Ecofriendly gold nanoparticles - Lysozyme interaction: Thermodynamical perspectives.

Area of Science:

• Biophysics
• Nanotechnology
• Biochemistry

Background:

• Lysozyme (Lys) is a crucial enzyme in biological systems.
• Biosynthesized gold nanoparticles (GNP) offer unique properties for biomedical applications.
• Understanding protein-nanoparticle interactions is vital for developing new therapeutic and diagnostic tools.

Purpose of the Study:

• To elucidate the interaction mechanism between biosynthesized gold nanoparticles (GNP) and lysozyme (Lys).
• To characterize the binding affinity, thermodynamic parameters, and structural impact of GNP on Lys.
• To explore energy transfer dynamics between Lys and GNP.

Main Methods:

• Multi-spectroscopic approach (UV-Vis, fluorescence spectroscopy).
• Förster's non-radiative energy transfer (FRET) theory.
• Circular dichroism (CD) spectroscopy.
• Nuclear Magnetic Resonance (NMR) spectroscopy.

Main Results:

• A moderate association constant (K_app = 2.66×10⁴ L/mol) and a binding constant (K_b) indicating temperature-dependent binding.
• Thermodynamic analysis suggests a spontaneous interaction driven primarily by hydrophobic forces (ΔG = -27.86 kJ/mol at 298K).
• Förster's theory confirmed non-radiative energy transfer is possible between Lys and GNP (r=3.06nm, R_o=1.84nm).
• Circular dichroism and NMR spectra indicated no significant alteration in Lys secondary structure upon GNP interaction.

Conclusions:

• Biosynthesized gold nanoparticles interact spontaneously with lysozyme, primarily through hydrophobic forces.
• The interaction involves energy transfer and does not disrupt the secondary structure of lysozyme.
• This study provides valuable insights into the structural and thermodynamic aspects of protein-nanoparticle binding.