Nanomolar Affinity Host-Dye Reporter Pairs from Fluorescently Labeled Oligoarginine Peptides and p-Sulfonatocalix[4]arene.

ABSTRACT: Oligoarginine peptides are of interest as cell-penetrating peptides (CPPs) and play important roles in gene regulation and immune response. Complexation of oligoarginine peptides by the supramolecular host p-sulfonatocalix[4]arene (CX4) is well-established and has led to the use of CX4 derivatives as effective counterion activators for arginine-rich CPPs and to the application of CX4 in peptide sensing. Herein, a systematic binding study between oligoarginine peptides with CX4 is reported. The results show that the binding affinity increases with increasing peptide length from ≈10⁴M^-1 for the peptide H-Arg-Arg-OH to nanomolar affinities for peptides with more than four arginine residues. Within the series, C-terminal carboxamides show higher affinities than the respe

SUBMITTER: Pramanik A 

PROVIDER: S-EPMC12781158 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature