Design, Synthesis, and Validation of a Branched Flexible Linker for Bioactive Peptides

A branched flexible linker that incorporates a fluorescent dansyl moiety was synthesized and used to connect two high affinity NDP-α-MSH ligands or two low affinity MSH(4) ligands. The linker was incorporated into the conjugate by solid-phase synthesis. In vitro biological evaluations showed that potency of binding to the human melanocortin 4 receptor was not diminished for linker−ligand combinations relative to the corresponding ligand alone.