Characterization of disease-associated N-linked glycoproteins

Abstract

N-linked glycoproteins play important roles in biological processes, including cell-to-cell recognition, growth, differentiation, and programmed cell death. Specific N-linked glycoprotein changes are associated with disease progression and identification of these N-linked glycoproteins has potential for use in disease diagnosis, prognosis, and prediction of treatments. In this review, we summarize common strategies for N-linked glycoprotein characterization and applications of these strategies to identification of glycoprotein changes associated with disease states. We also review the N-linked glycoproteins altered in diseases such as breast cancer, lung cancer, and prostate cancer. Although assays for these glycoproteins have potential clinical utility, research is needed to translate these glycoproteins to clinical biomarkers.

Figure 1

Experimental workflow of analysis of cell-surface sialoglycoproteins using click chemistry. (1) Metabolic labeling of cells with peracetylated azidomannose (AC4ManNAz). (2) Chemoselective conjugation of azido sugars with a biotinylated alkyne capture reagent via Cu (I)-catalyzed click chemistry. (3) Lysis of labeled cells. (4) Affinity purification using streptavidin (SAv) resins. (5) Elution of captured sialoglycoproteins. (6) SDS-PAGE separation of sialoglycoproteins. (7) Isolation of gel slices and subsequent digestion and release of peptides. (8) Analysis of peptides by LC-MS/MS. (9) Bioinformatic analysis.