Battista Edmondo, Scognamiglio Pasqualina L, Di Luise Nunzia, Raucci Umberto, Donati Greta, Rega Nadia, Netti Paolo A, Causa Filippo
Interdisciplinary Research Centre on Biomaterials (CRIB) Università degli studi di Napoli "Federico II", Piazzale Tecchio 80, 80125, Napoli, Italy.
J Mater Chem B. 2018 Feb 28;6(8):1207-1215. doi: 10.1039/c7tb03107f. Epub 2018 Feb 7.
Synthetic receptors for biomacromolecules lack the supramolecular self-assembly behavior typical of biological systems. Here we propose a new method for the preparation of protein imprinted polymers based on the specific interaction of a peptide multi-functional block with a protein target. This peptide block contains a protein-binding peptide domain, a polymerizable moiety at the C-terminus and an environment-sensitive fluorescent molecule at the N-terminus. The method relies on a preliminary step consisting of peptide/protein supramolecular assembly, followed by copolymerization with the most common acrylate monomers (acrylamide, acrylic acid and bis-acrylamide) to produce a protein imprinted hydrogel polymer. Such a peptide block can function as an active assistant recognition element to improve affinity, and guarantees its effective polymerization at the protein/cavity interface, allowing for proper placement of a dye. As a proof of concept, we chose Bovine Serum Albumin (BSA) as the protein target and built the peptide block around a BSA binding dodecapeptide, with an allyl group as the polymerizable moiety and a dansyl molecule as the responsive dye. Compared to conventional approaches these hydrogels showed higher affinity (more than 45%) and imprinted sensitivity (about twenty fold) to the target, with a great BSA selectivity with respect to ovalbumin (α = 1.25) and lysozyme (α = 6.02). Upon protein binding, computational and experimental observations showed a blue shift of the emission peak (down to 440 nm) and an increase of fluorescence emission (twofold) and average lifetime (Δτ = 4.3 ns). Such an approach generates recognition cavities with controlled chemical information and represents an a priori method for self-responsive materials. Provided a specific peptide and minimal optimization conditions are used, such a method could be easily implemented for any protein target.
生物大分子的合成受体缺乏生物系统典型的超分子自组装行为。在此，我们提出一种基于肽多功能嵌段与蛋白质靶标的特异性相互作用制备蛋白质印迹聚合物的新方法。该肽嵌段包含一个蛋白质结合肽结构域、一个位于C端的可聚合部分以及一个位于N端的环境敏感荧光分子。该方法依赖于一个初步步骤，即肽/蛋白质超分子组装，随后与最常见的丙烯酸酯单体（丙烯酰胺、丙烯酸和双丙烯酰胺）共聚，以制备蛋白质印迹水凝胶聚合物。这样的肽嵌段可以作为一个活性辅助识别元件来提高亲和力，并保证其在蛋白质/空腔界面处的有效聚合，从而使染料能够正确定位。作为概念验证，我们选择牛血清白蛋白（BSA）作为蛋白质靶标，并围绕一个BSA结合十二肽构建肽嵌段，以烯丙基作为可聚合部分，以丹磺酰分子作为响应染料。与传统方法相比，这些水凝胶对靶标显示出更高的亲和力（超过45%）和印迹灵敏度（约20倍），对卵清蛋白（α = 1.25）和溶菌酶（α = 6.02）具有很高的BSA选择性。在蛋白质结合后，计算和实验观察表明发射峰发生蓝移（低至440 nm），荧光发射增加（两倍），平均寿命增加（Δτ = 4.3 ns）。这种方法产生具有可控化学信息的识别空腔，代表了一种用于自响应材料的先验方法。只要使用特定的肽和最少的优化条件，这种方法就可以很容易地应用于任何蛋白质靶标。
