MicroO-conotoxin MrVIA inhibits mammalian sodium channels, but not through site I.
MicroO-conotoxin MrVIA inhibits mammalian sodium channels, but not through site I.
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MicroO-芋螺毒素 MrVIA 抑制哺乳动物钠通道，但不是通过位点 I。
DOI：
10.1152/jn.1996.76.3.1423
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Olivera,BM
中科院分区：
文献类型：
--
作者：
Terlau,H;Stocker,M;Shon,KJ;McIntosh,JM;Olivera,BM
1.一种来自捕螺物种真姬菇毒液的31个氨基酸的肽，微O-芋螺毒素MrVIA，通过一种不同于石房蛤毒素、河豚毒素或μ-芋螺毒素的新机制抑制哺乳动物电压门控钠通道。2. MicroO-芋螺毒素MrVIA阻断非洲爪蟾卵母细胞中表达的大鼠脑II型钠通道（IC 50约为200 nM，希尔系数约为1.6 +/- 0.2，平均值+/- SE）。通道激活/失活动力学和电流-电压关系未受干扰。3. MicroO-芋螺毒素MrVIA不会引起在表达大鼠脑II型钠通道的爪蟾卵母细胞中测量的钠电流的阶段性或使用依赖性抑制，但将这些钠通道的稳态可用性转移到更超极化的电位。4.微量O-芋螺毒素MrVIA抑制培养大鼠海马细胞钠通道电导的快速失活。抑制作用可迅速逆转。5. MicroO-芋螺毒素MrVIA不取代特定的[3 H]石房蛤毒素与大鼠脑或Electrophorus电器官部位的结合，表明通过与部位I不同的结合部位介导的抑制作用。
1. A 31-amino-acid peptide from the venom of the snail-hunting species Conus marmoreus, microO-conotoxin MrVIA, inhibits mammalian voltage-gated sodium channels through a novel mechanism distinct from saxitoxin, tetrodotoxin, or mu-conotoxin. 2. MicroO-Conotoxin MrVIA blocks rat brain type II sodium channels expressed in Xenopus oocytes (IC50 approximately 200 nM, Hill coefficient approximately 1.6 +/- 0.2, mean +/- SE). Channel activation/inactivation kinetics and current-voltage relationships were unperturbed. 3. MicroO-Conotoxin MrVIA does not cause phasic or use-dependent inhibition of sodium currents measured in Xenopus oocytes expressing rat brain type II sodium channels, but shifts the steady-state availability of these sodium channels to more hyperpolarized potentials. 4. MicroO-Conotoxin MrVIA inhibited rapidly inactivating sodium channel conductance in rat hippocampal cells in culture. The inhibition was rapidly reversible. 5. MicroO-Conotoxin MrVIA does not displace specific [3H]saxitoxin binding to either rat brain or Electrophorus electric organ sites, indicating inhibitory effects mediated through a binding site distinct from site I.