Decoralin, a novel linear cationic α-helical peptide from the venom of the solitary eumenine wasp Oreumenes decoratus

• DOI: 10.1016/j.peptides.2007.09.017
• Publication Date: 2007-10-02T07:31:00Z
• Authors: Katsuhiro Konno; Marisa Rangel; Joacir Stolarz Ol...; Marcia Perez dos ...; Renato Fontana; Izaura Yoshico Hi...; Izumi Hide; Yoshihiro Nakata; Kanami Mori; Marii Kawano; Hiroyuki Fuchino; Setsuko Sekita; João Ruggiero Neto
• Keywords: 0301 basic medicine; 1303 Biochemistry; antimicrobial and leishmanicidal; Wasps; 2804 Cellular and Molecular Neuroscience; amphipathic alpha-helix structure; Wasp Venoms; Cationic linear α-helical peptide; In Vitro Techniques; Hemolysis; solitary wasp venom; Cell Degranulation; Protein Structure, Secondary; Antimicrobial and leishmanicidal activity; Mice; 03 medical and health sciences; Animals; Humans; Solitary wasp venom; Amino Acid Sequence; Mast Cells; decoralin; Bacteria; activity; Circular Dichroism; 1314 Physiology; 540; 1310 Endocrinology; cationic linear alpha-helical peptide; Rats; Decoralin; Amphipathic α-helix structure; Oligopeptides; Antimicrobial Cationic Peptides

A novel peptide, decoralin, was isolated from the venom of the solitary eumenine wasp Oreumenes decoratus. Its sequence, Ser-Leu-Leu-Ser-Leu-Ile-Arg-Lys-Leu-Ile-Thr, was determined by Edman degradation and corroborated by solid-phase synthesis. This sequence has the characteristic features of linear cationic alpha-helical peptides; rich in hydrophobic and basic amino acids with no disulfide bond, and accordingly, it can be predicted to adopt an amphipathic alpha-helix secondary structure. In fact, the CD spectra of decoralin in the presence of TFE or SDS showed a high alpha-helical conformation content. In a biological evaluation, decoralin exhibited a significant broad-spectrum antimicrobial activity, and moderate mast cell degranulation and leishmanicidal activities, but showed virtually no hemolytic activity. A synthetic analog with C-terminal amidation showed a much more potent activity in all the biological assays.