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1.
Chem Biodivers ; 16(8): e1900318, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31364803

RESUMO

Sponges from freshwater environments, unlike marine's, are poorly known producers of natural compounds with medicinal purposes. Amazonian sponges produce massive large specimens and are widely spread, taxonomically diverse and their metabolites could represent a new frontier on unusual natural products to treat diseases such as Alzheimer's and Malaria. Species of Metania and Drulia (Metaniidae) genera are major contributors to the fauna of Amazonian freshwater sponges. Methanolic extracts from several species from these genera had their inhibitory activities evaluated in vitro, for parasite Plasmodium falciparum and acetyl and butyrylcholinesterase enzymes (AChE and BChE). All extracts were able to inhibit AChE, although no activity was observed towards BChE. Drulia uruguayensis extract was the most potent, inhibiting AChE with IC50 =1.04 mg/mL. For antiplasmodial activity, all species showed inhibition to P. falciparum, but Metania reticulata being the most efficient with IC50 =2.7 µg/mL. Mass spectrometry analyses evidenced the presence of fatty acids and sterols in active extracts.


Assuntos
Antiprotozoários/química , Inibidores da Colinesterase/química , Poríferos/química , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Animais , Antiprotozoários/isolamento & purificação , Antiprotozoários/farmacologia , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/metabolismo , Ácidos Graxos/análise , Ácidos Graxos/química , Plasmodium falciparum/efeitos dos fármacos , Poríferos/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Esteróis/química
2.
Chem Biol Interact ; 311: 108788, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31401088

RESUMO

Aqueous solutions of chlorpyrifos oxon are used to study the ability of chlorpyrifos oxon to catalyze protein crosslinking. Assays for protein crosslinking can avoid artifacts by using information on the stability of chlorpyrifos oxon in solution. We undertook to determine the half-life of chlorpyrifos oxon in aqueous solution because literature values do not exist. The rate of conversion of chlorpyrifos oxon to 3,5,6-trichloro-2-pyridinol was measured at 23 °C in 20 mM TrisCl pH 8 and pH 9 by recording loss of absorbance at 290 nm for chlorpyrifos oxon and increase in absorbance at 320 nm for 3,5,6-trichloro-2-pyridinol. The half-life of chlorpyrifos oxon was 20.9 days at pH 8 and 6.7 days at pH 9. Literature reports for the stability of other organophosphorus toxicants were summarized because our current studies suggest that other organophosphorus toxicants are also crosslinking agents.


Assuntos
Clorpirifos/análogos & derivados , Ésteres/química , Organofosfatos/química , Água/química , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Clorpirifos/química , Clorpirifos/metabolismo , Meia-Vida , Humanos , Concentração de Íons de Hidrogênio , Hidrólise , Organofosfatos/metabolismo , Hidróxido de Sódio/química , Espectrofotometria
3.
Chem Biol Interact ; 310: 108735, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31276662

RESUMO

Organophosphates (OPs) irreversibly inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. The reactivation of these inhibited enzymes is paramount for their normal function. Present study evaluates reactivation potency of two newly developed oximes, K456 and K733, against paraoxon (POX)-inhibited human-RBC-AChE and human-plasma-BChE in comparison to reported reactivator, pralidoxime (2-PAM). In vitro studies showed higher intrinsic toxicities of both oximes than 2-PAM for AChE. No substantial reactivation of hBChE was noted by tested concentration. Contrary to 2-PAM, the in silico study predicted lower binding free energies for both oximes. However, the detailed interaction study revealed inability of oximes to interact with catalytic anionic site of AChE and hBChE in contrast to 2-PAM. Both in vitro and in silico studies conclude that K456 and K733 are unlikely to be used as reactivators of paraoxon-inhibited AChE or BChE.


Assuntos
Inibidores da Colinesterase/farmacologia , Reativadores da Colinesterase/farmacologia , Oximas/farmacologia , Paraoxon/antagonistas & inibidores , Compostos de Piridínio/farmacologia , Acetilcolinesterase/química , Butirilcolinesterase/química , Eritrócitos/enzimologia , Humanos , Paraoxon/farmacologia
4.
Chem Biol Interact ; 310: 108737, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31279792

RESUMO

AIMS: K117 and K127 are bis-pyridinium aldoximes but K117 is a bis-pyridinium bis-aldoxime while K127 has only one single aldoxime in addition to its amide substituent. Is there any difference in pharmacokinetics in these compounds that otherwise have the same chemical structure? Both K117 and K127 are developed as antidotes in acetylcholinesterase and butyrylcholinesterase poisoning in terrorist attacks or intoxication with other organophosphorous compounds. Their distributions have been scouted in the bodies of rats. MAIN METHODS: White male Wistar rats were intramuscularly injected. The animals were sacrificed, tissue samples were homogenized, and either K117 or K127 concentrations were determined using reversed-phase high-performance liquid chromatography. KEY FINDINGS: Both K117 and K127 were present in all tissues that were analyzed including blood (serum), the brains, cerebrospinal fluid, the eyes, livers, kidneys, lungs and testes. Their pharmacokinetics and body distributions are similar. SIGNIFICANCE: Either K117 or K127 meets the essential requirements for antidotes. Dose dependence and kinetics of their distribution were compared to that of other pyridinium aldoximes.


Assuntos
Antídotos/farmacocinética , Organofosfatos/antagonistas & inibidores , Oximas/farmacocinética , Compostos de Piridínio/farmacocinética , Acetilcolinesterase/química , Animais , Butirilcolinesterase/química , Substâncias para a Guerra Química/farmacocinética , Inibidores da Colinesterase/farmacocinética , Reativadores da Colinesterase/farmacocinética , Oximas/análise , Compostos de Piridínio/análise , Ratos , Ratos Wistar , Distribuição Tecidual
5.
Chem Biol Interact ; 310: 108753, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31319075

RESUMO

Multitarget ligands (MTL) based on sterically hindered phenol and containing a quaternary ammonium moiety (SHP-n-Q) were synthesized. These compounds are inhibitors of cholinesterases with antioxidant properties. The inhibitory selectivity is 10-fold potent for BChE than for AChE. IC50 of SHP-n-Q for BChE is 20 µM. SHP-n-Q and their nanosystems exhibit more pronounced antioxidant properties than the synthetic antioxidant (hindered phenol, butylated hydroxytoluene). These compounds display a low hemolytic activity against human red blood cells. The nanotechnological approach was used to increase the bioavailability of SHP-n-Q derivatives. For water soluble SHP-n-Q derivative, the self-assembled structures have a size close to 100 nm at critical association concentration (0.01 M). Mixed cationic liposomes based on l-α-phosphatidylcholine and SHP-n-Q of 100 nm diameter were prepared. The stability, encapsulation efficacy and release from liposomes of a model drug, Rhodamine B, depend on the structure of SHP-n-Q. Cationic liposomes based on l-α-phosphatidylcholine and SHP-3-Q show a good stability in time (1year) and a sustained release (>65 h). They are promising templates for the development of anti-Alzheimer MT-drug delivery systems.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Fenóis/química , Acetilcolinesterase/química , Compostos de Amônio , Antioxidantes/farmacologia , Butirilcolinesterase/química , Inibidores da Colinesterase/farmacologia , Humanos , Lipossomos/química , Nanoestruturas , Fenóis/síntese química , Relação Estrutura-Atividade
6.
Chem Biol Interact ; 308: 350-356, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31173753

RESUMO

Activation of human butyrylcholinesterase by small quaternary ammonium ions is known. Here, additional ligands in this series are presented: edrophonium and choline, and the reactivator pyridine-2-aldoxime methochloride. Kinetic analysis of the progress curves with these compounds indicates the mechanism of enhanced deacylation by the ligand bound to the catalytic anionic site (Trp82) at the base of the active site. The larger, bis-quaternary ligands examined, as propidium, hexamethonium, decamethonium, and bis-thiocholine, show only competitive inhibition of butyrylcholinesterase, by preventing substrate approach. This hypothesis of enhanced deacylation was tested for reactivation of methanesulfonylfluoride-inactivated butyrylcholinesterase, a complex analogous to organophosphate-aged cholinesterases. The combination of substrate/products and pyridine-2-aldoxime methochloride improved butyrylcholinesterase activity over 2 h of continuous measurements, before which time substrate depletion prevailed. Similar reactivation of Torpedo californica acetylcholinesterase was unsuccessful, but both of these cholinesterases regain some activity if they have been inhibited and aged for days by diisopropylfluorophosphate.


Assuntos
Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/metabolismo , Oximas/metabolismo , Butirilcolinesterase/química , Domínio Catalítico , Colina/química , Colina/metabolismo , Inibidores da Colinesterase/química , Edrofônio/química , Edrofônio/metabolismo , Humanos , Cinética , Ligantes , Oximas/química , Especificidade por Substrato
7.
Chem Biol Interact ; 309: 108707, 2019 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-31194956

RESUMO

Alzheimer's disease (AD) is a slow but progressive neurodegenerative disease. One of the pathological hallmarks of AD is the progressive accumulation of ß-amyloid (Aß) in the form of senile plaques, and Aß insult to neuronal cells has been identified as one of the major causes of AD onset. In the present study, we investigated the anti-AD potential of four flavonoids, naringenin, didymin, prunin, and poncirin, by evaluating their ability to inhibit acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and ß-site amyloid precursor protein cleaving enzyme 1 (BACE1). All four flavonoids displayed promising inhibitory activity against AChE, BChE, and BACE1. Structure-activity relationships suggested that glycosylation of naringenin at sugar moieties, and at different positions of the glycosidic linkage, might be closely associated with anti-AD potential. Kinetic and docking studies showed the lowest binding energy and highest affinity for the mixed, competitive, and non-competitive type inhibitors didymin, prunin, and poncirin. Hydrophobic interactions and the number of hydrogen bonds determined the strength of the protein-inhibitor interaction. We also examined the neuroprotective mechanisms by which flavonoids act against Aß25-35-induced toxicity in PC12 cells. Exposure of PC12 cells to 10 µM Aß25-35 for 24 h resulted in a significant decrease in cell viability. In addition, pretreatment of PC12 cells with different concentrations of flavonoids for 1 h significantly reversed the effects of Aß. Furthermore, treatment with the most active flavonoid, didymin, significantly reduced BACE1, APPsß, and C99 expression levels in a dose-dependent manner, without affecting amyloid precursor protein (APP) levels in the amyloidogenic pathway. Together, our results indicate that flavonoids, and in particular didymin, exhibit inhibitory activity in vitro, and may be useful in the development of therapeutic modalities for the treatment of AD.


Assuntos
Acetilcolinesterase/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Butirilcolinesterase/metabolismo , Flavanonas/química , Glicosídeos/farmacologia , Agregados Proteicos/efeitos dos fármacos , Acetilcolinesterase/química , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/farmacologia , Animais , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Sítios de Ligação , Butirilcolinesterase/química , Domínio Catalítico , Sobrevivência Celular/efeitos dos fármacos , Glicosídeos/química , Cinética , Simulação de Acoplamento Molecular , Células PC12 , Fragmentos de Peptídeos/farmacologia , Substâncias Protetoras/química , Substâncias Protetoras/farmacologia , Ratos , Relação Estrutura-Atividade
8.
Chem Biol Interact ; 309: 108699, 2019 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-31202688

RESUMO

The crystal structures of truncated forms of cholinesterases provide good models for assessing the role of non-covalent interactions in dimer assembly in the absence of cross-linking disulfide bonds. These structures identify the four-helix bundle that serves as the interface for formation of acetylcholinesterase and butyrylcholinesterase dimers. Here we performed a theoretical comparison of the structural and energetic factors governing dimerization. This included identification of inter-subunit and intra-subunit hydrogen bonds and hydrophobic interactions, evaluation of solvent-accessible surfaces, and estimation of electrostatic contributions to dimerization. To reveal the contribution to dimerization of individual amino acids within the contact area, free energy perturbation alanine screening was performed. Markov state modelling shows that the loop between the α13 and α14 helices in BChE is unstable, and occupies 4 macro-states. The order of magnitude of mean first passage times between these macrostates is ~10-8 s. Replica exchange molecular dynamics umbrella sampling calculations revealed that the free energy of human BChE dimerization is -15.5 kcal/mol, while that for human AChE is -26.4 kcal/mol. Thus, the C-terminally truncated human butyrylcholinesterase dimer is substantially less stable than that of human acetylcholinesterase. An animated Interactive 3D Complement (I3DC) is available in Proteopedia at http://proteopedia.org/w/Journal:CHEMBIOINT:1.


Assuntos
Acetilcolinesterase/química , Butirilcolinesterase/química , Acetilcolinesterase/metabolismo , Sequência de Aminoácidos , Butirilcolinesterase/metabolismo , Dimerização , Humanos , Interações Hidrofóbicas e Hidrofílicas , Cadeias de Markov , Simulação de Dinâmica Molecular , Conformação Proteica em alfa-Hélice , Alinhamento de Sequência , Eletricidade Estática , Termodinâmica
9.
Eur J Med Chem ; 177: 414-424, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31158754

RESUMO

Due to the role of butyrylcholinesterase (BChE) in acetylcholine hydrolysis in the late stages of the Alzheimer's disease (AD), inhibitors of butyrylcholinesterase (BChE) have been recently envisaged, besides acetylcholinesterase (AChE) inhibitors, as candidates for treating mild-to-moderate AD. Herein, synthesis and AChE/BChE inhibition activity of some twenty derivatives of 1,2,3,4,5,6-hexahydroazepino[4,3-b]indole (HHAI) is reported. Most of the newly synthesized HHAI derivatives achieved the inhibition of both ChE isoforms with IC50s in the micromolar range, with a structure-dependent selectivity toward BChE. Apparently, molecular volume and lipophilicity do increase selectivity toward BChE, and indeed the N2-(4-phenylbutyl) HHAI derivative 15d, which behaves as a mixed-type inhibitor, resulted the most potent (IC50 0.17 µM) and selective (>100-fold) inhibitor toward either horse serum and human BChE. Moreover, 15d inhibited in vitro self-induced aggregation of neurotoxic amyloid-ß (Aß) peptide and displayed neuroprotective effects in neuroblastoma SH-SY5Y cell line, significantly recovering (P < 0.001) cell viability when impaired by Aß1-42 and hydrogen peroxide insults. Overall, this study highlighted HHAI as useful and versatile scaffold for developing new small molecules targeting some enzymes and biochemical pathways involved in the pathogenesis of AD.


Assuntos
Azepinas/farmacologia , Inibidores da Colinesterase/farmacologia , Indóis/farmacologia , Fármacos Neuroprotetores/farmacologia , Peptídeos beta-Amiloides/metabolismo , Azepinas/síntese química , Azepinas/química , Azepinas/metabolismo , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Domínio Catalítico , Linhagem Celular Tumoral , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/metabolismo , Relação Dose-Resposta a Droga , Desenho de Drogas , Depuradores de Radicais Livres/síntese química , Depuradores de Radicais Livres/química , Depuradores de Radicais Livres/metabolismo , Depuradores de Radicais Livres/farmacologia , Humanos , Indóis/síntese química , Indóis/química , Indóis/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/metabolismo , Fragmentos de Peptídeos/metabolismo , Ligação Proteica/efeitos dos fármacos , Multimerização Proteica/efeitos dos fármacos , Relação Estrutura-Atividade
10.
Eur J Med Chem ; 178: 243-258, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31185414

RESUMO

To address the multifactorial nature of Alzheimer's Disease (AD), a multi-target-directed ligand approach was herein developed. As a follow-up of our previous studies, a small library of newly designed 2-arylbenzofuran derivatives was evaluated towards cholinesterases and cannabinoid receptors. The two most promising compounds, 8 and 10, were then assessed for their neuroprotective activity and for their ability to modulate the microglial phenotype. Compound 8 emerged as able to fight AD from several directions: it restored the cholinergic system by inhibiting butyrylcholinesterase, showed neuroprotective activity against Aß1-42 oligomers, was a potent and selective CB2 ligand and had immunomodulatory effects, switching microglia from the pro-inflammatory M1 to the neuroprotective M2 phenotype. Derivative 10 was a potent CB2 inverse agonist with promising immunomodulatory properties and could be considered as a tool for investigating the role of CB2 receptors and for developing potential immunomodulating drugs addressing the endocannabinoid system.


Assuntos
Benzofuranos/farmacologia , Inibidores da Colinesterase/farmacologia , Fatores Imunológicos/farmacologia , Fármacos Neuroprotetores/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Acetilcolinesterase/metabolismo , Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/antagonistas & inibidores , Animais , Benzofuranos/síntese química , Benzofuranos/química , Benzofuranos/metabolismo , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Células CHO , Domínio Catalítico , Linhagem Celular Tumoral , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/metabolismo , Cricetulus , Desenho de Drogas , Humanos , Fatores Imunológicos/síntese química , Fatores Imunológicos/química , Fatores Imunológicos/metabolismo , Camundongos , Microglia/efeitos dos fármacos , Simulação de Acoplamento Molecular , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/metabolismo , Fragmentos de Peptídeos/antagonistas & inibidores , Ligação Proteica , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/metabolismo , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/metabolismo
11.
Chem Biol Interact ; 308: 372-376, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31152736

RESUMO

According to recent research advance, it is interesting to identify new, potent and selective inhibitors of human butyrylcholinesterase (BChE) for therapeutic treatment of both the Alzheimer's disease (AD) and heroin abuse. In this study, we carried out a structure-based virtual screening followed by in vitro activity assays, with the goal to identify new inhibitors that are selective for BChE over acetylcholinesterase (AChE). As a result, a set of new, selective inhibitors of human BChE were identified from natural products with solanaceous alkaloid scaffolds. The most active one of the natural products (compound 1) identified has an IC50 of 16.8 nM against BChE. It has been demonstrated that the desirable selectivity of these inhibitors for BChE over AChE is mainly controlled by three key residues in the active site cavity, i.e. residues Q119, A277, and A328 in BChE versus the respective residues Y124, W286, and Y337 in AChE. Based on this structural insight, future rational design of new, potent and selective BChE inhibitors may focus on these key structural differences in the active site cavity.


Assuntos
Butirilcolinesterase/química , Inibidores da Colinesterase/química , Alcaloides de Solanáceas/química , Sítios de Ligação , Butirilcolinesterase/metabolismo , Domínio Catalítico , Inibidores da Colinesterase/metabolismo , Humanos , Concentração Inibidora 50 , Simulação de Acoplamento Molecular , Alcaloides de Solanáceas/metabolismo , Relação Estrutura-Atividade
12.
Comput Biol Chem ; 80: 463-471, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31170562

RESUMO

A series of novel tacrine derivatives as multifunctional agents with potential inhibitory effects on both acetylcholinesterase(AChE) and butyrylcholinesterase (BuChE) enzymes for the treatment of Alzheimer's disease(AD), were applied to alignment independent 3D-QSAR methods using Pentacle software. In this studies, GRID-independent molecular descriptors (GRIND) analysis have been applied to characterize important interactions between enzymes and the studied compounds. Two H-bond acceptor groups as well as hydrophobic properties of tacrine rings for AChE and two H-bond acceptor on the carbonyl group of chromene and NH of amid group for BuChE, with positive effects on their inhibitory potency have been identified. The obtained 3D-QSAR models have been analyzed and validated. The statistical quality of the QSAR model for AChE, r2 = 0.87, q2 = 0.56 and for BuChE, r2 = 0.96, q2 = 0.70 was resulted. Using these models, novel structures have been designed and pIC50 of them were predicted. Molecular docking studies were also conducted on AChE (1ACJ) and BuChE (4BDS) and promising results in good agreement with 3D-QSAR studies were obtained.


Assuntos
Benzopiranos/metabolismo , Inibidores da Colinesterase/metabolismo , Nootrópicos/metabolismo , Tacrina/metabolismo , Acetilcolinesterase/química , Doença de Alzheimer/tratamento farmacológico , Animais , Benzopiranos/química , Butirilcolinesterase/química , Domínio Catalítico , Inibidores da Colinesterase/química , Desenho de Drogas , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Nootrópicos/química , Ligação Proteica , Relação Quantitativa Estrutura-Atividade , Tacrina/química , Torpedo
13.
Chem Biol Interact ; 309: 108712, 2019 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-31201777

RESUMO

The recent intentional use of nerve agents and pesticides in Europe and Afghanistan highlights the need for an effective countermeasure against organophosphates (OP) toxins. The most developed pretreatment candidate to date is plasma (native) human butyrylcholinesterase (HuBChE), which is limited in availability and because of its 1:1 stoichiometry with OPs, a large dose will present challenges when delivered parenterally both in terms of pharmacokinetics and manageability in the field. A tetrameric recombinant (r) form of human BChE produced in CHO-K1 cells with similar structure, in vivo stability and antidotal efficacy as the native form, has been developed to deliver rHuBChE as an aerosol (aer) to form a pulmonary bioshield capable of neutralizing inhaled OPs in situ and prevent AChE inhibition in the blood and in the brain; the latter associated with the symptoms of OP toxicity. Previous proof-of-concept macaque studies demonstrated that delivery of 9 mg/kg using a microsprayer inserted down the trachea, resulted in protection against an inhaled dose of 15ug/kg of aer-paraoxon (aer-Px) given 72 h later. In the present studies, pulmonary delivery of rHuBChE in macaques was achieved using Aerogen vibrating mesh nebulizers, similar to that used for human self-administration. The promising findings indicate that despite the poor lung deposition observed in macaques using nebulizers (13-20%), protective levels of RBC-AChE were still present in the blood even when exposure aer-Px (55 µg/kg) was delayed for five days. This long term retention of 5 mg/kg rHuBChE deposited in the lung bodes well for the use of an aer-rHuBChE pretreatment in humans where a user-friendly customized nebulizer with increased lung deposition up to 50% will provide even longer protection at a lower dose.


Assuntos
Aerossóis/química , Butirilcolinesterase/química , Paraoxon/química , Animais , Butirilcolinesterase/genética , Butirilcolinesterase/metabolismo , Células CHO , Cricetinae , Cricetulus , Feminino , Humanos , Pulmão/metabolismo , Macaca , Masculino , Nebulizadores e Vaporizadores , Paraoxon/toxicidade , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/sangue , Proteínas Recombinantes/química
14.
Chem Biol Interact ; 307: 154-157, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31071335

RESUMO

Butyrylcholinesterase (BChE) is a serine hydrolase widely distributed throughout the body. It provides protection against administrated or inhaled poisons by hydrolyzing or sequestering the toxic compounds. The most frequent genetic variant of BCHE gene - K variant (p.A539T) is located in the C-terminal tetramerization domain, outside of the catalytic center. Many studies tried to reveal the nature of the lower activity of BChE K-variant but results and conclusions were often contradictory. The aim of this study is to estimate K allele frequency and its coexisting alterations in BCHE gene in a population of 162 individuals, as well as, assess influence on the enzyme activity in serum. We present three haplotypes of BChE-K variant, two of them coexist in strong linkage disequilibrium with alterations in 5'UTR (rs1126680), intron 2 (rs55781031) or in exon 2 (rs1799807). We demonstrate a negative role of these alterations on enzyme activity. By oneself BCHE-K (with no other alterations in BCHE gene) haplotype exhibits wild type enzyme activity. Based on our previous and presented results we conclude that SNPs localized outside the coding sequence, in 5'UTR or/and in intron 2 of BCHE gene, but not solely in K-variant alteration (p.A539T) itself, are responsible for reduced enzyme activity.


Assuntos
Butirilcolinesterase/metabolismo , Regiões 5' não Traduzidas , Adulto , Butirilcolinesterase/química , Butirilcolinesterase/genética , Éxons , Feminino , Haplótipos , Humanos , Íntrons , Cinética , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único
15.
Eur J Med Chem ; 177: 198-211, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31136894

RESUMO

A series of 3-amino-substituted rutacecarpine derivatives were synthesized to identify novel multitarget-directed ligands (MTDLs) for the treatment of Alzheimer's disease (AD). Biological evaluation showed that most of the synthesized compounds inhibited butyrylcholinesterase (BuChE) and exerted antioxidant effects. Among the synthesized compounds, 6n was subjected to further biological evaluation. Lineweaver-Burk plotting and molecular modeling illustrated that 6n bound simultaneously to the peripheral anionic site (PAS) and catalytic sites (CAS) of BuChE. Furthermore, 6n modulated Aß aggregation; chelated biometals; presented good absorption, distribution, metabolism, excretion, and toxicity properties; and showed remarkable neuroprotective activity. Previous research has shown that the optimized compound 6n has considerable potential for development as an MTDL for the treatment of AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores da Colinesterase/farmacologia , Substâncias Protetoras/farmacologia , Sulfonamidas/farmacologia , Peptídeos beta-Amiloides/metabolismo , Animais , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Linhagem Celular Tumoral , Quelantes/síntese química , Quelantes/química , Quelantes/farmacocinética , Quelantes/farmacologia , Inibidores da Colinesterase/síntese química , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacocinética , Desenho de Drogas , Humanos , Ligantes , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Substâncias Protetoras/síntese química , Substâncias Protetoras/química , Substâncias Protetoras/farmacocinética , Multimerização Proteica/efeitos dos fármacos , Ratos , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/química , Sulfonamidas/farmacocinética
16.
Chem Biol Interact ; 308: 113-119, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31100275

RESUMO

Aflatoxin M1 (AFM1) is a mycotoxin produced by Aspergillus fungi and found in contaminated milk, breastfeed and dairy products, being highly toxic and carcinogenic to humans and other mammalian species. It is also produced in the human body as a metabolite of aflatoxin B1 (AFB1), one of the most toxic natural products known. Previous studies have shown that AFM1 is a potential inhibitor of the enzyme acetylcholinesterase (AChE), and therefore, a potential neurotoxic agent. In this work, surface screening (SS) and molecular dynamics (MD) simulation on human acetylcholinesterase AChE (HssAChE) were performed to corroborate literature data regarding preferential binding sites and type of inhibition. Also, an inedited theoretical study on the interactions of AFM1 with human butyrylcholinesterase (HssBChE) was performed. In vitro inhibition tests on both enzymes were done to support theoretical results. MD simulations suggested the catalytic anionic site of HssAChE as the preferential binding site for AFM1 and also that this metabolite is not a good inhibitor of HssBChE, corroborating previous studies. In vitro assays also corroborated molecular modeling studies by showing that AFM1 did not inhibit BChE and was able to inhibit AChE, although not as much as AFB1.


Assuntos
Acetilcolinesterase/química , Aflatoxina M1/química , Butirilcolinesterase/química , Acetilcolinesterase/metabolismo , Aflatoxina B1/química , Aflatoxina B1/metabolismo , Aflatoxina M1/metabolismo , Aspergillus/metabolismo , Sítios de Ligação , Butirilcolinesterase/metabolismo , Domínio Catalítico , Humanos , Simulação de Dinâmica Molecular , Propriedades de Superfície , Termodinâmica
17.
Chem Biol Interact ; 308: 101-109, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31100281

RESUMO

Eight derivatives of 4-aminoquinolines differing in the substituents attached to the C(4)-amino group and C(7) were synthesised and tested as inhibitors of human acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Both enzymes were inhibited by all of the compounds with inhibition constants (Ki) ranging from 0.50 to 50 µM exhibiting slight selectivity toward AChE over BChE. The most potent inhibitors of AChE were compounds with an n-octylamino chain or adamantyl group. The shortening of the chain length resulted in a decrease in AChE inhibition by 5-20 times. Docking studies revealed that the quinoline group within the AChE active site was positioned in the choline binding site, while the C(4)-amino group substituents, depending on their lipophilicity, could establish hydrogen bonds or π-interactions with residues of the peripheral anionic site. The most potent inhibitors of BChE were compounds with the most voluminous substituent on C(4)-amino group (adamantyl) or those with a stronger electron withdrawing substituent on C(7) (trifluormethyl group). Based on AChE inhibition, compounds with an n-octylamino chain or adamantyl substituent were shown to possess the capacity for further development as potential drugs for treatment of neurodegenerative diseases.


Assuntos
Acetilcolinesterase/química , Aminoquinolinas/química , Butirilcolinesterase/química , Inibidores da Colinesterase/química , Acetilcolinesterase/genética , Acetilcolinesterase/metabolismo , Aminoquinolinas/metabolismo , Sítios de Ligação , Barreira Hematoencefálica/metabolismo , Butirilcolinesterase/genética , Butirilcolinesterase/metabolismo , Domínio Catalítico , Inibidores da Colinesterase/metabolismo , Humanos , Cinética , Simulação de Acoplamento Molecular , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação
18.
Chem Biodivers ; 16(5): e1800436, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30957958

RESUMO

Two series of novel coumarin derivatives, substituted at 3 and 7 positions with aminoalkoxy groups, are synthesized, characterized, and screened. The effect of amine substituents and the length of cross-linker are investigated in acetyl- and butyrylcholinesterase (AChE and BuChE) inhibition. Target compounds show moderate to potent inhibitory activities against AChE and BuChE. 3-(3,4-Dichlorophenyl)-7-[4-(diethylamino)butoxy]-2H-chromen-2-one (4y) is identified as the most potent compound against AChE (IC50 =0.27 µm). Kinetic and molecular modeling studies affirmed that compound 4y works in a mixed-type way and interacts simultaneously with the catalytic active site (CAS) and peripheral anionic site (PAS) of AChE. In addition, compound 4y blocks ß-amyloid (Aß) self-aggregation with a ratio of 44.11 % at 100 µm and significantly protects PC12 cells from H2 O2 -damage in a dose-dependent manner.


Assuntos
Cumarínicos/química , Ligantes , Fármacos Neuroprotetores/química , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/metabolismo , Animais , Apoptose/efeitos dos fármacos , Sítios de Ligação , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Domínio Catalítico , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Inibidores da Colinesterase/uso terapêutico , Cumarínicos/farmacologia , Cumarínicos/uso terapêutico , Humanos , Peróxido de Hidrogênio/toxicidade , Concentração Inibidora 50 , Cinética , Simulação de Acoplamento Molecular , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Células PC12 , Ratos , Relação Estrutura-Atividade
19.
Chem Biol Interact ; 306: 138-146, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31009643

RESUMO

A computer-designed mutant of human butyrylcholinesterase (BChE), N322E/E325G, with a novel catalytic triad was made. The catalytic triad of the wild-type enzyme (S198·H438·E325) was replaced by S198·H438·N322E in silico. Molecular dynamics for 1.5 µs and Markov state model analysis showed that the new catalytic triad should be operative in the mutant enzyme, suggesting functionality. QM/MM modeling performed for the reaction of wild-type BChE and double mutant with echothiophate showed high reactivity of the mutant towards the organophosphate. A truncated monomeric (L530 stop) double mutant was expressed in Expi293 cells. Non-purified transfected cell culture medium was analyzed. Polyacrylamide gel electrophoresis under native conditions followed by activity staining with BTC as the substrate provided evidence that the monomeric BChE mutant was active. Inhibition of the double mutant by echothiophate followed by polyacrylamide gel electrophoresis and activity staining showed that this enzyme slowly self-reactivated. However, because Expi293 cells secrete an endogenous BChE tetramer and several organophosphate-reacting enzymes, catalytic parameters and self-reactivation constants after phosphorylation of the new mutant were not determined in the crude cell culture medium. The study shows that the computer-designed double mutant (N322E/E325G) with a new catalytic triad (S198·H438·N322E) is a suitable template for design of novel active human BChE mutants that display an organophosphate hydrolase activity.


Assuntos
Biocatálise , Butirilcolinesterase/genética , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/farmacologia , Projeto Auxiliado por Computador , Iodeto de Ecotiofato/farmacologia , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Mutação , Butirilcolinesterase/química , Inibidores da Colinesterase/química , Iodeto de Ecotiofato/química , Células HEK293 , Humanos , Simulação de Acoplamento Molecular , Proteínas Mutantes/genética , Teoria Quântica
20.
Chem Biol Interact ; 307: 16-20, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31004594

RESUMO

Bispyridinium oximes with one (K865, K866, K867) or two (K868, K869, K870) ortho-positioned chlorine moiety, analogous to previously known K027, K048 and K203 oximes, and potent reactivators of human acetylcholinesterase (AChE) inhibited by nerve agents, were tested in the reactivation of human butyrylcholinesterase (BChE) inhibited by sarin, cyclosarin, VX, and tabun. A previously highlighted AChE reactivator, dichlorinated bispyridinium oxime with propyl linker (K868), was tested in more detail for reactivation of four nerve agent-BChE conjugates. Its BChE reactivation potency was showed to be promising when compared to the standard oximes used in medical practice, asoxime (HI-6) and pralidoxime (2-PAM), especially in case of sarin and tabun. This finding could be used in the pseudo-catalytic scavenging of the most nerve agents due to its cumulative capacity to reactivate both AChE and BChE.


Assuntos
Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/metabolismo , Agentes Neurotóxicos/metabolismo , Oximas/metabolismo , Butirilcolinesterase/química , Inibidores da Colinesterase/química , Ativação Enzimática/efeitos dos fármacos , Halogenação , Humanos , Cinética , Agentes Neurotóxicos/química , Oximas/química , Oximas/farmacologia , Compostos de Piridínio/química , Sarina/química , Sarina/metabolismo
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