Structure and biological activities of eumenine mastoparan-AF (EMP-AF), a new mast cell degranulating peptide in the venom of the solitary wasp (Anterhynchium flavomarginatum micado)

A new mast cell degranulating peptide, eumenine mastoparan-AF (EMP-AF), was isolated from the venom of the solitary wasp Anterhynchium flavomarginatum micado, the most common eumenine wasp found in Japan. The structure was an alyzed by FAB-MS/MS together with Edman degradation, which was corroborated by solid-phase synthesis. The sequence of EMP-AF, Ile-Asn-Leu-Leu-Lys-Ile- Ala-Lys-Gly-Ile-lle-Lys-Ser-Leu-NH2, was similar to that of mastoparan, a m ast cell degranulating peptide from a hornet venom; tetradecapeptide with C -terminus amidated and rich in hydrophobic and basic amino acids. In fact, EMP-AF exhibited similar activity to mastoparan in stimulating degranulatio n from rat peritoneal mast cells and RBL-2H3 cells. It also showed signific ant hemolytic activity in human erythrocytes. Therefore, this is the first example that a mast cell degranulating peptide is found in the solitary was p venom. Besides the degranulation and hemolytic activity, EMP-AF also affe cts on neuromuscular transmission in the lobster walking leg preparation. T hree analogs EMP-AF-1 similar to 3 were snythesized and biologically tested together with EMP-AF, resulting in the importance of the C-terminal amide structure for biological activities. (C) 2000 Elsevier Science Ltd. All rig hts reserved.