9QAT | pdb_00009qat

Human angiotensin-1 converting enzyme N-domain in complex with quinaprilat


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 
    0.210 (Depositor), 0.219 (DCC) 
  • R-Value Work: 
    0.166 (Depositor), 0.175 (DCC) 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


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Literature

Molecular basis of domain-specific angiotensin I-converting enzyme inhibition by the antihypertensive drugs enalaprilat, ramiprilat, trandolaprilat, quinaprilat and perindoprilat.

Gregory, K.S.Ramasamy, V.Sturrock, E.D.Acharya, K.R.

(2025) FEBS J 

  • DOI: https://doi.org/10.1111/febs.70232
  • Primary Citation of Related Structures:  
    9QAN, 9QAO, 9QAP, 9QAQ, 9QAR, 9QAS, 9QAT, 9QAU, 9QAV

  • PubMed Abstract: 

    Angiotensin I-converting enzyme (ACE) is a dipeptidyl carboxypeptidase with two homologous catalytic domains [N- and C-domains (nACE and cACE)] that can cleave a range of substrates. cACE primarily cleaves the inactive decapeptide angiotensin I into the potent vasopressor angiotensin II, whereas nACE preferentially cleaves the antifibrotic tetrapeptide N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP). Several ACE inhibitors, which bind to both cACE and nACE active sites, are used clinically for the treatment of hypertension; however, serious side effects are seen in ~ 20-25% of patients due to nonselective inhibition. To improve ACE inhibitor side effect profiles, the design and development of selective inhibitors of cACE or nACE is desirable for the treatment of hypertension or fibrosis. The detailed molecular basis through which the clinically available ACE inhibitors bind and inhibit cACE and nACE was unknown. Thus, in this study, we have characterised the structural and kinetic basis for the interaction between cACE and nACE with enalaprilat, ramiprilat, trandolaprilat, quinaprilat and perindoprilat. The inhibitors display nanomolar inhibition of both domains, with moderate-to-low cACE-selectivity. Trandolaprilat possesses the highest affinity for both nACE and cACE, whereas quinaprilat displayed the largest cACE-selectivity. None of the binding modes of the inhibitors extend beyond the S1-S2' subsites to make use of the unique nACE/cACE residues that have been shown to influence domain selectivity. These findings supplement our understanding of ACE inhibition by the clinically used ACE inhibitors, and this information should be useful in the future design of more domain-selective inhibitors for the treatment of hypertension and cardiovascular diseases.


  • Organizational Affiliation
    • Department of Life Sciences, University of Bath, UK.

Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Angiotensin-converting enzyme, soluble form
A, B
609Homo sapiensMutation(s): 7 
Gene Names: ACEDCPDCP1
EC: 3.4.15.1
UniProt & NIH Common Fund Data Resources
Find proteins for P12821 (Homo sapiens)
Explore P12821 
Go to UniProtKB:  P12821
PHAROS:  P12821
GTEx:  ENSG00000159640 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP12821
Glycosylation
Glycosylation Sites: 3Go to GlyGen: P12821-1
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

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Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranoseC [auth D]2N-Glycosylation
Entity ID: 3
MoleculeChains Length2D Diagram Glycosylation3D Interactions
beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranoseD [auth E]4N-Glycosylation
Entity ID: 4
MoleculeChains Length2D Diagram Glycosylation3D Interactions
alpha-L-fucopyranose-(1-6)-2-acetamido-2-deoxy-beta-D-glucopyranoseE [auth F],
G [auth H]
2N-Glycosylation
Entity ID: 5
MoleculeChains Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranoseF [auth G]3N-Glycosylation
Small Molecules
Ligands 12 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
A1I5A (Subject of Investigation/LOI)
Query on A1I5A

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EA [auth B],
M [auth A]
quinaprilat
C23 H26 N2 O5
FLSLEGPOVLMJMN-YSSFQJQWSA-N
P6G
Query on P6G

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R [auth A]HEXAETHYLENE GLYCOL
C12 H26 O7
IIRDTKBZINWQAW-UHFFFAOYSA-N
NAG
Query on NAG

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Z [auth B]2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
PG4
Query on PG4

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FA [auth B],
Y [auth B]
TETRAETHYLENE GLYCOL
C8 H18 O5
UWHCKJMYHZGTIT-UHFFFAOYSA-N
PGE
Query on PGE

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DA [auth B]TRIETHYLENE GLYCOL
C6 H14 O4
ZIBGPFATKBEMQZ-UHFFFAOYSA-N
PEG
Query on PEG

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CA [auth B]
J [auth A]
K [auth A]
N [auth A]
P [auth A]
CA [auth B],
J [auth A],
K [auth A],
N [auth A],
P [auth A],
V [auth A],
W [auth A]
DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
ZN (Subject of Investigation/LOI)
Query on ZN

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AA [auth B],
H [auth A]
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
EDO
Query on EDO

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L [auth A],
O [auth A],
Q [auth A]
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
ACT
Query on ACT

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GA [auth B],
S [auth A],
T [auth A],
U [auth A]
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
CA
Query on CA

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BA [auth B]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
CL
Query on CL

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HA [auth B],
X [auth A]
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
NA
Query on NA

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I [auth A]SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free:  0.210 (Depositor), 0.219 (DCC) 
  • R-Value Work:  0.166 (Depositor), 0.175 (DCC) 
Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 72.84α = 88.451
b = 77.997β = 64.62
c = 81.707γ = 74.697
Software Package:
Software NamePurpose
REFMACrefinement
DIALSdata reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Biotechnology and Biological Sciences Research Council (BBSRC)United KingdomBB/X001032/1

Revision History  (Full details and data files)

  • Version 1.0: 2025-09-03
    Type: Initial release