Studies on the modification of arginine, lysine and tryptophan residues in cecropin D from the Chinese oak silk moth, Antheraea pernyI

The tryptophan, arginine and lysine residues of cecropin D were modified by N-bromosuccinimide (NBS), 1, 2-CYCLOHEXANEDIONE (CHD) and maleic little relationship to the antibacterial activity of the peptide against Escherichiacoli D31, but that the arginine and lysine residues were important to the cecropin D resulted in a total loss of its antibacterial activity against E. coli D31. When the arginine and lysine residues were each regenerated from the modified structures the antibacterial acivity of cecropin D was recovered. These results suggest that the antibacterial activity of cecropin D is related to the charge in the molecule. Ouchterlony double immunodiffusion showed that the antigenic determinant of cecropin D is closely connected with the arginine residues in the peptide.