Study of Phanerochaete chrysosporium secretome revealed protein glycosylation as a substrate-dependent post-translational modification.

Abstract

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.