title: Primary structures of two proteins from the venom of the Mexican red knee tarantula (Brachypelma smithii).
abstract: 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.
authors: Department of Molecular Biology, University of Wyoming, Laramie 82071.
authors: I I
authors: II
authors: Kaiser
authors: P R
authors: PR
authors: Griffin
authors: S D
authors: SD
authors: Aird
authors: S
authors: S
authors: Hudiburg
authors: J
authors: J
authors: Shabanowitz
authors: B
authors: B
authors: Francis
authors: T R
authors: TR
authors: John
authors: D F
authors: DF
authors: Hunt
authors: G V
authors: GV
authors: Odell
mesh_terms: D000478:Alkylation; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D005591:Chemical Fractionation; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004220:Disulfides / Q000737:chemistry; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012015:Reference Standards; D013045:Species Specificity; D013111:Spider Venoms / Q000737:chemistry* / Q000302:isolation & purification; D013112:Spiders
chemical_list: D000596:Amino Acids; D004220:Disulfides; D013111:Spider Venoms