PDBsum entry 6asp

Chaperone/inhibitor

PDB id: 6asp

Contents

Protein chains

215 a.a.

Ligands

P33 ×17

GOL ×2

V2C ×2

Waters ×37

PDB id:

6asp

Name:

Chaperone/inhibitor

Title:

Structure of grp94 with methyl 3-chloro-2-(2-(1-(2-ethoxybenzyl)-1 h- imidazol-2-yl)ethyl)-4,6-dihydroxybenzoate, a grp94-selective inhibitor and promising therapeutic lead for treating myocilin- associated glaucoma

Structure:

Endoplasmin. Chain: a, b. Fragment: unp residues 69-286, gggg linker, 328-337. Synonym: 94 kda glucose-regulated protein, grp-94, heat shock protein 90 kda beta member 1. Engineered: yes

Source:

Canis lupus familiaris. Dog. Organism_taxid: 9615. Gene: hsp90b1, grp94, tra1. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

2.70Å R-factor: 0.184 R-free: 0.238

Authors:

D.J.E.Huard,R.L.Lieberman

Key ref:

D.J.E.Huard et al. (2018). Trifunctional High-Throughput Screen Identifies Promising Scaffold To Inhibit Grp94 and Treat Myocilin-Associated Glaucoma. ACS Chem Biol, 13, 933-941. PubMed id: 29402077 DOI: 10.1021/acschembio.7b01083

Date:

25-Aug-17 Release date: 18-Apr-18

Protein chains

P41148  (ENPL_CANLF) -  Endoplasmin from Canis lupus familiaris

Seq: 804 a.a.

Struc: 215 a.a.*

* PDB and UniProt seqs differ at 8 residue positions (black crosses)

DOI no: 10.1021/acschembio.7b01083

ACS Chem Biol 13:933-941 (2018)

PubMed id: 29402077

Trifunctional High-Throughput Screen Identifies Promising Scaffold To Inhibit Grp94 and Treat Myocilin-Associated Glaucoma.

D.J.E.Huard, V.M.Crowley, Y.Du, R.A.Cordova, Z.Sun, M.O.Tomlin, C.A.Dickey, J.Koren, L.Blair, H.Fu, B.S.J.Blagg, R.L.Lieberman.

ABSTRACT

Gain-of-function mutations within the olfactomedin (OLF) domain of myocilin result in its toxic intracellular accumulation and hasten the onset of open-angle glaucoma. The absence of myocilin does not cause disease; therefore, strategies aimed at eliminating myocilin could lead to a successful glaucoma treatment. The endoplasmic reticulum Hsp90 paralog Grp94 accelerates OLF aggregation. Knockdown or pharmacological inhibition of Grp94 in cells facilitates clearance of mutant myocilin via a non-proteasomal pathway. Here, we expanded our support for targeting Grp94 over cytosolic paralogs Hsp90α and Hsp90β. We then developed a high-throughput screening assay to identify new chemical matter capable of disrupting the Grp94/OLF interaction. When applied to a blind, focused library of 17 Hsp90 inhibitors, our miniaturized single-read in vitro thioflavin T -based kinetics aggregation assay exclusively identified compounds that target the chaperone N-terminal nucleotide binding site. In follow up studies, one compound (2) decreased the extent of co-aggregation of Grp94 with OLF in a dose-dependent manner in vitro, and enabled clearance of the aggregation-prone full-length myocilin variant I477N in cells without inducing the heat shock response or causing cytotoxicity. Comparison of the co-crystal structure of compound 2 and another non-selective hit in complex with the N-terminal domain of Grp94 reveals a docking mode tailored to Grp94 and explains its selectivity. A new lead compound has been identified, supporting a targeted chemical biology assay approach to develop a protein degradation-based therapy for myocilin-associated glaucoma by selectively inhibiting Grp94.