Biological Assembly 1  

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Biological Assembly Evidence: homology

Biological Assembly 2  

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 2 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 205.52 kDa 
• Atom Count: 13,616 
• Modelled Residue Count: 1,614 
• Deposited Residue Count: 1,760 
• Unique protein chains: 1

 6NH1

Structure of human endothelial nitric oxide synthase heme domain in complex with 6-(3-fluoro-5-(3-(methylamino)prop-1-yn-1-yl)phenethyl)-4-methylpyridin-2-amine

• PDB DOI:  https://doi.org/10.2210/pdb6NH1/pdb

• Classification: OXIDOREDUCTASE/OXIDOREDUCTASE inhibitor
• Organism(s): Homo sapiens
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2018-12-21 Released: 2019-03-13 
• Deposition Author(s): Chreifi, G., Li, H., Poulos, T.L.
• Funding Organization(s): National Institutes of Health/National Cancer Institute (NIH/NCI)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.22 Å
• R-Value Free: 0.280 
• R-Value Work: 0.212 
• R-Value Observed: 0.215 

Literature

Optimization of Blood-Brain Barrier Permeability with Potent and Selective Human Neuronal Nitric Oxide Synthase Inhibitors Having a 2-Aminopyridine Scaffold.

Do, H.T., Li, H., Chreifi, G., Poulos, T.L., Silverman, R.B.

(2019) J Med Chem 62: 2690-2707

• PubMed: 30802056 
• DOI: https://doi.org/10.1021/acs.jmedchem.8b02032
• Primary Citation of Related Structures:  
  6NG1, 6NG2, 6NG4, 6NG5, 6NG6, 6NG7, 6NG8, 6NGA, 6NGB, 6NGC, 6NGD, 6NGE, 6NGF, 6NGH, 6NGI, 6NGJ, 6NGK, 6NGL, 6NGM, 6NGN, 6NGP, 6NGQ, 6NGR, 6NGS, 6NGT, 6NGU, 6NGV, 6NGW, 6NGX, 6NGY, 6NGZ, 6NH0, 6NH1, 6NH2, 6NH3, 6NH4, 6NH5, 6NH6, 6NH7, 6NH8, 6NHB, 6NHC, 6NHD, 6NHE, 6NHF


• PubMed Abstract: 
  

Effective delivery of therapeutic drugs into the human brain is one of the most challenging tasks in central nervous system drug development because of the blood-brain barrier (BBB). To overcome the BBB, both passive permeability and efflux transporter liability of a compound must be addressed. Herein, we report our optimization related to BBB penetration of neuronal nitric oxide synthase (nNOS) inhibitors toward the development of new drugs for neurodegenerative diseases. Various approaches, including enhancing lipophilicity and rigidity of new inhibitors and modulating the p K _a of amino groups, have been employed. In addition to determining inhibitor potency and selectivity, crystal structures of most newly designed compounds complexed to various nitric oxide synthase isoforms have been determined. We have discovered a new analogue (21), which exhibits not only excellent potency ( K _i < 30 nM) in nNOS inhibition but also a significantly low P-glycoprotein and breast-cancer-resistant protein substrate liability as indicated by an efflux ratio of 0.8 in the Caco-2 bidirectional assay.

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Organizational Affiliation: 

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

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Endothelial nitric oxide synthase splice variant eNOS13A	A, B, C, D	440	Homo sapiens	Mutation(s): 0  Gene Names: NOS3 EC: 1.14.13.39
UniProt & NIH Common Fund Data Resources
Find proteins for P29474 (Homo sapiens) Explore P29474  Go to UniProtKB:  P29474
PHAROS:  P29474

Small Molecules

Ligands 8 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
HEM	E [auth A], HA [auth D], P [auth B], Z [auth C]	PROTOPORPHYRIN IX CONTAINING FE C34 H32 Fe N4 O4 KABFMIBPWCXCRK-RGGAHWMASA-L
KLY	BA [auth C], F [auth A], JA [auth D], R [auth B]	6-(2-{3-fluoro-5-[3-(methylamino)prop-1-yn-1-yl]phenyl}ethyl)-4-methylpyridin-2-amine C18 H20 F N3 YNFSNSWWKPMRND-UHFFFAOYSA-N
H4B	AA [auth C], IA [auth D], O [auth B], Q [auth B]	5,6,7,8-TETRAHYDROBIOPTERIN C9 H15 N5 O3 FNKQXYHWGSIFBK-RPDRRWSUSA-N
BTB	CA [auth C], G [auth A], H [auth A], I [auth A], KA [auth D], LA [auth D], N [auth A], S [auth B], T [auth B], X [auth B], Y [auth B]	2-[BIS-(2-HYDROXY-ETHYL)-AMINO]-2-HYDROXYMETHYL-PROPANE-1,3-DIOL C8 H19 N O5 OWMVSZAMULFTJU-UHFFFAOYSA-N
GD	GA [auth C], M [auth A], MA [auth D], V [auth B]	GADOLINIUM ATOM Gd UIWYJDYFSGRHKR-UHFFFAOYSA-N
GOL	EA [auth C], K [auth A]	GLYCEROL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N
ZN	DA [auth C], J [auth A], OA [auth D], W [auth B]	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N
CL	FA [auth C], L [auth A], NA [auth D], U [auth B]	CHLORIDE ION Cl VEXZGXHMUGYJMC-UHFFFAOYSA-M

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.22 Å
• R-Value Free: 0.280 
• R-Value Work: 0.212 
• R-Value Observed: 0.215 
• Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 59.264	α = 90
b = 152.461	β = 90.73
c = 108.816	γ = 90

Software Package:

Software Name	Purpose
PHENIX	refinement
MOSFLM	data reduction
Aimless	data scaling
REFMAC	phasing

Structure Validation

Entry History & Funding Information

Deposition Data

• Released Date: 2019-03-13 
Deposition Author(s): Chreifi, G., Li, H., Poulos, T.L.

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Funding Organization	Location	Grant Number
National Institutes of Health/National Cancer Institute (NIH/NCI)	United States	GM57353

Revision History  

• Version 1.0: 2019-03-13
  Type: Initial release
  
• Version 1.1: 2019-03-27
  Changes: Data collection, Database references
• Version 1.2: 2019-12-04
  Changes: Author supporting evidence