Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 81.299
Filtrar
1.
Chem Biol Interact ; 318: 108973, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-32035862

RESUMO

Carbon monoxide (CO) is an inorganic chemical compound that can bind with hemoglobin with highly toxic effects. In living organisms, it is produced endogenously during the degradation of heme by oxygenase, which occurs in three isoforms: HO-1, HO-2 and HO-3. CO can play an important role in the regulation of many physiological functions. Carbon Oxide Releasing Molecules (CORMs) are a novel group of chemical compounds capable of controlled CO release directly in tissues or organs. This release depends on concentration, pH, solvent type and temperature. The biological role and the therapeutic potential of different CORMs is not always well demonstrated. However, this mini review summarizes the various function of these compounds.


Assuntos
Monóxido de Carbono/química , Monóxido de Carbono/metabolismo , Animais , Monóxido de Carbono/toxicidade , Heme/química , Heme/metabolismo , Heme Oxigenase (Desciclizante)/metabolismo , Isoenzimas
2.
J Enzyme Inhib Med Chem ; 35(1): 489-497, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31914827

RESUMO

A series of amino acid-sulphonamide conjugates was prepared through benzotriazole mediated coupling reactions and characterised by 1H-NMR, 13C-NMR, MS, and FTIR spectroscopic techniques as well as elemental analysis. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory activity of the new compounds was determined against four human (h) isoforms, hCA I, hCA II, hCA VA, and hCA XII. Most of the synthesised compounds showed effective in vitro CA inhibitory properties. The new amino acid-sulphonamide conjugates showed potent inhibitory activity against hCA II, some of them at subnanomolar levels, exhibiting more effective inhibitory activity compared to the standard drug acetazolamide. Some of these sulphonamides were also found to be effective inhibitors of hCA I, hCA VA, and hCA XII, with activity from the low to high nanomolar range.


Assuntos
Aminoácidos/farmacologia , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Sulfonamidas/farmacologia , Aminoácidos/síntese química , Aminoácidos/química , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Estrutura Molecular , Sulfonamidas/síntese química , Sulfonamidas/química
3.
J Enzyme Inhib Med Chem ; 35(1): 506-510, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31928252

RESUMO

The hypothesis that sulfocoumarin acting as inhibitors of human carbonic anhydrase (CA, EC 4.2.1.1) cancer-associated isoforms hCA IX and - hCA XII is being able to also inhibit thioredoxin reductase was verified and confirmed. The dual targeting of two cancer cell defence mechanisms, i.e. hypoxia and oxidative stress, may both contribute to the observed antiproliferative profile of these compounds against many cancer cell lines. This unprecedented dual anticancer mechanism may lead to a new approach for designing innovative therapeutic agents.


Assuntos
Antineoplásicos/farmacologia , Anidrase Carbônica IX/antagonistas & inibidores , Anidrases Carbônicas/metabolismo , Cumarínicos/farmacologia , Inibidores Enzimáticos/farmacologia , Tiorredoxina Dissulfeto Redutase/antagonistas & inibidores , Antígenos de Neoplasias/metabolismo , Antineoplásicos/síntese química , Antineoplásicos/química , Anidrase Carbônica IX/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cumarínicos/síntese química , Cumarínicos/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Células MCF-7 , Estrutura Molecular , Relação Estrutura-Atividade , Tiorredoxina Dissulfeto Redutase/metabolismo , Células Tumorais Cultivadas
4.
Toxicol Lett ; 322: 131-139, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31953209

RESUMO

Cyanotoxins, among which >200 variants of Microcystins (MC), constitute an emerging issue in food safety. Microcystins (MC) toxicity is congener-specific; however, the in vitro inhibition of PP1/PP2A (the key molecular event of MC toxicity) by single MC variants is comparable and MC toxicokinetics seems to be the critical point. Here, the variability in GSH conjugation catalysed by human recombinant enzymes and human hepatic cytosol has been compared between hydrophilic (MC-LR and MC-RR) and hydrophobic (MC-LW, MC-YR and MC-LF) variants, according to measured logPow. In vitro detoxication reaction (spontaneous plus enzymatic) is favored by the variant hydrophilicity, with MC-LF very poorly detoxified. With MC-YR and -LW the spontaneous reaction always gave the major contribution, whereas with MC-LR and -RR the enzymatic reaction became by far predominant when GSH was depleted. Consequently, the well-known GST polymorphisms seems not to be the major driver for potential human variability in susceptibility towards the MC-toxicity, except for MC-RR and -LR when GSH is depleted. Looking at these results and literature data, MC-RR (the least cytotoxic and acutely toxic in rodents) is the more hydrophilic, has the lowest OATP-mediated hepatic uptake and the highest detoxication efficiency. The opposite is true for the most lipophilic MC-LF: once entered in the cells with the highest uptake, it is very poorly detoxified, and resulted as the most toxic in various cell types. MC-dependent TK should be considered in order to estimate the variability in toxicity and to support the use of quantitative in vitro-in vivo extrapolation models of single toxins and their mixtures co-occurring in the environment.


Assuntos
Glutationa Transferase/metabolismo , Fígado/enzimologia , Microcistinas/metabolismo , Relação Dose-Resposta a Droga , Feminino , Glutationa/metabolismo , Glutationa Transferase/genética , Humanos , Interações Hidrofóbicas e Hidrofílicas , Inativação Metabólica , Isoenzimas , Masculino , Microcistinas/química , Microcistinas/toxicidade , Estrutura Molecular , Polimorfismo Genético , Proteínas Recombinantes/metabolismo , Medição de Risco , Especificidade por Substrato , Toxicocinética
5.
Toxicol Lett ; 319: 148-154, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31707106

RESUMO

In vitro cytochrome P450 inhibition of major kratom alkaloids: mitragynine (MTG), speciogynine (SPG), speciocilliatine (SPC), corynantheidine (COR), 7-hydroxymitragynine (7HMG) and paynantheine (PAY) was evaluated using human liver microsomes (HLMs) to understand their drug-drug interaction potential. CYP450 isoform-specific substrates of CYP1A2, 2C8, 2C9, 2C19, 2D6, and 3A4/5 were incubated in HLMs with or without alkaloids. Preliminary CYP450 inhibition (IC50) data were generated for each of these isoforms. In addition, the type of inhibition and estimation of the inhibition constants (Ki) of MTG and COR were determined. Among the tested alkaloids, MTG and COR were potent inhibitors of CYP2D6 (IC50, 2.2 and 4.2 µM, respectively). Both MTG and COR exhibited competitive inhibition of CYP2D6 activity and the Ki were found to be 1.1 and 2.8 µM, respectively. SPG and PAY showed moderate inhibition of CYP2D6 activity. Additionally, moderate inhibitory effects by SPC, MTG, and SPG were observed on CYP2C19 activity. Interestingly, inhibition of only midazolam hydroxylase CYP3A4/5 activity by COR, PAY, and MTG was observed while no inhibitory effect was observed when testosterone was used as a probe substrate. In conclusion, MTG and COR may lead to clinically significant adverse drug interactions upon coadministration of drugs that are substantially metabolized by CYP2D6.


Assuntos
Alcaloides/farmacologia , Inibidores das Enzimas do Citocromo P-450/farmacologia , Interações de Medicamentos , Mitragyna/química , Sistema Enzimático do Citocromo P-450/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Humanos , Isoenzimas/efeitos dos fármacos , Isoenzimas/metabolismo , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo
6.
Eur J Med Chem ; 186: 111896, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31784185

RESUMO

We report here a thorough structure-activity relationship (SAR) with piperazinylureido sulfamates as inhibitors of human (h) carbonic anhydrase (CA, EC 4.2.1.1). A SAR investigation over the structure of reported anti-cancer zinc-binder CAIs such as SLC-0111 and S4 was carried out by including the urea outer nitrogen atom into a substituted piperazine ring reducing the linker flexibility. The derivatives were assessed for the inhibition of CA I, II and IV (off-target isoforms) and the tumor-associated CA IX (anticancer drug target). CA I and IV were not effectively inhibited, whereas many low nanomolar inhibitors were evidenced against CA II (KIs in the range of 1.0-705.5 nM), and IX (KIs in the range of 0.91-155.9 nM). Interestingly, a subset of CA II/IX selective inhibitors was detected which might represent interesting lead for the development of new anticancer strategies.


Assuntos
Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Piperazinas/farmacologia , Sulfonamidas/farmacologia , Ácidos Sulfônicos/farmacologia , Ureia/farmacologia , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Relação Dose-Resposta a Droga , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Piperazinas/química , Relação Estrutura-Atividade , Sulfonamidas/química , Ácidos Sulfônicos/química , Ureia/análogos & derivados , Ureia/química
7.
Eur J Med Chem ; 186: 111906, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31787362

RESUMO

Protein disulfide isomerase (PDI, PDIA1) is an emerging therapeutic target in oncology. PDI inhibitors have demonstrated a unique propensity to selectively induce apoptosis in cancer cells and overcome resistance to existing therapies, although drug candidates have not yet progressed to the stage of clinical development. We recently reported the discovery of lead indene compound E64FC26 as a potent pan-PDI inhibitor that enhances the cytotoxic effects of proteasome inhibitors in panels of Multiple Myeloma (MM) cells and MM mouse models. An extensive medicinal chemistry program has led to the generation of a diverse library of indene-containing molecules with varying degrees of proteasome inhibitor potentiating activity. These compounds were generated by a novel nucleophilic aromatic ring cyclization and dehydration reaction from the precursor ketones. The results provide detailed structure activity relationships (SAR) around this indene pharmacophore and show a high degree of correlation between potency of PDI inhibition and bortezomib (Btz) potentiation in MM cells. Inhibition of PDI leads to ER and oxidative stress characterized by the accumulation of misfolded poly-ubiquitinated proteins and the induction of UPR biomarkers ATF4, CHOP, and Nrf2. This work characterizes the synthesis and SAR of a new chemical class and further validates PDI as a therapeutic target in MM as a single agent and in combination with proteasome inhibitors.


Assuntos
Bortezomib/farmacologia , Pró-Colágeno-Prolina Dioxigenase/antagonistas & inibidores , Inibidores de Proteassoma/farmacologia , Isomerases de Dissulfetos de Proteínas/antagonistas & inibidores , Bortezomib/síntese química , Bortezomib/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Estrutura Molecular , Pró-Colágeno-Prolina Dioxigenase/metabolismo , Inibidores de Proteassoma/síntese química , Inibidores de Proteassoma/química , Isomerases de Dissulfetos de Proteínas/metabolismo , Relação Estrutura-Atividade
8.
J Enzyme Inhib Med Chem ; 35(1): 365-371, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31854205

RESUMO

The selectivity for a specific human Carbonic Anhydrase (hCA) isoform is an important property a hCA inhibitor (CAI) should be endowed with, in order to constitute a valuable therapeutic tool for the treatment of a desired pathology. In this context, we developed a chemoinformatic platform that allows the analysis of the structure and selectivity profile of known CAIs reported in literature, with the aim of identifying structural motifs connected to ligand selectivity, thus providing useful guidelines for the design of novel ligands selective for the desired hCA isoform. The platform is able to perform ultrafast structure and selectivity analyses through ligand fingerprint similarity, with no need of structural information about the target receptor and ligands' binding mode. It is easily accessible to the non-expert user through the implementation of a KNIME Analytic Platform workflow and could be extended to analyze the selectivity profile of known ligands of different target proteins.


Assuntos
Inibidores da Anidrase Carbônica/análise , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Análise por Conglomerados , Relação Dose-Resposta a Droga , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Ligantes , Estrutura Molecular , Relação Estrutura-Atividade
9.
Eur J Med Chem ; 187: 111962, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31887569

RESUMO

The aldehyde dehydrogenases (ALDHs) are a family of detoxifying enzymes that are overexpressed in various cancers. Increased expression of ALDH is associated with poor prognosis, stemness, and drug resistance. Because of the critical role of ALDH in cancer stem cells, several ALDH inhibitors have been developed. Nonetheless, all these inhibitors either lack efficacy or are too toxic or have not been tested extensively. Thus, the continued development of ALDH inhibitors is warranted. In this study, we designed and synthesized potent multi-ALDH isoform inhibitors based on the isatin backbone. The early molecular docking studies and enzymatic tests revealed that 3(a-l) and 4(a-l) are the potent ALDH1A1, ALDHA2, and ALDH3A1 inhibitors. ALDH inhibitory IC50s of 3(a-l) and 4(a-l) were 230 nM to >10,000 nM for ALDH1A1, 939 nM to >10,000 nM for ALDH2 and 193 nM to >10,000 nM for ALDH3A1. The most potent compounds 3(h-l) had IC50s for killing melanoma cells ranged from 2.1 to 5.7 µM, while for colon cancer cells, it ranged from 2.5 to 5.8 µM and for multiple myeloma cells ranging from 0.3 to 4.7 µM. Toxicity studies of 3(h-l) revealed that 3h to be the least toxic multi-ALDH isoform inhibitor. Mechanistically, 3(h-l) caused increased ROS activity, lipid peroxidation, and toxic aldehyde accumulation, secondary to potent multi-ALDH isoform inhibition leading to increased apoptosis and G2/M cell cycle arrest. Together, the study details the design, synthesis, and evaluation of potent, multi-isoform ALDH inhibitors to treat cancers.


Assuntos
Aldeído Desidrogenase/antagonistas & inibidores , Antineoplásicos/farmacologia , Desenho de Drogas , Inibidores de Proteínas Quinases/farmacologia , Aldeído Desidrogenase/metabolismo , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Camundongos , Simulação de Acoplamento Molecular , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Relação Estrutura-Atividade
10.
Eur J Med Chem ; 185: 111843, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31718943

RESUMO

In the presented work, we report the design and synthesis of different new sets of triazolopyrimidine-based (9a-d) and triazole-based (11a-h, 13a-c, 15a,b, 17a,b and 21a-g) benzenesulfonamides. The newly synthesized sulfonamides were assessed for their inhibitory activities toward four human (h) metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1) isoforms; hCA I, II, IX and XII. The four examined isoforms were inhibited by the prepared sulfonamides (9a-d, 11a-h, 13a-c, 15a,b, 17a,b and 21a-g) in variable degrees with KIs ranges: 94.4-4953.5 nM for hCA I, 6.9-837.6 nM for hCA II, 3.3-85.0 nM for hCA XI, and 4.4-105.0 nM for hCA XII. In particular, sulfonamides 11e, 21a and 21e emerged as single-digit nanomolar hCA IX and hCA XII inhibitors. Interestingly, triazolopyrimidine-based sulfonamide 9d and triazole-based sulfonamide 21e were found to be the most selective hCA IX inhibitors over hCA I (SI = 100.85 and 210.58, respectively) and hCA II (SI = 18.54 and 38.36, respectively). Thereafter, sulfonamides 9d and 21e were docked into the active site of CAs II, IX and XII, then poses showing the best scoring values and favorable binding interactions were subjected to a MM-GBSA based refinement and, limited to CA IX and XII, to a cycle of 100 ns molecular dynamics.


Assuntos
Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Simulação de Dinâmica Molecular , Pirimidinas/farmacologia , Sulfonamidas/farmacologia , Triazóis/farmacologia , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Relação Dose-Resposta a Droga , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Estrutura Molecular , Pirimidinas/química , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/química , Triazóis/química
11.
Eur J Med Chem ; 185: 111825, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31740053

RESUMO

By applying an approach of a "ring with two tails", a series of novel inhibitors possessing high-affinity and significant selectivity towards selected carbonic anhydrase (CA) isoforms has been designed. The "ring" consists of 2-chloro/bromo-benzenesulfonamide, where the sulfonamide group is as an anchor coordinating the Zn(II) in the active site of CAs, and halogen atom orients the ring affecting the affinity and selectivity. First "tail" is a substituent containing carbonyl, carboxyl, hydroxyl, ether groups or hydrophilic amide linkage. The second "tail" contains aryl- or alkyl-substituents attached through a sulfanyl or sulfonyl group. Both "tails" are connected to the benzene ring and play a crucial role in selectivity. Varying the substituents, we designed compounds selective for CA VII, CA IX, CA XII, or CA XIV. Since due to binding-linked protonation reactions the binding-ready fractions of the compound and protein are much lower than one, the "intrinsic" affinities were calculated that should be used to study correlations between crystal structures and the thermodynamics of binding for rational drug design. The "intrinsic" affinities together with the intrinsic enthalpies and entropies of binding together with co-crystal structures were used demonstrate structural factors determining major contributions for compound affinity and selectivity.


Assuntos
Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Sulfonamidas/farmacologia , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Halogenação , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/química
12.
Biochim Biophys Acta Bioenerg ; 1861(1): 148089, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31669487

RESUMO

Leaves of Arabidopsis thaliana plants grown in short days (8 h light) generate more reactive oxygen species in the light than leaves of plants grown in long days (16 h light). The importance of the two PsaE isoforms of photosystem I, PsaE1 and PsaE2, for O2 reduction was studied in plants grown under these different growth regimes. In short day conditions a mutant affected in the amount of PsaE1 (psae1-1) reduced more efficiently O2 than a mutant lacking PsaE2 (psae2-1) as shown by spin trapping EPR spectroscopy on leaves and by following the kinetics of P700+ reduction in isolated photosystem I. In short day conditions higher O2 reduction protected photosystem II against photoinhibition in psae1-1. In contrast in long day conditions the presence of PsaE1 was clearly beneficial for photosynthetic electron transport and for the stability of the photosynthetic apparatus under photoinhibitory conditions. We conclude that the two PsaE isoforms have distinct functions and we propose that O2 reduction at photosystem I is beneficial for the plant under certain environmental conditions.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Oxigênio/metabolismo , Fotossíntese/fisiologia , Complexo de Proteína do Fotossistema I/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Transporte de Elétrons/fisiologia , Isoenzimas/genética , Isoenzimas/metabolismo , Oxirredução , Complexo de Proteína do Fotossistema I/genética
13.
J Enzyme Inhib Med Chem ; 35(1): 245-254, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31790605

RESUMO

A new series of homosulfocoumarins (3H-1,2-benzoxathiepine 2,2-dioxides) possessing various substitution patterns and moieties in the 7, 8 or 9 position of the heterocylic ring were prepared by original procedures and investigated for the inhibition of four physiologically relevant carbonic anhydrase (CA, EC 4.2.1.1) isoforms, the human (h) hCA I, II, IX and XII. The 8-substituted homosulfocoumarins were the most effective hCA IX/XII inhibitors followed by the 7-substituted derivatives, whereas the substitution pattern in position 9 led to less effective binders for the transmembrane, tumour-associated isoforms IX/XII. The cytosolic isoforms hCA I and II were not inhibited by these compounds, similar to the sulfocoumarins/coumarins investigated earlier. As hCA IX and XII are validated anti-tumour targets, with one sulphonamide (SLC-0111) in Phase Ib/II clinical trials, finding derivatives with better selectivity for inhibiting the tumour-associated isoforms over the cytosolic ones, as the homosulfocoumarins reported here, is of crucial importance.


Assuntos
Benzotiepinas/farmacologia , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Benzotiepinas/síntese química , Benzotiepinas/química , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Relação Dose-Resposta a Droga , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Estrutura Molecular , Relação Estrutura-Atividade
14.
Food Chem ; 305: 125440, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31494496

RESUMO

Tea (Camellia sinensis) contains two active glutamate decarboxylases (CsGADs), whose unclear properties were examined here. CsGAD1 was 4-fold higher than CsGAD2 in activity. Their Km values for L-glutamate were around 5 mM. CsGAD1 and CsGAD2 performed best at 55 and 40 °C, respectively, and were both stimulated by calcium/calmodulin (Ca2+/CaM). Over 40 °C, their calmodulin-binding domains degraded. CsGADs were most active at pH 5.6, and were stimulated by Ca2+/CaM at pH 5.6-6.6, but inactivated at pH 3.6. Ca2+/CaM restored the CsGAD1 activity suppressed by inhibitors. CsGADs and CsCaM were localized to the cytosol. CsGAD1 was more highly expressed in most tissues, while CsGAD2 expression was more induced under stresses. The characteristics we first elucidated here revealed that CsGAD1 is the predominant isoform in tea plant, with CsGAD2 exhibiting a supplementary role under certain conditions. The information will contribute to regulation of GABA tea quality.


Assuntos
Camellia sinensis/enzimologia , Glutamato Descarboxilase/metabolismo , Proteínas de Plantas/metabolismo , Ácido gama-Aminobutírico/metabolismo , Secas , Estabilidade Enzimática , Ácido Glutâmico/metabolismo , Concentração de Íons de Hidrogênio , Isoenzimas/metabolismo , Cinética , Temperatura Ambiente
15.
Adv Exp Med Biol ; 1131: 215-242, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31646512

RESUMO

Phospholipase C (PLC) family members constitute a family of diverse enzymes. Thirteen different family members have been cloned. These family members have unique structures that mediate various functions. Although PLC family members all appear to signal through the bi-products of cleaving phospholipids, it is clear that each family member, and at times each isoform, contributes to unique cellular functions. This chapter provides a review of the current literature on PLC. In addition, references have been provided for more in-depth information regarding areas that are not discussed including tyrosine kinase activation of PLC. Understanding the roles of the individual PLC enzymes, and their distinct cellular functions, will lead to a better understanding of the physiological roles of these enzymes in the development of diseases and the maintenance of homeostasis.


Assuntos
Fosfolipases Tipo C , Fenômenos Fisiológicos Celulares , Humanos , Isoenzimas , Fosfolipases Tipo C/metabolismo
16.
Eur J Med Chem ; 187: 111952, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31846828

RESUMO

Cyclin-dependent kinase (CDK) family members are promising molecular targets in discovering potent inhibitors in disease settings, they function differentially. CDK2, CDK4 and CDK6, directly regulate the cell cycle, while CDK9 primarily modulates the transcription regulation. In discovering inhibitors of these CDKs, toxicity associated with off-target effect on other CDK homologs often posts as a clinical issue and hinders their further therapeutic development. To improve efficacy and reduce toxicity, here, using the Proteolysis Targeted Chimeras (PROTACs) approach, we design and further optimize small molecule degraders targeting multiple CDKs. We showed that heterobifunctional compound A9 selectively degraded CDK2. We also identified a dual-degrader, compound F3, which potently induced degradation of both CDK2 (DC50: 62 nM) and CDK9 (DC50: 33 nM). In human prostate cancer PC-3 cells, compound F3 potently inhibits cell proliferation by effectively blocking the cell cycle in S and G2/M phases. Our preliminary data suggests that PROTAC-oriented CDK2/9 degradation is potentially an effective therapeutic approach.


Assuntos
Quinases Ciclina-Dependentes/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Proteólise/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Quinases Ciclina-Dependentes/metabolismo , Relação Dose-Resposta a Droga , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Células MCF-7 , Modelos Moleculares , Estrutura Molecular , Células PC-3 , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Relação Estrutura-Atividade , Células Tumorais Cultivadas
17.
Pol J Vet Sci ; 22(4): 789-792, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31867924

RESUMO

We measured the bone-specific alkaline phosphatase (ALP) isoenzyme activity in 67 plasma samples from 14 newborn Holstein calves using both a conventional method (featuring heat inactivation) and a commercial agarose gel electrophoresis (AGE) kit; the relevant isoenzymes were termed bone-specific ALP (BAP) and ALP isoenzyme 3 (ALP3). We explored whether the AGE kit afforded reliable data when used to analyze samples from Holstein calves. The blood was collected from the jugular vein of each calf immediately prior to the first colostrum feeding (pre-feeding), 20 and 40 h after pre-feeding, and on days 4 and 7; whereas three samples (from three calves) were not obtained. The total plasma ALP activity varied widely, exceeding the ranges of reference values. On electrophoresis, 52 of 67 plasma samples (77.6 %) clearly contained both ALP isoenzyme 2 and ALP3, as did control human serum. The total ALP activity of the 52 samples ranged from 166-1989 U/L (median: 1013 U/L), whereas the values for the other 15 samples (22.4%) exhibiting abnormal isoenzyme fractionation ranged from 1014-5118 U/L (median: 1780 U/L). In the 52 plasma samples exhibiting clearly separated isoenzymes, ALP3 and BAP activities were strongly positively correlated as revealed by Deming regression (y = 0.93x + 22.6, p⟨0.0001) and Bland-Altman analysis (ALP3/BAP activities limit of agreement: -5.1%). Thus, the AGE kit yields useful information on newborn calves, and can replace the conventional method when the total plasma ALP activity is less than approximately 1000 U/L.


Assuntos
Fosfatase Alcalina/sangue , Osso e Ossos/enzimologia , Bovinos/sangue , Eletroforese em Gel de Ágar/veterinária , Fosfatase Alcalina/metabolismo , Animais , Animais Recém-Nascidos , Isoenzimas/sangue , Kit de Reagentes para Diagnóstico
18.
Nat Cell Biol ; 21(11): 1436-1448, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31685992

RESUMO

PTENα and PTENß are two longer translational variants of phosphatase and tensin homolog (PTEN) messenger RNA. Their expressional regulations and functions in carcinogenesis remain largely unknown. Here, we demonstrate that, in contrast with the well-established tumour-suppressive role of canonical PTEN, PTENα and PTENß promote tumourigenesis by directly interacting with the histone H3 lysine 4 (H3K4) presenter WDR5 to promote H3K4 trimethylation and maintain a tumour-promoting signature. We also show that USP9X and FBXW11 bind to the amino-terminal extensions of PTENα/ß, and respectively deubiquitinate and ubiquitinate lysines 235 and 239 in PTENα to regulate PTENα/ß stability. In accordance, USP9X promotes tumourigenesis and FBXW11 suppresses tumourigenesis through PTENα/ß. Taken together, our results indicate that the Pten gene is a double-edged sword for carcinogenesis, and reinterpretation of the importance of the Pten gene in carcinogenesis is warranted.


Assuntos
Carcinogênese/genética , Carcinoma Hepatocelular/genética , Regulação Neoplásica da Expressão Gênica , Histonas/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Hepáticas/genética , PTEN Fosfo-Hidrolase/genética , Animais , Carcinogênese/metabolismo , Carcinogênese/patologia , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Feminino , Histonas/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Isoenzimas/genética , Isoenzimas/metabolismo , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Camundongos Nus , PTEN Fosfo-Hidrolase/metabolismo , Proteólise , Transdução de Sinais , Análise de Sobrevida , Ubiquitina Tiolesterase/genética , Ubiquitina Tiolesterase/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas Contendo Repetições de beta-Transducina/genética , Proteínas Contendo Repetições de beta-Transducina/metabolismo
19.
Adv Neurobiol ; 23: 125-145, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31667807

RESUMO

Glycogen constitutes the main store of glucose in animal cells. Being present at much lower concentrations in the brain than in liver and muscles, brain glycogen has long been considered as an emergency source of glucose, mobilized under stress conditions (including hypoglyceamia). Nevertheless, over the past decade, multiple studies have shed a new light on the roles of brain glycogen, being notably an energy supply critical for high-cognitive processes such as learning and memory consolidation. Glycogen phosphorylase (GP) is the key enzyme regulating the mobilization of glycogen in cells. It is found in humans as three isozymes: muscle (mGP), liver (lGP) and brain GP (bGP). In the brain, astrocytes express both mGP and bGP while neurons only express the brain isoform. Although GP isozymes are very similar, their distinct regulatory features confer them distinct metabolic functions that are strongly related to the roles of glycogen in different tissues. Here, we provide an overview of the functions, the regulations and the structures of GPs in the brain and their relation to the specific roles of glycogen in astrocytes and neurons. We also discuss novel findings concerning the specific regulations of bGP by oxidative stress, and the potential of these enzymes as therapeutic targets in the brain.


Assuntos
Encéfalo/enzimologia , Glicogênio Fosforilase/química , Glicogênio Fosforilase/metabolismo , Glicogênio , Animais , Encéfalo/metabolismo , Glicogênio/metabolismo , Humanos , Isoenzimas/química , Isoenzimas/metabolismo , Fígado/enzimologia , Fígado/metabolismo , Músculos/enzimologia , Músculos/metabolismo
20.
Biochem Soc Trans ; 47(5): 1247-1257, 2019 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-31671180

RESUMO

P-type ATPases transport ions across biological membranes against concentration gradients and are essential for all cells. They use the energy from ATP hydrolysis to propel large intramolecular movements, which drive vectorial transport of ions. Tight coordination of the motions of the pump is required to couple the two spatially distant processes of ion binding and ATP hydrolysis. Here, we review our current understanding of the structural dynamics of P-type ATPases, focusing primarily on Ca2+ pumps. We integrate different types of information that report on structural dynamics, primarily time-resolved fluorescence experiments including single-molecule Förster resonance energy transfer and molecular dynamics simulations, and interpret them in the framework provided by the numerous crystal structures of sarco/endoplasmic reticulum Ca2+-ATPase. We discuss the challenges in characterizing the dynamics of membrane pumps, and the likely impact of new technologies on the field.


Assuntos
Bombas de Íon/química , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/química , Trifosfato de Adenosina/metabolismo , Animais , Cálcio/metabolismo , Catálise , Humanos , Hidrólise , Bombas de Íon/metabolismo , Isoenzimas/química , Isoenzimas/metabolismo , Fosforilação , Ligação Proteica , Conformação Proteica , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA