CHARACTERIZATION OF NEUROTOXIC CONSTITUENTS OF CONUS-GEOGRAPHUS(L) VENOM
CHARACTERIZATION OF NEUROTOXIC CONSTITUENTS OF CONUS-GEOGRAPHUS(L) VENOM
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DOI：
10.1016/0024-3205(77)90156-4
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发表时间：
1977-01-01
期刊：
影响因子：
6.1
通讯作者：
QUINN, RJ
中科院分区：
文献类型：
--
作者：
SPENCE, I;GILLESSEN, D;QUINN, RJ
海洋腹足动物Conus geographus（L.）分离为3种致死成分，并研究了它们在哺乳动物神经肌肉接头处的作用。蛇毒经SephadexG-50柱层析得到1个毒性组分，经SP-Sephadex离子交换层析得到3个毒性组分。通过渗滤和Sephadex G-15层析分别纯化这些组分，得到毒素I、II和III。浓度大于5 μ g/ml的毒素I和II降低终板电位[epp]和微型终板电位[mepp]的幅度;毒素I还阻断由卡巴胆碱产生的肌纤维的去极化;两种毒素都不影响肌纤维中动作电位的产生。浓度大于5 μ g/ml的毒素III快速且可逆地阻断肌纤维中动作电位的产生;它对静息膜电位和epp或mepp的振幅没有影响。它还缓慢地阻断从离体坐骨神经记录的复合动作电位，但这在实验中是不可逆的。该毒素阻断动作电位的速率通过刺激制剂而增加。毒素III可能通过阻断活动期间Na的向内运动而起作用。毒素III似乎是十九碳或二十碳肽，可能在N-末端位置具有胱氨酸残基。
The crude venom of the marine gastropod Conus geographus (L.) was separated into 3 lethal constituents and their actions at the mammalian neuromuscular junction examined. Chromatography of the venom on Sephadex G-50 gave 1 toxic fraction, which was resolved by ion exchange chromatography on SP-Sephadex into 3 toxic components. These components were individually purified by diafiltration and Sephadex G-15 chromatography to give Toxins I, II and III. Toxins I and II in concentrations greater than 5 .mu.g/ml reduced the amplitude of end-plate potentials [epp] and miniature end-plate potentials [mepp]; Toxin I also blocked the depolarization of muscle fibers produced by carbachol; neither toxin affected the generation of action potentials in muscle fibers. Toxin III in concentrations greater than 5 .mu.g/ml rapidly and reversibly blocked the generation of action potentials in muscle fibers; it had no effect on resting membrane potential nor on the amplitude of epp or mepp. It also slowly blocked the compound action potential recorded from isolated sciatic nerves but this was not reversible in the experiments. The rate at which this toxin blocked action potentials was increased by stimulation of the preparation. Toxin III probably acts by blocking the inward movement of Na during activity. Toxin III appeared to be a nonadeca or eicosa peptide possibly having a cystine residue in the N-terminal position.