BmTx3B, a novel scorpion toxin from Buthus martensi Karsch, inhibits delayed rectifier Potassium current in rat hippocampal neurons  

东亚钳蝎中新分离的毒素BmTx3B抑制大鼠海马神经元延迟整流性钾电流(英文)

作　　者：李明华[1] 王跃丰[2] 陈学勤[1] 张乃霞[2] 吴厚铭[2] 胡国渊[1] 

机构地区：[1]中科院上海生命科学研究院上海药物研究所新药研究国家重点实验室,上海201203 [2]中科院上海有机化学研究所生命有机化学国家重点实验室,上海200032

出　　处：《Acta Pharmacologica Sinica》2003年第10期1016-1020,1062,共6页中国药理学报（英文版）

摘　　要：AIM: To examine the effect of BmTx3B, a novel short-chain peptide isolated from the venom of Asian scorpion Buthus martensi Karsch, on voltage-gated potassium channels. METHODS: Two types of voltage-dependent potassium currents were recorded from dissociated hippocampal neurons of neonatal rat in whole-cell voltageclamp mode, and separated based upon their kinetic properties. RESULTS: BmTx3B(10-100μmol/L) selectively inhibited the delayed rectifier potassium current(I_K), without affecting the fast transient potassium current(I_A).The inhibition of the peptide on I_K was reversible, concentration-dependent and voltage-independent. BmTx3B did not affect the steady-state activation and inactivation kinetics of the current. CONCLUSION: The short-chain scorpion peptide BmTx3B selectively blocked the delayed rectifier potassium channel.目的:研究从东亚钳蝎毒素中新分离的短肽BmTx3B对电压门控性钾通道的作用。方法:在酶解打散的新生大鼠海马细胞,采用全细胞电压箝位方式记录,并根据动力学特性分离二种电压依赖性钾电流。结果:BmTx3B(10-100μmol/L)选择地抑制延迟整流性钾电流(I_k),不影响瞬时性快钾电流(I_A),此抑制作用是可逆的,呈现浓度依赖性,但无电压依赖性,BmTx3B对延迟整流性钾电流的稳态激活和稳态失活的动力学特性无影响。结论:蝎毒短肽BmTx3B选择地抑制海马神经元延迟整流性钾通道。

关 键 词：BmTx3B Buthus martensi Karsch HIPPOCAMPUS potassium channels scorpion venom 

分 类 号：R96[医药卫生—药理学]