In vitro pharmacological profiling of selected small molecules compound using recombinant human iduronate-2-sulphatase

Abstract

Background: Mucopolysaccharidoses type II (MPS II) is an X-linked lysosomal storage disease (LSD). It is due to mutation in IDS gene encoding iduronate-2-sulphatase (IDS) involved in the catabolism of dermatan sulphate and heparan sulphate. Currently, the treatments for MPS II patients are enzyme replacement therapy (ERT) and bone marrow transplantation (BMT). However, ERT is not effectively reducing the central nervous system manifestation and finding the suitable donor maybe quite challenging in BMT. Over the past decades, pharmacological chaperone has been an alternative approach for management of MPS II patient. Here, we described the in vitro profiling of small molecules in group of chondroitin/dermatan (CD) sulphate disaccharide, heparin oligosaccharides, unsaturated heparin disaccharides and 6-O-desulphated heparin oligosaccharide, using recombinant human iduronate-2-sulphatase (rhIDS). Twenty-one small molecule compounds with several concentrations were each screened by inhibition and thermal stability assays.
 Results: Our study revealed that condroitin dermatan trisulphate (CD3S), heparin tetrasaccharide (H4Sac), heparin octasaccharide (H8Sac) and heparin octadecasaccharide (H18Sac) showed high inhibition constant, Ki and low inhibition concentration, IC50 in comparison to others. In the thermal stability study, only rhIDS incubated with CD3S was found to preserve enzyme activity (20%) after incubated at 67oC.
 Conclusion: Overall, our experiments discovered that CD3S was able to bind, inhibit and chaperone rhIDS. These features suggest a potential pharmacological chaperone for MPS II.