Dual effect of 2D WS₂ nanoparticles on the lysozyme conformation

Area of Science:

• Biophysics
• Materials Science
• Protein Chemistry

Background:

• Lysozyme is a model protein for studying protein folding and aggregation.
• Amyloid formation is implicated in various diseases.
• Two-dimensional (2D) nanomaterials offer unique properties for biological applications.

Purpose of the Study:

• To investigate the impact of 2D tungsten disulfide (WS₂) nanoparticles on the conformational changes of lysozyme protein.
• To determine how pH and protein concentration affect WS₂-induced structural modifications in lysozyme.
• To explore the influence of WS₂ on amyloid fibril formation and associated spectroscopic properties of lysozyme.

Main Methods:

• Fourier Transform Infrared (FTIR) spectroscopy to analyze secondary structure changes (α-helix, β-sheets, etc.) via Amide I band decomposition.
• Confocal microscopy with gold enhancement for visualizing amyloid fibrils.
• Fluorescent spectroscopy using Thioflavin T dye to confirm amyloid presence.

Main Results:

• 2D WS₂ nanoparticles induced conformational changes in lysozyme, varying with pH and protein concentration.
• WS₂ demonstrated a dual role in amyloid formation, capable of both inhibition and stimulation.
• Unusual spectral narrowing of Amide I and Amide II bands was observed for lysozyme incubated with WS₂ at acidic pH (2.5 and 3.5).

Conclusions:

• 2D WS₂ nanoparticles significantly interact with lysozyme, altering its secondary structure and aggregation propensity.
• The effect of WS₂ on lysozyme amyloidogenesis is complex and highly dependent on environmental conditions (pH, concentration).
• The observed spectroscopic anomalies suggest unique interactions between WS₂ and lysozyme under specific acidic conditions.