Services & Fees
|Service||Internal Rate||External Rate|
|Glycan Microarray Analysis||$195||$302|
|Unassisted Equipment use|
|Unassisted Equipment - MALDI||$105||$163|
|Unassisted Equipment - BiaCore||$30||$47|
|Unassisted Equipment - AutoITC||$35||$54|
|Unassisted Equipment - Workstation||$10||$16|
|Unassisted Equipment - Scanner||$25||$39|
The primary expertise of the Emory Comprehensive Glycomics Core (ECGC) is Functional Glycomics, which will focus on the application of glycan microarrays to understand the structure-function relationships of glycans through the study of protein-glycan interactions.
Analysis of Glycan Binding Proteins (GBP) on the Consortium for Functional Glycomics array of 610 defined glycans.
For a description of this resources see: http://www.functionalglycomics.org.
The ECGC will assist Emory Investigators with making requests for this resource, which is now located in the National Center for Functional Glycomics at Harvard Medical School in Boston. ECGC will also assist in interpretation of data using bioinformatic software developed at Emory.
Analysis of glycan binding proteins and viruses on an array of sialylated oligosaccharides
This glycan microarray is comprised of approximately 50 sialylated oligosaccharides containing the major ganglioside glycans and a variety of other sialic acid-containing glycans from natural sources. The slides are produced in the ECGC in collaboration with the NCFG in Boston, and ECGC staff can carry out assays using your GBP or organism(s).
Chemical Release of glycans from glycoconjugates
The release of free glycans from glycoconjugates is used for many glycomic analyses. This process has classically been carried out using harsh chemical processes such as hydrazinolysis to release N-glycans or strong base degradation to release O-glycans from glycoproteins. Glycolipid oligosaccharides can be released using ozonolysis followed by strong base. The harsh chemical conditions sometimes result in further degradation of the released glycans. We recently developed a proprietary process for chemically releasing glycans from glycoconjugates using controlled oxidation (manuscript in review). This process rapidly releases glycans and glycan derivatives from all glycoconjugates simultaneously, and the non-degraded glycans can be isolated from the supernatant of the chemically treated homogenate. Since the mechanism of release is different for each glycosidic linkage, the source of the resulting glycans can be identified based on the nature of the reducing end. This process is being developed for microscale analysis of glycoconjugates; however, this process is also useful for obtaining large quantities of N- and O-linked glycans and glycolipid-derived glycans from tissues, organs, or other biological samples, because we can use milligram to kilogram quantities of starting material.
Production of Tagged Glycan Libraries
Released glycans have a functional group at their reducing ends in the form of an aldehyde, a nitrile, or a carboxyl group. We have developed many methods to attach a variety of bi-functional fluorescent tags to the reducing ends of glycans. The tagged glycans with fluorescence and a primary amino group can be purified by multi-dimensional HPLC to tagged glycan libraries (TGLs). The TGLs can be stored for later retrieval, immobilized onto solid surfaces such as glycan microarray for functional, and subsequently structurally analyzed by mass spectrometry (MS).
Glycomic approaches to understanding the relationship between glycan structure and function have classically focused on determining the structures of N-, O- and glycolipid-linked glycans. However, listing and cataloging structures, like collecting stamps, has really provided little information regarding the function of glycans. Since the functions of glycans are thought in large part to involve protein-glycan interactions, we have utilized our unique chemistries to address Functional Glycomics by investigation protein-glycan interactions. Immobilizing glycans to solid phases is the first step in this process, and subsequent analyses involving the binding of protein, cells, microorganisms or other species that bind glycans are relatively simple and include detection of labeled organisms or glycan binding molecules, FACS analysis of glycan coated beads, and pull down experiments to identify unknown glycan binging proteins that can be identified by proteomic analyses
Production and Analysis of Glycan Microarray (Shotgun Glycan Microarrays)
We have had over 10 years of experience printing glycans as microarrays on microscope slides (see references at http://www.cores.emory.edu/ecgc/publications/index.html) that can subsequently be interrogated with fluorescently labeled glycan binding molecules and microorganisms. These glycans can be structurally defined glycans where the data support interpretation of the probably glycan binding specificity of the binding proteins. On the other hand, the glycans can be arrays of tagged glycan libraries (TGL) that we call Shotgun Glycan Microarrays (SGM) where any glycome may be interrogated using your suspected glycan binding protein or microorganism to identify physiologically relevant glycans that can retrieved from the TGL for more detailed structural analyses. Such studies are currently being carried out on SGM prepared from human milk oligosaccharides (see references at http://www.cores.emory.edu/ecgc/publications/index.html). Shotgun Glycan Microarrays represent significant investments, but can be made available in perpetuity for the scientific community through the ECGC and NCFG in Boston.
Custom Microarray Printing:
As the national Institutes of Health continues to encourage research in the area of glycomics through its Common Fund support for organic synthesis of glycans and generation of glycans from biological sources through chemical release of glycans and other newly developed amplification processes, glycans are becoming more and more available to the research community, and having glycans available and immobilized as microarrays on glass slides or on plastic and magnetic beads represent important resources that the ECGC can make available to the Emory and Atlanta Area scientific community. This is accomplished using two contact printers that we have available in the ECGC.
In addition to glycans, our printers are capable of printing microarrays of proteins and polysaccharides to generate high throughput immunoassays on microarrays or in 96-well plate formats where many proteins or polysaccharides can be printed in single microtiter plate wells.
Microarray analysis of custom microarrays
We are also equipped to analyze these custom arrays based on our many years of experience analyzing defined, as well as, shotgun glycan microarrays.
Protein-Glycan, Protein-Protein, or Protein-Small Molecule Interactions:
Real-time label-free monitoring of macromolecular interactions
Biacore™ and MicroCal™ systems from GE Life Sciences both utilize label-free detection technologies to study binding interactions.
Surface Plasmon Resonance – Biacore sytems are used in cancer research to evaluate and rank potential drug or diagnostic targets, to optimize new antibodies, affibodies, small peptides, or even small molecules for ideal binding, and to characterize protein-glycan interactions. Determining association and dissociation rates in addition to equilibrium constants provides greater insight into structure-function relationships. Biacore system sensorgrams show in real-time how fast the binding and dissociation takes place. Equations can than be fitted to the resulting curve to calculate on rates, off rates, and affinities. The ECGC is equipped with a GE Healthcare BiaCore X100, which can monitor molecular interaction by Surface Plasmon Resonance. This technology can be provided either as a service or as access to the equipment on an hourly or daily basis. For more detailed information see: www.gelifesciences.com/biacore.
Isothermal Titration Calorimetry – With MicroCal systems, molecular interactions can be investigated with isothermal titration calorimetry (ITC) to determine affinity and thermodynamic properties such as enthalpy, entropy, and Gibbs free energy. These factors help us to understand whether interactions are based on hydrophilic events, van der Waal interactions, or hydrophobicity. In cancer research, this can be used to rationally optimize drug structure. The ECGC is equipped with a GE Healthcare MicroCal Auto-iTC200 system, which provides detailed insight into binding energetics. The isothermal Titration Calorimeter (ITC) mixes the binding partners and monitors the heat changes by measuring the power required to maintain zero temperature difference between the reference and sample cells. This technology can be provided either as a service or as access to the equipment on an hourly or daily basis. For more detailed information see: http://www.malvern.com/en/products/product-range/microcal-range/default.aspx.
Glycomic analysis by Mass Spectrometry
Profiling the molecular masses of glycans in mixtures released from purified glycoprotein, mucins, glycolipids, as well as cultured cells, tissues, or organs can generate compositional information on glycans that can provide predictions of structures, which is known as Glycomic Profiling. This can be carried out by ECGC personnel using the ECGC’s Bruker UltraFlex II MALDI – TOF/TOF mass Spectrometer. In addition the Comprehensive Glycomics Core can provide access to this instrument at an hourly rate for your glycomic or proteomic analyses.
Detailed analysis of glycans by a variety of techniques
Compositional analysis and predicted structural analyses are informative, but in many cases actually detailed structures are required, which is in most cases beyond the capability of the Bruker UltraFlex II MALDI instrument. Thus, more detailed structural analyses may be required to support your project. We have access to other instruments through the Emory Integrated Proteomics Core that we anticipate will be available in the near future.
However, since Emory and UGA have agreed on reciprocal use of core facilities, the ECGC will be able to work with Emory investigators to access resources at the University of Georgia Complex Carbohydrate Research Center (CCRC) in Athens to support these more detailed analyses. Cost for these services will be based on the CCRC cost structure and determined based on nature of the request. A description of these services can be accessed at http://ccrc.uga.edu/services/ and these services include:
- Routine analyses of glycoconjugates
- Compositional analysis
- Glycosidic Linkage Analysis
- Molecular weight determination
- Proton-NMR of glycans
- N and O-Linked glycan profiling
- Glycolipid Analysis
- Separation by various chromatographic methods
- Fatty acid analysis
- Glycan composition, linkage analysis and sequencing
- Glycosaminoglycan (GAG) Analysis
- Digestion to disaccharides by enzymes
- Identification and characterization of released disaccharides
- Structural characterization of GAG by 1- and 2-D NMR
- Sequencing and compositional analysis of GAG
- 1-D 1H NMR and 13C NMR Spectroscopy
- 2-D NMR experiments (COSY, TOCST, HSQC
- Instruments Available:
- 300 MHz (2 channel, gradients)
- 500 MHz (89mm wide-bore magnet for solids and liquids)
- 600 MHz (3 channel, gradients)
- 800 MHz (3 channel, gradients)
- MS, LC/MS
- Matrix-Assisted Laser Desorption Mass Spectrometry (MALDI-MS)
- Electronspray Ionization Ion Trap Mass Spectrometry (ESI-MS/MS)
- High pH anion exchange chromatography (HPAEC)
- Gas Chromatography (GC) and Gas Chromatography-Mass Spectroscopy (GC-MS)
- Transcript analysis of glycan related genes
- >700 genes
- Chemical Synthesis of Glycans
- GAG oligosaccharides