This paper reports a new approach to detect ribozyme cleavage product based on the molecular-beacon-ligation system. The molecular beacon, designed in such a way that one-half of its loop is complementary to ribozyme cleavage product, is used to monitor ligation process of RNA/DNA com-plex in a homogeneous solution and to convert directly cleavage product information into fluorescence signal. The method need not label ribozyme and ribozyme substrate, which is fast, simple and ultra-sensitive for detection of cleavage product. Detection limit of the assay is 0.05 nmol/L. The cleavage product of hammerhead ribozyme against hepatitis C virus RNA (HCV-RNA) was detected perfectly based on this assay. Owing to its ultrasensitivity, excellent specificity, convenience and fidelity, this method might hold out great promise in ribozyme reaction and ribozyme gene therapy.
MENG XiangXian TANG ZhiWen WANG KeMin TAN WeiHong YANG XiaoHai LI Jun GUO QiuPing
In recent years, specific detection of proteins is one of the hot issues about aptamers in proteomics. Here we reported a simple, sensitive and specific proximity-dependent protein assay with dual DNA aptamers. Thrombin was used as the model protein, and two aptamer probes with complementary se- quence at 3′-end were designed for the two distinct epitopes of the protein. Association of the two ap- tamers with thrombin resulted in stable hybrids due to the proximity of 3′-end, then polymerase reac- tion was induced. The amount of obtained dsDNA was indicated using the fluorescence dye Sybr Green I. The results showed that the initial velocity of polymerase reaction had a positive correlation with concentration of thrombin. The advantages of this dual-aptamer-based approach included simple and flexible design of aptamer probes, high selectivity and high sensitivity. The detection limit was 6.9 pmol/L.
YANG XiaoHai WANG Lei WANG KeMin TAN WeiHong TANG HongXing MENG XiangXian GUO QiuPing
1 Results 1,3-Dipolar cycloaddition reaction is one of the most common methods for preparing various five membered heterocycles,and provides a conveniet protocols for constructing C-C bond with functional groups.The reaction has also been successfully used in the syntheses of C-glycosides and other sacharride derivatives.We wish to present herein our recent approaches on the synthesis of novel C-amino-glycosides,C-aminodisaccharides,spiro heterocyclic glycosides and heterocycle linked C-disaccharides,et...
Li Xiao-liu, Zhang Ping-zhu, Wang Yan-po, Chen Hua(Department of Chemistry, Laboratory of Chemical Biology, Hebei University, Baoding, Hebei 071002, China)
