Our Products
A modern Glycoproduct portfolio for the Omics Era
The omics fields such as glycomics and glycoproteomics are generating tremendous amounts of data in addition to the well-established genomics, transcriptomics, proteomics, lipidomics and metabolomics fields. Integration of the various ‘omics’ fields is moving science toward an holistic understanding of cellular biology in health and disease. Carbohydrates are at the interface of these fields.
Sussex Research Laboratories Inc. has developed a modern glyco product portfolio designed to help researchers explore glycobiology for glycotherapeutic applications. We translate complex carbohydrate chemistries into unique, leading-edge products designed to help researchers explore and exploit glycobiology with a view to advancing the field and creating new biomedical applications that advance human health.
Biotinylated Ligands
Biotinyl glycans are emerging as a valuable class of carbohydrate or glycoconjugate probes that allow exploitation of the strong affinity of avidin and streptavidin for biotin, a feature vastly utilized across molecular biology for decades. Techniques for the study of protein–carbohydrate interactions are of great interest in glycobiology and to this day, Sussex Research Laboratories Inc. has been developing biotinylated saccharides to advance research in the field.
Carbohydrate-protein interactions play crucial roles in a myriad of biological processes such as cell adhesion, inflammation and immune response. Such interactions, where glycans act as recognition elements or ligands, form the basis of specific recognition of carbohydrates by lectins (carbohydrate recognizing proteins) and are at the heart of glycobiology.
Sussex Research Laboratories Inc. has developed synthetic biotinyl glycan, glycoamino acid and glycopeptide reagents as tools to facilitate the functional analysis of lectins. Biotinylated glycan reagents may be used to:
- Determine binding specificities of lectins via glycan arrays
- Determine binding specificities of lectins via Surface Plasmon Resonance (SPR)
- Visualize lectin-expressing cells in vitro via fluorescent streptavidin or avidin beads coated with specific biotinylated glycans
- Visualize lectin-expressing cells in tissues.
- Purify lectins via affinity chromatography
- Screening
Sussex Research Laboratories Inc. retains the structure and biological integrity of the glycan ligands. O- and N-linked biotinylated sugars are stable and very reliable for use in the study of protein-carbohydrate interactions. Most biotinylated sugars from Sussex Research Laboratories Inc. incorporate short, monodisperse (discrete), amphiphilic polyethylene glycol (PEG) spacers such as triethylene glycol (PEG3), a 9-atom spacer, which may confer certain advantages over traditional hydrophobic alkyl (CH2)n linkers. PEG is a stable, amphiphilic spacer molecule that offsets the very hydrophobic nature of biotin. PEG enables solubility across a wide range of solvent systems including aqueous media.
Carbohydrate Ligands
Exploiting lectin/carbohydrate-mediated drug delivery through use of glycobiology may offer a means of addressing specific challenges of delivering and targeting difficult therapeutic molecules. The idea of using lectin-carbohydrate interactions to mediate cell targeting and cellular uptake of molecules in general has been under intense investigation in recent years. There is potential for carbohydrate ligands to specifically solubilize, introduce and activate therapeutic macromolecules into diseased cells in a manner that allows for specific and controlled modulation of protein production. Cell-specific delivery of therapeutic agents via carbohydrate ligand targeting has gained interest due to its potential for increased efficacy and reduced side effects.
Sussex Research Laboratories Inc. is the leading commercial source of synthetic, well-defined carbohydrate ligands. These are multi-purpose, functionalized products that enable researchers to modify virtually any molecule large or small with carbohydrates via simple discrete, monodisperse polyethylene glycol (PEG) or alkyl linker/spacer systems. In contrast to traditional alkyl linker/spacers, PEG linker/spacers are water soluble and amphiphilic which reduces linker hydrophobic interactions with macromolecules and surfaces.
Various functionalized carbohydrate ligands include:
- DBCO (dibenzocyclooctyne) – react with azides via copperless click chemistry
- Alkynes – react with azides via copper-catalyzed click chemistry
- Azides – react with triple bonds via click chemistry
- Maleimides – react with thiols
- Amines – react with carboxylic acids
- Carboxylic acids – amine reactive
- NHS esters (including sulfo-NHS esters) – amine reactive
- Pentafluorophenolic esters – amine reactive
- Biotin – for detection of tris-GalNAc ligands via streptavidin
- Fluorescein – for detection of tris-GalNAc ligands
- Lipids – preparation of targeted nanoparticles
- Alkyl and discrete, monodisperse polyethylene glycols (PEGS)
- Polydisperse polyethylene glycols (PEGS)
If you’re unable to find what you’re looking for, please request for a custom synthesis.
GalNAc Ligands
Exploiting GalNAc in receptor-mediated drug delivery through use of glycobiology offers a means of addressing the specific challenge of delivering and targeting therapeutic molecules such as proteins, antibodies and oligonucleotides. The idea that carbohydrates, including GalNAc, mediate receptor binding, cell targeting and cellular uptake of molecules has been been known for decades. The Ashwell–Morell receptors found in liver hepatocytes, originally and more commonly referred to as the asialoglycoprotein receptor (ASGPR), was the first lectin to be detected in mammals and the first cellular receptor to be identified and isolated. It is one of the multiple lectins of the C-type lectin family involved in recognition, binding, and clearance of asialo glycoproteins. GalNAc has been adopted and successfully applied as a targeting ligand in antisense oligonucleotides and siRNA guiding therapeutic payloads into liver cells. Cell-specific delivery of therapeutic agents via ASGPR using GalNAc ligands offers incredible potential.
Sussex Research Laboratories Inc. has developed an extensive selection of functionalized GalNAc ligands with various alkyl and/or polyethylene glycol (PEG) linker/spacer systems. These enable facile introduction of GalNAc-based recognition elements onto a variety of molecules including but not limited to small molecules, surfaces, nanoparticles, peptides, proteins, antibodies, lipids and oligonucleotides.
Various functionalized GalNAc ligands include:
- DBCO (dibenzocyclooctyne) – react with azides via copperless click chemistry
- Alkynes – react with azides via copper-catalyzed click chemistry
- Azides – react with triple bonds via click chemistry
- Maleimides – react with thiols
- Amines – react with carboxylic acids
- Carboxylic acids – amine reactive
- NHS esters (including sulfo-NHS esters) – amine reactive
- Pentafluorophenolic esters – amine reactive
- Controlled Pore Glass (CPG)
- Biotin – for detection of tris-GalNAc ligands via streptavidin
- Fluorescein – for detection of tris-GalNAc ligands
- Lipids – preparation of targeted nanoparticles
- Alkyl and discrete, monodisperse polyethylene glycols (PEGS)
- Polydisperse polyethylene glycols (PEGS)
If you’re unable to find what you’re looking for, please request for a custom synthesis.
Glycoamino Acids
Sussex Research Laboratories Inc. has provided researchers with the most extensive selection of commercially available, high purity glycosylated amino acids (glycoamino acids) for over 20 years.
In nature, protein glycosylation, forming glycoproteins or glycopeptides, is a fundamental posttranslational modification process that controls protein shape, half-life and essential biological pathways ranging from protein trafficking to cell adhesion. Glycoamino acids are the basic sites of protein glycosylation, most commonly occurring at serine and threonine in the case of O-linked proteins, and at asparagine (Asn) in the case of N-linked glycoproteins. To a lesser extent, glycosylation may also occur at other amino acids but this is far less common.
Fmoc Glycoamino Acids: Sussex Research Laboratories Inc. provides an advanced glycopeptide custom synthesis service, but for researchers who have the knowledge and capability to produce their own glycopeptides, our high purity Fmoc glycoamino acid building blocks enable facile assembly of glycocpeptides as well as introduction of carbohydrate-based recognition elements into virtually any synthetic molecule including small molecules and biomolecules such as oligonucleotides and proteins.
Fmoc glycoamino acid building blocks are anomerically pure, equipped with protected sugars and contain free acids that are ready for solution phase or automated solid phase peptide synthesis (SPPS). All Fmoc glycoamino acids are available in a variety of quantities. We also provide bulk quantities for use in large scale GMP manufacturing of glycopeptides for clinical use. Modified or customized glycoamino acids, including partially protected or fully deprotected glycoamino acids may be manufactured upon request.
Non-blocked, natural glycoamino acids are also available for analytical or biological applications.
If you’re unable to find what you’re looking for, please request for a custom synthesis.
Glycopeptides
Sussex Research Laboratories Inc. is the global leader in the field of glycopeptide synthesis and is the leading commercial source of synthetic, well-defined and characterized glycosylated peptides. We have been expanding our synthetic capabilities in the production of N- and O-linked glycopeptides for close to 20 years. We are also well-versed in the development of lipo, glyco-lipo, macrocyclic-, glycated (fructosylated), fluorescent/biotin-tagged and stable isotope-labelled glycopeptides and peptides.
Glycopeptides for Research & Development
Glycopeptides offer a unique frontier for research & development. Many critical roles of glycan elements on cell surface proteins and those bound to circulatory proteins are being recognized. Carbohydrates on proteins mediate a host of biological events including cell adhesion, immune system function, fertilization, cellular targeting as well as protein transport, stabilization, and half-life. Thus, the use of synthetic glycoproteins or their short glycopeptide fragments as experimental probes for basic research and biomedical applications is growing rapidly.
Glycopeptides for Drug Discovery & Development
Glycosylation of peptides is known to increase stability, solubility, in vivo half lives and ultimately, the efficacy of peptides in many cases. Glycosylation can impart very dramatic and beneficial biological effects in peptides and proteins. Short, stable, well characterized glycopeptide sequences taken from larger proteins can be highly potent ligands.
Glycopeptides from Our Library
As the leading resource for glycopeptide synthesis, Sussex Research Laboratories Inc. offers a large number of glycopeptides from our inventory including but certainly not limited to:
- Mucins such as MUC1 and cancer-related glycopeptides
- Erythropoietin analogues
- RNA polymerase II C-Terminal Domain
- IgA Hinge domain glycopeptides
- PSGL-1 mimetics
- Frizzled 8 analogues (FRZD8 or Antiproliferative factor)
- O-GlcNAc nucleocytoplasmic protein fragments
- Glycated hemoglobin fragments
Synthetic O-linked Glycopeptides
Oxygen-linked (O-linked) glycopeptides and proteins are highly prevalent on cell surfaces and extracellular proteins. The most abundant type of O-glycosylation in proteins is the N-acetylgalactosamine or alpha-GalNAc attachment to Ser or Thr in the protein chain. Most eukaryotic nuclear and cytoplasmic proteins are modified by N-acetylglucosamine (beta-O-GlcNAc) linked to Ser or Thr. Less prevalent types of O-glycosylation involve O-fucose (Fuc), O-mannose (Man) and O-glucose (Glc). However these are functionally of high relevance for early stages of development and for vital physiological functions of proteins. Glycosaminoglycans (GAG) are linked to proteoglycans via xylose (Xyl) linked to Ser.
Synthetic N-Linked Glycopeptides
Nitrogen-linked (N-linked) glycosylation is a post translational process that occurs in eukaryotes and widely in archaea but is rare in bacteria. It’s now understood that N-glycosylation plays a role in the folding of many eukaryotic proteins. Thus, approximately 70% of human therapeutic proteins contain N-linked glycans which contribute to increased in vivo half-life and bioavailability and hence higher therapeutic efficacy.
Glycated Peptides
Peptide glycation results from non-enzymatic covalent attachment of sugars (particularly glucose) to proteins. Glycation often occurs at the N-terminal groups of proteins or at the side chains of lysines, arginines, cysteines, and histidines. Glycations occur mainly in the bloodstream concentrations of absorbed simple sugars such as glucose are high. Glycation end products are therefore implicated in many micro and macrovascular complications in diabetes, other diseases and in aging.
Custom Glycopeptide Synthesis
The number and variation in applications of glycopeptides in modern research is impressive. Sussex Research Laboratories Inc. is highly active in the custom synthesis of glycopeptides for specific research, drug, and vaccine development projects. You pick the glycoform, the amino acid or linker system, the sequence, and the probe or label if necessary, and we’ll make it happen.
Mono, Oligo & Polysaccharides
Sussex Research Laboratories Inc. prides itself on its ability to synthesize, purify and fully characterize complex carbohydrate systems such as oligosaccharides. From cancer antigens to glycosaminoglycan (GAG) oligosaccharides, we are experienced in virtually all aspects of oligosaccharide synthesis. The company has an excellent infrastructure including in-house high field NMR and mass spectrometry facilities for structural validation. We use chemical, enzymatic and chemoenzymatic approaches to synthesize our oligosaccharides that are purified and subject to full structural characterization via Proton, Carbon and 2-dimensional NMR techniques along with mass spectrometry.
Carbohydrate
A generic term used interchangeably with terms such as saccharide, sugar, or glycan and includes other terms such monosaccharides, oligosaccharides and polysaccharides.
Monosaccharides
The basic carbohydrate building blocks of larger sugars (oligosaccharides, glycans, polysaccharides). Common monosaccharides found in eukaryotes are: N-Acetylgalactosamine (GalNAc), N-acetylglucosamine (GlcNAc), fucose (Fuc), galactose (Gal), glucose (Glc), mannose (Man), N-acetylneuraminic acid (sialic acid, NeuAc), xylose (Xyl), glucuronic acid (GlcA), and iduronic acid (IdUA).
Oligosaccharides are short chains or oligomers of monosaccharides (typically 2-10) connected via glycosidic linkages. Oligosaccharides may be referred to as glycans when conjugated to cell surface lipids or proteins. Oligosaccharides coat the majority of cell surface and circulatory proteins via conjugation to serine, threonine or asparagine. When conjugated to cell surface lipids and proteins, oligosaccharides are involved in a host of processes including but not limited to cellular recognition, cell adhesion, fertilization and immune function – little wonder that oligosaccharides are now being applied to diagnostic, therapeutic and vaccine development.
Glycans refer to the carbohydrate (oligosaccharide or polysaccharide) portion of glycoconjugate, such as a glycoprotein, glycolipid, or a proteoglycan.
Glycosaminoglycans (GAGs) are a family of charged, highly sulfated oligosaccharides predominantly found as long unbranched polysaccharides containing repeating disaccharide units consisting either of N-acetylgalactosamine (GalNAc) or N-acetylglucosamine (GlcNAc) and uronic acids such as glucuronic acid (GlcA) or iduronic acid (IdoA).
Proteoglycans When GAGs are conjugated to proteins, the overall structure is referred to as a proteoglycan. These highly negatively charged glycans have been implicated in numerous biological processes including brain development, anticoagulation, cancer, inflammation, and spinal cord injury. Heparin, a pharmaceutical injectable, is widely used as an anticoagulant and is derived from mucosal tissues of porcine and bovine.
Polysaccharides (PS) are very long polymeric chains of monosaccharides connected via glycosidic linkages. While oligosaccharides generally contain 2-10 monosaccharide units, polysaccharides contain >10 and often >>1,000. Polysaccharides are found in plants and other lifeforms including bacteria and humans and may be neutral or charged. Some Glycosaminoglycans may be considered polysaccharides.
Lipopolysaccharides (LPS) consist of a polysaccharide conjugated to a lipid and are major components of the outer membrane of Gram-negative bacteria. LPS act as endotoxins eliciting strong immune responses in humans and are important in the development of vaccines. Our inventory of isolated LPS (and also capsular polysaccharides (CPS)) are derived from bacterial pathogens, including strains of Bordetella, E. coli, Francisella, Pseudomonas, Salmonella and Streptococcus to name just a few. LPS have been characterized via a variety of techniques including high field nmr and mass spectrometry. Associated antibodies may also be available in some cases.
{-4)-α-D-GalpNAcAN-(1-4)-α-D-GalpNAcAN-(1-3)-β-D-QuipNAc-(1-2)-β-D-QuipNAcFm-(1-}
Repeat unit of Francisella tularensis
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