Diadenosine phosphates

N. V. C. Ralston, C. D. Hunt, Diadenosine phosphates and S-adenosylmethi-onine novel boron binding biomolecules detected by capillary electrophoresis, Biochimica Et Biophysica Acta - General Subjects 2001,1527, 20. 

A full equivalent of diadenosine phosphate was extracted into organic solvents per equivalent of 59a, indicating that the receptor has a very high affinity for the dinucleotide. NMR experiments established that the carbazole group tt-stacks with the heterocyclic base of the nucleotide, and the Kemp triacid does indeed hydrogen-bond with the receptor, which is therefore an efficient nucleotide transporter, as determined by U-tube experiments. In these transport measurements, 59c, which contains a 2-naphthoyl moiety, gave increased transport rates for adenosine monophosphate guests. 

Ap4A, diadenosine tetraphosphate BBG, Brilliant blue green BzATP, 2 - 3 -0-(4-benzoyl-benzoyl)-ATP cAMP, cyclic AMP CCPA, chlorocyclopentyl adenosine CPA, cyclopentyl adenosine CTP, cytosine triphosphate DPCPX, 8-cyclopentyl-1,3-dipnopylxanthine IP3, inosine triphosphate lpsl, diinosine penta phosphate a,p-meATP, a,p-methylene ATP p.y-meATP, p.y-meihylene ATP 2-MeSADP, 2-methylthio ADP 2-MeSAMP, 2-methylthio AMP 2-MeSATP, 2-methylthio ATP NECA, 5 -W-ethylcarboxamido adenosine PPADS, pyridoxal-phosphate-6-azophenyl-2, 4 -disulfonic acid PLC, phospholipase C RB2, reactive blue 2 TNP-ATP, 2, 3 -0-(2,4,6-trinitrophenyl) ATP. 

After these general comments let us further test the idea of thermodynamic buffering on an experimental basis by repeating the above experiment but this time in the presence of an inhibitor of adenylate kinase, namely, diadenosine pentaphosphate. As is depicted in Fig. 6b the buffering effect of the adenylate kinase is abolished by inhibiting this enzyme and it becomes now possible to drive the system beyond the state of optimal efficiency by increasing the hexokinase concentration in the medium. Note that it was not possible to measure points closer to level flow than the ones shown in the figure. This is due to technical reasons. At the lowest phosphate potentials the ATP/ADP ratios where of the order... 

Reagent layer Buffer. pH 70, creatine phosphate, ADP, magnesium acetate, diadenosine penta-phosphate, glycerol, peroxidase, glycerol kinase, leuco dye precursor, L-a-glycero-phosphate oxidase, AMP, creatine phosphate ... 

During the enzymic synthesis of carbamyl phosphate (34), two molecules of ATP are involved for every molecule of (34) that is synthesized. One molecule of ATP reacts with bicarbonate to form a mixed anhydride of orthophosphoric and carbonic acids, while the second molecule of ATP phosphorylates the carbamate once it is formed. The half-life of the mixed anhydride is short (two minutes or less), but it can be trapped chemically, and moreover, 0 is transferred from bicarbonate to orthophosphate during this reaction. P P -Diadenosine 5 -polypentaphosphate is an inhibitor of the enzyme from E. coli, while the equivalent diadenosine pyro- and polyhexa-phosphates are not. It has been suggested that the two molecules of ATP and the bicarbonate bind at the active site of the enzyme as shown in (35). Once the enzyme-bound mixed anhydride has been formed, this reacts with glutamine or ammonia to generate the enzyme-bound carbamate, which is finally phosphorylated by the second molecule of ATP (Scheme 10). 

Water followed by 2,6-didiloroquinone N-dilorimide added to a soln. of diadenosine 5 -pyrophosphate in pyridine-dimethylformamide, and heated 2hrs. on a steam bath adenosine 5 -phosphate. Y 77%. F. e. and reactions s. K.-J. Chong, S.-S. Pong, and T. Hata, Bull. Chem. Soc. Japan 43, 2571 (1970). 

A cytoplasmic factor is postulated to be responsible for the initiation of the S phase, and various investigators have demonstrated that DNA synthesis can be initiated by extracts of He La cells (Friedman and Mueller, 1968 Kumar and Friedman, 1972), L cells and ascites cells (Thompson and McCarthy, 1968), and embryos and eggs of Xenopus (Benbow and Ford, 1975). Although these factors are thought to be proteins, their exact nature and mechanisms of action are unknown. Recently it was suggested that diadenosine-tetra-phosphate (Ap4A) may act as an initiator of DNA replication in animal cells (Grummt, 1978). 

Fig 2 Typical flash-driven ATP formation assayed hy luminescence from the I uciferin-1 uciferase system. The reaction mixture contained 50 mM sorihtol, 50 rriM tricin-KOH pH 8.5, 3 mM MgCl2 0.1 mM methyl viologen with 15 kg Chi mt, LKB I uciferin-1 ucif erase reagent, 5 vM diadenosine penta-phosphate, 1 mM Pi,... 

Fig. 11. Two-dimensional correlated spectrum of the following mixture ATP, ADP, AMP, inorganic phosphate, pyrophosphate, adenosine tetraphosphate (A4P), diadenosine 5, S"-tetraphosphate (AP4A), and GdCl,. The labeling is consistent with Fig. 10 with the following additions diagonal peaks k and 1 (—23.7 and —23.9 ppm) represent the P- and y-phosphorus resonances of A4P and the p resonances of AP4A, respectively the off- diagonal peak h correlates the

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