Anticancer Effects of Pleurotus salmoneostramineus Protein Hydrolysate on HepG2 Cells and In Silico Characterization of Structural Effects of Chromoprotein-Derived Peptides on the Mitochondrial Uncoupling Protein 2 (UCP2)

Background: Pleurotus salmoneostramineus is acknowledged as a reliable source of high-quality protein, with its protein concentrates, hydrolysates, and peptides potentially offering health benefits to humans. However, studies validating the medicinal effects of P. salmoneostramineus proteins, particularly the pink chromoprotein, are currently absent. Methods: This study explores anticancer peptides from the chromoprotein of P. salmoneostramineus, evaluating their ability to bind UCP2 via in silico analysis. Additionally, it assesses the protein hydrolysate from P. salmoneostramineus (PSPs) effect on HepG2 cell proliferation and mitochondrial metabolism, focusing on uncoupling protein activity. Results: Eight peptides were identified as potential UCP2 inhibitors. According to mACPpred2.0 and CSM-peptides servers, the peptides TSMQSSL, QEGQKL, SEDSGEA, and GRNSL exhibit promising anticancer properties. These anticancer peptides yielded the following docking scores (kcal/mol) when tested against UCP2: TSMQSSL (−166.75), QEGQKL (−126.06), SEDSGEA (−99.93), and GRNSL (−137.93). Molecular dynamics simulations have shown that the peptides establish stable interactions with UCP2 through salt bridges, hydrophobic interactions, and hydrogen bonds, implying that hydrogen bonding with RRR88 and FVW92 causes conformational changes in UCP2. Moreover, the outcomes of this study indicated that PSPs possess an antiproliferative effect on HepG2 cells and lower mitochondrial bioenergetics, especially UCP2 activity. Conclusions: These findings suggest that peptides from P.salmoneostramineus can inhibit UCP2, offering a promising approach for cancer prevention, playing therapeutic roles in treatment, and providing a basis for designing peptide-based cancer therapies.