Purification, Identification and Molecular Docking of Immunomodulatory Peptides from the Heads of .

In order to realize the high-value utilization of () heads, immunomodulatory peptides were prepared from the enzymatic hydrolysate of heads, and the action mechanism of immunomodulatory peptides was determined by molecular docking. The results showed that six proteases were used to hydrolyze head proteins, with the animal protease hydrolysate exhibiting the highest macrophage relative proliferation rate (MRPR). The enzymatic products were then sequentially purified by ultrafiltration, Sephadex G-15 gel chromatography, identified by liquid chromatography-mass spectrometry (LC-MS/MS), and finally selected for six immunomodulatory peptides (PSPFPYFT, SAGFPEGF, GPQGPPGH, QGF, PGMR, and WQR). These peptides maintained good immune activity under heat treatment, pH treatment, and in vitro gastrointestinal digestion. Molecular docking analysis indicated that these peptides showed great binding to both toll-like receptor 2 and 4 (TLR2 and TLR4/MD-2), leading to immunomodulation. The discarded heads in this article are considered to be promising food-borne immunomodulators that contribute to enhancing the immune function of the body.