Resveratrol Effect on α-Lactalbumin Thermal Stability

Area of Science:

• Protein chemistry
• Biophysics
• Food science

Background:

• Alpha-lactalbumin (α-LA) is a major whey protein with significant nutritional value.
• Resveratrol (RESV) is a natural polyphenol with known antioxidant and potential health benefits.
• Understanding RESV's interaction with proteins like α-LA is crucial for food processing and potential therapeutic applications.

Purpose of the Study:

• To investigate the effect of resveratrol (RESV) on the thermal stability and structural changes of alpha-lactalbumin (α-LA).
• To elucidate the binding interactions between RESV and α-LA using molecular docking.
• To characterize RESV-induced aggregation of α-LA.

Main Methods:

• Differential Scanning Calorimetry (DSC) for thermal stability analysis.
• Circular Dichroism (CD) spectroscopy for conformational changes.
• Dynamic Light Scattering (DLS) for aggregate size distribution.
• Molecular docking simulations for binding site identification.

Main Results:

• RESV narrowed the thermal fingerprint of α-LA, shifting the first thermal transition (T1) to higher temperatures and the second (T2) to lower temperatures.
• CD data indicated RESV slightly demoted the formation of a β-sheet richer intermediate (BSRI) at T1 but promoted α-helix unfolding at T2.
• DLS measurements revealed RESV promoted the formation of larger protein aggregates upon prolonged incubation.

Conclusions:

• RESV modulates α-LA thermal unfolding pathways, stabilizing initial structural changes while promoting final unfolding.
• RESV binding influences α-LA's secondary structure and promotes aggregation, particularly of unbound RESV.
• These findings provide insights into RESV-protein interactions relevant to food systems and biomaterial development.