Revisiting chicken egg white: a glycoproteomic approach

CAVALLERO, G., ., ; COUTO, A; LANDONI, M.

virtual

Congreso; Reunion Conjunta SAIB-SAMIGE; 2020

SAIB

Glycosylation is a significant protein post-translational modification. It is well-known that glycan moieties of many glycoproteins affect their biofunctions. Although different techniques have been used for glycoprotein characterization, nowadays, mass spectrometry has become the leading tool. While glycomics is focused on the characterization of the glycan structures regardless the sites where they are linked, glycoproteomics aims to define the micro and macroheterogeneities of glycoproteins as the MS/MS spectra of glycopeptides offer information of both, the peptide backbone and the oligosaccharide moiety. In this context, I will describe the glycoproteomic analysis of chicken egg white (CEW) performed in our lab. Previously, several proteomic studies on CEW proteins have been described and some glycomic studies of isolated egg white proteins and of the complex egg white have been reported. However, no detailed glycoproteomic studies on the whole egg white have been performed so far in order to simultaneously characterize the modified peptides along with their glycan moieties. In this work we have performed the analysis of the chicken egg white glycoproteins in a single experiment using a three-step workflow. This approach allowed us to characterize 19 glycoproteins. Among them, glycosylation sites and their linked glycan structures in 6 low abundant proteins were identified for the first time. The information obtained is profitable for a better understanding of the glycoprotein biological attributes as well as to establish an efficient methodology to characterize complex glycoprotein mixtures in different systems.