9MWG | pdb_00009mwg

Structure of rat neuronal nitric oxide synthase R349A mutant heme domain bound with N-(4-(2-((3-(thiazole-2-carboximidamido)benzyl)amino)ethyl)phenyl)thiazole-2-carboximidamide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.89 Å
  • R-Value Free: 
    0.243 (Depositor), 0.242 (DCC) 
  • R-Value Work: 
    0.204 (Depositor), 0.207 (DCC) 
  • R-Value Observed: 
    0.206 (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 1.1 of the entry. See complete history

Literature

New Inhibitors of Neuronal Nitric Oxide Synthase for the Treatment of Melanoma.

Awasthi, A.Patel, A.Li, H.Kang, K.M.Hardy, C.D.Ansari, A.Nowar, R.Hasan, M.E.Yang, S.Poulos, T.L.Silverman, R.B.

(2026) J Med Chem 69: 2310-2329

  • DOI: https://doi.org/10.1021/acs.jmedchem.5c02154
  • Primary Citation Related Structures: 
    9MWA, 9MWB, 9MWC, 9MWD, 9MWE, 9MWF, 9MWG, 9MWH, 9MWI, 9MWJ, 9MWK, 9MWL, 9MWM, 9MWN, 9MWO, 9MWP, 9MWQ, 9MWR, 9MWS, 9MWT, 9MWU, 9MWV, 9MWW, 9MWX

  • PubMed Abstract: 

    In 2024, an estimated 100,640 new cases of invasive melanoma were diagnosed in the U.S., with 9290 deaths. Our previous studies revealed that neuronal nitric oxide synthase (nNOS) derived nitric oxide plays a critical role in melanoma progression, making nNOS inhibition a promising strategy. High structural similarity among NOS isoforms requires careful design of nNOS inhibitors to avoid off-target effects. Our previous lead, HH044, demonstrated potent antimelanoma activity but exhibited only moderate nNOS selectivity. Here, we utilized a structure-based approach to design nNOS inhibitors that promote interactions with human nNOS-specific residue His342. Compound 9 exhibited inhibition of both human ( K i = 1.7 nM) and rat nNOS ( K i = 2.3 nM), with 5654-fold selectivity over human eNOS and 250-fold selectivity over iNOS. X-ray crystallography and molecular modeling revealed a novel SAR, forming the basis for nNOS inhibition and providing a foundation for further innovative design of nNOS inhibitors for melanoma treatment.


  • Organizational Affiliation
    • Department of Chemistry, Chemistry of Life Processes Institute, Center for Developmental Therapeutics, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States.

Macromolecule Content 

  • Total Structure Weight: 50.17 kDa 
  • Atom Count: 3,513 
  • Modeled Residue Count: 411 
  • Deposited Residue Count: 422 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Nitric oxide synthase, brain422Rattus norvegicusMutation(s): 1 
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
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Reference Sequence

Small Molecules

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

Query on HEM



Download:Ideal Coordinates CCD File
B [auth A]PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
A1BTV
(Subject of Investigation/LOI)

Query on A1BTV



Download:Ideal Coordinates CCD File
D [auth A]N-[3-({[2-(4-{[(Z)-imino(1,3-thiazol-2-yl)methyl]amino}phenyl)ethyl]amino}methyl)phenyl]-1,3-thiazole-2-carboximidamide
C23 H23 N7 S2
PUUAGBWXELPIEB-UHFFFAOYSA-N
H4B

Query on H4B



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

Query on ZN



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

Query on ACT



Download:Ideal Coordinates CCD File
E [auth A]ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.89 Å
  • R-Value Free:  0.243 (Depositor), 0.242 (DCC) 
  • R-Value Work:  0.204 (Depositor), 0.207 (DCC) 
  • R-Value Observed: 0.206 (Depositor) 
Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 48.108α = 90
b = 113.634β = 90
c = 162.99γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
Aimlessdata scaling
XDSdata reduction
REFMACphasing

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 of General Medical Sciences (NIH/NIGMS)United StatesGM131920

Revision History  (Full details and data files)

  • Version 1.0: 2025-11-26
    Type: Initial release
  • Version 1.1: 2026-04-01
    Changes: Database references