title: DNA sequence recognition by Hoechst 33258 conjugates of hairpin pyrrole/imidazole polyamides.
abstract: A series of hairpin pyrrole/imidazole polyamides linked to a Hoechst 33258 (Ht) analogue (5-7) were synthesized on solid-phase by adopting an Fmoc technique using a series of PyBOP/HOBt mediated coupling reactions. The dsDNA binding properties of Ht-polyamides 5-7 were determined by thermal denaturation experiments. Hairpin Ht-polyamides 5-7 bound to dsDNA sequences 16 and 18 show DeltaTm values that are 14-18 degrees higher than linear Ht-polyamides bound to the same sequences. All three Ht-polyamides were found to be selective for their 9-bp match dsDNA sequences, supporting a relative stronger interaction of an Im/Py anti-parallel dimer with an appropriately positioned G/Cbp rather than sequences containing only A/Tbps. In addition, Ht-polyamides 5 and 7 showed a 20-fold preference for a properly placed G/Cbp over a C/Gbp, while 6 showed a 10-fold preference.
authors: Department of Chemistry and Biochemistry, University of California at Santa Barbara, Santa Barbara, CA 93106, USA.
authors: Bryan J
authors: BJ
authors: Correa
authors: Daniele
authors: D
authors: Canzio
authors: Alexandra L
authors: AL
authors: Kahane
authors: Putta Mallikarjuna
authors: PM
authors: Reddy
authors: Thomas C
authors: TC
authors: Bruice