S. Kobayashi et al., Bacteria-selective synergism between the antimicrobial peptides alpha-helical magainin 2 and cyclic beta-sheet tachyplesin I: Toward cocktail therapy, BIOCHEM, 40(48), 2001, pp. 14330-14335
Magainin 2 and tachyplesin I (T-SS) are membrane-permeabilizing antimicrobi
al peptides discovered from frog skin and horseshoe crab hemolymph, respect
ively. They are classified into different secondary structural classes. i.e
.. a-helix and cyclic beta -sheet, respectively. We found that F5W-magainin
2 (MG2) and T-SS exhibited marked synergistic effects against Gram-negativ
e and Grain-positive bacteria without enhancing hemolytic activity as a mea
sure of toxicity. Dye release experiments using liposomes suggested that th
e selective synergism is mainly due to anionic phospholipid-specific synerg
ism in membrane permeabilization. Furthermore, the cyclic structure of T-SS
was found to be necessary for synergism because a linear analogue of T-SS
did not show good synergism with MG2. These novel observations suggested th
e possibility of the development of cocktail therapeutic regimens using com
binations of antimicrobial peptides.