9QAS | pdb_00009qas

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 
    0.213 (Depositor), 0.218 (DCC) 
  • R-Value Work: 
    0.169 (Depositor), 0.177 (DCC) 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

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Ligand Structure Quality Assessment 


This is version 1.1 of the entry. See complete history

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.

(2026) FEBS J 293: 475-491

  • DOI: https://doi.org/10.1111/febs.70232
  • Primary Citation 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.

Macromolecule Content 

  • Total Structure Weight: 146.11 kDa 
  • Atom Count: 11,028 
  • Modeled Residue Count: 1,207 
  • Deposited Residue Count: 1,218 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  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: 2Go to GlyGen: P12821-1
Sequence Annotations
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Reference Sequence

Oligosaccharides

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Entity ID: 2
MoleculeChains Length2D Diagram GlycosylationD 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-glucopyranoseC [auth F]4N-Glycosylation
Glycosylation Resources
GlyTouCan: G32152BH
GlyCosmos: G32152BH
GlyGen: G32152BH
Entity ID: 3
MoleculeChains Length2D Diagram GlycosylationD Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranoseD [auth G],
F [auth I]
3N-Glycosylation
Glycosylation Resources
GlyTouCan: G21290RB
GlyCosmos: G21290RB
GlyGen: G21290RB
Entity ID: 4
MoleculeChains Length2D Diagram GlycosylationD Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranoseE [auth H]2N-Glycosylation
Glycosylation Resources
GlyTouCan: G42666HT
GlyCosmos: G42666HT
GlyGen: G42666HT
Entity ID: 5
MoleculeChains Length2D Diagram GlycosylationD Interactions
alpha-L-fucopyranose-(1-6)-2-acetamido-2-deoxy-beta-D-glucopyranoseG [auth J]2N-Glycosylation
Glycosylation Resources
GlyTouCan: G86851RC
GlyCosmos: G86851RC
GlyGen: G86851RC

Small Molecules

Ligands 9 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
X93
(Subject of Investigation/LOI)

Query on X93



Download:Ideal Coordinates CCD File
K [auth A],
Z [auth B]
TRANDOLAPRILAT
C22 H30 N2 O5
AHYHTSYNOHNUSH-HXFGRODQSA-N
PG4

Query on PG4



Download:Ideal Coordinates CCD File
AA [auth B],
H [auth A]
TETRAETHYLENE GLYCOL
C8 H18 O5
UWHCKJMYHZGTIT-UHFFFAOYSA-N
PGE

Query on PGE



Download:Ideal Coordinates CCD File
P [auth A],
W [auth B]
TRIETHYLENE GLYCOL
C6 H14 O4
ZIBGPFATKBEMQZ-UHFFFAOYSA-N
PEG

Query on PEG



Download:Ideal Coordinates CCD File
BA [auth B],
J [auth A],
Q [auth A],
X [auth B],
Y [auth B]
DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
ZN
(Subject of Investigation/LOI)

Query on ZN



Download:Ideal Coordinates CCD File
CA [auth B],
S [auth A]
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
EDO

Query on EDO



Download:Ideal Coordinates CCD File
L [auth A],
M [auth A],
N [auth A],
O [auth A],
R [auth A]
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
ACT

Query on ACT



Download:Ideal Coordinates CCD File
I [auth A]ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
CA

Query on CA



Download:Ideal Coordinates CCD File
EA [auth B],
U [auth A],
V [auth A]
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
CL

Query on CL



Download:Ideal Coordinates CCD File
DA [auth B],
T [auth A]
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M

Biologically Interesting Molecules (External Reference) 

1 Unique

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free:  0.213 (Depositor), 0.218 (DCC) 
  • R-Value Work:  0.169 (Depositor), 0.177 (DCC) 
Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 73.18α = 88.469
b = 77.6β = 64.397
c = 82.461γ = 74.767
Software Package:
Software NamePurpose
REFMACrefinement
DIALSdata reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


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
  • Version 1.1: 2026-01-28
    Changes: Database references