Halogenated Tryptophans Improve Integrin αVβ6 Affinity of Cyclic RGD Peptides and Provide Handles for Late-Stage Derivatization.
Selective targeting of integrin αVβ6 is of high relevance for molecular imaging and therapeutic applications, yet ligands combining high affinity with structural and functional versatility remain limited. A structure-activity relationship (SAR) study of the nonapeptide cyclo-(-Asp-Leu-Ala-Phe-d-Pro-NMeLys-Phe-Arg-Gly-)...