Lipoic acid-palladium complex interaction with DNA, voltammetric and AFM characterization

Area of Science:

• Biochemistry
• Materials Science
• Electrochemistry

Background:

• Lipoic acid-palladium complex (LAPd) is a compound with potential biological applications.
• Understanding its interaction with biological molecules like DNA is crucial for its development.
• Dietary supplements containing LAPd, such as Poly-MVA, are commercially available.

Purpose of the Study:

• To investigate the interaction mechanism between LAPd and double-stranded DNA (dsDNA).
• To analyze the adsorption and redox properties of LAPd, its ligand lipoic acid (LA), and the Poly-MVA supplement.
• To determine if LAPd causes oxidative damage to dsDNA.

Main Methods:

• Atomic Force Microscopy (AFM) for visualizing molecular interactions and adsorption.
• Voltammetry using highly oriented pyrolytic graphite (HOPG) and glassy carbon electrodes.
• Electrochemical analysis of LA, LAPd, and Poly-MVA in solution and on electrode surfaces.

Main Results:

• LAPd molecules were observed to extend dsDNA, reducing knotting and bending.
• Voltammetry confirmed interactions between LAPd/Poly-MVA and dsDNA, with no detected oxidative damage.
• AFM revealed distinct adsorption patterns influenced by LAPd structure, concentration, and applied potential.
• Electrochemical potentials controlled LAPd dissociation, Pd(0) nanoparticle formation, or LA/palladium oxide layer generation.

Conclusions:

• LAPd interacts with dsDNA, altering its structure without causing oxidative damage.
• The adsorption and redox behavior of LAPd and related compounds are dependent on electrochemical conditions.
• These findings provide insights into the fundamental interactions of LAPd with DNA, relevant for its potential applications.