guanosine-triphosphate and triphosphoric-acid

It has recently become evident that the bacterial stringent response is regulated by a triphosphate alarmone (pGpp) as well as the canonical tetra- and pentaphosphate alarmones ppGpp and pppGpp [together, (p)ppGpp]. Often dismissed in the past as an artifact or degradation product, pGpp has been confirmed as a deliberate endpoint of multiple synthetic pathways utilizing GMP, (p)ppGpp, or GDP/GTP as precursors. Some early studies concluded that pGpp functionally mimics (p)ppGpp and that its biological role is to make alarmone metabolism less dependent on the guanine energy charge of the cell by allowing GMP-dependent synthesis to continue when GDP/GTP has been depleted. However, recent reports that pGpp binds unique potential protein receptors and is the only alarmone synthesized by the intestinal pathogen Clostridioides difficile indicate that pGpp is more than a stand-in for the longer alarmones and plays a distinct biological role beyond its functional overlap (p)ppGpp.

Topics: Bacterial Proteins; Guanosine Pentaphosphate; Guanosine Tetraphosphate; Guanosine Triphosphate; Nucleotides

This unit describes a facile, reliable, and efficient method for the gram-scale chemical synthesis of unlocked nucleic acid- (UNA) nucleoside-5'-O-triphosphates such as UNA-guanosine-5'-O-triphosphate (UNA-GTP), UNA-adenosine-5'-O-triphosphate (UNA-ATP), UNA-cytidine-5'-O-triphosphate (UNA-CTP), and UNA-uridine-5'-O-triphosphate (UNA-UTP), starting from the commercially available corresponding nucleoside-5'-O-triphosphate. The present process involves a "one-pot, two-step" strategy that utilizes green chemistry principles. The overall reaction involves the oxidation of nucleoside-5'-O-triphosphate using sodium periodate under aqueous conditions, followed by reduction using sodium borohydride to furnish the corresponding UNA-nucleoside-5'-O-triphosphate in good yields with high purity (>99.5%). © 2023 Wiley Periodicals LLC. Basic Protocol: Synthesis of UNA-nucleoside-5'-O-triphosphates.

Topics: Adenosine Triphosphate; Guanosine Triphosphate; Nucleic Acids; Nucleosides; Nucleotides

Adenosine 5'-triphosphate (ATP) and guanosine 5'-triphosphate (GTP) are the most essential energy source in enormous biological processes. Various probes for ATP or GTP sensing, have been widely established, but the probe that could simultaneously monitor ATP and GTP is still rarely reported. Herein, we report a bipolar hemicyanine cationic probe for simultaneous sensing of ATP and GTP via a one-step monitoring process. This probe exhibited strong affinity to ATP and GTP through intramolecular electrostatic and π-π stacking interactions, which the binding constant on each step were determined as 6.15 × 10

Topics: Adenosine; Adenosine Triphosphate; Guanosine Diphosphate; Guanosine Triphosphate

Leishmania virulence proteins should be considered as vaccine candidates against disease, since they are involved in developing infection in mammalian hosts. In a previous study, a Leishmania guanosine-5'-triphosphate (GTP)-binding protein was identified as a potential parasite virulence factor. In the present work, the gene encoding GTP was cloned and the recombinant protein (rGTP) was evaluated as a vaccine candidate against Leishmania infantum infection. The protein was associated with saponin (rGTP/Sap) or Poloxamer 407-based micelles (rGTP/Mic) as adjuvants, and protective efficacy was investigated in BALB/c mice after parasite challenge. Both rGTP/Sap and rGTP/Mic compositions induced a Th1-type immune response in vaccinated animals, with significantly higher levels of IFN-γ, IL-12, IL-2, TNF-α, GM-CSF, nitrite, specific IgG2a isotype antibody and positive lymphoproliferation, when compared to the control groups. This response was accompanied by significantly lower parasite load in the spleens, livers, bone marrows and draining lymph nodes of the animals. Immunological and parasitological evaluations indicated that rGTP/Mic induced a more polarized Th1-type response and higher reduction in the organ parasitism, and with lower hepatotoxicity, when compared to the use of rGTP/Sap. In conclusion, our preliminary data suggest that rGTP could be considered for further development as a vaccine candidate to protect against VL.

Topics: Animals; Antigens, Protozoan; Carrier Proteins; Guanosine; Guanosine Triphosphate; Leishmania infantum; Leishmaniasis; Leishmaniasis, Visceral; Mammals; Mice; Mice, Inbred BALB C; Micelles; Poloxamer; Polyphosphates; Recombinant Proteins

Imidazole-based metal-organic frameworks (MOFs) are easy to prepare as well-dispersed nanoparticles, which have attracted a lot of interest in sensing. Metal substitution is an effective way to regulate the composition and performance of MOFs. Herein, by tuning the contents of Co and Zn, a series of homobimetallic Co

Topics: Adenosine Triphosphate; Coloring Agents; DNA; Guanosine Triphosphate; Metal-Organic Frameworks; Nucleosides; Polyphosphates; Zeolites

Topics: Animals; Calcium; CD18 Antigens; Cell Adhesion; Guanosine; Guanosine Triphosphate; Humans; Interleukin-8; Mice; Mice, Inbred C57BL; Neutrophils; Polyphosphates; rac1 GTP-Binding Protein

Guanosine-5'-triphosphate (GTP) plays a key role in many important biological processes of cells. It is not only a primer for DNA replication and one of the four essential nucleoside triphosphates for mRNA synthesis, but also an energy source for translation and other important cellular processes. It can be converted to adenine nucleoside triphosphate (ATP), and the intracellular GTP level is closely related to the specific pathological state, so it is crucial to establish a simple and accurate method for the detection of GTP. Deoxyribozymes have unique catalytic and structural properties. One of the deoxyribozymes which is named DK2 with self-phosphorylation ability can transfer a phosphate from GTP to the 5' end in the presence of manganese(ii), while lambda exonuclease (λexo) catalyzes the gradual hydrolysis of double-stranded DNA molecules phosphorylated at the 5'-end from 5' to 3', but cannot cleave the 5'-OH end. The fluorescent dye SYBR Green I (SG I) can bind to dsDNA and produce significant fluorescence, but it can only give out weak fluorescence when it is mixed with a single strand. Here, we present a novel unlabeled fluorescence assay for GTP based on the self-phosphorylation of deoxyribozyme DK2 and the specific hydrolysis of λexo. Owing to the advantages of simple operation, high sensitivity, good specificity, low cost and without fluorophore (quenching group) labeling, this method has great potential in biological applications.

Topics: DNA, Catalytic; Fluorescent Dyes; Guanosine; Guanosine Triphosphate; Polyphosphates

Human ribonucleotide reductases (hRNRs) catalyze the conversion of nucleotides to deoxynucleotides and are composed of α- and β-subunits that form active α(n)β(m) (n, m = 2 or 6) complexes. α binds NDP substrates (CDP, UDP, ADP, and GDP, C site) as well as ATP and dNTPs (dATP, dGTP, TTP) allosteric effectors that control enzyme activity (A site) and substrate specificity (S site). Clofarabine (ClF), an adenosine analog, is used in the treatment of refractory leukemias. Its mode of cytotoxicity is thought to be associated in part with the triphosphate functioning as an allosteric inhibitor of hRNR. Studies on the mechanism of inhibition of hRNR by ClF di- and triphosphates (ClFDP and ClFTP) are presented. ClFTP is a reversible inhibitor (K(i) = 40 nM) that rapidly inactivates hRNR. However, with time, 50% of the activity is recovered. D57N-α, a mutant with an altered A site, prevents inhibition by ClFTP, suggesting its A site binding. ClFDP is a slow-binding, reversible inhibitor ( K(i)*; t(1/2) = 23 min). CDP protects α from its inhibition. The altered off-rate of ClFDP from E•ClFDP* by ClFTP (A site) or dGTP (S site) and its inhibition of D57N-α together implicate its C site binding. Size exclusion chromatography of hRNR or α alone with ClFDP or ClFTP, ± ATP or dGTP, reveals in each case that α forms a kinetically stable hexameric state. This is the first example of hexamerization of α induced by an NDP analog that reversibly binds at the active site.

Topics: Adenine Nucleotides; Adenosine Triphosphate; Algorithms; Allosteric Regulation; Antineoplastic Agents; Arabinonucleosides; Binding Sites; Biocatalysis; Catalytic Domain; Clofarabine; Diphosphates; Guanosine Triphosphate; Humans; Kinetics; Molecular Structure; Mutation; Polyphosphates; Protein Multimerization; Protein Structure, Quaternary; Protein Subunits; Ribonucleotide Reductases; Substrate Specificity; Time Factors

A molecular dynamics DFT:B3LYP (6-31G(**) basis set) study is used to elucidate the mechanism of guanosinetriphosphate (GTP) conversion into guanosinemonophosphate (GMP) upon the action of Mg(2+) (magnesium cofactor). The computations are carried out at 310 K in a volume of 178 water molecules, which surround the Mg(2+)-GTP complex and imitate the effect of solution. Over 5 ps, Mg(2+)-GTP appears to be fully decomposed, yielding five final products: two hydrated molecules of inorganic phosphate Pi, a hydrated Mg(2+), atomic oxygen (which in the course of a couple of subsequent reactions gains two hydrogens and converts into a water molecule) and a highly active *GMP radical. The radical production is linked to presence of Mg(2+), which initiates a radical mechanism of GTP cleavage. At the initial stage, Mg(2+) undergoes reduction to Mg(+), accompanied by the formation of an ion-radical pair with GTP, (+)Mg*-*GTP(3-). Without Mg(2+), an inert form of GMP (the ionic mechanism of GTP hydrolytic cleavage) rather than GMP is produced. *GMP production, which is similar to that of *AMP (adenosinemonophosphate), *CMP (cytidinemonophosphate), TMP (thymidinemonophosphate) and *UMP (uridinemonophosphate), plays a crucial role in DNA and RNA single chain synthesis.

Topics: Chelating Agents; DNA; Guanosine Monophosphate; Guanosine Triphosphate; Hydrolysis; Magnesium; Models, Chemical; Molecular Conformation; Oxygen; Phosphates; Polyphosphates; Pyrimidine Nucleotides; RNA

After the removal of the exchangeable guanine nucleotides by chromatography on phenyl-Sepharose [Hanssens, I., Baert, J., and Van Cauwelaert, F. (1990) Biochemistry 29, 5160-5165] tubulin polymerizations with GTP, GDP, tripolyphosphate, pyrophosphate or orthophosphate as possible stimulants are compared. It is demonstrated that, besides GTP and pyrophosphate, also tripolyphosphate stimulates the assembly into microtubules at high concentrations (4.65 mM) of Mg2+. The influence of Mg2+ is more pronounced in combination with pyrophosphate and tripolyphosphate than with GTP. The microtubules assembled in combination with Mg2+ and tripolyphosphate or pyrophosphate are short, suggesting that especially the nucleation step of microtubule assembly is favoured.

Topics: Animals; Brain Chemistry; Diphosphates; Guanine Nucleotides; Guanosine Diphosphate; Guanosine Triphosphate; Magnesium; Microscopy, Electron; Microtubules; Negative Staining; Phosphates; Polyphosphates; Swine; Tubulin

ATP has been reported to affect glucose transport in human erythrocytes and resealed erythrocyte ghosts [Jacquez, J. A. (1983) Biochim. Biophys. Acta 727, 367-378; Jensen, M. R., & Brahm, J. (1987) Biochim. Biophys. Acta 900, 282-290]. In more detailed studies, effects of micromolar levels of ATP on transport in ghosts and inside-out vesicles, and on the fluorescence of ghosts and the purified glucose transporter [Carruthers, A. (1986) Biochemistry 25, 3592-3602; Hebert, D. N., & Carruthers, A. (1986) J. Biol. Chem. 261, 10093-10099; Carruthers, A. (1986) J. Biol. Chem. 261, 11028-11037], have been interpreted as supporting a model in which ATP regulates the catalytic properties of the transporter. Both allosteric and covalent effects of ATP were proposed; among the allosteric effects was a 60% reduction in the Km for zero-trans uptake. In order to test whether allosteric ATP regulation of the transporter occurs, we reconstituted glucose transport activity into liposomes using erythrocyte membranes without detergent treatment. The effects of ATP, present either outside, inside, or both inside and outside the liposomes, on the transport activity were examined. Effects of ATP on trypsin-treated liposomes, which have only a single orientation of active transporters, were also tested. While the model predicts activation by ATP, only inhibition was observed. This was significant only at millimolar concentrations of ATP, in contrast to the previously reported effects at micromolar levels, and was primarily on the extracellular surface of the transporter. In addition, the ATP effects on reconstituted transport were nonspecific, with similar effects produced by tripolyphosphate.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adenosine Triphosphate; Biological Transport, Active; Calcium; Erythrocyte Membrane; Glucose; Guanosine Triphosphate; Humans; In Vitro Techniques; Kinetics; Liposomes; Magnesium; Monosaccharide Transport Proteins; Polyphosphates

Topics: Amino Acids; Antifibrinolytic Agents; Biochemical Phenomena; Guanosine Triphosphate; Nucleoproteins; Nucleosides; Nucleotides; Polyphosphates; Ribosomal Proteins; RNA