into the ODN. The fluorescence properties, thermal denaturation experiments, absorption, and circular dichroism (CD) studies with the X- and Y-modified ODNs in the form of matched homo- and heteroduplexes consistently suggested (i) that the orientation of the pyrene moiety is outside the helix of the nucleic acid duplexes containing a dT−d/rA base pair at the 3‘-end of the modification site for both X
含有2'- DNA探针核苷酸(ODN)Ñ(
芘-1-基) -基团的构象锁定的核苷[2' - - ñ - (
芘-1-基)羰基-氮杂
环丁烷胸苷,阿泽
吡(X),和2'- N-(
吡喃-1-基)羰基-氮杂-ENA
胸苷,氮杂-ENA-pyr(Y)],表明它们与互补RNA的结合比与DNA的结合更牢固。的阿泽
吡(X含有核苷酸与互补的DNA和RNA双链体)表现出的荧光强度的增加(在λ测定
EM取决于最近邻在3'-端≈376纳米)X [
DA〜12( -20倍)> dG(〜9-20倍)> dT(〜2.5-20倍)> dC(〜6-13倍)]。它们具有很高的荧光量子产率(Φ与单链ODN相比,F = 0.13-0.89)。氮杂ENA-PYR(Ý)改性寡核苷酸,在另一方面,显示了荧光强度的增强只与互补的DNA(1.4-3.9倍,Φ ˚F = 0.16-0.47); 一个在荧光非常小的增加也与互补RNA观察到的(1.1-1.7倍,Φ