2DY5

Crystal structure of rat heme oxygenase-1 in complex with heme and 2-[2-(4-chlorophenyl)ethyl]-2-[(1H-imidazol-1-yl)methyl]-1,3-dioxolane


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.70 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.197 

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This is version 1.2 of the entry. See complete history


Literature

X-ray crystallographic and biochemical characterization of the inhibitory action of an imidazole-dioxolane compound on heme oxygenase

Sugishima, M.Higashimoto, Y.Oishi, T.Takahashi, H.Sakamoto, H.Noguchi, M.Fukuyama, K.

(2007) Biochemistry 46: 1860-1867

  • DOI: 10.1021/bi062264p
  • Primary Citation of Related Structures:  
    2DY5

  • PubMed Abstract: 
  • Heme oxygenase (HO) catalyzes the regiospecific cleavage of the porphyrin ring of heme using reducing equivalents and O2 to produce biliverdin, iron, and CO. Because CO has a cytoprotective effect through the p38-MAPK pathway, HO is a potential thera ...

    Heme oxygenase (HO) catalyzes the regiospecific cleavage of the porphyrin ring of heme using reducing equivalents and O2 to produce biliverdin, iron, and CO. Because CO has a cytoprotective effect through the p38-MAPK pathway, HO is a potential therapeutic target in cancer. In fact, inhibition of the HO isoform HO-1 reduces Kaposi sarcoma tumor growth. Imidazole-dioxolane compounds have recently attracted attention because they have been reported to specifically inhibit HO-1, but not HO-2, unlike Cr-containing protoporphyrin IX, a classical inhibitor of HO, that inhibits not only both HO isoforms but also other hemoproteins. The inhibitory mechanism of imidazole-dioxolane compounds, however, has not yet been characterized. Here, we determine the crystal structure of the ternary complex of rat HO-1, heme, and an imidazole-dioxolane compound, 2-[2-(4-chlorophenyl)ethyl]-2-[(1H-imidazol-1-yl)methyl]-1,3-dioxolane. This compound bound on the distal side of the heme iron, where the imidazole and 4-chlorophenyl groups were bound to the heme iron and the hydrophobic cavity in HO, respectively. Binding of the bulky inhibitor in the narrow distal pocket shifted the distal helix to open the distal site and moved both the heme and the proximal helix. Furthermore, the biochemical characterization revealed that the catalytic reactions of both HO-1 and HO-2 were completely stopped after the formation of verdoheme in the presence of the imidazole-dioxolane compound. This result should be mainly due to the lower reactivity of the inhibitor-bound verdoheme with O2 compared to the reactivity of the inhibitor-bound heme with O2.


    Organizational Affiliation

    Department of Medical Biochemistry, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Heme oxygenase 1A267Rattus norvegicusMutation(s): 0 
Gene Names: Hmox1
EC: 1.14.99.3 (PDB Primary Data), 1.14.14.18 (UniProt)
Find proteins for P06762 (Rattus norvegicus)
Explore P06762 
Go to UniProtKB:  P06762
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download CCD File 
A
PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
224
Query on 224

Download CCD File 
A
1-({2-[2-(4-CHLOROPHENYL)ETHYL]-1,3-DIOXOLAN-2-YL}METHYL)-1H-IMIDAZOLE
C15 H17 Cl N2 O2
NPIOYRIZNLPLDH-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
224IC50:  2800   nM  BindingDB
224IC50:  4000   nM  BindingDB
224IC50:  4300   nM  BindingDB
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.70 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.197 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 66.78α = 90
b = 66.78β = 90
c = 121.39γ = 120
Software Package:
Software NamePurpose
HKL-2000data collection
MOLREPphasing
CNSrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-05-22
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance