梳状糖基化聚合物刷的化学-酶法构建及其蛋白质识别作用研究

Cell-surface carbohydrates (glycocalyx) play essential roles in living creatures. They generally act as molecular recognition sites in normal physiology and disease processes, including fertilization, development, differentiation, virus invasion, cancer cell metastasis and bacterial infection. “Carbohydrate–protein” interactions are the fundamental scientific issue in many cellular processes involving normal physiology as well as disease. Consequently, much attention has been paid on fabricating glycocalyx-like surfaces for further probing the “carbohydrate–protein” interactions and understanding the biology functions of glycocalyx in naturae. Artificial glycocalyx are considered as the most effective tool to investigate the carbohydrate-protein interaction and might be exploited for various applications in glycotechnology, e.g., for diagnosis of diseases, for bio-separation, and for constructing scaffold materials for tissue engineering. Among such artificial glycocalyx, comblike glycopolymers have obtained special attentions and are emerging as an important tool to mimic multivalent ligands in nature and to perform similar functions in recognition. We present a detailed picture to fabricate a comblike glycopolymer brushes as artificial glycocalyx. The linear maltose-anchored polymer brushes were first constructed as substrate acceptor by surface-initiated atom transfer radical polymerization (SI-ATRP). Enzyme catalyzed polymerization was then used to grow polysaccharide side chains consisting of α-D-glucose residues from the end maltose moiety of the grafted polymer main chains using sucrose as donor substrate. The above combined reactions ultimately resulted in a comblike glycopolymer brush. The purpose of this study is to pursue a promising method for fabricating artificial glycocalyx with comblike structure, and enhance the possibility of using such artificial glycocalyx for potential applications in glycotechnology.

糖被在生命过程中起着十分重要的作用。一方面，其大量极性羟基可以为细胞提供保护屏障；更重要的是，“糖被”作为连接细胞和外界信息传递的媒介，参与了众多的生命分子识别过程，如抗体-抗原特异性结合、癌细胞侵袭扩散、细菌感染等。“糖-蛋白质”相互作用是聚糖实现其特殊生物学功能的基础。构建仿生“糖被”研究“糖-蛋白质”相互作用机理对于理解以及应用聚糖的特殊生物学功能具有重要的意义。梳状等复杂结构糖基化聚合物刷在结构上与生物细胞膜表面“糖被”更接近，更有利于深层次研究揭示“糖-蛋白质”相互作用机制。针对现有梳状糖基化聚合物刷构建方法的不足，本文设计一种结合表面引发原子转移自由基聚合（SI-ATRP）和酶法优点构建梳状糖基化聚合物刷的新方法。通过本课题的实施，可望为梳状糖基化聚合物刷的构建提供新思路，为深入揭示聚糖的生理活性提供有益启示，在糖基化仿生功能材料的制备及应用领域具有重要的科学价值。

糖被在生命过程中起着十分重要的作用。一方面，其大量极性羟基可以为细胞提供保护屏障；更重要的是，“糖被”作为连接细胞和外界信息传递的媒介，参与了众多的生命分子识别过程，如抗体-抗原特异性结合、癌细胞侵袭扩散、细菌感染等。“糖-蛋白质”相互作用是聚糖实现其特殊生物学功能的基础。构建仿生“糖被”研究“糖-蛋白质”相互作用机理对于理解以及应用聚糖的特殊生物学功能具有重要的意义。梳状等复杂结构糖基化聚合物刷在结构上与生物细胞膜表面“糖被”更接近，更有利于深层次研究揭示“糖-蛋白质”相互作用机制。针对现有梳状糖基化聚合物刷构建方法的不足，本项目研究结合表面化学催化和酶催化转糖基化法二者的优点，设计新型表面化学-酶法构建不同糖基类型的梳状糖基化聚合物刷；进一步基于此理论方法制备一系列表面不同糖基修饰的糖基化功能材料，如糖基化高分子微孔膜、糖基化中空纤维膜等，继而开展此类糖基化功能材料在蛋白质亲和吸附分离、细菌特异性捕捉黏附、细菌检测、抗菌、生物膜法细胞固定化发酵等领域的应用基础研究。本项目不仅为梳状糖基化聚合物刷的构建提供了新思路，在梳状糖基化聚合物刷微结构的有效构建、调控方面具有重要的科学价值；而且通过系统研究具有丰富微结构的糖基化聚合物刷与凝集素蛋白的特异性识别作用，也为阐明聚糖的特殊生物学功能提供了有益启示。此外，本研究也为开发新型糖基化功能材料，并开拓其在生物亲和分离、生物医学工程、生物传感、生物催化等众多领域的应用提供了理论指导。