Molecular Recognition of DNA by Hoechst Benzimidazoles: Exploring Beyond the Pyrrole-Imidazole-Hydroxypyrrole Polyamide-Pairing Code
作者:Thomas G. Minehan、Konstanze Gottwald、Peter B. Dervan
DOI:10.1002/1522-2675(20000906)83:9<2197::aid-hlca2197>3.0.co;2-n
日期:2000.9.6
A series of three-ring analogs of the minor-groove-binding molecule Hoechst 33258 (1), consisting of benzimidazole (B), imidazopyridine (P), and hydroxybenzimidazole (H) monomers, have been synthesized in order to investigate both their sequence specificity and binding modes. MPE.Fe-II Footprinting has revealed the preference of both PBB and BBB ligands for 5'-WGWWW-3' and 5'-WCWWW-3' tracts, as well as A T-rich sequences. Affinity-cleavage titrations show no evidence for a 2:1 binding mode of these Hoechst analogs. Importantly, all derivatives are oriented in one direction at each of their binding sites. The implications of these results for the design of minor-groove-binding small molecules is discussed.