Xodo L E, Manzini G, Quadrifoglio F, Yathindra N, van der Marel G A, van Boom J H
Department of Biochemistry, Biophysics and Macromolecular Chemistry, University of Trieste, Italy.
J Biomol Struct Dyn. 1989 Jun;6(6):1217-31. doi: 10.1080/07391102.1989.10506546.
A number of fully self-complementary oligodeoxynucleotides have been synthesized and examined for their ability to assume the left-handed Z-DNA conformation in high salt solutions. The B- and Z-forms are identified by circular dichroism spectra, covering both the long- (220-300 nm) and short-wavelength (185-220 nm) regions, the latter showing CD bands very useful for identifying the sense of the helix winding. The main results of the study can be summarized as follows: a) sequences composed by AT and CG blocks do support the B to Z transition, even when the AT contents amounts to 50%; b) the occurrence of consecutive purine-purine or pyrimidine-pyrimidine dyads does not inhibit the B to Z transition, although a stronger reduction of water activity is required; c) (AC)n and (GT)n containing oligonucleotides do undergo the B to Z transition in solution; d) a millimolar quantity of Ni2+ concomitant with 5 M NaClO4 is found to be very effective in bringing about the B to Z transition in most of the sequences considered in this study.
已经合成了许多完全自互补的寡脱氧核苷酸，并检测了它们在高盐溶液中呈现左手Z-DNA构象的能力。通过圆二色光谱来识别B型和Z型，该光谱覆盖长波长（220 - 300nm）和短波长（185 - 220nm）区域，后者显示的CD带对于识别螺旋缠绕方向非常有用。该研究的主要结果可总结如下：a）由AT和CG块组成的序列确实支持B向Z的转变，即使AT含量达到50%；b）连续嘌呤-嘌呤或嘧啶-嘧啶二联体的出现并不抑制B向Z的转变，尽管需要更强程度地降低水活性；c）含（AC）n和（GT）n的寡核苷酸在溶液中确实会发生B向Z的转变；d）发现1毫摩尔量的Ni2+与5M高氯酸钠同时存在时，对于本研究中考虑的大多数序列实现B向Z的转变非常有效。
