4KCI | pdb_00004kci

Structure of neuronal nitric oxide synthase heme domain in complex with N,N'-(ethane-1,2-diylbis(3,1-phenylene))bis(thiophene-2-carboximidamide)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.27 Å
  • R-Value Free: 
    0.238 (Depositor), 0.235 (DCC) 
  • R-Value Work: 
    0.181 (Depositor) 
  • R-Value Observed: 
    0.184 (Depositor) 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

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Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history

Literature

Potent and Selective Double-Headed Thiophene-2-carboximidamide Inhibitors of Neuronal Nitric Oxide Synthase for the Treatment of Melanoma.

Huang, H.Li, H.Yang, S.Chreifi, G.Martasek, P.Roman, L.J.Meyskens, F.L.Poulos, T.L.Silverman, R.B.

(2014) J Med Chem 57: 686-700

  • DOI: https://doi.org/10.1021/jm401252e
  • Primary Citation Related Structures: 
    4KCH, 4KCI, 4KCJ, 4KCK, 4KCL, 4KCM, 4KCN, 4KCO, 4KCP, 4KCQ, 4KCR, 4KCS

  • PubMed Abstract: 

    Selective inhibitors of neuronal nitric oxide synthase (nNOS) are regarded as valuable and powerful agents with therapeutic potential for the treatment of chronic neurodegenerative pathologies and human melanoma. Here, we describe a novel hybrid strategy that combines the pharmacokinetically promising thiophene-2-carboximidamide fragment and structural features of our previously reported potent and selective aminopyridine inhibitors. Two inhibitors, 13 and 14, show low nanomolar inhibitory potency (Ki = 5 nM for nNOS) and good isoform selectivities (nNOS over eNOS [440- and 540-fold, respectively] and over iNOS [260- and 340-fold, respectively]). The crystal structures of these nNOS-inhibitor complexes reveal a new hot spot that explains the selectivity of 14 and why converting the secondary to tertiary amine leads to enhanced selectivity. More importantly, these compounds are the first highly potent and selective nNOS inhibitory agents that exhibit excellent in vitro efficacy in melanoma cell lines.


  • Organizational Affiliation
    • Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States.

Macromolecule Content 

  • Total Structure Weight: 100.39 kDa 
  • Atom Count: 6,969 
  • Modeled Residue Count: 818 
  • Deposited Residue Count: 844 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Nitric oxide synthase, brain
A, B
422Rattus norvegicusMutation(s): 0 
Gene Names: Nos1Bnos
EC: 1.14.13.39
UniProt
Find proteins for P29476 (Rattus norvegicus)
Explore P29476 
Go to UniProtKB:  P29476
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP29476
Sequence Annotations
Expand
Reference Sequence

Small Molecules

Ligands 5 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
HEM

Query on HEM



Download:Ideal Coordinates CCD File
C [auth A],
H [auth B]
PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
1QE

Query on 1QE



Download:Ideal Coordinates CCD File
F [auth A],
J [auth B]
N,N'-(ethane-1,2-diyldibenzene-3,1-diyl)dithiophene-2-carboximidamide
C24 H22 N4 S2
MNMWXAHXXVXJBB-UHFFFAOYSA-N
H4B

Query on H4B



Download:Ideal Coordinates CCD File
D [auth A],
I [auth B]
5,6,7,8-TETRAHYDROBIOPTERIN
C9 H15 N5 O3
FNKQXYHWGSIFBK-RPDRRWSUSA-N
ZN

Query on ZN



Download:Ideal Coordinates CCD File
G [auth A]ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
ACT

Query on ACT



Download:Ideal Coordinates CCD File
E [auth A],
K [auth B]
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
Binding Affinity Annotations 
IDSourceBinding Affinity
1QE BindingDB:  4KCI Ki: 739 (nM) from 1 assay(s)

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.27 Å
  • R-Value Free:  0.238 (Depositor), 0.235 (DCC) 
  • R-Value Work:  0.181 (Depositor) 
  • R-Value Observed: 0.184 (Depositor) 
Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.819α = 90
b = 111.887β = 90
c = 164.961γ = 90
Software Package:
Software NamePurpose
Blu-Icedata collection
REFMACrefinement
HKL-2000data reduction
SCALEPACKdata scaling
REFMACphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-02-12
    Type: Initial release
  • Version 1.1: 2014-02-26
    Changes: Database references
  • Version 1.2: 2017-11-15
    Changes: Refinement description
  • Version 1.3: 2023-09-20
    Changes: Data collection, Database references, Derived calculations, Refinement description