Hypoxanthine phosphoribosyltransferase. Medical search

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.

Purine bases related to hypoxanthine, an intermediate product of uric acid synthesis and a breakdown product of adenine catabolism.

A purine and a reaction intermediate in the metabolism of adenosine and in the formation of nucleic acids by the salvage pathway.

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)

An enzyme catalyzing the formation of AMP from adenine and phosphoribosylpyrophosphate. It can act as a salvage enzyme for recycling of adenine into nucleic acids. EC 2.4.2.7.

Enzymes of the transferase class that catalyze the transfer of a pentose group from one compound to another.

The key substance in the biosynthesis of histidine, tryptophan, and purine and pyrimidine nucleotides.

One of the early purine analogs showing antineoplastic activity. It functions as an antimetabolite and is easily incorporated into ribonucleic acids.

Inosine 5'-Monophosphate. A purine nucleotide which has hypoxanthine as the base and one phosphate group esterified to the sugar moiety.

The enzyme catalyzing the formation of orotidine-5'-phosphoric acid (orotidylic acid) from orotic acid and 5-phosphoribosyl-1-pyrophosphate in the course of pyrimidine nucleotide biosynthesis. EC 2.4.2.10.

The female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in human and other male-heterogametic species.

Iodoproteins are proteins that have iodine atoms covalently bonded to them, often as part of thyroid hormones or other biologically active molecules involved in various physiological processes such as metabolism regulation and antioxidant defense systems.

Any cell, other than a ZYGOTE, that contains elements (such as NUCLEI and CYTOPLASM) from two or more different cells, usually produced by artificial CELL FUSION.

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.

An enzyme that catalyzes the formation of nicotinamide mononucleotide (NMN) from nicotinamide and 5-phosphoribosyl-1-pyrophosphate, the rate-limiting step in the biosynthesis of the NAD coenzyme. It is also known as a growth factor for early B-LYMPHOCYTES, or an ADIPOKINE with insulin-mimetic effects (visfatin).

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)

Genetic mechanisms that allow GENES to be expressed at a similar level irrespective of their GENE DOSAGE. This term is usually used in discussing genes that lie on the SEX CHROMOSOMES. Because the sex chromosomes are only partially homologous, there is a different copy number, i.e., dosage, of these genes in males vs. females. In DROSOPHILA, dosage compensation is accomplished by hypertranscription of genes located on the X CHROMOSOME. In mammals, dosage compensation of X chromosome genes is accomplished by random X CHROMOSOME INACTIVATION of one of the two X chromosomes in the female.

An antineoplastic compound which also has antimetabolite action. The drug is used in the therapy of acute leukemia.

An enzyme catalyzing the transfer of a phosphate group from 3-phospho-D-glycerate in the presence of ATP to yield 3-phospho-D-glyceroyl phosphate and ADP. EC 2.7.2.3.

An enzyme that catalyzes the first step of the pathway for histidine biosynthesis in Salmonella typhimurium. ATP reacts reversibly with 5-phosphoribosyl-1-pyrophosphate to yield N-1-(5'-phosphoribosyl)-ATP and pyrophosphate. EC 2.4.2.17.

A purine base and a fundamental unit of ADENINE NUCLEOTIDES.

Glucose-6-Phosphate Dehydrogenase (G6PD) is an enzyme that plays a critical role in the pentose phosphate pathway, catalyzing the oxidation of glucose-6-phosphate to 6-phosphoglucono-δ-lactone while reducing nicotinamide adenine dinucleotide phosphate (NADP+) to nicotinamide adenine dinucleotide phosphate hydrogen (NADPH), thereby protecting cells from oxidative damage and maintaining redox balance.

A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.

An enzyme that catalyzes the formation of N-5'-phosphoribosylanthranilic acid from anthranilate and phosphoribosylpyrophosphate, the first step in tryptophan synthesis in E. coli. It exists in a complex with ANTHRANILATE SYNTHASE in bacteria. EC 2.4.2.18.

Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.

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.

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).

Established cell cultures that have the potential to propagate indefinitely.

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.

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)

Mapping of the KARYOTYPE of a cell.

The rate dynamics in chemical or physical systems.

A group of genetically identical cells all descended from a single common ancestral cell by mitosis in eukaryotes or by binary fission in prokaryotes. Clone cells also include populations of recombinant DNA molecules all carrying the same inserted sequence. (From King & Stansfield, Dictionary of Genetics, 4th ed)

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.

Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.

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)

Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.

Purines attached to a RIBOSE and a phosphate that can polymerize to form DNA and RNA.

Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.

Pentosephosphates are monosaccharides, specifically pentoses, that have a phosphate group attached, playing crucial roles in carbohydrate metabolism, such as being intermediates in the pentose phosphate pathway and serving as precursors for nucleotide synthesis.

In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.

Colorless, odorless crystals that are used extensively in research laboratories for the preparation of polyacrylamide gels for electrophoresis and in organic synthesis, and polymerization. Some of its polymers are used in sewage and wastewater treatment, permanent press fabrics, and as soil conditioning agents.

Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.

Guanine is a purine nucleobase, one of the four nucleobases in the nucleic acid of DNA and RNA, involved in forming hydrogen bonds between complementary base pairs in double-stranded DNA molecules.

3-Carbamoyl-1-beta-D-ribofuranosyl pyridinium hydroxide-5'phosphate, inner salt. A nucleotide in which the nitrogenous base, nicotinamide, is in beta-N-glycosidic linkage with the C-1 position of D-ribose. Synonyms: Nicotinamide Ribonucleotide; NMN.

Purine bases found in body tissues and fluids and in some plants.

Antibiotic substance produced by various Streptomyces species. It is an inhibitor of enzymatic activities that involve glutamine and is used as an antineoplastic and immunosuppressive agent.

An enzyme, involved in the early steps of purine nucleotide biosynthesis, that catalyzes the formation of 5-phosphoribosylamine from glutamine and phosphoribosylpyrophosphate. EC 2.4.2.14.

An enzyme that catalyzes the reaction between a purine nucleoside and orthophosphate to form a free purine plus ribose-5-phosphate. EC 2.4.2.1.

Orotidine-5'-phosphate carboxy-lyase. Catalyzes the decarboxylation of orotidylic acid to yield uridylic acid in the final step of the pyrimidine nucleotide biosynthesis pathway. EC 4.1.1.23.

A guanine nucleotide containing one phosphate group esterified to the sugar moiety and found widely in nature.

Orotic acid, also known as pyrophosphoric acid dihydrate, is a organic compound that plays a role in the biosynthesis of pyrimidines, and elevated levels of orotic acid in urine can indicate certain genetic disorders or liver dysfunction.

The act of injuring one's own body to the extent of cutting off or permanently destroying a limb or other essential part of a body.

Ribose substituted in the 1-, 3-, or 5-position by a phosphoric acid moiety.

6-(Methylthio)-9-beta-D-ribofuranosylpurine. An analog of inosine with a methylthio group replacing the hydroxyl group in the 6-position.

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.

A dyskinesia characterized by an inability to maintain the fingers, toes, tongue, or other body parts in a stable position, resulting in continuous slow, sinusoidal, and flowing involuntary movements. This condition is frequently accompanied by CHOREA, where it is referred to as choreoathetosis. Athetosis may occur as a manifestation of BASAL GANGLIA DISEASES or DRUG TOXICITY. (From Adams et al., Principles of Neurology, 6th ed, p76)

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.

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.

A XANTHINE OXIDASE inhibitor that decreases URIC ACID production. It also acts as an antimetabolite on some simpler organisms.

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)

An enzyme that catalyzes the formation of phosphoribosyl pyrophosphate from ATP and ribose-5-phosphate. EC 2.7.6.1.

Germ cell development in the XXY mouse: evidence that X chromosome reactivation is independent of sexual differentiation. (1/958)

Prior to entry into meiosis, XX germ cells in the fetal ovary undergo X chromosome reactivation. The signal for reactivation is thought to emanate from the genital ridge, but it is unclear whether it is specific to the developing ovary. To determine whether the signals are present in the developing testis as well as the ovary, we examined the expression of X-linked genes in germ cells from XXY male mice. To facilitate this analysis, we generated XXY and XX fetuses carrying X chromosomes that were differentially marked and subject to nonrandom inactivation. This pattern of nonrandom inactivation was maintained in somatic cells but, in XX as well as XXY fetuses, both parental alleles were expressed in germ cell-enriched cell populations. Because testis differentiation is temporally and morphologically normal in the XXY testis and because all germ cells embark upon a male pathway of development, these results provide compelling evidence that X chromosome reactivation in fetal germ cells is independent of the somatic events of sexual differentiation. Proper X chromosome dosage is essential for the normal fertility of male mammals, and abnormalities in germ cell development are apparent in the XXY testis within several days of X reactivation. Studies of exceptional germ cells that survive in the postnatal XXY testis demonstrated that surviving germ cells are exclusively XY and result from rare nondisjunctional events that give rise to clones of XY cells. (+info)

Ialpha exon-replacement mice synthesize a spliced HPRT-C(alpha) transcript which may explain their ability to switch to IgA. Inhibition of switching to IgG in these mice. (2/958)

Antibody class switching is regulated by transcription of unrearranged C(H) genes to produce germline (GL) transcripts which direct the choice of isotype and are required for switching. However, their role is unknown. GL transcripts are initiated at the I exons located upstream of each switch region. Although deletion of the I exon by gene targeting prevents switch recombination to that CH gene, the Ialpha exon can be replaced by an entirely different DNA segment, a minigene driven by the phosphoglycerate kinase (PGK) promoter and encoding hypoxanthine phosphoribosyl transferase (HPRT), oriented in the sense direction, without reducing antibody class switching to IgA. To understand why HPRT substitution of the Ialpha exon does not disrupt switch recombination, we have analyzed the structure of the transcript from the targeted allele in these mice. We identify a spliced transcript in which the HPRT exons are spliced to the C(alpha) gene segments, resulting in a structure similar to normal GL transcripts. The abundance of this transcript is similar to that of the normal alpha GL RNA. We also demonstrate that switching to the four IgG subclasses in B cells from these mice is reduced in comparison to wild-type mice. We discuss the possibility that the strong PGK promoter inserted at the Ig alpha locus may interfere with interaction of the promoters for gamma GL transcripts with the 3' IgH enhancer. (+info)

MSH3 deficiency is not sufficient for a mutator phenotype in Chinese hamster ovary cells. (3/958)

In the yeast Saccharomyces cerevisiae, the mutS homolog protein products MSH3 and MSH6, each in cooperation with MSH2, play well-defined and specific roles in the repair of DNA mismatches and nucleotide loops. The discrete functions of the human homologs hMSH3 and hMSH6 are less clear and current evidence suggests that the substrate specificity of these proteins may be less strict. To determine the role of MSH3 in mammalian mismatch repair, we employed MSH3-deficient Chinese hamster ovary (CHO) cell lines. No significant changes in mutation rate were detected in the MSH3-deficient strain and there were no differences in sensitivity to DNA-damaging agents. Further analysis of hprt mutants did not show a MSH3-dependent shift in the mutant spectrum. Interestingly, thorough examination of four dinucleotide microsatellite regions revealed instability at only one locus in one of the MSH3-deficient cell lines. These data support the idea of a high degree of redundancy in the function of the MutS homologs MSH3 and MSH6, at least with respect to the control of microsatellite instability. (+info)

Hprt mutant frequency and molecular analysis of Hprt mutations in Fischer 344 rats treated with thiotepa. (4/958)

Thiotepa is a bifunctional alkylating anticancer drug that is a rodent carcinogen and a suspected human carcinogen. In order to determine the sensitivity of mutant induction in the Hprt lymphocyte assay for detecting tumorigenic doses of thiotepa, Fischer 344 rats were treated for 4 weeks with thiotepa using a procedure adapted from a carcinogenesis protocol. At various times after beginning the treatment regimen, rats were killed and the lymphocyte Hprt assay was performed on splenic lymphocytes isolated from the animals. The 6-thioguanine-resistant T lymphocyte mutant frequency increased with time during the period of thiotepa exposure and declined slightly thereafter. Significant dose-dependent increases in mutant frequency were found using concentrations of thiotepa that eventually result in lymphoproliferative tumors. Hprt mRNA from mutant lymphocytes was reverse transcribed to cDNA, amplified by PCR and examined for mutations by DNA sequencing. This analysis indicated that the major type of point mutation was G:C-->T:A transversion and that 33% of the mutants contained simple or complex frameshifts. Also, a multiplex PCR performed on DNA from mutant clones that were expanded in vitro indicated that 34% of the clones had deletions in the Hprt gene. These results indicate that the induction of lymphocyte Hprt mutants is a sensitive biomarker for the carcinogenicity of thiotepa and that the types of mutations found in the lymphocyte Hprt gene reflect the kinds of DNA damage produced by thiotepa. (+info)

Expression of the Methanobacterium thermoautotrophicum hpt gene, encoding hypoxanthine (Guanine) phosphoribosyltransferase, in Escherichia coli. (5/958)

The hpt gene from the archaeon Methanobacterium thermoautotrophicum, encoding hypoxanthine (guanine) phosphoribosyltransferase, was cloned by functional complementation into Escherichia coli. The hpt-encoded amino acid sequence is most similar to adenine phosphoribosyltransferases, but the encoded enzyme has activity only with hypoxanthine and guanine. The synthesis of the recombinant enzyme is apparently limited by the presence of the rare arginine codons AGA and AGG and the rare isoleucine AUA codon on the hpt gene. The recombinant enzyme was purified to apparent homogeneity. (+info)

5-azacytidine induces transgene silencing by DNA methylation in Chinese hamster cells. (6/958)

The cytosine analog 5-azacytidine (5-AzaC) is a demethylating agent that is also known to induce mutagenesis in mammalian cells. In this study, the mutagenic potential of this drug was tested in the G10 and G12 transgenic Chinese hamster cell lines, which have a single bacterial gpt gene integrated into the genome at different sites, with its expression driven by a simian virus 40 (SV40) promoter. We show that the mutation frequencies following a 48-h exposure to different concentrations of 5-AzaC were 10 to 20 times higher than those of any of the other numerous mutagens that have been tested in the G10-G12 system. Moreover, the mutation frequencies were much higher in the G10 cell line than in the G12 cells. Detailed molecular analysis of the 6-thioguanine (6-TG)-resistant variants demonstrated that transgene silencing by de novo DNA methylation and increased chromatin condensation in the SV40 promoter was the major factor responsible for this high level of 6-TG resistance. As would be expected, exposure to 5-AzaC lowered the overall genomic DNA methylation levels, but it unexpectedly caused hypermethylation and increased chromatin condensation of the transgene in both the G10 and G12 cell lines. These results provide the first evidence that 5-AzaC may also induce transgene-specific DNA methylation, a phenomenon that can further be used for the elucidation of the mechanism that controls silencing of foreign DNA. (+info)

Point mutations in the guanine phosphoribosyltransferase from Giardia lamblia modulate pyrophosphate binding and enzyme catalysis. (7/958)

Guanine phosphoribosyltransferase (GPRTase) from Giardia lamblia, an enzyme required for guanine salvage and necessary for the survival of this parasitic protozoan, has been kinetically characterized. Phosphoribosyltransfer proceeds through an ordered sequential mechanism common to many related purine phosphoribosyltransferases (PRTases) with alpha-D-5-phosphoribosyl-1-pyrophosphate (PRPP) binding to the enzyme first and guanosine monophosphate (GMP) dissociating last. The enzyme is a highly unique purine PRTase, recognizing only guanine as its purine substrate (K(m) = 16.4 microM) but not hypoxanthine (K(m) > 200 microM) nor xanthine (no reaction). It also catalyzes both the forward (kcat = 76.7 s-1) and reverse (kcat = 5.8.s-1) reactions at significantly higher rates than all the other purine PRTases described to date. However, the relative catalytic efficiencies favor the forward reaction, which can be attributed to an unusually high K(m) for pyrophosphate (PPi) (323.9 microM) in the reverse reaction, comparable only with the high K(m) for PPi (165.5 microM) in Tritrichomonas foetus HGXPRTase-catalyzed reverse reaction. As the latter case was due to the substitution of threonine for a highly conserved lysine residue in the PPi-binding loop [Munagala et al. (1998) Biochemistry 37, 4045-4051], we identified a corresponding threonine residue in G. lamblia GPRTase at position 70 by sequence alignment, and then generated a T70K mutant of the enzyme. The mutant displays a 6.7-fold lower K(m) for PPi with a twofold increase in the K(m) for PRPP. Further attempts to improve PPi binding led to the construction of a T70K/A72G double mutant, which displays an even lower K(m) of 7.9 microM for PPi. However, mutations of the nearby Gly71 to Glu, Arg, or Ala completely inactivate the GPRTase, suggesting the requirement of flexibility in the putative PPi-binding loop for enzyme catalysis, which is apparently maintained by the glycine residue. We have thus tentatively identified the PPi-binding loop in G. lamblia GPRTase, and attributed the relatively higher catalytic efficiency in the forward reaction to the unusual loop structure for poor PPi binding in the reverse reaction. (+info)

Flow cytometric method to isolate round spermatids from mouse testis. (8/958)

The purpose of this study was to isolate pure populations of round spermatids from mouse testis by flow cytometry followed by cell sorting. Cell suspensions from mouse testis were enriched in germ cells by centrifugation on a discontinuous Percoll gradient, then analysed using a FACScalibur flow cytometer measuring the cell size and density. A large and well-delimited population of cells (R1) expected to contain round spermatids was observed on the dot plot diagram. Sorted R1 cells were very homogeneous in size (approximately 11 microns) and displayed the characteristic cytological aspect of round spermatids. Spermatid-specific gene expression was confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of R1 cells using primers for protamine 2 gene (PRM2) and SP-10. A positive signal for SP-10 was obtained with a single cell using nested primers. The 5.5 kb transcript of c-kit, which is not expressed in spermatids, was not detected by nested RT-PCR, excluding a contamination with spermatogonia. Our results clearly established that flow cytometry followed by cell sorting allows the isolation of a highly homogeneous population of round spermatids from the testis. (+info)

Hypoxanthine-guanine phosphoribosyltransferase (HGPRT) is an enzyme that plays a crucial role in the salvage pathway of nucleotide synthesis. This enzyme catalyzes the conversion of hypoxanthine and guanine to their respective nucleotides, inosine monophosphate (IMP) and guanosine monophosphate (GMP), by transferring the phosphoribosyl group from 5-phosphoribosyl-1 pyrophosphate (PRPP) to the purine bases.

HGPRT deficiency is a genetic disorder known as Lesch-Nyhan syndrome, which is characterized by mental retardation, self-mutilation, spasticity, and uric acid overproduction due to the accumulation of hypoxanthine and guanine. This disorder is caused by mutations in the HPRT1 gene, leading to a decrease or absence of HGPRT enzyme activity.

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.

Hypoxanthine is a purine derivative and an intermediate in the metabolic pathways of nucleotide degradation, specifically adenosine to uric acid in humans. It is formed from the oxidation of xanthine by the enzyme xanthine oxidase. In the body, hypoxanthine is converted to xanthine and then to uric acid, which is excreted in the urine. Increased levels of hypoxanthine in the body can be indicative of various pathological conditions, including tissue hypoxia, ischemia, and necrosis.

Lesch-Nyhan Syndrome is a rare X-linked recessive genetic disorder caused by a deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT). This leads to an accumulation of purines, which can result in neurological symptoms and self-injurious behaviors.

The main features of Lesch-Nyhan Syndrome include:

1. Neurological symptoms: These may include delayed development, choreoathetosis (involuntary movements), spasticity, and dystonia (sustained muscle contractions).
2. Self-injurious behaviors: Affected individuals often bite their lips, fingers, and inside of their cheeks, causing significant tissue damage.
3. Intellectual disability: Most individuals with Lesch-Nyhan Syndrome have moderate to severe intellectual disability.
4. Speech and language difficulties: Many affected individuals have difficulty speaking and understanding language.
5. Kidney problems: The accumulation of purines can lead to kidney stones and kidney failure in some cases.
6. Hyperuricemia: Elevated levels of uric acid in the blood (hyperuricemia) are a hallmark of Lesch-Nyhan Syndrome, which can lead to gout and joint damage.

Lesch-Nyhan Syndrome is typically diagnosed through genetic testing and enzyme assays. There is no cure for the disorder, but treatments may include medications to manage symptoms, behavioral interventions, and physical therapy.

Adenine Phosphoribosyltransferase (APRT) is an enzyme that plays a crucial role in the metabolism of purines, specifically adenine, in the body. The enzyme catalyzes the conversion of adenine to AMP (adenosine monophosphate) by transferring a phosphoribosyl group from 5-phosphoribosyl-1-pyrophosphate (PRPP) to adenine.

Deficiency in APRT can lead to a rare genetic disorder known as Adenine Phosphoribosyltransferase Deficiency or APRT Deficiency. This condition results in the accumulation of 2,8-dihydroxyadenine (DHA) crystals in the renal tubules, which can cause kidney stones and chronic kidney disease. Proper diagnosis and management, including dietary modifications and medication, are essential to prevent complications associated with APRT Deficiency.

Pentosyltransferases are a group of enzymes that catalyze the transfer of a pentose (a sugar containing five carbon atoms) molecule from one compound to another. These enzymes play important roles in various biochemical pathways, including the biosynthesis of nucleotides, glycoproteins, and other complex carbohydrates.

One example of a pentosyltransferase is the enzyme that catalyzes the addition of a ribose sugar to form a glycosidic bond with a purine or pyrimidine base during the biosynthesis of nucleotides, which are the building blocks of DNA and RNA.

Another example is the enzyme that adds xylose residues to proteins during the formation of glycoproteins, which are proteins that contain covalently attached carbohydrate chains. These enzymes are essential for many biological processes and have been implicated in various diseases, including cancer and neurodegenerative disorders.

Phosphoribosyl Pyrophosphate (PRPP) is defined as a key intracellular nucleotide metabolite that plays an essential role in the biosynthesis of purine and pyrimidine nucleotides, which are the building blocks of DNA and RNA. PRPP is synthesized from ribose 5-phosphate and ATP by the enzyme PRPP synthase. It contributes a phosphoribosyl group in the conversion of purines and pyrimidines to their corresponding nucleotides, which are critical for various cellular processes such as DNA replication, repair, and gene expression. Abnormal levels of PRPP have been implicated in several genetic disorders, including Lesch-Nyhan syndrome and PRPP synthetase superactivity.

Azaguanine is a type of antimetabolite drug that is used in medical research and treatment. It is a purine analogue, which means it has a similar chemical structure to the natural purine bases adenine and guanine, which are building blocks of DNA and RNA. Azaguanine can be incorporated into the genetic material of cells, interfering with their normal function and replication. It is used in research to study the effects of such interference on cell growth and development.

In clinical medicine, azaguanine has been used as an anticancer drug, although it is not widely used today due to its toxicity and the availability of more effective treatments. It may also have some activity against certain types of parasitic infections, such as leishmaniasis and malaria.

It's important to note that azaguanine is not a commonly used medication and its use should be under the supervision of a medical professional with experience in its administration and management of potential side effects.

Inosine monophosphate (IMP) is a nucleotide that plays a crucial role in the metabolic pathways of energy production and purine synthesis in cells. It is an ester of the nucleoside inosine and phosphoric acid. IMP is an important intermediate in the conversion of adenosine monophosphate (AMP) to guanosine monophosphate (GMP) in the purine nucleotide cycle, which is critical for maintaining the balance of purine nucleotides in the body. Additionally, IMP can be converted back to AMP through the action of the enzyme adenylosuccinate lyase. IMP has been studied for its potential therapeutic benefits in various medical conditions, including neurodegenerative disorders and ischemia-reperfusion injury.

Orotate phosphoribosyltransferase (OPRT) is an enzyme that catalyzes the conversion of orotate to oximine monophosphate (OMP), which is a key step in the biosynthesis of pyrimidines, a type of nucleotide. This enzyme plays a crucial role in the metabolism of nucleic acids, which are the building blocks of DNA and RNA.

The reaction catalyzed by OPRT is as follows:

orotate + phosphoribosyl pyrophosphate (PRPP) -> oximine monophosphate (OMP) + pyrophosphate

Defects in the gene that encodes for OPRT can lead to orotic aciduria, a rare genetic disorder characterized by an accumulation of orotic acid and other pyrimidines in the urine and other body fluids. Symptoms of this condition may include developmental delay, mental retardation, seizures, and megaloblastic anemia.

The X chromosome is one of the two types of sex-determining chromosomes in humans (the other being the Y chromosome). It's one of the 23 pairs of chromosomes that make up a person's genetic material. Females typically have two copies of the X chromosome (XX), while males usually have one X and one Y chromosome (XY).

The X chromosome contains hundreds of genes that are responsible for the production of various proteins, many of which are essential for normal bodily functions. Some of the critical roles of the X chromosome include:

1. Sex Determination: The presence or absence of the Y chromosome determines whether an individual is male or female. If there is no Y chromosome, the individual will typically develop as a female.
2. Genetic Disorders: Since females have two copies of the X chromosome, they are less likely to be affected by X-linked genetic disorders than males. Males, having only one X chromosome, will express any recessive X-linked traits they inherit.
3. Dosage Compensation: To compensate for the difference in gene dosage between males and females, a process called X-inactivation occurs during female embryonic development. One of the two X chromosomes is randomly inactivated in each cell, resulting in a single functional copy per cell.

The X chromosome plays a crucial role in human genetics and development, contributing to various traits and characteristics, including sex determination and dosage compensation.

Iodoproteins are proteins that have iodine atoms chemically bonded to them. This type of modification is often seen in the thyroid hormones, where iodination of the tyrosine residues plays a crucial role in their biological activity. The iodination of proteins can also occur as a result of exposure to certain disinfectants such as iodopovidone (povidone-iodine), which is used for its antimicrobial properties. However, it's important to note that non-specific iodination of proteins can alter their structure and function, and may even lead to the formation of harmful byproducts, so it's not a common practice in biological systems.

I'm sorry for any confusion, but "hybrid cells" is not a standard medical term with a widely accepted or specific definition in the field of medicine. The term "hybrid" is used in various scientific and medical contexts to describe combinations or mixtures of different elements, such as hybridoma cells (a type of fusion cell used in research, created by combining a B cell and a tumor cell) or hybridization (in genetics, the process of combining DNA from two different sources).

Without more specific context, it's difficult to provide an accurate medical definition for "hybrid cells." If you could provide more information about the context in which this term was used, I would be happy to help you further!

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.

Nicotinamide phosphoribosyltransferase (NAMPT) is an enzyme that plays a crucial role in the metabolism of nicotinamide adenine dinucleotide (NAD+), which is a coenzyme found in all living cells and is involved in various cellular processes, including energy production, DNA repair, and gene expression. NAMPT catalyzes the conversion of nicotinamide (a form of vitamin B3) into nicotinamide mononucleotide (NMN), which is then converted into NAD+.

NAMPT has been identified as a key regulator of NAD+ levels in the body, and its activity is associated with various health benefits, such as improved insulin sensitivity, reduced inflammation, and increased lifespan. On the other hand, decreased NAMPT activity has been linked to several age-related diseases, including diabetes, neurodegenerative disorders, and cardiovascular disease. Therefore, NAMPT is an important target for developing therapies aimed at preventing or treating these conditions.

Sex chromosomes, often denoted as X and Y, are one of the 23 pairs of human chromosomes found in each cell of the body. Normally, females have two X chromosomes (46,XX), and males have one X and one Y chromosome (46,XY). The sex chromosomes play a significant role in determining the sex of an individual. They contain genes that contribute to physical differences between men and women. Any variations or abnormalities in the number or structure of these chromosomes can lead to various genetic disorders and conditions related to sexual development and reproduction.

Genetic dosage compensation is a process that evens out the effects of genes on an organism's phenotype (observable traits), even when there are differences in the number of copies of those genes present. This is especially important in cases where sex chromosomes are involved, as males and females often have different numbers of sex chromosomes.

In many species, including humans, females have two X chromosomes, while males have one X and one Y chromosome. To compensate for the difference in dosage, one of the female's X chromosomes is randomly inactivated during early embryonic development, resulting in each cell having only one active X chromosome, regardless of sex. This process ensures that both males and females have similar levels of gene expression from their X chromosomes and helps to prevent an imbalance in gene dosage between the sexes.

Defects in dosage compensation can lead to various genetic disorders, such as Turner syndrome (where a female has only one X chromosome) or Klinefelter syndrome (where a male has two or more X chromosomes). These conditions can result in developmental abnormalities and health issues due to the imbalance in gene dosage.

Thioguanine is a medication that belongs to a class of drugs called antimetabolites. It is primarily used in the treatment of acute myeloid leukemia (AML) and other various types of cancer.

In medical terms, thioguanine is a purine analogue that gets metabolically converted into active thiopurine nucleotides, which then get incorporated into DNA and RNA, thereby interfering with the synthesis of genetic material in cancer cells. This interference leads to inhibition of cell division and growth, ultimately resulting in cell death (apoptosis) of the cancer cells.

It is important to note that thioguanine can also affect normal cells in the body, leading to various side effects. Therefore, it should be administered under the close supervision of a healthcare professional who can monitor its effectiveness and potential side effects.

Phosphoglycerate Kinase (PGK) is an enzyme that plays a crucial role in the glycolytic pathway, which is a series of reactions that convert glucose into pyruvate, producing ATP and NADH as energy-rich compounds. PGK catalyzes the conversion of 1,3-bisphosphoglycerate (1,3-BPG) to 3-phosphoglycerate (3-PG), concomitantly transferring a phosphate group to ADP to form ATP. This reaction is the fourth step in the glycolytic pathway and is reversible under certain conditions.

In humans, there are two isoforms of PGK: PGK1 and PGK2. PGK1 is widely expressed in various tissues, while PGK2 is primarily found in sperm cells. Deficiencies or mutations in the PGK1 gene can lead to a rare metabolic disorder called Phosphoglycerate Kinase Deficiency (PGKD), which can present with hemolytic anemia and neurological symptoms.

ATP phosphoribosyltransferase (ATP-PRT, or adenine phosphoribosyltransferase) is an enzyme involved in the purine nucleotide biosynthesis pathway. The enzyme catalyzes the conversion of ATP and 5-phosphoribosyl-1-pyrophosphate (PRPP) to adenosine monophosphate (AMP) and pyrophosphate (PPi). This reaction is part of the salvage pathway, which recycles purines by converting free purine bases back into nucleotides. A deficiency in ATP-PRT can lead to a rare genetic disorder known as adenine phosphoribosyltransferase deficiency or APRT deficiency, which is characterized by the accumulation of 2,8-dihydroxyadenine crystals in the renal tubules, resulting in kidney stones and potential kidney damage.

Adenine is a purine nucleotide base that is a fundamental component of DNA and RNA, the genetic material of living organisms. In DNA, adenine pairs with thymine via double hydrogen bonds, while in RNA, it pairs with uracil. Adenine is essential for the structure and function of nucleic acids, as well as for energy transfer reactions in cells through its role in the formation of adenosine triphosphate (ATP), the primary energy currency of the cell.

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), also known as Glucosephosphate Dehydrogenase, is an enzyme that plays a crucial role in cellular metabolism, particularly in the glycolytic pathway. It catalyzes the conversion of glyceraldehyde 3-phosphate (G3P) to 1,3-bisphosphoglycerate (1,3-BPG), while also converting nicotinamide adenine dinucleotide (NAD+) to its reduced form NADH. This reaction is essential for the production of energy in the form of adenosine triphosphate (ATP) during cellular respiration. GAPDH has been widely used as a housekeeping gene in molecular biology research due to its consistent expression across various tissues and cells, although recent studies have shown that its expression can vary under certain conditions.

A gene is a specific sequence of nucleotides in DNA that carries genetic information. Genes are the fundamental units of heredity and are responsible for the development and function of all living organisms. They code for proteins or RNA molecules, which carry out various functions within cells and are essential for the structure, function, and regulation of the body's tissues and organs.

Each gene has a specific location on a chromosome, and each person inherits two copies of every gene, one from each parent. Variations in the sequence of nucleotides in a gene can lead to differences in traits between individuals, including physical characteristics, susceptibility to disease, and responses to environmental factors.

Medical genetics is the study of genes and their role in health and disease. It involves understanding how genes contribute to the development and progression of various medical conditions, as well as identifying genetic risk factors and developing strategies for prevention, diagnosis, and treatment.

Anthranilate phosphoribosyltransferase is an enzyme involved in the metabolism of tryptophan, an essential amino acid. This enzyme catalyzes the conversion of anthranilic acid to 1-(o-amino phenyl)phosphoric acid, which is a critical step in the biosynthesis of the aromatic compound known as quinoline.

The reaction catalyzed by anthranilate phosphoribosyltransferase involves the transfer of a phosphoribosyl group from phosphoribosyl pyrophosphate (PRPP) to anthranilic acid, resulting in the formation of 1-(o-amino phenyl)phosphoric acid and pyrophosphate. This reaction is an important part of the tryptophan degradation pathway, which helps regulate the levels of this essential amino acid in the body.

Deficiencies or mutations in anthranilate phosphoribosyltransferase can lead to various metabolic disorders, including a rare genetic condition known as autosomal recessive alkaptonuria (ARA). ARA is characterized by the accumulation of homogentisic acid and its oxidation product, melanin, in various tissues, leading to joint stiffness, darkened skin, and other symptoms.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

Inborn errors of purine-pyrimidine metabolism refer to genetic disorders that result in dysfunctional enzymes involved in the metabolic pathways of purines and pyrimidines. These are essential components of nucleotides, which in turn are building blocks of DNA and RNA.

Inherited as autosomal recessive or X-linked recessive traits, these disorders can lead to an accumulation of toxic metabolites, a deficiency of necessary compounds, or both. Clinical features vary widely depending on the specific enzyme defect but may include neurologic symptoms, kidney problems, gout, and/or immunodeficiency.

Examples of such disorders include Lesch-Nyhan syndrome (deficiency of hypoxanthine-guanine phosphoribosyltransferase), adenosine deaminase deficiency (leading to severe combined immunodeficiency), and orotic aciduria (due to defects in pyrimidine metabolism). Early diagnosis and management are crucial to improve outcomes.

Deoxyribonucleic acid (DNA) is the genetic material present in the cells of organisms where it is responsible for the storage and transmission of hereditary information. DNA is a long molecule that consists of two strands coiled together to form a double helix. Each strand is made up of a series of four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - that are linked together by phosphate and sugar groups. The sequence of these bases along the length of the molecule encodes genetic information, with A always pairing with T and C always pairing with G. This base-pairing allows for the replication and transcription of DNA, which are essential processes in the functioning and reproduction of all living organisms.

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

Cricetinae is a subfamily of rodents that includes hamsters, gerbils, and relatives. These small mammals are characterized by having short limbs, compact bodies, and cheek pouches for storing food. They are native to various parts of the world, particularly in Europe, Asia, and Africa. Some species are popular pets due to their small size, easy care, and friendly nature. In a medical context, understanding the biology and behavior of Cricetinae species can be important for individuals who keep them as pets or for researchers studying their physiology.

Inosine is not a medical condition but a naturally occurring compound called a nucleoside, which is formed from the combination of hypoxanthine and ribose. It is an intermediate in the metabolic pathways of purine nucleotides, which are essential components of DNA and RNA. Inosine has been studied for its potential therapeutic benefits in various medical conditions, including neurodegenerative disorders, cardiovascular diseases, and cancer. However, more research is needed to fully understand its mechanisms and clinical applications.

Karyotyping is a medical laboratory test used to study the chromosomes in a cell. It involves obtaining a sample of cells from a patient, usually from blood or bone marrow, and then staining the chromosomes so they can be easily seen under a microscope. The chromosomes are then arranged in pairs based on their size, shape, and other features to create a karyotype. This visual representation allows for the identification and analysis of any chromosomal abnormalities, such as extra or missing chromosomes, or structural changes like translocations or inversions. These abnormalities can provide important information about genetic disorders, diseases, and developmental problems.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

A clone is a group of cells that are genetically identical to each other because they are derived from a common ancestor cell through processes such as mitosis or asexual reproduction. Therefore, the term "clone cells" refers to a population of cells that are genetic copies of a single parent cell.

In the context of laboratory research, cells can be cloned by isolating a single cell and allowing it to divide in culture, creating a population of genetically identical cells. This is useful for studying the behavior and characteristics of individual cell types, as well as for generating large quantities of cells for use in experiments.

It's important to note that while clone cells are genetically identical, they may still exhibit differences in their phenotype (physical traits) due to epigenetic factors or environmental influences.

Inosine nucleotides are chemical compounds that play a role in the metabolism of nucleic acids, which are the building blocks of DNA and RNA. Inosine is a purine nucleoside that is formed when adenosine (a normal component of DNA and RNA) is deaminated, or has an amino group (-NH2) removed from its structure.

Inosine nucleotides are important in the salvage pathway of nucleotide synthesis, which allows cells to recycle existing nucleotides rather than synthesizing them entirely from scratch. Inosine nucleotides can be converted back into adenosine nucleotides through a process called reversal of deamination.

Inosine nucleotides also have important functions in the regulation of gene expression and in the response to cellular stress. For example, they can act as signaling molecules that activate various enzymes and pathways involved in DNA repair, apoptosis (programmed cell death), and other cellular processes.

Inosine nucleotides have been studied for their potential therapeutic uses in a variety of conditions, including neurological disorders, cancer, and viral infections. However, more research is needed to fully understand their mechanisms of action and potential benefits.

An allele is a variant form of a gene that is located at a specific position on a specific chromosome. Alleles are alternative forms of the same gene that arise by mutation and are found at the same locus or position on homologous chromosomes.

Each person typically inherits two copies of each gene, one from each parent. If the two alleles are identical, a person is said to be homozygous for that trait. If the alleles are different, the person is heterozygous.

For example, the ABO blood group system has three alleles, A, B, and O, which determine a person's blood type. If a person inherits two A alleles, they will have type A blood; if they inherit one A and one B allele, they will have type AB blood; if they inherit two B alleles, they will have type B blood; and if they inherit two O alleles, they will have type O blood.

Alleles can also influence traits such as eye color, hair color, height, and other physical characteristics. Some alleles are dominant, meaning that only one copy of the allele is needed to express the trait, while others are recessive, meaning that two copies of the allele are needed to express the trait.

Xanthine is a purine base, which is a naturally occurring heterocyclic aromatic organic compound. It is formed in the body during the metabolism of purines, and it's a normal intermediate in the breakdown of nucleotides to uric acid. Xanthine is also found in various foods and beverages, such as coffee, tea, and chocolate. In the medical field, xanthine may refer to a class of drugs called xanthine derivatives, which include theophylline and caffeine, that act as bronchodilators and cardiac stimulants.

Erythrocytes, also known as red blood cells (RBCs), are the most common type of blood cell in circulating blood in mammals. They are responsible for transporting oxygen from the lungs to the body's tissues and carbon dioxide from the tissues to the lungs.

Erythrocytes are formed in the bone marrow and have a biconcave shape, which allows them to fold and bend easily as they pass through narrow blood vessels. They do not have a nucleus or mitochondria, which makes them more flexible but also limits their ability to reproduce or repair themselves.

In humans, erythrocytes are typically disc-shaped and measure about 7 micrometers in diameter. They contain the protein hemoglobin, which binds to oxygen and gives blood its red color. The lifespan of an erythrocyte is approximately 120 days, after which it is broken down in the liver and spleen.

Abnormalities in erythrocyte count or function can lead to various medical conditions, such as anemia, polycythemia, and sickle cell disease.

Purine nucleotides are fundamental units of life that play crucial roles in various biological processes. A purine nucleotide is a type of nucleotide, which is the basic building block of nucleic acids such as DNA and RNA. Nucleotides consist of a nitrogenous base, a pentose sugar, and at least one phosphate group.

In purine nucleotides, the nitrogenous bases are either adenine (A) or guanine (G). These bases are attached to a five-carbon sugar called ribose in the case of RNA or deoxyribose for DNA. The sugar and base together form the nucleoside, while the addition of one or more phosphate groups creates the nucleotide.

Purine nucleotides have several vital functions within cells:

1. Energy currency: Adenosine triphosphate (ATP) is a purine nucleotide that serves as the primary energy currency in cells, storing and transferring chemical energy for various cellular processes.
2. Genetic material: Both DNA and RNA contain purine nucleotides as essential components of their structures. Adenine pairs with thymine (in DNA) or uracil (in RNA), while guanine pairs with cytosine.
3. Signaling molecules: Purine nucleotides, such as adenosine monophosphate (AMP) and cyclic adenosine monophosphate (cAMP), act as intracellular signaling molecules that regulate various cellular functions, including metabolism, gene expression, and cell growth.
4. Coenzymes: Purine nucleotides can also function as coenzymes, assisting enzymes in catalyzing biochemical reactions. For example, nicotinamide adenine dinucleotide (NAD+) is a purine nucleotide that plays a critical role in redox reactions and energy metabolism.

In summary, purine nucleotides are essential biological molecules involved in various cellular functions, including energy transfer, genetic material formation, intracellular signaling, and enzyme cofactor activity.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Pentose phosphates are monosaccharides that contain five carbon atoms and one phosphate group. They play a crucial role in various metabolic pathways, including the pentose phosphate pathway (PPP), which is a major source of NADPH and ribose-5-phosphate for the synthesis of nucleotides.

The pentose phosphate pathway involves two main phases: the oxidative phase and the non-oxidative phase. In the oxidative phase, glucose-6-phosphate is converted to ribulose-5-phosphate, producing NADPH and CO2 as byproducts. Ribulose-5-phosphate can then be further metabolized in the non-oxidative phase to produce other pentose phosphates or converted back to glucose-6-phosphate through a series of reactions.

Pentose phosphates are also important intermediates in the synthesis of nucleotides, coenzymes, and other metabolites. Abnormalities in pentose phosphate pathway enzymes can lead to various metabolic disorders, such as defects in erythrocyte function and increased susceptibility to oxidative stress.

Polymerase Chain Reaction (PCR) is a laboratory technique used to amplify specific regions of DNA. It enables the production of thousands to millions of copies of a particular DNA sequence in a rapid and efficient manner, making it an essential tool in various fields such as molecular biology, medical diagnostics, forensic science, and research.

The PCR process involves repeated cycles of heating and cooling to separate the DNA strands, allow primers (short sequences of single-stranded DNA) to attach to the target regions, and extend these primers using an enzyme called Taq polymerase, resulting in the exponential amplification of the desired DNA segment.

In a medical context, PCR is often used for detecting and quantifying specific pathogens (viruses, bacteria, fungi, or parasites) in clinical samples, identifying genetic mutations or polymorphisms associated with diseases, monitoring disease progression, and evaluating treatment effectiveness.

Acrylamides are a type of chemical that can form in some foods during high-temperature cooking processes, such as frying, roasting, and baking. They are created when certain amino acids (asparagine) and sugars in the food react together at temperatures above 120°C (248°F). This reaction is known as the Maillard reaction.

Acrylamides have been classified as a probable human carcinogen by the International Agency for Research on Cancer (IARC), based on studies in animals. However, more research is needed to fully understand the potential health risks associated with acrylamide exposure from food.

Public health organizations recommend limiting acrylamide intake by following some cooking practices such as:

* Avoiding overcooking or burning foods
* Soaking potatoes (which are high in asparagine) in water before frying to reduce the formation of acrylamides
* Choosing raw, unprocessed, or minimally processed foods when possible.

DNA primers are short single-stranded DNA molecules that serve as a starting point for DNA synthesis. They are typically used in laboratory techniques such as the polymerase chain reaction (PCR) and DNA sequencing. The primer binds to a complementary sequence on the DNA template through base pairing, providing a free 3'-hydroxyl group for the DNA polymerase enzyme to add nucleotides and synthesize a new strand of DNA. This allows for specific and targeted amplification or analysis of a particular region of interest within a larger DNA molecule.

Guanine is not a medical term per se, but it is a biological molecule that plays a crucial role in the body. Guanine is one of the four nucleobases found in the nucleic acids DNA and RNA, along with adenine, cytosine, and thymine (in DNA) or uracil (in RNA). Specifically, guanine pairs with cytosine via hydrogen bonds to form a base pair.

Guanine is a purine derivative, which means it has a double-ring structure. It is formed through the synthesis of simpler molecules in the body and is an essential component of genetic material. Guanine's chemical formula is C5H5N5O.

While guanine itself is not a medical term, abnormalities or mutations in genes that contain guanine nucleotides can lead to various medical conditions, including genetic disorders and cancer.

Nicotinamide mononucleotide (NMN) is a bioactive nucleotide that is found in various cells and tissues within the human body. It is a crucial intermediate in the biosynthetic pathway of nicotinamide adenine dinucleotide (NAD+), which is an essential coenzyme involved in numerous cellular processes, including energy metabolism, DNA repair, and gene expression.

NMN can be synthesized within the body from nicotinamide or niacin, and it can also be obtained through dietary sources such as milk, fruits, and vegetables. In recent years, NMN has gained attention in the scientific community for its potential anti-aging effects, as studies have suggested that supplementation with NMN may help to restore NAD+ levels and improve various age-related physiological declines. However, more research is needed to fully understand the therapeutic potential of NMN and its mechanisms of action in humans.

Xanthines are a type of natural alkaloids that are found in various plants, including tea leaves, cocoa beans, and mate. The most common xanthines are caffeine, theophylline, and theobromine. These compounds have stimulant effects on the central nervous system and are often used in medication to treat conditions such as asthma, bronchitis, and other respiratory issues.

Caffeine is the most widely consumed xanthine and is found in a variety of beverages like coffee, tea, and energy drinks. It works by blocking adenosine receptors in the brain, which can lead to increased alertness and reduced feelings of fatigue.

Theophylline is another xanthine that is used as a bronchodilator to treat asthma and other respiratory conditions. It works by relaxing smooth muscles in the airways, making it easier to breathe.

Theobromine is found in cocoa beans and is responsible for the stimulant effects of chocolate. While it has similar properties to caffeine and theophylline, it is less potent and has a milder effect on the body.

It's worth noting that while xanthines can have beneficial effects when used in moderation, they can also cause negative side effects such as insomnia, nervousness, and rapid heart rate if consumed in large quantities or over an extended period of time.

Azaserine is a antineoplastic and antibiotic agent. Its chemical name is O-diazoacetyl-L-serine. It is an analog of the amino acid serine, which inhibits the enzyme necessary for the synthesis of DNA and RNA, thus preventing the growth of cancer cells. Azaserine is used in research but not in clinical medicine due to its high toxicity.

Amidophosphoribosyltransferase is an enzyme involved in the metabolic pathway of purine synthesis. Its systematic name is phosphoribosylamine-phosphate transaminase, and it catalyzes the reaction between phosphoribosyl pyrophosphate (PRPP) and glutamine to produce 5-phosphoribosyl-α-[glutamate-1-formimino]-triose phosphate (GAR) and ammonia.

This enzyme plays a crucial role in the biosynthesis of purine nucleotides, which are essential components of DNA, RNA, and many other important molecules in the body. Deficiencies in this enzyme can lead to serious medical conditions, such as Lesch-Nyhan syndrome, a rare genetic disorder characterized by mental retardation, self-mutilation, spasticity, and an excess of uric acid in the blood (hyperuricemia).

Purine-nucleoside phosphorylase (PNP) is an enzyme that plays a crucial role in the metabolism of purines, which are essential components of nucleic acids (DNA and RNA). The medical definition of 'Purine-Nucleoside Phosphorylase' refers to the physiological function of this enzyme in the human body.

PNP is responsible for catalyzing the phosphorolytic cleavage of purine nucleosides, such as inosine and guanosine, into their respective purine bases (hypoxanthine and guanine) and ribose-1-phosphate. This reaction is essential for the recycling and salvage of purine bases, allowing the body to conserve energy and resources needed for de novo purine biosynthesis.

In a clinical or medical context, deficiencies in PNP activity can lead to serious consequences, particularly affecting the immune system and the nervous system. A genetic disorder called Purine-Nucleoside Phosphorylase Deficiency (PNP Deficiency) is characterized by significantly reduced or absent PNP enzyme activity, leading to an accumulation of toxic purine nucleosides and deoxypurine nucleosides. This accumulation can cause severe combined immunodeficiency (SCID), neurological impairments, and other complications, making it a critical area of study in medical research.

Orotidine-5’-phosphate decarboxylase (ODC) is an enzyme that is involved in the synthesis of pyrimidines, which are essential nucleotides required for the production of DNA and RNA. The gene that encodes this enzyme is called UMPS.

ODC catalyzes the decarboxylation of orotidine-5’-phosphate (OMP) to form uridine monophosphate (UMP), which is a precursor to other pyrimidines such as cytidine triphosphate (CTP) and thymidine triphosphate (TTP). This reaction is the fifth step in the de novo synthesis of pyrimidines.

Defects in the ODC enzyme can lead to a rare genetic disorder called orotic aciduria, which is characterized by an accumulation of orotic acid and orotidine in the urine, as well as neurological symptoms such as developmental delay, seizures, and ataxia. Treatment for this condition typically involves supplementation with uridine and a low-protein diet to reduce the production of excess orotic acid.

Guanosine monophosphate (GMP) is a nucleotide that is a fundamental unit of genetic material in DNA and RNA. It consists of a guanine base, a pentose sugar (ribose in the case of RNA, deoxyribose in DNA), and one phosphate group. GMP plays crucial roles in various biochemical reactions within cells, including energy transfer and signal transduction pathways. Additionally, it is involved in the synthesis of important molecules like nucleic acids, neurotransmitters, and hormones.

Orotic acid, also known as pyrmidine carboxylic acid, is a organic compound that plays a role in the metabolic pathway for the biosynthesis of pyrimidines, which are nitrogenous bases found in nucleotides and nucleic acids such as DNA and RNA. Orotic acid is not considered to be a vitamin, but it is sometimes referred to as vitamin B13 or B15, although these designations are not widely recognized by the scientific community.

In the body, orotic acid is converted into orotidine monophosphate (OMP) by the enzyme orotate phosphoribosyltransferase. OMP is then further metabolized to form uridine monophosphate (UMP), a pyrimidine nucleotide that is an important precursor for the synthesis of RNA and other molecules.

Elevated levels of orotic acid in the urine, known as orotic aciduria, can be a sign of certain genetic disorders that affect the metabolism of pyrimidines. These conditions can lead to an accumulation of orotic acid and other pyrimidine precursors in the body, which can cause a range of symptoms including developmental delays, neurological problems, and kidney stones. Treatment for these disorders typically involves dietary restrictions and supplementation with nucleotides or nucleosides to help support normal pyrimidine metabolism.

Self-mutilation, also known as self-injury or self-harm, refers to the deliberate infliction of pain or damage to one's own body without the intention of committing suicide. It can take many forms, including cutting, burning, scratching, hitting, or piercing the skin. The behavior is often used as a coping mechanism to deal with emotional distress, trauma, or other psychological issues. Self-mutilation can be a sign of serious mental health concerns and should be treated as such. It's important to seek professional help if you or someone you know is engaging in self-harm behaviors.

Ribose monophosphates are organic compounds that play a crucial role in the metabolism of cells, particularly in energy transfer and nucleic acid synthesis. A ribose monophosphate is formed by the attachment of a phosphate group to a ribose molecule, which is a type of sugar known as a pentose.

In biochemistry, there are two important ribose monophosphates:

1. Alpha-D-Ribose 5-Phosphate (ADP-Ribose): This compound serves as an essential substrate in various cellular processes, including DNA repair, chromatin remodeling, and protein modification. The enzyme that catalyzes the formation of ADP-ribose is known as poly(ADP-ribose) polymerase (PARP).
2. Ribulose 5-Phosphate: This compound is a key intermediate in the Calvin cycle, which is the process by which plants and some bacteria convert carbon dioxide into glucose during photosynthesis. Ribulose 5-phosphate is formed from ribose 5-phosphate through a series of enzymatic reactions.

Ribose monophosphates are essential for the proper functioning of cells and have implications in various physiological processes, as well as in certain disease states.

Methylthioinosine is not a widely recognized or used term in medicine, and it does not have a specific medical definition. It is a chemical compound that is formed by the addition of a methylthio group (-CH3S-) to the nucleoside inosine. Inosine is a purine nucleoside that is formed from the deamination of adenosine.

Methylthioinosine has been studied in some laboratory experiments, but it is not commonly used in clinical medicine or treatment. Therefore, it is not a term that most medical professionals would be familiar with.

Xanthine oxidase is an enzyme that catalyzes the oxidation of xanthine to uric acid, which is the last step in purine metabolism. It's a type of molybdenum-containing oxidoreductase that generates reactive oxygen species (ROS) during its reaction mechanism.

The enzyme exists in two interconvertible forms: an oxidized state and a reduced state. The oxidized form, called xanthine oxidase, reduces molecular oxygen to superoxide and hydrogen peroxide, while the reduced form, called xanthine dehydrogenase, reduces NAD+ to NADH.

Xanthine oxidase is found in various tissues, including the liver, intestines, and milk. An overproduction of uric acid due to increased activity of xanthine oxidase can lead to hyperuricemia, which may result in gout or kidney stones. Some medications and natural compounds are known to inhibit xanthine oxidase, such as allopurinol and febuxostat, which are used to treat gout and prevent the formation of uric acid stones in the kidneys.

Athetosis is a medical term that describes a type of involuntary muscle movement. It is characterized by slow, writhing, and continuous movements that can affect the hands, feet, arms, or legs. These movements are not rhythmic and can be interrupted by other voluntary movements. Athetosis is often seen in individuals with certain neurological conditions, such as cerebral palsy or brain injury. It can also be a side effect of some medications. The exact cause of athetosis is not fully understood, but it is believed to result from damage to the basal ganglia, a part of the brain that helps regulate movement. Treatment for athetosis may include physical therapy, medication, or surgery, depending on the underlying cause and severity of the symptoms.

Gout is a type of inflammatory arthritis that occurs when urate crystals accumulate in and around the joints, causing sudden attacks of severe pain, swelling, redness, and tenderness. Urate crystals can form when there are high levels of uric acid in the blood. Uric acid is a waste product that is produced when the body breaks down purines, substances that are found naturally in certain foods, such as steak, organ meats, and seafood. Other foods also promote higher levels of uric acid, such as alcoholic beverages, especially beer, and drinks sweetened with fruit sugar (fructose).

Normally, uric acid dissolves in the blood and passes through the kidneys and out of the body in urine. But sometimes either the body produces too much uric acid or the kidneys excrete too little uric acid. When this happens, uric acid can build up, forming sharp, needle-like urate crystals in a joint or surrounding tissue that cause pain, inflammation and swelling.

Gout most commonly affects the big toe but can also occur in any joint in the body. The symptoms of gout are often acute, occurring suddenly without warning and frequently at night. The attacks are characterized by a rapid onset of pain, swelling, warmth, and redness in the affected joint. An attack of gout can be so painful that it wakes you up from sleep.

Over time, gout can cause permanent damage to the joints and surrounding tissue, resulting in chronic arthritis. If left untreated, gout also can lead to an accumulation of uric acid crystals in the kidneys, which can result in kidney stones.

Uric acid is a chemical compound that is formed when the body breaks down purines, which are substances that are found naturally in certain foods such as steak, organ meats and seafood, as well as in our own cells. After purines are broken down, they turn into uric acid and then get excreted from the body in the urine.

However, if there is too much uric acid in the body, it can lead to a condition called hyperuricemia. High levels of uric acid can cause gout, which is a type of arthritis that causes painful swelling and inflammation in the joints, especially in the big toe. Uric acid can also form crystals that can collect in the kidneys and lead to kidney stones.

It's important for individuals with gout or recurrent kidney stones to monitor their uric acid levels and follow a treatment plan prescribed by their healthcare provider, which may include medications to lower uric acid levels and dietary modifications.

Allopurinol is a medication used to treat chronic gout and certain types of kidney stones. It works by reducing the production of uric acid in the body, which is the substance that can cause these conditions when it builds up in high levels. Allopurinol is a xanthine oxidase inhibitor, meaning it blocks an enzyme called xanthine oxidase from converting purines into uric acid. By doing this, allopurinol helps to lower the levels of uric acid in the body and prevent the formation of new kidney stones or gout attacks.

It is important to note that allopurinol can have side effects, including rash, stomach upset, and liver or kidney problems. It may also interact with other medications, so it is essential to inform your healthcare provider of any other drugs you are taking before starting allopurinol. Your healthcare provider will determine the appropriate dosage and monitoring schedule based on your individual needs and medical history.

Uracil is not a medical term, but it is a biological molecule. Medically or biologically, uracil can be defined as one of the four nucleobases in the nucleic acid of RNA (ribonucleic acid) that is linked to a ribose sugar by an N-glycosidic bond. It forms base pairs with adenine in double-stranded RNA and DNA. Uracil is a pyrimidine derivative, similar to thymine found in DNA, but it lacks the methyl group (-CH3) that thymine has at the 5 position of its ring.

Ribose-Phosphate Pyrophosphokinase (PRPS): It is an enzyme involved in the metabolic pathway of nucleotide synthesis. The systematic name for this enzyme is ribose-5-phosphate:ATP phosphotransferase. This enzyme catalyzes the conversion of ribose-5-phosphate and ATP to ribose-1,5-bisphosphate and AMP, plus inorganic pyrophosphate (PPi).

The reaction is:

ribose-5-phosphate + ATP -> ribose-1,5-bisphosphate + AMP + PPi

This enzyme plays a crucial role in the synthesis of purine nucleotides, which are essential for DNA and RNA synthesis. Deficiency or mutations in this enzyme can lead to serious medical conditions such as hereditary sensory neuropathy (HSN) and Arts syndrome.

Hypoxanthine-guanine phosphoribosyltransferase (HGPRT) is an enzyme encoded in humans by the HPRT1 gene. HGPRT is a transferase ... "Entrez Gene: hypoxanthine phosphoribosyltransferase 1 (Lesch-Nyhan syndrome)". Finette BA, Kendall H, Vacek PM (Aug 2002). " ... Hypoxanthine+phosphoribosyltransferase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Purine ... Some mutations have been linked to gout, the risk of which is increased in hypoxanthine-guanine phosphoribosyltransferase ...

https://en.wikipedia.org/wiki/Hypoxanthine-guanine_phosphoribosyltransferase

Neurocognitive functioning in Lesch-Nyhan disease and partial hypoxanthine-guanine phosphoribosyltransferase deficiency - ... Hypoxanthine-guanine phosphoribosyl transferase regulates early developmental programming of dopamine neurons: implications for ... Neurocognitive functioning in Lesch-Nyhan disease and partial hypoxanthine-guanine phosphoribosyltransferase deficiency. ... Neurocognitive functioning in Lesch-Nyhan disease and partial hypoxanthine-guanine phosphoribosyltransferase deficiency ...

https://www.cambridge.org/core/journals/journal-of-the-international-neuropsychological-society/article/abs/neurocognitive-functioning-in-lesch-nyhan-disease-and-partial-hypoxanthine-guanine-phosphoribosyltransferase-deficiency/5B1A36DC3BDD581042C6F2BF12FD32BC

Protein target information for Hypoxanthine phosphoribosyltransferase (Plasmodium vivax Mauritania I). Find diseases associated ...

https://pubchem.ncbi.nlm.nih.gov/protein/A0A0J9TE27

Restoration of Hypoxanthine Phosphoribosyl Transferase Activity in Mouse 1R Cells After Fusion with Chick-Embryo Fibroblasts ... Reappearance of murine hypoxanthine guanine phosphoribosyl transferase activity in mouse A9 cells after attempted hybridisation ... Reexpression of the rat hypoxanthine phosphoribosyltransferase gene in rat-human hybrids (English) ... The separation of adenine and hypoxanthine-guanine phosphoribosyl transferases isoenzymes by disc gel electrophoresis ...

https://m.wikidata.org/wiki/Q34733360

Access to Hypoxanthine Phosphoribosyltransferase 1 (HPRT1) Genotyping is restricted. Sign up now. ... Access to Hypoxanthine Phosphoribosyltransferase 1 (HPRT1) Genotyping is restricted. Sign up now. ... Access to Hypoxanthine Phosphoribosyltransferase 1 (HPRT1) Genotyping is restricted. Sign up now. ... Access to Hypoxanthine Phosphoribosyltransferase 1 (HPRT1) Genotyping is restricted. Sign up now. ...

https://app.medicaldatabase.com/site/medical-tests/63725c2c-3a96-4561-b851-fa5b414d1b61

Hypoxanthine-Guanine Phosphoribosyl-Transferase Deficiency: Avoid use of mycophenolate mofetil. (5.6). •. Acute Inflammatory ... 5.6 Patients with Hypoxanthine-Guanine Phosphoribosyl-Transferase Deficiency (HGPRT) 5.7 Acute Inflammatory Syndrome Associated ... 5.6 Patients with Hypoxanthine-Guanine Phosphoribosyl-Transferase Deficiency (HGPRT) Mycophenolate mofetil is an inosine ... have Lesch-Nyhan syndrome, Kelley-Seegmiller syndrome, or another rare inherited deficiency hypoxanthine-guanine phosphoribosyl ...

https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=e34c14d1-8d6e-4c21-922d-60ea10fa4b78&type=display

HYPOXANTHINE-GUANINE PHOSPHORIBOSYLTRANSFERASEMagnesium Ion[(2-{[2-(6-Oxo-1,6-Dihydro-9h-Purin-9-Yl)ethyl](2-Phosphonoethyl) ... Oxopurine Phosphoribosyltransferases And Their Pro-drugs As Antimalarial Agents. ... Hypoxanthine-guanine Phosphoribosyltransferase. (Gene symbol: HPRT1). Chemicals and Non-standard biopolymers (12 molecules) ...

https://www.ncbi.nlm.nih.gov/Structure/pdb/4RAQ

... with primer pairs and probe for scleraxis and collagen type I versus hypoxanthine-guanine phosphoribosyltransferase (HPRT) as ...

https://www.mdpi.com/1422-0067/21/2/593

Hypoxanthine phosphoribosyltransferase 1. Sialidase 1 (lysosomal sialidase). ATP-binding cassette, sub-family C (CFTR/MRP), ...

https://www.researchgate.net/publication/313830189_SVMRFE_based_approach_for_prediction_of_most_discriminatory_gene_target_for_type_II_diabetes

Lesch-Nyhan syndrome is caused by the deficiency of the enzyme hypoxanthine-guanine ... division Using Other Organisms of ... Lesch-Nyhan syndrome is caused by the deficiency of the enzyme hypoxanthine-guanine phosphoribosyl transferase (HGPRT). Cells ... a) Hypoxanthine and thymidine. (b) Thymidine. (c) Aminopterin and thymidine. (d) Hypoxanthine, thymidine and aminopterin (HAT ... Lesch-Nyhan syndrome is caused by the deficiency of the enzyme hypoxanthine-guanine phosphoribosyl transferase (HGPRT). Cells ...

https://qna.carrieradda.com/17309/deficiency-hypoxanthine-phosphoribosyl-transferase-deficient-containing-following

... hypoxanthine guanine xanthine phosphoribosyl transferase (HGXPRT) can protect mice against Plasmodium yoelii pRBC challenge in ... Human T cell recognition of the blood stage antigen Plasmodium hypoxanthine guanine xanthine phosphoribosyl transferase (HGXPRT ... Human T cell recognition of the blood stage antigen Plasmodium hypoxanthine guanine xanthine phosphoribosyl transferase (HGXPRT ... BACKGROUND: The Plasmodium purine salvage enzyme, hypoxanthine guanine xanthine phosphoribosyl transferase (HGXPRT) can protect ...

https://www.ndm.ox.ac.uk/publications/61489?ff98dfc6-616f-11ee-82e9-062b13497950

Hypoxanthine guanine phosphoribosyltransferase deficiency, see Lesch-Nyhan syndrome. *Hypoxanthine phosphoribosyltransferase ...

https://medlineplus.gov/genetics/condition-h/

GAPDH, glyceraldehyde 3-phosphate dehydrogenase; HPRT, hypoxanthine-guanine phosphoribosyltransferase; h.p.i, hours post- ... or hypoxanthine-guanine phosphoribosyltransferase (HPRT) expression; fold change was calculated using the ΔΔCt method. All ... hypoxanthine-guanine phosphoribosyltransferase; HRP, horseradish peroxidase; NEC, nasal epithelial cell; NP, nucleoprotein; ORF ...

https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3001728

Hypoxanthine guanine phosphoribosyltransferase (HGPRT) deficiency (Lesch-Nyhan syndrome): This is an inherited X-linked ... These include a complete deficiency of hypoxanthine guanine phosphoribosyltransferase (HGPRT) as in Lesch-Nyhan syndrome, ... HGRPT catalyzes the conversion of hypoxanthine to inosinic acid, in which PRPP serves as the phosphate donor. The deficiency of ...

https://emedicine.medscape.com/article/241767-overview

Hypoxanthine Phosphoribosyltransferase. Blum CA, Xu M, Orner GA, Fong AT, Bailey GS, Stoner GD, Horio DT, Dashwood RH. 2001. ...

https://lpi.oregonstate.edu/biblio?f%5Bauthor%5D=6551&f%5Btg%5D=B&o=asc&s=keyword

hypoxanthine-guanine-phosphoribosyl-transferase (HPRT). Species / strain / cell type:. Chinese hamster lung fibroblasts (V79). ...

https://www.echa.europa.eu/web/guest/registration-dossier/-/registered-dossier/18061/7/7/1

PDB Compounds: (A:) hypoxanthine-guanine phosphoribosyltransferase. SCOPe Domain Sequences for d1yfza1:. Sequence; same for ... PDB Description: novel imp binding in feedback inhibition of hypoxanthine-guanine phosphoribosyltransferase from ... Family c.61.1.1: Phosphoribosyltransferases (PRTases) [53272] (16 proteins). *. Protein Xanthine-guanine PRTase (XPRTase) [ ...

http://scop.berkeley.edu/sid=d1yfza1

The results were normalized to hypoxanthine phosphoribosyltransferase 1 (HPRT1). Relative gene expression was calculated as 2− ...

https://www.frontiersin.org/articles/10.3389/fncel.2015.00250/full

Data from five to seven mice per genotype (mean±s.e.m.) are given as relative to hypoxanthine phosphoribosyltransferase (HPRT) ... Data are given as relative to hypoxanthine phosphoribosyltransferase (HPRT) expression (mean±range) from two independent ... are given as relative to hypoxanthine phosphoribosyltransferase (HPRT) expression. *P≤0.05; **P≤0.01; ***P≤0.001 (Mann-Whitney ... are given as relative to hypoxanthine phosphoribosyltransferase (HPRT) expression. *P≤0.05; **P≤0.01; ***P≤0.001 (Mann-Whitney ...

https://www.nature.com/articles/mi201798?error=cookies_not_supported&code=ca888c78-bec7-491d-a2c4-76ef55a8e695

Hypoxanthine guanine phosphoribosyltransferase complete deficiency. *Hypoxanthine guanine phosphoribosyltransferase deficiency ... Lesch-Nyhan syndrome (LNS) is the most severe form of hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency (see ... Several neurotransmitter disorders and a toxic effect of hypoxanthine excess have been advocated. ...

https://www.orpha.net/consor/cgi-bin/Disease_Search.php?lng=EN&data_id=197&Disease_Disease_Search_diseaseGroup=Lesch-Nyhan-syndrome&Disease_Disease_Search_diseaseType=Pat&Disease

2. Hypoxanthine-guanine phosphoribosyltransferase. General function:. Involved in hypoxanthine phosphoribosyltransferase ... Converts guanine to guanosine monophosphate, and hypoxanthine to inosine monophosphate. Transfers the 5-phosphoribosyl group ...

https://hmdb.ca/metabolites/HMDB0060412

... hypoxanthine phosphoribosyl transferase 1, Uniprot P00492; 0.277), HBS1L (HBS1-like protein, Uniprot Q9Y450; 0.184), OAZ1 ( ...

https://www.biorxiv.org/content/10.1101/155697v1.full

... hypoxanthine phosphoribosyltransferase 1), 15-19: RPL13A (ribosomal protein L13a), 20: RPL32 (ribosomal protein L32), 21: SDHA ...

https://bmcgenomics.biomedcentral.com/articles/10.1186/1471-2164-8-140

have Lesch-Nyhan or Kelley-Seegmiller syndrome or another rare inherited deficiency hypoxanthine-guanine phosphoribosyl-transferase ...

https://dailymed.nlm.nih.gov/dailymed/medguide.cfm?setid=56428c8f-8a4b-4cbf-93f1-28d8b5cfb51a

New Mutation Affecting Hypoxanthine Phosphoribosyltransferase Responsible for Severe Tophaceous Gout CLÉMENT LAHAYE, FRANCK ...

https://www.jrheum.org/content/41/6

If you have Lesch-Nyhan or Kelley-Seegmiller syndrome or a rare inherited deficiency of hypoxanthine-guanine phosphoribosyl-transferase ...

https://www.drugs.com/cdi/cellcept-mycophenolate-mofetil-tablets.html

Human Erythrocytic Hypoxanthine-Guanine Phosphoribosyltransferase: Effect of pH on the Enzymatic Reaction CHONG M. KONG and R. ...

https://molpharm.aspetjournals.org/content/10/4

Differential Distortion of Purine Substrates by Human and Plasmodium falciparum Hypoxanthine-Guanine Phosphoribosyltransferase ...

https://www.ncbs.res.in/publications?page=7&%3Bamp%3Bs=title&%3Bamp%3Bo=asc&%3Bamp%3Bf%5Bauthor%5D=1254&%3Bf%5Bauthor%5D=1470&f%5Bauthor%5D=383&s=year&o=asc

HPRT Phosphoribosyl Guanine HPRT1 HGPRT Deficiency Enzyme Mutations Purine Mutagenesis Lesch Nyhan Hybridoma Levels

Lesch-Nyhan disease (LND) is a rare, X-linked genetic disorder that involves the nearly complete absence of an enzyme (hypoxanthine-guanine phosphoribosyltransferase, or HPRT) that is essential for purine salvage. (cambridge.org)
Lesch-Nyhan syndrome (LNS) is the most severe form of hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency (see this term), a hereditary disorder of purine metabolism, and is associated with uric acid overproduction (UAO), neurological troubles, and behavioral problems. (orpha.net)
Lesch-Nyhan syndrome (LNS) is a rare, inherited disorder caused by a deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT). (brainfacts.org)
OBJECTIVES--To find whether a relation exists between estimated levels of exposure to radon and its progeny and mutations in hypoxanthine phosphoribosyl transferase (HPRT) and glycophorin A in a cohort of former uranium miners. (bmj.com)
HPRT deficiency results in failure of the salvage pathway for hypoxanthine and guanine. (msdmanuals.com)
Hypoxanthine phosphoribosyl transferase ( HPRT ) gene has been used for studies of the mutagenic effect of EO but not for PO. (who.int)
[ 1 ] The enzymatic defect associated with Lesch-Nyhan disease, deficiency of the enzyme hypoxanthine-guanine phosphoribosyl transferase (HPRT), was discovered by Seegmiller and colleagues in 1967. (medscape.com)
Hypoxanthine-guanine phosphoribosyl transferase (HPRT) normally plays a key role in the recycling of the purine bases, hypoxanthine and guanine, into the purine nucleotide pools (see the image below). (medscape.com)

In this role, it catalyzes the reaction between guanine and phosphoribosyl pyrophosphate (PRPP) to form GMP, or between hypoxanthine and phosphoribosyl pyrophosphate (PRPP) to form inosine monophosphate. (wikipedia.org)
Lesch-Nyhan syndrome is caused by the deficiency of the enzyme hypoxanthine-guanine phosphoribosyl transferase (HGPRT). (carrieradda.com)
Human T cell recognition of the blood stage antigen Plasmodium hypoxanthine guanine xanthine phosphoribosyl transferase (HGXPRT) in acute malaria. (ox.ac.uk)
BACKGROUND: The Plasmodium purine salvage enzyme, hypoxanthine guanine xanthine phosphoribosyl transferase (HGXPRT) can protect mice against Plasmodium yoelii pRBC challenge in a T cell-dependent manner and has, therefore, been proposed as a novel vaccine candidate. (ox.ac.uk)
If you have Lesch-Nyhan or Kelley-Seegmiller syndrome or a rare inherited deficiency of hypoxanthine-guanine phosphoribosyl-transferase (HGPRT). (drugs.com)

Hypoxanthine-guanine phosphoribosyltransferase (HGPRT) is an enzyme encoded in humans by the HPRT1 gene. (wikipedia.org)
HGPRT is a transferase that catalyzes conversion of hypoxanthine to inosine monophosphate and guanine to guanosine monophosphate. (wikipedia.org)
Some mutations have been linked to gout, the risk of which is increased in hypoxanthine-guanine phosphoribosyltransferase deficiency. (wikipedia.org)
Differential Distortion of Purine Substrates by Human and Plasmodium falciparum Hypoxanthine-Guanine Phosphoribosyltransferase to Catalyse the Formation of Mononucleotides. (ncbs.res.in)

Access to Hypoxanthine Phosphoribosyltransferase 1 (HPRT1) Genotyping is restricted. (medicaldatabase.com)

The explanation: HGPRT deficient cells in the medium containing all three hypoxanthine, thymidine and aminopterin. (carrieradda.com)

Some mutations have been linked to gout, the risk of which is increased in hypoxanthine-guanine phosphoribosyltransferase deficiency. (wikipedia.org)
HPRT1 gene mutations that cause Lesch-Nyhan syndrome result in a severe shortage (deficiency) or complete absence of hypoxanthine phosphoribosyltransferase 1. (nih.gov)
For unknown reasons, a deficiency of hypoxanthine phosphoribosyltransferase 1 is associated with low levels of a chemical messenger in the brain called dopamine . (nih.gov)

The HPRT1 gene provides instructions for producing an enzyme called hypoxanthine phosphoribosyltransferase 1. (medlineplus.gov)
The HPRT1 gene provides instructions for making an enzyme called hypoxanthine phosphoribosyltransferase 1. (nih.gov)
PNP is an enzyme in the purine salvage pathway that metabolizes inosine and guanosine to hypoxanthine. (medscape.com)

Characterization of in vivo somatic mutations at the hypoxanthine phosphoribosyltransferase gene of a human control population. (nih.gov)

The 2.0 A structure of malarial purine phosphoribosyltransferase in complex with a transition-state analogue inhibitor. (nih.gov)

The role for an invariant aspartic acid in hypoxanthine phosphoribosyltransferases is examined using saturation mutagenesis, functional analysis, and X-ray crystallography. (expasy.org)

However, it is unclear how a shortage of hypoxanthine phosphoribosyltransferase 1 causes the neurological and behavioral problems characteristic of Lesch-Nyhan syndrome. (nih.gov)

ClonaCell™‐HY Medium D without HAT is a semi-solid methylcellulose-based medium that does not contain any selection agents such as HAT (hypoxanthine, aminopterin, and thymidine), enabling alternative hybridoma or myeloma selection methods to be used. (stemcell.com)

Individuals with this condition have lower than normal levels of hypoxanthine phosphoribosyltransferase 1. (medlineplus.gov)

Anatomy6

Organisms1

Diseases5

Chemicals and Drugs42

Analytical, Diagnostic and Therapeutic Techniques and Equipment2

Psychiatry and Psychology1

Phenomena and Processes8

Information Science2

Germ cell development in the XXY mouse: evidence that X chromosome reactivation is independent of sexual differentiation. (1/958)

Ialpha exon-replacement mice synthesize a spliced HPRT-C(alpha) transcript which may explain their ability to switch to IgA. Inhibition of switching to IgG in these mice. (2/958)

MSH3 deficiency is not sufficient for a mutator phenotype in Chinese hamster ovary cells. (3/958)

Hprt mutant frequency and molecular analysis of Hprt mutations in Fischer 344 rats treated with thiotepa. (4/958)

Expression of the Methanobacterium thermoautotrophicum hpt gene, encoding hypoxanthine (Guanine) phosphoribosyltransferase, in Escherichia coli. (5/958)

5-azacytidine induces transgene silencing by DNA methylation in Chinese hamster cells. (6/958)

Point mutations in the guanine phosphoribosyltransferase from Giardia lamblia modulate pyrophosphate binding and enzyme catalysis. (7/958)

Flow cytometric method to isolate round spermatids from mouse testis. (8/958)

Hypoxanthine Phosphoribosyltransferase

Hypoxanthines

Hypoxanthine

Lesch-Nyhan Syndrome

Adenine Phosphoribosyltransferase

Pentosyltransferases

Phosphoribosyl Pyrophosphate

Azaguanine

Inosine Monophosphate

Orotate Phosphoribosyltransferase

X Chromosome

Iodoproteins

Hybrid Cells

Purines

Nicotinamide Phosphoribosyltransferase

Sex Chromosomes

Dosage Compensation, Genetic

Thioguanine

Phosphoglycerate Kinase

ATP Phosphoribosyltransferase

Adenine

Glucosephosphate Dehydrogenase

Genes

Anthranilate Phosphoribosyltransferase

Mutation

Purine-Pyrimidine Metabolism, Inborn Errors

DNA

Cell Line

Base Sequence

Cricetinae

Inosine

Karyotyping

Kinetics

Clone Cells

Inosine Nucleotides

Alleles

Xanthine

Erythrocytes

Purine Nucleotides

Molecular Sequence Data

Pentosephosphates

Polymerase Chain Reaction

Acrylamides

DNA Primers

Guanine

Nicotinamide Mononucleotide

Xanthines

Azaserine

Amidophosphoribosyltransferase

Purine-Nucleoside Phosphorylase

Orotidine-5'-Phosphate Decarboxylase

Guanosine Monophosphate

Orotic Acid

Self Mutilation

Ribosemonophosphates

Methylthioinosine

Xanthine Oxidase

Athetosis

Gout

Uric Acid

Allopurinol

Uracil

Ribose-Phosphate Pyrophosphokinase

Germ cell development in the XXY mouse: evidence that X chromosome reactivation is independent of sexual differentiation. (1/958)

Ialpha exon-replacement mice synthesize a spliced HPRT-C(alpha) transcript which may explain their ability to switch to IgA. Inhibition of switching to IgG in these mice. (2/958)

MSH3 deficiency is not sufficient for a mutator phenotype in Chinese hamster ovary cells. (3/958)

Hprt mutant frequency and molecular analysis of Hprt mutations in Fischer 344 rats treated with thiotepa. (4/958)

Expression of the Methanobacterium thermoautotrophicum hpt gene, encoding hypoxanthine (Guanine) phosphoribosyltransferase, in Escherichia coli. (5/958)

5-azacytidine induces transgene silencing by DNA methylation in Chinese hamster cells. (6/958)

Point mutations in the guanine phosphoribosyltransferase from Giardia lamblia modulate pyrophosphate binding and enzyme catalysis. (7/958)

Flow cytometric method to isolate round spermatids from mouse testis. (8/958)

Hypoxanthine-guanine phosphoribosyltransferase - Wikipedia

Neurocognitive functioning in Lesch-Nyhan disease and partial hypoxanthine-guanine phosphoribosyltransferase deficiency |...

Hypoxanthine phosphoribosyltransferase (Plasmodium vivax Mauritania I) | Protein Target - PubChem

Reexpression of the rat hypoxanthine phosphoribosyltransferase gene in rat-human hybrids - Wikidata

Hypoxanthine Phosphoribosyltransferase 1 (HPRT1) Genotyping

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