Zhao J, Kimura S, Imanishi Y
Department of Polymer Chemistry, Kyoto University, Japan.
Biochim Biophys Acta. 1996 Aug 14;1283(1):37-44. doi: 10.1016/0005-2736(96)00071-5.
The membrane-fusion activities of amphiphilic peptides of H-(Leu-Aib-Lys-Aib-Aib-Lys-Aib)n-Ala-N(C18H37)2 (n = 1, P7D and n = 3, P21D) immobilized on liposome were investigated. P7D, which takes a random conformation, induced fusion of DPPC SUV, but P7D immobilized on the DPPC SUV did not show the fusion activity. On the other hand, P21D showed a high activity of membrane fusion either in the free peptide or in the immobilized state. CF-Leakage experiments revealed that the peptides caused a transient perturbation of the membrane structure on binding to the membrane. A lasting and steady perturbation was also caused by P21D embedded in the membrane, which was indicated by EU3+ permeation through the membrane. This type of membrane perturbation was very slight in the case of P7D embedded in the membrane. A conclusion was reached that the different activities in the membrane fusion are based on the transient perturbation in the membrane at the peptide binding to the membrane surface as well as the steady perturbation caused by the peptide embedded in the membrane.
研究了固定在脂质体上的两亲性肽H-(Leu-Aib-Lys-Aib-Aib-Lys-Aib)n-Ala-N(C18H37)2（n = 1时为P7D，n = 3时为P21D）的膜融合活性。呈随机构象的P7D可诱导二棕榈酰磷脂酰胆碱（DPPC）小单层囊泡（SUV）融合，但固定在DPPC SUV上的P7D未表现出融合活性。另一方面，P21D无论是游离肽状态还是固定状态都表现出较高的膜融合活性。荧光素泄漏实验表明，这些肽与膜结合时会引起膜结构的瞬时扰动。嵌入膜中的P21D也会引起持久且稳定的扰动，这通过铕离子（EU3+）透过膜得以体现。对于嵌入膜中的P7D而言，这种类型的膜扰动非常轻微。得出的结论是，膜融合活性的差异基于肽与膜表面结合时膜的瞬时扰动以及肽嵌入膜中引起的稳定扰动。
