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1.
Acta Virol ; 63(3): 278-285, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31507193

RESUMO

Dengue virus (DENV) infection is one of the most widely-spread flavivirus infections with no effective antiviral drugs available. Peptide inhibitors have been considered as one of the best drug candidates due to their high specificity, selectivity in their interactions and minimum side effects. In this study, we employed computational studies using YASARA, HADDOCK server and PyMOL software to generate short and linear peptides based on a reference peptide, CP5-46A, to block DENV NS2B-NS3 protease. The inhibition potencies of the peptides were evaluated using in-house DENV2 serine protease and fluorogenic peptide substrates. In vitro analyses were performed to determine the peptides cytotoxicity and the inhibitory effects against DENV2 replication in WRL-68 cells. Our computational analyses revealed that the docking energy of AYA3, a 16 amino acid (aa) (-81.2 ± 10.6 kcal/mol) and AYA9, a 15 aa peptide (-83.8 ± 6.8 kcal/mol) to DENV NS2B-NS3 protease were much lower than the reference peptide (46 aa; -70.9 ± 7.8 kcal/mol) and the standard protease inhibitor, aprotinin (58 aa; -48.2 ± 10.6 kcal/mol). Both peptides showed significant inhibition against DENV2 NS2B-NS3 protease activity with IC50 values of 24 µM and 23 µM, respectively. AYA3 and AYA9 peptides also demonstrated approximately 68% and 83% of viral plaque reduction without significantly affecting cell viability at 50 µM concentration. In short, we generated short linear peptides with lower cytotoxic effect and substantial antiviral activities against DENV2. Further studies are required to investigate the inhibitory effects of these peptides in vivo. Keywords: peptide inhibitors; dengue virus; NS2B-NS3 protease; plaque reduction.


Assuntos
Antivirais , Vírus da Dengue , Peptídeos , Inibidores de Proteases , Replicação Viral , Antivirais/farmacologia , Biologia Computacional , Vírus da Dengue/enzimologia , Ativação Enzimática/efeitos dos fármacos , Humanos , Peptídeos/síntese química , Peptídeos/farmacologia , Inibidores de Proteases/farmacologia , Replicação Viral/efeitos dos fármacos
2.
An Acad Bras Cienc ; 91(2): e20180248, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31269103

RESUMO

The phenolic extracts of jabuticaba skin flour (JSF) were characterized by HPLC, and evaluated for their modulating action upon phospholipases A2 and proteases of snake venom, aiming at their possible use in the treatment of the various diseases associated with the action of venom toxins. Two types of extracts were prepared from JSF: aqueous and methanolic. These extracts, evaluated at different ratios, (venom: extract, m/m), significantly inhibited the phospholipase activity induced by the venom of Bothrops moojeni and Crotalus durissus terrificus, except for Bothrops atrox venom. The greatest hemolysis inhibitory action was observed for the methanolic extract, when incubated with venoms of B. moojeni and C. durissus terrificus, with inhibitions between 21 and 100%. Thrombolysis induced by venoms of B. moojeni and C. durissus terrificus was inhibited by both extracts, ranging from 32 to 83% and 51 to 83% for the aqueous and methanolic extracts, respectively. Both extracts extended coagulation time, induced by the venoms of B. moojeni and Lachesis muta muta. Inhibitory actions are related to phenolic compounds, such as gallic, syringic and p-coumaric acids, besides catechin, epigallocatechin gallate, epicatechin; resveratrol and quercetin, present in the extracts of jabuticaba skin flour, confirming their potential for nutraceutical use.


Assuntos
Myrtaceae/química , Inibidores de Fosfolipase A2/farmacologia , Extratos Vegetais/farmacologia , Inibidores de Proteases/farmacologia , Venenos de Víboras/antagonistas & inibidores , Animais , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Humanos , Inibidores de Fosfolipase A2/isolamento & purificação , Inibidores de Proteases/isolamento & purificação , Venenos de Víboras/enzimologia
3.
Cancer Immunol Immunother ; 68(8): 1245-1261, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31222486

RESUMO

The efficacy of cancer immunotherapy, including treatment with immune-checkpoint inhibitors, often is limited by ineffective presentation of antigenic peptides that elicit T-cell-mediated anti-tumor cytotoxic responses. Manipulation of antigen presentation pathways is an emerging approach for enhancing the immunogenicity of tumors in immunotherapy settings. ER aminopeptidase 1 (ERAP1) is an intracellular enzyme that trims peptides as part of the system that generates peptides for binding to MHC class I molecules (MHC-I). We hypothesized that pharmacological inhibition of ERAP1 in cells could regulate the cellular immunopeptidome. To test this hypothesis, we treated A375 melanoma cells with a recently developed potent ERAP1 inhibitor and analyzed the presented MHC-I peptide repertoire by isolating MHC-I, eluting bound peptides, and identifying them using capillary chromatography and tandem mass spectrometry (LC-MS/MS). Although the inhibitor did not reduce cell-surface MHC-I expression, it induced qualitative and quantitative changes in the presented peptidomes. Specifically, inhibitor treatment altered presentation of about half of the total 3204 identified peptides, including about one third of the peptides predicted to bind tightly to MHC-I. Inhibitor treatment altered the length distribution of eluted peptides without change in the basic binding motifs. Surprisingly, inhibitor treatment enhanced the average predicted MHC-I binding affinity, by reducing presentation of sub-optimal long peptides and increasing presentation of many high-affinity 9-12mers, suggesting that baseline ERAP1 activity in this cell line is destructive for many potential epitopes. Our results suggest that chemical inhibition of ERAP1 may be a viable approach for manipulating the immunopeptidome of cancer.


Assuntos
Aminopeptidases/metabolismo , Antígenos de Neoplasias/metabolismo , Antineoplásicos/farmacologia , Vacinas Anticâncer/imunologia , Epitopos de Linfócito T/metabolismo , Imunoterapia/métodos , Melanoma/tratamento farmacológico , Antígenos de Histocompatibilidade Menor/metabolismo , Peptídeos/metabolismo , Inibidores de Proteases/farmacologia , Linfócitos T Citotóxicos/imunologia , Aminopeptidases/antagonistas & inibidores , Apresentação do Antígeno , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Antígenos HLA/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Imunogenicidade da Vacina , Ativação Linfocitária , Terapia de Alvo Molecular , Peptídeos/genética , Peptídeos/imunologia , Ligação Proteica
4.
Phys Chem Chem Phys ; 21(27): 14945-14956, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31236554

RESUMO

Zika virus (ZIKV) infection has become a global public health problem, associated with microcephaly in newborns and Guillain-Barré syndrome in adults. Currently, there are no commercially available anti-ZIKV drugs. The viral protease NS2B/NS3, which is involved in viral replication and maturation, is a potential drug target. Peptidomimetic aldehyde inhibitors bind covalently to the catalytic S135 of the NS3 protease. Here, we apply hybrid quantum mechanics/molecular mechanics (QM/MM) free-energy simulations at the PDDG-PM3/ff14SB level to investigate the inhibition mechanism of the ZIKV protease by a dipeptidyl aldehyde inhibitor (acyl-KR-aldehyde). The results show that proton transfer from the catalytic S135 to H51 occurs in concert with nucleophilic addition on the aldehyde warhead by S135. The anionic covalent complex between the dipeptidyl aldehyde and the ZIKV protease is analogous to the tetrahedral intermediate for substrate hydrolysis. Spontaneous protonation by H51 forms the hemiacetal. In addition, we use correlated ab initio QM/MM potential energy path calculations at levels up to LCCSD(T)/(aug)-cc-pVTZ to obtain accurate potential energy profiles of the reaction, which also support a concerted mechanism. These results provide detailed insight into the mechanism of ZIKV protease inhibition by a peptidyl aldehyde inhibitor, which will guide in the design of inhibitors.


Assuntos
Aldeídos/farmacologia , Serina Proteases/metabolismo , Zika virus/enzimologia , Aldeídos/química , Dipeptídeos/química , Dipeptídeos/farmacologia , Desenho de Drogas , Transferência de Energia , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , Teoria Quântica
5.
Nat Commun ; 10(1): 2430, 2019 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-31160583

RESUMO

Muscle loss due to fibrotic or adipogenic replacement of myofibers is common in muscle diseases and muscle-resident fibro/adipogenic precursors (FAPs) are implicated in this process. While FAP-mediated muscle fibrosis is widely studied in muscle diseases, the role of FAPs in adipogenic muscle loss is not well understood. Adipogenic muscle loss is a feature of limb girdle muscular dystrophy 2B (LGMD2B) - a disease caused by mutations in dysferlin. Here we show that FAPs cause the adipogenic loss of dysferlin deficient muscle. Progressive accumulation of Annexin A2 (AnxA2) in the myofiber matrix causes FAP differentiation into adipocytes. Lack of AnxA2 prevents FAP adipogenesis, protecting against adipogenic loss of dysferlinopathic muscle while exogenous AnxA2 enhances muscle loss. Pharmacological inhibition of FAP adipogenesis arrests adipogenic replacement and degeneration of dysferlin-deficient muscle. These results demonstrate the pathogenic role of FAPs in LGMD2B and establish these cells as therapeutic targets to ameliorate muscle loss in patients.


Assuntos
Tecido Adiposo/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , Distrofia Muscular do Cíngulo dos Membros/metabolismo , Células-Tronco/citologia , Adipócitos/patologia , Adipogenia/efeitos dos fármacos , Tecido Adiposo/patologia , Adolescente , Idade de Início , Animais , Anexina A2/metabolismo , Estudos de Casos e Controles , Disferlina/genética , Venenos Elapídicos/toxicidade , Feminino , Fibrose , Humanos , Técnicas In Vitro , Masculino , Camundongos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/patologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Distrofia Muscular do Cíngulo dos Membros/genética , Distrofia Muscular do Cíngulo dos Membros/patologia , Fenilalanina/análogos & derivados , Fenilalanina/farmacologia , Inibidores de Proteases/farmacologia , Índice de Gravidade de Doença , Células-Tronco/efeitos dos fármacos , Tiofenos/farmacologia , Adulto Jovem
6.
J Appl Microbiol ; 127(3): 670-682, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31165532

RESUMO

AIMS: Experiments were designed to determine the effects of different chemical inhibitors of lysozyme and peptidases on rumen protozoa and the associated prokaryotes, and in vitro fermentation using Entodinium caudatum as a model protozoan species. METHODS AND RESULTS: Imidazole (a lysozyme inhibitor), phenylmethylsulphonyl fluoride (PMSF, a serine peptidase inhibitor) and iodoacetamide (IOD, a cysteine peptidase inhibitor) were evaluated in vitro both individually and in two- and three-way combinations using E. caudatum monocultures with respect to their ability to inhibit the protozoan and their effect on feed digestion, fermentation and the microbiota. All the three inhibitors, both individually and in combination, decreased E. caudatum counts (P < 0·001), and IOD and its combinations with the other inhibitors significantly (P < 0·01) decreased ammonia concentration, with the two- and three-way combinations showing additive effective. Feed digestion was not affected, but fermentation and microbial diversity were affected mostly by PMSF, IOD and their combinatorial treatments potentially due to the overgrowth of Streptococcus luteciae accompanying with the disappearance of host ciliates. CONCLUSIONS: Entodinium caudatum depends on lysozyme and peptidase for digestion and utilization of the engulfed microbes and specific inhibition of these enzymes can inhibition E. caudatum without adversely affecting feed digestion or fermentation even though they changed the microbiota composition in the cultures. SIGNIFICANCE AND IMPACT OF THE STUDY: The peptidase inhibitors may have the potential to be used in controlling rumen protozoa to improve ruminal nitrogen utilization efficiency.


Assuntos
Cilióforos/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Muramidase/antagonistas & inibidores , Inibidores de Proteases/farmacologia , Amônia/metabolismo , Animais , Cilióforos/enzimologia , Cilióforos/crescimento & desenvolvimento , Cilióforos/microbiologia , Digestão/efeitos dos fármacos , Fermentação/efeitos dos fármacos , Imidazóis/farmacologia , Iodoacetamida/farmacologia , Microbiota/efeitos dos fármacos , Fluoreto de Fenilmetilsulfonil/farmacologia , Rúmen/parasitologia
7.
J Cancer Res Clin Oncol ; 145(8): 1999-2012, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31172267

RESUMO

BACKGROUND: The processes of prostate cancer (PCa) invasion and metastasis are facilitated by proteolytic cascade involving multiple proteases, such as matrix metalloproteinases, serine proteases and cysteine proteases including cathepsin K (CatK). CatK is predominantly secreted by osteoclasts and specifically degrades collagen I leading to bone destruction. PCa and breast cancer preferentially metastasize to the bone. Importantly, CatK expression level is greater in PCa bone metastatic sites compared to primary tumor and normal prostate tissues. However, the underlying mechanism of CatK during PCa metastases into the bone remains to be elucidated. We investigated the functional role of CatK during the PCa establishment and growth process in the murine bone. METHODS: CatK mRNA expression was validated by RT-PCR, protein expression by immunoblotting in PCa LNCaP, C4-2B, and PC3 cells as well as in PCa tissues. Its protein production was measured using ELISA assay. The effect of both knockdowns via siRNA and CatK inhibitor was compared in regard to PCa cell invasion. We further studied the dose-dependent CatK inhibitor effect on conditioned media-induced bone resorption. In setting up an animal model, C4-2B cells were injected into the tibiae of SCID mice. The animals treated with either vehicle or CatK inhibitor for 8 weeks at the time of tumor cell injection (tumor establishment model; protocol I) or 4 weeks after tumor cell injection (tumor progression model; protocol II) were applied to histological and histomorphometric analyses. RESULTS: We confirmed CatK expression in PCa LNCaP, C4-2B, and PC3 cells as well as in PCa tissues. Furthermore, we observed the inhibitory effects of a selective CatK inhibitor on PCa cell invasion. The CatK inhibitor dose-dependently inhibited PCa-conditioned media-induced bone resorption. Upon injection of C4-2B cells into the tibiae of SCID mice, the selective CatK inhibitor significantly prevented the tumor establishment in protocol I, and reduced the tumor growth in bone in protocol II. It also decreased serum PSA levels in both animal models. The inhibitory effects of the CatK inhibitor were enhanced in combination with zoledronic acid (ZA). CONCLUSION: The selective CatK inhibitor may prevent the establishment and progression of PCa in bone, thus making it a novel therapeutic approach for advanced PCa.


Assuntos
Neoplasias Ósseas/prevenção & controle , Neoplasias Ósseas/secundário , Catepsina K/antagonistas & inibidores , Terapia de Alvo Molecular/métodos , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Inibidores de Proteases/uso terapêutico , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Adenocarcinoma/patologia , Animais , Neoplasias Ósseas/genética , Catepsina K/genética , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Humanos , Masculino , Camundongos , Camundongos SCID , Células PC-3 , Neoplasias da Próstata/genética , Inibidores de Proteases/farmacologia , RNA Interferente Pequeno/farmacologia , RNA Interferente Pequeno/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Lett Appl Microbiol ; 69(2): 88-95, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31102470

RESUMO

Natural enzyme inhibitors have been widely described in literature because of its pharmacological and cosmetic applications. Fungi found in caves represent a promising source of bioactive substances that are still little explored scientifically. Thus, the present work evaluated the presence of enzymatic modulators in a filtrate obtained from the cultivation of the cave fungus Lecanicillium aphanocladii (Family: Cordycipitaceae). Snake venoms from Bothrops alternatus and Bothrops atrox were used as an enzymatic source for the induction of the phospholipase, proteolytic, thrombolytic, cytotoxic and coagulant activities. Compounds present in the fungal filtrate inhibited 50, 23·8, 26·6, 50·9 and 52·5% of the proteolytic, phospholipase, haemolytic, thrombolytic and coagulant activities respectively. The filtrate was not cytotoxic on erythrocytes, but induced partial dissolution of thrombi. Fungal enzyme inhibitors that have low or no toxicity and can be obtained on a large scale and at low cost are relevant in the medical-scientific context. Therefore, the inhibition of phospholipases A2 and proteases observed in the present work highlights the potential of fungal metabolites for the development of drugs that can be used in the treatment of haemostasis and inflammation-related disorders. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, secondary metabolites synthesized by Lecanicillium aphanocladii, a fungus isolated from caves, demonstrated modulating action on proteases and phospholipases A2 present in snake venoms of the Bothrops genus, widely used as tools for the study of pathophysiology processes related to haemostasis and inflammation. The results suggest the possibility of future applications for these metabolites in the development of pharmaceuticals of medical-scientific interest.


Assuntos
Ascomicetos/química , Bothrops/metabolismo , Venenos de Crotalídeos/enzimologia , Peptídeo Hidrolases/metabolismo , Inibidores de Fosfolipase A2/farmacologia , Fosfolipases A2/metabolismo , Inibidores de Proteases/farmacologia , Animais , Ascomicetos/metabolismo , Coagulação Sanguínea/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Hemostasia/efeitos dos fármacos , Humanos , Inflamação/tratamento farmacológico , Proteólise/efeitos dos fármacos
10.
Acta Crystallogr F Struct Biol Commun ; 75(Pt 5): 385-391, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31045568

RESUMO

The inhibition of kallikrein 5 (KLK5) has been identified as a potential strategy for treatment of the genetic skin disorder Netherton syndrome, in which loss-of-function mutations in the SPINK5 gene lead to down-regulation of the endogenous inhibitor LEKTI-1 and profound skin-barrier defects with severe allergic manifestations. To aid in the development of a medicine for this target, an X-ray crystallographic system was developed to facilitate fragment-guided chemistry and knowledge-based drug-discovery approaches. Here, the development of a surrogate crystallographic system in place of KLK5, which proved to be challenging to crystallize, is described. The biochemical robustness of the crystallographic surrogate and the suitability of the system for the study of small nonpeptidic fragments and lead-like molecules are demonstrated.


Assuntos
Benzamidinas/química , Calicreínas/química , Inibidores de Proteases/química , Sequência de Aminoácidos , Animais , Baculoviridae/genética , Baculoviridae/metabolismo , Benzamidinas/farmacologia , Sítios de Ligação , Clonagem Molecular , Cristalografia por Raios X , Descoberta de Drogas , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Humanos , Calicreínas/antagonistas & inibidores , Calicreínas/genética , Calicreínas/metabolismo , Cinética , Modelos Moleculares , Mutação , Síndrome de Netherton/tratamento farmacológico , Síndrome de Netherton/enzimologia , Inibidores de Proteases/farmacologia , Ligação Proteica , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Células Sf9 , Spodoptera , Eletricidade Estática , Especificidade por Substrato
11.
Chem Biol Interact ; 307: 105-115, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31054283

RESUMO

Neutral endopeptidase (NEP) is an enzyme implicated in development of different tumors, e.g. colorectal cancer (CRC). In this study, the anti-cancer effects of NEP inhibitors, thiorphan (synthetic compound) and sialorphin (naturally occurring pentapeptide) on CRC cells were investigated. Moreover, we synthesized some derivatives of sialorphin (alanine scan analogues: AHNPR, QANPR, QHAPR, QHNAR; N-acetylated sialorphin; C-amidated sialorphin, and C-amidated alanine scan analogues) to examine the biological activity of these inhibitors on CRC cells. The cytotoxic activity of the NEP inhibitors against CRC cell lines (SW620 and LS180) and normal human fibroblasts (HSF) was evaluated. Additionally, the influence of NEP inhibitors on proliferation, cell cycle progression, induction of apoptosis, and the level of phosphorylation of MAP kinases and mTORC1 signaling pathway proteins in CRC cells were examined. The NEP inhibitors were non-cytotoxic to HSF cells; however, most of them slightly decreased the viability and inhibited proliferation of CRC cells. The N-acetylation or C-amidation of sialorphin or its alanine scan analogues resulted in decreased or abolished anti-proliferative activity of the NEP inhibitors towards the CRC cells. Additionally, thiorphan and sialorphin enhanced the anti-proliferative activity of other CRC-cell growth inhibitors (atrial natriuretic peptide-ANP and melphalan-MEL). The mechanisms involved in the anti-proliferative effects of the tested inhibitors were mediated via NEP and associated with induction of cell cycle arrest in the G0/G1 phase, increased activity of ERK1/2, and a reduced level of phosphorylation of mTOR (Ser2448), 4E-BP1, and p70S6K. However, the NEP inhibitors did not induce apoptosis in the CRC cells. These results have indicated that thiorphan and sialorphin or its derivatives AHNPR, QANPR, QHAPR, and QHNAR have the potential to be used as agents in treatment of patients with CRC.


Assuntos
Proliferação de Células/efeitos dos fármacos , Endopeptidases/metabolismo , Peptídeos/farmacologia , Inibidores de Proteases/farmacologia , Tiorfano/farmacologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Endopeptidases/química , Endopeptidases/genética , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Humanos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Peptídeos/síntese química , Peptídeos/química , Fosfoproteínas/metabolismo , Fosforilação/efeitos dos fármacos , Inibidores de Proteases/química , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Tiorfano/química
12.
PLoS Pathog ; 15(4): e1007701, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30934020

RESUMO

Knowledge of the within-host frequencies of resistance-associated amino acid variants (RAVs) is important to the identification of optimal drug combinations for the treatment of hepatitis C virus (HCV) infection. Multiple RAVs may exist in infected individuals, often below detection limits, at any resistance locus, defining the diversity of accessible resistance pathways. We developed a multiscale mathematical model to estimate the pre-treatment frequencies of the entire spectrum of mutants at chosen loci. Using a codon-level description of amino acids, we performed stochastic simulations of intracellular dynamics with every possible nucleotide variant as the infecting strain and estimated the relative infectivity of each variant and the resulting distribution of variants produced. We employed these quantities in a deterministic multi-strain model of extracellular dynamics and estimated mutant frequencies. Our predictions captured database frequencies of the RAV R155K, resistant to NS3/4A protease inhibitors, presenting a successful test of our formalism. We found that mutational pathway maps, interconnecting all viable mutants, and strong founder effects determined the mutant spectrum. The spectra were vastly different for HCV genotypes 1a and 1b, underlying their differential responses to drugs. Using a fitness landscape determined recently, we estimated that 13 amino acid variants, encoded by 44 codons, exist at the residue 93 of the NS5A protein, illustrating the massive diversity of accessible resistance pathways at specific loci. Accounting for this diversity, which our model enables, would help optimize drug combinations. Our model may be applied to describe the within-host evolution of other flaviviruses and inform vaccine design strategies.


Assuntos
Antivirais/farmacologia , Farmacorresistência Viral/genética , Efeito Fundador , Hepacivirus/genética , Hepatite C Crônica/genética , Mutação , Proteínas não Estruturais Virais/genética , Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/virologia , Humanos , Modelos Teóricos , Inibidores de Proteases/farmacologia
13.
Viruses ; 11(2)2019 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-30823509

RESUMO

Proteases are a major enzyme group playing important roles in a wide variety of biological processes in life forms ranging from viruses to mammalians. The aberrant activity of proteases can lead to various diseases; consequently, host proteases have been the focus of intense investigation as potential therapeutic targets. A wide range of viruses encode proteases which play an essential role in viral replication and, therefore, constitute attractive targets for the development of antiviral therapeutics. There are numerous examples of successful drug development targeting cellular and viral proteases, including antivirals against human immunodeficiency virus and hepatitis C virus. Most FDA-approved antiviral agents are peptidomimetics and macrocyclic compounds that interact with the active site of a targeted protease. Norovirus proteases are cysteine proteases that contain a chymotrypsin-like fold in their 3D structures. This review focuses on our group's efforts related to the development of norovirus protease inhibitors as potential anti-norovirus therapeutics. These protease inhibitors are rationally designed transition-state inhibitors encompassing dipeptidyl, tripeptidyl and macrocyclic compounds. Highly effective inhibitors validated in X-ray co-crystallization, enzyme and cell-based assays, as well as an animal model, were generated by launching an optimization campaign utilizing the initial hit compounds. A prodrug approach was also explored to improve the pharmacokinetics (PK) of the identified inhibitors.


Assuntos
Antivirais/farmacologia , Descoberta de Drogas , Norovirus/enzimologia , Replicação Viral/efeitos dos fármacos , Antivirais/química , Infecções por Caliciviridae/tratamento farmacológico , Modelos Moleculares , Peptídeo Hidrolases/metabolismo , Peptidomiméticos , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , Conformação Proteica , Proteínas Virais
14.
Expert Opin Investig Drugs ; 28(5): 421-433, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30907163

RESUMO

INTRODUCTION: Ixazomib is a new, orally administered, reversible proteasome inhibitor which is under investigation for the treatment of refractory/relapsed multiple myeloma (MM), systemic light chain amyloidosis (AL) and Waldenström macroglobulinemia (WM). Areas covered: This article covers the mechanism of action, pharmacology and clinical trial results of ixazomib while under investigation for the treatment of various lymphoproliferative disorders. We examine the findings from several phase 3 clinical trials (i) the pivotal TOURMALINE-MM1 study investigating ixazomib versus placebo in combination with lenalidomide and dexamethasone; (ii) the TOURMALINE-MM3 study investigating ixazomib versus placebo as a maintenance therapy in newly diagnosed MM following induction therapy and autologous stem cell transplantation; (iii) the TOURMALINE-MM2 study investigating ixazomib versus placebo in combination with lenalidomide and dexamethasone in patients with newly diagnosed MM; and (iv) TOURMALINE-AL1 investigating ixazomib plus dexamethasone in patients with relapsed/refractory AL amyloidosis. Finally, we explore early phase clinical studies of this agent in Waldenström macroglobulinemia. Expert opinion: A key advantage of ixazomib is that it could allow an efficacious treatment approach to MM and other lymphoproliferative disorders through a convenient oral administration route. Ixazomib could soon be used in combination treatment regimens, but more work is necessary to define the place of this agent going forward.


Assuntos
Antineoplásicos/administração & dosagem , Compostos de Boro/administração & dosagem , Glicina/análogos & derivados , Transtornos Linfoproliferativos/tratamento farmacológico , Administração Oral , Animais , Antineoplásicos/farmacologia , Compostos de Boro/farmacologia , Dexametasona/administração & dosagem , Drogas em Investigação/administração & dosagem , Drogas em Investigação/farmacologia , Glicina/administração & dosagem , Glicina/farmacologia , Humanos , Amiloidose de Cadeia Leve de Imunoglobulina/tratamento farmacológico , Amiloidose de Cadeia Leve de Imunoglobulina/fisiopatologia , Transtornos Linfoproliferativos/fisiopatologia , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/fisiopatologia , Inibidores de Proteases/administração & dosagem , Inibidores de Proteases/farmacologia , Macroglobulinemia de Waldenstrom/tratamento farmacológico , Macroglobulinemia de Waldenstrom/fisiopatologia
15.
Eur J Med Chem ; 168: 447-460, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30844608

RESUMO

A new series of 4-phenylcoumarin derivatives was synthesized starting from (2-oxo-4-phenyl-2H-chromen-7-yloxy) acetic acid hydrazide 3. Evaluation of the target compounds for their antiviral activity against hepatitis A virus revealed that the ethylthiosemicarbazide derivative 7b was the most potent virucidal agent (IC50 = 3.1 µg/ml, TI = 83). The Schiff's bases 14c and 14b demonstrated the highest virustatic effects against viral adsorption and replication, respectively (14c; IC50 = 8.5 µg/ml, TI = 88 and 14b; IC50 = 10.7 µg/ml, TI = 91). Furthermore, compounds 7b, 14b and 14c were tested against HAV 3C protease and showed significant inhibition effects (Ki = 1.903, 0.104 and 0.217 µM, respectively). The remarkable inhibitory effect expressed by the three target compounds against HAV 3C protease prompted us to expand our research on HRV 3C protease, a structurally related enzyme of the same family, and interestingly, the three target compounds displayed significant inhibitory effect against HRV 3C protease (IC50 = 16.10, 4.13 and 6.30 µM, respectively). Moreover, the active compounds 7b, 14b and 14c were docked within the pocket site of HAV 3C protease (PDB code: 2HAL) illustrating a strong H-profile with the key amino acids Gly170 and Cys172 similar to the co-crystallized ligand. Furthermore, 3D-pharmacophore and quantitative structure activity relationship (QSAR) models were generated to explore the structural requirements for the observed antiviral activity.


Assuntos
Antivirais/farmacologia , Cumarínicos/farmacologia , Desenho de Drogas , Vírus da Hepatite A/efeitos dos fármacos , Inibidores de Proteases/farmacologia , Proteínas Virais/antagonistas & inibidores , Antivirais/síntese química , Antivirais/química , Cumarínicos/síntese química , Cumarínicos/química , Cisteína Endopeptidases/metabolismo , Relação Dose-Resposta a Droga , Vírus da Hepatite A/metabolismo , Humanos , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteases/síntese química , Inibidores de Proteases/química , Relação Quantitativa Estrutura-Atividade , Proteínas Virais/metabolismo
16.
Drug Discov Ther ; 13(1): 17-21, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30880317

RESUMO

The expression of leucine aminopeptidase 3 (LAP3) is associated with the prognosis for and malignant transformation of many types of tumors. Therefore, a LAP3 inhibitor may represent a new strategy for cancer therapy. Evaluating the suppression of enzyme activity by an LAP3 inhibitor is essential. Right now, leucine aminopeptidases (LAPs) purified from the porcine kidneys are the only enzymes that can be used to evaluate the suppression of enzyme activity by an LAP3 inhibitor. This approach cannot accurately reflect the suppression of human LAP3 by an inhibitor. The current study developed a new method with which to evaluate the suppression of enzyme activity by an LAP3 inhibitor. Total protein from K562 cells seldom catalyzed the LAP3 substrate. A lentivirus was used to induce K562 cells to overexpress LAP3 (K562-LAP3). After puromycin screening, flow cytometry data indicated that 98.8% of cells expressed green fluorescent protein. The expression of LAP3 in K562-LAP3 cells was also assessed using Western blotting. K562-LAP3 cells were lysed with ultrasonication. Total protein was used as an enzyme source and L-leucine p-nitroaniline hydrochloride was used as a substrate to measure enzyme activity. Total protein from K562-LAP3 cells catalyzed the substrate more than that from K562 cells did. The LAP3 inhibitor ubenimex was used as a positive control to evaluate the suppression of LAP3 enzyme activity. Results indicated that ubenimex significantly inhibited the enzyme activity of LAP3. This approach provides a convenient and accurate way to evaluate the suppression of enzyme activity by an LAP3 inhibitor.


Assuntos
Leucina/análogos & derivados , Leucil Aminopeptidase/antagonistas & inibidores , Leucil Aminopeptidase/biossíntese , Inibidores de Proteases/farmacologia , Células A549 , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Humanos , Células K562 , Lentivirus/genética , Lentivirus/metabolismo , Leucina/farmacologia , Leucil Aminopeptidase/genética , Células MCF-7
17.
Cardiovasc Diabetol ; 18(1): 40, 2019 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-30909895

RESUMO

OBJECTIVE: Diabetic nephropathy (DN) is characterized by glomerular and tubulointerstitial injury, proteinuria and remodeling. Here we examined whether the combination of an inhibitor of neprilysin (sacubitril), a natriuretic peptide-degrading enzyme, and an angiotensin II type 1 receptor blocker (valsartan), suppresses renal injury in a pre-clinical model of early DN more effectively than valsartan monotherapy. METHODS: Sixty-four male Zucker Obese rats (ZO) at 16 weeks of age were distributed into 4 different groups: Group 1: saline control (ZOC); Group 2: sacubitril/valsartan (sac/val) (68 mg kg-1 day-1; ZOSV); and Group 3: valsartan (val) (31 mg kg-1 day-1; ZOV). Group 4 received hydralazine, an anti-hypertensive drug (30 mg kg-1 day-1, ZOH). Six Zucker Lean (ZL) rats received saline (Group 5) and served as lean controls (ZLC). Drugs were administered daily for 10 weeks by oral gavage. RESULTS: Mean arterial pressure (MAP) increased in ZOC (+ 28%), but not in ZOSV (- 4.2%), ZOV (- 3.9%) or ZOH (- 3.7%), during the 10 week-study period. ZOC were mildly hyperglycemic, hyperinsulinemic and hypercholesterolemic. ZOC exhibited proteinuria, hyperfiltration, elevated renal resistivity index (RRI), glomerular mesangial expansion and podocyte foot process flattening and effacement, reduced nephrin and podocin expression, tubulointerstitial and periarterial fibrosis, increased NOX2, NOX4 and AT1R expression, glomerular and tubular nitroso-oxidative stress, with associated increases in urinary markers of tubular injury. None of the drugs reduced fasting glucose or HbA1c. Hypercholesterolemia was reduced in ZOSV (- 43%) and ZOV (- 34%) (p < 0.05), but not in ZOH (- 13%) (ZOSV > ZOV > ZOH). Proteinuria was ameliorated in ZOSV (- 47%; p < 0.05) and ZOV (- 30%; p > 0.05), but was exacerbated in ZOH (+ 28%; p > 0.05) (ZOSV > ZOV > ZOH). Compared to ZOC, hyperfiltration was improved in ZOSV (p < 0.05 vs ZOC), but not in ZOV or ZOH. None of the drugs improved RRI. Mesangial expansion was reduced by all 3 treatments (ZOV > ZOSV > ZOH). Importantly, sac/val was more effective in improving podocyte and tubular mitochondrial ultrastructure than val or hydralazine (ZOSV > ZOV > ZOH) and this was associated with increases in nephrin and podocin gene expression in ZOSV (p < 0.05), but not ZOV or ZOH. Periarterial and tubulointerstitial fibrosis and nitroso-oxidative stress were reduced in all 3 treatment groups to a similar extent. Of the eight urinary proximal tubule cell injury markers examined, five were elevated in ZOC (p < 0.05). Clusterin and KIM-1 were reduced in ZOSV (p < 0.05), clusterin alone was reduced in ZOV and no markers were reduced in ZOH (ZOSV > ZOV > ZOH). CONCLUSIONS: Compared to val monotherapy, sac/val was more effective in reducing proteinuria, renal ultrastructure and tubular injury in a clinically relevant animal model of early DN. More importantly, these renoprotective effects were independent of improvements in blood pressure, glycemia and nitroso-oxidative stress. These novel findings warrant future clinical investigations designed to test whether sac/val may offer renoprotection in the setting of DN.


Assuntos
Aminobutiratos/farmacologia , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Nefropatias Diabéticas/prevenção & controle , Glomérulos Renais/efeitos dos fármacos , Túbulos Renais/efeitos dos fármacos , Inibidores de Proteases/farmacologia , Tetrazóis/farmacologia , Animais , Pressão Arterial/efeitos dos fármacos , Biomarcadores/metabolismo , Glicemia/metabolismo , Nefropatias Diabéticas/sangue , Nefropatias Diabéticas/patologia , Nefropatias Diabéticas/fisiopatologia , Modelos Animais de Doenças , Fibrose , Glomérulos Renais/metabolismo , Glomérulos Renais/fisiopatologia , Glomérulos Renais/ultraestrutura , Túbulos Renais/metabolismo , Túbulos Renais/fisiopatologia , Túbulos Renais/ultraestrutura , Lipídeos/sangue , Masculino , Neprilisina/antagonistas & inibidores , Estresse Nitrosativo/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Proteinúria/fisiopatologia , Proteinúria/prevenção & controle , Ratos Zucker , Fatores de Tempo
18.
Chem Pharm Bull (Tokyo) ; 67(2): 155-158, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30713276

RESUMO

Aminopeptidase N, also known as CD13, is a transmembrance protease with many functions. CD13 is involved in inflammatory diseases and cancers. A convenient and reliable laboratory test method for detecting the suppressing effects of enzyme activity would be useful for study of CD13 inhibitors. Porcine CD13 (pCD13) was traditionally considered an enzyme source but has significant practical disadvantages. pCD13 is not a human source, and the accuracy and reliability of experimental results are greatly reduced. In this study, a modified detection method with K562-CD13 monoclonal cells, a human-derived cell line, was established to detect the suppressing effects of enzyme activity by the CD13 inhibitor. In this method, K562-CD13 monoclonal cells were used as enzyme source and L-leucine p-nitroaniline hydrochloride as substrate. Using CD13 enzyme activity analyses, we found that the ability of the catalytic substrate was weaker in K562 cells than in the other cell lines, and K562-CD13 cells expressed significantly higher levels of CD13 enzyme activity than parental K562 cells. The enzyme activity of CD13 was detected with the new method after ubenimex treatment. The enzyme activity was significantly inhibited by ubenimex in a dose-dependent manner. In summary, this study proposes a sensitive, stable, and objective laboratory method for detecting the inhibitory effect of the CD13 inhibitor.


Assuntos
Bioensaio , Antígenos CD13/antagonistas & inibidores , Inibidores de Proteases , Animais , Humanos , Células K562 , Leucina/análogos & derivados , Leucina/farmacologia , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , Suínos
19.
J Pept Sci ; 25(4): e3154, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30734395

RESUMO

Cathepsin D (Cath D) is overexpressed and hypersecreted by malignant tumors and involved in the progress of tumor invasion, proliferation, metastasis, and apoptosis. Cath D has been considered as a potential target to treat cancer. Our previous studies revealed that tasiamide B derivatives TB-9 and TB-11 exhibited high potent inhibition against Cath D and other aspartic proteases, but their molecular weights are still high, and the role of each residue is unknown yet. Based on this, two series of tasiamide B derivatives have been designed, synthesized, and evaluated for their inhibitory activity against Cath D/Cath E/BACE1. Enzymatic assays revealed that the target compound 1 with lower molecule weight showed good inhibitory activity against Cath D with IC50 of 3.29 nM and satisfactory selectivity over Cath E (72-fold) and BACE1 (295-fold), which could be a valuable template for the design of highly potent and selective Cath D inhibitors.


Assuntos
Catepsina D/antagonistas & inibidores , Desenho de Drogas , Oligopeptídeos/farmacologia , Inibidores de Proteases/farmacologia , Catepsina D/metabolismo , Relação Dose-Resposta a Droga , Estrutura Molecular , Oligopeptídeos/síntese química , Oligopeptídeos/química , Inibidores de Proteases/síntese química , Inibidores de Proteases/química , Relação Estrutura-Atividade
20.
Chemosphere ; 222: 364-370, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30710762

RESUMO

Two recombinant protease inhibitors from Bauhinia bauhinioides, rBbKI (kallikrein inhibitor) and rBbCI (cruzipain inhibitor) were evaluated for insecticidal activity against workers and soldiers of Nasutitermes corniger (order: Isoptera; family: Termitidae) through the inhibitors' effect on the insect's gut enzymes. The inhibitor rBbKI was more effective than rBbCI in inhibiting the termite's gut enzymes. The kallikrein inhibitor showed termiticidal activity in workers with an LC50 of 0.9 mg mL-1 after 4 days. Conversely, rBbKI did not affect the survival of soldiers and rBbCI did not show termiticidal activity against N. corniger. The two inhibitors showed different specificity towards the termite's gut enzymes, representing interesting tools to characterize N. corniger enzymes. The different effects of rBbKI and rBbCI on the termite's enzymes and survival may be linked to slight structural differences between these inhibitors.


Assuntos
Bauhinia/química , Inseticidas/farmacologia , Isópteros/enzimologia , Inibidores de Proteases/farmacologia , Animais , Cisteína Endopeptidases , Humanos , Calicreínas/antagonistas & inibidores , Proteínas de Protozoários/antagonistas & inibidores , Especificidade por Substrato
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