pterins

Segawa syndrome usually manifests as dystonia, disturbance of gait with fatigue, and may be confused with spasticity. Also known as dopamine-responsive dystonia (DRD), it should be considered in any child who presents with paroxysmal or progressive hypertonia of unknown etiology, which responds dramatically to levodopa. It is a clinical diagnosis, but the level of pterins in cerebrospinal fluid and guanosine triphosphate cyclohydrolase-1 (GTCH 1) gene mutation testing done by molecular genetic testing are confirmatory...

INTRODUCTION: Sepiapterin reductase deficiency (SRD) is an exceedingly rare neurotransmitter disease caused by an enzyme error involved in the synthesis of tetrahydrobiopterin (BH4). It has been described in nearly 60 cases so far. The clinical manifestations include motor and speech delay, axial hypotonia, dystonia, weakness, oculogyric crises, diurnal fluctuation, and improvement of symptoms during sleep. Molecular genetic analysis can demonstrate pathogenic mutations in the SPR gene, allowing for a definitive diagnosis...

Folic acid (FA) is easily photodegraded to yield 6-formylpterin and pterin-6-carboxylic acid, which can generate reactive oxygen species and result in the formation of oxidized guanine derivatives such as 8-hydroxy-2'-deoxyguanosine and 8-hydroxy-guanosine. In this study, we developed a simple, rapid, and sensitive liquid chromatography-tandem mass spectrometry strategy for the simultaneous determination of FA photolysis products and oxidized guanine derivatives in plasma samples. Chromatographic separation was performed on a Waters HSS T3 column (2...

In insects, different pigments, such as melanins and pterins, are involved in thermoregulation. The degree of melanisation often varies along geographical gradients, according to the so-called thermal melanism hypothesis, i.e. darker forms are found in colder places because they can warm up more quickly. Similarly, pterins work as heat sinks and thus are expected to be more abundant in colder sites. Cities, which are warmer than surrounding areas (Urban Heat Island (UHI) effect), might also be expected to influence pigmentation, although studies are lacking...

Hydroxylated aromatic compounds exhibit exceptional biological activities. In the biosynthesis of these compounds, three types of hydroxylases are commonly employed: cytochrome P450 (CYP450), pterin-dependent monooxygenase (PDM), and flavin-dependent monooxygenase (FDM). Among these, FDM is a preferred choice due to its small molecular weight, stable expression in both prokaryotic and eukaryotic fermentation systems, and a relatively high concentration of necessary cofactors. However, the catalytic efficiency of many FDMs falls short of meeting the demands of large-scale production...

Specific staining of cancer cells is momentous for cancer research. Nanoprobe with multivalent recognition is emerging as powerful tools for bioimaging, but the nonspecific cell uptake and complex functional modification procedures are still obstacles for specific detection and convenient synthesis. Carbon dots (CDs) with an intrinsic targeting ability, excellent optical properties and biocompatibility acquired from an efficient one-step fabrication procedure were urgently desired in specific cancer cells visualization...

Triphenyltin (TPT) is a typical persistent organic pollutant whose occurrence in coral reef ecosystems may threaten the survival of reef fishes. In this study, a brightly colored representative reef fish, Amphiprion ocellaris was used to explore the effects of TPT at environmental levels (1, 10, and 100 ng/L) on skin pigment synthesis. After the fish were exposed to TPT for 60 days, the skin became darker, owing to an increase in the relative area of black stripes, a decrease in orange color values while an increase in brown color values, and an increase in the number of melanocytes in the orange part of the skin tissues...

AIM: Type 1 diabetes (T1D) and its complications are known to be associated with oxidative stress. Pteridine derivatives and indoleamine 2,3-dioxygenase (IDO) activity can be used as biomarkers in the evaluation of oxidative stress. In this study, our aim is to compare the concentrations of serum and urinary pteridine derivatives, as well as serum IDO activity, in children and adolescents diagnosed with T1D and those in a healthy control group. METHOD: A cross-sectional study was performed and included 93 patients with T1D and 71 healthy children...

Escaping from danger is one of the most ndamental survival behaviors for animals. Most freshwater fishes display olfactory alarm reactions in which an injured fish releases putative alarm substances from the skin to notify its shoaling company about the presence of danger. Here, we identified two small compounds in zebrafish skin extract, designated as ostariopterin and daniol sulfate. Ostariopterin is a pterin derivative commonly produced in many freshwater fishes belonging to the Ostariophysi superorder. Daniol sulfate is a novel sulfated bile alcohol specifically present in the Danio species, including zebrafish...

In our efforts to develop inhibitors selective for neuronal nitric oxide synthase (nNOS) over endothelial nitric oxide synthase (eNOS), we found that nNOS can undergo conformational changes in response to inhibitor binding that does not readily occur in eNOS. One change involves movement of a conserved tyrosine, which hydrogen bonds to one of the heme propionates, but in the presence of an inhibitor, changes conformation, enabling part of the inhibitor to hydrogen bond with the heme propionate. This movement does not occur as readily in eNOS and may account for the reason why these inhibitors bind more tightly to nNOS...

The transition from inorganic catalysis through minerals to organic catalysis by enzymes is a necessary step in the emergence of life. Our work is elucidating likely reactions at the earliest moments of Life, prior to the existence of enzymatic catalysis, by exploring essential intersections between nickel bioinorganic chemistry and pterin biochemistry. We used a prebiotically-inspired acetylene-containing volcanic hydrothermal experimental environment to shed light on the efficient formation of nickel-organo complexes...

Folate was enriched during quinoa germination, while molecular mechanisms were not well understood. In this study, three quinoa varieties were selected for germination, and changes in substrate content and enzyme activity of the folate biosynthesis pathway were monitored. 5-Methyltetrahydrofolate (5-CH3 -THF) and 5-formyltetrahydrofolate (5-CHO-THF) were significantly enriched in quinoa sprouts. Among the selected varieties, QL-2 exhibited the lowest content of the oxidation product MeFox and the highest total folate content...

Metal-dependent, nicotine adenine dinucleotide (NAD+ )-dependent formate dehydrogenases (FDHs) are complex metalloenzymes coupling biochemical transformations through intricate electron transfer pathways. Rhodobacter capsulatus FDH is a model enzyme for understanding coupled catalysis, in that reversible CO2 reduction and formate oxidation are linked to a flavin mononuclotide (FMN)-bound diaphorase module via seven iron-sulfur (FeS) clusters as a dimer of heterotetramers. Catalysis occurs at a bis-metal-binding pterin (Mo) binding two molybdopterin guanine dinucleotides (bis-MGD), a protein-based Cys residue and a participatory sulfido ligand...

Angiogenesis is a key process in embryonic development, a disruption of this process can lead to severe developmental defects, such as limb malformations. The identification of molecular perturbations representative of antiangiogenesis in zebrafish embryo (ZFE) may guide the assessment of developmental toxicity from an endpoint- to a mechanism-based approach, thereby improving the extrapolation of findings to humans. Thus, the aim of the study was to discover molecular changes characteristic of antiangiogenesis and developmental toxicity...

Resveratrol (3,5,4'-trihydroxystilbene) is a natural stilbene synthetized as trans-isomer in plants exposed to oxidative stress. In order to understand the mechanism involved during photosensitized degradation of trans-resveratrol, steady-state and time-resolved experiments were performed and compared with quantum-chemical calculations using density functional theory (DFT). Pterin (Ptr), a well-known photosensitizer, under UV-A radiation induces the oxidation of several biomolecules mainly through electron-transfer mechanisms...

Efficiently expanding Chinese hamster ovary (CHO) cells, which serve as the primary host cells for recombinant protein production, have gained increasing industrial significance. A significant hurdle in stable cell line development is the low efficiency of the target gene integrated into the host genome, implying the necessity for an effective screening and selection procedure to separate these stable cells. In this study, the genes of phenylalanine hydroxylase (PAH) and pterin 4 alpha carbinolamine dehydratase 1 (PCBD1), which are key enzymes in the tyrosine synthesis pathway, were utilized as selection markers and transduced into host cells together with the target genes...

We report on interactions of different types of DNA molecules including double-stranded and plasmid DNA as well as polynucleotides (poly[dGdC]2 and poly[dAdT]2 ) with fac-[ReI (CO)3 (pterin)(H2 O)] (or Reptr) complex. The interaction was characterized spectroscopically and changes in the plasmid structure were verified by both electrophoresis and AFM microscopy. For comparative reasons, two others related tricarbonyl rhenium(I) complexes, fac-[(4,4'-bpy)ReI (CO)3 (dppz)]+ (or Redppz) and fac-[(CF3 SO3 )ReI (CO)3 (2,2'-bpy)] (or Rebpy) were also studied to further explore the influence of the different co-ligands on the interaction and DNA (photo)damage...

The authors describe a female in her late twenties, presenting with catatonia and diagnosed with epilepsy, autism spectrum disorder, mild intellectual disability, psychosis, dysthymia, anxiety and bipolar disorder, receiving weekly electroconvulsive therapy (ECT). After testing, findings indicated an interstitial deletion in the 22q13.33 region associated with Phelan-McDermid syndrome. In addition, the patient had low cerebral spinal fluid tetrahydrobiopterin (BH4 ) levels, suggesting dysfunction in the pterin biosynthetic pathway...

UNLABELLED: Biofilm formation and surface attachment in multiple Alphaproteobacteria is driven by unipolar polysaccharide (UPP) adhesins. The pathogen Agrobacterium tumefaciens produces a UPP adhesin, which is regulated by the intracellular second messenger cyclic diguanylate monophosphate (cdGMP). Prior studies revealed that DcpA, a diguanylate cyclase-phosphodiesterase (DGC-PDE), is crucial in control of UPP production and surface attachment. DcpA is regulated by PruR, a protein with distant similarity to enzymatic domains known to coordinate the molybdopterin cofactor (MoCo)...

The anaerobic region of the gastrointestinal (GI) tract has been replicated in the anaerobic chamber of a microbial fuel cell (MFC). Electroactive biomolecules released by the facultative anaerobes (Providencia rettgeri) under anoxic conditions have been studied for their potential role for redox balance. MALDI study reveals the presence of vitamin B9 (folate), 6-methylpterin, para-aminobenzoic acid (PABA) and pteroic acid called pterin pool. ATR-FTIR studies further confirm the presence of the aromatic ring and side chains of folate, 6-methylpterin and PABA groups...