RESUMO
Venom of the Mexican red knee tarantula (Brachypelma smithii) was fractionated by gel filtration over Sephadex G-50 Fine. Small polypeptides present in the second and third peaks were subfractionated by cation exchange and reversed-phase FPLC. One major, basic protein was isolated and sequenced from each G-50 fraction using a gas-phase protein sequencer. Primary structures were completed and confirmed using tandem mass spectrometry and carboxypeptidase digestions. Protein 1 contains 39 residues, including six cysteine residues in three disulfide bonds. It is identical to one of the isoforms of ESTX from the venom of the tarantula Eurypelma californicum. Brachypelma smithii Protein 5 contains 34 residues, including six cysteine residues in three disulfide bonds. Disulfide bond assignments for both proteins are provided. Protein 5 shows most similarity with toxin Tx2-9 from the Brazilian 'armed' spider, but only displays 41% sequence identity. Similarities with other proteins are lower. Proteins 1 and 5 appear unrelated to each other.
Assuntos
Venenos de Aranha/química , Alquilação , Sequência de Aminoácidos , Aminoácidos/análise , Animais , Fracionamento Químico , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Dissulfetos/química , Espectrometria de Massas , Dados de Sequência Molecular , Peso Molecular , Padrões de Referência , Especificidade da Espécie , Venenos de Aranha/isolamento & purificação , AranhasRESUMO
1. Elution profiles of 11 coral snake venoms, including those of Micrurus albicinctus, M. corallinus, M. frontalis altirostris, M. f. brasiliensis, M. f. frontalis, M. fulvius fulvius, M. ibiboboca, M. lemniscatus ssp., M. rondonianus, M. spixii spixii and M. surinamensis surinamensis, were compared using high performance gel filtration and reverse phase media. 2. Micrurus venom profiles were compared with those of "outgroup" taxa Bothrops moojeni, Naja naja kaouthia and Bungarus multicinctus. 3. Purified elapid venom constituents were also chromatographed under identical conditions in order to suggest possible identities of Micrurus venom constituents. 4. Masses of various components were confirmed by mass spectrometry. 5. Phospholipase constituents in three venoms were positively identified based on their reverse phase chromatograms. 6. Venoms of M. rondonianus and M. s. surinamensis are shown to be significantly different in their peptide composition from other Micrurus venoms.