RESUMO
Dual-specificity protein phosphatases (DUSPs), which dephosphorylate both phosphoserine/threonine and phosphotyrosine, play vital roles in immune activation, brain function and cell-growth signalling. A family-wide structural library of human DUSPs was constructed based on experimental structure determination supplemented with homology modelling. The catalytic domain of each individual DUSP has characteristic features in the active site and in surface-charge distribution, indicating substrate-interaction specificity. The active-site loop-to-strand switch occurs in a subtype-specific manner, indicating that the switch process is necessary for characteristic substrate interactions in the corresponding DUSPs. A comprehensive analysis of the activity-inhibition profile and active-site geometry of DUSPs revealed a novel role of the active-pocket structure in the substrate specificity of DUSPs. A structure-based analysis of redox responses indicated that the additional cysteine residues are important for the protection of enzyme activity. The family-wide structures of DUSPs form a basis for the understanding of phosphorylation-mediated signal transduction and the development of therapeutics.
Assuntos
Fosfatases de Especificidade Dupla/química , Fosfatases de Especificidade Dupla/classificação , Inibidores Enzimáticos/química , Filogenia , Domínio Catalítico , Cristalografia por Raios X , Cisteína/química , Fosfatases de Especificidade Dupla/antagonistas & inibidores , Fosfatases de Especificidade Dupla/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Humanos , Hidrólise , Modelos Moleculares , Oxirredução , Fosfosserina/química , Fosfotreonina/química , Fosfotirosina/química , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/classificação , Proteínas Recombinantes/genética , Transdução de Sinais , Homologia Estrutural de Proteína , Especificidade por SubstratoRESUMO
Recently, dual-specificity phosphatase 16 (DUSP16) emerged as a promising therapeutic target protein for the development of anti-atherosclerosis and anticancer medicines. The present study was undertaken to identify the novel inhibitors of DUSP16 based on the structure-based virtual screening. We have been able to find seven novel inhibitors of DUSP16 through the drug design protocol involving homology modeling of the target protein, docking simulations between DUSP16 and its putative inhibitors with the modified scoring function, and in vitro enzyme assay. These inhibitors revealed good potency, with IC50 values ranging from 1 to 22 µM, and they were also screened computationally for having desirable physicochemical properties as drug candidates. Therefore, they deserve consideration for further development by structure-activity relationship studies to optimize the inhibitory activity against DUSP16. Structural features relevant to the stabilization of the newly identified inhibitors in the active site of DUSP16 are addressed in detail.
Assuntos
Fosfatases de Especificidade Dupla/antagonistas & inibidores , Fosfatases de Especificidade Dupla/química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Fosfatases da Proteína Quinase Ativada por Mitógeno/antagonistas & inibidores , Fosfatases da Proteína Quinase Ativada por Mitógeno/química , Domínio Catalítico , Desenho de Fármacos , Fosfatases de Especificidade Dupla/metabolismo , Inibidores Enzimáticos/metabolismo , Concentração Inibidora 50 , Fosfatases da Proteína Quinase Ativada por Mitógeno/metabolismo , Modelos Moleculares , Simulação de Acoplamento Molecular , Homologia Estrutural de Proteína , Relação Estrutura-Atividade , Interface Usuário-ComputadorRESUMO
Although slingshot phosphatase 1 (SSH1) proved to be a promising target for the development of therapeutics for the treatment of vascular diseases and cancers, no small-molecule inhibitor has been reported so far. We have been able to identify eight novel inhibitors of SSH1 through the computer-aided drug design protocol involving homology modeling of SSH1 structure, virtual screening of a large chemical library with docking simulations, and in vitro enzyme assays. The identified inhibitors revealed high potencies with the associated IC(50) values ranging from 2.8 to 12.7µM and were also screened for having desirable physicochemical properties as a drug candidate. Therefore, they deserve consideration for further development by structure-activity relationship studies to optimize the inhibitory activities. Structural features relevant to the stabilization of the inhibitors in the active site of SSH1 are discussed in detail.
Assuntos
Modelos Moleculares , Fosfoproteínas Fosfatases/química , Algoritmos , Sequência de Aminoácidos , Sítios de Ligação , Desenho de Fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Simulação de Acoplamento Molecular , Dados de Sequência Molecular , Fosfoproteínas Fosfatases/antagonistas & inibidores , Ligação Proteica , Alinhamento de Sequência , Relação Estrutura-AtividadeRESUMO
VH1-like phosphatase Z (VHZ) has proved to be a promising target for the development of therapeutics for the treatment of human cancers. Here, we report the first example for a successful application of structure-based virtual screening to identify the novel small-molecule inhibitors of VHZ. These inhibitors revealed high potencies with the associated IC(50) values ranging from 3 to 20 µM and were also screened for having desirable physicochemical properties as a drug candidate. Therefore, they deserve consideration for further development by structure-activity relationship studies to optimize inhibitory and anticancer activities. Structural features relevant to the stabilization of the newly identified inhibitors in the active site of VHZ are discussed in detail.