Institute of Chemistry, Technical University of Berlin, Straße des 17. Juni 124, 10623 Berlin, Germany.
Anal Chem. 2020 Apr 7;92(7):4798-4806. doi: 10.1021/acs.analchem.9b03813. Epub 2020 Mar 13.
The research in biomedicine, cell signaling, diagnostics, and biocatalysis rely on selective protein binders that specifically capture a protein in a complex medium for either preparative or analytical use. These molecules are generally of biological origin and exposed to instability, denaturation, high cost, and inherently low binding capability. Imprinted polymers, serving as the artificial protein binders, demonstrate good potential to overcome these drawbacks. In this study, a novel epitope imprinting strategy is reported by employing double-cysteine-modified peptides as the templates and adsorbing the templates on a gold surface by means of forming self-assembled monolayer bridges, followed by electropolymerization to create a polymer network. The imprinted surface was initially designed to demonstrate specific affinity toward a short peptide (, the epitope) or a target protein (, neuron specific enolase) in buffer. This surface was subsequently used to measure the cancer biomarker in human serum that allows detecting 12 times lower concentration than threshold level of the biomarker. The molecular receptors exhibited a < 65 pM for their respective target protein and low cross-reactivity with four nonspecific molecules. As compared to current strategies for the epitope imprinting, for example, through traditional, vertically adsorbed, or histidine-modified peptides, such a molecularly tunable system based on a surface-imprinting process may provide more efficient sensing systems with desirable affinity, sensitivity, and specificity in diagnostics applications.
在生物医学、细胞信号、诊断和生物催化领域的研究中，依赖于选择性的蛋白质结合物，这些结合物可以特异性地从复杂介质中捕获蛋白质，用于制备或分析。这些分子通常具有生物来源，容易不稳定、变性、成本高，并且固有结合能力低。印迹聚合物作为人工蛋白质结合物，具有克服这些缺点的良好潜力。在这项研究中，报道了一种新型的表位印迹策略，该策略采用双半胱氨酸修饰的肽作为模板，并通过形成自组装单分子桥将模板吸附在金表面上，然后进行电聚合以创建聚合物网络。印迹表面最初设计用于在缓冲液中特异性结合短肽（，表位）或目标蛋白质（，神经元特异性烯醇化酶）。然后，该表面用于测量人血清中的癌症生物标志物，可检测到比生物标志物阈值低 12 倍的浓度。分子受体对各自的目标蛋白质的亲和力 < 65 pM，与四个非特异性分子的交叉反应性低。与目前的表位印迹策略相比，例如通过传统的、垂直吸附的或组氨酸修饰的肽，基于表面印迹过程的这种分子可调系统可能在诊断应用中提供具有理想亲和力、灵敏度和特异性的更高效的传感系统。
