Glycosylation with mannose modulates the anti-inflammatory activity of low-molecular weight peptides from brewer's spent yeast mannoproteins

Abstract

Mannoproteins from brewer's spent yeast were extracted and subjected to simulated gastrointestinal digestion (SGID) with dialysis. The resulting dialysate (D), representing low-molecular weight peptides, was fractionated by affinity chromatography into DF1 (non-glycosylated peptides) and DF2 (mannose-linked peptides). SGID predominantly released low MW hydrophilic peptides (191–707 Da). D enhanced IL-10 production and gene expression in mouse spleen cells while suppressing IL-6 production and expression. This putative anti-inflammatory effect was more pronounced in DF1, emphasizing the role of non-glycosylated peptides in this context. Twenty-five peptides (478–1338 Da) were identified in DF1, nine of which exhibited high predicted anti-inflammatory potential; DIDKM showed the highest score. In contrast, DF2 contained O- and N-glycosylated peptides and elicited a pro-inflammatory response, which was predicted to be maximal for the N-glycosylated peptide INSTL. Thus, brewer's spent yeast low-molecular weight peptides exert diverse immunomodulatory actions on murine splenocytes, which are partly dependent on glycosylation.