NIH Chemical Genomics Center [NCGC]
NIH Molecular Libraries Probe Production Centers Network [MLPCN]

MLPCN Grant: MH086442-01
Assay Submitter (PI): Wei Zheng

Glucocerebrosidase (GC) catalyzes the hydrolysis of beta-glucocerebroside to glucose and ceramide in lysosomes. Mutations in the glucocerebrosidase gene result in Gaucher disease, an autosomal recessive lysosomal storage disorder. Many of the mutations encountered in patients with Gaucher disease are missense alterations that may cause misfolding, decreased stability and/or mistrafficking of this lysosomal protein. Some GC inhibitors have been shown to act as chemical chaperones, stabilizing the conformation of mutant proteins and thus restoring their function. These inhibitors include iminosugar analogs and three non-iminosugar inhibitors identified from a previous HTS of 62,000 compounds with the wild type recombinant enzyme. However, the enhancement of enzyme activity by the chaperone action of an enzyme inhibitor must be balanced against the direct inhibition of the enzyme. An enzyme activator could also function as a chaperone by binding to the enzyme and helping to correct its misfolding and mistrafficking. While activators for GC have not yet been identified, they may have better therapeutic potential than inhibitors. Therefore the discovery and development of chemical activators may provide a new strategy for the chaperone therapy.

We have optimized a new assay using N370S mutant GC derived from the spleen of a Gaucher patient. The new assay differs significantly from the previous screen because the N370S mutant enzyme is used instead of wildtype GC and an enzyme preparation derived from patient tissue instead of the purified recombinant GC that should have the physiologically relevant subunit/subunits and cofactors. In addition, the MLPCN compound library has expanded, which increases the chance of finding new and better probes.

See non-summary AIDS for detailed assay protocols.

This summary is written for the purposes of summarizing the probe activities from the project. MLSCN probes are given a score of 100. Molecules in the prior art are given a score of 80. Other, less active molecules in the same chemical series as the probe molecules are given a score of 50. Inactive analogues from these series are given a score of 0. ML155 (SID 85267237) and ML156 (SID 89449177) have been declared as probes on this project.

Grant Number: MH086442-01