Apurinic acid

RNA is relatively resistant to the effects of dilute acid, but gentle treatment of DNA with 1 mM HCl leads to hydrolysis of purine glycosidic bonds and the loss of purine bases from the DNA. The glycosidic bonds between pyrimidine bases and 2 -deoxyribose are not affected, and, in this case, the polynucleotide s sugar-phosphate backbone remains intact. The purine-free polynucleotide product is called apurinic acid. 

In another series of experiments, a novel approach to the determination of nucleotide sequence was adopted by A. S. Jones, Stacey, and their co-workers. For example, when calf thymus DNA was treated with mercaptoacetic acid in the presence of zinc chloride and anhydrous sodium sulfate, it yielded aldehydo-apurinic acid bis(carboxymethyl) dithioacetal. When degraded with dilute alkali, this afforded dialyzable fragments, which were separated into at least 20 components. Some were identified, including mono-, di-, and tri-nucleotides, thereby revealing that DNA contain regions of at least three linked pyrimidine nucleotides. The same procedure was applied to the DNA isolated from M. phlei ... 

The Nucleotide Sequence in Deoxypentosenucleic Acids. Part II. The Alkaline Degradation of Calf-thymus aldehydo Apurinic Acid Di(carboxymethyl) Dithioacetal, A. S. Jones, D. S. Letham, and M. Stacey, J. Chem. Soc., (1956) 2579-2583. 

Deoxyribonucleic acids readily undergo hydrolysis whereby purine bases are removed to give a derived polynucleotide originally named thymic acid, but now often called apurinic acid. Hydrolysis may be carried out with dilute mineral acid, but recently apurinic acids have been prepared by fission at room temperature with an acidic, ion-exchange resin.236 Under carefully controlled conditions, removal of the purines can be performed quantitatively without destroying the polynucleotide nature of the material and without altering the inter-pyrimidine ratios of the original material.23 ... 

Cleavage here by weak acids (pH 2) yields an "apurinic acid"... 

AP-1 (Activator Protein) 576, 577 Apoferritin 842 Apoptosis 574, 619 Apple motif of proteins 367 Apurinic acid 250 Apyrimidinic acid 255 Aquaporins 411,412 Arabidopsis thaliana genome 12, 29 Arabinan 177 Arabinogalactan 431 L-Arabinose (Ara) 163... 

Hydrolysis of DNA yields free purine bases and, under mild conditions, apurinic acid which can be further degraded by more severe conditions to pyrimidine sequences pPyp...Pyp (Michelson 1963, p. 368). Kirk (1963, 1967) used mild hydrolysis to liberate the purines which were then estimated after separation by column chromatography ... 

A column (17 cm x 1 cm) of Zeo-Karb 225 was washed with 0.03 N HCl (at least 20 ml) and an acid hydrolysate of DNA was loaded. Apurinic acids were eluted with 0.03 N HCl (50 ml) and then guanine and adenine were eluted separately with 2 N HCl. This is part of an accurate chemical method for measurement of DNA composition (Kirk, 1967). 

Fig. 7. Effect of native DNA, denatured DNA and yeast RNA on the ultraviolet absorption spectra of distamycin (A), distamycin/4 (B) and distamycin/5 (C), in 0.01 M Tris-HC1 buffer (pH 7.0). Curve 1 is the spectrum of free antibiotics. Other curves are spectra of the antibiotics in the presence of yeast RNA (curve 2), denatured DNA (curve 3), native DNA (curve 4), apurinic acid (curve 5) and apyrimidinic DNA (curve 6) at a molar antibiotic/nuclei acid-P ratio of 0.025. Chandra et al.21 ...

For these reasons we have used depurinating conditions (15 min, lOO C, 90 % HCOOH) which separated adenine, guanine and the platinum-DNA adducts from apurinic acid. These products were resolved by high voltage paper electrophoresis at pH 2. The paper was cut into 1 cm strips which were eluted in water and the profile of platinum concentration was determined by flameless atomic absorption. Under these conditions, the apurinic acid migrated toward the positive electrode while the purine bases and the adducts migrated toward the negative electrode. For all three compounds, less than 10 % of the platinum was detected on the apurinic acid, even at r 0.4. The electrophoresis profiles of hydrolysed platinum-DNA complexes formed by eis-DDP, ii ans-DDP and... 

Apurine acids polynucleotides which have been subjected to brief treatment with mild acid, which removes the purines and leaves the phosphate, pentose and pyrimidines. 

DNA exhibits rather different properties from RNA in its susceptibility to acid and alkaline hydrolysis. The extreme acid lability of the iV-gly-cosy 1-purine linkages in DNA allows the quantitative liberation of free purines by very mild acid treatment, leaving a high molecular weight residue (called apurinic acid or thymic acid) complete in pyrimidine, deoxy-ribose, and phosphate composition 169), DNA, however, is quite stable to alkaline action since the absence of a hydroxyl group on carbon 2 of deoxy-ribose precludes the possibility of labilization through a cyclic 2, 3 -phos-phate intermediate. 

Dilute acid selectively cleaves the glycosidic linkage of purines in DNA, yielding apurinic acid. It does not act on RNA, except when hot and very concentrated (see Section 3.2.1). 

Both the early studies and more recent determination of the specificity of anti-denatured DNA antibodies have shown that the responses vary according to the sera used. The variability of the antigenic determinants is reflected by the difference of susceptibility of the reaction to inhibition by enzymatic products of degradation of DNA of different size, or by apurinic acid. The reactions of several sera with denatured DNA are inhibited by purines, others by pyrimidines or by both. The size of the antigenic determinants is equally variable (see Levine and Stollar, 1968). 

Wang, S.Y., Reversible behavior of the ultra-violet irradiated deoxyribonucleic acid and its apurinic acid, Nature, 188, 844,1960. 

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