Synthetic biology is a rapidly growing field with applications in biotechnology and biomedicine. Through various approaches, remarkable achievements, such as cell and tissue engineering, have been already accomplished. In synthetic glycobiology, the engineering of glycan binding proteins is being exploited for producing tools with precise topology and specificity. We developed the concept of engineered chimeric lectins, i.e., Janus lectin, with increased valency, and additional specificity. The novel engineered lectin, assembled as a fusion protein between the β-propeller domain from Ralstonia solanacearum and the β-trefoil domain from fungus Marasmius oreades, is specific for fucose and α-galactose and its unique protein architecture allows to bind these ligands simultaneously. The protein activity was tested with glycosylated giant unilamellar vesicles, resulting in the formation of proto-tissue-like structures through cross-linking of such protocells. The engineered protein recognizes and binds H1299 human lung epithelial cancer cells by its two domains. The biophysical properties of this new construct were compared with the two already existing Janus lectins, RSL-CBM40 and RSL-CBM77_Rf. Denaturation profiles of the proteins indicate that the fold of each has a significant role in protein stability and should be considered during protein engineering.

合成生物学是一个快速发展的领域，在生物技术和生物医学中都有应用。通过各种方法，已经取得了显着的成就，例如细胞和组织工程。在合成糖生物学中，正在利用聚糖结合蛋白的工程来生产具有精确拓扑结构和特异性的工具。我们开发了工程嵌合凝集素的概念，即 Janus 凝集素，具有更高的效价和额外的特异性。新型工程凝集素，作为融合蛋白组装在青枯菌的 β-螺旋桨结构域和真菌Marasmius oreades的 β-三叶结构域之间, 对岩藻糖和 α-半乳糖具有特异性，其独特的蛋白质结构允许同时结合这些配体。用糖基化的巨型单层囊泡测试蛋白质活性，通过此类原始细胞的交联形成原始组织样结构。该工程蛋白通过其两个结构域识别并结合 H1299 人肺上皮癌细胞。将这种新构建体的生物物理特性与两种已有的 Janus 凝集素 RSL-CBM40 和 RSL-CBM77 _Rf进行了比较。蛋白质的变性特征表明，每种蛋白质的折叠对蛋白质稳定性都有重要作用，在蛋白质工程中应予以考虑。