Humenik Martin, Preiß Tamara, Gödrich Sebastian, Papastavrou Georg, Scheibel Thomas
Department of Biomaterials, Faculty of Engineering Science, Universität Bayreuth, Prof.-Rüdiger-Bormann.Str. 1, 95447 Bayreuth, Germany.
Department of Physical Chemistry II, Faculty of Biology, Chemistry & Earth Sciences, Universität Bayreuth, Universitätsstraße 30, 95440 Bayreuth, Germany.
Mater Today Bio. 2020 Feb 24;6:100045. doi: 10.1016/j.mtbio.2020.100045. eCollection 2020 Mar.
Hydrogels are excellent scaffolds to accommodate sensitive enzymes in a protective environment. However, the lack of suitable immobilization techniques on substrates and the lack of selectivity to anchor a biocatalyst are major drawbacks preventing the use of hydrogels in bioanalytical devices. Here, nanofilm coatings on surfaces were made of a recombinant spider silk protein (rssp) to induce rssp self-assembly and thus the formation of fibril-based nanohydrogels. To functionalize spider silk nanohydrogels for bioselective binding of proteins, two different antithrombin aptamers were chemically conjugated with the rssp, thereby integrating the target-binding function into the nanohydrogel network. Human thrombin was selected as a sensitive model target, in which the structural integrity determines its activity. The chosen aptamers, which bind various exosites of thrombin, enabled selective and cooperative embedding of the protein into the nanohydrogels. The change of the aptamer secondary structure using complementary DNA sequences led to the release of active thrombin and confirmed the addressable functionalization of spider silk nanohydrogels.
水凝胶是在保护环境中容纳敏感酶的优良支架。然而，在底物上缺乏合适的固定技术以及缺乏锚定生物催化剂的选择性是阻碍水凝胶在生物分析装置中应用的主要缺点。在此，表面的纳米薄膜涂层由重组蜘蛛丝蛋白（rssp）制成，以诱导rssp自组装，从而形成基于原纤维的纳米水凝胶。为了使蜘蛛丝纳米水凝胶功能化以实现蛋白质的生物选择性结合，将两种不同的抗凝血酶适体与rssp进行化学偶联，从而将靶标结合功能整合到纳米水凝胶网络中。选择人凝血酶作为敏感的模型靶标，其结构完整性决定其活性。所选择的与凝血酶的各种外位点结合的适体能够使蛋白质选择性且协同地嵌入纳米水凝胶中。使用互补DNA序列改变适体二级结构导致活性凝血酶的释放，并证实了蜘蛛丝纳米水凝胶的可寻址功能化。
