Exciton coupled circular dichroic studies of self-assembled brevetoxin-porphyrin conjugates in lipid bilayers and polar solvents.
Exciton coupled circular dichroic studies of self-assembled brevetoxin-porphyrin conjugates in lipid bilayers and polar solvents.
复制标题
脂双层和极性溶剂中自组装短尾毒素-卟啉缀合物的激子耦合圆二色性研究。
DOI：
10.1016/s1074-5521(96)90121-0
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发表时间：
1996
影响因子：
--
通讯作者：
Nakanishi,K
中科院分区：
文献类型：
--
作者：
Matile,S;Berova,N;Nakanishi,K
背景：已知与赤潮和贝类中毒有关的Brevetoxins与细胞膜和膜蛋白结合。Brevetoxin B（BTX-B）与神经元钠通道特异性相互作用。我们最近发现，BTX也诱导选择性离子运动通过跨膜BTX self-assemblies.Results的脂质bilayers：我们研究了几个BTX衍生物的自组装阳离子和脂质bilayers的存在和不存在下，使用强大的卟啉发色团作为圆二色性标签。BTX衍生物自组装成管，其在可溶时和插入双层中以形成跨膜孔时都可以与金属结合。根据BTX衍生物的倾向，自聚集（临界“胶束”浓度，CMC），它可能会聚集在溶液中膜插入前，或可能会插入到膜作为一个单体组装pore.Conclusions组装前的膜：在脂质双层的活性BTX-B复合物是一个循环，跨膜自组装体，由反平行对齐的BTX分子，可以介导选择性离子运动通过膜。BTX衍生物之间孔形成机制的差异可能反映在天然BTX变体的孔形成差异中，这可能解释了它们不同水平的毒性。
Background:Brevetoxins, involved in the ‘red tide' as well as shellfish poisoning, are known to bind to cell membranes and membrane proteins. Brevetoxin B (BTX-B) interacts specifically with neuronal sodium channels. We recently found that BTX also induces selective ion movements across lipid bilayers through transmembrane BTX self-assemblies.Results:We examined the self-assembly of several BTX derivatives in the presence and absence of cations and lipid bilayers using the powerful porphyrin chromophores as circular dichroism labels. BTX derivatives self-assemble into tubes, which can bind to metals both when soluble and when inserted into the bilayer to form transmembrane pores. Depending on the tendency of the BTX derivative to self-aggregate (the critical "micelle" concentration, cmc), it may aggregate in solution before membrane insertion, or may insert itself into the membrane as a monomer before assembling the pore.Conclusions:The active BTX-B complex in lipid bilayers is a cyclic, transmembrane self-assembly consisting of antiparallel aligned BTX molecules that can mediate selective ion movement through membranes. The differences in pore formation mechanisms between BTX derivatives may be reflected in differences in pore formation by natural BTX variants, perhaps explaining their varying levels of toxicity.