Maeda N, Takagi K, Tamiya N, Chen Y M, Lee C Y
Biochem J. 1974 Aug;141(2):383-7. doi: 10.1042/bj1410383.
A weakly neurotoxic component (Ls-III) was isolated by CM-cellulose column chromatography from the venom of a sea snake Laticauda semifasciata. The content of component LsIII was about 10-20% of the venom as determined by u.v. absorption at 280nm. Component LsIII was homogeneous on rechromatography and disc electrophoresis, and its molecular weight was shown to be 7100 by ultracentrifugation and 7300 by sodium dodecyl sulphate-polyacrylamide-gel disc electrophoresis. The isoelectric point of component LsIII was pH7.2. Component LsIII consisted of 66 amino acid residues including 10 half-cystine residues. The LD(50) of component LsIII by intramuscular injection was 1.24mug/g body wt. for mice and 0.45mug/g for baby chicks, which is about eight to ten times less toxic than erabutoxins a, b and c, all of which are contained in the same venom. Experiments with three isolated muscle preparations from different species indicated that component LsIII was a post-synaptically acting toxin, the action of which was easily reversed by washing.
通过CM - 纤维素柱色谱法从半环扁尾海蛇毒液中分离出一种弱神经毒性成分（Ls - III）。根据280nm处的紫外吸收测定，成分LsIII的含量约为毒液的10 - 20%。成分LsIII在再色谱分析和圆盘电泳中呈均一性，通过超速离心法测得其分子量为7100，通过十二烷基硫酸钠 - 聚丙烯酰胺凝胶圆盘电泳测得为7300。成分LsIII的等电点为pH7.2。成分LsIII由66个氨基酸残基组成，其中包括10个半胱氨酸残基。通过肌肉注射，成分LsIII对小鼠的半数致死量（LD50）为1.24μg/g体重，对雏鸡为0.45μg/g，其毒性比同一种毒液中所含的 erabutoxins a、b和c低约八至十倍。对来自不同物种的三种分离肌肉制剂进行的实验表明，成分LsIII是一种突触后作用毒素，通过冲洗其作用很容易逆转。
