Oligomeric assemblies are thought to play a common role in the activity of a variety of antimicrobial peptides, particularly those acting on the bacterial membrane. In an aim to elucidate its mechanism of action, the β-sheet antimicrobial peptide originated from Baboons (BTD-2) was chemically synthesized in both L-and D-forms. Interestingly, racemic protein crystallography of BTD-2 revealed a novel anti-parallel trimeric form (Figure ). This novel supramolecular discovery is fibril-like and is postulated to have critical roles in membrane disruption. In another example, melittin is an α-helical antimicrobial peptide isolated from honeybee venom which is known to exert its activity by disrupting the bacterial cell membrane. The tetrameric assembly observed in the solution state is also present in ). All structures were modelled in CCP4MG with data obtained from the Protein Data Bank. a Total amino acid length of synthetic protein enantiomer, b crystallized from monoolein lipidic cubic phase, c rystallized from racemic lipids d data unavailable, e residues in D-protein enantiomer, f 73 residues + oligosaccharide, g Not reported/deposited.