations Annual, 1994, p752)
Coformycin
A ribonucleoside antibiotic synergist and adenosine deaminase inhibitor isolated from Nocardia interforma and Streptomyces kaniharaensis. It is proposed as an antineoplastic synergist and immunosuppressant.
N-Glycosyl Hydrolases
Chromatography, High Pressure Liquid
Mutation
DNA Glycosylases
A family of DNA repair enzymes that recognize damaged nucleotide bases and remove them by hydrolyzing the N-glycosidic bond that attaches them to the sugar backbone of the DNA molecule. The process called BASE EXCISION REPAIR can be completed by a DNA-(APURINIC OR APYRIMIDINIC SITE) LYASE which excises the remaining RIBOSE sugar from the DNA.
Thymidine
Thymidine is a pyrimidine nucleoside, consisting of a thymine base linked to a deoxyribose sugar by a β-N1-glycosidic bond, which plays a crucial role in DNA replication and repair processes as one of the four nucleosides in DNA.
Guanine Nucleotides
Guanine nucleotides are cyclic or linear molecules that consist of a guanine base, a pentose sugar (ribose in the cyclic form, deoxyribose in the linear form), and one or more phosphate groups, playing crucial roles in signal transduction, protein synthesis, and regulation of enzymatic activities.
Erythrocytes
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
X Chromosome
Adenosine Deaminase Inhibitors
Drugs that inhibit ADENOSINE DEAMINASE activity.
Adenylosuccinate Synthase
Aminohydrolases
Aminohydrolases are a class of enzymes that catalyze the hydrolysis of various nitrogenous compounds, including proteins, nucleotides, and amines, playing a crucial role in numerous biological processes such as metabolism and signaling.
DNA
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Pyrimidine Nucleotides
Pyrimidines with a RIBOSE and phosphate attached that can polymerize to form DNA and RNA.
Tubercidin
Phosphoglycerate Kinase
Adenosine Kinase
Nucleotides
The monomeric units from which DNA or RNA polymers are constructed. They consist of a purine or pyrimidine base, a pentose sugar, and a phosphate group. (From King & Stansfield, A Dictionary of Genetics, 4th ed)
Sex Chromosomes
The homologous chromosomes that are dissimilar in the heterogametic sex. There are the X CHROMOSOME, the Y CHROMOSOME, and the W, Z chromosomes (in animals in which the female is the heterogametic sex (the silkworm moth Bombyx mori, for example)). In such cases the W chromosome is the female-determining and the male is ZZ. (From King & Stansfield, A Dictionary of Genetics, 4th ed)
Amidophosphoribosyltransferase
Gout
Hereditary metabolic disorder characterized by recurrent acute arthritis, hyperuricemia and deposition of sodium urate in and around the joints, sometimes with formation of uric acid calculi.