The present invention relates to a method of forming a peptide of Formula (I) (P1-Xaa1-Xaa2-P2) by ligating a first peptide of Formula (II) (P1-Xaa1-X—R, wherein X is O or S) to a second peptide of Formula (III) (Xaa1-Xaa2-P2) by enzymatically cleaving the bond between “Asx” and “X” in the first peptide of Formula (II) and ligating the fragment P1-Asx of the first peptide to the second peptide of Formula (III), wherein the enzymatic cleavage and ligation reaction is catalyzed by butelase 1 (SEQ ID NO: 1) and the peptide of Formula (I) is a depsipeptide, preferably a thiodepsipeptide. Further encompassed are peptides and dendrimeric peptide assemblies prepared using the presently disclosed method, as well as use of the dendrimeric peptide assemblies as a vaccine, medicament, or diagnostic agent, particularly as an antimicrobial agent.