Macroalgal Peptides with Predicted α-Glucosidase Inhibitory Activity: Preparation and Molecular Docking

Area of Science:

• Biochemistry
• Food Science
• Pharmacology

Background:

• Alpha-glucosidase inhibitors are crucial for managing type 2 diabetes.
• Marine algae, like Palmaria palmata, are a potential source of bioactive compounds.
• Enzymatic hydrolysis can yield peptides with enhanced biological activities.

Purpose of the Study:

• To investigate the alpha-glucosidase inhibitory potential of Palmaria palmata protein hydrolysates.
• To identify specific peptides responsible for the inhibitory activity.
• To explore the binding mechanisms of these peptides.

Main Methods:

• Enzymatic and alkaline treatments of Palmaria palmata proteins using various proteases.
• Dose-dependent alpha-glucosidase inhibition assays.
• Membrane fractionation and peptide identification (BIOPEP-UWM database).
• In silico molecular docking and physicochemical analysis.

Main Results:

• Alcalase®-derived treatments showed the highest alpha-glucosidase inhibition (IC50 = 2.48 mg·mL⁻¹).
• The <1 kDa fraction exhibited the strongest inhibition (IC50 = 1.94 mg·mL⁻¹).
• Three peptides (RADIPFRRA, DGIAEAWLG, FWSQIFGVAF) were identified as potential inhibitors.
• Docking studies revealed competitive and allosteric binding modes.

Conclusions:

• Low-molecular-weight peptides from Palmaria palmata, particularly Alcalase®-generated ones, possess significant alpha-glucosidase inhibitory activity.
• The identified peptides offer insights into the rational design of carbohydrate metabolism modulators.
• This study highlights Palmaria palmata as a valuable source for developing functional food ingredients or therapeutic agents.