O'Donnell M J, Rajur S B, McLaughlin L W
Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02167, USA.
Bioorg Med Chem. 1995 Jun;3(6):743-50. doi: 10.1016/0968-0896(95)00055-l.
A small Hoechst-like DNA groove-binding fluorophore carrying a terminal bromoacetimido linker has been synthesized. Individual diastereomeric oligodeoxynucleotide dodecamers containing a thiol-based linker attached to an internucleotide phosphoramidate within a sequence of dA-dT residues were each covalently labeled with the new fluorophore. One isomer of the DNA-fluorophore conjugate (Isomer B) hybridizes to the complementary single-stranded target DNA and the presence of the tethered fluorophore results in both increased duplex stability and an enhanced fluorescent signal, presumably due to the fluorophore binding in the dA-dT rich minor groove. Duplex stability is increased by 2-3 degrees C and the fluorescence quantum yield for the fluorophore increases four-fold. In contrast, the other diastereomer (Isomer A) exhibits reduced helix stability (approximately 2 degrees C) and only slight changes in fluorescence intensity upon hybridization.
已合成一种带有末端溴乙酰亚胺连接基的类似Hoechst的小DNA沟槽结合荧光团。在dA-dT残基序列内，含有连接到核苷酸间磷酰胺酯上的硫醇基连接基的各个非对映异构寡脱氧核苷酸十二聚体，均用新的荧光团进行共价标记。DNA-荧光团共轭物的一种异构体（异构体B）与互补的单链靶DNA杂交，并且连接的荧光团的存在导致双链稳定性增加和荧光信号增强，推测是由于荧光团结合在富含dA-dT的小沟槽中。双链稳定性提高了2-3摄氏度，荧光团的荧光量子产率增加了四倍。相比之下，另一种非对映异构体（异构体A）表现出降低的螺旋稳定性（约2摄氏度），杂交时荧光强度仅有轻微变化。
