41708-91-2Relevant articles and documents
Facile and Selective Synthesis of Diadenosine Polyphosphates through Catalysis by Leucyl t-RNA Synthetase Coupled with ATP Regeneration
Nakajima, Hiroshi,Tomioka, Isao,Kitabatake, Senji,Dombou, Munehiko,Tomita, Kosuke
, p. 615 - 624 (2007/10/02)
Leucyl t-RNA synthetase from a thermophilic bacterium, Bacillus stearothermophillus, effectively catalyzed the synthesis of p1,p4-di(adenosine 5'-)tetraphosphate (Ap4A), p1,p5-di(adenosine 5'-)pentaphosphate (Ap5A) and adenosine 5'-tetraphosphate (p4A).In particular, when the reaction was coupled with an ATP recycling system involving thermostable acetate kinase and adenylate kinase, Ap4A and Ap5A were produced selectively in high yields.This reaction is selective, gives high yields and does not require protection of the functional groups of nucleotides, and also it can be carried out in an aqueous solution.This method is superior to the conventional organic synthesis and provides a practical means of the synthesizing diadenosine polyphosphates (ApnA), biologically important compounds.
Species- or isozyme-specific enzyme inhibitors. IV. Design of a two-site inhibitor of adenylate kinase with isozyme selectivity
Hampton,Kappler,Picker
, p. 638 - 644 (2007/10/02)
The ATP analogues 6-(n-butylamino)-, 6-(di-n-butylamino)-, and 6-(n-butylthio)-9-β-D-ribofuranosylpurine 5'-triphosphate have been synthesized and studied as inhibitors and/or substrates of the rat muscle adenylate kinase isozyme (AK M) and the rat liver isozymes AK II and III. The 6-NH(n-Bu) and 6-S(n-Bu) analogues were substrates (V(max) relative to ATP, 13-190%) of the three AK isozymes, whereas the 6-N(n-Bu)2 analogue was a weak substrate and a competitive inhibitor of AK M and AK III. The affinities of the analogues relative to ATP [K(M) (ATP)/K(M) or K(i)] were 0.03-0.075 for AK III and 0.14-0.28 for AK M, and affinities for AK M exceeded those for AK III by factors of 2.3-7.0 P1, P6-Di(adenosine-5') pentaphosphate (Ap5A) was synthesized by an improved method and was found to be a potent two-site inhibitor (K(i) = 0.28 μM), competitive toward AMP or ATP, for the three AK isozymes. 8-SEt-Ap5A also behaved as a two-site inhibitor; the 8-SEt group reduced the affinity for AK M 12-fold but increased the affinity for AK II and III 4-fold, resulting in ca. 45-fold more effective inhibition of AK II and III (K(i) = 0.07 μM) than of AK M (K(i) = 3.25 μM). The 8-SEt group of 8-SEt-ATP likewise reduced affinity for the ATP site of AK M but enhanced affinity for the ATP sites of AK II and III, resulting in at least 30-fold more effective inhibition of AK II and III. 8-SEt-AMP inhibited AK II and III noncompetitively (K(i) = 21-24 mM) with respect to AMP, indicating that the 8-(ethylthio) adenosine moiety of 8-SEt-Ap5A probably binds to the ATP sites of these isozymes. 8-SEt-Ap5A had ca. 1000-fold more affinity for AK II or III than did 8-SEt-ATP. The findings indicate that isozyme-selective inhibitory effects of a substrate derivative can be imparted to a two-site inhibitor, leading to significant enhancement of inhibitory potency.