The electrogenerated chemiluminescence (ECL) that results from the oxidation of tris(1,10-phenanthroline)ruthenium(II), at a gold electrode in the presence of oxalate, was used to investigate the interaction of the Ru(II) chelate with calf thymus DNA. The decrease in ECL emission from the excited state, Ru(phen)3(2+*), in the presence of DNA, is ascribed to binding to binding of the chelate to ...

Development of potent new anti-Shigella agents for rapid and specific detection and treatment is of great importance. Aptamers, nucleic acid oligomers capable of specific binding to a wide range of non-nucleic acid targets, may be of value for this purpose. In the present study, we used a Systematic Evolution of Ligands by Exponential enrichment (SELEX) process to select DNA aptamers that b...

Here we report the synthesis of luminescent ruthenium complexes that bind DNA base pair mismatches. [Ru(bpy)2(tpqp)]Cl2 (tpqp = 7,8,13,14-tetrahydro-6-phenylquino[8,7-k][1,8]phenanthroline), [Ru(bpy)2(pqp)]Cl2 (pqp = 6-phenylquino[8,7-k][1,8]phenanthroline), and [Ru(bpy)2(tactp)]Cl2 [tactp = 4,5,9,18-tetraazachryseno[9,10-b]triphenylene] have been synthesized, and their spectroscopic properties...

development of potent new anti-shigella agents for rapid and specific detection and treatment is of great importance. aptamers, nucleic acid oligomers capable of specific binding to a wide range of non-nucleic acid targets, may be of value for this purpose. in the present study, we used a systematic evolution of ligands by exponential enrichment (selex) process to select dna aptamers that b...

Lactoferrin (Lf) is an iron-binding multi-functional glycoprotein which has numerous physiological functions such as iron transportation, anti-microbial activity and immune response. In this study, different in silico approaches were exploited to investigate Lf protein properties in a number of mammalian species. Results showed that the iron-binding site, DNA and RNA-binding sites, signal pepti...

Several multi-component DNA intercalating small molecules have been designed around ruthenium-based intercalating monomers to optimize DNA binding properties for therapeutic use. Here we probe the DNA binding ligand [μ-C4(cpdppz)2(phen)4Ru2](4+), which consists of two Ru(phen)2dppz(2+) moieties joined by a flexible linker. To quantify ligand binding, double-stranded DNA is stretched with optica...

We present evidence for a mechanism by which regulatory proteins may gain access to their target DNA sequences in chromatin. In this model, nucleosomes are dynamic structures, transiently exposing stretches of their DNA. Regulatory proteins gain access to DNA target sites in the exposed state, and bind with an apparent dissociation constant equal to their dissociation constant for naked DNA div...

We have cloned and expressed the ahdIC gene of the AhdI restriction-modification system and have purified the resulting controller (C) protein to homogeneity. The protein sequence shows a HTH motif typical of that found in many transcriptional regulators. C.AhdI is found to form a homodimer of 16.7 kDa; sedimentation equilibrium experiments show that the dimer dissociates into monomers at low c...

A thermodynamic study of copper ions by jack bean urease (JBU) was carried out at two temperatures of 27 and 37?C in Tris buffer (30 mM; pH=7.0) using an isothermal titration calorimetry. There is a set of twelve identical and non-interacting binding sites for copper ions. The intrinsic dissociation equilibrium constant and the molar enthalpy of binding are 285 µM and ?15.2 kJ/mol at 27?C and 3...