RESUMO
Ligand-based Virtual Screening (VS) methods aim at identifying molecules with a similar activity profile across phenotypic and macromolecular targets to that of a query molecule used as search template. VS using 3D similarity methods have the advantage of biasing this search toward active molecules with innovative chemical scaffolds, which are highly sought after in drug design to provide novel leads with improved properties over the query molecule (e.g. patentable, of lower toxicity or increased potency). Ultrafast Shape Recognition (USR) has demonstrated excellent performance in the discovery of molecules with previously-unknown phenotypic or target activity, with retrospective studies suggesting that its pharmacophoric extension (USRCAT) should obtain even better hit rates once it is used prospectively. Here we present USR-VS (http://usr.marseille.inserm.fr/), the first web server using these two validated ligand-based 3D methods for large-scale prospective VS. In about 2 s, 93.9 million 3D conformers, expanded from 23.1 million purchasable molecules, are screened and the 100 most similar molecules among them in terms of 3D shape and pharmacophoric properties are shown. USR-VS functionality also provides interactive visualization of the similarity of the query molecule against the hit molecules as well as vendor information to purchase selected hits in order to be experimentally tested.
Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Internet , Preparações Farmacêuticas/análise , Preparações Farmacêuticas/química , Software , Desenho de Fármacos , Fluspirileno/química , Indóis/química , Ligantes , Reprodutibilidade dos Testes , Sulfonamidas/química , VemurafenibRESUMO
The inhibition of tumor suppressor p53 protein due to its direct interaction with oncogenic murine double minute 2 (MDM2) protein, plays a central role in almost 50 % of all human tumor cells. Therefore, pharmacological inhibition of the p53-binding pocket on MDM2, leading to p53 activation, presents an important therapeutic target against these cancers expressing wild-type p53. In this context, the present study utilized an integrated virtual and experimental screening approach to screen a database of approved drugs for potential p53-MDM2 interaction inhibitors. Specifically, using an ensemble rigid-receptor docking approach with four MDM2 protein crystal structures, six drug molecules were identified as possible p53-MDM2 inhibitors. These drug molecules were then subjected to further molecular modeling investigation through flexible-receptor docking followed by Prime/MM-GBSA binding energy analysis. These studies identified fluspirilene, an approved antipsychotic drug, as a top hit with MDM2 binding mode and energy similar to that of a native MDM2 crystal ligand. The molecular dynamics simulations suggested stable binding of fluspirilene to the p53-binding pocket on MDM2 protein. The experimental testing of fluspirilene showed significant growth inhibition of human colon tumor cells in a p53-dependent manner. Fluspirilene also inhibited growth of several other human tumor cell lines in the NCI60 cell line panel. Taken together, these computational and experimental data suggest a potentially novel role of fluspirilene in inhibiting the p53-MDM2 interaction. It is noteworthy here that fluspirilene has a long history of safe human use, thus presenting immediate clinical potential as a cancer therapeutic. Furthermore, fluspirilene could also serve as a structurally-novel lead molecule for the development of more potent, small-molecule p53-MDM2 inhibitors against several types of cancer. Importantly, the combined computational and experimental screening protocol presented in this study may also prove useful for screening other commercially-available compound databases for identification of novel, small molecule p53-MDM2 inhibitors.
Assuntos
Neoplasias do Colo/tratamento farmacológico , Fluspirileno/química , Proteínas Proto-Oncogênicas c-mdm2/química , Proteína Supressora de Tumor p53/química , Animais , Neoplasias do Colo/patologia , Cristalografia por Raios X , Fluspirileno/uso terapêutico , Humanos , Camundongos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Proteínas Proto-Oncogênicas c-mdm2/antagonistas & inibidores , Proteína Supressora de Tumor p53/antagonistas & inibidoresRESUMO
The X-ray crystal structures of four butyrophenone analogues have been completed and are reported herein. These include spiperone hydrochloride (I), N-methylspiperone hydrochloride (II), pimozide (III), and fluspirilene (IV). These structures were compared to other structurally similar molecules with similar pharmacological activity. In addition, a molecular modeling study was done in order to determine the low energy conformations of these molecules. It was found that calculations of parameters that describe the molecular conformations showed that all four molecules were structurally similar. Crystallographic data: [see text]
Assuntos
Cristalografia/métodos , Fluspirileno/química , Modelos Moleculares , Pimozida/química , Espiperona/análogos & derivados , Butirofenonas/química , Estrutura Molecular , Espiperona/químicaRESUMO
Partition coefficients, Kp, of four dopamine antagonists (pimozide, fluspirilene, haloperidol and domperidone) between the aqueous phase and lipid bilayer vesicles were determined as a function of lipid chain length, unsaturation and temperature encompassing the range of the lipid phase transition. Model membranes of egg phosphatidylcholine (PC), dimyristoyl (DMPC)-, dipalmitoyl (DPPC)-, distearoyl (DSPC)- and dioleoyl (DOPC)-phosphatidylcholines were studied. Kp values of the drugs are different in the various membranes under study and depend on temperature, aliphatic carbon chain-length and on the presence of unsaturation in the aliphatic lipid chain. First-order transition of membrane lipids from the gel to the liquid crystalline state is accompanied by a sharp increase of the partition coefficient of pimozide and fluspirilene in DMPC, DPPC and DSPC bilayers. For domperidone, Kp values are maximal within the mid-point of phase transition of DMPC and DPPC, while for DSPC Kp values increase progressively with increasing temperature. Haloperidol Kp values display a maximum at the mid-point of phase transition of DMPC, while a progressive increase of Kp is observed in DPPC and DSPC. The four drugs are easily accommodated in bilayers of short aliphatic chain lipids (DMPC), the partition coefficients being 17,137 for pimozide, 18,700 for fluspirilene, 686 for domperidone and 722 for haloperidol, at temperatures 10 degrees C below the mid-point of the lipid phase transition. Except for haloperidol, the partition of the drugs in DOPC (18:1) is higher than that in DSPC (18:0) bilayers at a temperature above the phase transition temperature of both lipids.(ABSTRACT TRUNCATED AT 250 WORDS)