Synthesis of a hoechst 32258 analogue amino acid building block for directincorporation of a fluorescent, high-affinity DNA binding motif into peptides
C. Behrens et al., Synthesis of a hoechst 32258 analogue amino acid building block for directincorporation of a fluorescent, high-affinity DNA binding motif into peptides, BIOCONJ CHE, 12(6), 2001, pp. 1021-1027
The synthesis of a new versatile "Hoechst 33258-like" Boc-protected amino a
cid building block for peptide synthesis is described. It is demonstrated t
hat this new ligand is an effective mimic of Hoechst 33258 in terms of DNA
affinity and sequence specificity. Furthermore, this minor groove binder wa
s conjugated to a DNA condensing peptide (KSPKKAYK) by continuous solid-pha
se peptide synthesis, and the conjugate exhibited increased DNA affinity (c
a. 10-fold), but similar sequence preference compared to Hoechst 33258 as a
nalyzed by DNaseI footprinting. Finally, the fluorescence quantum yield of
the new chromophore is found to increase 30% upon binding to double strande
d DNA.