Sequence specificity, calicheamicins

The calicheamicin oligosaccharide 5 (Scheme 2) was shown to bind with low micromolar affinity to its target site with similar selectivity as compared to calicheamicin Yi (3) [38] (see also references in [39]). This unique property could be used to compete off specific transcripton factors from their target sequence at the expected concentrations [39]. The limited selectivity and potency, however, were not sufficient for a meaningful biological application and the recent progress in the synthesis of complex oligosaccharides allowed this approach to be explored further. 

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