Highly selective and ultra fast solid-phase extraction of N-glycoproteome by oxime click chemistry using aminooxy-functionalized magnetic nanoparticles.

For the highly efficient extraction of the N-glycoproteome, a novel solid-phase extraction method based on oxime click chemistry has been developed. With the use of a newly synthesized aminooxy-functionalized magnetic nanoparticle, the oxidized glycan chains on glycopeptides readily react with the aminooxy groups through oxime click chemistry, resulting in the highly selective extraction of glycopeptides. Compared to the traditional hydrazide chemistry-based method, which takes 12-16 h of coupling time, this new method renders excellent enrichment performance within 1 h. Furthermore, the enrichment sensitivity (fmol level), selectivity (extracting glycopeptides from mixtures of nonglycopeptides at a 1:100 molar ratio), and reproducibility (CVs < 20%) are also dramatically improved. We have successfully profiled the N-glycoproteome from only 1 μL of human colorectal cancer serum using this innovative protocol, which offers a more efficient alternative N-glycoproteome extraction method.