Antimicrobial peptides temporins B and L induce formation of tubular lipid protrusions from supported phospholipid bilayers
Antimicrobial peptides temporins B and L induce formation of tubular lipid protrusions from supported phospholipid bilayers
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DOI：
10.1529/biophysj.106.091702
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发表时间：
2006-12-01
影响因子：
3.4
通讯作者：
Kinnunen, Paavo K. J.
中科院分区：
文献类型：
--
作者：
Domanov, Yegor A.;Kinnunen, Paavo K. J.
抗微生物肽时间蛋白B和L与由磷脂酰胆碱和磷脂酰甘油（4：1，mol/mol）组成的支持的脂质双层（SL B）模型膜的结合引起纤维状突起的形成，通过荧光脂质类似物和标记的肽的荧光显微镜可见。在低肽-脂质比（P/L <类似于1：5）下的多色成像揭示了膜结合肽的初始面内分离和脂质从肽富集区域的部分排除。随后，在较高的P/L，许多灵活的脂质纤维被视为从富含脂质的区域生长。原纤维的直径< 250 nm，长度可达1 mm。原纤维的形成降低了平面内的异质性，并导致结合肽在平面双层和原纤维上相对均匀的再分布。脂纤维的物理性质表明它们具有管状结构。我们的数据表明，单独的肽-脂质相互作用可以提供一个驱动力的自发膜形状的转变，导致小管生长和伸长。进一步的实验揭示了正曲率应变在蛋白质合成过程中的重要性以及肽上足够的正电荷（>= +2）。所观察到的膜转化可以提供一个简化的细胞内管状结构和细胞间连接的形态发生的体外模型。
The binding of the antimicrobial peptides temporins B and L to supported lipid bilayer (SLB) model membranes composed of phosphatidylcholine and phosphatidylglycerol (4:1, mol/mol) caused the formation of fibrillar protrusions, visible by fluorescent microscopy of both a fluorescent lipid analog and a labeled peptide. Multicolor imaging at low peptide-to-lipid ratios (P/L < similar to 1:5) revealed an initial in-plane segregation of membrane-bound peptide and partial exclusion of lipid from the peptide-enriched areas. Subsequently, at higher P/L numerous flexible lipid fibrils were seen growing from the areas enriched in lipid. The fibrils have diameters < 250 nm and lengths of up to similar to 1 mm. Fibril formation reduces the in-plane heterogeneity and results in a relatively even redistribution of bound peptide over the planar bilayer and the fibrils. Physical properties of the lipid fibrils suggest that they have a tubular structure. Our data demonstrate that the peptide-lipid interactions alone can provide a driving force for the spontaneous membrane shape transformations leading to tubule outgrowth and elongation. Further experiments revealed the importance of positive curvature strain in the tubulation process as well as the sufficient positive charge on the peptide (>= +2). The observed membrane transformations could provide a simplified in vitro model for morphogenesis of intracellular tubular structures and intercellular connections.