title: Structural and biological characterization of three novel mastoparan peptides from the venom of the neotropical social wasp Protopolybia exigua (Saussure).
abstract: The venom of the Neotropical social wasp Protopolybia exigua(Saussure) was fractionated by RP-HPLC resulting in the elution of 20 fractions. The homogeneity of the preparations were checked out by using ESI-MS analysis and the fractions 15, 17 and 19 (eluted at the most hydrophobic conditions) were enough pure to be sequenced by Edman degradation chemistry, resulting in the following sequences: Protopolybia MPI I-N-W-L-K-L-G-K-K-V-S-A-I-L-NH2 Protopolybia-MP II I-N-W-K-A-I-I-E-A-A-K-Q-A-L-NH2 Protopolybia-MP III I-N-W-L-K-L-G-K-A-V-I-D-A-L-NH2 All the peptides were manually synthesized on-solid phase and functionally characterized. Protopolybia-MP I is a hemolytic mastoparan, probably acting on mast cells by assembling in plasma membrane, resulting in pore formation; meanwhile, the peptides Protopolybia-MP II and -MP III were characterized as a non-hemolytic mast cell degranulator toxins, which apparently act by virtue of their binding to G-protein receptor, activating the mast cell degranulation.
authors.affiliation: CEIS-Department of Biology, IBRC-UNESP (CAT-CEPID/FAPESP), Institute of Immunological Investigations (Millennium Institute-MCT/CNPq), Rio Claro, SP 13506-900, Brazil.
authors.forename: Maria Anita
authors.initials: MA
authors.lastname: Mendes
authors.forename: Bibiana Monson
authors.initials: BM
authors.lastname: de Souza
authors.forename: Mario Sergio
authors.initials: MS
authors.lastname: Palma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015550:Cell Degranulation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000187:drug effects; D066298:In Vitro Techniques; D019476:Insect Proteins / Q000737:chemistry* / Q000494:pharmacology*; D016015:Logistic Models; D008407:Mast Cells / Q000187:drug effects; D015394:Molecular Structure; D051381:Rats; D014862:Wasp Venoms / Q000737:chemistry*
chemical_list: D019476:Insect Proteins; D014862:Wasp Venoms