Identification and characterization of chia seed peptides with ADH/ALDH activation activity: Insights from molecular...

Chia seed peptides that activate alcohol dehydrogenase (ADH)/ aldehyde dehydrogenase (ALDH) were identified through enzymatic protein hydrolysis, combined with ultrafiltration, peptidomics, and computational learning. The results showed that chia seed peptides in different molecular weight ranges exhibited distinctly different spectral and physicochemical properties. The 3-5 kDa fraction demonstrated stronger fluorescence properties, solution stability (ζ-potential value was -24.80 ± 0.22 mV), and thermal stability (30.2 % mass retention at 600 °C). The <3 kDa fraction exhibited significant ADH/ALDH activation activity (P < 0.05). The identification of peptide sequences and computational virtual screening of the <3 kDa fraction yielded 19 active peptides from 403 peptides. Subsequent molecular docking identified 4 optimal peptides: FYL, IPFVP, LFQP, and GIYP. Among these, the binding energies of FYL with ADH and ALDH were the highest (-13.81 kJ/mol, -27.99 kJ/mol). The interactions involve salt bridges (1), hydrogen bonds (3), and hydrophobic interactions (8-9 binding sites). The amino acid residues that actively interacted with FYL were as follows: for ADH, Lys101, Leu104, Gly196, Asp267, Ser197, Val287, Trp290, Thr262, Thr198, and Ser105; for ALDH, Arg264, Val265, Glu487, Leu262, Thr247, Asn261, Asp424, Leu269, Phe425, Ile159, Leu267, Asp239, and Glu487. Molecular dynamics simulations confirmed that FYL (Phe-Tyr-Leu) binding induces conformational changes in ADH/ALDH, increasing their flexibility and thereby, catalytic efficiency. This study provides a theoretical basis for developing chia seed peptides as functional ingredients, reveals their potential in alcohol metabolism regulation, and offers insights into peptide-enzyme interactions and functional food design.