A new class of neurotoxin from wasp venom slows inactivation of sodium current
A new class of neurotoxin from wasp venom slows inactivation of sodium current
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来自黄蜂毒液的一类新型神经毒素可减缓钠电流的失活
DOI：
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发表时间：
2000
影响因子：
3.4
通讯作者：
N. Kawai
中科院分区：
文献类型：
--
作者：
Y. Sahara;Masamichi Gotoh;K. Konno;A. Miwa;H. Tsubokawa;H. Robinson;N. Kawai
研究了从孤蜂毒液中分离的新毒素--α-PMTX对龙虾足和大鼠三叉神经节（TG）神经元神经肌肉突触的作用。来自突触前轴突终末和支配龙虾腿肌肉的成对细胞内记录显示，α-PMTX在突触前轴突中诱导长的动作电位爆发，这导致促进兴奋性和抑制性突触传递。α-PMTX的作用不同于其他已知的易化突触前毒素，包括海葵毒素和α-蝎毒素，它们改变了Na+电流的快速失活。我们通过大鼠三叉神经元的全细胞记录进一步表征了α-PMTX对Na+通道的作用。我们发现，α-PMTX减缓Na+通道失活过程，而不改变河豚毒素（TTX）敏感性Na+电流的峰值电流-电压关系或激活时间过程，并且α-PMTX对Na+电流失活和失活尾电流的恢复速率具有电压依赖性影响。结果表明，α-PMTX减缓或阻断细胞外表面Na+通道快速失活所需的构象变化。α-PMTX由13个氨基酸组成的简单结构将有利于理解Na+通道蛋白的功能结构。
The effects of α‐pompilidotoxin (α‐PMTX), a new neurotoxin isolated from the venom of a solitary wasp, were studied on the neuromuscular synapses in lobster walking leg and the rat trigeminal ganglion (TG) neurons. Paired intracellular recordings from the presynaptic axon terminals and the innervating lobster leg muscles revealed that α‐PMTX induced long bursts of action potentials in the presynaptic axon, which resulted in facilitated excitatory and inhibitory synaptic transmission. The action of α‐PMTX was distinct from that of other known facilitatory presynaptic toxins, including sea anemone toxins and α‐scorpion toxins, which modify the fast inactivation of Na+ current. We further characterized the action of α‐PMTX on Na+ channels by whole‐cell recordings from rat trigeminal neurons. We found that α‐PMTX slowed the Na+ channels inactivation process without changing the peak current–voltage relationship or the activation time course of tetrodotoxin (TTX)‐sensitive Na+ currents, and that α‐PMTX had voltage‐dependent effects on the rate of recovery from Na+ current inactivation and deactivating tail currents. The results suggest that α‐PMTX slows or blocks conformational changes required for fast inactivation of the Na+ channels on the extracellular surface. The simple structure of α‐PMTX, consisting of 13 amino acids, would be advantageous for understanding the functional architecture of Na+ channel protein.
大鼠脑 IIA 型 Na 通道 α 亚基在体细胞系中的高效表达。
影响因子：
16.2
作者：
West,JW;Scheuer,T;Maechler,L;Catterall,WA
通讯作者：
Catterall,WA
DOI：
10.1073/pnas.86.24.10161
发表时间：
1989-12-01
影响因子：
11.1
作者：
THOMSEN, WJ;CATTERALL, WA
通讯作者：
CATTERALL, WA
DOI：
10.1073/pnas.77.11.6496
发表时间：
1980-11
影响因子：
11.1
作者：
J. Fontecilla-Camps;R. Almassy;F. L. Suddath;D. Watt;C. Bugg
通讯作者：
J. Fontecilla-Camps;R. Almassy;F. L. Suddath;D. Watt;C. Bugg