Incorporation of arginine mimetic residue into peptides for recognition of double stranded nucleic acid structure: Binding and aggregation studies

Abstract

An arginine mimetic, featuring a guanidiniocarbonypyrrol as artificial anion binding site (GCP), was introduced into short peptides to study their binding and aggregation with double stranded DNA and RNA. While the incorporation of this GCP modification did not significantly change the overall binding affinity for DNA/RNA, their interactions were more sensitive with respect to the type of polynucleotides. Peptide 4, with four GCP modifications, exhibited amazing fluorescent selectivity for AU- and (to a lesser extent) AT- sequences. GC-containing DNA showed much lower response. Additionally, exclusively tri-GCP modified peptide 3 showed intriguing exciton-coupled bisignate ICD bands for all studied DNA/RNA which suggested that a well-defined GCP-dimer bound into DNA/RNA groove..