Diadenosine tetraphosphate

Diadenosine 5-tetraphosphate (Ap4A) Oxidative or heat stress Chapters 28, 29... 

Liu G, Bryant RT, Hilderman RH, Isolation of a tripeptide from a random phage peptide library that inhibits PI, P4-diadenosine 5 -tetraphosphate binding to its receptor, Biochemistry, 35 197-201, 1996. 

In S. typhimurium a series of imusual nucleotides such as P, P -diadenosine 5 -tetraphosphate (ApppA or AP4A) accumulate. The related compoimds App-pGpp (with a 3 pyrophosphate), ApppG, AppG, and ApppA also accumulate and appear not only in bacteria but in eukaryotes as well. They are formed as a side product in aminoacylation of transfer RNAs (Ghapter Lee et al ° proposed that AP4A... 

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. 

Detailed studies of hydrolysis and ligand exchange kinetics137-139 with 5 -GMP and 5 -AMP and with diadenosine tetraphosphate have illustrated that kinetics might be much more important than previously thought. 

Following structure-activity studies, the adenylate is thought to be stabilized within a cleft formed between the two subdomains of the activation domain [41,58], The rate is thus related to the formation, presence, and stability of this mixed anhydride with respect to PPi, and at high MgATP2 concentrations, with respect to ATP in the formation of diadenosine tetraphosphate (A2P4). Thus a high rate of the amino acid-dependent isotope exchange does not necessarily reflect the efficiency of adenylate formation, and certainly not the efficiency of incorporation of an amino acid into peptidyl intermediates or the final product. 

DAPI (46-diamino-2-phenylindole) 23, 24, 53,57 degradosome 107, 108, 121 diadenosine tetraphosphate 117 diadenosine-5, 5 "-P1, P4 tetraphosphate... 

Ap4A (Ap(4)A Pi,Ps-diadenosine tetraphosphate) is an endogenous agent used in synthetic form as a pharmacological tool in purine receptor classification studies. It is a PURINE p2 RECEPTOR AGONIST, particularly active at the pyrimidine-preferring receptor subtypes. Ap(4)A Ap4A. 

With these points in mind, some characteristics of the receptors are noted, particularly their sensitivities to the natural nucleotides ADP (adenosine diphosphate), ATP (adenosine triphosphate), UTP (uridine triphosphate), UDP (uridine diphosphate) and Ap4A (Ap(4)A P1.P5-diadenosine tetraphosphate). 

Several inhibitors are known that bind to the adenosine site of PARP (19). These inhibitors include 6-bromo-2 -deoxyuridine, caffeine, 5-bromouracil, diadenosine-tetraphosphate, 1-methyladenine, 5-nitrouracil, theophylline, theobromine, thymidine, and other compounds. These compounds are not as well studied as the nicotinamide analogs. In addition, it is not known whether these compounds can interact with the adenosine (A,) receptors that are involved in modulation of synaptic transmission and neuroprotective effects. 

The recent establishment of a link between ribonucleotide metabolism, specifically the synthesis of the cellular metabolite, diadenosine tetraphosphate, and its relationships with adenosine diphosphate-ribosylation reactions in the cell, presents a significant new target. 

T. Alderson Diadenosine Tetraphosphate A New Target for Cancer Chemotherapy... 

Inhibition of SV40 Replication In Vitro by Poly(ADP-Ribosyl)ated Diadenosine Tetraphosphate... 

Zamecnik, P. C., Stephenson, M. L., Janbway, C. M. and Randerath, K. (1966) Enzymatic synthesis of diadenosine tetraphosphate and diadenosine triphosphate with a purified lysyl-SRNA synthetase. Biochem. Biophys. Res. Common. 24, 91-97. 

J. W. Booth and G. Guidotti (1995). An alleged yeast polyphosphate kinase is actually diadenosine-5, 5 "-P1,P4-tetraphosphate a,/3-phosphorylase. J. Biol. Chem., 270, 19377-19382. 

---