RESUMO
Inflammation-induced choroidal neovascularization followed by the epithelial-mesenchymal transition (EMT) of retinal pigment epithelial cells (RPEs) is a cause of neovascular age-related macular degeneration (nAMD). RPE-derived myofibroblasts overproduce extracellular matrix, leading to subretinal fibrosis. We already have demonstrated that benzylphenylurea (BPU) derivatives inhibit the function of cancer-associated fibroblasts. Here, we investigated the anti-myofibroblast effects of BPU derivatives and examined such BPU activity on subretinal fibrosis. A BPU derivative, BPU17, exhibits the most potent anti-myofibroblast activity among dozens of BPU derivatives and inhibits subretinal fibrosis in a mouse model of retinal degeneration. Investigations with primary cultured RPEs reveal that BPU17 suppresses cell motility and collagen synthesis in RPE-derived myofibroblasts. These effects depend on repressing the serum response factor (SRF)/CArG-box-dependent transcription. BPU17 inhibits the expression of SRF cofactor, cysteine and glycine-rich protein 2 (CRP2), which activates the SRF function. Proteomics analysis reveals that BPU17 binds to prohibitin 1 (PHB1) and inhibits the PHB1-PHB2 interaction, resulting in mild defects in mitochondrial function. This impairment causes a decrease in the expression of CRP2 and suppresses collagen synthesis. Our findings suggest that BPU17 is a promising agent against nAMD and the close relationship between PHB function and EMT.
RESUMO
Inflammatory response induces phenotypic modulation of fibroblasts into myofibroblasts. Although transforming growth factor-ßs (TGF-ßs) evoke such transition, the details of the mechanism are still unknown. Here, we report that a LIM domain protein, cysteine-and glycine-rich protein 2 (CSRP2 [CRP2]) plays a vital role in the functional expression profile in myofibroblasts and cancer-associated fibroblasts (CAFs). Knock-down of CRP2 severely inhibits the expression of smooth muscle cell (SMC) genes, cell motility, and CAF-mediated collective invasion of epidermoid carcinoma. We elucidate the following molecular bases: CRP2 directly binds to myocardin-related transcription factors (MRTF-A/B [MRTFs]) and serum response factor (SRF) and stabilizes the MRTF/SRF/CArG-box complex to activate SMC gene expression. Furthermore, a three-dimensional structural analysis of CRP2 identifies the amino acids required for the CRP2-MRTF-A interaction. Polar amino acids in the C-terminal half (serine-152, glutamate-154, serine-155, threonine-156, threonine-157, and threonine-159 in human CRP2) are responsible for direct binding to MRTF-A. On the other hand, hydrophobic amino acids outside the consensus sequence of the LIM domain (tryptophan-139, phenylalanine-144, leucine-153, and leucine-158 in human CRP2) play a role in stabilizing the unique structure of the LIM domain.Key words: CRP2, 3D structure, myocardin-related transcription factor, myofibroblast, cancer-associated fibroblasts.
Assuntos
Regulação da Expressão Gênica , Miofibroblastos , Humanos , Células Cultivadas , Leucina/metabolismo , Miofibroblastos/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Fator de Crescimento Transformador beta/farmacologiaRESUMO
Brassinolide (BL) is a possible plant growth regulator in agriculture, but the presence of a steroid skeleton hampers the field application of BL in agriculture because of its high synthetic cost. We discovered NSBR1 as the first nonsteroidal BL-like compound using in silico technology. Searching for more potent BL-like compounds, we modified the structure of NSBR1 with respect to 2 benzene rings and the piperazine ring. The activity of synthesized compounds was measured in Arabidopsis hypocotyl elongation. The propyl group of butyryl moiety of NSBR1 was changed to various alkyl groups, such as straight, branched, and cyclic alkyl chains. Another substituent, F, at the ortho position of the B ring toward the piperazine ring was changed to other substituents. A methyl group was introduced to the piperazine ring. Most of the newly synthesized compounds with the 3,4-(OH)2 group at the A ring significantly elongated the hypocotyl of Arabidopsis.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Esteroides Heterocíclicos , Brassinosteroides , Piperazinas , Esteroides Heterocíclicos/farmacologiaRESUMO
Ecdysone agonists are a class of insecticides that activate the ecdysone receptor (EcR) heterodimerized with the ultraspiracle (USP). Here, we report a new luciferase reporter assay for ecdysone agonists. The assay employs mammalian HEK293T cells transiently transfected with the EcR and USP genes of Chilo suppressalis, along with the taiman (Tai) gene of Drosophila melanogaster that encodes a steroid receptor coactivator. This assay system gave results consistent with those of radioligand binding assays and showed sensitivity superior to that of the existing in vitro methods. In addition, use of the heterologous host cells precludes perturbation from intrinsic players of the ecdysone signaling, which is a potential drawback of insect cell-based methods. This reporter system is suitable for detailed structure-activity analysis of ecdysone agonists and will serve as a valuable tool for the rational design of novel insect growth regulators.
Assuntos
Proteínas de Drosophila , Inseticidas , Receptores de Esteroides , Animais , Humanos , Ecdisona/farmacologia , Ecdisona/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Células HEK293 , Receptores de Esteroides/genética , Receptores de Esteroides/metabolismo , Luciferases/genética , Hormônios Juvenis , Mamíferos/metabolismoRESUMO
Ecdysteroids act as molting hormones in insects and as nonhormonal anabolic agents and adaptogens in mammals. A wide range of ecdysteroid-containing herbal extracts are available worldwide as food supplements. The aim of this work was to study such an extract as a possible industrial source of new bioactive ecdysteroids. A large-scale chromatographic isolation was performed from an extract of Cyanotis arachnoidea roots. Ten ecdysteroids (1-10) including eight new compounds were isolated and characterized by extensive nuclear magnetic resonance studies. Highly unusual structures were identified, including a H-14ß (1, 2, 4, and 10) moiety, among which a 14ß(H)17ß(H) phytosteroid (1) is reported for the first time. Compounds with an intact side chain (4-10) and 11 other natural or semisynthetic ecdysteroids (11-21) were tested for insect ecdysteroid receptor (EcR) binding activity. Two new compounds, i.e., 14-deoxydacryhainansterone (5) and 22-oxodacryhainansterone (6), showed strong EcR binding activity (IC50 = 41.7 and 380 nM, respectively). Six compounds were identified as EcR agonists and another two as antagonists using a transgenic ecdysteroid reporter gene assay. The present results demonstrate that commercial C. arachnoidea extracts are rich in new, unusual bioactive ecdysteroids. Because of the lack of an authentic plant material, the truly biosynthetic or artifactual nature of these compounds cannot be confirmed.
Assuntos
Commelinaceae/química , Ecdisteroides/química , Fitosteróis/química , Extratos Vegetais/química , Receptores de Esteroides/metabolismo , Animais , Estrutura Molecular , Raízes de Plantas/química , Células Sf9RESUMO
Spider venom is a complex mixture of bioactive components, in which peptides play an important role by showing neurotoxicity or cytotoxicity. Disulfide-rich peptides are major components in the venom, but linear peptides without disulfide bridges are also present and often show antimicrobial activity. In this study, we analyzed the venom of the spider Lycosa poonaensis (Lycosidae) to find novel antimicrobial peptides using mass spectrometry. The result revealed that 120 out of 401 detected components were nondisulfide-bridged peptides. From them, the sequence of 2 peptides (lyp2370 and lyp1987) were determined by MS/MS analysis. The biological activity test revealed that lyp2370 has only weak antibacterial activity. On the other hand, lyp1987, which is identical to M-lycotoxin-Ls3b from the Lycosa singoriensi venom, showed significant antibacterial activity. The weak activity of lyp2370 was found to be due to the presence of a Glu residue on the hydrophilic face of its amphipathic α-helical structure.
Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Venenos de Aranha/química , Aranhas , Sequência de Aminoácidos , Animais , Interações Hidrofóbicas e Hidrofílicas , Conformação Proteica em alfa-Hélice , Espectrometria de Massas em TandemRESUMO
Cytochrome P450 (CYP) enzymes constitute a superfamily of heme-containing monooxygenases. CYPs are involved in the metabolism of many chemicals such as drugs and agrochemicals. Therefore, examining the metabolic reactions by each CYP isoform is important to elucidate their substrate recognition mechanisms. The clarification of these mechanisms may be useful not only for the development of new drugs and agrochemicals, but also for risk assessment of chemicals. In our previous study, we identified the metabolites of tebufenozide, an insect growth regulator, formed by two human CYP isoforms: CYP3A4 and CYP2C19. The accessibility of each site of tebufenozide to the reaction center of CYP enzymes and the susceptibility of each hydrogen atom for metabolism by CYP enzymes were evaluated by a docking simulation and hydrogen atom abstraction energy estimation at the density functional theory level, respectively. In this study, the same in silico prediction method was applied to the metabolites of tebufenozide derivatives by major human CYPs (CYP1A2, 2C9, 2C19, 2D6, and 3A4). In addition, the production rate of the metabolites by CYP3A4 was quantitively analyzed by frequency based on docking simulation and hydrogen atom abstraction energy using the classical QSAR approach. Then, the obtained QSAR model was applied to predict the sites of metabolism and the metabolite production order by each CYP isoform.
Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Hidrazinas/metabolismo , Simulação de Acoplamento Molecular , Teoria da Densidade Funcional , Humanos , Hidrazinas/química , Isoenzimas/metabolismo , Estrutura MolecularRESUMO
Most scorpions fluoresce under UV light. To date, two types of fluorescent compounds have been identified in scorpions, but it has been assumed that other unknown compounds may be responsible for the fluorescence. In this study, we isolated a fluorescent compound from the exuviae of the scorpion Liocheles australasiae identified as a macrocyclic diphthalate ester with a molecular mass of 496.2 Da. The same compound was also detected in extracts from four other scorpion species. This suggests that this compound is shared by multiple scorpion species, although its contribution to the cuticle fluorescence may be relatively small.
Assuntos
Venenos de Escorpião/química , Escorpiões/química , Sequência de Aminoácidos , Animais , Estrutura MolecularRESUMO
The ecdysone receptor (EcR) is an insect nuclear receptor that is activated by the molting hormone, 20-hydroxyecdysone. Because synthetic EcR ligands disrupt the normal growth of insects, they are attractive candidates for new insecticides. In this study, the Molecular Mechanics/Poisson-Boltzmann Surface Area (MM/PBSA) method was used to predict the binding activity of EcR ligands. Validity analyses using 40 known EcR ligands showed that the binding activity was satisfactorily predicted when the ligand conformational free energy term was introduced. Subsequently, this MM/PBSA method was applied to structure-based hierarchical virtual screening, and 12 candidate compounds were selected from a database of 3.8 million compounds. Five of these compounds were active in a cell-based competitive binding assay. The most potent compound is a simple proline derivative with low micromolar binding activity, representing a valuable lead compound for further structural optimization.
Assuntos
Proteínas de Insetos/antagonistas & inibidores , Inseticidas/química , Receptores de Esteroides/antagonistas & inibidores , Animais , Bases de Dados de Produtos Farmacêuticos , Desenho de Fármacos , Proteínas de Insetos/metabolismo , Insetos/efeitos dos fármacos , Insetos/metabolismo , Inseticidas/metabolismo , Inseticidas/toxicidade , Ligantes , Simulação de Dinâmica Molecular , Receptores de Esteroides/metabolismo , TermodinâmicaRESUMO
A novel insecticidal peptide (LaIT3) was isolated from the Liocheles australasiae venom. The primary structure of LaIT3 was determined by a combination of Edman degradation and MS/MS de novo sequencing analysis. Discrimination between Leu and Ile in MS/MS analysis was achieved based on the difference in side chain fragmentation assisted by chemical derivatization. LaIT3 was determined to be an 84-residue peptide with three intrachain disulfide bonds. The sequence similarity search revealed that LaIT3 belongs to the scorpine-like peptides consisting of two structural domains: an N-terminal α-helical domain and a C-terminal cystine-stabilized domain. As observed for most of the scorpine-like peptides, LaIT3 showed significant antibacterial activity against Escherichia coli, which is likely to be caused by its membrane-disrupting property.
Assuntos
Inseticidas/farmacologia , Venenos de Escorpião/química , Toxinas Biológicas/farmacologia , Sequência de Aminoácidos , Animais , Cromatografia Líquida de Alta Pressão , Gryllidae , Escorpiões , Homologia de Sequência de Aminoácidos , Espectrometria de Massas em Tandem , Toxinas Biológicas/química , Toxinas Biológicas/isolamento & purificaçãoRESUMO
4-Coumaroyl-CoA ligase (4CL) is ubiquitous in the plant kingdom, and plays a central role in the biosynthesis of phenylpropanoids such as lignins, flavonoids, and coumarins. 4CL catalyzes the formation of the coenzyme A thioester of cinnamates such as 4-coumaric, caffeic, and ferulic acids, and the regulatory position of 4CL in the phenylpropanoid pathway renders the enzyme an attractive target that controls the composition of phenylpropanoids in plants. In this study, we designed and synthesized mechanism-based inhibitors for 4CL in order to develop useful tools for the investigation of physiological functions of 4CL and chemical agents that modulate plant growth with the ultimate goal to produce plant biomass that exhibits features that are beneficial to humans. The acylsulfamide backbone of the inhibitors in this study was adopted as a mimic of the acyladenylate intermediates in the catalytic reaction of 4CL. These acylsulfamide inhibitors and the important synthetic intermediates were fully characterized using two-dimensional NMR spectroscopy. Five 4CL proteins with distinct substrate specificity from four plant species, i.e., Arabidopsis thaliana, Glycine max (soybean), Populus trichocarpa (poplar), and Petunia hybrida (petunia), were used to evaluate the inhibitory activity, and the half-maximum inhibitory concentration (IC50) of each acylsulfamide in the presence of 4-coumaric acid (100⯵M) was determined as an index of inhibitory activity. The synthetic acylsulfamides used in this study inhibited the 4CLs with IC50 values ranging from 0.10 to 722⯵M, and the IC50 values of the most potent inhibitors for each 4CL were 0.10-2.4⯵M. The structure-activity relationship observed in this study revealed that both the presence and the structure of the acyl group of the synthetic inhibitors strongly affect the inhibitory activity, and indicates that 4CL recognizes the acylsulfamide inhibitors as acyladenylate mimics.
Assuntos
Adenosina/análogos & derivados , Adenosina/química , Proteínas de Arabidopsis/antagonistas & inibidores , Coenzima A Ligases/antagonistas & inibidores , Inibidores Enzimáticos/química , Sulfonamidas/química , Adenosina/síntese química , Arabidopsis/enzimologia , Inibidores Enzimáticos/síntese química , Estrutura Molecular , Petunia/enzimologia , Populus/enzimologia , Glycine max/enzimologia , Relação Estrutura-Atividade , Especificidade por Substrato , Sulfonamidas/síntese químicaRESUMO
Scorpion venom contains various bioactive peptides. Among them, peptides having two different structural domains constitute a toxin family known as ß-KTx or scorpine-like peptides. These peptides consist of an α-helical structure in the N-terminal region and a cysteine-stabilized structure in the C-terminal region. This unique structure of ß-KTx peptides contributes to their diverse biological functions, but the importance of each domain for their activities is not fully understood. LaIT2 is a ß-KTx peptide isolated from the venom of the scorpion Liocheles australasiae, which shows both insecticidal and antimicrobial activities. In this study, we chemically synthesized full-length LaIT2 using a native chemical ligation technique as well as its N-terminally or C-terminally truncated single-domain analogs to evaluate structural factors important for the activities. Biological evaluation of these peptides revealed that the N-terminal α-helical domain of LaIT2 is essential for the expression of both insecticidal and antibacterial activities. This suggests that the disruption of membrane structures largely accounts for the biological activities of LaIT2.
Assuntos
Antibacterianos/farmacologia , Inseticidas/farmacologia , Venenos de Escorpião/síntese química , Venenos de Escorpião/farmacologia , Escorpiões/química , Animais , Antibacterianos/síntese química , Antibacterianos/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Gryllidae/efeitos dos fármacos , Inseticidas/síntese química , Inseticidas/química , Testes de Sensibilidade Microbiana , Domínios Proteicos , Venenos de Escorpião/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimentoRESUMO
Imidazothiadiazoles (ITDs) are a class of potent nonsteroidal ecdysone agonists with larvicidal activity. Previously, we performed the Hansch-Fujita type of quantitative structure-activity relationship (QSAR) analysis for ITD analogs (Yokoi et al., Pestic. Biochem. Physiol.2015, 120, 40-50). The activity was reasonably explained by hydrophobicity and electronegativity of substituents on the imidazothiadiazole ring system. However, the limited data points (nâ¯=â¯8) hampered the examination of other physicochemical parameters. In the present study, we expanded the library of ITD congeners and evaluated their receptor-binding affinity using intact Sf-9 cells. The QSAR analysis for the expanded set revealed the significance of the third physicochemical parameter, the negative steric effect for long substituents. We also evaluated the larvicidal activity of the synthesized compounds against Spodoptera litura; however, it was not correlated to the binding affinity. The results obtained here suggests that the pharmacokinetic properties must be improved to enhance the larvicidal activity of ITDs.
Assuntos
Imidazóis/farmacologia , Relação Quantitativa Estrutura-Atividade , Receptores de Esteroides/agonistas , Tiadiazóis/farmacologia , Animais , Sítios de Ligação/efeitos dos fármacos , Relação Dose-Resposta a Droga , Imidazóis/síntese química , Imidazóis/química , Estrutura Molecular , Células Sf9 , Spodoptera , Tiadiazóis/síntese química , Tiadiazóis/químicaRESUMO
Brassinolide (BL) and castasterone (CS) are the representative members of brassinosteroid class of plant steroid hormone having plant growth promoting activity. In this study, eleven CS analogs bearing a variety of side chains were synthesized to determine the effect of the side chain structures on the BL-like activity. The plant hormonal activity was evaluated in a dwarf rice lamina inclination assay, and the potency was determined as the reciprocal logarithm of the 50% effective dose (ED50) from each dose-response curve. The reciprocal logarithm of ED50 (pED50) was decreased dramatically upon deletion of the C-28 methyl group of CS. The introduction of oxygen-containing groups such as hydroxy, methoxy, and ethoxycarbonyl was also unfavorable to the activity. The pED50 was influenced by the geometry of carbon-carbon double bond between C-24 and C-25 (cis and trans), but the introduction of a fluorine atom at the C-25 position of the double bond did not significantly change the activity. The binding free energy (ΔG) was calculated for all ligand-receptor binding interactions using molecular dynamics, resulting that ΔG is linearly correlated with the pED50.
Assuntos
Colestanóis/química , Reguladores de Crescimento de Plantas/química , Sítios de Ligação , Brassinosteroides/química , Brassinosteroides/metabolismo , Brassinosteroides/farmacologia , Colestanóis/metabolismo , Colestanóis/farmacologia , Ligantes , Simulação de Acoplamento Molecular , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Reguladores de Crescimento de Plantas/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Estrutura Terciária de Proteína , Esteroides Heterocíclicos/química , Esteroides Heterocíclicos/metabolismo , Esteroides Heterocíclicos/farmacologiaRESUMO
A novel anti-mollusk conopeptide pn4c was isolated from the Conus pennaceus venom by repeated HPLC fractionation based on the activity against freshwater snails. The primary structure of pn4c was determined by the mass spectrometric de novo sequencing analysis. In addition, pn3a was isolated from the same fraction containing pn4c, as a peptide with unknown functions.
Assuntos
Caramujo Conus/química , Peptídeos/química , Peptídeos/isolamento & purificação , Peçonhas/química , Sequência de Aminoácidos , Animais , Peptídeos/metabolismoRESUMO
P-glycoprotein (P-gp) is a member of the ATP-binding cassette transporter family. It actively transports a wide variety of compounds out of cells to protect humans from xenobiotics. Thus, determining whether chemicals are substrates and/or inhibitors of P-gp is important in risk assessments of pharmacokinetic interactions among chemicals because P-gp-mediated transport processes play a significant role in their absorption and disposition. We previously reported that dibenzoylhydrazines (DBHs) such as tebufenozide and methoxyfenozide (agrochemicals) stimulated P-gp ATPase activity. However, it currently remains unclear whether these derivatives are transport substrates of P-gp and inhibit transport of other chemicals by P-gp. In the present study, in order to evaluate the interactions of DBHs with other chemicals in humans, we determined whether DBHs are P-gp transport substrates using both the in vitro bidirectional transport assay and the in vivo study of rats. In the in vivo study, we investigated the influence of P-gp inhibitors on the brain to plasma ratio of methoxyfenozide in rats. We also examined the inhibitory effects of DBHs on quinidine (a P-gp substrate) transport by P-gp in order to ascertain whether these derivatives are inhibitors of P-gp. Based on the results, DBHs were concluded to be weak P-gp transport substrates and moderate P-gp inhibitors. However, the risk of DBHs caused by interaction with other chemicals including drugs was considered to be low by considering the DBHs' potential as the substrates and inhibitors of P-gp as well as their plasma concentrations as long as DBHs are properly used.
Assuntos
Encéfalo/efeitos dos fármacos , Hidrazinas/farmacocinética , Hormônios Juvenis/farmacocinética , Praguicidas/farmacocinética , Subfamília B de Transportador de Cassetes de Ligação de ATP/antagonistas & inibidores , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Animais , Bioensaio , Encéfalo/metabolismo , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Humanos , Hidrazinas/sangue , Hidrazinas/toxicidade , Injeções Intravenosas , Hormônios Juvenis/sangue , Hormônios Juvenis/toxicidade , Masculino , Praguicidas/sangue , Praguicidas/toxicidade , Transporte Proteico , Quinidina/farmacocinética , Ratos Sprague-Dawley , Especificidade por Substrato , Suínos , Espectrometria de Massas em Tandem , TransfecçãoRESUMO
Brassinolide (BL) is a plant steroid hormone that is necessary for stem elongation and cell division. To date more than 70 steroidal BL-like compounds, which are collectively named as brassinosteroids, have been identified. However, non-steroidal compounds that mimic BL have not been reported yet, which can be used as plant growth regulators. Twenty-two non-steroidal compounds were screened from the database containing about 5 million compound structures using a pharmacophore-based in silico screening method. The crystal structure (PDB: 4LSX) of the BL receptor was used to generate a pharmacophore model required for in silico screening. Among 22 hit compounds, 15 compounds that are thought to be physicochemically acceptable were submitted to the in vivo rice lamina inclination assay. Although no compound showed BL like activity, three compounds were detected as BL antagonist. The most potent compound was an ester derivative of 1,4-diphenlenedimethanol and isoxazole-4-carboxylic acid, and the other two compounds contain 2-phenylfuran and pyrimidin-2(1H)-one moieties bridged by an ethenyl substructure. The 50% effective doses (ED50) for the antagonistic activity were in a range of 0.6-5nmol per plant. The inhibition of the lamina inclination by the most potent agonist was recovered by the co-application of BL in a dose-dependent manner.
Assuntos
Derivados de Benzeno/química , Brassinosteroides/agonistas , Brassinosteroides/antagonistas & inibidores , Isoxazóis/química , Metanol/química , Oryza/crescimento & desenvolvimento , Reguladores de Crescimento de Plantas/química , Esteroides Heterocíclicos/agonistas , Esteroides Heterocíclicos/antagonistas & inibidores , Derivados de Benzeno/farmacologia , Simulação por Computador , Isoxazóis/farmacologia , Metanol/farmacologia , Modelos Moleculares , Oryza/efeitos dos fármacos , Reguladores de Crescimento de Plantas/farmacologiaRESUMO
We previously demonstrated that dibenzoylhydrazines (DBHs) are not only P-glycoprotein (P-gp) substrates, but also inhibitors. In the present study, we evaluated the inhibition of P-gp-mediated quinidine transport by two series of DBHs and performed a classical QSAR analysis and docking simulation in order to investigate the mechanisms underlying P-gp substrate/inhibitor recognition. The results of the QSAR analysis identified the hydrophobic factor as the most important for inhibitory activities, while electronic and steric effects also influenced the activities. The different substituent effects observed in each series suggested the different binding modes of each series of DBHs, which was supported by the results of the docking simulation.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Transporte Biológico/efeitos dos fármacos , Hidrazinas/química , Hidrazinas/farmacologia , Quinidina/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/fisiologia , Animais , Humanos , Interações Hidrofóbicas e Hidrofílicas , Células LLC-PK1 , Simulação de Acoplamento Molecular , Relação Quantitativa Estrutura-Atividade , SuínosRESUMO
Over 200 components with molecular mass ranging mainly from 400 to 4000 Da were characterized from the venom of the vermivorous cone snail Conus fulgetrum that inhabit Egyptian Red Sea. One major component having a molecular mass of 2946 Da was purified by HPLC, and its primary structure was determined by a combination of Edman degradation and MS/MS analysis.