Chemoenzymatic synthesis with distinct Pasteurella heparosan synthases: monodisperse polymers and unnatural structures

J Biol Chem. 2007 Sep 28;282(39):28321-28327. doi: 10.1074/jbc.M701599200. Epub 2007 Jul 11.


Heparosan (-GlcUA-beta1,4-GlcNAc-alpha1,4-)(n) is a member of the glycosaminoglycan polysaccharide family found in the capsule of certain pathogenic bacteria as well as the precursor for the vertebrate polymers, heparin and heparan sulfate. The two heparosan synthases from the Gram-negative bacteria Pasteurella multocida, PmHS1 and PmHS2, were efficiently expressed and purified using maltose-binding protein fusion constructs. These relatively homologous synthases displayed distinct catalytic characteristics. PmHS1, but not PmHS2, was able to produce large molecular mass (100-800 kDa) monodisperse polymers in synchronized, stoichiometrically controlled reactions in vitro. PmHS2, but not PmHS1, was able to utilize many unnatural UDP-sugar analogs (including substrates with acetamido-containing uronic acids or longer acyl chain hexosamine derivatives) in vitro. Overall these findings reveal potential differences in the active sites of these two Pasteurella enzymes. In the future, these catalysts should allow the creation of a variety of heparosan and heparinoids with utility for medical applications.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Glycosaminoglycans / chemical synthesis*
  • Glycosaminoglycans / chemistry
  • Glycosyltransferases / chemistry*
  • Glycosyltransferases / genetics
  • Maltose-Binding Proteins
  • Pasteurella multocida / enzymology*
  • Pasteurella multocida / genetics
  • Polymers / chemical synthesis*
  • Polymers / chemistry
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / genetics
  • Uridine Diphosphate Sugars / chemistry
  • Uronic Acids / chemistry


  • Bacterial Proteins
  • Carrier Proteins
  • Glycosaminoglycans
  • Maltose-Binding Proteins
  • Polymers
  • Recombinant Fusion Proteins
  • Uridine Diphosphate Sugars
  • Uronic Acids
  • Glycosyltransferases
  • heparosan synthase