Theoretical studies on intratriplex DNA with 5-bromocytosine  

作　　者：杨林静 刘峁子 李清 王琛 白春礼 

出　　处：《Science China Chemistry》1998年第6期646-651,共6页中国科学（化学英文版）

基　　金：ProjectsupportedbytheNationalNaturalScienceFoundationofChina (GrantNo .2 95 2 30 4)andtheFoundationoftheChi neseAcademyofSciences

摘　　要：The relative stability of three intratriplex DNAs with substitution of 5-bromocytosines for cytosines in different strands and the corresponding unsubstituted intratriplex have been respectively investigated by molecular mechanics calculation. The results showed that intratriplex YTC with substitution occurring in strand III is the most stable and YTCY with substitution occurring in both strand I and III is the most unstable. Sugar conformations of the four intratriplexes are mainly C3′-endo. However, there are more C2′-endo sugar conformations in YTCY than in other intratriplexes, especially in strand I and III. Thus intratriplex YTCY is the combination of A-DNA and B-DNA, the other three intratriplexes are classical A-type DNA.The relative stability of three intratriplex DNAs with substitution of 5-bromocytosines for cytosines in different strands and the corresponding unsubstituted intratriplex have been respectively investigated by molecular mechanics calculation. The results showed that intratriplex YTC with substitution occurring in strand III is the most stable and YTCY with substitution occurring in both strand I and III is the most unstable. Sugar conformations of the four intratriplexes are mainly C3’-endo. However, there are more C2’-endo sugar conformations in YTCY than in other intratriplexes, especially in strand I and III. Thus intratriplex YTCY is the combination of A-DNA and B-DNA, the other three intratriplexes are classical A-type DNA.

关 键 词：5-bromocytosine intratriplex DNA molecular mechanics 

分 类 号：Q523[生物学—生物化学]