scholarly journals Inducible Nitric Oxide Synthase Requires Both the Canonical Calmodulin-binding Domain and Additional Sequences in Order to Bind Calmodulin and Produce Nitric Oxide in the Absence of Free Ca2+

1996 ◽  
Vol 271 (37) ◽  
pp. 22679-22686 ◽  
Author(s):  
Jia Ruan ◽  
Qiao-wen Xie ◽  
Nancy Hutchinson ◽  
Hearn Cho ◽  
Gloria C. Wolfe ◽  
...  
2020 ◽  
Vol 52 (12) ◽  
pp. 1360-1372
Author(s):  
Jianghong Yan ◽  
Fei-Fei Shang ◽  
An He ◽  
Shupeng Hu ◽  
Suxin Luo ◽  
...  

Abstract Inducible nitric oxide synthase (iNOS) plays critical roles in the inflammatory response and host defense. Previous research on iNOS regulation mainly focused on its gene expression level, and much less is known about the regulation of iNOS function by N-glycosylation. In this study, we report for the first time that iNOS is N-glycosylated in vitro and in vivo. Mass spectrometry studies identified Asn695 as an N-glycosylation site of murine iNOS. Mutating Asn695 to Gln695 yields an iNOS that exhibits greater enzyme activity. The essence of nitric oxide synthase catalytic reaction is electron transfer process, which involves a series of conformational changes, and the linker between the flavin mononucleotide-binding domain and the flavin adenine dinucleotide-binding domain plays vital roles in the conformational changes. Asn695 is part of the linker, so we speculated that attachment of N-glycan to the Asn695 residue might inhibit activity by disturbing electron transfer. Indeed, our NADPH consumption results demonstrated that N-glycosylated iNOS consumes NADPH more slowly. Taken together, our results indicate that iNOS is N-glycosylated at its Asn695 residue and N-glycosylation of Asn695 might suppress iNOS activity by disturbing electron transfer.


2006 ◽  
Vol 175 (4S) ◽  
pp. 96-96
Author(s):  
Masayoshi Nomura ◽  
Hisae Nishii ◽  
Masato Tsutsui ◽  
Naohiro Fujimoto ◽  
Tetsuro Matsumoto

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 ◽  
...  

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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