Biology subjects

Schapira, M.

Publications and source records attributed to Schapira, M..

2 recordsLinked to original sources

bioRxiv2018

Identification and Structure-Activity Relationship of HDAC6 Zinc-finger Ubiquitin Binding Domain Inhibitors

HDAC6 plays a central role in the recruitment of protein aggregates for lysosomal degradation, and is a promising target for combination therapy with proteasome inhibitors in multiple myeloma. Pharmacologically displacing ubiquitin from the zinc-finger ubiquitin-binding domain (ZnF-UBD) of HDAC6 is an underexplored alternative to catalytic inhibition. Here, we present the discovery of a HDAC6 ZnF-UBD-focused chemical series and its progression from virtual screening hits to low micromolar inhibitors. A carboxylate mimicking the C-terminal extremity of ubiquitin, and an extended aromatic system stacking with W1182 and R1155 are necessary for activity. One of the compounds induced a conformational remodeling of the binding site where the primary binding pocket opens-up onto a ligand-able secondary pocket that may be exploited to increase potency. The preliminary structure-activity relationship accompanied by nine crystal structures should enable further optimization into a chemical probe to investigate the merit of targeting the ZnF-UBD of HDAC6 in multiple myeloma and other diseases.

biophysics↗

bioRxiv2017

A Systematic Analysis Of Atomic Protein-Ligand Interactions In The PDB

As the protein databank (PDB) recently passed the cap of 123,456 structures, it stands more than ever as an important resource not only to analyze structural features of specific biological systems, but also to study the prevalence of structural patterns observed in a large body of unrelated structures, that may reflect rules governing protein folding or molecular recognition. Here, we compiled a list of 11,016 unique structures of small-molecule ligands bound to proteins - 6,444 of which have experimental binding affinity - representing 750,873 protein-ligand atomic interactions, and analyzed the frequency, geometry and impact of each interaction type. We find that hydrophobic interactions are generally enriched in high-efficiency ligands, but polar interactions are over-represented in fragment inhibitors. While most observations extracted from the PDB will be familiar to seasoned medicinal chemists, less expected findings, such as the high number of C-H ...O hydrogen bonds or the relatively frequent amide-{pi} stacking between the backbone amide of proteins and aromatic rings of ligands, uncover underused ligand design strategies.

biophysics↗