Scanning electrochemical microscopy was used to examine electron transfer across a self-assembled monolayer of thiol-modified DNA duplexes on a gold electrode. The apparent rate constant for heterogeneous ET from a solution redox probe, Fe(CN)6(3-/4-), to the gold surface through ds-DNA was 4.6 (+/-0.2) x 10(-7) cm/s. With the addition of Zn2+, which resulted in the formation of a metalated DNA...

the characteristics of manganese and iron binding to human apotransferrin (apo-tf) have been investigated and compared in this study. both metal ions were taken up by human apo-tf and formed complexes, with the maximum absorbances observed at 410 and 340 nm for manganese-transferrin (mn-tf) and 465 nm for iron-transferrin (fe-tf). addition of manganese (1.5 µg/ml) to the reaction mixture contai...

Surface plasmon resonance biosensor technique was used to study the binding of Moloney murine leukemia virus reverse transcriptase without RNase H domain (MMLV RT-) with DNA in the absence and in the presence of inhibitors. Different DNA substrates, including single-stranded DNA (ssDNA), DNA template-primer (T-P) duplex and gapped DNA, were immobilized on the biosensor chip surface using strept...

A nitrocellulose filter-binding assay has been developed to study the interaction of Xenopus transcription factor IIIA (TFIIIA) with its specific binding site on the 5 S RNA gene. The protein binds to a DNA restriction fragment containing a Xenopus oocyte 5 S RNA gene (5 S DNA) with an apparent association constant of 1.90 x 10(9) M-1 in 0.1 M salt, pH 7.5, at 22 degrees C. Under these assay co...

The DNA binding property of 5,10,15-Tris(4-carboxyphenyl) corrole (TCPC) was studied by UV-Visible, fluorescence and circular dichroism (CD) spectroscopic methods. TCPC can bind to ct-DNA via an outside binding mode with the binding constant of Kb = 1.05 × 10⁵ M(-1). TCPC also displayed good photonuclease activity, which involves singlet oxygen species (¹O₂). The binding constant between TCPC a...

p53 is a tumor suppressor protein that plays a significant role in apoptosis and senescence, preserving genomic stability, and preventing oncogene expression. Metal ions, such as magnesium and zinc ions, have important influences on p53-DNA interactions for stabilizing the structure of the protein and enhancing its affinity to DNA. In the present study, we systematically investigated the intera...

Sequence-specific DNA-binding proteins play a key role in many fundamental biological processes, such as transcription, DNA replication and recombination. Very often, these DNA-binding proteins introduce structural changes to the target DNA-binding sites including DNA bending, twisting or untwisting and wrapping, which in many cases induce a linking number change (Delta Lk) to the DNA-binding s...

a binding study of nickel ions by a new recombinant human growth hormone (hgh), produced as an injected drug, has been done at 27˚c in nacl solution (50 mm) using an isothermal titration calorimetry. there is a set of three identical and non-interacting binding sites for nickel ions. the intrinsic dissociation equilibrium constant and the molar enthalpy of binding are 40 μm and -16.5 kj/mol, re...

The effect of acetylation on the DNA binding properties of the rigidly conserved histone H4 amino-terminal tail has been studied in detail using the technique of thermal denaturation. The quantitative DNA-binding parameters for both the non- and fully acetylated H4 amino terminus have been determined from thermal denaturation data for complexes of the peptides bound to mixed sequence 146-base p...

The value of binding enthalpy change (ΔH) due to DNA–ligand complexformation has been determined by Van’t–Hoff mode having dependence of binding constant (K) on the reverse value of absolute temperature. Calculations that were carried out for DNA–ethidium bromide and DNA–mitoxantrone complexes showed, that if ΔH is determined from the values of K at two different temperatures, the calculated va...