4‐O‐Substituted Glucuronic Cyclophellitols are Selective Mechanism‐Based Heparanase Inhibitors

Abstract

Supporting information for this article is given via a link at the end of the document.

Molecular Basis for Inhibition of Heparanases and β-Glucuronidases by Siastatin B

“…We next examined whether the synthetic 1- N -iminosugars could inhibit HPSE and human β-glucuronidase. To assess the potency of these inhibitors, we used a competitive activity-based protein profiling (cABPP) assay, that measures the ability of the inhibitor to reduce fluorescent labeling of an enzyme by a fluorescent pan-β-glucuronidase activity-based probe (ABP). , Using this cABPP assay, we can simultaneously monitor the inhibition of HPSE and GUSB that are both present in platelet lysates. , As for the bacterial β-glucuronidases, human GUSB was also effectively inhibited by all the synthesized inhibitors ( 8 – 11 ), with low or submicromolar IC 50 ’s observed, see Table and Figures , S7–S9. As observed with the bacterial β-glucuronidases, the gluco -configured inhibitors 9 and 11 were more potent inhibitors of human GUSB than their 4-axial galacto -analogues.…”

“…To assess the potency of these inhibitors, we used a competitive activitybased protein profiling (cABPP) assay, that measures the ability of the inhibitor to reduce fluorescent labeling of an enzyme by a fluorescent pan-β-glucuronidase activity-based probe (ABP). 16,34 Using this cABPP assay, we can simultaneously monitor the inhibition of HPSE and GUSB that are both present in platelet lysates. 6,29 As for the bacterial βglucuronidases, human GUSB was also effectively inhibited by all the synthesized inhibitors (8−11), with low or submicromolar IC 50 's observed, see Table 3…”

“…32 However, this solventmediated rearrangement has not been demonstrated for siastatin B, which has always been regarded as stable in aqueous solution. 33 Our interest in heparanase inhibitors 29,34 has led us to reexamine the inhibition of heparanases and β-glucuronidases by siastatin B. Human heparanase (HPSE) is an endo-βglucuronidase that catalyzes the cleavage of heparan sulfate (HS).…”

“…Our interest in heparanase inhibitors , has led us to re-examine the inhibition of heparanases and β-glucuronidases by siastatin B. Human heparanase (HPSE) is an endo -β-glucuronidase that catalyzes the cleavage of heparan sulfate (HS).…”