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1.
Cell Physiol Biochem ; 53(2): 413-428, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31415717

RESUMO

BACKGROUND/AIMS: Amyloid plaques, generated during the progression of Alzheimer's disease, cause major neurological deficits due to substantial cell toxicity and death. The underlying cause of plaque generation stems from cleavage of the amyloid precursor protein (APP) by ß-secretase (BACE1). A resulting amyloid-ß (Aß) fragment forms aggregates to produce the main constituent of a plaque. METHODS: Phage display and biopanning techniques were used to identify a 12-mer peptide that had a natural affinity for the BACE1 enzyme. The peptide was translated from phage DNA and synthetically produced. The peptide, at concentrations of 1nM, 10nM and 100nM, was used to confirm binding by direct assay. Non-specific binding to BACE2, renin and cathepsin D was tested by direct binding assay. A BACE1 activity assay was used to determine the peptide effect on cleavage of an APP substrate. Treatment of SY5Y cells with the peptide was used to determine toxicity and prevention of Aß40 and Aß42 production. RESULTS: After identification and synthetic production, the peptide exhibited a strong affinity for BACE1 at nanomolar concentrations in the direct assay. In case of non-specific binding to homologous BACE2, renin and cathepsin D, the peptide showed minor binding but was nullified when in solution with BACE1. The peptide addition to a BACE1 activity assay was able to significantly reduce the amount of substrate cleavage. SY5Y cells, when treated with the peptide, did not show any detrimental morphological changes while being able to reduce the production of natural Aß40 and Aß42. Even under stressed conditions (H2O2 treatment) where the Aß production was higher, the peptide was still able to significantly reduce the effect of BACE1 while not effecting cell viability. CONCLUSION: The identified peptide exhibited strong binding to BACE1 in vitro and was able to reduce production of Aß, suggesting a favourable BACE1 inhibitor for future refining and characterisation.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Fragmentos de Peptídeos/antagonistas & inibidores , Peptídeos/farmacologia , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Linhagem Celular , Descoberta de Drogas , Inibidores Enzimáticos/metabolismo , Humanos , Fragmentos de Peptídeos/metabolismo , Peptídeos/metabolismo
2.
J Agric Food Chem ; 67(32): 9060-9069, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31339696

RESUMO

Glutathione S-transferases (GSTs) play an active role in the development of drug resistance by numerous cancer cells, including melanoma cells, which is a major cause of chemotherapy failure. As part of our continuous effort to explore why dietary polyphenols bearing the catechol moiety (dietary catechols) show usually anticancer activity, catechol-type diphenylbutadiene (3,4-DHB) was selected as a model of dietary catechols to probe whether they work as pro-oxidative chemosensitizers via GST inhibition in melanoma cells. It was found that, in human melanoma A375 cells, 3,4-DHB is easily converted to its ortho-quinone via copper-containing tyrosinase-mediated two-electron oxidation along with generation of reactive oxygen species (ROS) derived from the oxidation; the resulting ortho-quinone and ROS are responsible for its ability to sensitize the cisplatin-resistant cells by inhibiting GST, followed by induction of apoptosis in an ASK1-JNK/p38 signaling cascade and mitochondria-dependent pathway. This work provides further evidence to support that dietary catechols exhibit antimelanoma activity by virtue of their tyrosinase-dependent pro-oxidative role and gives useful information for designing polyphenol-inspired GST inhibitors and sensitizers in chemotherapy against melanoma.


Assuntos
Antineoplásicos/farmacologia , Butadienos/farmacologia , Catecóis/farmacologia , Inibidores Enzimáticos/farmacologia , Glutationa Transferase/antagonistas & inibidores , Melanoma/enzimologia , Monofenol Mono-Oxigenase/química , Antineoplásicos/química , Antineoplásicos/metabolismo , Apoptose , Butadienos/química , Butadienos/metabolismo , Catecóis/química , Catecóis/metabolismo , Linhagem Celular Tumoral , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Glutationa Transferase/metabolismo , Humanos , Melanoma/metabolismo , Melanoma/fisiopatologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Modelos Químicos , Monofenol Mono-Oxigenase/metabolismo , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
3.
J Agric Food Chem ; 67(31): 8617-8625, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31293160

RESUMO

Inhibiting starch digestion can effectively control postprandial blood sugar level. In this study, the in vitro digestion differences among the mixtures of five polyphenols (i.e., procyanidins [PAs], catechin [CA], tannic acid [TA], rutin [RU], and quercetin [QU]) and starch were analyzed through an in vitro simulation test of starch digestion. The interaction characteristics of these five polyphenols with α-amylase and α-glucosidase were investigated in terms of the inhibition effect, dynamics, fluorescence quenching, and circular dichroism (CD). The results revealed that the rapidly digestible starch (RDS) contents decreased, while the resistant starch (RS) contents increased. All five polyphenols inhibited the α-amylase activity through the noncompetitive approach but inhibited the α-glucosidase activity through the competitive approach. Five polyphenols combined with α-amylase spontaneously by using the hydrophobic effect. The interaction of PAs and QU with α-glucosidase were recognized as van der Waals forces and H bonding, whereas CA and TA interacted with α-glucosidase through the hydrophobic effect. All five polyphenols can cause conformational changes in enzymes.


Assuntos
Extratos Vegetais/química , Polifenóis/química , Amido/química , Animais , Digestão , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Cinética , Modelos Biológicos , Extratos Vegetais/metabolismo , Polifenóis/metabolismo , Amido/metabolismo , Suínos , Leveduras/enzimologia , alfa-Amilases/química , alfa-Amilases/metabolismo , alfa-Glucosidases/química , alfa-Glucosidases/metabolismo
4.
Eur J Med Chem ; 177: 316-337, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31158747

RESUMO

Residues in the histone substrate binding sites that differ between the KDM4 and KDM5 subfamilies were identified. Subsequently, a C8-substituted pyrido[3,4-d]pyrimidin-4(3H)-one series was designed to rationally exploit these residue differences between the histone substrate binding sites in order to improve affinity for the KDM4-subfamily over KDM5-subfamily enzymes. In particular, residues E169 and V313 (KDM4A numbering) were targeted. Additionally, conformational restriction of the flexible pyridopyrimidinone C8-substituent was investigated. These approaches yielded potent and cell-penetrant dual KDM4/5-subfamily inhibitors including 19a (KDM4A and KDM5B Ki = 0.004 and 0.007 µM, respectively). Compound cellular profiling in two orthogonal target engagement assays revealed a significant reduction from biochemical to cell-based activity across multiple analogues; this decrease was shown to be consistent with 2OG competition, and suggests that sub-nanomolar biochemical potency will be required with C8-substituted pyrido[3,4-d]pyrimidin-4(3H)-one compounds to achieve sub-micromolar target inhibition in cells.


Assuntos
Inibidores Enzimáticos/farmacologia , Histona Desmetilases com o Domínio Jumonji/antagonistas & inibidores , Piridinas/farmacologia , Pirimidinonas/farmacologia , Linhagem Celular Tumoral , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Histona Desmetilases com o Domínio Jumonji/química , Histona Desmetilases com o Domínio Jumonji/metabolismo , Estrutura Molecular , Ligação Proteica , Piridinas/síntese química , Piridinas/química , Piridinas/metabolismo , Pirimidinonas/síntese química , Pirimidinonas/química , Pirimidinonas/metabolismo , Relação Estrutura-Atividade
5.
Chem Biodivers ; 16(8): e1900243, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31207061

RESUMO

The new complex compounds [RuLCl(p-cymene)] ⋅ 3H2 O and [NiL2 (H2 O)2 ] ⋅ 3H2 O (L: 1-{4-[(2-hydroxy-3-methoxybenzylidene)amino]phenyl}ethanone) were prepared and characterized using FT-IR, 1 H- and 13 C-NMR, mass spectroscopy, TGA, elemental analysis, X-ray powder diffraction and magnetic moment techniques. Octahedral geometry for new Ni(II) and Ru(II) complexes was proposed. Thermal decomposition confirmed the existence of lattice and coordinated water molecule in the complexes. To determine the antioxidant properties of Schiff base ligand and its Ni(II), Ru(II) metal complexes, FRAP, CUPRAC, ABTS and DPPH methods of antioxidant assays were used. Moreover, enzyme inhibition of complexes was evaluated against carbonic anhydrase I and II isoenzymes (CA I and CA II) and acetylcholinesterase (AChE). For CA I and CA II, the best inhibition enzymes, was the Ni(II) complex with 62.98±18.41, 86.17±23.62 Ki values, whereas this inhibition effect showed ligand with 24.53±2.66 Ki value for the AChE enzyme.


Assuntos
Antioxidantes/química , Complexos de Coordenação/química , Inibidores Enzimáticos/química , Níquel/química , Rutênio/química , Bases de Schiff/química , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Anidrase Carbônica I/antagonistas & inibidores , Anidrase Carbônica I/metabolismo , Anidrase Carbônica II/antagonistas & inibidores , Anidrase Carbônica II/metabolismo , Complexos de Coordenação/farmacologia , Inibidores Enzimáticos/metabolismo , Concentração Inibidora 50 , Espectrofotometria Infravermelho
6.
Food Chem ; 297: 124910, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253292

RESUMO

Polyphenols can inhibit the enzymatic browning in food, but their indistinct synergistic effect and conformational change have limited their applications. In this paper, the mixture of quercetin, cinnamic acid and ferulic acid (Group 11, KI = 0.239 mM) possessed a higher inhibition ability than quercetin (KI = 0.361 mM), which could promote the spontaneous binding process. The final Group 11-tyrosinase complex is more stable, and the hydrophobic effect is the major driving force during the binding process. Moreover, there is not a direct relationship between the destruction of secondary structures and catalytic activity of tyrosinase. The interaction between ferulic acid and tyrosinase could destroy the secondary structures of enzyme but it had little impact on the tyrosinase activity. Molecular docking suggested that three polyphenols from Group 11 have synergistic effect on tyrosinase. This study provides new perspectives about the development of tyrosinase inhibitors in food products.


Assuntos
Inibidores Enzimáticos/química , Monofenol Mono-Oxigenase/antagonistas & inibidores , Polifenóis/química , Sítios de Ligação , Cinamatos/química , Cinamatos/metabolismo , Ácidos Cumáricos/química , Ácidos Cumáricos/metabolismo , Inibidores Enzimáticos/metabolismo , Cinética , Simulação de Acoplamento Molecular , Monofenol Mono-Oxigenase/metabolismo , Estrutura Secundária de Proteína , Termodinâmica
7.
Eur J Med Chem ; 178: 93-107, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31176098

RESUMO

Estrogens are the major female sex steroid hormones, estradiol (E2) being the most potent form in humans. Disturbing the balance between E2 and its weakly active oxidized form estrone (E1) leads to diverse types of estrogen-dependent diseases such as endometriosis or osteoporosis. 17ß-Hydroxysteroid dehydrogenase type 1 (17ß-HSD1) catalyzes the biosynthesis of E2 by reduction of E1 while the type 2 enzyme catalyzes the reverse reaction. Thus, 17ß-HSD1 and 17ß-HSD2 are attractive targets for treatment of estrogen-dependent diseases. Recently, we reported the first proof-of-principle study of a 17ß-HSD2 inhibitor in a bone fracture mouse model, using subcutaneous administration. In the present study, our aim was to improve the in vitro ADME profile of the most potent 17ß-HSD1 and 17ß-HSD2 inhibitors described so far. The optimized compounds show strong and selective inhibition of both the human enzymes and their murine orthologs. In addition, they display good metabolic stability in human liver microsomes (S9 fraction), low in vitro cytotoxicity as well as better aqueous solubility and physicochemical properties compared to the lead compounds. These achievements make the compounds eligible for testing in preclinical in vivo animal model studies on the effects of inhibition of 17ß-HSD1 and 17ß-HSD2.


Assuntos
17-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , Inibidores Enzimáticos/farmacocinética , Estradiol Desidrogenases/antagonistas & inibidores , Fenóis/farmacocinética , Tiofenos/farmacocinética , Animais , Sítios de Ligação , Desenho de Drogas , Estabilidade de Medicamentos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Estradiol Desidrogenases/química , Estradiol Desidrogenases/metabolismo , Células HEK293 , Humanos , Camundongos , Microssomos Hepáticos/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Fenóis/síntese química , Fenóis/química , Fenóis/metabolismo , Ligação Proteica , Solubilidade , Relação Estrutura-Atividade , Tiofenos/síntese química , Tiofenos/química , Tiofenos/metabolismo
8.
Chem Pharm Bull (Tokyo) ; 67(6): 556-565, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31155561

RESUMO

Aldose reductase (AR) is associated with the onset of diabetic complications. Botryllazine A and its analogues were synthesized and evaluated for human AR inhibitory activity. Analogues possessing aromatic bicyclic systems at the C5 position of the central pyrazine ring exhibited superior AR inhibiting activity relative to the parent botryllazine A. In addition, the benzoyl groups at positions C2 and C3 of the pyrazine ring were dispensable for this improved inhibitory activity. Conversely, a benzoyl group-containing phenolic hydroxyl groups-at either position C2 or C3 of the pyrazine ring was essential for attainment of high inhibitory activity approaching that of sorbinil (a highly effective AR inhibitor).


Assuntos
Aldeído Redutase/metabolismo , Inibidores Enzimáticos/síntese química , Pirazinas/química , Aldeído Redutase/antagonistas & inibidores , Sítios de Ligação , Domínio Catalítico , Cristalografia por Raios X , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Humanos , Ligações de Hidrogênio , Concentração Inibidora 50 , Conformação Molecular , Simulação de Acoplamento Molecular , Pirazinas/síntese química , Pirazinas/metabolismo
9.
Eur J Med Chem ; 177: 386-400, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31158752

RESUMO

We explored the approach of using an analog of E-64, a well-known and hydrophilic cysteine cathepsin (CC) inhibitor, as a potent cysteine cathepsin-trapping agent (CCTA) to improve the tumor retention of low-molecular-weight, receptor-targeted radiopharmaceuticals. The synthesized hydrophilic CCTA-incorporated, NTSR1-targeted agents demonstrated a substantial increase in cellular retention upon uptake into the NTRS1-positive HT-29 human colon cancer cell line. Similarly, biodistribution studies using HT-29 xenograft mice revealed a significant and substantial increase in tumor retention for the CCTA-incorporated, NTSR1-targeted agent. The intracellular trapping mechanism of the CCTA-incorporated agents by macromolecular adduct formation was confirmed using multiple in vitro and in vivo techniques. Furthermore, utilization of the more hydrophilic CCTA greatly increased the hydrophilicity of the resulting NTSR1-targeted constructs leading to substantial decreases in most non-target tissues in contrast to our previously reported dipeptidyl acyloxymethyl ketone (AOMK) constructs. This work further confirms that the CCTA trapping approach can make significant improvements in the clinical potential of NTSR1-and other receptor-targeted radiopharmaceuticals.


Assuntos
Catepsinas/antagonistas & inibidores , Inibidores Enzimáticos/metabolismo , Peptídeos/metabolismo , Compostos Radiofarmacêuticos/metabolismo , Receptores de Neurotensina/metabolismo , Animais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Feminino , Células HT29 , Humanos , Interações Hidrofóbicas e Hidrofílicas , Lutécio/química , Camundongos SCID , Neoplasias/diagnóstico , Peptídeos/síntese química , Peptídeos/química , Radioisótopos/química , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/química , Distribuição Tecidual
10.
Cell Mol Life Sci ; 76(15): 2917-2932, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31123777

RESUMO

Protein arginine methyltransferases (PRMTs) catalyze the methyl transfer to the arginine residues of protein substrates and are classified into three major types based on the final form of the methylated arginine. Recent studies have shown a strong correlation between PRMT expression level and the prognosis of cancer patients. Currently, crystal structures of eight PRMT members have been determined. Kinetic and structural studies have shown that all PRMTs share similar, but unique catalytic and substrate recognition mechanism. In this review, we discuss the structural similarities and differences of different PRMT members, focusing on their overall structure, S-adenosyl-L-methionine-binding pocket, substrate arginine recognition and catalytic mechanisms. Since PRMTs are valuable targets for drug discovery, we also rationally classify the known PRMT inhibitors into five classes and discuss their mechanisms of action at the atomic level.


Assuntos
Proteína-Arginina N-Metiltransferases/metabolismo , Arginina/metabolismo , Sítios de Ligação , Domínio Catalítico , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Humanos , Metilação , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/metabolismo , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Especificidade por Substrato
11.
Enzyme Microb Technol ; 127: 1-5, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31088611

RESUMO

A two-step strategy was employed to culture Dunaliella tertiolecta, an oleaginous unicellular green alga, combined by the salt stress and sodium azide intervention, to observe their effects on its lipid accumulation. When the algae cultured at different salt concentrations reached the logarithmic growth phase, sodium azide was added. The results showed that the addition of sodium azide significantly increased the lipid content and had no significant effect on cell biomass. The lipid yield and single cell lipid content under 50 µM sodium azide increased by 10.4% and 21.7%. Under the two-step culture condition, combining of the treatment of 50 µM sodium azide and 2.5 M salt stress, the total lipid productivity and single-cell lipid content were 10% and 70.5% higher than that of the control. It seemed that sodium azide and salinity might have a synergistic effect on the lipid accumulation of D. tertiolecta. It can be concluded that sodium azide is an effective inducer of lipid accumulation in D. tertiolecta, and two-stage cultivation is a feasible way to improve lipid accumulation in microalgae.


Assuntos
Clorofíceas/efeitos dos fármacos , Clorofíceas/metabolismo , Inibidores Enzimáticos/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Estresse Salino , Azida Sódica/metabolismo , Biotecnologia/métodos , Clorofíceas/crescimento & desenvolvimento , Lipídeos/análise
12.
Cell Mol Life Sci ; 76(15): 2967-2985, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31104094

RESUMO

The methylation of proteins is integral to the execution of many important biological functions, including cell signalling and transcriptional regulation. Protein methyltransferases (PMTs) are a large class of enzymes that carry out the addition of methyl marks to a broad range of substrates. PMTs are critical for normal cellular physiology and their dysregulation is frequently observed in human disease. As such, PMTs have emerged as promising therapeutic targets with several inhibitors now in clinical trials for oncology indications. The discovery of chemical inhibitors and antagonists of protein methylation signalling has also profoundly impacted our general understanding of PMT biology and pharmacology. In this review, we present general principles for drugging protein methyltransferases or their downstream effectors containing methyl-binding modules, as well as best-in-class examples of the compounds discovered and their impact both at the bench and in the clinic.


Assuntos
Histona-Lisina N-Metiltransferase/metabolismo , Medicina de Precisão , Regulação Alostérica , Sítios de Ligação , Domínio Catalítico , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/uso terapêutico , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Histona-Lisina N-Metiltransferase/classificação , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Processamento de Proteína Pós-Traducional , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Proteína-Arginina N-Metiltransferases/classificação , Proteína-Arginina N-Metiltransferases/metabolismo
13.
Comput Biol Chem ; 80: 390-397, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31125877

RESUMO

Squalene synthase (SQS) is a potential target for hyperlipidemia treatment. To identify novel chemical scaffolds of SQS inhibitors, we generated 3D-QSAR pharmacophore models using HypoGen. The best quantitative pharmacophore model, Hypo 1, was selected for virtual screening using two chemical databases, Specs and Traditional Chinese Medicine database (TCM). The best-mapped hit compounds were then subjected to filtering by Lipinski's rule of five and docking studies to refine the hits. Finally, five compounds were selected from the top-ranked hit compounds for SQS inhibitory assay in vitro. Three of these compounds could inhibit SQS in vitro, and should be further evaluated pre-clinically as a treatment for hyperlipidemia.


Assuntos
Inibidores Enzimáticos/metabolismo , Farnesil-Difosfato Farnesiltransferase/antagonistas & inibidores , Farnesil-Difosfato Farnesiltransferase/metabolismo , Domínio Catalítico , Conjuntos de Dados como Assunto , Desenho de Drogas , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/química , Farnesil-Difosfato Farnesiltransferase/química , Simulação de Acoplamento Molecular , Estrutura Molecular , Ligação Proteica , Relação Quantitativa Estrutura-Atividade
14.
Curr Top Med Chem ; 19(11): 900-913, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31074368

RESUMO

BACKGROUND: Hepatitis C is a disease that constitutes a serious global health problem, is often asymptomatic and difficult to diagnose and about 60-80% of infected patients develop chronic diseases over time. As there is no vaccine against hepatitis C virus (HCV), developing new cheap treatments is a big challenge. OBJECTIVE: The search for new drugs from natural products has been outstanding in recent years. The aim of this study was to combine structure-based and ligand-based virtual screening (VS) techniques to select potentially active molecules against four HCV target proteins from in-house secondary metabolite dataset (SistematX). MATERIALS AND METHODS: From the ChEMBL database, we selected four sets of 1199, 355, 290 and 237chemical structures with inhibitory activity against different targets of HCV to create random forest models with an accuracy value higher than 82% for cross-validation and test sets. Afterward, a ligandbased virtual screen of the entire 1848 secondary metabolites database stored in SistematX was performed. In addition, a structure-based virtual screening was also performed for the same set of secondary metabolites using molecular docking. RESULTS: Finally, using consensus analyses approach combining ligand-based and structure-based VS, three alkaloids were selected as potential anti-HCV compounds. CONCLUSION: The selected structures are a starting point for further studies in order to develop new anti- HCV compounds based on natural products.


Assuntos
Annonaceae/metabolismo , Antivirais/farmacologia , Apocynaceae/metabolismo , Inibidores Enzimáticos/farmacologia , Hepacivirus/efeitos dos fármacos , Menispermaceae/metabolismo , Antivirais/química , Antivirais/metabolismo , Bases de Dados Factuais , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Hepacivirus/metabolismo , Testes de Sensibilidade Microbiana , Conformação Molecular , Simulação de Acoplamento Molecular
15.
Eur J Med Chem ; 175: 107-113, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31077996

RESUMO

The DNA-repair enzyme MutT homolog 1 (MTH1) is a potential target for a broad range of tumors. Its substrate binding site features a non-catalytical pair of aspartic acids which resembles the catalytic dyad of aspartic proteases. We hypothesized that inhibitors of the latter might be re-targeted for MTH1 despite the two enzyme classes having different substrates and catalyze different reactions. We selected from the crystal structures of holo aspartic proteases a library of nearly 350 inhibitors for in silico screening. Three fragment hits were identified by docking and scoring according to a force field-based energy with continuum dielectric solvation. These fragments showed good ligand efficiency in a colorimetric assay (MW <300 Da and IC50<50µM). Molecular dynamics simulations were carried out for determining the most favorable interaction patterns. On the basis of the simulation results we evaluated in vitro seven commercially available compounds, two of which showed submicromolar potency for MTH1. To obtain definitive evidence of the predicted binding modes we solved the crystal structures of five of the 10 inhibitors predicted in silico. The final step of hit optimization was guided by protein crystallography and involved the synthesis of a single compound, the lead 11, which shows nanomolar affinity for MTH1 in two orthogonal binding assays, and selectivity higher than 2000-fold against its original target (BACE1). The high rate of fragment-hit identification and the fast optimization suggest that ligand retargeting by binding site analogy is an efficient strategy for drug design.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Enzimas Reparadoras do DNA/antagonistas & inibidores , Desenho de Drogas , Inibidores Enzimáticos/farmacologia , Monoéster Fosfórico Hidrolases/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Enzimas Reparadoras do DNA/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Ligantes , Simulação de Acoplamento Molecular , Estrutura Molecular , Monoéster Fosfórico Hidrolases/metabolismo , Reprodutibilidade dos Testes
16.
Eur J Med Chem ; 175: 357-372, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31096156

RESUMO

Lysine-specific demethylase 1 (LSD1), demethylase against mono- and di - methylated histone3 lysine 4, has emerged as a promising target in oncology. More specifically, it has been demonstrated as a key promoter in acute myeloid leukemia (AML), and several LSD1 inhibitors have already entered into clinical trials for the treatment of AML. In this paper, a series of new indole derivatives were designed and synthesized based on a lead compound obtained by a high-throughput screening with our in-house compound library. Among the synthetic compounds, 9e was characterized as a potent LSD1 inhibitor with an IC50 of 1.230 µM and can inhibit the proliferation of THP-1 cells effectively. And most importantly, this is the first irreversible LSD1 inhibitor that is not derived from monoamine oxidase inhibitors. Hence, the discovery of 9e may serve as a proof of concept work for AML treatment.


Assuntos
Descoberta de Drogas , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Histona Desmetilases/antagonistas & inibidores , Indóis/síntese química , Indóis/farmacologia , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Furanos/química , Ensaios de Triagem em Larga Escala , Histona Desmetilases/metabolismo , Humanos , Indóis/química , Indóis/metabolismo , Concentração Inibidora 50 , Leucemia Mieloide Aguda/patologia , Proteínas Recombinantes/efeitos dos fármacos , Proteínas Recombinantes/metabolismo , Relação Estrutura-Atividade
17.
Chem Pharm Bull (Tokyo) ; 67(4): 382-388, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30930442

RESUMO

As an important epigenetics related enzyme, protein arginine methyltransferase 5 (PRMT5) has been confirmed as an anticancer therapeutic target in recent years. Among all the reported PRMT5 inhibitors, two small molecules (GSK-3326595 and JNJ-64619178) are currently being assessed in clinical trial. In this study, 40 PRMT5 inhibitor candidates were purchased from SPECS database supplier according to the pharmacophore and molecular docking based virtual screening results. Alpha linked immunosorbent assay (LISA) methylation assay was performed to test their inhibitory activity against PRMT5. The in vitro enzymatic assay results indicated that four compounds (2, 4, 10 and 37) showed PRMT5 inhibitory activity, while 4 and 10 displayed the most potent activity with IC50 values of 8.1 ± 1.1 and 6.5 ± 0.6 µM, respectively. The inhibitory activity results of 20 extra analogs of 4 further confirmed the potency of this scaffold. As expected, compounds 4 and 10 exhibited moderate anti-proliferative activity against mantle cell lymphoma Jeko-1 and leukemia cell MV4-11. Besides, Western blot assay results showed that 4 could reduce the H4R3me2s level in a dose-dependent manner, indicating that it could inhibit the activity of PRMT5 in cellular context. Detailed interactions between 4 and PRMT5 were characterized by binding mode analysis through molecular docking. The compounds discovered in this study will inspire medicinal chemists to further explore this series of PRMT5 inhibitors.


Assuntos
Descoberta de Drogas , Inibidores Enzimáticos/química , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Pirimidinas/química , Pirróis/química , Quinolinas/química , Sítios de Ligação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Estrutura Terciária de Proteína , Proteína-Arginina N-Metiltransferases/metabolismo , Pirimidinas/metabolismo , Pirimidinas/farmacologia , Pirróis/metabolismo , Pirróis/farmacologia , Quinolinas/metabolismo , Quinolinas/farmacologia , Relação Estrutura-Atividade
18.
Chem Biodivers ; 16(6): e1900032, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30957403

RESUMO

The inhibition of carbohydrate-hydrolyzing enzymes in human digestive organs is crucial in controlling blood sugar levels, which is important in treating type 2 diabetes. In the current study, pahangensin A (1), a bis-labdanic diterpene characterized previously in the rhizomes of Alpinia pahangensis Ridl., was identified as an active dual inhibitor for α-amylase (IC50 =114.80 µm) and α-glucosidase (IC50 =153.87 µm). This is the first report on the dual α-amylase and α-glucosidase inhibitory activities of a bis-labdanic diterpene. The Lineweaver-Burk plots of compound 1 indicate that it is a mixed-type inhibitor with regard to both enzymes. Based on molecular docking studies, compound 1 docked in a non-active site of both enzymes. The dual inhibitory activity of compound 1 makes it a suitable natural alternative in the treatment of type 2 diabetes.


Assuntos
Alpinia/química , Diterpenos/química , alfa-Amilases/metabolismo , alfa-Glucosidases/metabolismo , Alpinia/metabolismo , Sítios de Ligação , Domínio Catalítico , Diterpenos/isolamento & purificação , Diterpenos/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Cinética , Simulação de Acoplamento Molecular , Extratos Vegetais/química , alfa-Amilases/antagonistas & inibidores , alfa-Glucosidases/química
19.
Comput Biol Chem ; 80: 102-110, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30947068

RESUMO

Glyoxalase system is an ubiquitous system in human cells which has been examined thoroughly for its role in different diseases. It comprises two enzymes; Glyoxalase I (Glo-I) and Glyoxalase II (Glo-II) which perform detoxifying endogenous harmful metabolites, mainly methylglyoxal (MG) into non-toxic bystanders. In silico computer Aided Drug Design approaches were used and ninety two diverse pharmacophore models were generated from eighteen Glyoxalase I crystallographic complexes. Subsequent QSAR modeling followed by ROC evaluation identified a single pharmacophore model which was able to predict the expected Glyoxalase I inhibition. Screening of the National Cancer Institute (NCI) database using the optimal pharmacophore Hypo(3VW9) identified several promising hits. Thirty eight hits were successfully predicted then ordered and evaluated in vitro. Seven hits out of the thirty eight tested compounds showed more than 50% inhibition with low micromolar IC50.


Assuntos
Antineoplásicos/metabolismo , Inibidores Enzimáticos/metabolismo , Lactoilglutationa Liase/antagonistas & inibidores , Lactoilglutationa Liase/metabolismo , Antineoplásicos/química , Domínio Catalítico , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/química , Humanos , Lactoilglutationa Liase/química , Simulação de Acoplamento Molecular , Estrutura Molecular , Ligação Proteica , Relação Quantitativa Estrutura-Atividade , Curva ROC , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/metabolismo , Sulfonamidas/química , Sulfonamidas/metabolismo
20.
Chem Biodivers ; 16(6): e1900065, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31012543

RESUMO

11ß-Hydroxysteroid dehydrogenase type 1 (11ß-HSD1) is an enzyme that affects the body's cortisol levels. The inhibition of its activity can be used in the treatment of Cushing's syndrome, metabolic syndrome and type 2 diabetes. In this study, we synthesized new derivatives of 2-(methylamino)thiazol-4(5H)-one and tested their activity towards inhibition of 11ß-HSD1 and its isoform - 11ß-HSD2. The results were compared with the previously tested allyl derivatives. We found out that methyl derivatives are weaker inhibitors of 11ß-HSD1 in comparison to their allyl analogs. Due to significant differences in the activity of the compounds, molecular modeling was performed, which was aimed at comparing the interactions between 11ß-HSD1 and ligands differing by substituent at the amine group (allyl vs. methyl). Modeling showed that the absence of the allyl group can lead to the rotation of whole ligand molecule which affects its interaction with the enzyme.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Inibidores Enzimáticos/síntese química , Tiazóis/química , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/antagonistas & inibidores , Sítios de Ligação , Inibidores Enzimáticos/metabolismo , Humanos , Ligantes , Simulação de Acoplamento Molecular , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Estrutura Terciária de Proteína , Relação Estrutura-Atividade , Tiazóis/metabolismo
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