Immunomodulatory peptides from sturgeon cartilage: Isolation, identification, molecular docking and effects on RAW264.7 cells

Sturgeons (<i>Acipenseridae</i>), ancient fish known for their caviar, produce underutilized by-products like protein-rich cartilage, which is a source of high-quality bioactive peptides. This study investigates immunomodulatory peptides from sturgeon cartilage hydrolysates mechanisms. The study found that sturgeon cartilage hydrolysate F2-7 and its key peptides(DHVPLPLP and HVPLPLP)significantly promoted RAW267.4 cell proliferation, NO release, and phagocytosis (<i>P</i> < 0.001).Additionally, western blotting confirmed that F2-7 enhances immune response by increasing the expression of P-IKKα/β, IΚΚ, p65, and P-p65 proteins in the NF-κB signalling pathway (<i>P</i> < 0.01). Molecular docking further demonstrated that DHVPLPLP and HVPLPLP bind to NF-κB pathway proteins via hydrogen bonding, with low estimated binding energies (-2.75 and -1.64; -6.04 and -4.75 kcal/mol), thus establishing their role as key immune peptides in F2-7. Therefore, DHVPLPLP and HVPLPLP have the potential to be developed as dietary supplements for immune enhancement. Their ability to enhance immune function provides a theoretical basis for novel immune supplements.