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1.
J Inorg Biochem ; 223: 111558, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34329998

RESUMEN

Photo-chemotherapy (PCT) reveals great potential in hepatocellular carcinoma (HCC) treatment, therefore the construct of smart PCT nano-agents with high photothermal conversion efficiency and accurate drug delivery is of great significant. Herein, a novel hybrid nanomaterial MGO-TCA-FA has been designed and constructed by grafting the triformyl cholic acid (TCA) and folic acid (FA) on the surface of Fe3O4 modified graphene oxide (MGO). The doxorubicin hydrochloride (DOX) as a model drug could be effectively loaded on the MGO-TCA-FA via hydrogen bonding and π-π stacking (the drug loading amount was 1040 mg/g). The formed MGO-TCA-FA@DOX has been developed to be an effective PCT nanoplatform with the advantages of multiple-targeted drug delivery, near-infrared light (NIR) and pH triggered drug release, and photothermal conversion efficiency. In vitro experiments showed that compared with other cancer cells and normal liver cells, MGO-TCA-FA@DOX could specifically target liver cancer cells and presented significant killing ability to liver cancer cells. More importantly, in vivo experiments indicated that PCT synergistic therapy (MGO-TCA-FA@DOX) revealed the best tumor inhibition (the tumor inhibition rate was about 85%) compared with chemotherapy and photothermal therapy alone. Thus, this study supplied a viable multiple-targeted PCT nano-agent for chemo-photothermal combination therapy of liver cancer.


Asunto(s)
Antineoplásicos/uso terapéutico , Portadores de Fármacos/uso terapéutico , Grafito/uso terapéutico , Neoplasias Hepáticas/tratamiento farmacológico , Nanocompuestos/uso terapéutico , Animales , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/efectos de la radiación , Línea Celular Tumoral , Ácidos Cólicos/química , Terapia Combinada/métodos , Doxorrubicina/química , Doxorrubicina/farmacocinética , Doxorrubicina/uso terapéutico , Portadores de Fármacos/química , Portadores de Fármacos/efectos de la radiación , Liberación de Fármacos , Quimioterapia , Óxido Ferrosoférrico/química , Ácido Fólico/química , Grafito/química , Grafito/efectos de la radiación , Humanos , Rayos Infrarrojos , Fenómenos Magnéticos , Ratones Endogámicos BALB C , Nanocompuestos/química , Nanocompuestos/efectos de la radiación , Terapia Fototérmica
2.
Arch Biochem Biophys ; 691: 108518, 2020 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-32735863

RESUMEN

To conduct biochemical studies in vitro, membrane proteins (MPs) must be solubilized with detergents. While detergents are great tools, they can also inhibit the biological activity and/or perturb oligomerization of individual MPs. Nanodisc scaffold peptide (NSPr), an amphipathic peptide analog of ApoA1, was recently shown to reconstitute detergent solubilized MPs into peptidiscs in vitro. Acyl-coenzyme A:cholesterol acyltransferase 1 (ACAT1), also known as sterol O-acyltransferase 1 (SOAT1), plays a key role in cellular cholesterol storage in various cell types and is a drug target to treat multiple human diseases. ACAT1 contains nine transmembrane domains (TMDs) and primarily forms a homotetramer in vitro and in intact cells; deletion of the N-terminal dimerization domain produces a homodimer with full retention in catalytic activity. ACAT1 is prone to inactivation by numerous detergents. Here we pursued the use of NSPr to overcome the detergent-induced inactivation of ACAT1 by generating near detergent-free ACAT1 peptidiscs. Based on native-PAGE analysis, we showed that NSPr reconstitutes ACAT1 into soluble peptidiscs, in which ACAT1 exists predominantly in oligomeric states greater than a homotetramer. The formation of these higher-order oligomeric states was independent of the N-terminal dimerization domain, suggesting that the oligomerization is mediated through hydrophobic interactions of multiple ACAT1 subunits. ACAT1 peptidiscs were still susceptible to heat-mediated inactivation, presumably due to the residual detergent (CHAPS) bound to ACAT1. We then conditioned ACAT1 with phosphatidylcholine (PC) to replace CHAPS prior to the formation of ACAT1 peptidiscs. The results showed, when PC was included, ACAT1 was present mainly in higher-order oligomeric states with greater enzymatic activity. With PC present, the enzymatic activity of ACAT1 peptidiscs was protected from heat-mediated inactivation. These results support the use of NSPr to create a near detergent-free solution of ACAT1 in peptidiscs for various in vitro studies. Our current results also raise the possibility that, under certain conditions, ACAT1 may form higher-order oligomeric states in vivo.


Asunto(s)
Péptidos/química , Esterol O-Aciltransferasa/química , Tensoactivos/química , Secuencia de Aminoácidos , Animales , Células CHO , Ácidos Cólicos/química , Cricetulus , Detergentes/química , Digitonina/química , Humanos , Dominios Proteicos , Multimerización de Proteína , Esterol O-Aciltransferasa/metabolismo
3.
PLoS One ; 14(8): e0221052, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31415606

RESUMEN

Protein solubility is a critical prerequisite to any proteomics analysis. Combination of urea/thiourea and 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) have been routinely used to enhance protein solubilization for oil palm proteomics studies in recent years. The goals of these proteomics analysis are essentially to complement the knowledge regarding the regulation networks and mechanisms of the oil palm fatty acid biosynthesis. Through omics integration, the information is able to build a regulatory model to support efforts in improving the economic value and sustainability of palm oil in the global oil and vegetable market. Our study evaluated the utilization of sodium deoxycholate as an alternative solubilization buffer/additive to urea/thiourea and CHAPS. Efficiency of urea/thiourea/CHAPS, urea/CHAPS, urea/sodium deoxycholate and sodium deoxycholate buffers in solubilizing the oil palm (Elaeis guineensis var. Tenera) mesocarp proteins were compared. Based on the protein yields and electrophoretic profile, combination of urea/thiourea/CHAPS were shown to remain a better solubilization buffer and additive, but the differences with sodium deoxycholate buffer was insignificant. A deeper mass spectrometric and statistical analyses on the identified proteins and peptides from all the evaluated solubilization buffers revealed that sodium deoxycholate had increased the number of identified proteins from oil palm mesocarps, enriched their gene ontologies and reduced the number of carbamylated lysine residues by more than 67.0%, compared to urea/thiourea/CHAPS buffer. Although only 62.0% of the total identified proteins were shared between the urea/thiourea/CHAPS and sodium deoxycholate buffers, the importance of the remaining 38.0% proteins depends on the applications. The only observed limitations to the application of sodium deoxycholate in protein solubilization were the interference with protein quantitation and but it could be easily rectified through a 4-fold dilution. All the proteomics data are available via ProteomeXchange with identifier PXD013255. In conclusion, sodium deoxycholate is applicable in the solubilization of proteins extracted from oil palm mesocarps with higher efficiency compared to urea/thiourea/CHAPS buffer. The sodium deoxycholate buffer is more favorable for proteomics analysis due to its proven advantages over urea/thiourea/CHAPS buffer.


Asunto(s)
Arecaceae/química , Ácido Desoxicólico/química , Detergentes/química , Aceite de Palma/química , Proteínas de Plantas/análisis , Proteómica , Tampones (Química) , Ácidos Cólicos/química , Proteínas de Plantas/química
4.
J Clin Oncol ; 35(30): 3410-3416, 2017 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-28834453

RESUMEN

Purpose Many patients with high-risk non-muscle-invasive bladder cancer (NMIBC) are either refractory to bacillus Calmette-Guerin (BCG) treatment or may experience disease relapse. We assessed the efficacy and safety of recombinant adenovirus interferon alfa with Syn3 (rAd-IFNα/Syn3), a replication-deficient recombinant adenovirus gene transfer vector, for patients with high-grade (HG) BCG-refractory or relapsed NMIBC. Methods In this open-label, multicenter (n = 13), parallel-arm, phase II study ( ClinicalTrials.gov identifier: NCT01687244), 43 patients with HG BCG-refractory or relapsed NMIBC received intravesical rAd-IFNα/Syn3 (randomly assigned 1:1 to 1 × 1011 viral particles (vp)/mL or 3 × 1011 vp/mL). Patients who responded at months 3, 6, and 9 were retreated at months 4, 7, and 10. The primary end point was 12-month HG recurrence-free survival (RFS). All patients who received at least one dose were included in efficacy and safety analyses. Results Forty patients received rAd-IFNα/Syn3 (1 × 1011 vp/mL, n = 21; 3 × 1011 vp/mL, n = 19) between November 5, 2012, and April 8, 2015. Fourteen patients (35.0%; 90% CI, 22.6% to 49.2%) remained free of HG recurrence 12 months after initial treatment. Comparable 12-month HG RFS was noted for both doses. Of these 14 patients, two experienced recurrence at 21 and 28 months, respectively, after treatment initiation, and one died as a result of an upper tract tumor at 17 months without a recurrence. rAd-IFNα/Syn3 was well tolerated; no grade four or five adverse events (AEs) occurred, and no patient discontinued treatment because of an adverse event. The most frequently reported drug-related AEs were micturition urgency (n = 16; 40%), dysuria (n = 16; 40%), fatigue (n = 13; 32.5%), pollakiuria (n = 11; 28%), and hematuria and nocturia (n = 10 each; 25%). Conclusion rAd-IFNα/Syn3 was well tolerated. It demonstrated promising efficacy for patients with HG NMIBC after BCG therapy who were unable or unwilling to undergo radical cystectomy.


Asunto(s)
Terapia Genética/métodos , Interferón-alfa/metabolismo , Neoplasias de la Vejiga Urinaria/terapia , Adenoviridae/genética , Administración Intravesical , Anciano , Anciano de 80 o más Años , Vacuna BCG/administración & dosificación , Ácidos Cólicos/química , Disacáridos/química , Resistencia a Antineoplásicos , Fatiga/etiología , Femenino , Terapia Genética/efectos adversos , Vectores Genéticos/administración & dosificación , Vectores Genéticos/genética , Humanos , Interferón alfa-2 , Interferón-alfa/química , Interferón-alfa/genética , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Invasividad Neoplásica , Recurrencia Local de Neoplasia , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Resultado del Tratamiento , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/patología , Trastornos Urinarios/etiología
5.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1036-1037: 149-156, 2016 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-27760404

RESUMEN

Spiralin is the most abundant protein of several species of spiroplasmas, helical, motile bacteria pathogenic for arthropods and plants. This amphiphilic protein is anchored to the outer face of the plasma membrane by a lipoylated N-terminal cysteine. Although spiroplasma pathogenicity in mammals is controversial, it was shown that spiralin is highly immunogenic and endowed with immunomodulatory activity. In this paper, we describe a high performance method for the purification of Spiroplasma melliferum spiralin under non-denaturing conditions. The protein was selectively extracted with 3-[(3-cholamidopropyl) dimethylammonio]-1-propyl sulfonate (CHAPS) from the membrane pre-treated with sodium dodecyl-N-sarcosinate (Sarkosyl), and purified to homogeneity by cation-exchange HPLC with an overall yield of ∼60%. Detergent-depleted, water-soluble micelles of spiralin displaying a mean diameter of 170Å, as evidenced by transmission electron microscopy, were obtained by dialysis detergent removal. Circular dichroism spectroscopy and cross immunoprecipitation assay of the purified spiralin strongly suggested that this purification method could retain the structural characteristics of the native spiralin. The strategy developed to purify spiralin (two successive selective extractions of membrane proteins with mild detergents followed by ion-exchange chromatography) should prove useful for the purification of membrane lipoproteins of other bacteria of the class Mollicutes including different pathogens for humans, animals and plants.


Asunto(s)
Proteínas de la Membrana Bacteriana Externa/aislamiento & purificación , Cromatografía por Intercambio Iónico/métodos , Spiroplasma/química , Proteínas de la Membrana Bacteriana Externa/química , Ácidos Cólicos/química , Cromatografía en Gel/métodos , Cromatografía Líquida de Alta Presión/métodos , Dicroismo Circular , Detergentes/química , Conformación Proteica , Desnaturalización Proteica , Sarcosina/análogos & derivados , Sarcosina/química
6.
Biochim Biophys Acta ; 1864(11): 1558-69, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27524699

RESUMEN

Human S100A9 (Calgranulin B) is a Ca(2+)-binding protein, from the S100 family, that often presents as a homodimer in myeloid cells. It becomes an important mediator during inflammation once calcium binds to its EF-hand motifs. Human RAGE protein (receptor for advanced glycation end products) is one of the target-proteins. RAGE binds to a hydrophobic surface on S100A9. Interactions between these proteins trigger signal transduction cascades, promoting cell growth, proliferation, and tumorigenesis. Here, we present the solution structure of mutant S100A9 (C3S) homodimer, determined by multi-dimensional NMR experiments. We further characterize the solution interactions between mS100A9 and the RAGE V domain via NMR spectroscopy. CHAPS is a zwitterionic and non-denaturing molecule widely used for protein solubilizing and stabilization. We found out that CHAPS and RAGE V domain would interact with mS100A9 by using (1)H-(15)N HSQC NMR titrations. Therefore, using the HADDOCK program, we superimpose two binary complex models mS100A9-RAGE V domain and mS100A9-CHAPS and demonstrate that CHAPS molecules could play a crucial role in blocking the interaction between mS100A9 and the RAGE V domain. WST-1 assay results also support the conclusion that CHAPS inhibits the bioactivity of mS100A9. This report will help to inform new drug development against cell proliferation.


Asunto(s)
Antineoplásicos/farmacología , Calgranulina B/química , Proliferación Celular/efectos de los fármacos , Ácidos Cólicos/farmacología , Células Epiteliales/efectos de los fármacos , Receptor para Productos Finales de Glicación Avanzada/química , Secuencia de Aminoácidos , Antineoplásicos/química , Sitios de Unión , Calgranulina B/genética , Calgranulina B/metabolismo , Línea Celular Tumoral , Ácidos Cólicos/química , Clonación Molecular , Células Epiteliales/metabolismo , Células Epiteliales/patología , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Mutación , Unión Proteica , Dominios Proteicos , Multimerización de Proteína , Estructura Secundaria de Proteína , Receptor para Productos Finales de Glicación Avanzada/antagonistas & inhibidores , Receptor para Productos Finales de Glicación Avanzada/genética , Receptor para Productos Finales de Glicación Avanzada/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Relación Estructura-Actividad
7.
Protein Expr Purif ; 124: 62-7, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27241126

RESUMEN

The adenosine A2A receptor (A2AR) is a much-studied class A G protein-coupled receptor (GPCR). For biophysical studies, A2AR is commonly purified in a detergent mixture of dodecylmaltoside (DDM), 3-(3-cholamidopropyl) dimethylammoniopropane sulfonate (CHAPS), and cholesteryl hemisuccinate (CHS). Here we studied the effects of CHAPS on the ligand binding activity and stability of wild type, full-length human A2AR. We also tested the cholesterol requirement for maintaining the active conformation of the receptor when solubilized in detergent micelles. To this end, the receptor was purified using DDM, DDM/CHAPS, or the short hydrocarbon chain lipid 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC, di-6:0PC). After solubilization in DDM, DDM/CHAPS, or DHPC micelles, although A2AR was found to retain its native-like fold, its binding ability was significantly compromised compared to DDM or DDM/CHAPS with CHS. It therefore appears that although cholesterol is not needed for A2AR to retain a native-like, α-helical conformation, it may be a critical component for high affinity ligand binding. Further, this result suggests that the conformational differences between the active and inactive protein may be so subtle that commonly used spectroscopic methods are unable to differentiate between the two forms, highlighting the need for activity measurements. The studies presented in this paper also underline the importance of the protein's purification history; i.e., detergents that interact with the protein during purification affect the ligand binding properties of the receptor in an irreversible manner.


Asunto(s)
Ésteres del Colesterol/química , Ácidos Cólicos/química , Éteres Fosfolípidos/química , Receptor de Adenosina A2A/química , Receptor de Adenosina A2A/aislamiento & purificación , Proteínas Recombinantes/química , Humanos , Estructura Secundaria de Proteína
8.
J Biomater Sci Polym Ed ; 27(9): 865-79, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27045998

RESUMEN

The specific interaction between bile acids and the bile acids transporters provides a promising way for hepatoma-targeted drug delivery. We synthesized an amphipathic polymer containing cholic acid (CA), the main bile acids in body, and prepared CA-functionalized nanoparticles to target hepatoma cells. Poly-[3-(4-vinylbenzonate)-7, 12-dihydroxy-5-cholan-24-oic acid] (PVBCA) was synthesized by introducing methyl cholate onto polyvinyl benzoate polymer backbone, and was characterized by (1)H-NMR, FT-IR, and GFC. PVBCA can be incorporated onto PLGA nanoparticles surface via the emulsion-solvent evaporation procedure, resulting in the nanoparticles carrying CA moieties on their surface. The binding of CA moieties to the bile acids' transporters on the cell membrane enhances the cellular uptake of the nanoparticles significantly. The SMMC-7721 cell uptake of PVBCA-decorated nanoparticles increases with amount of incorporated PVBCA and is 2- to 2.8-fold higher than that of the normal PLGA nanoparticles. By exclusion of specific endocytosis pathways using chemical inhibitors, we found that the uptake mechanism of PVBCA-decorated nanoparticles was mainly attributed to clathrin-and-caveolae-independent endocytosis, which was distinct from that of PLGA nanoparticles. The present study provides a simple and versatile method for hepatoma-targeted delivery of nanoparticles.


Asunto(s)
Carcinoma Hepatocelular/patología , Ácido Cólico/química , Ácidos Cólicos/química , Portadores de Fármacos/química , Neoplasias Hepáticas/patología , Nanopartículas/química , Polímeros/química , Polivinilos/química , Línea Celular Tumoral , Técnicas de Química Sintética , Portadores de Fármacos/metabolismo , Endocitosis , Humanos
9.
Curr Protoc Protein Sci ; 84: 6.13.1-6.13.24, 2016 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-27038270

RESUMEN

This unit describes a straightforward and efficient method of using sarkosyl to solubilize and recover difficult recombinant proteins, such as GST- and His6 -tagged fusion proteins, that are overexpressed in E. coli. This protocol is especially useful for rescuing recombinant proteins overexpressed in M9 minimal medium. Sarkosyl added to lysis buffers helps with both protein solubility and cell lysis. Higher percentage sarkosyl (up to 10%) can extract >95% of soluble protein from inclusion bodies. In the case of sarkosyl-solubilized GST-fusion proteins, batch-mode affinity purification requires addition of a specific ratio of Triton X-100 and CHAPS, while sarkosyl-solubilized His6 -tagged fusion proteins can be directly purified on Ni(2+) resin columns. Proteins purified by this method could be widely used in biological assays, structure analysis and mass spectrum assay.


Asunto(s)
Ácidos Cólicos/química , Cuerpos de Inclusión/química , Octoxinol/química , Proteínas Recombinantes de Fusión/aislamiento & purificación , Sarcosina/análogos & derivados , Betaína/química , Escherichia coli/genética , Glutatión Transferasa/genética , Histidina/genética , Ingeniería de Proteínas/métodos , Pliegue de Proteína , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/aislamiento & purificación , Sarcosina/química , Sarcosina/aislamiento & purificación , Solubilidad , Sorbitol/química
10.
Steroids ; 105: 59-67, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26607331

RESUMEN

Bile acids, the end products of cholesterol metabolism, activate multiple mechanisms through the interaction with membrane G-protein coupled receptors including the bile acid receptor GPBAR1 and nuclear receptors such as the bile acid sensor, farnesoid X receptor (FXR). Even if dual FXR/GPBAR1 agonists are largely considered a novel opportunity in the treatment of several liver and metabolic diseases, selective targeting of one of these receptors represents an attractive therapeutic approach for a wide range of disorders in which dual modulation is associated to severe side effects. In the present study we have investigated around the structure of LCA generating a small library of cholane derivatives, endowed with dual FXR agonism/GPBAR1 antagonism. To the best of our knowledge, this is the first report of bile acid derivatives able to antagonize GPBAR1.


Asunto(s)
Ácidos y Sales Biliares/farmacología , Ácidos Cólicos/farmacología , Receptores Citoplasmáticos y Nucleares/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Ácidos y Sales Biliares/química , Ácidos Cólicos/química , Células HEK293 , Células Hep G2 , Humanos , Receptores Citoplasmáticos y Nucleares/genética , Receptores Acoplados a Proteínas G/genética , Activación Transcripcional/efectos de los fármacos
11.
Biomaterials ; 75: 47-57, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26480471

RESUMEN

A novel MRI blood-pool contrast agent (Gd-AAZTA-MADEC) has been compared with established blood pool agents for tumor contrast enhanced images and angiography. Synthesis, relaxometric properties, albumin binding affinity and pharmacokinetic profiles are reported. For in vivo studies, angiographic images and tumor contrast enhanced images were acquired on mice with benchtop 1T-MRI scanners and compared with MS-325, B22956/1 and B25716/1. The design of this contrast agent involved the elongation of the spacer between the targeting deoxycholic acid moiety and the Gd-AAZTA imaging reporting unit that drastically changed either the binding affinity to albumin (KA(HSA) = 8.3 × 10(5) M(-1)) and the hydration state of the Gd ion (q = 2) in comparison to the recently reported B25716/1. The very markedly high binding affinity towards mouse and human serum albumins resulted in peculiar pharmacokinetics and relaxometric properties. The NMRD profiles clearly indicated that maximum efficiency is attainable at magnetic field strength of 1 T. In vivo studies showed high enhancement of the vasculature and a prolonged accumulation inside tumor. The herein reported pre-clinical imaging studies show that a great benefit arises from the combination of a benchtop MRI scanner operating at 1 T and the albumin-binding Gd-AAZTA-MADEC complex, for pursuing enhanced angiography and improved characterization of tumor vascular microenvironment.


Asunto(s)
Ácidos Cólicos/química , Medios de Contraste/química , Complejos de Coordinación/química , Imagen de Acumulación Sanguínea de Compuerta , Imagen por Resonancia Magnética/instrumentación , Animales , Ácidos Cólicos/sangre , Ácidos Cólicos/síntesis química , Ácidos Cólicos/farmacocinética , Complejos de Coordinación/sangre , Complejos de Coordinación/síntesis química , Complejos de Coordinación/farmacocinética , Humanos , Angiografía por Resonancia Magnética , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Neoplasias/diagnóstico , Unión Proteica , Espectroscopía de Protones por Resonancia Magnética , Protones , Albúmina Sérica/metabolismo , Distribución Tisular , Agua
12.
Mol Biochem Parasitol ; 202(1): 22-8, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26341468

RESUMEN

Human and porcine cysticercosis is caused by the larval stage of the flatworm Taenia solium (Cestoda). The protein extracts of T. solium cysts are complex mixtures including cyst's and host proteins. Little is known about the influence of using different detergents in the efficiency of solubilization-extraction of these proteins, including relevant antigens. Here, we describe the use of CHAPS, ASB-14 and Triton X-100, alone or in combination in the extraction buffers, as a strategy to notably increase the recovery of proteins that are usually left aside in insoluble fractions of cysts. Using buffer with CHAPS alone, 315 protein spots were detected through 2D-PAGE. A total of 255 and 258 spots were detected using buffers with Triton X-100 or ASB-14, respectively. More protein spots were detected when detergents were combined, i.e., 2% CHAPS, 1% Triton X-100 and 1% ASB-14 allowed detection of up to 368 spots. Our results indicated that insoluble fractions of T. solium cysts were rich in antigens, including several glycoproteins that were sensitive to metaperiodate treatment. Host proteins, a common component in protein extracts of cysts, were present in larger amounts in soluble than insoluble fractions of cysts proteins. Finally, antigens present in the insoluble fraction were more appropriate as a source of antigens for diagnostic procedures.


Asunto(s)
Antígenos Helmínticos/aislamiento & purificación , Quistes/química , Detergentes/química , Taenia solium/química , Animales , Antígenos Helmínticos/inmunología , Betaína/análogos & derivados , Betaína/química , Tampones (Química) , Ácidos Cólicos/química , Quistes/inmunología , Quistes/parasitología , Electroforesis en Gel Bidimensional/métodos , Glicoproteínas/aislamiento & purificación , Humanos , Músculo Esquelético/parasitología , Porcinos , Taenia solium/inmunología , Teniasis/parasitología
13.
Curr Drug Targets ; 16(10): 1048-56, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26302794

RESUMEN

Eph-ephrin system is emerging as a new potential target in several diseases including cancer, diabetes, neurodegenerative diseases and inflammation. In the last decade, several efforts have been made to develop small molecule antagonists of Eph receptors. Both natural and synthetic compounds were discovered with (poly) phenol and steroidal derivatives on one side and the α1 agonist doxazosin, 2,5-dimethylpyrrol- 1-yl-benzoic acids and amino acid conjugates of lithocholic acid on the other. In the present paper we critically present available data for these compounds and discuss their potential usefulness as pharmacological tools or as candidates for a lead-optimization program.


Asunto(s)
Descubrimiento de Drogas/métodos , Efrinas/metabolismo , Preparaciones de Plantas/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Receptores de la Familia Eph/antagonistas & inhibidores , Bibliotecas de Moléculas Pequeñas/farmacología , Animales , Benzoatos/química , Benzoatos/farmacología , Ácidos Cólicos/química , Ácidos Cólicos/farmacología , Doxazosina/química , Doxazosina/farmacología , Humanos , Modelos Moleculares , Estructura Molecular , Preparaciones de Plantas/química , Unión Proteica , Mapeo de Interacción de Proteínas , Mapas de Interacción de Proteínas , Inhibidores de Proteínas Quinasas/química , Receptores de la Familia Eph/agonistas , Bibliotecas de Moléculas Pequeñas/química
14.
J Chem Inf Model ; 54(10): 2621-6, 2014 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-25289483

RESUMEN

The EPH receptor A2 (EPHA2) represents an attractive anticancer target. With the aim to identify novel EPHA2 receptor antagonists, a virtual screening campaign, combining shape-similarity and docking calculations, was conducted on a set of commercially available compounds. A combined score, taking into account both ligand- and structure-based results, was then used to identify the most promising candidates. Two compounds, selected among the best-ranked ones, were identified as EPHA2 receptor antagonists with micromolar affinity.


Asunto(s)
Antineoplásicos/química , Butiratos/química , Ácidos Cólicos/química , Descubrimiento de Drogas , Efrina-A1/antagonistas & inhibidores , Naftalenos/química , Inhibidores de Proteínas Quinasas/química , Receptor EphA2/antagonistas & inhibidores , Sitios de Unión , Efrina-A1/química , Ensayos Analíticos de Alto Rendimiento , Humanos , Ligandos , Simulación del Acoplamiento Molecular , Unión Proteica , Receptor EphA2/química , Relación Estructura-Actividad , Interfaz Usuario-Computador
15.
Acta Crystallogr D Biol Crystallogr ; 70(Pt 6): 1758-63, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24914985

RESUMEN

The carbonic anhydrases (CAs) are a family of mostly zinc metalloenzymes that catalyze the reversible hydration/dehydration of CO2 into bicarbonate and a proton. Human isoform CA II (HCA II) is abundant in the surface epithelial cells of the gastric mucosa, where it serves an important role in cytoprotection through bicarbonate secretion. Physiological inhibition of HCA II via the bile acids contributes to mucosal injury in ulcerogenic conditions. This study details the weak biophysical interactions associated with the binding of a primary bile acid, cholate, to HCA II. The X-ray crystallographic structure determined to 1.54 Šresolution revealed that cholate does not make any direct hydrogen-bond interactions with HCA II, but instead reconfigures the well ordered water network within the active site to promote indirect binding to the enzyme. Structural knowledge of the binding interactions of this nonsulfur-containing inhibitor with HCA II could provide the template design for high-affinity, isoform-specific therapeutic agents for a variety of diseases/pathological states, including cancer, glaucoma, epilepsy and osteoporosis.


Asunto(s)
Ácidos y Sales Biliares/química , Anhidrasa Carbónica II/química , Ácidos Cólicos/química , Secuencia de Aminoácidos , Cristalografía por Rayos X , Humanos , Modelos Moleculares , Datos de Secuencia Molecular
16.
Peptides ; 55: 79-84, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24582609

RESUMEN

The zwitterionic detergent CHAPS was used to solubilize the human mu-opioid receptor (hMOR) from SH-SY5Y neuroblastoma cells and recombinant hMOR-CHO (CHO-T7-hMOR) and hMOR-SH-SY5Y (SH-SY5Y-T7-hMOR) cell membranes. Agonist stimulation and G-protein activation by the mu-selective opioid agonist DAMGO ([D-Ala2, N-MePhe4, Gly-ol]-enkephalin) were recovered after removing of CHAPS after polyethylene glycol (PEG) precipitation. Binding assays show that hMOR solubilized and reconstituted this way was functional and able to interact with both agonist peptides and with G-protein. The effective solubilization and reconstitution of hMOR from mammalian cells, without truncation and extensive modification, represent an essential step toward the purification of a receptor bearing important post-translational modifications.


Asunto(s)
Receptores Opioides mu/química , Animales , Células CHO , Línea Celular Tumoral , Ácidos Cólicos/química , Cricetulus , Detergentes/química , Diprenorfina/química , Encefalina Ala(2)-MeFe(4)-Gli(5)/química , Guanosina 5'-O-(3-Tiotrifosfato)/química , Humanos , Ligandos , Antagonistas de Narcóticos/química , Polietilenglicoles/química , Unión Proteica , Replegamiento Proteico , Receptores Opioides mu/agonistas , Receptores Opioides mu/biosíntesis , Solubilidad
17.
Anal Chim Acta ; 800: 36-42, 2013 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-24120165

RESUMEN

The nutritional and cancer-protective properties of the oil extracted mechanically from the ripe fruits of Olea europaea trees are attracting constantly more attention worldwide. The preparation of high-quality protein samples from plant tissues for proteomic analysis poses many challenging problems. In this study we employed a proteomic platform based on two different extraction methods, SDS and CHAPS based protocols, followed by two precipitation protocols, TCA/acetone and MeOH precipitation, in order to increase the final number of identified proteins. The use of advanced MS techniques in combination with the Swissprot and NCBI Viridiplantae databases and TAIR10 Arabidopsis database allowed us to identify 1265 proteins, of which 22 belong to O. europaea. The application of this proteomic platform for protein extraction and identification will be useful also for other proteomic studies on recalcitrant plant/fruit tissues.


Asunto(s)
Tecnología de Alimentos/métodos , Olea/química , Proteínas de Plantas/análisis , Proteómica , Espectrometría de Masas en Tándem , Acetona/química , Ácidos Cólicos/química , Cromatografía Líquida de Alta Presión , Bases de Datos de Proteínas , Tecnología de Alimentos/instrumentación , Frutas/química , Frutas/metabolismo , Metanol/química , Nanotecnología , Olea/metabolismo , Dodecil Sulfato de Sodio/química , Ácido Tricloroacético/química
18.
Molecules ; 18(10): 13043-60, 2013 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-24152675

RESUMEN

The Eph-ephrin system plays a critical role in tumor growth and vascular functions during carcinogenesis. We had previously identified cholanic acid as a competitive and reversible EphA2 antagonist able to disrupt EphA2-ephrinA1 interaction and to inhibit EphA2 activation in prostate cancer cells. Herein, we report the synthesis and biological evaluation of a set of cholanic acid derivatives obtained by conjugation of its carboxyl group with a panel of naturally occurring amino acids with the aim to improve EphA2 receptor inhibition. Structure-activity relationships indicate that conjugation of cholanic acid with linear amino acids of small size leads to effective EphA2 antagonists whereas the introduction of aromatic amino acids reduces the potency in displacement studies. The b-alanine derivative 4 was able to disrupt EphA2-ephrinA1 interaction in the micromolar range and to dose-dependently inhibit EphA2 activation on PC3 cells. These findings may help the design of novel EphA2 antagonists active on cancer cell lines.


Asunto(s)
Ácidos Cólicos/farmacología , Receptor EphA2/antagonistas & inhibidores , Sitios de Unión , Línea Celular Tumoral , Ácidos Cólicos/síntesis química , Ácidos Cólicos/química , Humanos , Enlace de Hidrógeno , Concentración 50 Inhibidora , Simulación del Acoplamiento Molecular , Fosforilación , Unión Proteica , Procesamiento Proteico-Postraduccional/efectos de los fármacos , Estructura Secundaria de Proteína , Receptor EphA1/antagonistas & inhibidores , Receptor EphA1/química , Receptor EphA1/metabolismo , Receptor EphA2/química , Receptor EphA2/metabolismo , Relación Estructura-Actividad
19.
J Phys Chem B ; 117(31): 9248-57, 2013 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-23844889

RESUMEN

Biocompatible molecules that undergo self-assembly are of high importance in biological and medical applications of nanoscience. Peptides and bile acids are among the most investigated due to their ability to self-organize into many different, often stimuli-sensitive, supramolecular structures. With the aim of preparing molecules mixing the aggregation properties of bile acid and amino acid-based molecules, we report on the synthesis and self-association behavior of two diastereomers obtained by substituting a hydroxyl group of cholic acid with a l-phenylalanine residue. The obtained molecules are amphoteric, and we demonstrate that they show a pH-dependent self-assembly. Both molecules aggregate in globular micelles at high pH, whereas they form tubular superstructures under acid conditions. Unusual narrow nanotubes with outer and inner cross-section diameters of about 6 and 3 nm are formed by the derivatives. The diasteroisomer with α orientation of the substituent forms in addition a wider tubule (17 nm cross-section diameter). The ability to pack in supramolecular tubules is explained in terms of a wedge-shaped bola-form structure of the derivatives. Parallel or antiparallel face-to-face dimers are hypothesized as fundamental building blocks for the formation of the narrow and wide nanotubes, respectively.


Asunto(s)
Ácidos y Sales Biliares/química , Ácidos Cólicos/química , Péptidos/química , Fenilalanina/química , Dicroismo Circular , Concentración de Iones de Hidrógeno , Micelas , Microscopía de Fuerza Atómica , Péptidos/metabolismo , Tensión Superficial , Temperatura
20.
Steroids ; 78(9): 832-44, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23707574

RESUMEN

A series of final six propanoyloxy derivatives of 5ß-cholan-24-oic acid (tridecafluoroctylsulfanyl- and tridecafluoroctylsulfinylethoxycarbonylpropanoyloxy derivatives) as potential drug absorption promoters (skin penetration enhancers, intestinal absorption promoters) was generated by multistep synthesis. Structure confirmation of all generated compounds was accomplished by (1)H NMR, (13)C NMR, IR and MS spectroscopy methods. All the prepared compounds were analyzed using RP-TLC, and their lipophilicity (RM) was determined. The hydrophobicity (log P), solubility (logS), polar surface area (PSA) and molar volume (MV) of the studied compounds were also calculated. All the target compounds were tested for their in vitro transdermal penetration effect and as potential intestinal absorption enhancers. The cytotoxicity of all the evaluated compounds was evaluated against normal human skin fibroblast cells. Their anti-proliferative activity was also assessed against human cancer cell lines: T-lymphoblastic leukaemia cell line and breast adenocarcinoma cell line. One compound showed high selective cytotoxicity against human skin fibroblast cells and another compound possessed high cytotoxicity against breast adenocarcinoma cell line and skin fibroblast cells. Only one compound expressed anti-proliferative effect on leukaemia and breast adenocarcinoma cells without affecting the growth of normal cells, which should be promising in potential development of new drugs. Most of the target compounds showed minimal anti-proliferative activity (IC50>37µM), indicating they would have moderate cytotoxicity when administered as chemical absorption modifiers. The relationships between the lipophilicity/polarity and the chemical structure of the studied compounds as well as the relationships between their chemical structure and penetration enhancement effect are discussed in this article.


Asunto(s)
Ácidos Cólicos/química , Excipientes/síntesis química , Hidrocarburos Fluorados/síntesis química , Propionatos/síntesis química , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Excipientes/metabolismo , Excipientes/toxicidad , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Humanos , Hidrocarburos Fluorados/metabolismo , Hidrocarburos Fluorados/toxicidad , Interacciones Hidrofóbicas e Hidrofílicas , Absorción Intestinal , Células MCF-7 , Membranas Artificiales , Permeabilidad , Propionatos/metabolismo , Propionatos/toxicidad , Absorción Cutánea , Solubilidad
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