Nanomolar protein sensing with embedded receptor molecules
Nanomolar protein sensing with embedded receptor molecules
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DOI：
10.1021/ja045785d
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发表时间：
2005-01-26
影响因子：
15
通讯作者：
Schrader, T
中科院分区：
文献类型：
--
作者：
Zadmard, R;Schrader, T
介绍了一种基于两亲性受体分子嵌入脂质单分子层的空气-水界面蛋白质传感的新概念。该方法开始于将少量（0.13当量）的一种或两种不同的杯[4]芳烃（在其上边缘装饰有带电官能团）掺入硬脂酸单层中。这些掺杂的单分子膜随后被证明吸引肽和蛋白质从水的亚相。根据主体结构，可以使单层对碱性或酸性蛋白质具有选择性。提出了一个工作模型，它解释了大的观察到的p/A的变化与重新纳入过量的受体分子到脂质单层后，与带相反电荷的蛋白质形成复合物。这需要在蛋白质表面上自组装多个杯芳烃单元，其以合作方式结合蛋白质。不透明带电的杯芳烃衍生物在单层内不形成分子胶囊，而是在脂质层内保持分离，采用垂直取向。它们联合收割机了氢键供体和受体的能力，从而显着提高了传感器系统对蛋白质的灵敏度，将检测限推高至10 pM浓度。从单层内的各种受体单元获得的对相同蛋白质的响应模式产生了该蛋白质的指纹，因此可以在纳摩尔浓度下选择性地检测（模式识别）。
A new concept of protein sensing at the air-water interface is introduced, based on amphiphilic receptor molecules embedded in a lipid monolayer. The process begins with incorporation of a small amount (0.13 equiv) of one or two different calix[4]arenes, adorned with charged functional groups at their upper rims, into a stearic acid monolayer. These doped monolayers are subsequently shown to attract peptides and proteins from the aqueous subphase. Depending on the host structure, the monolayers can be made selective for basic or acidic proteins. A working model is proposed, which explains the large observed p/A shifts with reincorporation of excess receptor molecules into the lipid monolayer after complex formation with the oppositely charged protein. This requires a self-assembly of multiple calixarene units over the protein surface, which bind the protein in a cooperative fashion. Oppositely charged calixarene derivatives do not form molecular capsules inside the monolayer, but rather remain separate inside the lipid layer, adopting a perpendicular orientation. They combine their hydrogen bond donor and acceptor capacities, and thus markedly enhance the sensitivity of the sensor system toward proteins, pushing the detection limits to 10 pM concentrations. The response pattern obtained from various receptor units inside the monolayer toward the same protein creates a fingerprint for this protein, which can hence be selectively detected at nanomolar concentrations (pattern recognition).