Intermolecular ion pairs (salt bridges) are crucial for protein-DNA association. For two protein-DNA complexes, we demonstrate that the ion pairs of protein side-chain NH3+ and DNA phosphate groups undergo dynamic transitions between distinct states in which the charged moieties are either in direct contact or separated by water. While the crystal structures of the complexes show only the solve...

The family of anticancer complexes that include the transition metal copper known as Casiopeínas® shows promising results. Two of these complexes are currently in clinical trials. The interaction of these compounds with DNA has been observed experimentally and several hypotheses regarding the mechanism of action have been developed, and these include the generation of reactive oxygen species, p...

It is well known that positrons can live long enough to form complexes with atoms. The theoretical study of these complexes is important to interpret experimental data from both positron scattering by atoms and molecules and positron annihilation spectroscopy. There are typically two different kinds of positron complexes. In one of them a positron attaches to a neutral or ionic atom or molecule...

DNA-binding motifs that are recognized by transcription factors (TFs) have been well studied; however, challenges remain in determining the in vivo architecture of TF-DNA complexes on a genome-scale. Here, we determined the in vivo architecture of Escherichia coli arginine repressor (ArgR)-DNA complexes using high-throughput sequencing of exonuclease-treated chromatin-immunoprecipitated DNA (Ch...

Direct and indirect oxidation of guanine in DNA produces guanidinohydantoin (Gh), which is capable of inhibiting replication and inducing mutations during cellular activities. Although some biochemical studies have proposed that Gh may induce exclusively G to C mutations in DNA, other studies have predicted the occurrence of both G to C and G to T mutations. However, the exact reasons for these...

PURPOSE To determine whether complement-derived SC5b-9, the soluble nonlytic-fluid phase of the membrane attack complex, can be generated in normal human corneas when they are injured with lipopolysaccharide (LPS), ribitol teichoic acid (RTA) immune complexes, acid, or alkali. METHODS The experimental cornea of each donor pair was injected with 50 microliters of sterile saline containing 0.5 ...

Copper(II)bis(thiosemicarbazonato) complexes such as [(64)Cu]Cu-ATSM continue to be investigated for positron emission tomography (PET) imaging of tumour hypoxia. However, the currently proposed mechanisms for the mode of action of these complexes are unable to account fully for their observed biological behaviour. In order to examine the roles of the copper metal and the ligand, we designed a ...

2-(2-Furyl)-3-hydroxychromone (HL) reacts with MII ions in the formation of quadratic [Cu(L)2] (3), octahedral [M(L)2(OH2)2] (M = Co (1), Ni (2), Zn (4), Mn (5)) and seesaw [M(L)2] Sn (6), Pb (7)) complexes. Recrystallization complexes 1-3 presence pyridine lead to [M(L)2(py)2] (1a-3a) adducts. All compounds were characterized by Fourier transform infrared spectroscopy (FTIR). Complexes 1-7 ana...

Stark and absorption spectra for the hole-transfer band of the bacteriochlorophyll special pair in the wild-type and L131LH, M160LH, and L131LH/M160LH mutants of the bacterial reaction center of Rhodobacter sphaeroides are presented, along with extensive analyses based on nonadiabatic spectral simulations. Dramatic changes in the Stark spectra are induced by the mutations, changes that are read...

the vo(iv) complexes of tridentate ono schiff base ligands derived from 2- aminobenzoicacid and salicylaldehyde derivatives were synthesized and characterized by ir, uv–vis and elemental analysis. electrochemical properties of the vanadyl complexes were investigated by cyclic voltammetry. a good linear correlation was observed between the oxidation potentials and the electron-withdrawing charac...