Seki J, Kuroda K, Ozaki H, Sawai H
Department of Chemistry, Faculty of Engineering, Gunma University, Kiryu City, Japan.
Nucleic Acids Symp Ser. 1993(29):71-2.
Double and triple helix formation of non-self complementary 2'-5' and 3'-5' linked oligonucleotides, 3'-5'(pA)7, 3'-5'(pU)7, 2'-5'(pA)7 and 2'-5'(pU)7, was studied using UV and CD spectroscopies. UV mixing curve and UV melting curve showed that 3'-5'(pA)7:3'-5' (pU)7 system could form double and triple helix, while 2'-5'(pA)7:2'-5'(pU)7 system could form only double helix and 3'-5'(pA)7:2'-5'(pU)7 system could form neither double nor triple helix under the condition examined. Thermodynamic parameters obtained from the UV melting curve indicate that the linkage type of oligonucleotides has profound effect on the helix formation.
利用紫外光谱和圆二色光谱研究了非自身互补的2'-5'和3'-5'连接的寡核苷酸3'-5'(pA)7、3'-5'(pU)7、2'-5'(pA)7和2'-5'(pU)7的双螺旋和三螺旋形成。紫外混合曲线和紫外熔解曲线表明，3'-5'(pA)7:3'-5'(pU)7体系可形成双螺旋和三螺旋，而2'-5'(pA)7:2'-5'(pU)7体系仅能形成双螺旋，在考察的条件下3'-5'(pA)7:2'-5'(pU)7体系既不能形成双螺旋也不能形成三螺旋。从紫外熔解曲线获得的热力学参数表明，寡核苷酸的连接类型对螺旋形成有深远影响。
