Unravelling the Interaction Mechanism Between Oryzanol and Human Serum Albumin: An Integrated Approach Using...

Area of Science:

• Biochemistry
• Molecular Biology
• Pharmacology

Background:

• Gamma-oryzanol (Ory) is a bioactive compound from rice bran oil, known for antioxidant and cholesterol-lowering effects.
• Understanding its interaction with human serum albumin (HSA) is crucial for its therapeutic applications.

Purpose of the Study:

• To investigate the molecular mechanisms of interaction between gamma-oryzanol (Ory) and human serum albumin (HSA).
• To elucidate the binding site and stability of the HSA-Ory complex.

Main Methods:

• Fluorescence quenching assays
• Thermodynamic analyses
• Molecular dynamics simulations
• Molecular docking
• MM-PBSA calculations
• Competitive site marker experiments
• Steered molecular dynamics simulations

Main Results:

• Ory quenches HSA fluorescence via a mixed mechanism, forming a stable complex.
• The HSA-Ory complex is stabilized by hydrogen bonding and van der Waals interactions.
• Ory specifically binds to site I of HSA, interacting with residues like Trp214 and Lys199.
• Steered molecular dynamics revealed the role of specific residues in Ory dissociation from HSA.

Conclusions:

• Gamma-oryzanol (Ory) forms a stable complex with human serum albumin (HSA) at site I.
• The binding is primarily mediated by hydrogen bonds and van der Waals forces.
• This study provides detailed molecular insights into the HSA-Ory interaction mechanism.