We report a simple fluorometric method for detection of single-nucleotide changes in RNA using graphene oxide (GO) and RNA-cleaving DNAzyme. The fluorescent DNA probe (F-DNA) was annealed to RNA fragments generated by RNA cleavage with DNAzyme specific to mutant RNA. The F-DNA-RNA duplex attenuated the quenching of F-DNA fluorescence by GO.

Type II topoisomerases (Top2s) alter DNA topology via the formation of an enzyme-DNA adduct termed cleavage complex, which harbors a transient double-strand break in one DNA to allow the passage of another. Agents targeting human Top2s are clinically active anticancer drugs whose trapping of Top2-mediated DNA breakage effectively induces genome fragmentation and cell death. To understand the st...

KpnI REase recognizes palindromic sequence, GGTACC, and forms complex in the absence of divalent metal ions, but requires the ions for DNA cleavage. Unlike most other REases, R.KpnI shows promiscuous DNA cleavage in the presence of Mg2+. Surprisingly, Ca2+ suppresses the Mg2+-mediated promiscuous activity and induces high fidelity cleavage. To further analyze these unique features of the enzyme...

DNA cleavage stimulated by different topolsomerase H inhibitors shows in vitro a characteristic sequence specificity. Since chromatin struc tare and genome organization are expected to Influence drug-enzyme interactions and repair of drug-Induced DNA lesions, we investigated topoisomerase II DNA cleavage sites stimulated by teniposide (VM-26), 4-demethoxy-3'-deamino-3'-hydroxy-4'-epi-doxorubici...

The DNA sequence specificity of the cancer chemotherapeutic agent, bleomycin, has been investigated in three clones of human alpha RI-DNA. The three 340-base pair alpha RI-DNA sequences were almost identical in their nucleotide sequence enabling the study of subtle effects of base substitutions on bleomycin cleavage. By utilizing densitometer scanning and statistical analysis of the degree of b...

We have determined the mode of cleavage of superhelical SV40 DNA (Form I) by restriction endonucleases EcoRI and HpaII at 37 degrees C. By analysis with agarose gel electrophoresis and direct examination with dark field electron microscopy, we found that a large amount of the single-nicked circular DNA (Form II) was produced before the linear SV40 DNA (Form III) appeared. Thus, both restriction...

The cleavage of a DNA phosphodiester bond by Escherichia coli DNA topoisomerase I and the simultaneous covalent linkage of the enzyme to the 5’-phosphoryl group of the DNA at the cleavage site have been reported previously (Depew, R. E., Liu, L. F., and Wang, J. C. (1978) J. Biol. Chem 253, 511-518; Liu, L. F., and Wang, J. C. (1979) J. Biol. Chem 254, 11082-11088). With either E. coli or Micmc...

A series of novel bis-1,3,4-oxadizaoles were synthesized by oxidative cyclisation of respective Schiff bases derived from dicarbohydrazide using ceric ammonium nitrate (CAN) as catalyst. The synthesized compounds were screened for in vitro antibacterial activity against Staphylococcus aureus (MTCC 87), Escherichia coli (MTCC 46) and antifungal activity against Candida albicans (NCIM 3471) by tw...

introduction : activated protein c (apc) inactivates factor v by cleavage of its heavy chain at arg306, arg506, arg679, and lys994. mutational changes, which abolish apc cleavage sites, may predispose thrombosis by altering the inactivation process of factor v.  factor v leiden (arg506glu) has been demonstrated as a strong risk factor for thrombosis. in the current study, we have studied whethe...