Title : Activity-based probes for functional interrogation of retaining β-glucuronidases
Abstract :
- Humans express at least two distinct β -glucuronidase enzymes that are involved in disease: exo-acting β -glucuronidase ( GUSB ), whose deficiency gives rise to mucopolysaccharidosis type VII, and endo-acting heparanase ( HPSE ), whose overexpression is implicated in inflammation and cancers
- The medical importance of these enzymes necessitates reliable methods to assay their activities in tissues
- Herein, we present a set of β -glucuronidase-specific activity-based probes (ABPs) that allow rapid and quantitative visualization of GUSB and HPSE in biological samples, providing a powerful tool for dissecting their activities in normal and disease states
- Unexpectedly, we find that the supposedly inactive HPSE proenzyme pro HPSE is also labeled by our ABPs, leading to surprising insights regarding structural relationships between pro HPSE , mature HPSE , and their bacterial homologs
- Our results demonstrate the application of β -glucuronidase ABPs in tracking pathologically relevant enzymes and provide a case study of how ABP-driven approaches can lead to discovery of unanticipated structural and biochemical functionality