Biomacromolecular charge chirality detected using chiral plasmonic nanostructures
Biomacromolecular charge chirality detected using chiral plasmonic nanostructures
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DOI：
10.1039/c9nh00525k
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发表时间：
2020-02-01
影响因子：
9.7
通讯作者：
Kadodwala, Malcolm
中科院分区：
文献类型：
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作者：
Rodier, Marion;Keijzer, Chantal;Kadodwala, Malcolm
HAS蛋白质等复杂生物分子的溶剂暴露表面的电荷分布是独特的指纹。这些电荷分布的手性导致了立体特异的静电相互作用，这有助于定义蛋白质相互作用的方式，有助于蛋白质-蛋白质相互作用的特异性。因此，它是理解生物学中化学过程的一个关键概念。目前还没有已知的光谱现象可以快速表征手性表面电荷分布。我们的研究表明，通过监测蛋白质-血浆纳米结构复合体的手性反应中的不对称性，可以检测到这一目前对于光学光谱学来说是“不可见”的基本属性。这一现象的独特能力被用来区分结构上同源的一系列蛋白质，来自不同生物体的II型脱氢奎宁酶(DHQase)。用传统的结构敏感光谱(即圆二色谱)无法区分这些蛋白质。我们发现，蛋白质之间的区别可以通过检测手性表面电荷分布的差异来实现。用一个简单的模型解释了这一现象，在这个模型中，等离子体结构的手性性质被金属中蛋白质的对映象电荷分布的诱导所扰动。这一新现象具有广泛的影响，它是区分结构上同源生物材料的有力工具，但也将提供与大分子相互作用相关的信息。
The charge distributions of solvent exposed surfaces of complex biomolecules such has proteins are unique fingerprints. The chirality of these charge distributions result in stereo-specific electrostatic interactions which help define how proteins interact with each other, contributing to specificity in protein-protein interactions. Thus it is a key concept in understanding chemical processes in biology. There is currently no known spectroscopic phenomenon that allows rapid characterisation of chiral surface charge distributions. We show that this essential property that is currently "invisible" to optical spectroscopy, can be detected by monitoring asymmetries in the chiroptical response of protein-plasmonic nanostructure complexes. The unique capabilities of the phenomenon are utilised to discriminate between a structurally homologous series of proteins, type II dehydroquinase (DHQase) derived from different organisms. The proteins are indistinguishable with conventional structurally sensitive spectroscopy (i.e. circular dichroism). We show that discrimination between proteins can be achieved by detecting differences in chiral surface charge distributions. The phenomenon is explained with a simple model whereby the chiroptical properties of the plasmonic structures are perturbed by the induction of an enantiomeric mirror image charge distribution of the protein in the metal. This new phenomenon has broad impact, it is a powerful tool for discriminating between structurally homologous biomaterials, but will also provide information relevant to macromolecular interactions.