Structural basis for pterin antagonism in nitric-oxide synthase. Development of novel 4-oxo-pteridine antagonists of (6R)-5,6,7,8-tetrahydrobiopterinKotsonis, P., Frohlich, L.G., Raman, C.S., Li, H., Berg, M., Gerwig, R., Groehn, V., Kang, Y., Al-Masoudi, N., Taghavi-Moghadam, S., Mohr, D., Munch, U., Schnabel, J., Martasek, P., Masters, B.S., Strobel, H., Poulos, T., Matter, H., Pfleiderer, W., Schmidt, H.H.
(2001) J.Biol.Chem. 276: 49133-49141
- PubMed: 11590164
- DOI: 10.1074/jbc.M011469200
- Primary Citation of Related Structures:
- PubMed Abstract:
- Crystal Structure of Constitutive Endothelial Nitric Oxide Synthase: A Paradigm for Pterin Function Involving a Novel Metal Center
Raman, C.S.,Li, H.,Martasek, P.,Kral, V.,Masters, B.S.S.,Poulos, T.L.
(1998) Cell 95: 939
- Inhibition of Neuronal Nitric Oxide Synthase by 4-Amino Pteridine Derivatives: Structure-Activity Relationship of Antagonists of (6R)-5,6,7,8- Tetrahydrobiopterin Cofactor
Frohlich, L.G.,Kotsonis, P.,Traub, H.,Taghavi-Moghadam, S.,Al-Masoudi, N.,Hofmann, H.,Strobel, H.,Matter, H.,Pfleiderer, W.,Schmidt, H.H.H.W.
(1999) J.Med.Chem. 42: 4108
- Structure of Nitric Oxide Synthase Oxygenase Dimer with Pterin and Substrate
Crane, B.R.,Arvai, A.S.,Ghosh, D.K.,Wu, C.,Getzoff, E.D.,Stuehr, D.J.,Tainer, A.
(1998) Science 279: 2121
Pathological nitric oxide (NO) generation in sepsis, inflammation, and stroke may be therapeutically controlled by inhibiting NO synthases (NOS). Here we targeted the (6R)-5,6,7,8-tetrahydro-l-biopterin (H(4)Bip)-binding site of NOS, which, upon cofa ...
Pathological nitric oxide (NO) generation in sepsis, inflammation, and stroke may be therapeutically controlled by inhibiting NO synthases (NOS). Here we targeted the (6R)-5,6,7,8-tetrahydro-l-biopterin (H(4)Bip)-binding site of NOS, which, upon cofactor binding, maximally increases enzyme activity and NO production from substrate l-arginine. The first generation of H(4)Bip-based NOS inhibitors employed a 4-amino pharmacophore of H(4)Bip analogous to antifolates such as methotrexate. We developed a novel series of 4-oxo-pteridine derivatives that were screened for inhibition against neuronal NOS (NOS-I) and a structure-activity relationship was determined. To understand the structural basis for pterin antagonism, selected derivatives were docked into the NOS pterin binding cavity. Using a reduced 4-oxo-pteridine scaffold, derivatives with certain modifications such as electron-rich aromatic phenyl or benzoyl groups at the 5- and 6-positions, were discovered to markedly inhibit NOS-I, possibly due to hydrophobic and electrostatic interactions with Phe(462) and Ser(104), respectively, within the pterin binding pocket. One of the most effective 4-oxo compounds and, for comparisons an active 4-amino derivative, were then co-crystallized with the endothelial NOS (NOS-III) oxygenase domain and this structure solved to confirm the hypothetical binding modes. Collectively, these findings suggest (i) that, unlike the antifolate principle, the 4-amino substituent is not essential for developing pterin-based NOS inhibitors and (ii), provide a steric and electrostatic basis for their rational design.
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