Warning - really scientific stuff, no dumbing this down
Structural and Functional Characterization of a Multifunctional Alanine-Rich Peptide Analogue from Pleuronectes americanus
For melittin, a promiscuous peptide from Apis mellifera [76], it was demonstrated that mutations of arginine and lysine residues changed the total activity, with a major effect on toxicity to mammalian cells, reducing 8-fold the activity of the peptide after modification [77].
http://www.plosone.org/article/info%...l.pone.0047047