Rigby-Singleton Shellie M, Davies Martyn C, Harris Helen, O'Shea Paul, Allen Stephanie
School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK.
Langmuir. 2006 Jul 4;22(14):6273-9. doi: 10.1021/la060114+.
The effect of the presequence peptide of cytochrome c oxidase subunit IV (p25) on supported phospholipid bilayers (SPBs) was visualized using atomic force microscopy (AFM). The presequence was found to cause the complete disruption of supported bilayers containing neutral lipids. At relatively low concentrations of presequence, the peptide was found to bind to the membrane, coalescing to form microdomains within the liquid-crystalline bilayer that were located predominantly at bilayer-mica boundaries. Further increases in peptide concentration resulted in the formation of holes within the SPB that were spanned by an interpenetrating network of narrower regions of the bilayer, which, at higher applied peptide concentrations, were observed to disappear through a budding process, ultimately leading to the formation of spherical structures at yet higher peptide concentrations. Within this paper, the impact the presequence has upon the structure and order of the membrane is discussed, as is the potential implication of this apparent solubilization process on the translocation of cytochrome c oxidase into the inner mitochondrial membrane.
利用原子力显微镜（AFM）观察了细胞色素c氧化酶亚基IV的前导肽（p25）对支撑磷脂双层（SPB）的影响。发现该前导肽会导致含有中性脂质的支撑双层完全破坏。在相对较低的前导肽浓度下，发现该肽会与膜结合，聚合并在液晶双层内形成微结构域，这些微结构域主要位于双层与云母的边界处。肽浓度的进一步增加导致SPB内形成孔洞，这些孔洞由双层较窄区域的相互贯穿网络跨越，在更高的肽应用浓度下，观察到这些孔洞通过出芽过程消失，最终在更高的肽浓度下导致球形结构的形成。在本文中，讨论了前导肽对膜结构和有序性的影响，以及这种明显的溶解过程对细胞色素c氧化酶转运到线粒体内膜的潜在影响。
