Electrocatalysis in Nucleic Acid Molten Salts

Leone, Anthony; Hull, Dominic O.; Wang, Wei; Thorp, H. Holden; Murray, Royce W.

doi:10.1021/jp048995l

Cited by 5 publications

(2 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our conclusion is that Ru(bpy) 2 dppz 2+ does not bind to DNA in the anionic reverse micelles and instead binds to the surfactant headgroups. Recent work showing that Os(bpy) 2 dppz 2+ does not intercalate into DNA in molten salts substantiates this conclusion.…”

Section: Resultsmentioning

confidence: 90%

DNA Oxidation in Anionic Reverse Micelles: Ruthenium-Mediated Damage at Guanine in Single- and Double-Stranded DNA

et al. 2006

View full text Add to dashboard Cite

One-electron guanine oxidation in DNA has been investigated in anionic reverse micelles (RMs). A photochemical method for generating Ru3+ from the ruthenium polypyridyl complex tris(2-2'-bipyridine)ruthenium(II) chloride ([Ru(bpy)3]Cl2) is combined with high-resolution polyacrylamide gel electrophoresis (PAGE) to quantify piperidine-labile guanine oxidation products. As characterized by emission spectroscopy of Ru(bpy)3(2+), the addition of DNA to RMs containing Ru(bpy)3(2+) does not perturb the environment of Ru(bpy)3(2+). The steady-state quenching efficiency of Ru(bpy)3(2+) with K3[Fe(CN)6] in buffer solution is approximately 2-fold higher than that observed in RMs. Consistent with the difference in quenching efficiency in the two media, a 1.5-fold higher yield of piperidine-labile damage products as monitored by PAGE is observed for duplex oligonucleotide in buffer vs RMs. In contrast, a 13-fold difference in the yield of PAGE-detected G oxidation products is observed when single-stranded DNA is the substrate. Circular dichroism spectra showed that single-stranded DNA undergoes a structural change in anionic RMs. This structural change is potentially due to cation-mediated adsorption of the DNA phosphates on the anionic headgroups of the RMs, leading to protection of the guanine from oxidatively generated damage.

show abstract

Section: Resultsmentioning

confidence: 90%

DNA Oxidation in Anionic Reverse Micelles: Ruthenium-Mediated Damage at Guanine in Single- and Double-Stranded DNA

et al. 2006

View full text Add to dashboard Cite

show abstract

“…Os(bpy) 2 (dppz)Cl 2 was a kind gift from Dr. Dominic Hull in Prof. H. Holden Thorp's group at the University of North Carolina. It was prepared according to the published procedures , and characterized by UV−visible spectrophotometry, cyclic voltammetry, and elemental analysis.…”

Section: Methodsmentioning

confidence: 99%

Chemical-Induced Unfolding of Cofactor-Free Protein Monitored by Electrochemistry

Guo

2006

Anal. Chem.

View full text Add to dashboard Cite

Protein folding has been studied extensively with an aim to better understanding of the relationship between protein sequence, structure, and function. A large variety of techniques have been developed and utilized to probe protein conformation and folding/unfolding transition. In this report, electrochemical monitoring of urea-induced unfolding of a large cofactor-free protein, bovine serum albumin (BSA), is described. Enhanced electrochemical oxidation of tyrosine and tryptophan in free amino acids and in BSA was achieved on an indium tin oxide electrode by using an electron mediator, Os(bpy) 2 dppz (bpy ) 2,2′-bipyridine, dppz ) dipyrido[3,2-a:2′,3′-c]phenazine). The oxidation current was used as a signal reporter in the monitoring of urea-induced BSA denaturation. At high urea concentrations, the electrochemical signal increased by 3-fold relative to the native protein. The increase is attributed to the closer contact between the oxidizable residues in the unfolded BSA and Os(bpy) 2 dppz. The degree of unfolding assessed by electrochemistry correlates well with the established fluorescence technique in the range of 0-10 M urea. The method can be used to investigate the unfolding process of other cofactor-free proteins.

show abstract