Chain length-dependent association of distamycin-type oligopeptides with A·T and G·C pairs in polydeoxynucleotide duplexes

摘要: Abstract Different binding affinities of various distamycin analogs including the deformylated derivative with poly(dA-dC)·poly(dG-dT) were investigated using CD measurements. The inhibitory effect distamycins on DNAase I cleavage activity DNA duplexes strongly supports data. base specificity ligand interaction duplex depends chain length analogs. Netropsin, distamycin-2 and distamycin-3 show no to dG·dC containing sequences at moderate ionic strength are classified as highly dA·dT specific. In contrast having three, four or five methylpyrrolecarboxamide groups also forms more less stable complexes dG·dC-containing duplexes. These ligands possess a lower basepair specificity. correlation between behavior oligopeptide structure shows that presence number hydrogen acceptor donor sites determines sequence additional pairs becomes essential when exceeds n = 3.