5’-Adenylic acid

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... 

FIGURE 11.13 Structures of the four cotntnou ribonucleotides—AMP, GMP, CMP, and UMP—together with their two sets of full uatnes, for example, adeuosiue 5 -mouophosphate and adenylic acid. Also shown is the nucleoside 3 -AMP. 

The mixed sulfuric phosphoric anhydride (PAdoPS or PAPS) of 3 -phospho-5 -adenylic acid is named as an acyl sulfate ... 

Another cyclization of 3 -adenylic acid (3 -AMP) to 2, 3 -cyclic adenylic acid (2, 3 -cAMP) took place by condensation with carbiminodiimidazole (or iV-cyanoimidazole) in aqueous or anhydrous medium. It is supposed that the reaction of 3 -AMP probably proceeds via a phosphoric imidazolide [9]... 

Imidazolides of adenylic acid (ImpA) or uridylic acid (ImpU) are polycondensed to oligonucleotides by means of Zn2+ ions. 1673 The resulting phosphordiester bond was found to be of the 2, 5 type. In the reaction of nucleoside 5 -phosphoric acid methyl ester with ImpA in the presence of MgC, 2, 5 -dinucleotides are formed six to nine times more frequently than the corresponding 3, 5 compounds. 63 Polycondensations of ImpA in aqueous solution in the presence of various divalent metal ions lead to short oligo-adenylic acids (pA) (n = 1—5) mainly with 2, 5 -intemucleotide linkages. With Pb2+, for example, the total yield of oligomers was as high as 57%. 1683 1693... 

Figure 3.1 Two essential steps of chemical reaction of formaldehyde (HCHO) with nucleic acid exemplified by adenine that are similar to formaldehyde-protein reactions, (a) Addition reaction as the first step, resulting in a methylol derivative, methylol adenylic acid (b) Second step is a condensation reaction, a stable product methylene-bis-adenylic acid is derived between the methylol derivative and another adenine. Reproduced with permission from Shi et al.,AIMM 2001 9 107-116. 

Several enzymes have been immobilized in sol-gel matrices effectively and employed in diverse applications. Urease, catalase, and adenylic acid deaminase were first encapsulated in sol-gel matrices [72], The encapsulated urease and catalase retained partial activity but adenylic acid deaminase completely lost its activity. After three decades considerable attention has been paid again towards the bioencapsulation using sol-gel glasses. Braun et al. [73] successfully encapsulated alkaline phosphatase in silica gel, which retained its activity up to 2 months (30% of initial) with improved thermal stability. Further Shtelzer et al. [58] sequestered trypsin within a binary sol-gel-derived composite using TEOS and PEG. Ellerby et al. [74] entrapped other proteins such as cytochrome c and Mb in TEOS sol-gel. Later several proteins such as Mb [8], hemoglobin (Hb) [56], cyt c [55, 75], bacteriorhodopsin (bR) [76], lactate oxidase [77], alkaline phosphatase (AP) [78], GOD [51], HRP [79], urease [80], superoxide dismutase [8], tyrosinase [81], acetylcholinesterase [82], etc. have been immobilized into different sol-gel matrices. Hitherto some reports have described the various aspects of sol-gel entrapped biomolecules such as conformation [50, 60], dynamics [12, 83], accessibility [46], reaction kinetics [50, 54], activity [7, 84], and stability [1, 80],... 

The first nucleotides to be investigated were inosinic and adenylic acids... 

The bearing which these discoveries have had on the elucidation of the structure of ribopolynucleotides will be discussed later. It is important to stress here, however, that, for most purposes, the older methods of preparing nucleotides have been superseded by procedures which yield separate isomers of each. Of the techniques mentioned above, paper chromatography iB mainly of analytical value, and is the most convenient method for the qualitative detection of isomeric adenylic acids. The only disadvantage of this method is that the isomers are not completely separable from muscle adenylic acid. The presence of the latter, however, can be readily detected by hydrolyzing it to adenosine by means of the specific 5-nucleotidase present in snake venoms,66 or by deamination by a specific enzyme... 

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... 

Knowledge of the coenzyme forms of vitamin Bi2 has increased steadily. The first coenzyme of Bi2 isolated from bacteria had similarities to pseudovitamin Bi2 it contained adenylic acid instead of 5,6-dimethyl-benzimidazole, but differed in lacking cyanide and having an extra molecule of adenine which was assumed to be bound to the cobalt atom by the coordination site, often occupied by cyanide (B24). This coenzyme, adenylcobamide, was completely inactive for Ochromonas malhamensis, but active for Escherichia coli 113-3. 

Adenine Adenosine Adenylic acid Adenosine monophosphate (AMP) Adenosine diphosphate (ADP) Adenosine triphosphate (ATP)... 

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