GLP4, a peptide from Ganoderma lingzhi directly targeting TBK1 to exert anti-inflammatory activity

This study investigated the anti-inflammatory activity, molecular target and interaction mechanism of Ganoderma lingzhi-derived peptide Gln-Arg-Val-Cys-Glu (GLP4). The results showed that in lipopolysaccharide (LPS)-induced inflammation in RAW264.7 cells, GLP4 significantly reduced the expression of COX-2, iNOS, TNF-α, IL-1β, and IL-6, and exhibited potent anti-inflammatory activities. GLP4 directly interacted with the target protein TBK1. Moreover, GLP4 mainly combined with the critical sites of TBK1 through hydrogen bonding and formed a stable complex. The binding affinity of GLP4 and TBK1 was 0.368 μmol/L. Further multispectral experiments showed that the interaction of GLP4 with TBK1 altered its secondary structure. Notably, GLP4 intervention directly inhibited the phosphorylation activity of TBK1 and affected the activation of NF-κB. Our study reported the inflammation-modulating ability of G. lingzhi mycelial peptides for the first time, providing valuable insights into the natural anti-inflammatory activity of functional foods or nutritional supplements.