Tris 3-phosphate

Basically, AZT is anabohcaHy phosphorylated to AZT mono-, di-, and tri-phosphates by various enzymes (kinases) of a target ceU (159). AZT-triphosphate competes with other phosphorylated pyrimidine nucleosides for incorporation into HIV DNA by the viral reverse transcriptase. Incorporation of the AZT-triphosphate into reverse transcriptase results in viral DNA chain termination. Reverse transcriptase is essential in the repHcative cycle of HIV. 

Analogues of Dinucleoside Di(Tri)phosphates and Oligonucleotides with a Di(Tri)phosphate Bridge... 

A 1,5-hour inhalation exposure of mixed breed rabbits to airborne concentrations of 72 ppm of hydrogen sulfide resulted in ventricular repolarization, while a 5-day, 0.5-hour/day exposure to this concentration resulted in cardiac arrhythmia (Kosmider et al. 1967). Histochemical staining of the myocardial cells revealed a reduction in adenosine tri-phosphate (ATP) phosphohydrolase and NADPH2 oxidoreductase (Kosmider et al. 1967). Cardiac arrhythmia, suggestive of a stimulus transmission disorder, was... 

The binding of the sperm to a receptor on the membrane of the oocyte either activates a membrane-bound phospholipase or releases a phospholipase into the oocyte. The phospholipase hydrolyses phosphatidylinositol bisphos-phate to produce the two intracellular signals, inositol tris-phosphate (IP3) and diacylglycerol within the ovum. As in other cells, the IP3 signal increases the level of cytosolic Ca + ions and the diacylglycerol (DAG) signal activates protein kinase C. 

Smooth muscle effects. The opposing effects on smooth muscle (A) of a-and p-adrenoceptor activation are due to differences in signal transduction (p. 66). This is exemplified by vascular smooth muscle (A). ai-Receptor stimulation leads to intracellular release of Ca + via activation of the inositol tris-phosphate (IP3) pathway. In concert with the protein calmodulin, Ca + can activate myosin kinase, leading to a rise in tonus via phosphorylation of the contractile protein myosin. cAMP inhibits activation of myosin kinase. Via the former effector pathway, stimulation of a-receptors results in vasoconstriction via the latter, P2-receptors mediate vasodilation, particularly in skeletal muscle - an effect that has little therapeutic use. 

This enzyme [EC 3.1.3.25], also referred to as myo-inosi-tol-l(or 4)-monophosphatase and myo-inositol-l-phos-phatase, catalyzes the hydrolysis of myo-inositol 1-monophosphate to generate myo-inositol and orthophosphate. Both enantiomers of myo-inositol 1-phosphate and myoinositol 4-phosphate can act as substrates. However, the enzyme does not hydrolyze inositol bisphosphates, tris-phosphates, or tetrakisphosphates. 

This enzyme [EC 2.7.1.40] catalyzes the reaction of ADP with phosphoenolypyruvate to produce ATP and pyruvate. Other nucleotides that can be used as substrates include UDP, GDP, CDP, IDP, and dADP. The enzyme will also phosphorylate hydroxylamine and fluoride in the presence of carbon dioxide. See Nucleoside 5 -Tri-phosphate Regeneration... 

Immunocytochemical Labeling. Antibodies were used as post-embedding markers. Sections of decayed wood were first incubated on a drop of TBS (Tris-phosphate saline buffer 0.1 M, pH 7.4, NaCl 0.15 M or 0.5 M), glycine... 

The oxidation of 1,2- and 1,4-dihydropyridines has been extensively studied. This is due in large part to the occurrence of the 1,4-dihydropyridine ring system in the reduced forms of the coenzymes nicotinamide adenine di- and tri-phosphate (NADH and NADPH). These redox couples are responsible for a number of biological oxidations and reductions (B-70MI20701). 

The tetraphosphate anion is practically stable in neutral and alkaline solution at room temperature but at 65.9°C it is about half a power of ten less stable than the triphosphate anion over the whole pH range (61). Tetraphosphate has its maximum stability at 65.5°C at pH 10 and this is why it can be prepared from tetrametaphosphate at such temperatures. Its stability becomes smaller with decreasing pH. Apparently during the hydrolysis of an aqueous solution, which follows a first order law at constant pH, the tetraphosphate is cleaved initially exclusively at the end of the chain, to form mono- and tri-phosphate. 

In more complex flow-injection systems the organophosphorus samples are injected without previous mineralization, and all decomposition reactions are carried out in the instrument itself oxidation of organic compounds by digestion with, for instance, per-oxodisulphate in a heated capillary tube18,19 or hydrolysis of di- and tri-phosphates with... 

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