The Synthesis of Defined Heparan Sulfate Fragments in the Exploration of Gag-Degrading Enzyme Specificity

Session: 
PS1 Poster session 1 Odd numbers
Code: 
P35
Location (hall): 
Foyer
Start/end time: 
Monday, July 1, 2019 - 15:45 to 17:15
Chih-Wei
Chang

Chih-Wei Chang1, Lisa Bohlmann1, Yu Xing1, Ifor Beacham1, Helen Blanchard1, Mark von Itzstein1

1Institute For Glycomics, Griffith University, Southport, Gold Coast, Australia

Glycosaminoglycans (GAGs) found either on cell membranes or in the extracellular matrix are a class of linear polysaccharides receptors that engage with a wide variety of proteins, resulting in various biological impacts. Investigation of specific GAG binding sequences within homogeneous GAG fragments and proteins is generally envisioned as an ideal approach to interrogate these biological recognition events. 

Here we describe a modular synthetic approach in the preparation of a well-defined heparan sulfate fragment library ranging from di- to octasaccharides which have been exploited to probe the substrate specificity of GAG-degradation enzymes including heparinases and heparanase. 

Bacterial heparinases have a long history of use in the cleavage of heparan sulfate (HS) and heparin for the production of low-molecular-weight heparin fragments (LMWHs). However, very little information is known about the substrate specificity of different types of heparinases. Here we employ various well-defined HS oligosaccharides to investigate the cleavage process catalysed by these two heparinases II from P. heparinus and B. eggerthii using 1H NMR spectroscopy. A broader substrate susceptibility to degradation by Heparinase II from P. heparinus was found, which provides us new insight regarding the substrate specificity of these different heparinases II [1]. 

In addition, the crystal structure of a heparanase (BpHep) from the invasive pathogenic bacterium Burkholderia pseudomallei (Bp) was recently disclosed by our group [2]. We also found that BpHep has specificity to these well-defined HS fragments. In summary, we have successfully prepared and used a well-characterized HS fragment library to investigate the differential degradation specificity of heparin and HS lyases and an endo-glycohydrolase. 

References: 
  1. Bohlmann, L.; Chang, C.-W.; Beacham, I.; von Itzstein, M., ChemBioChem 2015, 16, 1205–1211;
  2. Bohlmann, L.; Tredwell, G. D.; Yu, X.; Chang, C.-W.; Haselhorst, T.; Winger, M.; Dyason, J. C.; Thomson, R. J.; Tiralongo, J.; Beacham, I. R.; Blanchard, H.; von Itzstein, M., Nat Chem Biol 2015, 11, 955–957

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