Untitled

Fischmann, Thierry O.; Hruza, Alan; Niu, Xiao Da; Fossetta, James; Lunn, Charles A.; Dolphin, Edward; Prongay, Andrew; Reichert, Paul; Lundell, Daniel; Narula, Satwant K.; Weber, Patricia C

doi:10.1038/6675

Cited by 444 publications

(325 citation statements)

References 42 publications

Supporting

Mentioning

312

Contrasting

Unclassified

Order By: Relevance

“…5 Investigation into the synthesis and chemistry of novel isoform-selective NOS inhibitors has been an ongoing challenge, even though the general pharmacophore requirements are well established. [6][7][8][9][10][11][12] Synthesis of substrate (L-arginine) based peptidomimetic non-selective as well as selective nNOS inhibitors have been extensively reported in the literature. 13 In an effort to improve PK/PD properties by decreasing their peptidic nature, various small molecule selective nNOS inhibitors have also been reported.…”

mentioning

confidence: 99%

1,5-Disubstituted indole derivatives as selective human neuronal nitric oxide synthase inhibitors

Renton¹,

Speed²,

Maddaford³

et al. 2011

Bioorganic & Medicinal Chemistry Letters

View full text Add to dashboard Cite

A series of 1,6-disubstituted indole derivatives was designed, synthesized and evaluated as inhibitors of human nitric oxide synthase (NOS). By varying the basic amine side chain at the 1-position of the indole ring, several potent and selective inhibitors of human neuronal NOS were identified. In general compounds with bulkier side chains displayed increased selectivity for nNOS over eNOS and iNOS isoforms. One of the compounds, (R)-8 was shown to reduce tactile hyperesthesia (allodynia) after oral administration (30 mg/kg) in an in vivo rat model of dural inflammation relevant to migraine pain. Keywords1,6-Disubstitued indole derivatives; Nitric oxide; Nitric oxide synthase; Nitric oxide synthase inhibitors; Selective neuronal nitric oxide synthase inhibitors Nitric oxide (NO) is an inorganic free radical that has diverse roles both in normal and pathological processes, including the regulation of blood pressure, neurotransmission and macrophage defense systems. 1 NO is synthesized from the enzyme catalysis of L-arginine to L-citrulline by three isoforms of nitric oxide synthase (NOS): two constitutive forms in neuronal cells (nNOS) and endothelial cells (eNOS), and an inducible form in macrophage cells (iNOS). Overstimulation or overproduction of NO by nNOS and iNOS has been shown to play a key role in several disorders, including septic shock, arthritis, diabetes, ischemiareperfusion injury, pain and various neurodegenerative diseases. 2 However, any inhibitors to treat these conditions must avoid eNOS inhibition as this will lead to unwanted effects such as enhanced white cell and platelet activation, hypertension and atherogenesis. 3 Therefore, the development of selective NOS inhibitors is of considerable interest, both from a therapeutic perspective and also as specific pharmacological tools. 4 Although there is low homology among the three NOS primary sequences (~50%), the active sites of the enzymes appears to be relatively conserved with 16 out of 18 residues within 6 Å being identical, presumably explains the difficulty obtaining selective NOS The pharmacophore model we adopted for the arginine binding site of the NOS enzyme includes a guanidine isosteric group (amidine group) and a basic amine group, both attached to a central aryl scaffold (indole core) as shown in Figure 1. 4,15 The amidine group makes an important bidentate interaction with the conserved glutamic acid residue to achieve the necessary potency; whereas the basic amine is assumed to provide the nNOS isoform selectivity. 15 Our design strategy is based on an indole core as an aryl scaffold and exploring various basic amine side chains for achieving the NOS isoform selectivity. As part of our ongoing efforts to find small molecule selective nNOS inhibitors for treating CNS disorders, herein we report the synthesis and biological activity evaluations of a series of 1,6-disubstituted indole derivatives and in vivo activity of (R)-8 in a rat model relevant to migraine pain. 15 Two general approaches were undertaken for the prepa...

show abstract

mentioning

confidence: 99%

1,5-Disubstituted indole derivatives as selective human neuronal nitric oxide synthase inhibitors

Renton¹,

Speed²,

Maddaford³

et al. 2011

Bioorganic & Medicinal Chemistry Letters

View full text Add to dashboard Cite

show abstract

“…NOSred bears strong sequence and functional similarity to NADPH-cytochrome P450 reductase and related electron transfer flavoproteins (9,10), and function to transfer NADPHderived electrons to the ferric heme for O 2 activation during NO synthesis. In contrast, NOSoxy and cytochromes P450 have completely different primary, secondary, and tertiary structures, even though both enzyme families use a thiolate-ligated heme for O 2 activation (11,12). Moreover, unlike P450s, NOSoxy must dimerize to become active (13,14).…”

mentioning

confidence: 99%

Cloning, expression, and characterization of a nitric oxide synthase protein from Deinococcus radiodurans

Adak

Bilwes

Panda

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

122

139

View full text Add to dashboard Cite

We cloned, expressed, and characterized a hemeprotein from Deinococcus radiodurans (D. radiodurans NO synthase, deiNOS) whose sequence is 34% identical to the oxygenase domain of mammalian NO synthases (NOSoxys). deiNOS was dimeric, bound substrate Arg and cofactor tetrahydrobiopterin, and had a normal heme environment, despite its missing N-terminal structures that in NOSoxy bind Zn 2؉ and tetrahydrobiopterin and help form an active dimer. The deiNOS heme accepted electrons from a mammalian NOS reductase and generated NO at rates that met or exceeded NOSoxy. Activity required bound tetrahydrobiopterin or tetrahydrofolate and was linked to formation and disappearance of a typical heme-dioxy catalytic intermediate. Thus, bacterial NOS-like proteins are surprisingly similar to mammalian NOSs and broaden our perspective of NO biochemistry and function.G enes coding for NO synthases (NOSs, EC 4.14.23) are present throughout the plant and animal kingdom. NOS activities are present in plants and lower eukaryotes (1-5). Their primary structures and activities are strikingly similar to the mammalian NOSs, suggesting that NO has been important throughout evolution. All eukaryotic NOSs catalyze the NADPH-and O 2 -dependent oxidation of L-arginine (Arg) to citrulline and NO, with N-hydroxy-L-arginine (NOHA) formed as an enzyme-bound intermediate (6). Structurally, all animal NOSs are bi-domain proteins containing an N-terminal oxygenase domain (NOSoxy) that binds protoporphyrin IX (heme), 6R-tetrahydrobiopterin (H 4 B), and Arg and is linked to a C-terminal f lavoprotein domain (NOS reductase domain, NOSred) by a central calmodulin (CaM) binding sequence (7,8). NOSred bears strong sequence and functional similarity to NADPH-cytochrome P450 reductase and related electron transfer flavoproteins (9, 10), and function to transfer NADPHderived electrons to the ferric heme for O 2 activation during NO synthesis. In contrast, NOSoxy and cytochromes P450 have completely different primary, secondary, and tertiary structures, even though both enzyme families use a thiolate-ligated heme for O 2 activation (11, 12). Moreover, unlike P450s, NOSoxy must dimerize to become active (13,14). Dimerization produces functional binding sites for Arg and H 4 B and sequesters the heme catalytic center from solvent. These distinguishing features imply that NOSs evolved separately from other heme-thiolate enzymes and can so provide unique perspectives on their structure-function relationships.Although oxidative (nitrification) or reductive (denitrification) pathways for prokaryote NO biosynthesis are well established (15), there have been few reports on NOS-like proteins in bacteria (16,17). To date no prokaryotic NOS proteins have been completely sequenced, purified, or cloned. However, some have been shown to have nitrite-forming activity that depended on Arg, NADPH, and H 4 B. More recent genome sequencing of Bacillus subtilis, Deinococcus radiodurans, and other bacteria (18)(19)(20) confirm that a subset contain ORFs that code for proteins homo...

show abstract

“…The localization, enzymology, regulation, and structural and functional aspects of the NOS family have been comprehensively reviewed (14,18,19). The search for differences in the oxygenase domains among the different NOS isoforms led to the elucidation of the heme domain structures of all three (18,(20)(21)(22). The remarkable similarity of these structures has redirected the interest of our laboratory (14,15,(23)(24)(25) and the laboratories of others (26)(27)(28)(29) to the role of the flavoprotein domains of NOS isoforms in their intrinsic and extrinsic regulation.…”

mentioning

confidence: 99%

Recruitment of governing elements for electron transfer in the nitric oxide synthase family

Jáchymová

Martásek

Panda

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

At least three building blocks are responsible for the molecular basis of the modulation of electron transfer in nitric oxide synthase (NOS) isoforms: the calmodulin-binding sequence, the C-terminal extension, and the autoregulatory loop in the reductase domain. We have attempted to impart the control conferred by the C termini of NOS to cytochrome P450 oxidoreductase (CYPOR), which contains none of these regulatory elements. The effect of these C termini on the properties of CYPOR sheds light on the possible evolutionary origin of NOS and addresses the recruitment of new peptides on the development of new functions for CYPOR. The C termini of NOSs modulate flavoprotein-mediated electron transfer to various electron acceptors. The reduction of the artificial electron acceptors cytochrome c, 2,6-dichlorophenolindophenol, and ferricyanide was inhibited by the addition of any of these C termini to CYPOR, whereas the reduction of molecular O 2 was increased. This suggests a shift in the rate-limiting step, indicating that the NOS C termini interrupt electron flux between flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) and͞or the electron acceptors. The modulation of CYPOR by the addition of the NOS C termini is also supported by flavin reoxidation and fluorescence-quenching studies and antibody recognition of the C-terminal extension. These experiments support the origin of the NOS enzymes from modules consisting of a heme domain and CYPOR or ferredoxin-NADP ؉ reductase-and flavodoxin-like subdomains that constitute CYPOR, followed by further recruitment of smaller modulating elements into the flavin-binding domains.flavoprotein ͉ NADPH-cytochrome P450 reductase ͉ protein evolution

show abstract

Untitled

Cited by 444 publications

References 42 publications

1,5-Disubstituted indole derivatives as selective human neuronal nitric oxide synthase inhibitors

1,5-Disubstituted indole derivatives as selective human neuronal nitric oxide synthase inhibitors

Cloning, expression, and characterization of a nitric oxide synthase protein from Deinococcus radiodurans

Recruitment of governing elements for electron transfer in the nitric oxide synthase family

Contact Info

Product

Resources

About