What’s New?

Read Our Latest Peer-Reviewed Paper!

09/03/2019

Glycosylation is a common modification found on numerous proteins and lipids. However, direct detection of glycans on these intact biomolecules has been challenge. Here, utilizing enzymatic incorporation of fluorophore-conjugated sialic acids, dubbed as Direct Fluorescent Glycan Labeling (DFGL), we report the labeling and detection of N- and O-glycans on glycoproteins. The method allows detection of specific glycans without the laborious gel blotting and chemiluminescence reactions used in Western blotting. The method can also be used with a variety of fluorescent dyes.

Read the Accepted Manuscript!

A Simple, User-Friendly Protocol for Fluorescence Imaging

07/01/2019

A major challenge to assessing the role of glycosylation in cellular function has been the lack of selective, easy-to-use reagents and assays. To address this issue, we have focused a great deal of effort on developing simple and accessible assays that all investigators can use to visualize terminal glycans. In order to drive this endeavor home, we have generated an easy to use protocol for visualizing O-GlcNAc in cultured cells. This assay does not require any expensive capital purchases. It can be completed using commonly available laboratory reagents. See how!

Download the O-GlcNAc AppNote!

Glycobiology White Paper

06/15/2019

Did you know that Bio-Techne scientists have advanced the Glycobiology field with many peer-reviewed scientific publications? The end-result of our research and development enterprise is a broad array of solutions designed to fulfill your glycobiology research and development needs. With that in mind, this white paper was written to summarize peer-reviewed glycobiology research by Bio-Techne scientists. Our aim was to provide a quick and user-friendly gateway to our science and assay development. From radioactive sulfation assays to fluorescent visualization of glycans in situ, our scientists have worked at the leading edge of glycobiology for nearly a decade. Learn more!

Download Our Glycobiology White Paper

Immune Checkpoint: The Importance of Glycosylation for PD-L1 mAb Efficacy

06/01/2019

Programmed death ligand 1 (PD-L1) and programmed death protein 1 (PD-1) are well known immune checkpoint targets for cancer. Several biologics have been approved by the Food and Drug Administration for the treatment of cancer including anti-PD-1 monoclonal antibodies (mAbs) (Keytruda, Opdivo, Libtayo), anti-PD-L1 mAbs (Tecentriq, Bavencio, Imfinzi) and the anti-CTLA-4 monoclonal antibody (Yervoy).  Although they have revolutionized cancer therapeutics, they are not effective in all contexts; thus, the imperative to maximize the efficacy of therapeutic mAbs. One approach to improve efficacy is to optimize the constant (Fc) region of the antibody. This region contains the site of N-glycosylation and is important for mediating antibody dependent cellular toxicity (ADCC).  As such, it can have a dramatic impact on the efficacy of immune checkpoint therapy. Goletz et al. (2018) assessed the impact of “Glyco-optimization” on anti PD-L1 (Tecentriq) efficacy.  They assessed the efficacy of PD-L1 variants that were non-glycosylated (Tecentriq) or N-glycosylated (and core fucosylated) or N-glycosylated (and defucosylated). Although antigen binding was identical in all mAbs, the defucosylated antibody exhibited increased binding to FCγIIIa receptors.  This variant was also correlated with increased NK cell mediated ADCC against a PDL-L1+ cancer cell line and increased CD8 T cell activation relative to the other variants. This paper highlights the critical importance of glycosylation assessment as part of the development workflow for mAbs as therapeutics. Bio-Techne’s Simple Western™ platform is ideal for high throughput glycan characterization.

Download our Simple Western AppNote

Download Appnote

Immunology: C-Terminal Glycosylation Regulates Perforin Activation and Synaptic Toxicity.

05/15/2019

Cytotoxic T Lymphocytes (CTLs) induce apoptosis in target cells via the activity of pore forming perforin proteins and granzyme serine proteases at the immunological synapse. Granzymes enter target cells via transmembrane pores formed by oligomers of the cytotoxic perforin protein. One of the important unanswered questions in the field of immunology is how CTLs regulate the activity of perforin prior to storage in secretory granules. House et al. (2017)recently published data indicating that C-terminal glycosylation precludes premature perforin activity in CTLs. Specifically, they demonstrated that high mannose N-glycosylation or complex N-glycosylation at asparagine 549 (Asn549) on the perforin C-terminus inhibits oligomerization and pore formation. This paper highlights the critical, yet oft-unappreciated role of glycosylation in the functioning immune system.  Furthermore, it also provides an excellent proof of concept of how glycoenzymes are a useful tool for assessing the role of glycosylation in biological function. Bio-Techne has the largest selection of high-quality R&D Systems glyco-enzymes on the market.

Glycobiology-related Enzymes

O-GlcNAcylation: A Complex Role in Immunology and Cancer

05/01/2019

A recent review by de Jesus et al. (2018) discussed the role of O-GlcNAcylation in immune cell function and cancer. This post-translational modification (PTM) is characterized by a rapid and transient cycling of O-GlcNAc on and off the hydroxy residues of serine or threonine acceptors. Glycan attachment and removal are catalyzed by the enzymes O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively. This PTM is active at the level of transcription, post-transcriptional, post translational cellular activity, and cellular signaling in several immune cell types, including neutrophils, B cells, T cells, natural killer cells, macrophages, and lymphoid or myeloid cancer cells. Of interest, O-GlcNAcylation has a role in leukemia oncogenesis. The inverse activity of OGA and OGT may serve to tune oncogenesis, which is enhanced when O-GlcNAcylation is suppressed and suppressed when O-GlcNAcylation is enhanced. Finally, a consistent theme in this review is how little we understand O-GlcNAcylation in this context. A major roadblock is “the limited availability of user-friendly, effective technology ideal for the detection of O-GlcNAcylation site(s) in target proteins.” Bio-Techne fills this void with the most selective and user-friendly tools for assessing O-GlcNAcylation on the market.

Visualize Terminal Glycans
OGA and OGT have reciprocal activity

Prion Biology: A Role for Glycosylation in Prion Protein Toxicity and Aggregation

04/15/2019

Transmissible Spongiform Encephalopathies (TSEs), are a collection of progressive and invariably fatal neurodegenerative diseases. As such, there is an imperative to mechanistically understand disease progression. TSEs, also known as prion diseases, are a consequence of the conversion of the normal prion protein (PrPc) to the misfolded prion protein (PrPsc). Prion diseases have been documented in rodents, cattle, and humans. Human PrP is a glycosylphosphatidylinositol (GPI) anchored glycoprotein with two C-terminal glycosylation sites, Asn-181 and Asn-197.  Given the role of glycosylation in protein folding and quality control, it is an obvious target for study.  Recently, Yi et al. (2018) published data indicating that PrP N-glycosylation plays an important role in PrP aggregation and cytotoxicity. Specifically, they observed altered PrP subcellular localization in cell lines expressing PrP N-glycosylation deficient mutants. They also observed increased proteinase K (PK) resistance and aggregation in unglycosylated mutants. Increased PK resistance is an important observation because PK resistance is a hallmark of the misfolded, infectious PrPsc. Finally, the authors observed increased cytotoxicity in the non-glycosylated PrP mutant. Taken together these data provide compelling evidence of the importance of glycosylation for PrP activity. Taken a step further, these data also suggest a potential target for therapeutic intervention. Looking for a way to automate prion glycosylation research? See how simple western is used in a PrPC degycosylation workflow

Learn More!

Neuroscience: Glycosylation and APP Processing and Trafficking

04/01/2019

The amyloid beta (Aβ) cascade hypothesis is the most prominent mechanistic description of the progression of Alzheimer's Disease (AD). According to this hypothesis, the deposition of Aβ is an early salient event that precedes several events, including the formation of neurofibrillary tangles (NFTs) in the brains of people with AD. The amyloidogenic beta amyloid (Aβ 1-42) is generated by the sequential cleavage of amyloid precursor protein (APP) by beta secretase and the gamma secretase protein complex. An incredible amount of effort has focused on the cellular trafficking of APP, beta secretase, and gamma secretase in order to understand how to preclude the secretion and deposition of Aβ. A review by Kizuka et al. (2018) summarizes what is known about the relationship between glycosylation and AD pathogenesis. Studies have shown that N-glycosylation and sialylation are important for APP transport and secretion. Glycosylation has also been shown to have an important role in the pace of beta secretase production.   Removal of N-glycans from the beta secretase-beta site APP cleaving enzyme 1 (BACE-1) has been shown to slow the maturation of the protein. Interestingly, BACE-1 itself was found to regulate glycosylation via its proteolytic action. Gamma secretase is a complex of four proteins including presenilin 1/2, nicastrin, anterior pharynx -defective-1, and presenilin enhancer 2. Although Nicastrin is the only N-glycosylated protein, at this point it isn’t clear what role glycosylation plays in nicastrin function. The activity of alpha secretases, a disintigrin and metalloprotease domain (ADAM) proteins, preclude the generation of the Aβ 1-42 as part of the non-amyloidogenic pathway. ADAM subcellular trafficking has been shown to be altered by mutation of the second of four N-glycan sites. Finally, NFTs are formed by the aggregation of the cytosolic Tau protein.  Although there is evidence that Tau N-glycosylation is altered in the context of AD, more studies are needed to confirm published findings. Taken together it is clear that we are only beginning to understand the role of glycosylation in the context of AD progression. Bio-Techne has the largest selection of high-quality of solutions for investigating the glycosylation of AD-related proteins.

Learn More

Imaging Cellular Glycan Epitopes and Glycoproteins Using Glycosyltransferases

12/15/2018

Glycans are basic molecules in all living organisms. However, they are not well characterized due to the unavailability of specific and high-sensitivity detection reagents. We describe here a method for enzyme-based glycan imaging using glycosyltransferases. Azido-sugars are incorporated into target glycans followed by click chemistry-based conjugation with fluorescent reporters. Since glycosyltransferases have well defined substrate specificities, this method offers precise detection of target glycans. Examples include imaging of O-GlcNAc, O-GalNAc (Tn antigen), T antigen, sialyllactosamine (sLN), hyaluronan (HA), and heparan sulfate epitopes in different cell lines. This highly specific technique will facilitate the detection and characterization of biologically important glycans.

Download the Poster!

A Sensitive Method for Probing Sialoglycans Using Azido- Sugars and Glycosyltransferases!

12/01/2018

We describe a novel technique for probing terminal glycans on glycoproteins. Our approach consists of in vitro incorporation of specially developed azido-monosaccharides and various recombinant glycosyltransferases and glycosidases, followed by detection via click chemistry and traditional chemiluminescence. The technique uses SDS-PAGE and protein transfer in a manner similar to Western blot. It is very specific and does not require expensive equipment such as mass spectrometry. To demonstrate its utility, we probed for both N- and O-linked sialoglycans. Using fetal bovine fetuin as an example, we demonstrated: (I) The non-reducing end Gal residues on both N-glycans and O-glycans on the protein are fully sialylated, while the O-linked GalNAc residues are not; (II) The protein contains abundant sialyl core-1 glycan; (III) The protein also contains sialyl Tn antigen. We also present a method for specifically probing high mannose glycans.

Download the Poster!

A Novel Method for Detecting Terminal Glycans Using SDS-Page.

11/15/2018

We have developed a novel technique capable of probing terminal monosaccharides on proteins using SDS-PAGE. This technique does not require expensive equipment and is more specific than comparable methods. Additionally, it offers any laboratory the ability to gain a greater understanding of the glycan profiles of their protein of interest without significant

Download the white paper!

Bio-Techne fills a Need for Simple Tools to Study Glycobiology

09/06/2018

Learn More!