UNVEILING THE PRESENCE OF O-GLYCOSYLATION IN DIFFERENT GLYCOPROTEINS PRESENT IN CHICKEN EGG WHITE

M LANDONI; MN RODRIGUEZ; COUTO AS

Food Bioscience

Elsevier BV

Año: 2024

2212-4292

Chicken egg white contains hundreds of proteins that are widely used in the food,biological and pharmaceutical industries. Glycosylation provides additional structuraldiversity to the already specialized proteins. The array of glycans on protein surfacesand different glycosylation sites provide sophisticated structures essentials for themultiple functions that glycoproteins assume.Different types of analysis have been performed to determine N-glycosylation inchicken egg white. In different studies, up to 19 N-glycoproteins have beencharacterized. However, regarding O-glycosylation, there is insufficientknowledge oftheir structures and abundances. In fact, only ovomucin, a major component of chickenegg white, has been described as bearing O-glycans that consist of 2?6 sugar residuescarrying sialic acid and/or sulfate groups.In the present work, the use of a reductive b-elimination reaction followed by a HPAECPADanalysis, showed released oligosaccharides suggesting the presence of differentO-glycoproteins.Getting deeper into chicken egg white O-glycoproteomics, ananoHPLC-ESI-Orbitrap-HCDanalysis was performed and two different software toolswereemployed. Under these conditions, at least seven different O-glycosylatedproteinswere described. In addition, O?glycosylation of isolated ovalbumin wascharacterizedfor the first time and in a BEMAD analysis of the isolated glycoprotein,threeO-glycosites were detected. Taking into account that glycosylation has beeninvolvedin the structure and properties of chicken egg white proteins such asallergenicity,antibacterial action and embryo protection, attention must be paid toexplorenew properties of this heterogeneous modification in relation to both the foodandbiopharmaceutical industries.