A kinetic study of the interaction of DNA with gold nanoparticles: mechanistic aspects of the interaction

Abstract

A kinetic study of the interaction of gold nanoparticles capped with N-(2-mercaptopropionyl)glycine with double stranded DNA was carried out in water and in salt (NaCl) solutions. The kinetic curves are biexponential and reveal the presence of three kinetic steps. The dependence of the reciprocal fast and slow relaxation time, on the DNA concentration, is a curve and tends to a plateau at high DNA concentrations. The simplest mechanism consistent with the kinetic results involves a simple three-step series mechanism reaction scheme. The first step corresponds to a very fast step that is related to a diffusion controlled formation of an external precursor complex (DNA, AuNPs); the second step involves the formation of a (DNA/AuNPs)(I) complex, as a result of the binding affinity between hydrophilic groups of the tiopronin and the DNA grooves. Finally, the third step has been interpreted as a consequence of a conformational change of the (DNA/AuNPs)(I) complex formed in the second step, to a more compacted form (DNA/AuNPs)(II). The values of the rate constants of each step decrease as NaCl concentration increases. The results have been discussed in terms of solvation of the species and changes in the viscosity of the solution.

Chemical Basis of Interactions Between Engineered Nanoparticles and Biological Systems

“…52 Some nanoparticles may also enter the cell nucleus and interact with nucleic acids, such as DNA. 53 Furthermore, nanoparticles in the blood or cells also adsorb small molecules, such as amino acids, biotin and folic acid. The depletion of small metabolites may also contribute to the toxicity of nanoparticles.…”

“…Such changes can be detected with DLS and ζ-potential measurements. 53,190,191 The nanoparticle-DNA complexes have altered electron absorption spectroscopic patterns, which can also be measured using UV-Vis spectroscopy. 192-194 DNA binding may increase the near-IR fluorescence of some nanoparticles.…”

“…Because of the weak intrinsic fluorescence emission of DNA, ethidium bromide (EB) or the low toxicity dye SYBR ® Green is used to label DNA molecules. 53,202 The resonance light scattering method has been used to detect metal ions and biomolecules. 203,204 Resonance light scattering from nanoparticles and DNA molecules is weak, but the scattering intensity is enhanced dramatically when nanoparticles and DNA bind to each other, permitting the quantification of nanoparticle-DNA interactions.…”

“…53,191,197,202,208-213 B-A and B-Z transitions can be identified by the appearance of characteristic CD bands. 197,211 NMR provides more detailed structural information than CD.…”

Dihydrolipoic Acid Conjugated Carbon Dots Accelerate Human Insulin Fibrillation

“…With recent nanotechnological developments in nanomedicine and biomedical engineering, much attention is focused on understanding the interaction and toxicity of nanomaterials on cellular components, such as proteins, plasma membranes and DNA [6][7][8][9][10]. Quantum dots (QDs), a class of typical nanoparticles, have been extensively studied with proteins to explore their potential biomedical applications.…”