RESUMO
Comprehensive LC-MS and MS/MS analysis of the crude venom extract from the solitary eumenine wasp Eumenes micado revealed the component profile of this venom mostly consisted of small peptides. The major peptide components, eumenine mastoparan-EM1 (EMP-EM1: LKLMGIVKKVLGAL-NH2) and eumenine mastoparan-EM2 (EMP-EM2: LKLLGIVKKVLGAI-NH2), were purified and characterized by the conventional method. The sequences of these new peptides are homologous to mastoparans, the mast cell degranulating peptides from social wasp venoms; they are 14 amino acid residues in length, rich in hydrophobic and basic amino acids, and C-terminal amidated. Accordingly, these new peptides can belong to mastoparan peptides (in other words, linear cationic a-helical peptides). Indeed, the CD spectra of these new peptides showed predominantly a-helix conformation in TFE and SDS. In biological evaluation, both peptides exhibited potent antibacterial activity, moderate degranulation activity from rat peritoneal mast cells, and significant leishmanicidal activity, while they showed virtually no hemolytic activity on human or mouse erythrocytes. These results indicated that EMP-EM peptides rather strongly associated with bacterial cell membranes rather than mammalian cell membranes
RESUMO
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.
Assuntos
Oligopeptídeos/química , Oligopeptídeos/isolamento & purificação , Venenos de Vespas/química , Sequência de Aminoácidos , Animais , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias/efeitos dos fármacos , Degranulação Celular/efeitos dos fármacos , Dicroísmo Circular , Hemólise/efeitos dos fármacos , Humanos , Técnicas In Vitro , Mastócitos/efeitos dos fármacos , Mastócitos/fisiologia , Camundongos , Oligopeptídeos/genética , Oligopeptídeos/farmacologia , Estrutura Secundária de Proteína , Ratos , Venenos de Vespas/genética , Venenos de Vespas/farmacologia , Vespas/química , Vespas/genéticaRESUMO
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 á-helical peptides; rich in hydrophobic and basic amino acids with no disulfide bond, and accordingly, it can be predicted to adopt an amphipathic á-helix secondary structure. In fact, the CD spectra of decoralin in the presence of TFE or SDS showed a high á-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.
Assuntos
Animais , Mordeduras e Picadas de Insetos , Vespas/classificaçãoRESUMO
A novel antimicrobial peptide, eumenitin, was isolated from the venom of the solitary eumenine wasp Eumenes rubronotatus. The sequence of eumenitin, Leu-Asn-Leu-Lys-Gly-Ile-Phe-Lys-Lys-Val-Ala-Ser-Leu-Leu-Thr, was mostly analyzed by mass spectrometry together with Edman degradation, and corroborated by solid-phase synthesis. This peptide has characteristic features of cationic linear alpha-helical antimicrobial peptides, and therefore, can be predicted to adopt an amphipathic alpha-helix secondary structure. In fact, the CD spectra of eumenitin in the presence of TFE or SDS showed a high content of alpha-helical conformation. Eumenitin exhibited inhibitory activity against both Gram-positive and Gram-negative bacteria, and moderately stimulated degranulation from the rat peritoneal mast cells and the RBL-2H3 cells, but showed no hemolytic activity against human erythrocytes. This antimicrobial peptide in the eumenine wasp venom may play a role in preventing potential infection by microorganisms during prey consumption by their larvae.
Assuntos
Antibacterianos/isolamento & purificação , Peptídeos Catiônicos Antimicrobianos/genética , Venenos de Vespas/química , Venenos de Vespas/isolamento & purificação , Sequência de Aminoácidos , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Dicroísmo Circular , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Venenos de Vespas/genética , Venenos de Vespas/farmacologia , VespasRESUMO
A novel antimicrobial peptide, eumenitin, was isolated from the venom of the solitary eumenine wasp Eumenes rubronotatus. The sequence of eumenitin, LeuAsnLeuLysGlyIlePheLysLysValAlaSerLeuLeuThr, was mostly analyzed by mass spectrometry together with Edman degradation, and corroborated by solid-phase synthesis. This peptide has characteristic features of cationic linear á-helical antimicrobial peptides, and therefore, can be predicted to adopt an amphipathic á-helix secondary structure. In fact, the CD spectra of eumenitin in the presence of TFE or SDS showed a high content of á-helical conformation. Eumenitin exhibited inhibitory activity against both Gram-positive and Gram-negative bacteria, and moderately stimulated degranulation from the rat peritoneal mast cells and the RBL-2H3 cells, but showed no hemolytic activity against human erythrocytes. This antimicrobial peptide in the eumenine wasp venom may play a role in preventing potential infection by microorganisms during prey consumption by their larvae.