Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Chem Biol Interact ; 345: 109540, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34139148

RESUMO

In the present study, fifteen benzimidazolyl-2-hydrazones 7a-7o of fluoro-, hydroxy- and methoxy-substituted benzaldehydes and 1,3-benzodioxole-5-carbaldehyde were synthesized and their structure was identified by IR, NMR, and elemental analysis. The compounds 7j 2-(3-hydroxybenzylidene)-1-(5(6)-methyl-1H-benzimidazol-2-yl)hydrazone and 7i 2-(3-hydroxybenzylidene)-1-(1H-benzimidazol-2-yl)hydrazone have exerted the strongest anthelmintic activity (100% after 24 h incubation period at 37 °C) against isolated muscle larvae of Trichinella spiralis in an in vitro experiment. The in vitro cytotoxicity assay towards MCF-7 breast cancer cells and mouse embryo fibroblasts 3T3 showed that the studied benzimidazolyl-2-hydrazones exhibit low to moderate cytotoxic effects. The ability of the studied benzimidazolyl-2-hydrazones to modulate microtubule polymerization was confirmed and suggested that their anthelmintic action is mediated through inhibition of the tubulin polymerization likewise the other known benzimidazole anthelmitics. It was also shown that the four most promising benzimidazolyl-2-hydrazones do not affect significantly the AChE activity even at high tested concentration, thus indicating that they do not have the potential for neurotoxic effects. The binding mode of compounds 7j and 7n in the colchicine-binding site of tubulin were clarified by molecular docking simulations. Taken together, these results demonstrate that for the synthesized benzimidazole derivatives the anthelmintic activity against T. spiralis and the inhibition of tubulin polymerization are closely related.


Assuntos
Benzimidazóis/química , Hidrazonas/química , Hidrazonas/farmacologia , Simulação de Acoplamento Molecular , Tubulina (Proteína)/metabolismo , Anti-Helmínticos/síntese química , Anti-Helmínticos/química , Anti-Helmínticos/metabolismo , Anti-Helmínticos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Técnicas de Química Sintética , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Hidrazonas/síntese química , Hidrazonas/metabolismo , Células MCF-7 , Conformação Proteica , Relação Estrutura-Atividade , Tubulina (Proteína)/química , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/química , Moduladores de Tubulina/metabolismo , Moduladores de Tubulina/farmacologia
2.
Molecules ; 26(6)2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33808584

RESUMO

Novel biocompatible compounds that stabilize proteins in solution are in demand for biomedical and/or biotechnological applications. Here, we evaluated the effect of six ionic liquids, containing mono- or dicholinium [Chol]1or2 cation and anions of charged amino acids such as lysine [Lys], arginine [Arg], aspartic acid [Asp], or glutamic acid [Glu], on the structure, thermal, and storage stability of the Rapana thomasiana hemocyanin (RtH). RtH is a protein with huge biomedicinal potential due to its therapeutic, drug carrier, and adjuvant properties. Overall, the ionic liquids (ILs) induce changes in the secondary structure of RtH. However, the structure near the Cu-active site seems unaltered and the oxygen-binding capacity of the protein is preserved. The ILs showed weak antibacterial activity when tested against three Gram-negative and three Gram-positive bacterial strains. On the contrary, [Chol][Arg] and [Chol][Lys] exhibited high anti-biofilm activity against E. coli 25213 and S. aureus 29213 strains. In addition, the two ILs were able to protect RtH from chemical and microbiological degradation. Maintained or enhanced thermal stability of RtH was observed in the presence of all ILs tested, except for RtH-[Chol]2[Glu].


Assuntos
Aminoácidos/química , Gastrópodes/química , Hemocianinas/química , Líquidos Iônicos/química , Animais
3.
Z Naturforsch C J Biosci ; 75(1-2): 23-30, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31926108

RESUMO

This is the first report on the modification of a hemocyanin from Helix lucorum (HlH), a large molluscan respiratory protein, with folic acid (FA). In a two-step synthetic reaction, we prepared samples of HlH conjugated with 20 and 50 FA residues denoted as FA-HlH-1 and FA-HlH-2, respectively. Comparison of the attenuated total reflectance-Fourier transform infrared spectra in the amide I band region showed a structural rearrangement in the HlH that is due to FA conjugation. The changes in the secondary structure were more noticeable for FA-HlH-2. The thermal stability of HlH was not significantly affected by the FA modification, which is consistent with the observed structural similarities with the native protein. Preliminary cytotoxicity assays showed that FA-HlH-1 and FA-HlH-2 stimulate fibroblast proliferation when applied in concentrations of 50 and 100 µg/well. A negligible reduction of fibroblast growth was observed only for FA-HlH-1 and FA-HlH-2, exposed to 200 µg/well for 48 h. We found that FA-HlH-2 exhibits a low to moderate cytotoxic effect on two breast cancer cell lines, which express folate receptors, a hormone-dependent (MCF-7) and a hormone-independent (MDA-MB-231). FA-HlH-2 protects nontransformed cells and affects only neoplastic cells, which could be an advantage, and the protein could have potential in combination with other chemotherapeutics.


Assuntos
Antineoplásicos/farmacologia , Ácido Fólico/farmacologia , Caracois Helix/química , Hemocianinas/farmacologia , Animais , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Ácido Fólico/química , Hemocianinas/química , Humanos , Células MCF-7 , Nanopartículas/química
4.
Acta Chim Slov ; 67(1): 253-259, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33558913

RESUMO

For the first time Helix lucorum hemocyanin (HlH) has been feruloylated. Two HlH conjugates with 40- and 120- ferulic acid residues were prepared, denoted as FA-HlH-1 and FA-HlH-2. Expectedly, the feruloylation of HlH induced a rearrangement of the protein molecule, a decrease in the ?-helical structure at the expense of ß-structures was observed. Besides, the FA-HlH conjugates were more prone to aggregation, which is probably due to the stabilization of the partially unfolded protein molecules by non-covalent bonding. Interestingly, the thermal stability of HlH was not affected by the modification. The native and feruloylated HlH were not toxic to normal fibroblasts (BJ cells). We observed a decrease in cell viability of breast cancer MCF-7 cells to about 66% after a 48h exposure to 70 µg/well of FA-HlH-2.


Assuntos
Ácidos Cumáricos/farmacologia , Caracois Helix/química , Hemocianinas/farmacologia , Acilação , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ácidos Cumáricos/síntese química , Ácidos Cumáricos/toxicidade , Hemocianinas/síntese química , Hemocianinas/toxicidade , Humanos
5.
Molecules ; 25(1)2019 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-31881750

RESUMO

The development of ionic liquids based on active pharmaceutical ingredients (API-ILs) is a possible solution to some of the problems of solid and/or hydrophobic drugs such as low solubility and bioavailability, polymorphism and an alternative route of administration could be suggested as compared to the classical drug. Here, we report for the first time the synthesis and detailed characterization of a series of ILs containing a cation amino acid esters and anion ketoprofen (KETO-ILs). The affinity and the binding mode of the KETO-ILs to bovine serum albumin (BSA) were assessed using fluorescence spectroscopy. All compounds bind in a distance not longer than 6.14 nm to the BSA fluorophores. The estimated binding constants (KA) are in order of 105 L mol-1, which is indicative of strong drug or IL-BSA interactions. With respect to the ketoprofen-BSA system, a stronger affinity of the ILs containing l-LeuOEt, l-ValOBu, and l-ValOEt cation towards BSA is clearly seen. Fourier transformed infrared spectroscopy experiments have shown that all studied compounds induced a rearrangement of the protein molecule upon binding, which is consistent with the suggested static mechanism of BSA fluorescence quenching and formation of complexes between BSA and the drugs. All tested compounds were safe for macrophages.


Assuntos
Líquidos Iônicos/síntese química , Líquidos Iônicos/metabolismo , Cetoprofeno/síntese química , Soroalbumina Bovina/metabolismo , Animais , Bovinos , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ésteres/síntese química , Ésteres/química , Transferência Ressonante de Energia de Fluorescência , Líquidos Iônicos/química , Líquidos Iônicos/toxicidade , Cetoprofeno/química , Cetoprofeno/toxicidade , Cinética , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Camundongos , Estrutura Secundária de Proteína , Células RAW 264.7 , Soroalbumina Bovina/química , Solubilidade , Solventes/química , Água/química
6.
AAPS PharmSciTech ; 18(4): 1402-1407, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27586964

RESUMO

Proteolytic enzymes are often used in dissolution testing of cross-linked gelatin capsules that do not conform to the dissolution specification. Their catalytic activity, however, can be affected when they are added to a dissolution media containing solubility enhancers, such as surfactants. The aim of this study was to assess the activity of pancreatic proteases in presence of four commonly used surfactants. We found that pancreatin exhibits remarkable proteolytic activity in the presence of Tween 80, even at the concentrations as high as 250 times its critical micelle concentration (cmc) in water, whereas, Triton X-100 enhanced the proteolytic activity of pancreatin when added at concentrations above its cmc in water. Both surfactants are non-ionic surfactants. On the other hand, sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB), which are ionic surfactants, have a detrimental effect on the proteolytic activity of pancreatin. For example, a 50% reduction of the pancreatin activity was found in samples which contain a minor amount of SDS (0.05% w/v) in comparison to a surfactant-free reaction. Additionally, no activity was observed for the pancreatin-SDS samples which were incubated for 30 min at 40°C prior to testing. CTAB had an impact on pancreatin activity at concentrations higher than its cmc. Data from this manuscript can be used as a benchmark for optimization of the dissolution procedures that require use of both surfactants and enzymes.


Assuntos
Pancreatina/química , Tensoativos/farmacologia , Proteólise , Dodecilsulfato de Sódio/farmacologia , Solubilidade
7.
Int J Biol Macromol ; 82: 798-805, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26478091

RESUMO

This is the first study on the surface modification of a hemocyanin from marine snail Rapana thomasiana (RtH) with series of imidazolium-based amino acid ionic liquids [emim][AA]. We monitored the induced by [emim][AA] conformational changes in RtH molecule and evaluated the effect of these ionic liquids (ILs) on the protein thermal stability. The cytotoxicity of all obtained RtH-[emim][AA] complexes was assessed toward breast cancer cells (MCF-7) and murine fibroblasts (3T3). As a whole, even small amounts of the tested ILs altered the secondary structure of RtH. The thermal denaturation of RtH in presence of [emim][AA] displayed multi-component transitions, which were shifted toward lower temperatures in comparison to those estimated for the native RtH. The profiles of the RtH-IL calorimetric curves show a clear dependence on the structure of the added salts. In addition, all RtH-[emim][AA] complexes exhibited an enhanced antiprofilerative activity of toward MCF-7 cells in comparison to that of the native RtH. The best results are observed for RtH-[emim][Leu], RtH-[emim][Trp] or RtH-[emim][Ile], which applied in concentration of 700 µg/mL inhibited the MCF-7 cell viability (for 24h) by 66, 63 and 53%, respectively. In addition, these IL-RtH complexes were less cytotoxic to 3T3 cells, i.e. they exhibited some cell specificity.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Gastrópodes , Hemocianinas/química , Hemocianinas/farmacologia , Líquidos Iônicos/química , Células 3T3 , Animais , Neoplasias da Mama , Sobrevivência Celular/efeitos dos fármacos , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Líquidos Iônicos/síntese química , Células MCF-7 , Camundongos , Estabilidade Proteica , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica
8.
J Enzyme Inhib Med Chem ; 26(4): 587-91, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21438711

RESUMO

A series of 4-alkylamino-2-ethoxycyclobut-3en-1,2-diones has been synthesized, characterized and their inhibitory effect on pancreatic lipase (PL) was evaluated. The compound 1 has shown relatively high potency (IC(50) = 0.11 mM) compared with the most effective anti-obesity drug, tetrahydrolipstatin (Orlistat) (IC(50) value = 0.08 mM). The compounds have showed good selectivity toward PL and did not affect the activity of trypsin, another digestive enzyme.


Assuntos
Ciclobutanos/farmacologia , Inibidores Enzimáticos/farmacologia , Lipase/antagonistas & inibidores , Pâncreas/enzimologia , Ciclobutanos/síntese química , Ciclobutanos/química , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Lipase/metabolismo , Estrutura Molecular , Estereoisomerismo , Relação Estrutura-Atividade , Tripsina/metabolismo
9.
FEBS J ; 276(9): 2589-98, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19476497

RESUMO

A new set of experimental kinetic data on the hydrolysis of a series of phenylacetyl p-substituted anilides catalyzed by penicillin G acylase from Escherichia coli (PGA) is presented in this article. The Hammett plot of log(k(cat,R)/k(cat,H)) versus sigma(p) (-) has three linear segments, which distinguishes the enzyme from the other N-terminal nucleophile hydrolases for which data are available. Three amino acids in the vicinity of the catalytic SerB1 (AsnB241, AlaB69, and GlnB23) were included in the quantum mechanical model. The stable structures and the transition states for acylation were optimized by molecular mechanical modeling and at the AM1 level of theory for three model substrates (with H, a methoxy group or a nitro group in the para position in the leaving group). Intrinsic interactions of several functional groups at the active site of PGA are discussed in relation to the catalytic efficiency of the enzyme. The energy barrier computed for the first step of acylation (the nucleophilic attack of SerB1) is lower than that for the second step (the collapse of the tetrahedral intermediate). However, the electronic properties of the substituent on the leaving group affect the structure of the second transition state. It is shown that the main chain carbonyl group of GlnB23 forms a hydrogen bond with the leaving group nitrogen, thus influencing the hydrolysis rate. On the basis of our computations, we propose an interpretation of the complex character of the Hammett plot for the reaction catalyzed by PGA. We suggest a modified scheme of the catalytic mechanism in which some of the intramolecular interactions essential for catalysis are included.


Assuntos
Aminoácidos/química , Hidrolases/química , Alanina/química , Catálise , Escherichia coli/enzimologia , Escherichia coli/metabolismo , Glutamina/química , Ligação de Hidrogênio , Hidrolases/metabolismo , Hidrólise , Cinética , Modelos Moleculares , Penicilina Amidase/química , Penicilina Amidase/metabolismo , Especificidade por Substrato
10.
Eur J Biochem ; 271(11): 2272-9, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15153118

RESUMO

Kinetic experiments with a substrate series of phenylacetyl-arylamides reveal that at least one polar group in the amine moiety is required for the proper orientation of the substrate in the large nucleophile-binding subsite of penicillin acylase of Escherichia coli. Quantum mechanical molecular modelling of enzyme-substrate interactions in the enzyme active site shows that in the case of substrates lacking local symmetry, the productive binding implies two nonsymmetrical arrangements with respect to the two positively charged guanidinium residues of ArgA145 and ArgB263. This indicates a crucial role of the specified arginine pair in the substrate- and stereoselectivity of penicillin acylase.


Assuntos
Arginina/fisiologia , Modelos Moleculares , Penicilina Amidase/química , Penicilina Amidase/metabolismo , Aminas/química , Arginina/química , Sítios de Ligação , Escherichia coli/enzimologia , Cinética , Teoria Quântica , Estereoisomerismo , Especificidade por Substrato
11.
Biochim Biophys Acta ; 1597(2): 335-8, 2002 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-12044911

RESUMO

The arylamidase activity of Zn-proteinase from Saccharomonospora canescens (NPS) was studied with series of peptide nitroanilides of varying amino acid sequence and N-acyl blocking groups. The partial mapping of the enzyme S(1), S(2), S(3), S(4) subsites shows that variations in all positions P(1) to P(4) in the substrate structure affect the catalytic efficiency. The importance of P(4)-S(4) and P(1)-S(1) interactions, which is a characteristic feature of the serine proteinases, is evidenced for the studied Zn-proteinases NPS and serralysin too. The presence of arylamidase activity in the case of Zn-proteinases-astacin EC 3.4.24.21 and serralysin EC 3.4.24.40 is correlated with some specific characteristics of their active site structure: penta-coordinated Zn(2+) and a tyrosyl residue as a fifth ligand to the Zn(2+). It is assumed that this tyrosyl residue plays a role in the productive binding and stabilization of the tetrahedral adduct formed during the reaction of enzyme-catalysed hydrolysis of peptide arylamides of corresponding length and sequence.


Assuntos
Actinomycetales/enzimologia , Aminopeptidases/metabolismo , Endopeptidases/metabolismo , Actinomycetales/genética , Sequência de Aminoácidos , Aminopeptidases/química , Aminopeptidases/genética , Caseínas , Endopeptidases/química , Endopeptidases/genética , Cinética , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Zinco/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...