Ikehara M, Fukui T, Kakiuchi N
Nucleic Acids Res. 1977 Apr;4(4):989-1000. doi: 10.1093/nar/4.4.989.
Poly (2'-amino-2'-deoxyadenylic acid) [poly (Aa)] was prepared from chemically synthesized 2'-amino-2'-deoxy-ADP by the catalysis of polynucleotide phosphorylase. Poly (Aa) showed a similar UV absorption spectra to poly (A), but quite different CD spectra at pH 7.0 and 5.7. At the former pH it showed a single negative Cotton band and at the latter a curve with a large splitting of bands. Acid titration of poly (Aa) suggested protonated form below pH 7.0. Temperature absorption profiles and their dependency on sodium ion concentration suggested an ordered structure for poly (Aa) which is stabilized by stacking of bases and intrastrand interaction between 2'-amino and internucleotidic phosphate groups. Poly (Aa) forms a 1:2 complex with poly (U) at neutrality and its Tm was 45 degrees in the presence of 0.15M sodium ion.
聚(2'-氨基-2'-脱氧腺苷酸)[聚(Aa)]由化学合成的2'-氨基-2'-脱氧-ADP在多核苷酸磷酸化酶的催化下制备而成。聚(Aa)的紫外吸收光谱与聚(A)相似,但在pH 7.0和5.7时的圆二色光谱却大不相同。在前者pH值下,它呈现出单一的负性科顿带,而在后者pH值下则呈现出带明显分裂的曲线。聚(Aa)的酸滴定表明在pH 7.0以下为质子化形式。温度吸收曲线及其对钠离子浓度的依赖性表明聚(Aa)具有有序结构,该结构通过碱基堆积以及2'-氨基与核苷酸间磷酸基团之间的链内相互作用得以稳定。聚(Aa)在中性条件下与聚(U)形成1:2复合物,在0.15M钠离子存在时其解链温度为45摄氏度。