Study of Phanerochaete chrysosporium Secretome Revealed Protein Glycosylation as a Substrate-Dependent Post-Translational Modification

Lignocellulosic
biomass is a potential sustainable resource of
mixed sugars that can be exploited for biofuel and other biomaterials. Phanerochaete chrysosporium (P. chrysosporium) produce an arsenal of extracellular enzymes, the secretome, for
efficiently degrading lignocellulosic biomass. Post-translational
modifications (PTMs) of these biomass-degrading enzymes generate remarkable
diversity, complexity, heterogeneity and also alter physiological
behavior, function, and activities. Identification of PTMs and the
sites of modifications of these secreted proteins remain as an essential
but unexploited step to understand the biomass degradation mechanism.
Therefore, this study applied electrostatic repulsion hydrophilic
interaction chromatography (ERLIC) for glycopeptides enrichment and
coupled with tandem mass spectrometry (LC-MS/MS) analysis for glycosylated
secreted enzymes of P. chrysosporium during glucose, cellulose, and lignin degradation. Varied groups
of enzymes, including cellulases, glycoside hydrolases, hemicellulases,
lignin-degrading enzymes, were glycosylated. The comparisons of the
glycosylated secreted enzymes of P. chrysosporium in glucose, cellulose, and lignin culture conditions revealed glycosylation
as substrate-dependent PTMs.