TY - JOUR
T1 - Structural basis for pterin antagonism in nitric-oxide synthase
T2 - Development of novel 4-oxo-pteridine antagonists of (6R)-5,6,7,8-tetrahydrobiopterin
AU - Kotsonis, Peter
AU - Fröhlich, Lothar G.
AU - Raman, C. S.
AU - Li, Huiying
AU - Berg, Michael
AU - Gerwig, Rainer
AU - Groehn, Viola
AU - Kang, Yonghan
AU - Al-Masoudi, Najim
AU - Taghavi-Moghadam, Shahriyar
AU - Mohr, Detlev
AU - Münch, Ursula
AU - Schnabel, Joachim
AU - Martásek, Pavel
AU - Masters, Bettie S.S.
AU - Strobel, Hartmut
AU - Poulos, Thomas
AU - Matter, Hans
AU - Pfleiderer, Wolfgang
AU - Schmidt, Harald H.H.W.
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2001/12/28
Y1 - 2001/12/28
N2 - 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 (H4Bip)-binding site of NOS, which, upon cofactor binding, maximally increases enzyme activity and NO production from substrate L-arginine. The first generation of H 4Bip-based NOS inhibitors employed a 4-amino pharmacophore of H 4Bip 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 Phe462 and Ser104, 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.
AB - 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 (H4Bip)-binding site of NOS, which, upon cofactor binding, maximally increases enzyme activity and NO production from substrate L-arginine. The first generation of H 4Bip-based NOS inhibitors employed a 4-amino pharmacophore of H 4Bip 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 Phe462 and Ser104, 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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U2 - 10.1074/jbc.M011469200
DO - 10.1074/jbc.M011469200
M3 - Article
C2 - 11590164
AN - SCOPUS:0242407670
VL - 276
SP - 49133
EP - 49141
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 52
ER -