A novel fluorescence sensing system using a photochromism-based assay (P-CHROBA) technique for the detection of target proteins
作者:Kin-ya Tomizaki、Hisakazu Mihara
DOI:10.1039/b501877n
日期:——
In the post-genomic era a number of biological technologies, including protein-detecting microarrays which can detect molecular interactions based on changes in fluorescence intensity, have been developed to investigate complicated protein functions and networks. However, the ability of such techniques to obtain reproducible and quantitative results can be compromised due to the need for the immobilization of capture agents and the labelling analytes with chromophores. In the present study, first we report the design and synthesis of photochromic spiropyran-containing peptides and then demonstrate a unique fluorescence sensing system comprising a photochromism-based assay (P-CHROBA) technique to distinguish between target proteins. The spiropyran moiety in the peptides exhibited characteristic physicochemical properties in the SP-to-MC isomerization (thermocoloration) and the MC-to-SP photoisomerization (photobleaching) depending upon changes in micro-environments such as the dielectric constants of solvents and steric hindrances generated by molecular interactions. We attempted to detect protein–peptide interactions using reproducible MC-to-SP photoisomerization properties by monitoring the fluorescence decay of the MC form in the peptide. This can reduce background fluorescence signals caused by emission from excess reagents and avoid the laborious introduction of probing molecules to analytes and the immobilization of capture agents onto solid surfaces. The protein fingerprints (PFPs) based on the photoisomerization properties could successfully distinguish between six different model proteins, and the combination of the P-CHROBA and PFP technique would be a powerful tool for profiling target proteins with reproducible and reliable results.
在后基因组时代,已经开发了许多生物技术来研究复杂的蛋白质功能和网络,包括可以根据荧光强度的变化检测分子相互作用的蛋白质检测微阵列。然而,由于需要固定捕获剂和用发色团标记分析物,此类技术获得可重复和定量结果的能力可能会受到影响。在本研究中,我们首先报告了含螺吡喃光致变色肽的设计和合成,然后展示了一种独特的荧光传感系统,该系统包括基于光致变色的测定(P-CHROBA)技术来区分靶蛋白。肽中的螺吡喃部分在 SP 到 MC 异构化(热着色)和 MC 到 SP 光异构化(光漂白)中表现出特有的物理化学性质,具体取决于微环境的变化,例如溶剂的介电常数和产生的空间位阻通过分子相互作用。我们尝试通过监测肽中 MC 形式的荧光衰减,利用可重复的 MC 到 SP 光异构化特性来检测蛋白质-肽相互作用。这可以减少由过量试剂发射引起的背景荧光信号,并避免将探测分子费力地引入分析物以及将捕获剂固定到固体表面上。基于光异构化特性的蛋白质指纹(PFP)可以成功区分六种不同的模型蛋白质,P-CHROBA 和 PFP 技术的结合将成为分析目标蛋白质的有力工具,并获得可重复且可靠的结果。