Figure 1.

EDC/sulfo–NHS (1-ethyl-3-[3-dimethylaminopropyl] carbodiimide/N-hydroxysulfosuccinimide) cross-linking reaction. Schematic illustration and chemical reaction of the one-pot and in situ LDLK12 (Ac-LDLKLDLKLDLK-CONH₂) cross-linking based on EDC/sulfo–NHS coupling: (I) LDLK12, (II) O-acylisourea intermediate LDLK12 peptide, (III) sulfo–NHS-modified LDLK12 peptide, and (IV) EDC/sulfo–NHS cross-linked LDLK12 peptides. In the schematic representation of the amide bond formation, the LDLK12 peptide is shown in black, the carboxyl group is shown in blue, EDC is shown in magenta, and sulfo–NHS is shown in light green.