RESUMO
(+)-Plakevulin A (1), an oxylipin isolated from an Okinawan sponge Plakortis sp. inhibits enzymatic inhibition of DNA polymerases (pols) α and δ and exhibits cytotoxicity against murine leukemia (L1210) and human cervix carcinoma (KB) cell lines. However, the half-maximal inhibitory concentration (IC50) value for cytotoxicity significantly differed from those observed for the enzymatic inhibition of pols α and ß, indicating the presence of target protein(s) other than pols. This study demonstrated cytotoxicity against human promyelocytic leukemia (HL60), human cervix epithelioid carcinoma (HeLa), mouse calvaria-derived pre-osteoblast (MC3T3-E1), and human normal lung fibroblast (MRC-5) cell lines. This compound had selectivity to cancer cells over normal ones. Among these cell lines, HL60 exhibited the highest sensitivity to (+)-plakevulin A. (+)-Plakevulin A induced DNA fragmentation and caspase-3 activation in HL60 cells, indicating its role in apoptosis induction. Additionally, hydroxysteroid 17-ß dehydrogenase 4 (HSD17B4) was isolated from the HL60 lysate as one of its binding proteins through pull-down experiments using its biotinylated derivative and neutravidin-coated beads. Moreover, (+)-plakevulin A suppressed the activation of interleukin 6 (IL-6)-induced signal transducer and activator of transcription 3 (STAT3). Because the knockdown or inhibition of STAT3 induces apoptosis and HSD17B4 regulates STAT3 activation, (+)-plakevulin A may induce apoptosis in HL60 cell lines by suppressing STAT3 activation, potentially by binding to HSD17B4. The present findings provide valuable information for the mechanism of its action.
Assuntos
Apoptose , Interleucina-6 , Fator de Transcrição STAT3 , Humanos , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT3/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Células HL-60 , Interleucina-6/metabolismo , Animais , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Ensaios de Seleção de Medicamentos Antitumorais , Relação Dose-Resposta a Droga , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
Targeted protein degradation (TPD), employing proteolysis-targeting chimeras (PROTACs) composed of ligands for both a target protein and ubiquitin ligase (E3) to redirect the ubiquitin-proteasome system (UPS) to the target protein, has emerged as a promising strategy in drug discovery. However, despite the vast number of E3 ligases, the repertoire of E3 ligands utilized in PROTACs remains limited. Here, we report the discovery of a small-molecule degron with a phenylpropionic acid skeleton, derived from a known ligand of S-phase kinase-interacting protein 2 (Skp2), an E3 ligase. We used this degron to design PROTACs inducing proteasomal degradation of HaloTag-fused proteins, and identified key structural relationships. Surprisingly, our mechanistic studies excluded the involvement of Skp2, suggesting that this degron recruits other protein(s) within the UPS.
Assuntos
Proteínas Quinases Associadas a Fase S , Bibliotecas de Moléculas Pequenas , Humanos , Proteínas Quinases Associadas a Fase S/metabolismo , Proteínas Quinases Associadas a Fase S/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/síntese química , Proteólise/efeitos dos fármacos , Fenilpropionatos/química , Fenilpropionatos/farmacologia , Relação Estrutura-Atividade , Complexo de Endopeptidases do Proteassoma/metabolismo , Estrutura Molecular , Ligantes , Células HEK293 , DegronsRESUMO
Melanin is produced by melanocytes to protect human skin from harmful ultraviolet radiation. During skin cell renewal, melanin and dead skin cells are disposed of. However, prolonged exposure to ultraviolet rays or aging can disturb this cycle, leading to skin hyperpigmentation due to melanin accumulation. Tyrosinase is a crucial enzyme involved in melanin biosynthesis. Although various compounds, including tyrosine inhibitors, that counteract melanin accumulation have been reported, some, such as hydroquinone, are toxic and can cause vitiligo. Meanwhile, the skin is the largest organ and the outermost layer of the immune system, containing a diverse range of bacteria that produce low-toxicity compounds. In the current study, we aim to identify metabolites produced by skin microbiota that inhibit tyrosinase. Specifically, mushroom tyrosinase served as the study model. Following commensal skin bacteria screening, Corynebacterium tuberculostearicum was found to inhibit tyrosinase activity. The active compound was cyclo(l-Pro-l-Tyr); commercially available cyclo(l-Pro-l-Tyr) also exhibited inhibitory activity. Docking simulations suggested that cyclo(l-Pro-l-Tyr) binds to the substrate-binding site of mushroom tyrosinase, obstructing the substrate pocket and preventing its activity. Hence, cyclo(l-Pro-l-Tyr) might have potential applications as a cosmetic agent and food additive.
Assuntos
Corynebacterium , Monofenol Mono-Oxigenase , Pele , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/metabolismo , Humanos , Pele/microbiologia , Pele/efeitos dos fármacos , Pele/metabolismo , Simulação de Acoplamento Molecular , Agaricales/enzimologia , Inibidores Enzimáticos/farmacologia , Peptídeos Cíclicos/farmacologia , Peptídeos Cíclicos/química , Melaninas/metabolismo , Melaninas/biossínteseRESUMO
3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase is the rate-limiting enzyme in the cholesterol biosynthetic pathway, and competitive inhibitors targeting the catalytic domain of this enzyme, so-called statins, are widely used for the treatment of hyperlipidemia. The membrane domain mediates the sterol-accelerated degradation, a post-translational negative feedback mechanism, and small molecules triggering such degradation have been studied as an alternative therapeutic option. Such strategies are expected to provide benefits over catalytic site inhibitors, as the inhibition leads to transcriptional and post-translational upregulation of the enzyme, necessitating a higher dose of the inhibitors and concomitantly increasing the risk of serious adverse effects, including myopathies. Through our previous study on SR12813, a synthetic small molecule that induces degradation of HMG-CoA reductase, we identified a nitrogen-containing bisphosphonate ester SRP3042 as a highly potent HMG-CoA reductase degrader. Here, we performed a systematic structure-activity relationship study to optimize its activity and physicochemical properties, specifically focusing on the reduction of lipophilicity. Mono-fluorination of tert-butyl groups on the molecules was found to increase the HMG-CoA reductase degradation activity while reducing lipophilicity, suggesting the mono-fluorination of saturated alkyl groups as a useful strategy to balance potency and lipophilicity of the lead compounds.
Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases , Oxirredutases , Animais , Cricetinae , Hidroximetilglutaril-CoA Redutases/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Colesterol/metabolismo , Células CHORESUMO
Juglorubin is a natural dye isolated from the culture of Streptomyces sp. 3094, 815, and GW4184. It has been previously synthesized via the biomimetic dimerization of juglomycin C, a plausible genetic precursor. In this study, the derivatives of juglorubin, 1-O-acetyljuglorubin dimethyl ester and juglorubin dimethyl ester, were found to exhibit antiviral activity against hepatitis C virus (HCV) without exerting any remarkable cytotoxicity against host Huh-7 cells. They also inhibited liver X receptor α activation and lipid droplet accumulation in Huh-7 cells. These findings suggest that 1-O-acetyljuglorubin dimethyl ester and juglorubin dimethyl ester targeted the host factors required for HCV production.
Assuntos
Hepacivirus , Hepatite C , Humanos , Hepacivirus/genética , Linhagem Celular , Ésteres , Replicação Viral , Antivirais/farmacologiaRESUMO
Secondary metabolites in plants influence the health of herbivores such as Japanese rock ptarmigans that feed on the leaves and fruits of alpine plants. Thus, it is important to understand the secondary metabolites of alpine plants and their biological activities for conserving Japanese rock ptarmigans. We isolated C-methylflavone from the leaves of Kalmia procumbens, on which Japanese rock ptarmigans feed. Although its structure was deduced to be 8-demethyleucalyptin by comparing its nuclear magnetic resonance (NMR) data with the reported ones, the possibility that the isolated compound is 6-demethyleucalyptin cannot be ruled out. Thus, both isomers were synthesized. The isolated compound was unambiguously determined to be 8-demethyleucalyptin by comparing its NMR data with those of the synthetic ones. Cytotoxic evaluation of 8- and 6-demethyleucalyptins revealed that only the former showed cytotoxicity against HCT116 and MRC-5 cells. The present study provides not only easy access to 8- and 6-demethyleucalyptins, but also their biological information.
Assuntos
Antineoplásicos , Ericaceae , Folhas de Planta/químicaRESUMO
Epo-C12 is a synthetic derivative of epolactaene, isolated from Penicillium sp. BM 1689-P. Epo-C12 induces apoptosis in human acute lymphoblastoid leukemia BALL-1 cells. In our previous studies, seven proteins that bind to Epo-C12 were identified by a combination of pull-down experiments using biotinylated Epo-C12 (Bio-Epo-C12) and mass spectrometry. In the present study, the effect of Epo-C12 on peroxiredoxin 1 (Prx 1), one of the proteins that binds to Epo-C12, was investigated. Epo-C12 inhibited Prx 1 peroxidase activity. However, it did not suppress its chaperone activity. Binding experiments between Bio-Epo-C12 and point-mutated Prx 1s suggest that Epo-C12 binds to Cys52 and Cys83 in Prx 1. The present study revealed that Prx 1 is one of the target proteins through which Epo-C12 exerts an apoptotic effect in BALL-1 cells.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Peroxirredoxinas/antagonistas & inibidores , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Inibidores Enzimáticos , Compostos de Epóxi/química , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Estrutura Molecular , Mutação , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo , Polienos/químicaRESUMO
Dihydropyriculol is a major secondary metabolite of Pyricularia oryzae. However, the biological activity of dihydropyriculol has not been reported. Here, we showed that dihydropyriculol has inhibitory activity against Streptomyces griseus. Localization analysis of dihydropyriculol revealed that dihydropyriculol could reach to S. griseus under confrontation culture. These results suggest that dihydropyriculol can be used as a chemical weapon against S. griseus.
Assuntos
Antibacterianos/toxicidade , Ascomicetos/metabolismo , Benzaldeídos/toxicidade , Álcoois Graxos/toxicidade , Streptomyces griseus/efeitos dos fármacos , Toxinas Biológicas/toxicidade , Antibacterianos/biossíntese , Antibiose , Ascomicetos/efeitos dos fármacos , Ascomicetos/patogenicidade , Benzaldeídos/metabolismo , Cicloeximida/farmacologia , Álcoois Graxos/metabolismo , Gentamicinas/farmacologia , Higromicina B/farmacologia , Testes de Sensibilidade Microbiana , Metabolismo Secundário/efeitos dos fármacos , Streptomyces griseus/crescimento & desenvolvimento , Toxinas Biológicas/biossínteseRESUMO
Pyricularia oryzae is one of the most devastating plant pathogens in the world. This fungus produces several secondary metabolites including the phytotoxin pyriculols, which are classified into 2 types: aldehyde form (pyriculol and pyriculariol) and alcohol form (dihydropyriculol and dihydropyriculariol). Although interconversion between the aldehyde form and alcohol form has been predicted, and the PYC10 gene for the oxidation of alcohol form to aldehyde is known, the gene responsible for the reduction of aldehyde to alcohol form is unknown. Furthermore, previous studies have predicted that alcohol analogs are biosynthesized via aldehyde analogs. Herein, we demonstrated that an aldo/keto reductase PYC7 is responsible for the reduction of aldehyde to alcohol congeners. The results indicate that aldehyde analogs are biosynthesized via alcohol analogs, contradicting the previous prediction. The results suggest that P. oryzae controls the amount of pyriculol analogs using two oxidoreductases, PYC7 and PYC10, thereby controlling the bioactivity of the phytotoxin.