Chemical Glycoproteomics

Abstract

Chemical tools have accelerated progress in glycoscience, reducing experimental barriers to studying protein glycosylation, the most widespread and complex form of posttranslational modification. For example, chemical glycoproteomics technologies have enabled the identification of specific glycosylation sites and glycan structures that modulate protein function in a number of biological processes. This field is now entering a stage of logarithmic growth, during which chemical innovations combined with mass spectrometry advances could make it possible to fully characterize the human glycoproteome. In this review, we describe the important role that chemical glycoproteomics methods are playing in such efforts. We summarize developments in four key areas: enrichment of glycoproteins and glycopeptides from complex mixtures, emphasizing methods that exploit unique chemical properties of glycans or introduce unnatural functional groups through metabolic labeling and chemoenzymatic tagging; identification of sites of protein glycosylation; targeted glycoproteomics; and functional glycoproteomics, with a focus on probing interactions between glycoproteins and glycan-binding proteins. Our goal with this survey is to provide a foundation on which continued technological advancements can be made to promote further explorations of protein glycosylation.

Bioorthogonal Labeling of Human Prostate Cancer Tissue Slice Cultures for Glycoproteomics

“…[15] To target sialoglycoproteins specifically, cells are metabolically labeled with a modified peracetylated N -acetylmannosamine (Ac 4 ManNAc) analogue such as peracetylated N -azidoace-tylmannosamine (Ac 4 ManNAz, 1 ) [16] or its alkynyl counterpart, peracetylated N -pentynoylmannosamine (Ac 4 ManNAl). These compounds are converted by the Roseman–Warren pathway into the corresponding sialic acid derivatives, which are, in turn, incorporated into sialoglycoproteins.…”

Synthesis of rhamnosylated arginine glycopeptides and determination of the glycosidic linkage in bacterial elongation factor P

“…6,7 Importantly, the number of eukaryotic proteins known to be glycosylated has dramatically increased in recent years owing, in major part, to improvements in glycoproteomic mass spectrometry methodologies. 8–10 …”

Sensitive and robust MALDI-TOF-MS glycomics analysis enabled by Girard's reagent T on-target derivatization (GTOD) of reducing glycans

“…For purpose of improving MS detection sensitivity, many chemical derivatizations of free glycans have been developed to improve the detection sensitivity during MS analysis [24–26], including widely used permethylation [27], reductive amination with various type of hydrophobic aromatic amines [26], Michael's addiction with 1-phenyl-3-methyl-5-pyrazolone (PMP) [28] and acid catalyzed condensation with hydrazides or hydroxylamines to form hydrazones or oximes [29–32]. These derivatizations are usually applied to significant amounts of samples (μg to mg), often under relatively strong reaction conditions involving heating with acid or base.…”