3N5X

Structure of neuronal nitric oxide synthase heme domain in complex with 4-(2-(5-(2-(6-amino-4-methylpyridin-2-yl)ethyl)pyridin-3-yl)ethyl)-6-methylpyridin-2-amine


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.198 
  • R-Value Work: 0.173 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Role of zinc in isoform-selective inhibitor binding to neuronal nitric oxide synthase .

Delker, S.L.Xue, F.Li, H.Jamal, J.Silverman, R.B.Poulos, T.L.

(2010) Biochemistry 49: 10803-10810

  • DOI: 10.1021/bi1013479
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • In previous studies [Delker, S. L., et al. (2010), J. Am. Chem. Soc. 132, 5437-5442], we determined the crystal structures of neuronal nitric oxide synthase (nNOS) in complex with nNOS-selective chiral pyrrolidine inhibitors, designed to have an amin ...

    In previous studies [Delker, S. L., et al. (2010), J. Am. Chem. Soc. 132, 5437-5442], we determined the crystal structures of neuronal nitric oxide synthase (nNOS) in complex with nNOS-selective chiral pyrrolidine inhibitors, designed to have an aminopyridine group bound over the heme where it can electrostatically interact with the conserved active site Glu residue. However, in addition to the expected binding mode with the (S,S)-cis inhibitors, an unexpected "flipped" orientation was observed for the (R,R)-cis enantiomers. In the flipped mode, the aminopyridine extends out of the active site where it interacts with one heme propionate. This prompted us to design and synthesize symmetric "double-headed" inhibitors with an aminopyridine at each end of a bridging ring structure [Xue, F., Delker, S. L., Li, H., Fang, J., Jamal, J., Martásek, P., Roman, L. J., Poulos, T. L., and Silverman, R. B. Symmetric double-headed aminopyridines, a novel strategy for potent and membrane-permeable inhibitors of neuronal nitric oxide synthase. J. Med. Chem. (submitted for publication)]. One aminopyridine should interact with the active site Glu and the other with the heme propionate. Crystal structures of these double-headed aminopyridine inhibitors in complexes with nNOS show unexpected and significant protein and heme conformational changes induced by inhibitor binding that result in removal of the tetrahydrobiopterin (H(4)B) cofactor and creation of a new Zn(2+) site. These changes are due to binding of a second inhibitor molecule that results in the displacement of H(4)B and the placement of the inhibitor pyridine group in position to serve as a Zn(2+) ligand together with Asp, His, and a chloride ion. Binding of the second inhibitor molecule and generation of the Zn(2+) site do not occur in eNOS. Structural requirements for creation of the new Zn(2+) site in nNOS were analyzed in detail. These observations open the way for the potential design of novel inhibitors selective for nNOS.


    Organizational Affiliation

    Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92697-3900, United States.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Nitric oxide synthase
A, B
422Rattus norvegicusMutation(s): 0 
Gene Names: Nos1 (Bnos)
EC: 1.14.13.39
Find proteins for P29476 (Rattus norvegicus)
Go to UniProtKB:  P29476
Small Molecules
Ligands 5 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
ACT
Query on ACT

Download SDF File 
Download CCD File 
A, B
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
CL
Query on CL

Download SDF File 
Download CCD File 
A, B
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
XFK
Query on XFK

Download SDF File 
Download CCD File 
A, B
6-(2-{5-[2-(2-amino-6-methylpyridin-4-yl)ethyl]pyridin-3-yl}ethyl)-4-methylpyridin-2-amine
C21 H25 N5
RDXKSGCNYFTVRW-UHFFFAOYSA-N
 Ligand Interaction
HEM
Query on HEM

Download SDF File 
Download CCD File 
A, B
PROTOPORPHYRIN IX CONTAINING FE
HEME
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
XFKKi: 103 nM (100) BINDINGDB
XFKKi: 103 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.198 
  • R-Value Work: 0.173 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 52.290α = 90.00
b = 111.100β = 90.00
c = 164.770γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
SCALEPACKdata scaling
HKL-2000data reduction
CNSrefinement
Blu-Icedata collection
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-02-09
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-11-08
    Type: Refinement description