Oligosaccharide Moieties Research Articles

Crosslinking ability of hydrolyzed distarch phosphate and its stabilizing effect on rehydrated sea cucumber

Effective crosslinking among food constituents has the potential to enhance their overall quality. Distarch phosphate (DSP), a common food additive employed as a thickening agent, bears a pre-crosslinked oligosaccharide (PCO) moiety within its molecular structure. Once this moiety is released, its double reducing end has the potential to undergo crosslinking with amino-rich macromolecules through Maillard reaction. In this study, hydrolyzed distarch phosphate (HDSP) was synthesized, and spectroscopic analysis verified the presence of PCO within HDSP. Preliminary validation experiment showed that HDSP could crosslink chitosan to form a hydrogel and significant browning was also observed during the process. Furthermore, rehydrated sea cucumber (RSC) crosslinked with HDSP exhibited a more intact appearance, higher mechanical strength, better color profile, and increased water-holding capacity. This series of results have confirmed that HDSP is capable to crosslink amino-rich macromolecules and form more stable three-dimensional network.

Effect of Tetrahydrocurcumin Compared to Curcumin in Carbohydrate Metabolism and Glycoprotein Components in Type 2 Diabetes - Systematic Review

Pancreatic β-cell dysfunction and insulin resistance are the two hallmarks of type 2 diabetes mellitus. Treatment of diabetes without any side effects is still a challenge to the medical system. There is an increasing demand by patients to use the natural products with antidiabetic activity, because insulin and oral hypoglycemic drugs are having so many side effects. Curcumin is a biologically active component isolated from the rhizome of Curcuma longa that possess antidiabetic and has been proven scientifically to possess high antioxidant activity and anticancer properties. Tetrahydrocurcumin (THC) is a major curcuminoid metabolite of curcumin, naturally occurring in turmeric. The interest in THC research is increasing because it is superior to curcumin in its solubility in water, chemical stability, bioavailability, and anti-oxidative activity. Many in vitro and in vivo studies have revealed that THC exerts antidiabetic effects through various mechanisms, including modulation of oxidative stress, xenobiotic detoxification, inflammation, proliferation, metastasis, programmed cell death, and immunity. The activities of glycolytic enzymes such as hexokinase and glucose-6-phosphate dehydrogenase were found to be decreased whereas the activities of gluconeogenic enzymes (glucose-6-phosphatase and fructose-1,6-bisphosphatase) and polyol pathway enzyme-sorbitol dehydrogenase were significantly increased in diabetic control rats. In addition, the oligosaccharide moieties of glycoproteins (hexose, hexosamine, fucose and sialic acid) were also significantly increased in plasma and tissues of diabetic control rats. THC and curcumin administration to diabetic rats significantly reversed the above changes when compared to diabetic control rats. In diabetic controls, hepatic and skeletal muscle glycogen content was decreased significantly as compared to non-diabetic controls. Treatment with THC and curcumin increased the hepatic and skeletal muscle glycogen significantly. The antidiabetic and antioxidant effects of THC are more potent than those of curcumin at the same dose. The antihyperglycemic action of THC might be mediated via an enhancement of insulin action, as it is evidenced by the increased levels of insulin in diabetic rats treated with THC, which may be responsible for the reversal of changes in carbohydrate enzymes and glycoprotein components. The THC administration showed more effective than curcumin.

Bladder Cancer Cells Interaction with Lectin-Coated Surfaces under Static and Flow Conditions.

Aberrant expression of glycans, i.e., oligosaccharide moiety covalently attached to proteins or lipids, is characteristic of various cancers, including urothelial ones. The binding of lectins to glycans is classified as molecular recognition, which makes lectins a strong tool for understanding their role in developing diseases. Here, we present a quantitative approach to tracing glycan-lectin interactions in cells, from the initial to the steady phase of adhesion. The cell adhesion was measured between urothelial cell lines (non-malignant HCV29 and carcinoma HT1376 and T24 cells) and lectin-coated surfaces. Depending on the timescale, single-cell force spectroscopy, and adhesion assays conducted in static and flow conditions were applied. The obtained results reveal that the adhesion of urothelial cells to two specific lectins, i.e., phytohemagglutinin-L and wheat germ agglutinin, was specific and selective. Thus, these lectins can be applied to selectively capture, identify, and differentiate between cancer types in a label-free manner. These results open up the possibility of designing lectin-based biosensors for diagnostic or prognostic purposes and developing strategies for drug delivery that could target cancer-associated glycans.

Cytotoxic Steroidal Saponins Containing a Rare Fructosyl from the Rhizomes of Paris polyphylla var. latifolia.

A phytochemical investigation of the steroidal saponins from the rhizomes of Paris polyohylla var. latifolia led to the discovery and characterization of three new spirostanol saponins, papolatiosides A-C (1-3), and nine known compounds (4-12). Their structures were established via extensive spectroscopic data analysis and chemical methods. Interestingly, compounds 1 and 2 possessed a fructosyl in their oligosaccharide moiety, which is rare in natural product and was firstly reported in family Melanthiaceae. The cytotoxicity of these saponins against several human cancer cell lines was evaluated by a CCK-8 experiment. As a result, compound 1 exhibited a significant cytotoxic effect on LN229, U251, Capan-2, HeLa, and HepG2 cancer cells with IC50 values of 4.18 ± 0.31, 3.85 ± 0.44, 3.26 ± 0.34, 3.30 ± 0.38 and 4.32 ± 0.51 μM, respectively. In addition, the result of flow cytometry analysis indicated that compound 1 could induce apoptosis of glioma cells LN229. The underlying mechanism was explored by network pharmacology and western bolt experiments, which indicated that compound 1 could induce glioma cells LN229 apoptosis by regulating the EGFR/PI3K/Akt/mTOR pathway.

PERIODIC MESOPOROUS ORGANOSILICAS WITH CHEMICALLY IMMOBILIZED β CYCLODEXTRIN MOIETIES FOR BILE SALTS SORPTION

Mesoporous silicas of MCM‑41 type with surface silanol, 3-aminopropyl, and β‑cyclo­dextrin‑containing groups were prepared by hydrothermal‑assisted base‑catalyzed sol‑gel condensation of structure-forming silanes in the presence of micelles of long‑chain quaternary ammonium salt. Characterization of synthesized silica materials was realized by low‑tempe­rature nitrogen adsorption‑desorption and chemical analysis of surface layer. It was found that addition of ‑cyclodextrin‑containing silane into the sol‑gel reaction mixture causes formation of MCM‑41‑type organosilica with higher surface area and hexagonally arranged uniform mesoporous structure. Sorption ability of synthesized silica materials towards sodium cholate and sodium taurocholate was studied in dependence of solution pH and concentration. It was found that sorption increases due to chemical immobilization of oligosaccharide moieties in the surface layer of silica, and achieves maximal values in the pH regions of molecular forms of bile acids prevailing. Experimental sorption results were analyzed using Freundlich, Redlich - Peterson, and Brunauer - Emmett - Teller models. The formation of island-type structures of bile salts with β‑cyclodextrin-containing surface sorption centers due to cooperative interactions between sorbate moieties was proved.

Use of a Longer Aglycon Moiety Bearing Sialyl α(2→3) Lactoside on the Glycopolymer for Lectin Evaluation.

A polymerizable alcohol having 9 PEG repeats was prepared in order to mimic an oligosaccharide moiety. Sialyl α(2→3) lactose, which is known as a sugar moiety of GM3 ganglioside, was also prepared, and the polymerizable alcohol was condensed with the sialyl α(2→3) lactose derivative to afford the desired glycomonomer, which was further polymerized with or without acrylamide to give water-soluble glycopolymers. The glycopolymers had higher affinities than those of glycopolymers having sialyl lactose moieties with shorter aglycon moieties.

NMR and MD Simulations Reveal the Impact of the V23D Mutation on the Function of Yeast Oligosaccharyltransferase Subunit Ost4

Oligosaccharyl transferase (OST) is a multi-subunit enzyme that catalyzes the co-translational N-glycosylation of nascent polypeptides in the endoplasmic reticulum (ER). In the case of Saccharomyces cerevisiae, OST is composed of nine non-identical transmembrane protein subunits. In the central step of N-glycosylation, a preassembled oligosaccharide moiety is transferred to the asparagine side chain located in the Asn-X-Ser/Thr consensus sequence of the newly synthesized polypeptide chain in the lumen of the endoplasmic reticulum (ER). Defects in N-glycosylation pathway can cause disorders known as congenital disorders of glycosylation (CDG) that includes but not limited to mental retardation, developmental delay, dysmorphic features, etc. Complete loss of N-glycosylation is lethal in organisms. Due to the inherent difficulties associated with integral membrane protein studies, the enzymatic mechanism of OST function remains obscure, although prior mutagenesis results indicate that the smallest subunit, Ost4 stabilizes the catalytic subunit, Stt3. The structural and functional characterization of Ost4 subunit and its functionally important mutant, Ost4V23D using NMR and molecular dynamics simulations will be presented. Our data demonstrate that although Ost4 and Ost4V23D have very similar 3D structures, however, the mutation disrupted most of the hydrophobic helix-helix interactions between the mutant protein and TM 12 and TM 13 of Stt3. This disengagement of Ost4V23D from the OST complex led to solvent exposure of the D23 residue in the hydrophobic pocket created by these interactions. 1. Amit Kumar*, Priscilla Ward, Uma Katre and Smita Mohanty, A Novel Method of Production and Biophysical Characterization of a Mini-Membrane protein, Ost4p: A Subunit of Yeast Oligosaccharyl Transferase, Biopolymers, 97, 499-507, (2012). 2. Bharat P Chaudhary, David L Zoetewey, Martin J McCullagh, and Smita Mohanty, NMR and MD simulations Reveal the Impact of the V23D mutation on the Function of the Yeast Oligosaccharyltransferase Subunit Ost4, 2021, DOI: 10.1093/glycob/cwab002.

A Modular Chemoenzymatic Synthesis of Disialosyl Globopentaosylceramide (DSGb5Cer) Glycan.

The total synthesis of the oligosaccharide moiety of disialosyl globopentaosylceramide (DSGb5 Cer), a dominant ganglioside isolated from malignant renal cell carcinoma tissues, is reported. The synthetic strategy relies on a chemical α(2,6)-sialylation at the internal GalNAc unit of a Gb5 pentasaccharide backbone that furnishes a Neu5Acα(2,6)GalNAc-linked hexasaccharide, suitable for an enzymatic α(2,3)-sialylation of the terminal Gal residue to construct a heptasaccharide glycan. Convergent access to this key α(2,6)-sialylated hexasaccharide was also achieved through a [3+3] glycosylation building upon a Galβ(1,3)[Neu5Acα(2,6)]GalNAc-based trisaccharide donor and a Gb3 acceptor. The synthetic DSGb5 glycan bearing a 6-azidohexyl aglycon at the reducing end could undergo further regioselective functionalization. This approach represents a viable chemoenzymatic method for accessing complex ganglioside glycans and should be useful for the synthesis and biological investigation of DSGb5 derivatives.

Triterpene glycosides from Blighia welwitschii and evaluation of their antibody recognition capacity in multiple sclerosis

Multiple sclerosis (MS) in a multifactorial autoimmune disease in which reliable biomarkers are needed for therapeutic monitoring and diagnosis. Autoantibodies (autoAbs) are known biomarker candidates although their detection in biological fluids requires a thorough characterization of their associated antigens. Over the past twenty years, a reverse chemical-based approach aiming to screen putative autoantigens has underlined the role of glycans, in particular glucose, in MS. Despite the progress achieved, a lack of consensus regarding the nature of innate antigens as well as difficulties proposing new synthetic glucose-based structures have proved to be obstacles. Here is proposed a strategy to extend the current methodology to the field of natural glycosides, in order to dramatically increase the diversity of glycans that could be tested. Triterpene saponins from the Sapindaceace family represent an optimal starting material as their abundant description in the literature has revealed a prevalence of glucose-based oligosaccharides. Blighia welwitschii (Sapindaceae) was thus selected as a case study and twelve triterpene saponins were isolated and characterized. Their structures were elucidated on the basis of 1D and 2D NMR as well as mass spectrometry, revealing seven undescribed compounds. A selection of natural glycosides exhibiting various oligosaccharide moieties were then tested as antigens in enzyme-linked immunosorbent assay (ELISA) to recognize IgM antibodies (Abs) in MS patients’ sera. Immunoassay results indicated a correlation between the glycan structures and their antibody recognition capacity, allowing the determination of structure-activity relationships that were coherent with previous studies. This approach might help to identify sugar epitopes putatively involved in MS pathogenesis, which remains poorly understood.

In Silico Target Identification and Molecular Docking Studies of Natural Cytotoxic Compound Borivilianoside H

Background: Borivilianoside H is a naturally occurring anti-cancer compound with known cytotoxicity against human colorectal cancer cell line (HCT-116) and human adenocarcinoma cell line (HT-29). The present study describes the pharmacophore modelling, molecular docking, and molecular dynamics simulation approaches to predict the target proteins of borivilianoside H along with its binding affinity to the selected proteins. Methods: A 3-dimensional structure of borivilianoside H was constructed using Avogadro from its 2-D coordinates retrieved from the Pubchem Compound database. Target proteins associated with cancers were identified based on the 95% normalized fit score of PharmMapper. The crystal structures of the targets were retrieved from Protein Data Bank and molecular docking was performed with Autodock Vina 1.1.2. MD simulations were carried out via Google Cloud Platform. ADMET characteristics for borivilianoside H were determined using admetSAR web server. Results: Among the selected 7 top-ranked target proteins, fibroblast activation protein (FAP) exhibited the highest binding affinity followed by serum albumin (ALB), bone morphogenetic protein 2 (BMP2) and kinesin-like protein 11 (KIF11). However, the best fit was found with KIF11, where both the steroidal and oligosaccharide moieties of borivilianoside H were involved in interacting with the protein cavity. KIF11 was thus found to be the most suitable target for the anti-cancer effect of borivilianoside. ADMET analysis revealed its suitability as an intravenous drug. Conclusions: The targets predicted using this approach will serve as leads for the possible use of borivilianoside H, one of the active ingredients of Chlorophytum borivilianum as an anti-cancer drug.

Glucose Transport and Transporters in the Endomembranes.

Glucose is a basic nutrient in most of the creatures; its transport through biological membranes is an absolute requirement of life. This role is fulfilled by glucose transporters, mediating the transport of glucose by facilitated diffusion or by secondary active transport. GLUT (glucose transporter) or SLC2A (Solute carrier 2A) families represent the main glucose transporters in mammalian cells, originally described as plasma membrane transporters. Glucose transport through intracellular membranes has not been elucidated yet; however, glucose is formed in the lumen of various organelles. The glucose-6-phosphatase system catalyzing the last common step of gluconeogenesis and glycogenolysis generates glucose within the lumen of the endoplasmic reticulum. Posttranslational processing of the oligosaccharide moiety of glycoproteins also results in intraluminal glucose formation in the endoplasmic reticulum (ER) and Golgi. Autophagic degradation of polysaccharides, glycoproteins, and glycolipids leads to glucose accumulation in lysosomes. Despite the obvious necessity, the mechanism of glucose transport and the molecular nature of mediating proteins in the endomembranes have been hardly elucidated for the last few years. However, recent studies revealed the intracellular localization and functional features of some glucose transporters; the aim of the present paper was to summarize the collected knowledge.

Structure of an endogalactosylceramidase from Rhodococcus hoagii 103S reveals the molecular basis of its substrate specificity

Endoglycoceramidases (EGCs) are family 5 glycoside hydrolases that catalyze hydrolysis of the glycosidic linkages between the oligosaccharide and ceramide moieties of glycosphingolipids. Three orthologs of EGCs, each with distinct substrate specificity, have been identified to date, including EGC-I, EGC-II, and EGALC. Although the structures of EGC-I and EGC-II have been reported, the substrate preference mechanism of EGC enzymes remains unclear. Here, we determined the crystal structure of EGALC from Rhodococcus hoagii 103S at a resolution of 1.20 Å. Distinct from EGC-I and EGC-II, which both have a tunnel-like substrate binding site, the structure of EGALC accommodates substrates in a long groove. Further, the oligosaccharide-binding region of groove could be divided into two small pockets that separately bind to the Gal1 and to the Gal3/Gla3 present in 6-gala series substrates. Structural and sequence comparisons of EGC enzymes revealed that the conformation and length of their Nβ8-Lα1 regions are crucial in determining the architectures of their specific substrate binding sites. Importantly, molecular docking analyses indicate that the substrate specificity of each EGC is mainly derived from the complementarity of its active site groove/tunnel with substrates adopting particular conformations. Our study provide insights for understanding the catalytic mechanism of EGALC, which will help protein engineering for improving the substrate preference and catalytic efficiency of EGC enzymes toward important glycosphingolipid substrates.

Gangliosides interact with synaptotagmin to form the high-affinity receptor complex for botulinum neurotoxin B

Botulinum neurotoxin type B (BoNT/B) recognizes nerve terminals by binding to 2 receptor components: a polysialoganglioside, predominantly GT1b, and synaptotagmin 1/2. It is widely thought that BoNT/B initially binds to GT1b then diffuses in the plane of the membrane to interact with synaptotagmin. We have addressed the hypothesis that a GT1b-synaptotagmin cis complex forms the BoNT/B receptor. We identified a consensus glycosphingolipid-binding motif in the extracellular juxtamembrane domain of synaptotagmins 1/2 and confirmed by Langmuir monolayer, surface plasmon resonance, and circular dichroism that GT1b interacts with synaptotagmin peptides containing this sequence, inducing α-helical structure. Molecular modeling and tryptophan fluorescence spectroscopy were consistent with the intertwining of GT1b and synaptotagmin, involving cis interactions between the oligosaccharide and ceramide moieties of GT1b and the juxtamembrane and transmembrane domains of synaptotagmin, respectively. Furthermore, a point mutation on synaptotagmin, located outside of the BoNT/B-binding segment, inhibited GT1b binding and blocked GT1b-induced potentiation of BoNT/B binding to synaptotagmin-expressing cells. Our findings are consistent with a model in which a preassembled GT1b-synaptotagmin complex constitutes the high-affinity BoNT/B receptor.

The crystal structure of the β subunit of luteinizing hormone and a model for the intact hormone.

The β subunit of bovine luteinizing hormone (LH) was crystallized and its structure solved to 3.15 ​Å resolution by molecular replacement using human chorionic gonadotropin (hCG) β subunit as search model. The asymmetric unit contains two copies of the β subunit that are related by a non-crystallographic symmetry (NCS) two-fold axis, both copies of which contain proteolytic cleavages after amino acid 100. It is noteworthy that the oligosaccharide moieties covalently attached at asparagine 13 were particularly pronounced in the electron density, allowing seven sugar residues to be defined. The α subunit of LH, which is common to all glycosylated gonadotropin hormones, was placed by superposition of hCG on the LH beta subunits, thereby yielding a model for the intact hormone.

Mucins: the Old, the New and the Promising Factors in Hepatobiliary Carcinogenesis.

Mucins are large O-glycoproteins with high carbohydrate content and marked diversity in both the apoprotein and the oligosaccharide moieties. All three mucin types, trans-membrane (e.g., MUC1, MUC4, MUC16), secreted (gel-forming) (e.g., MUC2, MUC5AC, MUC6) and soluble (non-gel-forming) (e.g., MUC7, MUC8, MUC9, MUC20), are critical in maintaining cellular functions, particularly those of epithelial surfaces. Their aberrant expression and/or altered subcellular localization is a factor of tumour growth and apoptosis induced by oxidative stress and several anti-cancer agents. Abnormal expression of mucins was observed in human carcinomas that arise in various gastrointestinal organs. It was widely believed that hepatocellular carcinoma (HCC) does not produce mucins, whereas cholangiocarcinoma (CC) or combined HCC-CC may produce these glycoproteins. However, a growing number of reports shows that mucins can be produced by HCC cells that do not exhibit or are yet to undergo, morphological differentiation to biliary phenotypes. Evaluation of mucin expression levels in precursors and early lesions of CC, as well as other types of primary liver cancer (PLC), conducted in in vitro and in vivo models, allowed to discover the mechanisms of their action, as well as their participation in the most important signalling pathways of liver cystogenesis and carcinogenesis. Analysis of mucin expression in PLC has both basic research and clinical value. Mucins may act as oncogenes and tumour-promoting (e.g., MUC1, MUC13), and/or tumour-suppressing factors (e.g., MUC15). Given their role in promoting PLC progression, both classic (MUC1, MUC2, MUC4, MUC5AC, MUC6) and currently tested mucins (e.g., MUC13, MUC15, MUC16) have been proposed to be important diagnostic and prognostic markers. The purpose of this review was to summarize and update the role of classic and currently tested mucins in pathogenesis of PLC, with explaining the mechanisms of their action in HCC carcinogenesis. It also focuses on determination of the diagnostic and prognostic role of these glycoproteins in PLC, especially focusing on HCC, CC and other hepatic tumours with- and without biliary differentiation.

Chemoenzymatic synthesis of the oligosaccharide moiety of the tumor-associated antigen disialosyl globopentaosylceramide.

Disialosyl globopentaosylceramide (DSGb5) is often expressed by renal cell carcinomas. To investigate properties of DSGb5, we have prepared its oligosaccharide moiety by chemically synthesizing Gb5 which was enzymatically sialylated using the mammalian sialyltransferases ST3Gal1 and ST6GalNAc5. Glycan microarray binding studies indicate that Siglec-7 does not recognize DSGb5, and preferentially binds Neu5Acα(2,8)Neu5Ac containing glycans.

User-friendly extraction and multistage tandem mass spectrometry based analysis of lipid-linked oligosaccharides in microalgae

BackgroundProtein N-glycosylation is initiated within the endoplasmic reticulum through the synthesis of a lipid-linked oligosaccharides (LLO) precursor. This precursor is then transferred en bloc on neo-synthesized proteins through the action of the oligosaccharyltransferase giving birth to glycoproteins. The N-linked glycans bore by the glycoproteins are then processed into oligomannosides prior to the exit of the glycoproteins from the endoplasmic reticulum and its entrance into the Golgi apparatus. In this compartment, the N-linked glycans are further maturated in complex type N-glycans. This process has been well studied in a lot of eukaryotes including higher plants. In contrast, little information regarding the LLO precursor and synthesis of N-linked glycans is available in microalgae.MethodsIn this report, a user-friendly extraction method combining microsomal enrichment and solvent extractions followed by purification steps is described. This strategy is aiming to extract LLO precursor from microalgae. Then, the oligosaccharide moiety released from the extracted LLO were analyzed by multistage tandem mass spectrometry in two models of microalgae namely the green microalgae, Chlamydomonas reinhardtii and the diatom, Phaeodactylum tricornutum.ResultsThe validity of the developed method was confirmed by the analysis of the oligosaccharide structures released from the LLO of two xylosyltransferase mutants of C. reinhardtii confirming that this green microalga synthesizes a linear Glc3Man5GlcNAc2 identical to the one of the wild-type cells. In contrast, the analysis of the oligosaccharide released from the LLO of the diatom P. tricornutum demonstrated for the first time a Glc2Man9GlcNAc2 structure.ConclusionThe method described in this article allows the fast, non-radioactive and reliable multistage tandem mass spectrometry characterization of oligosaccharides released from LLO of microalgae including the ones belonging to the Phaeodactylaceae and Chlorophyceae classes, respectively. The method is fully adaptable for extracting and characterizing the LLO oligosaccharide moiety from microalgae belonging to other phyla.

Purification and Partial Characterization of Melanoidins Fractions from Toasted Oak Heartwood, Comparison with Melanoidins from Roasted Coffee

During the cooking, processing, and storage of food products, a whole range of browning reactions occurs, initiated by the reaction of a carbohydrate with a compound possessing a free amino group. Melanoidins formed, influence food quality, mainly their colour, their flavour, and their antioxidant activities. Melanoidins are complex Maillard reaction products. We developed a method to isolate coffee melanoidins and melanoidins from toasted oak wood. We noted that coffee is richer in melanoidin compounds than oak wood. We presented a partial characterization of melanoidins fractions from toasted oak heartwood, and a comparison with melanoidins from roasted coffee. Mass spectra of the fractions isolated from toasted oak wood indicate the presence of pentose and hexose-based oligosaccharides with different degrees of polymerisation. The presence of the oligosaccharide moieties, as well as their degradation products found in the oak wood melanoidins, supports the postulated carbohydrate-based origin of melanoidins.

International Investigative Dermatology 2018 Meeting: Promoting Global Skin Biology and Skin Disease Research

International Investigative Dermatology 2018 Meeting: Promoting Global Skin Biology and Skin Disease Research

Glycomics and Cardiovascular Disease

Advances in high-dimensional molecular methods have opened the door to new efforts to personalize care for patients with cardiovascular disease (CVD). Such approaches have included efforts to better characterize the functional diversity of disease-related genes and proteins in states closer to the phenotype. For example, at the genetic level, epigenetic modifications, such as methylation and histone modification, can act to selectively regulate recognition and resultant function of the ≈20 000 genes in the human body. Similarly, at the protein level, post-translational modifications, such as glycosylation, acetylation, phosphorylation, methylation, and ubiquitination, increase the functional diversity of the corresponding complement of canonical proteins in the human body. Glycosylation represents one of the most important and complex of these post-translational regulatory mechanisms and involves the enzymatic attachment of oligosaccharide (sugar) moieties to proteins, in turn regulating protein function, folding, localization, and stability.1 These oligosaccharide chains are built from conserved components, including galactose, fucose, mannose, N-acetylglucosamine (GlcNAc), and sialic acid, in permutations that mediate numerous fundamental biological processes, including cell trafficking, metabolic control, signal transduction, and host pathogen recognition. Common human glycan attachments are N linked (attached to a protein’s amide nitrogen on an asparagine residue) or O linked (attached to a protein’s oxygen atom on a serine or threonine residue). As opposed to conventionally quantifying total protein concentrations in relation to disease, examining protein glycosylation states could enable a more precise interrogation of protein–disease relationships. Such observations could be used to identify more individualized risk markers and—particularly when the functional …