The purification and amino acid sequences of four Tx2 neurotoxins from the venom of the Brazilian ‘armed’ spider Phoneutria nigriventer (Keys)

• Published in: FEBS letters Vol. 310; no. 2; pp. 153 - 156
• Main Authors: Cordeiro, Marta do Nascimento, Diniz, Carlos Ribeiro, do Carmo Valentim, Ana, von Eickstedt, Vera Regina D., Gilroy, John, Richardson, Michael
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 28.09.1992; Elsevier
• Subjects: Amino Acid Sequence; Aminoacids, peptides. Hormones. Neuropeptides; Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Chromatography, Gel; Chromatography, High Pressure Liquid; Fundamental and applied biological sciences. Psychology; Guinea Pigs; Ileum - drug effects; In Vitro Techniques; Molecular Sequence Data; Muscle, Smooth - drug effects; Neuropeptides - chemistry; Neuropeptides - isolation & purification; Neuropeptides - toxicity; Neurotoxin; Neurotoxins - chemistry; Neurotoxins - isolation & purification; Neurotoxins - toxicity; Phoneutria nigriventer; Proteins; Sequence Homology; Sequence Homology, Nucleic Acid; Spider venom; Spider Venoms - chemistry; Spider Venoms - toxicity; Amino acid sequence; Phoneutria nigriventer; Spider venom; Neurotoxin; Purification; Toxicity; Rodentia; Sequence alignment; Arachnida; Vertebrata; Mammalia; Mouse; Arthropoda; Venom; Invertebrata; Aminoacid sequence
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(92)81318-G

Four neurotoxic polypeptides (Tx2.1, Txt2-5, Tx2-6 and Tx2-9) were purified from the venom of the South American ‘armed’ spider Phoneutria nigriventer (Keys) by gel filtration and reverse phase FPLC and HPLC. These cysteine-rich polypeptides exhibited different levels of neurotoxicity in mice after intracerebroventricular injection. Tx2-1, Tx2-5 and Tx2-6 caused spastic paralysis and death, but the less toxic Tx2-9 produced only tail erection and scratching. The molecular weights of the polypeptides as determined by desorption mass spectroscoopy were 5838.8 for Tx2-1, 5116.6 (Tx2-5), 5291.3 (Tx2-6) and 3742.1 (Tx2-9). The complete amino acid sequences of the neurotoxins were determined by automated Edman degradation and by manual DABITC-PITC microseqeunce analysis of peptides obtained after digestions with various proteases. The amino acid sequences of Tx2-1 (53 residues), Tx2-5 (48 residues) and Tx2-6 (48 residues) were homologous, but had only limited similarities to the less toxic Tx2-9 (32 residues). All four polypeptides had varying sequence identities with other neurotoxins from different spider species and biologically active peptides from scorpions, a sea snail and seeds of Mirabilis jalapa.