RESUMO
Two novel inflammatory peptides were isolated from the venom of the social wasp Polybia paulista. They had their molecular masses determined by ESI-MS and their primary sequences were elucidated by Edman degradation chemistry as: Polybia-MPI: I D W K K L L D A A K Q I L-NH2 (1654.09 Da), Polybia-CP: I L G T I L G L L K S L-NH2 (1239.73 Da). Both peptides were functionally characterized by using Wistar rat cells. Polybia-MPI is a mast cell lytic peptide, which causes no hemolysis to rat erythrocytes and presents chemotaxis for polymorphonucleated leukocytes (PMNL) and with potent antimicrobial action both against Gram-positive and Gram-negative bacteria. Polybia-CP was characterized as a chemotactic peptide for PMNL cells, presenting antimicrobial action against Gram-positive bacteria, but causing no hemolysis to rat erythrocytes and no mast cell degranulation activity at physiological concentrations.
Assuntos
Antibacterianos/química , Peptídeos/química , Venenos de Vespas/química , Vespas/química , Animais , Antibacterianos/toxicidade , Degranulação Celular/efeitos dos fármacos , Degranulação Celular/fisiologia , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Células Cultivadas , Bactérias Gram-Positivas/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Hemólise/fisiologia , Leucócitos/citologia , Leucócitos/fisiologia , Mastócitos/citologia , Mastócitos/fisiologia , Peptídeos/toxicidade , Ratos , Ratos Wistar , Venenos de Vespas/toxicidadeRESUMO
Brazil has many species of spiders belonging to Araneidae family however, very little is known about the composition, chemical structure and mechanisms of action of the main venom components of these spiders. The main objective of this work was to isolate and to perform the chemical characterization of a novel beta-carboline toxin from the venom of the spider Parawixia bistriata, a typical species of the Brazilian 'cerrado'. The toxin was purified by RP-HPLC and structurally elucidated by using a combination of different spectroscopic techniques (UV, ESI-MS/MS and 1H NMR), which permitted the assignment of the molecular structure of a novel spider venom toxin, identified as 1-4-guanidinobutoxy-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline, and referred to here as PwTx-II. This compound is toxic to insects (LD50 = 12+/-3 etag/mg honeybee), neurotoxic, convulsive and lethal to rats (LD50 = 9.75 mg/kg of male Wistar rat).