Adenylic acid-2 -phosphate

Adenosine-3 -monophosphoric acid hydrate [3 -adenylic acid, 3 -AMP] [84-21-9] M 347.3, m 197°(dec, as 2H2O), 210°(dec), m 210°(dec), [a]s46 -50° (c 0.5, 0.5M Na2HP04), pK 3.65, pKz 6.05. It crystallises from large volumes of H2O in needles as the monohydrate, but is not very soluble in boiling H2O. Under acidic conditions it forms an equilibrium mixture of 2 and 3 adenylic acids via the 2, 3 -cyclic phosphate. When heated with 20% HCl it gives a quantitative yield of furfural after 3hours, unlike 5 -adenylic acid which only gives traces of furfural. The yellow monoacridine salt has m 175°(dec) and... 

The isomerism existing between the pairs of nucleotides was attributed to the different locations of the phosphoryl residues in the carbohydrate part of the parent nucleoside,49 63 since, for instance, the isomeric adenylic acids are both hydrolyzed by acids to adenine, and by alkalis or kidney phosphatase to adenosine. Neither is identical with adenosine 5-phosphate since they are not deaminated by adenylic-acid deaminase,68 60 and are both more labile to acids than is muscle adenylic acid. An alternative explanation of the isomerism was put forward by Doherty.61 He was able, by a process of transglycosidation, to convert adenylic acids a" and 6 to benzyl D-riboside phosphates which were then hydrogenated to optically inactive ribitol phosphates. He concluded from this that both isomers are 3-phosphates and that the isomerism is due to different configurations at the anomeric position. This evidence is, however, open to the same criticism detailed above in connection with the work of Levene and coworkers. Further work has amply justified the original conclusion regarding the nature of the isomerism, since it has been found that, in all four cases, a and 6 isomers give rise to the same nucleoside on enzymic hydrolysis.62 62 63 It was therefore evident that the isomeric nucleotides are 2- and 3-phosphates, since they are demonstrably different from the known 5-phosphates. The decision as to which of the pair is the 2- and which the 3-phosphate proved to be a difficult one. The problem is complicated by the fact that the a and b" nucleotides are readily interconvertible.64,64... 

The second step in the conversion of inosinic acid to guanylic acid is the aminolysis of xanthylic acid with glutamine by xanthosine-5 -phosphate aminase [65]. This aminase, isolated fromf. coli B, is inhibited allosterically by adenosine and adenylic acid [320], and it is also inhibited by psicofuranine (9-0-D-psicofuranosyladenine) (LXXIV) [284, 321-326], which apparently is not... 

ADENOSINE PHOSPHATES. The adenosine phosphates include adenylic acid (adenosine monophosphate, AMP) in which adenosine is esteri-fied with phosphoric add at the 5/-position adenosine diphosphate (ADP) in which esterification at the same position is with pyrophosphoric acid,... 

The structure of firefly luciferin has been confirmed by total synthesis. The firefly emits a ycllow-grccn luminescence, and luciferin in this case is a benzthiazole derivative. Activation of the firefly luciferin involves the elimination of pyrophosphate from ATP widi the formation of an add anhydride linkage between the carboxyl group of luciferin and the phosphate group of adenylic acid forming luciferyl-adenylate. 

Ribonuclease T2 (5) was found in 1957 by Sato and Egami in Taka-diastase (12). Since the partially purified RNase T2 was found to preferentially attack phosphodiester bonds of adenosine-3 -phosphate in RNA (80), this enzyme had long been expected to be specific for adenylic acid phosphodiester bond if it could be completely purified. However, sufficiently purified RNase T2 showed no absolute base specificity (81, 82) and was found rather to split all phosphodiester bonds in RNA with a preference for adenylic acid bonds. Thus, RNase T2 is effective in the analysis of the base composition of RNA. 

Ribonuclease T2 is regarded as a nonspecific endoribonuclease [EC 2.7.7.17, ribonucleate nucleotido-2 -transferase (cyclizing)]. It preferentially splits the internucleotide bonds between the 3 -adenylic acid group and the 5 -hydroxyl group of adjacent nucleotides in RNA, with the intermediary formation of adenosine 2, 3 -cyclic phosphate and splits consequently all secondary phosphate ester bonds of other nucleotides in RNA via the nucleotides 2, 3 -cyclic phopshates. 

Adenosine 2, 3 -cyclic phosphate is scarcely accumulated, though other nucleoside 2, 3 -cyclic phosphates are accumulated as intermediates. This result suggests that the action of RNase T2 on RNA is owing to the cooperation of an adenylic acid specific endonuclease activity and a nonspecific exonuclease activity releasing mononucleotides from the 3 terminal. 

Ribonuclease Ua digestion of ApU has revealed reduced hydrolase activity in the second step of RNase U2 action (30). When 87.4% of ApU was readily degraded to produce uridine and adenosine 2, 3 -cyclic phosphate, no 3 -adenylic acid was detected. After exhaustive degradation of ApU, hydrolysis of adenosine 2, 3 -cyclic phosphate occurred and 3 -adenylic acid gradually appeared. 

Adenosine 5 -phosphate is also known as AMP (for adenosine monophosphate) or adenylic acid. If deoxyribose replaces ribose in adenosine 5 -phosphate, the terminology is dAMP or deoxyadenylic acid. The abbreviated names for some ribonucleotides and deoxyribonucleotides are listed below. 

Fig. 17.2. Chemical structures of some nucleotides adenosine-5 -phosphate or 5 -adenylic acid adenosine-3 -phosphate or 3 -adenylic acid adenosine-3, S -disphosphate...

A.7.1 Esterification of Acids using Carbodiimides. The formation of anhydrides from carboxylic acids, thiocarboxylic acids, sulfonic acids and phosphorous acids are discussed in Section 2.4.S.2. In this section only special cases of anhydride formation are described. Mixed anhydrides of amino acids and adenylic acid are produced from the corresponding acids using DCC as the condensation agent. ° Mixed anhydrides not containing amino acids, such as butyryl adenate, adenosine 5 -phosphosulfate and p-nitrophenyl-thymidine-5-phosphate are also obtained. 

ADENOSINE PHOSPHATE ADENOSINE-5 -PHOSPHATE ADENOSINE-5 -PHOSPHORIC ACID ADENOVITE ADENYL ADENTT.IC ACID tert-ADENYLIC ACID A5MP 5-AMP 5 -AMP AMP (nucleotide) CARDIOMONE ERGADENYLIC ACID LYCEDAN MUSCLE ADENYLIC ACID MY-B-DEN MYOSTON NSC-20264 PHOSADEN PHOSPHADEN PHOSPHENTASIDE... 

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