Mechanisms of Influenza Virus HA2 Peptide Interaction with Liposomes Studied by Dual-Wavelength MP-SPR
Mechanisms of Influenza Virus HA2 Peptide Interaction with Liposomes Studied by Dual-Wavelength MP-SPR
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DOI：
10.1021/acsami.2c09039
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发表时间：
2022-07-14
影响因子：
9.5
通讯作者：
Chaix, Carole
中科院分区：
文献类型：
--
作者：
Belkilani, Meryem;Farre, Carole;Chaix, Carole
基于磷脂的脂质体层被用作有效的仿生膜模型，以研究流感病毒血凝素 HA2 亚基的 pH 依赖性融合肽 (E4-GGYC) 的结合。为此，采用多参数表面等离子共振方法 (MP-SPR) 通过实时记录传感图来监测两个 pH 值（4.5 和 8）下的肽-脂质体相互作用，无需标记。首先将生物素化脂质体作为单层固定在涂有链霉亲和素层的 SPR 金芯片表面上。在两种 pH 值下生成多组具有不同 HA2 肽浓度的传感图。应用双波长菲涅耳层建模来计算脂质体层的厚度（d）和折射率（n），以监测其与肽相互作用时光学参数的变化。在酸性pH下，螺旋形式的肽进入脂质体的脂质双层，诱导囊泡膨胀并增加膜的坚固性。相反，在 pH 8 时观察到脂质体收缩，这与肽未插入磷脂双层有关。通过使用 Trace Drawer 软件将“OneToOne”模型拟合到实验传感图，确定 pH 4.5 下肽/脂质体相互作用的平衡解离常数 K-D = 4.7 X 10(-7) M。我们的实验方法表明，浓度高达 100 μM 的 HA2 肽在 pH 4.5 时不会对脂质体产生破坏。
A phospholipid-based liposome layer was used as an effective biomimetic membrane model to study the binding of the pH-dependent fusogenic peptide (E4-GGYC) from the influenza virus hemagglutinin HA2 subunit. To this end, a multiparameter surface plasmon resonance approach (MP-SPR) was used for monitoring peptide-liposome interactions at two pH values (4.5 and 8) by means of recording sensorgrams in real time without the need for labeling. Biotinylated liposomes were first immobilized as a monolayer onto the surface of an SPR gold chip coated with a streptavidin layer. Multiple sets of sensorgrams with different HA2 peptide concentrations were generated at both pHs. Dual-wavelength Fresnel layer modeling was applied to calculate the thickness (d) and the refractive index (n) of the liposome layer to monitor the change in its optical parameters upon interaction with the peptide. At acidic pH, the peptide, in its a helix form, entered the lipid bilayer of liposomes, inducing vesicle swelling and increasing membrane robustness. Conversely, a contraction of liposomes was observed at pH 8, associated with noninsertion of the peptide in the double layer of phospholipids. The equilibrium dissociation constant K-D = 4.7 X 10(-7) M of the peptide/liposome interaction at pH 4.5 was determined by fitting the "OneToOne" model to the experimental sensorgrams using Trace Drawer software. Our experimental approach showed that the HA2 peptide at a concentration up to 100 mu M produced no disruption of liposomes at pH 4.5.