Structural and biological characterization of three novel mastoparan peptides from the venom of the neotropical social wasp Protopolybia exigua (Saussure).
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.
Mendes
Maria Anita
MA
CEIS-Department of Biology, IBRC-UNESP (CAT-CEPID/FAPESP), Institute of Immunological Investigations (Millennium Institute-MCT/CNPq), Rio Claro, SP 13506-900, Brazil.
de Souza
Bibiana Monson
BM
Palma
Mario Sergio
MS
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*
D019476:Insect Proteins; D014862:Wasp Venoms