BioFiles Volume 5, Number 1 — Glycobiology

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Select-HA Products Online

Hyaluronan (HA; hyaluronic acid) is a member of the glycosaminoglycan class of natural polysaccharides. Hyaluronan is a linear, unbranched polymer composed of alternating residues of β-D-(1→3) glucuronic acid (GlcA) and β-D-(1→4)-N-acetylglucosamine (GlcNAc) (see Figure 1). Unlike the other glycosaminoglycans, hyaluronan does not attach to proteins to form proteoglycans and it is not sulfated. Historically hyaluronan has been isolated from animal sources or extracted from bacteria, including strains of Staphylococcus.

In animals and bacteria, hyaluronan has a molecular mass from 104 to 107 Dalton, with multiple polymer components of varying chain length. Hyaluronan is a major constituent of the extracellular matrix but in addition HA is associated with multiple biological roles including modulation of cellular adhesion, signaling, wound healing, cellular regeneration, inflammation, and cancer.1-3

Other glycosaminoglycans (heparan/heparin and chondroitin) are modified through epimerization and sulfation, which results in biologically active variants. Hyaluronan is a unique glycosaminoglycan in that it is neither epimerized nor sulfated; instead, the variations in its biological function appear to be dependant on polymer size.1 Native hyaluronans are polymeric mixtures that may contain additional contaminants, so hyaluronan isolated from animal sources may introduce unwanted experimental variables.


Click on image for larger view.

Figure 1. Hyaluronic acid is composed of alternating residues of β-D-(1→3) glucuronic acid and β-D-(1→4)-N-acetylglucosamine.

Select-HA is a monodisperse hyaluronic acid prepared through enzymatic synthesis where a very high level of size control is possible. Each Select-HA is a narrow-size distribution HA with a specific average molecular weight within a defined range. Polydispersity of Select-HA is as low as 1.02 and averages 1.1, where an ideal polymer (all molecules being a uniform size) would have a polydispersity value of 1.

Select-HA is available as polymers of specific size. Select-HA HiLadder and Select-HA LoLadder are mixtures of five Select-HA hyaluronans of different molecular size. These ladders are designed for use as markers for agarose electrophoresis of polysaccharides.

Oligo-HA and nanoHA™ are hyaluronan oligosaccharides designed for research use. The Oligo-HA products are small-molecular weight hyaluronic acid oligomers prepared with streptococcal or recombinant bacterial HA via testicular HAase digestion and purified by gel filtration. The hyaluronan disaccharide subunit is glucuronic acid-β-D-(1→3)-N-acetyl-D-glucosamine-β-D-(1→4) (GlcAβ3GlcNAcβ4), and each Oligo-HA is an defined oligomer of the subunit.

The nanoHA products are small-molecular weight hyaluronic acid oligomers prepared by chemoenzymatic synthesis using immobilized enzymes.6 The name of each nanoHA indicates the number of monosaccharide units in the oligomer. The reducing end contains N-acetyl-D-glucosamine.


  1. Stern, R., et al., Hyaluronan fragments: an information-rich system. Eur. J. Cell Biol., 85, 699-715 (2006).
  2. Itano, N., Simple primary structure, complex turnover regulation and multiple roles of hyaluronan. J. Biochem., 144, 131-7 (2008).
  3. Toole, B.P. and Slomiany, M.G., Hyaluronan: a constitutive regulator of chemoresistance and malignancy in cancer cells. Semin. Cancer Biol., 18, 244- 50 (2008).
  4. Widner, B., et al., Hyaluronic acid production in Bacillus subtilis. Appl. Environ. Microbiol., 71, 3747-52 (2005).
  5. Jing, W. and DeAngelis, P.L., Synchronized chemoenzymatic synthesis of monodisperse hyaluronan polymers. J. Biol. Chem., 279, 42345-9 (2003).
  6. DeAngelis, P.L. et al., Rapid chemoenzymatic synthesis of monodisperse hyaluronan oligosaccharides with immobilized enzyme reactors. J. Biol. Chem., 278, 35199-203 (2003).


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