DEVELOPMENT OF THERAPUETIC AGENTS AGAINST VERO TOXIN PRODUCED BY E. COLI

研究了肠杆菌O-157产生的Vero毒素(VT)的特异性抑制物及检测探针的合成与表征。在详细分析Vero毒素N-糖苷酶活性反应机理的基础上，进行了分子设计。类似分子的28S rRNA是Vero毒素A链的底物，Gb3神经酰胺是Vero毒素B链细胞表面的糖受体。通过常规实验对一些具有Gaga四环结构的类似RNA分子的抑制作用进行了评价，结果表明，2‘-OMe类似物和硫代硫代类似物具有良好的药物应用前景，因为这些结构在生理条件下在细胞内甚至在体内都是稳定的。制备了含有生物素部分的GB3类似物，并将其固定在SPR传感器尖端。Gb3类似物与具有与Vero毒素相同的糖结合特异性的abrin C结合亲和力的观察表明，合成的类似物是检测Vero毒素的良好探针。荧光素标记的Gb3类似物和其他一些糖衍生物也是利用荧光光谱仪检测室性心动过速的良好探针。

Synthesis and characterization of specific inhibitor and detection probe of vero toxin (VT) produced by enterobacterium O-157 were studied. Molecular design based on detail analysis of reaction mechanisms of N-glycosidase activity of vero toxin was performed. Analogous molecules of 28S rRNA which is a substrate for vero toxin A chain and globotriose (Gb3) ceramide which is a glycoreceptor on cell surface for vero toxin B chain. Inhibitory effects of some analogous RNA molecules which have GAGA tetraloop structure in common were evaluated by conventional experiments and showed that 2'-OMe anaolgs and phosphorothioate analogs were promising structure for drug application because those structures are known to be stable in physiological conditions in cells and even in vivo. Gb3 analogs bearing biotin moiety were prepared and immobilized on SPR sensor tip. Obsevations of binding affnities of the Gb3 analogs and abrin C which has the same specificity of sugar binding as vero toxin suggested that synthesized analogs were good detection probes for vero toxin. Fluorecein labeled Gb3 analogs and some other sugar derivatives were revealed that they are also good probes for the detection of VT using a fluorospectrometer.