How Photoswitchable Lipids Affect the Order and Dynamics of Lipid Bilayers and Embedded Proteins
How Photoswitchable Lipids Affect the Order and Dynamics of Lipid Bilayers and Embedded Proteins
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DOI：
10.1021/jacs.1c03524
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发表时间：
2021-06-16
影响因子：
15
通讯作者：
Glaubitz, Clemens
中科院分区：
文献类型：
--
作者：
Doroudgar, Mahmoudreza;Morstein, Johannes;Glaubitz, Clemens
通过光改变磷脂膜的性质是对膜蛋白和细胞功能进行非侵入性操作的一种有吸引力的选择。在其酰基链内含有偶氮苯基团的脂质，如偶氮磷脂酰胆碱（AzoPC），是通过光诱导的反式 - 顺式异构化来操纵脂质有序性和动力学的合适工具。然而，这些光可切换脂质在原子水平上的作用仍知之甚少。在此，通过化学位移和偶极碳 - 氢序参数测量，利用固态核磁共振对含有偶氮磷脂酰胆碱、棕榈酰油酰磷脂酰乙醇胺（POPE）和棕榈酰油酰磷脂酰甘油（POPG）的脂质体进行了表征。在紫外光照射下，可实现有效的反式 - 顺式转换，导致脂质体主体酰基链内碳 - 氢序参数局部降低。在含有整合膜蛋白大肠杆菌二酰基甘油激酶的脂质体中，这种效应更加显著。通过在氮 - 碳 - 阿尔法（NCA）谱中交叉峰强度的改变所观察到的情况可知，该蛋白通过分子动力学的位点特异性增加来响应光诱导的反式 - 顺式异构化。这项研究为使用光可切换脂质通过光调节膜性质以诱导嵌入膜蛋白内的动态变化提供了概念验证演示。
Altering the properties of phospholipid membranes by light is an attractive option for the noninvasive manipulation of membrane proteins and cellular functions. Lipids with an azobenzene group within their acyl chains such as AzoPC are suitable tools for manipulating lipid order and dynamics through a light-induced trans-to-cis isomerization. However, the action of these photoswitchable lipids at the atomic level is still poorly understood. Here, liposomes containing AzoPC, POPE, and POPG have been characterized by solid-state NMR through chemical shift and dipolar CH order parameter measurements. Upon UV-light illumination, an efficient trans-to-cis conversion can be achieved resulting in a localized reduction of the CH order parameter within the bulk lipid acyl chains. This effect is even more pronounced in liposomes containing the integral membrane protein E. coli diacylglycerol kinase. The protein responds to the light-induced trans-to-cis isomerization by a site-specific increase in the molecular dynamics as observed by altered cross peak intensities in NCA spectra. This study represents a proof-of-concept demonstration for the use of photoswitchable lipids to modulate membrane properties by light for inducing dynamic changes within an embedded membrane protein.