Updated project metadata. The most abundant and central component, glycoprotein C3, contributes to the development of type 1 diabetes by enhancing the organ-specific autoimmune inflammatory processes. It is known that changes in glycosylation can modulate inflammatory responses and we recently showed that children at the onset of type 1 diabetes have a higher proportion of oligomannose glycans in plasma N-glycome compared to their healthy siblings. Due to fact that C3 contains two N-glycosylation sites occupied by this type of glycans, our aim was to develop a novel high-throughput and cost-effective glycoproteomic workflow for N-glycosylation analysis of human C3 to reveal the possible role of C3 glycosylation in type 1 diabetes development.