Adenosine diphosphate and adenosine monophosphate: enzymatic spectrophotometric determination

1990 ◽  
Vol 1 (8) ◽  
pp. 440-444 ◽  
Author(s):  
K Tornheim
Keyword(s):  
Spectrophotometric Determination ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate

Selective sensing of adenosine monophosphate (AMP) over adenosine diphosphate (ADP), adenosine triphosphate (ATP), and inorganic phosphates with zinc(II)-dipicolylamine-containing gold nanoparticles

2021 ◽  
Author(s):  
Lena Reinke ◽  
Marcus Koch ◽  
Christine Müller-Renno ◽  
Stefan Kubik
Keyword(s):  
Gold Nanoparticles ◽  
Adenosine Triphosphate ◽  
Triethylene Glycol ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
Mixed Monolayer ◽  
Inorganic Phosphates

Mixed monolayer-protected gold nanoparticles containing surface-bound triethylene glycol and dipicolylamine groups aggregated in water/methanol, 1:2 (v/v) in the presence of nucleotides, if the solution also contained zinc(II) nitrate to convert...

scholarly journals ON THE LOCALIZATION OF SOME PHOSPHATASES IN THREE DIFFERENT SEGMENTS OF THE PROXIMAL TUBULES IN THE RAT KIDNEY

1967 ◽  
Vol 15 (8) ◽  
pp. 456-469 ◽  
Author(s):  
N. O. JACOBSEN ◽  
F. JØRGENSEN ◽  
Å. C. THOMSEN
Keyword(s):  
Adenosine Triphosphate ◽  
Rat Kidney ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
Proximal Tubules ◽  
Reaction Pattern ◽  
Cytoplasmic Bodies ◽  
Acid And Alkaline Phosphatase ◽  
Convoluted Tubules

The distribution of several phosphatases in three segments of the proximal tubules was studied in frozen sections of glutaraldehyde-fixed rat kidneys. Two segments of the convoluted tubules were identified by in vivo injection of trypan blue. By increasing the concentration of adenosine triphosphate to 3 mM in the Wachstein and Meisel ATPase medium, a clear segmental differentiation in the reaction pattern of the brush border, cytoplasmic bodies and basal infoldings of the proximal tubules was obtained. The specificity of the reaction was investigated by substituting adenosine diphosphate, adenosine monophosphate or β-glycerophosphate for adenosine triphosphate in the incubation medium and by employing cyanide or fluoride as inhibitors. The reaction pattern was also compared with the localization of acid and alkaline phosphatase activities. In addition, the distribution of glucose 6-phosphatase activity was studied which showed differences in the three segments of the proximal tubules.

Isolated flagellar apparatus of Chlamydomonas: characterization of forward swimming and alteration of waveform and reversal of motion by calcium ions in vitro

1978 ◽  
Vol 33 (1) ◽  
pp. 235-253 ◽  
Author(s):  
J.S. Hyams ◽  
G.G. Borisy
Keyword(s):  
Calcium Ions ◽  
Beat Frequency ◽  
Flagellar Apparatus ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
Living Cells ◽  
Exogenous Calcium ◽  
Ph Range ◽  
Relationship Of

The control of flagellar activity in the biflagellate green alga, Chlamydomonas reinhardtii was investigated by the in vitro reactivation of the isolated flagellar apparatus (the 2 flagella attached to their respective basal bodies plus accessory structures). The waveform and beat frequency of the isolated apparatus in the presence of 1 mM adenosine triphophate (ATP) were comparable to those recorded for living cells. Equimolar concentrations of adenosine diphosphate (ADP) could be substituted for ATP with little change in beat frequency and no apparent change in waveform, suggesting that the latter is converted to ATP by axonemal adenylate kinase. No reactivation occurred in adenosine monophosphate (AMP). But frequencies in cytidine, guanosine and uridine triphosphates (CTP, GTP and UTP) were approximately 10% that obtained in ATP. Reactivation was optimal over a broad pH range between pH 6.4 and pH 8.9 in both APT and ADP. Isolated flagellar apparatus could be induced to change from forward to reverse motion in vitro by manipulation of exogenous calcium ions. The 2 types of motion were directly comparable to recorded responses of living cells. Forward swimming occurred at levels of calcium below 10(−6)M, the isolated apparatus changing to backward motion above this level. Motility was inhibited at concentrations above 10(−3)M. The threshold for reversal of motion by calcium was lowered to 10(−7)M when the flagellar membranes were solubilized with detergent, indicating that the flagellar membranes are involved in the regulaion of the level of calcium within the axoneme. The reversal of motion by calcium was itself freely reversible. The relationship of these observations to the known tactic responses of Chlamydomonas is discussed.

scholarly journals Crowding within synaptic junctions influence the degradation of adenoside nucleotides by CD39 and CD73 ectonucleotidases

2021 ◽  
Author(s):  
Hadi Rahmaninejad ◽  
Tom Pace ◽  
Peter Kekenes-Huskey
Keyword(s):  
Electrostatic Interactions ◽  
Configurational Entropy ◽  
Reaction Diffusion ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
Surprising Result ◽  
Surface Charges ◽  
Association Rate ◽  
Synaptic Junction ◽  
Reaction Diffusion Model

Synapsed cells can communicate using exocytosed nucleotides like adenosine triphosphate (ATP). Ectonucleotidases localized to a synaptic junction degradesuch nucleotides into metabolites like adenosine monophosphate (AMP) or adenosine, oftentimes in a sequential manner. CD39 and CD73 are a representativeset of coupled ectonucleotidases, where CD39 first converts ATP and adenosine diphosphate (ADP) into AMP, after which the AMP product is dephosphorylated into adenosine by CD73. Hence, CD39/CD73 help shape cellular responses to extracellular ATP. In a previous study [1] we demonstrated that the rates of coupled CD39/CD73 activity within synapse-like junctions are strongly controlled by the enzymes' co-localization, their surface charge densities, and the electrostatic potential of the surrounding cell membranes. In this study, we demonstrate that crowders within a synaptic junction, which can include globular proteins like cytokines and membrane-bound proteins, impact coupled CD39/CD73 electronucleotidase activity and in turn, the availability of intrasynapse ATP. Specifically, we simulated a spatially-explicit, reaction-diffusion model for the coupled conversion of ATP -> AMP and AMP -> adenosine in a model synaptic junction with crowders via the finite element method. Our modeling results suggest that the association rate for ATP to CD39 is strongly influenced by the density of intrasynaptic protein crowders, as increasing crowder density suppressed ATP association kinetics. Much of this suppression can be rationalized based on a loss of configurational entropy. The surface charges of crowders can further influence the association rate, with the surprising result that favorable crowder/nucleotide electrostatic interactions can yield CD39 association rates that are faster than crowder-free configurations. However, attractive crowder/nucleotide interactions decrease the rate and efficiency of adenosine production, which in turn increases the availability of ATP and AMP within the synapse relative to crowder-free configurations. These findings highlight how CD39/CD73 ectonucleotidase activity, electrostatics and crowding within synapses influence the availability of nucleotides for intercellular communication.

scholarly journals Studies on Human Erythrocyte Nucleotide Metabolism. II. Nonspherocytic Hemolytic Anemia, High Red Cell ATP, and Ribosephosphate Pyrophosphokinase (RPK, E.C. 2.7.6.1) Deficiency

Blood ◽  
1972 ◽  
Vol 39 (5) ◽  
pp. 674-684 ◽  
Author(s):  
William N. Valentine ◽  
Helen M. Anderson ◽  
Donald E. Paglia ◽  
Ernst R. Jaffé ◽  
Patricia N. Konrad ◽  
...  
Keyword(s):  
Hemolytic Anemia ◽  
Reduced Glutathione ◽  
Adenine Nucleotides ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
Blood Film ◽  
Nucleotide Metabolism ◽  
Glutathione Metabolism ◽  
Final Decision ◽  
Blood Samples

Abstract A 29-yr-old black woman was found to have a long-standing, nonspherocytic hemolytic disorder associated with a marked reduction in the activity of erythrocyte ribosephosphate pyrophosphokinase (RPK, PRPP synthetase, E.C. 2.7.6.1). Although the patient’s erythrocytes had about 50% of the average RPK activity of normal mature human erythrocytes, this level represented only about 20-30% of the activity in comparable reticulocyte-rich blood samples from patients with other types of hemolytic anemias. The concentrations of adenosine triphosphate adenosine diphosphate, adenosine monophosphate and, therefore, of total adenine nucleotides in her erythrocytes were markedly increased, even well above the levels in extracts of comparable reticulocyte-rich blood samples. ATPase activity was increased three- to fourfold, consistent with the reticulocytosis. Adenylate kinase and adenine phosphoribosyltransferase activities were normal. The activities of all enzymes of the Embden-Meyerhof and hexose monophosphate shunt pathways and enzymes related to glutathione metabolism were normal or increased, consistent with the reticulocytosis. The concentrations of glycolytic intermediates, other than adenine nucleotides, were normal. The conversion of glucose, adenosine, and inosine to lactate was normal or increased. Autohemolysis was of the Dacie Type II. The concentrations of erythrocyte-reduced glutathione were high normal or elevated. The stained blood film showed a striking degree of basophilic stippling of the erythrocytes. Studies of the erythrocytes of the patient’s only known relative, a son, have failed to reveal any hematologic or enzymatic abnormalities. A direct causal relationship between RPK deficiency, high ATP concentrations, and nonspherocytic hemolytic anemia could not be derived from data now available. The final decision as to whether the deficiency is primary and causative or is an epiphenomenon requires investigation of additional cases.

scholarly journals Effect of hypoxia on purine metabolism of human skeletal muscle cells

Biotecnia ◽  
2021 ◽  
Vol 23 (2) ◽  
Author(s):  
Tania Zenteno-Savín ◽  
Crisalejandra Rivera-Pérez ◽  
Ramón Gaxiola-Robles ◽  
Norma Olguín-Monroy ◽  
Orlando Lugo-Lugo ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
De Novo ◽  
Muscle Cells ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
Purine Metabolism ◽  
Inosine Monophosphate Dehydrogenase ◽  
Inosine Monophosphate ◽  
Hypoxic Conditions ◽  
Human Skeletal Muscle Cells

Mammals experience some degree of hypoxia during their lifetime. In response to hypoxic challenge, mammalian cells orchestrate specific responses at transcriptional and posttranslational level which lead to changes in the purine metabolites in order to cope with threatening conditions. The aim of this study was to evaluate the response of the enzymes involved in the purine metabolism of human muscle cells to hypoxic conditions. Muscle cells in culture were exposed to hypoxia and the enzymatic activity of inosine monophosphate dehydrogenase (IMPDH), xanthine oxidase (XO), purine nucleoside phosphorylase (PNP) and hypoxanthine guanine phosphoribosyl transferase (HGPRT) as well as their transcript expression were quantified under normoxic and hypoxic conditions. Purine metabolite (hypoxanthine (HX), xanthine (X), uric acid (UA), inosine monophosphate (IMP), inosine, nicotinamide adenine dinucleotide (NAD+), adenosine, adenosine monophosphate (AMP), adenosine diphosphate (ADP), adenosine triphosphate (ATP), guanosine diphosphate (GDP) and guanosine triphosphate (GTP)) concentrations were also quantified. Significant reduction of IMPDH activity and HX and IMP concentrations (p < 0.05) were observed after hypoxia, suggesting a decrease of de novo synthesis of purines. After hypoxia a global reduction of transcripts was observed, suggesting a reduction of the metabolic machinery of purine metabolism to new steady states that balance ATP demand and ATP supply pathways.

scholarly journals Zinc-induced platelet aggregation is mediated by the fibrinogen receptor and is not accompanied by release or by thromboxane synthesis

Blood ◽  
1985 ◽  
Vol 66 (1) ◽  
pp. 213-219 ◽  
Author(s):  
P Heyns A du ◽  
A Eldor ◽  
R Yarom ◽  
G Marx
Keyword(s):  
Platelet Aggregation ◽  
Dense Body ◽  
Platelet Rich Plasma ◽  
Adenosine Monophosphate ◽  
Adenosine Diphosphate ◽  
Creatine Phosphate ◽  
Calcium Flux ◽  
Fibrinogen Receptor ◽  
Induced Aggregation

Abstract We demonstrate that zinc (0.1 to 0.3 mmol/L) induces aggregation of washed platelet suspensions. Higher concentrations (1 to 3 mmol/L) of zinc were needed to aggregate platelets in platelet-rich plasma obtained from blood anticoagulated with low-molecular-weight heparin, probably due to the binding of zinc to the plasma proteins. Zinc- induced aggregation of normal washed platelets required added fibrinogen and no aggregation occurred with thrombasthenic platelets or with normal platelets pretreated with a monoclonal antibody (10E5) that blocks the platelet fibrinogen receptor. These data indicate that the platelet membrane fibrinogen receptor-glycoproteins IIb and IIIa mediate the effect of zinc. Zinc-induced aggregation was blocked by the agent TMB-8, which interferes with the internal calcium flux, and by prostacyclin, which elevates platelet cyclic adenosine monophosphate levels. Zinc-induced aggregation was not accompanied by thromboxane synthesis or by the secretion of dense-body serotonin and was not affected by preexposure of platelets to acetylsalicylic acid. Experiments with creatine phosphate/creatine phosphokinase showed that the zinc effect on platelets was independent of extracellular adenosine diphosphate (ADP). Zinc had an additive effect when platelet aggregation was stimulated with subthreshhold concentrations of collagen or ADP. Together with the known effects of nutritional zinc on in vivo bleeding, on platelet aggregation, and on lipid metabolism, the results suggest that zinc may have an important bearing on normal hemostasis, thrombosis, and atherosclerosis.

Characterization of the NTPDase activities in the mesentery pre- and post-capillary circuits of the guinea pig

2003 ◽  
Vol 81 (3) ◽  
pp. 212-219 ◽  
Author(s):  
M Duval ◽  
A R Beaudoin ◽  
G Bkaily ◽  
F P Gendron ◽  
P D'Orléans-Juste
Keyword(s):  
Guinea Pig ◽  
Specific Inhibitor ◽  
Adenosine Monophosphate ◽  
Complete Removal ◽  
Adenosine Diphosphate ◽  
Disulfonic Acid ◽  
Similar Response ◽  
Reaction Products ◽  
Nitric Oxide Synthase Inhibitor ◽  
Synthase Inhibitor

NTPDase is one of the principal enzymes involved in the sequential hydrolysis of ATP. In the present study, the presence and functionality of NTPDase in the mesenteric vein and artery were examined. Adenosine triphosphate (ATP) (0.01–1000 pmol) induces a dose-dependent vasodilation in the isolated arterial and venous mesenteric vasculatures of the guinea pig. Adenosine diphosphate (ADP) (0.01–1000 pmol) but not adenosine monophosphate (AMP) (0.01–1000 pmol) induces a similar response in the mesenteric vascular circuit. L-NAME, a nitric oxide synthase inhibitor (200 µM, 30 min), significantly reduces the arterial dilatory effect of ATP and abolishes the responses to ADP and AMP. Complete removal of the endothelium with 3-[(3-cholamidopropyl) dimethylammonio]-1-propansulfonate (CHAPS) (20 mM, 2 × 45 s) abolishes ATP-induced responses. Infusion of ATP in the vascular circuit generated detectable amounts of ADP and AMP, as measured by HPLC. CHAPS treatment significantly reduced the level of ATP and the production of AMP in the arterial mesenteric circuit. In contrast to the arterial mesenteric vasculature, endothelium removal in the venous circuit triggered a marked potentiation of ADP release and, interestingly, a marked reduction in the release of AMP. Moreover, a specific inhibitor of NTP diphosphohydrolase, 1-hydroxynaphthlene-3,6-disulfonic acid BGO 136 (10 mM for 20 min), significatively reduced AMP production in both vascular preparations. These results confirm that the endothelium contributes to the vasoactive properties of ATP, ADP, and AMP. Our data also demonstrated a significant role of endothelium in NTPDase activity on ADP and AMP production prior to exogenous administration of ATP. The activity of this particular enzyme appears to be different from the reaction products viewpoint (i.e., the production of ADP) in the pre- and post-mesenteric circuits, suggesting two different isoforms with different substrate specificities.Key words: ATP, ADP, AMP, NTPDase, mesenteric vasculature.

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