合成DNA聚（氨基2dA-dT）双链体在高盐和醇水溶液中的构象。
Conformation of the synthetic DNA poly(amino2dA-dT) duplex in high-salt and aqueous alcohol solutions.
作者信息
Vorlícková M, Sági J, Szabolcs A, Szemzö A, Otvös L, Kypr J
机构信息
Institute of Biophysics, Czechoslovak Academy of Sciences, Brno.
出版信息
Nucleic Acids Res. 1988 Jan 11;16(1):279-89. doi: 10.1093/nar/16.1.279.
It has previously been demonstrated by other workers that the duplex of a synthetic DNA poly(amino2dA-dT) undergoes a salt-induced conformational isomerization. We show in the present work using circular dichroism that the same isomerization is induced in poly(amino2dA-dT) by various alcohols. The isomerization was originally identified as the B-to-Z and then B-to-A conformational transition of DNA but we demonstrate that the high-salt or alcohol conformation of poly (amino2dA-dT) is the non Z-DNA zig-zag double helix we have previously observed with poly(dA-dT) and called X-DNA. X-DNA is a cesium cation specific conformation of poly(dA-dT) while no similar cation specificity is observed with poly(amino2dA-dT). Thus it appears that the extra amino group attached to A and cesium cations make the same thing; they probably dehydrate the double helix minor groove and relieve its conformational variability. Poly(amino2dA-dT) is exceptionally stable in X-DNA and conditions inducing it are mild, which opens the door to assess its molecular structure.
此前其他研究人员已证明，合成DNA聚（氨基2dA - dT）的双链体会发生盐诱导的构象异构化。我们在当前工作中利用圆二色性表明，各种醇类也能在聚（氨基2dA - dT）中诱导相同的异构化。这种异构化最初被确定为DNA的B型到Z型，然后是B型到A型的构象转变，但我们证明聚（氨基2dA - dT）的高盐或醇类构象是我们之前在聚（dA - dT）中观察到并称为X - DNA的非Z - DNA锯齿状双螺旋。X - DNA是聚（dA - dT）的一种铯阳离子特异性构象，而在聚（氨基2dA - dT）中未观察到类似的阳离子特异性。因此，似乎连接在A上的额外氨基和铯阳离子起到了相同的作用；它们可能使双螺旋小沟脱水并减轻其构象变异性。聚（氨基2dA - dT）在X - DNA中异常稳定，且诱导其形成的条件较为温和，这为评估其分子结构打开了大门。
Zotero 插件