7TS3

Structure of human neuronal nitric oxide synthase R354A/G357D mutant heme domain in complex with 6-(3-(3,3-difluoroazetidin-1-yl)prop-1-yn-1-yl)-4-methylpyridin-2-amine


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.201 
  • R-Value Observed: 0.204 

Starting Model: experimental
View more details

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.1 of the entry. See complete history


Literature

2-Aminopyridines with a shortened amino sidechain as potent, selective, and highly permeable human neuronal nitric oxide synthase inhibitors.

Vasu, D.Li, H.Hardy, C.D.Poulos, T.L.Silverman, R.B.

(2022) Bioorg Med Chem 69: 116878-116878

  • DOI: https://doi.org/10.1016/j.bmc.2022.116878
  • Primary Citation of Related Structures:  
    7TS1, 7TS2, 7TS3, 7TS4, 7TS5, 7TS6, 7TS7, 7TS8, 7TS9, 7TSA, 7TSB, 7TSC, 7TSD, 7TSE, 7TSF, 7TSG, 7TSH, 7TSI, 7TSK, 7TSL, 7TSM, 7TSN, 7TSO, 7TSP, 7UAM, 7UAN, 7UAO, 7US7, 7US8

  • PubMed Abstract: 

    A series of potent, selective, and highly permeable human neuronal nitric oxide synthase inhibitors (hnNOS) based on the 2-aminopyridine scaffold with a shortened amino sidechain is reported. A rapid and simple protocol was developed to access these inhibitors in excellent yields. Neuronal nitric oxide synthase (nNOS) is a novel therapeutic target for the treatment of various neurological disorders. The major challenges in designing nNOS inhibitors in humans focus on potency, selectivity over other isoforms of nitric oxide synthases (NOSs), and blood-brain barrier permeability. In this context, we discovered a promising inhibitor, 6-(3-(4,4-difluoropiperidin-1-yl)propyl)-4-methylpyridin-2-amine dihydrochloride, that exhibits excellent potency for rat (K i  = 46 nM) and human nNOS (K i  = 48 nM), respectively, with 388-fold human eNOS and 135-fold human iNOS selectivity. It also displayed excellent permeability (P e  = 17.3 × 10 -6 cm s -1 ) through a parallel artificial membrane permeability assay, a model for blood-brain permeability. We found that increasing lipophilicity by incorporation of fluorine atoms on the backbone of the inhibitors significantly increased potential blood-brain barrier permeability. In addition to measuring potency, isoform selectivity, and permeability of NOS inhibitors, we also explored structure-activity relationships via structures of key inhibitors complexed to various isoforms of nitric oxide synthases.


  • Organizational Affiliation

    Department of Chemistry, Department of Molecular Biosciences, Chemistry of Life Processes Institute, Center for Developmental Therapeutics, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113, United States.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Nitric oxide synthase, brain
A, B, C, D
423Homo sapiensMutation(s): 2 
Gene Names: NOS1
EC: 1.14.13.39
UniProt & NIH Common Fund Data Resources
Find proteins for P29475 (Homo sapiens)
Explore P29475 
Go to UniProtKB:  P29475
PHAROS:  P29475
GTEx:  ENSG00000089250 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP29475
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 
E [auth A],
K [auth B],
O [auth C],
U [auth D]
PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
H4B
Query on H4B

Download Ideal Coordinates CCD File 
F [auth A],
L [auth B],
P [auth C],
V [auth D]
5,6,7,8-TETRAHYDROBIOPTERIN
C9 H15 N5 O3
FNKQXYHWGSIFBK-RPDRRWSUSA-N
K7U (Subject of Investigation/LOI)
Query on K7U

Download Ideal Coordinates CCD File 
G [auth A],
M [auth B],
Q [auth C],
W [auth D]
6-[3-(3,3-difluoroazetidin-1-yl)prop-1-yn-1-yl]-4-methylpyridin-2-amine
C12 H13 F2 N3
OJUWVNWEQOIPOJ-UHFFFAOYSA-N
GOL
Query on GOL

Download Ideal Coordinates CCD File 
H [auth A]
I [auth A]
N [auth B]
R [auth C]
S [auth C]
H [auth A],
I [auth A],
N [auth B],
R [auth C],
S [auth C],
X [auth D]
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
ZN
Query on ZN

Download Ideal Coordinates CCD File 
J [auth A],
T [auth C]
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
Binding Affinity Annotations 
IDSourceBinding Affinity
K7U BindingDB:  7TS3 Ki: 488 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.201 
  • R-Value Observed: 0.204 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 52.009α = 90
b = 163.977β = 90
c = 117.315γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
Aimlessdata scaling
PDB_EXTRACTdata extraction
XDSdata reduction
REFMACphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM57353

Revision History  (Full details and data files)

  • Version 1.0: 2022-07-13
    Type: Initial release
  • Version 1.1: 2023-10-18
    Changes: Data collection, Refinement description