Active-Site Structure Analysis of Recombinant Human Inducible Nitric Oxide Synthase Using Imidazole

Biochemistry ◽  
1996 ◽  
Vol 35 (29) ◽  
pp. 9567-9575 ◽  
Author(s):  
Renee M. Chabin ◽  
Ermenegilda McCauley ◽  
Jimmy R. Calaycay ◽  
Theresa M. Kelly ◽  
Karen L. MacNaul ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Structure Analysis ◽  
Inducible Nitric Oxide Synthase ◽  
Active Site ◽  
Site Structure ◽  
Active Site Structure ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Kinetics of CO binding to the haem domain of murine inducible nitric oxide synthase: differential effects of haem domain ligands

2001 ◽  
Vol 358 (1) ◽  
pp. 201-208 ◽  
Author(s):  
Thirza H. STEVENSON ◽  
Aldo F. GUTIERREZ ◽  
Wendy K. ALDERTON ◽  
Lu-yun LIAN ◽  
Nigel S. SCRUTTON
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Inducible Nitric Oxide Synthase ◽  
Active Site ◽  
Type I ◽  
Geminate Recombination ◽  
Oxygenase Domain ◽  
Oxide Synthase ◽  
Haem Iron ◽  
Inducible Nitric Oxide

The binding of CO to the murine inducible nitric oxide synthase (iNOS) oxygenase domain has been studied by laser flash photolysis. The effect of the (6R)-5,6,7,8-tetrahydro-l-biopterin (BH4) cofactor l-arginine and several Type I l-arginine analogues/ligands on the rates of CO rebinding has been evaluated. The presence of BH4 in the iNOS active site has little effect on the rebinding of protein-caged haem–CO pairs (geminate recombination), but decreases the bimolecular association rates 2-fold. Addition of l-arginine to the BH4-bound complex completely abolishes geminate recombination and results in a further 80-fold decrease in the overall rate of bimolecular association. Three of the Type I ligands, S-ethylisothiourea, l-canavanine and 2,5-lutidine, displaced the CO from the haem iron upon addition to the iNOS oxygenase domain. The Type I ligands significantly decreased the rate of bimolecular binding of CO to the haem iron after photolysis. Most of these ligands also completely abolished geminate recombination. These results are consistent with a relatively open distal pocket that allows CO to bind unhindered in the active site of murine iNOS in the absence of l-arginine or BH4. In the presence of BH4 and l-arginine, however, the enzyme adopts a more closed structure that can greatly reduce ligand access to the haem iron. These observations are discussed in terms of the known structure of iNOS haem domain and solution studies of ligand binding in iNOS and neuronal NOS isoenzymes.

289: Roles of Inducible Nitric Oxide Synthase in Voiding Function and Bladder Pain During Experimental Cystitis

2006 ◽  
Vol 175 (4S) ◽  
pp. 96-96
Author(s):  
Masayoshi Nomura ◽  
Hisae Nishii ◽  
Masato Tsutsui ◽  
Naohiro Fujimoto ◽  
Tetsuro Matsumoto
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Inducible Nitric Oxide Synthase ◽  
Voiding Function ◽  
Bladder Pain ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Search for Potential Inducible Nitric Oxide Synthase Inhibitors with Favorable ADMET Profiles for the Therapy of Helicobacter pylori Infections

2020 ◽  
Vol 19 (30) ◽  
pp. 2795-2804 ◽  
Author(s):  
Ricardo Pereira Rodrigues ◽  
Juliana Santa Ardisson ◽  
Rita de Cássia Ribeiro Gonçalves ◽  
Tiago Branquinho Oliveira ◽  
Vinicius Barreto da Silva ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Helicobacter Pylori ◽  
Nitric Oxide Synthase ◽  
Inducible Nitric Oxide Synthase ◽  
Crucial Role ◽  
Chemical Space ◽  
Target Selection ◽  
Oxide Synthase ◽  
Inos Inhibition ◽  
Inducible Nitric Oxide

Background: Helicobacter pylori is a gram-negative bacterium related to chronic gastritis, peptic ulcer and gastric carcinoma. During its infection process, promotes excessive inflammatory response, increasing the release of reactive species and inducing the production of pro-inflammatory mediators. Inducible Nitric Oxide Synthase (iNOS) plays a crucial role in the gastric carcinogenesis process and a key mediator of inflammation and host defense systems, which is expressed in macrophages induced by inflammatory stimuli. In chronic diseases such as Helicobacter pylori infections, the overproduction of NO due to the prolonged induction of iNOS is of major concern. Objective: In this sense, the search for potential iNOS inhibitors is a valuable strategy in the overall process of Helicobacter pylori pathogeny. Method: In silico techniques were applied in the search of interesting compounds against Inducible Nitric Oxide Synthase enzyme in a chemical space of natural products and derivatives from the Analyticon Discovery databases. Results: The five compounds with the best iNOS inhibition profile were selected for activity and toxicity predictions. Compound 9 (CAS 88198-99-6) displayed significant potential for iNOS inhibition, forming hydrogen bonds with residues from the active site and an ionic interaction with heme. This compound also displayed good bioavailability and absence of toxicity/or from its probable metabolites. Conclusion: The top-ranked compounds from the virtual screening workflow show promising results regarding the iNOS inhibition profile. The results evidenced the importance of the ionic bonding during docking selection, playing a crucial role in binding and positioning during ligand-target selection for iNOS.

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