Electrophysiological characterization and molecular identification of the Phoneutria nigriventer peptide toxin PnTx2‐6 1

FEBS Letters

Matavel, Alessandra³  Diniz, Carlos R³  Cordeiro, Marta N²  Penaforte, Claudia L³  Beirão, Paulo S.L³  Prado, Vânia F³  Cruz, Jader S³  Araújo, Demétrius A.M⁴  Kalapothakis, Evanguedes¹ 

[1] Department of Pharmacology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil;Fundação Ezequiel Dias, Belo Horizonte, MG, Brazil;Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Caixa Postal 486, 30161-970 Belo Horizonte, MG, Brazil;Department of Molecular Biology, Universidade Federal da Paraı́ba, João Pessoa, PB, Brazil

关键词: PnTx2-6;    Spider toxin;    Peptide toxin;    Neurotoxin;    Sodium channel;    Phoneutria nigriventer;   

DOI  :  10.1016/S0014-5793(02)02988-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A cDNA with 403 nucleotides encoding the precursor of the toxin PnTx2-6 was cloned and sequenced. Subsequent analysis revealed that the precursor begins with a signal peptide and a glutamate-rich propeptide. The succeeding peptide confirmed the reported sequence of PnTx2-6. The purified toxin exerted complex effects on Na⁺ current of frog skeletal muscle. There was a marked decrease of the inactivation kinetics, and a shift to hyperpolarizing potentials of both the Na⁺ conductance and the steady-state inactivation voltage dependences, along with a reduction of the current amplitude. The concentration dependence of the modified current suggests a K _D of 0.8 μM for the toxin–channel complex.

【 授权许可】

Unknown