1m8d

inducible nitric oxide synthase with Chlorzoxazone bound

spinqualitylabelsall models 1m8d, resolution 2.35Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1m8d is a 2 chain structure with sequence from Mus musculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: BOG, CLW, EDO, H4B, HEM, SO4 Related: 1nod, 1m8e, 1mih, 1m8i, 1m9j, 1m9k, 1m9m, 1m9q, 1m9r, 1m9t, 3nod Gene: iNOS (Mus musculus) Activity: Nitric-oxide synthase, with EC number 1.14.13.39 Resources: FirstGlance, OCA, RCSB, PDBsum Function [NOS2_MOUSE] Produces nitric oxide (NO) which is a messenger molecule with diverse functions throughout the body. In macrophages, NO mediates tumoricidal and bactericidal actions. Also has nitrosylase activity and mediates cysteine S-nitrosylation of cytoplasmic target proteins such COX2. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Nitric oxide is a key signaling molecule in many biological processes, making regulation of nitric oxide levels highly desirable for human medicine and for advancing our understanding of basic physiology. Designing inhibitors to specifically target one of the three nitric oxide synthase (NOS) isozymes that form nitric oxide from the L-Arg substrate poses a significant challenge due to the overwhelmingly conserved active sites. We report here 10 new X-ray crystallographic structures of inducible and endothelial NOS oxygenase domains cocrystallized with chlorzoxazone and four nitroindazoles: 5-nitroindazole, 6-nitroindazole, 7-nitroindazole, and 3-bromo-7-nitroindazole. Each of these bicyclic aromatic inhibitors has only one hydrogen bond donor and therefore cannot form the bidentate hydrogen bonds that the L-Arg substrate makes with Glu371. Instead, all of these inhibitors induce a conformational change in Glu371, creating an active site with altered molecular recognition properties. The cost of this conformational change is approximately 1-2 kcal, based on our measured constants for inhibitor binding to the wild-type and E371A mutant proteins. These inhibitors derive affinity by pi-stacking above the heme and replacing both intramolecular (Glu371-Met368) and intermolecular (substrate-Trp366) hydrogen bonds to the beta-sheet architecture underlying the active site. When bound to NOS, high-affinity inhibitors in this class are planar, whereas weaker inhibitors are nonplanar. Isozyme differences were observed in the pterin cofactor site, the heme propionate, and inhibitor positions. Computational docking predictions match the crystallographic results, including the Glu371 conformational change and inhibitor-binding orientations, and support a combined crystallographic and computational approach to isozyme-specific NOS inhibitor analysis and design. Conformational changes in nitric oxide synthases induced by chlorzoxazone and nitroindazoles: crystallographic and computational analyses of inhibitor potency.,Rosenfeld RJ, Garcin ED, Panda K, Andersson G, Aberg A, Wallace AV, Morris GM, Olson AJ, Stuehr DJ, Tainer JA, Getzoff ED Biochemistry. 2002 Nov 26;41(47):13915-25. PMID:12437348 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Nitric Oxide Synthase

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