Membrane Cholesterol Modulates Oligomeric Status and Peptide-Membrane Interaction of Severe Acute Respiratory Syndrome Coronavirus Fusion Peptide
Membrane Cholesterol Modulates Oligomeric Status and Peptide-Membrane Interaction of Severe Acute Respiratory Syndrome Coronavirus Fusion Peptide
复制标题
DOI：
10.1021/acs.jpcb.9b08455
复制
发表时间：
2019-12-19
影响因子：
3.3
通讯作者：
Chakraborty, Hirak
中科院分区：
文献类型：
--
作者：
Meher, Geetanjali;Bhattacharjya, Surajit;Chakraborty, Hirak
严重急性呼吸综合征冠状病毒 (SARS-CoV) 的 S2 糖蛋白的 N 端融合肽（残基 770-788）在与受体结合后暴露，对于病毒进入宿主细胞至关重要。融合肽改变宿主膜的膜组织和动力学以促进膜融合。一般来说，融合肽对膜的作用对靶膜的脂质组成敏感。在目前的工作中，我们利用稳态和时间分辨荧光光谱与圆二色光谱来阐明融合肽的结合、寡聚状态和二级结构及其对深度依赖性膜组织和动力学的影响。我们使用深度依赖性荧光探针 1,6-二苯基-1,3,5-己三烯 (DPH) 及其三甲基铵衍生物 (TMA-DPH) 来评估肽沿双层法线结合的效果。我们利用 TMA-DPH 和 DPH 之间色氨酸的能量转移效率来确定膜结合融合肽中存在的单独色氨酸的相对位置。我们进一步评估了膜胆固醇对肽的结合和组织的影响，以及肽结合在不同胆固醇浓度下对膜的深度依赖性物理性质的影响。我们的结果清楚地表明，膜胆固醇改变了膜结合肽的寡聚状态以及肽结合对深度依赖性膜组织和动力学的影响。胆固醇的作用很重要，因为真核宿主细胞含有大量胆固醇，这对于病原病毒的进入可能很重要。
The N-terminal fusion peptide (residues 770-788) of an S2 glycoprotein of the severe acute respiratory syndrome coronavirus (SARS-CoV), exposed upon receptor binding, is crucial for virus entry into the host cell. The fusion peptide alters the membrane organization and dynamics of the host membrane to facilitate membrane fusion. Generally, the effect of the fusion peptide on the membrane is sensitive to the lipid composition of target membranes. In the present work, we have utilized steady-state and time-resolved fluorescence spectroscopy in tandem with circular dichroism spectroscopy to elucidate the binding, oligomeric status, and secondary structure of the fusion peptide and its impact on the depth-dependent membrane organization and dynamics. We have used depth-dependent fluorescence probes, 1,6-diphenyl-1,3,5-hexatriene (DPH) and its trimethylammonium derivative (TMA-DPH), to evaluate the effect of the peptide binding along the bilayer normal. We have exploited the energy transfer efficiency of tryptophan between TMA-DPH and DPH to determine the relative location of the solitary tryptophan present in the membrane-bound fusion peptide. We have further evaluated the effect of membrane cholesterol on the binding and organization of the peptide and the impact of peptide binding on the depth-dependent physical properties of the membrane at various cholesterol concentrations. Our results clearly demonstrate that the membrane cholesterol alters the oligomeric status of the membrane-bound peptide and the effect of peptide binding on the depth-dependent membrane organization and dynamics. The role of cholesterol is important, as the eukaryotic host cells contain a good amount of cholesterol that might be important for the entry of pathogenic viruses.