View source for 6nh4


==Structure of human endothelial nitric oxide synthase heme domain in complex with 6-(3-fluoro-5-(2-((2R,4S)-4-fluoropyrrolidin-2-yl)ethyl)phenethyl)-4-methylpyridin-2-amine==
<StructureSection load='6nh4' size='340' side='right'caption='[[6nh4]], [[Resolution|resolution]] 2.27&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6nh4]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6NH4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6NH4 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.27&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BTB:2-[BIS-(2-HYDROXY-ETHYL)-AMINO]-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>BTB</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=GD:GADOLINIUM+ATOM'>GD</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=H4B:5,6,7,8-TETRAHYDROBIOPTERIN'>H4B</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=KLA:6-[2-(3-fluoro-5-{2-[(2R,4S)-4-fluoropyrrolidin-2-yl]ethyl}phenyl)ethyl]-4-methylpyridin-2-amine'>KLA</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=6nh4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6nh4 OCA], [https://pdbe.org/6nh4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6nh4 RCSB], [https://www.ebi.ac.uk/pdbsum/6nh4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6nh4 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NOS3_HUMAN NOS3_HUMAN] Produces nitric oxide (NO) which is implicated in vascular smooth muscle relaxation through a cGMP-mediated signal transduction pathway. NO mediates vascular endothelial growth factor (VEGF)-induced angiogenesis in coronary vessels and promotes blood clotting through the activation of platelets.<ref>PMID:17264164</ref>   Isoform eNOS13C: Lacks eNOS activity, dominant-negative form that may down-regulate eNOS activity by forming heterodimers with isoform 1.<ref>PMID:17264164</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
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 Ka 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 ( Ki &lt; 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.

Optimization of Blood-Brain Barrier Permeability with Potent and Selective Human Neuronal Nitric Oxide Synthase Inhibitors Having a 2-Aminopyridine Scaffold.,Do HT, Li H, Chreifi G, Poulos TL, Silverman RB J Med Chem. 2019 Feb 25. doi: 10.1021/acs.jmedchem.8b02032. PMID:30802056<ref>PMID:30802056</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6nh4" style="background-color:#fffaf0;"></div>

==See Also==
*[[Nitric Oxide Synthase 3D structures|Nitric Oxide Synthase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Chreifi G]]
[[Category: Li H]]
[[Category: Poulos TL]]