9KMB | pdb_00009kmb

Crystal structure of human glutaminyl cyclase in complex with N-(2-(1H-imidazol-5-yl)ethyl)-4-methoxybenzenesulfonamide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.28 Å
  • R-Value Free: 
    0.266 (Depositor), 0.272 (DCC) 
  • R-Value Work: 
    0.216 (Depositor), 0.220 (DCC) 
  • R-Value Observed: 
    0.218 (Depositor) 

Starting Model: experimental
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Literature

Deciphering Glutaminyl Cyclase Catalytic Pathways Enables Recognition of Anchor Pharmacophores for Inhibitor Discovery.

Wu, J.W.Ning, X.L.Tang, B.D.Chen, Y.T.Yang, Z.B.Meng, F.B.Zhou, C.Yu, J.L.Li, R.Li, Z.Li, G.B.

(2025) J Chem Inf Model 65: 5006-5018

  • DOI: https://doi.org/10.1021/acs.jcim.5c00498
  • Primary Citation of Related Structures:  
    9KMB

  • PubMed Abstract: 

    Glutaminyl cyclases are responsible for N-terminal pyroglutamate modifications of various protein/peptide substrates, influencing their metabolic stability or biological functions. However, the precise chemical pathways by which glutaminyl cyclases catalyze the conversion of N-terminal glutamine/glutamate to pyroglutamate are not yet fully understood. We initially identified the catalytically essential components by cross-species structural analysis, followed by ab initio quantum mechanics/molecular mechanics (QM/MM) calculations of human secretory glutaminyl cyclase (sQC) with two tripeptide substrates, QFA and EFA . The results revealed that sQC processes similar reaction pathways for QFA and EFA , but with distinctly different reaction energy barriers. In both reaction pathways, the catalytic triad E201 directly mediates multiple proton transfers, while D248 and D305 primarily maintain the orientation of the triad and stabilize substrate binding. Based on the anchor pharmacophores recognized by the analysis of sQC catalytic intermediates, we successfully identified the imidazole-sulfonamide inhibitors that mimic substrate binding, as validated by cocrystallographic analysis.


  • Organizational Affiliation
    • Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Department of Medicinal Chemistry, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.

Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Glutaminyl-peptide cyclotransferase
A, B, C
329Homo sapiensMutation(s): 0 
Gene Names: QPCT
EC: 2.3.2.5
UniProt & NIH Common Fund Data Resources
Find proteins for Q16769 (Homo sapiens)
Explore Q16769 
Go to UniProtKB:  Q16769
PHAROS:  Q16769
GTEx:  ENSG00000115828 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ16769
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.28 Å
  • R-Value Free:  0.266 (Depositor), 0.272 (DCC) 
  • R-Value Work:  0.216 (Depositor), 0.220 (DCC) 
  • R-Value Observed: 0.218 (Depositor) 
Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 106.575α = 90
b = 147.17β = 90
c = 160.33γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
autoPXdata processing
autoPXdata reduction
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Natural Science Foundation of China (NSFC)China--

Revision History  (Full details and data files)

  • Version 1.0: 2025-06-25
    Type: Initial release