Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Bioorg Med Chem Lett ; 23(11): 3438-42, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23582272

RESUMO

We identified potent, selective PDE2 inhibitors by optimizing residual PDE2 activity in a series of PDE4 inhibitors, while simultaneously minimizing PDE4 activity. These newly designed PDE2 inhibitors bind to the PDE2 enzyme in a cGMP-like mode in contrast to the cAMP-like binding mode found in PDE4. Structure activity relationship studies coupled with an inhibitor bound crystal structure in the active site of the catalytic domain of PDE2 identified structural features required to minimize PDE4 inhibition while simultaneously maximizing PDE2 inhibition.


Assuntos
Azirinas/química , Nucleotídeo Cíclico Fosfodiesterase do Tipo 2/antagonistas & inibidores , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/química , Di-Hidropiridinas/química , Inibidores da Fosfodiesterase 4/química , Inibidores de Fosfodiesterase/química , Animais , Azirinas/metabolismo , Azirinas/uso terapêutico , Sítios de Ligação , Domínio Catalítico , Cristalografia por Raios X , Nucleotídeo Cíclico Fosfodiesterase do Tipo 2/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Di-Hidropiridinas/metabolismo , Di-Hidropiridinas/uso terapêutico , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Osteoartrite/tratamento farmacológico , Inibidores de Fosfodiesterase/metabolismo , Inibidores de Fosfodiesterase/uso terapêutico , Ligação Proteica , Relação Estrutura-Atividade
2.
Bioorg Med Chem Lett ; 23(11): 3443-7, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23597790

RESUMO

Selective phosphodiesterase 2 (PDE2) inhibitors are shown to have efficacy in a rat model of osteoarthritis (OA) pain. We identified potent, selective PDE2 inhibitors by optimizing residual PDE2 activity in a series of phosphodiesterase 4 (PDE4) inhibitors, while minimizing PDE4 inhibitory activity. These newly designed PDE2 inhibitors bind to the PDE2 enzyme in a cGMP-like binding mode orthogonal to the cAMP-like binding mode found in PDE4. Extensive structure activity relationship studies ultimately led to identification of pyrazolodiazepinone, 22, which was >1000-fold selective for PDE2 over recombinant, full length PDEs 1B, 3A, 3B, 4A, 4B, 4C, 7A, 7B, 8A, 8B, 9, 10 and 11. Compound 22 also retained excellent PDE2 selectivity (241-fold to 419-fold) over the remaining recombinant, full length PDEs, 1A, 4D, 5, and 6. Compound 22 exhibited good pharmacokinetic properties and excellent oral bioavailability (F=78%, rat). In an in vivo rat model of OA pain, compound 22 had significant analgesic activity 1 and 3h after a single, 10 mg/kg, subcutaneous dose.


Assuntos
Azepinas/química , Azirinas/química , Nucleotídeo Cíclico Fosfodiesterase do Tipo 2/antagonistas & inibidores , Di-Hidropiridinas/química , Inibidores de Fosfodiesterase/química , Pirazóis/química , Analgésicos/química , Analgésicos/farmacocinética , Analgésicos/uso terapêutico , Animais , Azepinas/farmacocinética , Azepinas/uso terapêutico , Azirinas/farmacocinética , Azirinas/uso terapêutico , Sítios de Ligação , Domínio Catalítico , Cristalografia por Raios X , Nucleotídeo Cíclico Fosfodiesterase do Tipo 2/metabolismo , Di-Hidropiridinas/farmacocinética , Di-Hidropiridinas/uso terapêutico , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Meia-Vida , Osteoartrite/tratamento farmacológico , Inibidores da Fosfodiesterase 4/química , Inibidores de Fosfodiesterase/farmacocinética , Inibidores de Fosfodiesterase/uso terapêutico , Ligação Proteica , Pirazóis/farmacocinética , Pirazóis/uso terapêutico , Ratos , Relação Estrutura-Atividade
3.
J Struct Biol ; 162(1): 152-69, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18086534

RESUMO

In this article, we describe for the first time the high-resolution crystal structure of a phenylalanine tRNA synthetase from the pathogenic bacterium Staphylococcus haemolyticus. We demonstrate the subtle yet important structural differences between this enzyme and the previously described Thermus thermophilus ortholog. We also explain the structure-activity relationship of several recently reported inhibitors. The native enzyme crystals were of poor quality--they only diffracted X-rays to 3-5A resolution. Therefore, we have executed a rational surface mutagenesis strategy that has yielded crystals of this 2300-amino acid multidomain protein, diffracting to 2A or better. This methodology is discussed and contrasted with the more traditional domain truncation approach.


Assuntos
Proteínas de Bactérias/química , Fenilalanina-tRNA Ligase/química , Staphylococcus haemolyticus/enzimologia , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cristalografia por Raios X/métodos , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Molecular , Mutagênese , Fenilalanina-tRNA Ligase/antagonistas & inibidores , Fenilalanina-tRNA Ligase/metabolismo , Engenharia de Proteínas/métodos , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Staphylococcus haemolyticus/genética
4.
Protein Sci ; 16(12): 2657-66, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18029420

RESUMO

N-Acetylglucosamine-1-phosphate uridyltransferase (GlmU) catalyzes the first step in peptidoglycan biosynthesis in both Gram-positive and Gram-negative bacteria. The products of the GlmU reaction are essential for bacterial survival, making this enzyme an attractive target for antibiotic drug discovery. A series of Haemophilus influenzae GlmU (hiGlmU) structures were determined by X-ray crystallography in order to provide structural and functional insights into GlmU activity and inhibition. The information derived from these structures was combined with biochemical characterization of the K25A, Q76A, D105A, Y103A, V223A, and E224A hiGlmU mutants in order to map these active-site residues to catalytic activity of the enzyme and refine the mechanistic model of the GlmU uridyltransferase reaction. These studies suggest that GlmU activity follows a sequential substrate-binding order that begins with UTP binding noncovalently to the GlmU enzyme. The uridyltransferase active site then remains in an open apo-like conformation until N-acetylglucosamine-1-phosphate (GlcNAc-1-P) binds and induces a conformational change at the GlcNAc-binding subsite. Following the binding of GlcNAc-1-P to the UTP-charged uridyltransferase active site, the non-esterified oxygen of GlcNAc-1-P performs a nucleophilic attack on the alpha-phosphate group of UTP. The new data strongly suggest that the mechanism of phosphotransfer in the uridyltransferase reaction in GlmU is primarily through an associative mechanism with a pentavalent phosphate intermediate and an inversion of stereochemistry. Finally, the structural and biochemical characterization of the uridyltransferase active site and catalytic mechanism described herein provides a basis for the structure-guided design of novel antibacterial agents targeting GlmU activity.


Assuntos
Haemophilus influenzae/enzimologia , Nucleotidiltransferases/química , Nucleotidiltransferases/metabolismo , Acetilglucosamina/análogos & derivados , Acetilglucosamina/química , Acetilglucosamina/metabolismo , Sítios de Ligação , Catálise , Cristalografia por Raios X , Ligantes , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Conformação Proteica , Estrutura Terciária de Proteína , Uridina/química , Uridina/metabolismo , Uridina Trifosfato/metabolismo
5.
Biochemistry ; 45(6): 1712-22, 2006 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-16460018

RESUMO

Acetyl-coA carboxylase (ACC) is a central metabolic enzyme that catalyzes the committed step in fatty acid biosynthesis: biotin-dependent conversion of acetyl-coA to malonyl-coA. The bacterial carboxyltransferase (CT) subunit of ACC is a target for the design of novel therapeutics that combat severe, hospital-acquired infections resistant to the established classes of frontline antimicrobials. Here, we present the structures of the bacterial CT subunits from two prevalent nosocomial pathogens, Staphylococcus aureus and Escherichia coli, at a resolution of 2.0 and 3.0 A, respectively. Both structures reveal a small, independent zinc-binding domain that lacks a complement in the primary sequence or structure of the eukaryotic homologue.


Assuntos
Acetil-CoA Carboxilase/metabolismo , Bactérias/enzimologia , Carboxil e Carbamoil Transferases/metabolismo , Zinco/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Sítios de Ligação , Infecção Hospitalar/enzimologia , Cristalografia por Raios X , Escherichia coli/enzimologia , Células Eucarióticas/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Dobramento de Proteína , Staphylococcus aureus/enzimologia
6.
Nat Struct Mol Biol ; 11(12): 1192-7, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15543157

RESUMO

MEK1 and MEK2 are closely related, dual-specificity tyrosine/threonine protein kinases found in the Ras/Raf/MEK/ERK mitogen-activated protein kinase (MAPK) signaling pathway. Approximately 30% of all human cancers have a constitutively activated MAPK pathway, and constitutive activation of MEK1 results in cellular transformation. Here we present the X-ray structures of human MEK1 and MEK2, each determined as a ternary complex with MgATP and an inhibitor to a resolution of 2.4 A and 3.2 A, respectively. The structures reveal that MEK1 and MEK2 each have a unique inhibitor-binding pocket adjacent to the MgATP-binding site. The presence of the potent inhibitor induces several conformational changes in the unphosphorylated MEK1 and MEK2 enzymes that lock them into a closed but catalytically inactive species. Thus, the structures reported here reveal a novel, noncompetitive mechanism for protein kinase inhibition.


Assuntos
Inibidores Enzimáticos/farmacologia , MAP Quinase Quinase 1/química , MAP Quinase Quinase 1/metabolismo , MAP Quinase Quinase 2/química , MAP Quinase Quinase 2/metabolismo , Sítios de Ligação , Sequência Conservada , Dimerização , Inibidores Enzimáticos/química , Humanos , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 2/antagonistas & inibidores , Modelos Moleculares , Estrutura Molecular , Estrutura Quaternária de Proteína , Homologia Estrutural de Proteína
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA