Abstract
In this study, we applied structure-based virtual screening techniques to identify natural product or natural product-like inhibitors of iNOS. The iNOS inhibitory activity of the hit compounds was characterized using cellular assays and an in vivo zebrafish larvae model. The natural product-like compound 1 inhibited NO production in LPS-stimulated Raw264.7 macrophages, without exerting cytotoxic effects on the cells. Significantly, compound 1 was able to reverse MPTP-induced locomotion deficiency and neurotoxicity in an in vivo zebrafish larval model. Hence, compound 1 could be considered as a scaffold for the further development of iNOS inhibitors for potential anti-inflammatory or anti-neurodegenerative applications.
Highlights
Nitric oxide (NO) is a short-lived pleiotropic regulator that plays a diverse variety of roles in living organisms
I) The initial model of inducible NOS (iNOS) was built from an X-ray co-crystal structure of the monomeric oxygenase domain of murine D114 iNOS complexed with an inhibitor (PDB: 1DD7) [21], using the molecular conversion procedure implemented in the Internal Coordinate Mechanics (ICM)-pro 3.6-1d program (Molsoft) [22]
A chemical library containing over 90,000 natural product or natural product-like compounds (ZINC natural product database) was docked to the molecular model of iNOS using the Internal Coordinate Mechanics (ICM) method (Molsoft) [22]
Summary
Nitric oxide (NO) is a short-lived pleiotropic regulator that plays a diverse variety of roles in living organisms. Endogenous NO is produced from L-arginine, oxygen and NADPH, in a series of reactions catalyzed by homodimers of NO synthases (NOS) [3]. The three NOS isoforms share a common structure that is comprised of two major domains. The N-terminal catalytic domain binds the heme prosthetic group, the substrates L-arginine and oxygen, and the redox cofactor 5,6,7,8-tetrahydrobiopterin (H4B), and is linked via a calmodulin-recognition site to a Cterminal reductase domain that contains binding sites for NADPH, FAD and FMN. Aided by the heme group, electrons are transferred from NADPH to oxygen, via the cofactors FAD and FMN [4]. A structural zinc atom exists at the interface region of NOS dimers, and its coordination to two cysteine residues of each subunit has been proposed to stabilize dimer formation [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
