Cyclization of Peptides by using Selenolanthionine Bridges

Selenocysteine does the job: Lanthionine bridges are important structural elements in naturally occurring lantibiotics. They can be engineered into peptides to increase biological activity and metabolic stability. Macrocyclization of peptides by intramolecular thiolation of cysteine is often difficult but can be achieved by replacing cysteine with the more reactive isosteric selenocysteine amino acid.