ABSTRACT
Synthesis of a fluorescein-tagged circular structure of i-motif was accomplished during our investigations. The backbone circularity of this molecular probe and the presence of the fluorescent moiety within its structure were also confirmed through exonuclease hydrolysis and fluorescence spectroscopy.
Subject(s)
Fluorescein/chemistry , Molecular Probes/chemistry , Molecular Probes/chemical synthesis , Oligonucleotides/chemical synthesis , Base Pairing , Base Sequence , Electrophoretic Mobility Shift Assay , Hydrogen-Ion Concentration , Hydrolysis , Microinjections , Molecular Probes/genetics , Neoplasms/metabolism , Neoplasms/pathology , Oligonucleotides/chemistry , Oligonucleotides/genetics , Oligonucleotides/metabolism , Proteins/metabolism , Spectrometry, FluorescenceABSTRACT
A series of oligonucleotides with various lengths that contain nick and topoisomerase I-binding sites were designed. The interactions between these oligonucleotides and human topoisomerase I were investigated and the most efficient one among them has displayed IC(50) value of 6.3 nM. Our studies have also demonstrated that the position of the nick as well as the length of the oligonucleotides were crucial factors for the inhibition of this nuclear enzyme.
Subject(s)
Enzyme Inhibitors/pharmacology , Oligonucleotides/chemistry , Topoisomerase I Inhibitors , Base Sequence , Binding Sites , Catalysis , Cell Nucleus/enzymology , DNA/chemistry , Drug Design , Enzyme Inhibitors/chemistry , Humans , Inhibitory Concentration 50 , Models, Genetic , Molecular Sequence Data , Nucleic Acid Conformation , Substrate SpecificityABSTRACT
A study on the simultaneous separation of 13 pharmaceutical products by capillary electrophoresis with capacitively coupled contactless conductivity detection was presented. The parameters of the background electrolyte, such as pH, organic additives as well as types and concentrations of cyclodextrins (CD) were studied. The optimal separation conditions were achieved with a background electrolyte consisting of 9 mM Tris/5 mM lactic acid at pH 8.0, containing 5% n-propanol, 0.025% gamma-CD, 0.075% hydroxyl-beta-CD and 0.15% dimethyl-beta-CD. Limits of detections ranged from 61 to 1676 microg/L (S/N=3) and the relative standard deviations for migration time and peak area were below 2 and 6%, respectively. This demonstrated the potential of the capillary electrophoresis-capacitively coupled contactless conductivity detection method for biomedical and environmental analysis, as shown in the determination of pharmaceuticals identified as emerging pollutants in water samples.
