Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Molecular and immunological comparison of human dihydropteridine reductase in liver, cultured fibroblasts and continuous lymphoid cells.

ABSTRACT: An antiserum was raised in a rabbit against highly purified human liver dihydropteridine reductase (EC 1.6.99.7). Dihydropteridine reductase from human liver, in human cultured fibroblasts and in continuous lymphoid cells all showed identical antigenic properties. The structural characteristics of the reductase from these three sources were further compared by the use of high-precision two-dimensional polyacrylamide-gel electrophoresis. The enzyme from radiolabelled fibroblasts and continuous lymphoid cells was isolated by immunoprecipitation or by affinity chromatography and compared with the purified liver enzyme. Two major polypeptide species were resolved, and polypeptides from all three sources co-migrated identically. Indirect evidence is presented indicating that one of the polypeptide species may have been derived from the other via a post-translational modification. These results support the concept that the same structural gene(s) encodes for dihydropteridine reductase in human liver, fibroblasts and lymphocytes.

SUBMITTER: Firgaira FA

PROVIDER: S-EPMC1163053 | biostudies-other | 1981 Jul

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Isolation and characterization of dihydropteridine reductase from human liver.

Project description:Dihydropteridine reductase (EC 1.6.99.7) was purified from human liver obtained at autopsy by a three-step chromatographic procedure with the use of (1) a naphthoquinone affinity adsorbent, (2) DEAE-Sephadex and (3) CM-Sephadex. The enzyme was typically purified 1000-fold with a yield of 25%. It gave a single band on non-denaturing and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, and showed one spot on two-dimensional gel electrophoresis. The molecular weight of the enzyme was determined to be 50000 by sedimentation-equilibrium analysis and 47500 by gel filtration. On sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, a single subunit with mol.wt. 26000 was observed. A complex of dihydropteridine reductase with NADH was observed on gel electrophoresis. The isoelectric point of the enzyme was estimated to be pH 7.0. Amino acid analysis showed a residue composition similar to that seen for the sheep and bovine liver enzymes. The enzyme showed anomalous migration in polyacrylamide-gel electrophoresis. A Ferguson plot indicated that this behaviour is due to a low net charge/size ratio of the enzyme under the electrophoretic conditions used. The kinetic properties of the enzyme with tetrahydrobiopterin, 2-amino-4-hydroxy-6,7-dimethyl-5,6,7,8-tetrahydropteridine, NADH and NADPH are compared, and the effects of pH, temperature and a number of different compounds on catalytic activity are presented.

| S-EPMC1163052 | biostudies-other

Dihydropteridine reductase deficiency and treatment with tetrahydrobiopterin: a case report.

Project description:Dihydropteridine reductase (DHPR) deficiency is a genetic disorder of tetrahydrobiopterin (BH4) regeneration and may present with hyperphenylalaninemia, microcephaly, hypotonia, mental retardation, and convulsions. BH4 is an essential cofactor for the hydroxylation of aromatic amino acids and a deficiency of BH4 results in decreased synthesis of dopamine and serotonin. We present a 27-month-old female patient with DHPR deficiency who was treated with L-dopa/carbidopa (2 mg/kg, four times per day), 5-hydroxytryptophan (2 mg/kg, four times per day), folinic acid (10 mg/day), and BH4 supplementation (20 mg/kg, twice a day). Although remarkable clinical improvement with normal plasma phenylalanine (Phe) levels and increased phenylalanine tolerance was noted 1 month after the treatment, CSF neurotransmitter metabolites did not improve. BH4 supplementation was increased to 40 mg/kg/day and the CSF study was repeated 1 month later. There was no significant change of CSF neurotransmitters, BH4 or BH2 levels but plasma Phe level was within normal range. Surprisingly, she had developmental improvement noted at 1-month and 3-month visits following an augmented neurotransmitter and BH4 treatment. She was able to pull herself to the standing position and sit down on her own. She was also noted to be more alert and responsive following treatment. Her expressive language did not improve, although her receptive language was markedly improved. The above treatment improved patient's clinical findings, normalized blood Phe levels, and increased Phe tolerance in the diet, but neither 20 nor 40 mg/kg/day BH4 supplementation corrected neurotransmitter or BH4 levels or increased BH2 level in CSF. Further studies are needed to find the optimal management plan for patients with DHPR deficiency.

| S-EPMC3755580 | biostudies-literature

Crystallization and preliminary characterization of dihydropteridine reductase from Dictyostelium discoideum.

Project description:Dihydropteridine reductase from Dictyostelium discoideum (dicDHPR) can produce D-threo-BH(4) [6R-(1'R,2'R)-5,6,7,8-tetrahydrobiopterin], a stereoisomer of L-erythro-BH(4), in the last step of tetrahydrobiopterin (BH(4)) recycling. In this reaction, DHPR uses NADH as a cofactor to reduce quinonoid dihydrobiopterin back to BH(4). To date, the enzyme has been purified to homogeneity from many sources. In this report, the dicDHPR-NAD complex has been crystallized using the hanging-drop vapour-diffusion method with PEG 3350 as a precipitant. Rectangular-shaped crystals were obtained. Crystals grew to maximum dimensions of 0.4 x 0.6 x 0.1 mm. The crystal belonged to space group P2(1), with unit-cell parameters a = 49.81, b = 129.90, c = 78.76 A, beta = 100.00 degrees , and contained four molecules in the asymmetric unit, forming two closely interacting dicDHPR-NAD dimers. Diffraction data were collected to 2.16 A resolution using synchrotron radiation. The crystal structure has been determined using the molecular-replacement method.

| S-EPMC2581689 | biostudies-literature

Heterogeneity of the molecular defect in human dihydropteridine reductase deficiency.

Project description:Radioimmunoassay, immunoprecipitation, affinity chromatography and two-dimensional gel electrophoresis were used to test cultured cells from three families with dihydropteridine reductase deficiency for a catalytically incompetent product of the mutant gene. No mutant enzyme was detected in one dihydropteridine reductase-deficient homozygote or in her parents. A second homozygote and both her parents had easily detectable concentrations of inactive mutant enzyme. In a third family one parent fitted into each of these categories.

| S-EPMC1163317 | biostudies-other

Sapropterin dihydrochloride therapy in dihydropteridine reductase deficiency: Insight from the first case with molecular diagnosis in Brazil.

Project description:Tetrahydrobiopterin (BH4) is a cofactor that participates in the biogenesis reactions of a variety of biomolecules, including l-tyrosine, l-3,4-dihydroxyphenylalanine, 5-hydroxytryptophan, nitric oxide, and glycerol. Dihydropteridine reductase (DHPR, EC 1.5.1.34) is an enzyme involved in the BH4 regeneration. DHPR deficiency (DHPRD) is an autosomal recessive disorder, leading to severe and progressive neurological manifestations, which cannot be exclusively controlled by l-phenylalanine (l-Phe) restricted diet. In fact, the supplementation of neurotransmitter precursors is more decisive in the disease management, and the administration of sapropterin dihydrochloride may also provide positive effects. From the best of our knowledge, there is limited information regarding DHPRD in the past 5 years in the literature. Here, we describe the medical journey of the first patient to have DHPRD confirmed by molecular diagnostic methods in Brazil. The patient presented with two pathogenic variants of the quinoid dihydropteridine reductase (QDPR) gene-which codes for the DHPR protein, one containing the in trans missense mutation c.515C>T (pPro172Leu) in exon 5 and the other containing the same type of mutation in the exon 7 (c.635T>C [p.Phe212Ser]). The authors discuss their experience with sapropterin dihydrochloride for the treatment of DHPRD in this case report.

| S-EPMC8411105 | biostudies-literature

Prognostic and Immunological Potential of Ribonucleotide Reductase Subunits in Liver Cancer.

Project description:BackgroundRibonucleotide reductase (RR) consists of two subunits, the large subunit RRM1 and the small subunit (RRM2 or RRM2B), which is essential for DNA replication. Dysregulations of RR were implicated in multiple types of cancer. However, the abnormal expressions and biologic functions of RR subunits in liver cancer remain to be elucidated.MethodsTCGA, HCCDB, CCLE, HPA, cBioPortal, and GeneMANIA were utilized to perform bioinformatics analysis of RR subunits in the liver cancer. GO, KEGG, and GSEA were used for enrichment analysis.ResultsThe expressions of RRM1, RRM2, and RRM2B were remarkably upregulated among liver cancer tissue both in mRNA and protein levels. High expression of RRM1 and RRM2 was notably associated with high tumor grade, high stage, short overall survival, and disease-specific survival. Enrichment analyses indicated that RRM1 and RRM2 were related to DNA replication, cell cycle, regulation of nuclear division, DNA repair, and DNA recombination. Correlation analysis indicated that RRM1 and RRM2 were significantly associated with several subsets of immune cell, including Th2 cells, cytotoxic cells, and neutrophils. RRM2B expression was positively associated with immune score and stromal score. Chemosensitivity analysis revealed that sensitivity of nelarabine was positively associated with high expressions of RRM1 and RRM2. The sensitivity of rapamycin was positively associated with high expressions of RRM2B.ConclusionOur findings demonstrated high expression profiles of RR subunits in liver cancer, which may provide novel insights for predicting the poor prognosis and increased chemosensitivity of liver cancer in clinic.

| S-EPMC9883104 | biostudies-literature

Inhibition of dihydropteridine reductase by dopamine.

Project description:Dihydropteridine reductase has been purified 900-fold from rat liver. Dopamine inhibited the enzyme up to 50% at a concentration of 0.11mm. In the presence of dopamine the enzyme gave non-hyperbolic v-against-[S] plots. This enzyme may have a role in control of dopamine biosynthesis.

| S-EPMC1162951 | biostudies-other

Genome sequencing identifies a homozygous inversion disrupting QDPR as a cause for dihydropteridine reductase deficiency.

Project description:BACKGROUND:Dihydropteridine reductase (DHPR) is one of the key enzymes for maintaining in the organism the supply of tetrahydrobiopterin (BH4 ), an essential cofactor for aromatic amino acid hydroxylases. Its dysfunction causes the condition of hyperphenylalaninemia together with the lack of neurotransmitters. METHODS:We report a patient with biochemically diagnosed DHPR deficiency, with extensive molecular investigations undertaken to detect variations in quinoid dihydropteridine reductase (QDPR) gene. Sanger sequencing of QDPR coding regions, exome sequencing, QDPR mRNA PCR, and karyotyping were followed by trio genome sequencing. RESULTS:Short-read genome sequencing revealed a homozygous 9-Mb inversion disrupting QDPR. Structural variant breakpoints in chromosome 4 were located to intron 2 of QDPR at Chr4(GRCh38):g.17505522 and in intron 8 of the ACOX3 gene, Chr4(GRCh38):g.8398067). Both nonrelated parents carried the variant in heterozygous state. The inversion was not present in gnomAD structural variant database. CONCLUSION:Identification of the exact breakpoints now allows further straightforward molecular genetic testing of potential carriers of the inversion. This study extends the pathogenic variant spectrum of DHPR deficiency and highlights the role of structural variants in recessive metabolic disorders. To our knowledge, this is the first report on a large, canonical (rather than complex) homozygous pathogenic inversion detected by genome sequencing.

| S-EPMC7196484 | biostudies-literature

High prolactin levels in dihydropteridine reductase deficiency: A sign of therapy failure or additional pathology?

Project description:We report the case of a 22-year-old man with a diagnosis of dihydropteridine reductase (DHPR) deficiency who progressively developed movement disorders and epilepsy. Despite L-Dopa supplementation the patient continued to show high prolactin levels, with a discrepancy between the neurological clinical picture and the hormonal biochemical levels. For this reason, other potential causes were ruled out by performing a cerebral magnetic resonance imaging, which demonstrated a solid lesion in the pituitary gland strongly suggestive of a prolactinoma. As the association between metabolic disorders affecting biogenic amine synthesis and prolactinoma has not been previously reported in humans, this report suggests that a critical evaluation of the use of prolactin as a guide for therapy dosage should be made in patients with DHPR deficiency disorders.

| S-EPMC8411106 | biostudies-literature

New pteridine substrates for dihydropteridine reductase and horseradish peroxidase.

Project description:The oxidation of 4,5-diaminopyrimidin-6(1H)-one, 5,6,7,8-tetrahydropteridin-4(3H)-one, its 6-methyl and cis-6,7-dimethyl derivatives, and 6-methyl- and cis-6-7-dimethyl-5,6,7,8-tetrahydropterins, by horseradish peroxidase/H2O2 is enzymic and follows Michaelis-Menten kinetics, and its Km and kcat. values were determined. This oxidation of 5,6,7,8-tetrahydropterins produces quinonoid dihydropterins of established structure, and they are known to be specific substrates for dihydropteridine reductase. By analogy the peroxidase/H2O2 oxidation of the 5,6,7,8-tetrahydropteridin-4(3H)-ones should produce similar quinonoid dihydro species. The quinonoid species derived from 5,6,7,8-tetrahydropteridin-4(3H)-one and its 6-methyl and cis-6,7-dimethyl derivatives are shown to be viable substrates for human brain dihydropteridine reductase, and apparent Km and Vmax. values are reported.

| S-EPMC1146570 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data