Talbot J C, Faucon J F, Dufourcq J
Centre de Recherche Paul Pascal, C.N.R.S., Domaine Universitaire, Talence, France.
Eur Biophys J. 1987;15(3):147-57. doi: 10.1007/BF00263679.
Melittin is known to self-associate as tetramers in solutions of high ionic strength. Here, an N-bromosuccinimide oxidized-Trp19 melittin is prepared. This derivative can act as an acceptor of the fluorescence of native melittin and is used in order to observe a possible self-association of melittin in phospholipid bilayers. Resonance energy transfer was shown to occur in solutions of high ionic strength, showing that oxidized melittin can associate with native melittin. In phospholipid bilayers, no association is detected in the absence of NaCl. In its presence, an equilibrium between monomeric melittin and oligomeric species is observed. These species are not dimers, but any other degree of association may account for our experimental results. Significant differences in characteristic transfer efficiency reveal differences in the structure of these oligomers according to the length or state of phospholipids (fluid or at the transition temperature). These bound complexes are also different from the soluble hetero-oligomer. Some models of bound complexes are proposed which may explain the leakage and the further disruption of vesicles or cells induced by melittin.
已知蜂毒素在高离子强度溶液中会自缔合形成四聚体。在此，制备了一种N-溴代琥珀酰亚胺氧化的Trp19蜂毒素。该衍生物可作为天然蜂毒素荧光的受体，用于观察蜂毒素在磷脂双层中可能的自缔合。结果表明，在高离子强度溶液中会发生共振能量转移，这表明氧化的蜂毒素可与天然蜂毒素缔合。在磷脂双层中，在没有NaCl的情况下未检测到缔合。在有NaCl存在的情况下，观察到单体蜂毒素与寡聚体之间的平衡。这些寡聚体不是二聚体，但任何其他缔合程度都可能解释我们的实验结果。特征转移效率的显著差异揭示了根据磷脂的长度或状态（流体状态或处于转变温度）这些寡聚体结构的差异。这些结合复合物也不同于可溶性杂合寡聚体。提出了一些结合复合物模型，这些模型可能解释蜂毒素诱导的囊泡或细胞泄漏及进一步破坏。
