Development of glyco-cluster materials systems to detect and neutralize pathogenic microorganisms

流感病毒和致病性大肠杆菌是流行的，有时对婴儿和老年患者来说是关键的。这些病原体通过细胞表面的低聚糖入侵我们的身体。细胞表面的唾液酸寡糖和α(L-4)-半乳糖基低聚糖分别是流感病毒和大肠杆菌志贺毒素(STX-I和STX-II)的识别信号。本研究旨在开发具有多价唾液酸和α(L-4)-半乳糖阵列的聚合物生物材料来检测、捕获和中和流感病毒和Vero毒素。我们成功地将二唾液酸复合型寡糖一锅转糖基化到α-葡萄糖功能化的三联吡啶Ru络合物上。所得糖偶联物表现出极好的凝集素亲和力，可与呈现多唾液酸苷阵列的聚合物相媲美。我们发现半乳-海藻糖α(L-L)-连接作为球糖基α(L-4)-连接的潜在用途。尽管半乳海藻糖与STx-I和Stx-II，尤其是与后者的结合仍然弱于天然的GB_2和GB_3球苷，但半乳-海藻糖可以通过引入β-葡萄糖苷或相关的其他单元来显著地整合结合亲和力。

Influenza viruses and pathogenic E.coli species are epidemic and sometimes critical for infants and aged patients. These pathogens invade our bodies through cell surface oligosaccharides. Sialo oligoaccharides and α(l-4)-galactobiosyl oligosaccharides on cell surfaces are the recovnition signals respectively for influenza viruses and E.coli Shiga toxins (Stx-I and Stx-II). The present research is aimed at developing polymer-based biomaterials having multivalent sialo and α(l-4)-Gal arrays to detect, capture, and neutralize influenza-viruses and vero toxins.We have succeeded in one-pot transglycosylation of disialo complex-type oligosaccharides onto an α-glucose-functionalized tris-bipyridine ruthenium complex. The resulting glycoconjugates exhibited excellent lectin-affinities comparable to that of polymers presenting multiple sialoside arrays. Also, they have strong luminescence that is markedly depressed by addition of virus, probably due to disruption of their saccharide-shell structures.We have found the potential utility of the galacto-trehalose α(l-l)-linkage as a promising substitute for the globosyl α(l-4)-linkage. Though the binding of the galacto-trehalose to Stx-I and Stx-II, particularly to the latter, is still weaker than that of the natural Gb_2 and Gb_3 globosides, galacto-trehalose may integrate the binding affinity significantly by additionally introducing β-glucoside moiety or related other units.