In 1990, Bai et al.first directly observed an unusual triple-stranded braid-likeconformation of denatured λ-DNA Hind Ⅲ in vitro with scanning tunneling microscopy(STM). The triple-stranded braid-like conformation pr...In 1990, Bai et al.first directly observed an unusual triple-stranded braid-likeconformation of denatured λ-DNA Hind Ⅲ in vitro with scanning tunneling microscopy(STM). The triple-stranded braid-like conformation presented in this work was dif-ferent from the model of the right-handed triple helix DNA proposed by otherauthors.In the triple helix model, the third strand winds round the major groove ofthe double helix DNA. Several studies indicated that the triple-stranded DNA, whichwas prepared by the reaction of homopurine and homopyrimidine or single-strandedDNA and doube-stranded DNA, had a low melting temperatue (T_m), a highabsorbance at 280 run in the unwinding process and was resistant to DNase展开更多
文摘In 1990, Bai et al.first directly observed an unusual triple-stranded braid-likeconformation of denatured λ-DNA Hind Ⅲ in vitro with scanning tunneling microscopy(STM). The triple-stranded braid-like conformation presented in this work was dif-ferent from the model of the right-handed triple helix DNA proposed by otherauthors.In the triple helix model, the third strand winds round the major groove ofthe double helix DNA. Several studies indicated that the triple-stranded DNA, whichwas prepared by the reaction of homopurine and homopyrimidine or single-strandedDNA and doube-stranded DNA, had a low melting temperatue (T_m), a highabsorbance at 280 run in the unwinding process and was resistant to DNase
