5E29

Crystal Structure of Deoxygenated Hemoglobin in Complex with an Allosteric Effector and Nitric Oxide

  • Classification: OXYGEN TRANSPORT
  • Organism(s): Homo sapiens
  • Mutation(s): No 

  • Deposited: 2015-09-30 Released: 2015-10-14 
  • Deposition Author(s): Safo, M.K., Deshpande, T.M.
  • Funding Organization(s): National Institutes of Health/National Institute on Minority Health and Health Disparities (NIH/NIMHD)

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.205 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.6 of the entry. See complete history


Literature

Design, Synthesis, and Investigation of Novel Nitric Oxide (NO)-Releasing Prodrugs as Drug Candidates for the Treatment of Ischemic Disorders: Insights into NO-Releasing Prodrug Biotransformation and Hemoglobin-NO Biochemistry.

Xu, G.G.Deshpande, T.M.Ghatge, M.S.Mehta, A.Y.Omar, A.S.Ahmed, M.H.Venitz, J.Abdulmalik, O.Zhang, Y.Safo, M.K.

(2015) Biochemistry 54: 7178-7192

  • DOI: https://doi.org/10.1021/acs.biochem.5b01074
  • Primary Citation of Related Structures:  
    5E29

  • PubMed Abstract: 

    We have developed novel nitric oxide (NO)-releasing prodrugs of efaproxiral (RSR13) for their potential therapeutic applications in a variety of diseases with underlying ischemia. RSR13 is an allosteric effector of hemoglobin (Hb) that decreases the protein's affinity for oxygen, thereby increasing tissue oxygenation. NO, because of its vasodilatory property, in the form of ester prodrugs has been found to be useful in managing several cardiovascular diseases by increasing blood flow and oxygenation in ischemic tissues. We synthesized three NO-donor ester derivatives of RSR13 (DD-1, DD-2, and DD-3) by attaching the NO-releasing moieties nitrooxyethyl, nitrooxypropyl, and 1-(pyrrolidin-1-yl)diazen-1-ium-1,2-diolate, respectively, to the carboxylate of RSR13. In vitro studies demonstrated that the compounds released NO in a time-dependent manner upon being incubated with l-cysteine (1.8-9.3%) or human serum (2.3-52.5%) and also reduced the affinity of Hb for oxygen in whole blood (ΔP50 of 4.9-21.7 mmHg vs ΔP50 of 25.4-32.1 mmHg for RSR13). Crystallographic studies showed RSR13, the hydrolysis product of the reaction between DD-1 and deoxygenated Hb, bound to the central water cavity of Hb. Also, the hydrolysis product, NO, was observed exclusively bound to the two α hemes, the first such HbNO structure to be reported, capturing the previously proposed physiological bis-ligated nitrosylHb species. Finally, nitrate was observed bound to βHis97. Ultraperformance liquid chromatography-mass spectrometry analysis of the compounds incubated with matrices used for the various studies demonstrated the presence of the predicted reaction products. Our findings, beyond the potential therapeutic application, provide valuable insights into the biotransformation of NO-releasing prodrugs and their mechanism of action and into hemoglobin-NO biochemistry at the molecular level.


  • Organizational Affiliation

    Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University , Alsulaymanyah, Jeddah 21589, Saudi Arabia.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Hemoglobin subunit alpha
A, C
141Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for P69905 (Homo sapiens)
Explore P69905 
Go to UniProtKB:  P69905
PHAROS:  P69905
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP69905
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Hemoglobin subunit beta
B, D
145Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for P68871 (Homo sapiens)
Explore P68871 
Go to UniProtKB:  P68871
PHAROS:  P68871
GTEx:  ENSG00000244734 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP68871
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 6 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download Ideal Coordinates CCD File 
F [auth A],
I [auth B],
M [auth C],
N [auth D]
PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
5JN
Query on 5JN

Download Ideal Coordinates CCD File 
G [auth A]2-(nitrooxy)ethyl 2-(4-{2-[(3,5-dimethylphenyl)amino]-2-oxoethyl}phenoxy)-2-methylpropanoate
C22 H26 N2 O7
TVDZEGBJVSYGIU-UHFFFAOYSA-N
RQ3
Query on RQ3

Download Ideal Coordinates CCD File 
H [auth A],
J [auth B]
2-{4-[(3,5-DIMETHYLANILINO)-CARBONYL-METHYL]-PHENOXY}-2-METHYLPROPIONIC ACID
C20 H23 N O4
BNFRJXLZYUTIII-UHFFFAOYSA-N
CAC
Query on CAC

Download Ideal Coordinates CCD File 
O [auth D]CACODYLATE ION
C2 H6 As O2
OGGXGZAMXPVRFZ-UHFFFAOYSA-M
NO3
Query on NO3

Download Ideal Coordinates CCD File 
K [auth B],
P [auth D]
NITRATE ION
N O3
NHNBFGGVMKEFGY-UHFFFAOYSA-N
NO
Query on NO

Download Ideal Coordinates CCD File 
E [auth A],
L [auth C]
NITRIC OXIDE
N O
ODUCDPQEXGNKDN-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.205 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 95.878α = 90
b = 98.419β = 90
c = 65.444γ = 90
Software Package:
Software NamePurpose
d*TREKdata scaling
CNSrefinement
PDB_EXTRACTdata extraction
d*TREKdata reduction
PHENIXphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute on Minority Health and Health Disparities (NIH/NIMHD)United StatesMD009124

Revision History  (Full details and data files)

  • Version 1.0: 2015-10-14
    Type: Initial release
  • Version 1.1: 2015-12-02
    Changes: Database references
  • Version 1.2: 2015-12-30
    Changes: Database references
  • Version 1.3: 2017-09-13
    Changes: Author supporting evidence, Database references, Derived calculations
  • Version 1.4: 2017-11-22
    Changes: Refinement description
  • Version 1.5: 2019-12-18
    Changes: Author supporting evidence
  • Version 1.6: 2023-09-27
    Changes: Data collection, Database references, Derived calculations, Refinement description