Lanthionine

Lanthionine is a non proteinogenic amino acid found in peptides of microbial origin. It is a sulfide bridged alanine dimer (HOOC-CH(NH2)-CH2-S-CH2-CH(NH2)-COOH) which is synthesized from cysteine and dehydroalanine by posttranslational modifications of peptides.

Lanthionine is together with unsaturated amino acids a part of lantibiotics (antibiotic polycyclic peptides such as nisin, subtilin, epidermin).