Lactocin S is a complex antimicrobial peptide (bacteriocin) derived from "Lactobacillus sakei", and its synthesis is achieved primarily through two distinct methods: biosynthesis and chemical synthesis. The natural biosynthetic pathway involves the ribosome synthesis of a precursor peptide, which then undergoes extensive post-translational modifications (PTMs) catalyzed by specific enzymes to form the characteristic lanethionine and β-methyllanethionine rings essential for its activity. The other method is chemical synthesis, particularly solid-phase peptide synthesis (SPPS), which has been successfully used to construct linear peptide chains, subsequently introducing strained thioether bridges via controlled chemical cyclization steps.
