well correlated with the hydrophobicity and shorter Ribociclib order elution times of the respective peptides (see Table 1). The erythrocytes membranes show a zwitterionic character (Yeaman and Yount, 2003), and peptides with a lower charge and higher hydrophobicity present a stronger interaction with this type of membrane (de Souza et al., 2010). The ability of the peptides to induce mast cells degranulation was assayed in vitro in PT18 cells and RBL-2H3 cells, by the measurement of the enzyme β-hexosaminidase released. As shown in Fig. 8A, all the new peptides were able to induce mild degranulation in connective tissue-type mast cells with equivalent potencies and dose-dependent, selleck inhibitor similarly to Eumenitin, and weaker than mastoparan ( Konno et al., 2006). On the other hand, in mucosal-type mast cells EMP-ER and EMP-EF,
which are similar to EMP-AF, exhibited more intense mast cell degranulation than eumenitin-R and eumenitin-F, which are highly homologous to eumenitin ( Fig. 8B). The results of the leishmanicidal assay are summarized in Table 5. For comparison, eumenitin and EMP-AF were also tested. Most peptides showed an activity, but only moderately. It is noteworthy that the eumenitin series (C-terminal free) are weaker than the EMP series (C-terminal amide). This is similar to our previous results of decoralin (C-terminal free) vs. decoralin-NH2 (C-terminal amide) ( Konno et al., 2007). In the present study,
we have purified four
ar cationic α-helical peptides from two species of the eumenine solitary wasps, E. rubrofemoratus and E. fraterculus, and characterized them both chemically and biologically. Of these, eumenitin-R and eumenitin-F are highly homologous to eumenitin, whereas the others, eumenine of mastoparan-ER (EMP-ER) and eumenine-mastoparan-EF (EMP-EF), are similar to EMP-AF, and thus, can be classified into mastoparan peptides. These results suggested that these types of peptide are commonly and widely distributed in the eumenine wasp venoms. All these peptides and anoplin present the following common interesting physicochemical and biological features: short chain length – 10 to 15 residues long, polycationic character, they assume α-helical conformation upon contact with membrane mimetic environments, and they are antimicrobial, hemolytic and mast cell degranulators at various levels. Conformational and pore-forming activity of these new peptides were investigated in asolectin bilayers, which due to its anionic character mimic the cytoplasmic membrane of bacteria. This phospholipid, whose approximate composition is 23.5% phosphatidylcholine, 20% phosphatidylethanolamine, and 14% inositol phosphatides (other components are 39.