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1.
Int J Biol Macromol ; 195: 12-21, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34890634

RESUMEN

In order to better utilize the citrus pectin (CP) resource, the crude citrus pectin (CCP), obtained from the citrus fruit canning processing waste water, was purified by cellulose DEAE-52 column, providing neutral polysaccharide CP0 and two acidic polysaccharides (CP1 and CP3). CP1 had the highest yield among the three fractions, being 44.29%. The chemical composition, structure and morphology of these pectin components were analyzed. Monosaccharide composition analysis revealed that arabinose was the most abundant composition in these pectin samples. CCP, CP1 and CP3 were mainly composed of rhamnogalacturonan-I (RG-I) regions. Compared with CP3, CCP and CP1 had longer side chains, which are mainly consisted of arabinose. FT-IR and NMR analysis indicated that α-type glycosidic bonds are the main linkage in the four pectin components. These CP samples were found to possess different conformation, but no triple-helical conformation was observed in all these CP fractions. Scanning electron microscopy revealed that CCP, CP1 and CP3 all had irregular sheet-like structures and partly porous structures. The four pectin components showed the characteristics of non-Newtonian fluids and possessed good viscoelasticity. Due to these properties, the pectin might have potential application in food industry as food thickening agent.


Asunto(s)
Arabinosa/aislamiento & purificación , Citrus/química , Glicósidos/aislamiento & purificación , Pectinas/química , Pectinas/aislamiento & purificación , Secuencia de Carbohidratos , Cromatografía DEAE-Celulosa , Espectroscopía de Resonancia Magnética , Microscopía de Fuerza Atómica , Microscopía Electrónica de Rastreo , Espectroscopía Infrarroja por Transformada de Fourier
2.
Planta Med ; 85(13): 1098-1106, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31250410

RESUMEN

In previous studies, crude Houttuynia cordata polysaccharides showed beneficial effects on acute lung injury in vivo, a syndrome in which anti-complementary activities played an important role. Anti-complementary activity-guided fractionation of H. cordata polysaccharides led to the isolation of two highly branched homogeneous polysaccharides, HC-PS1 and HC-PS3, with a molecular weight of 274 530 and 216 384 Da, respectively. The polysaccharides were purified by chromatography on DEAE-cellulose and Superdex columns. Their structural characterization was performed by IR, GC-MS, methylation, NMR, and SEM analysis. Both HC-PS1 and HC-PS3 are composed of eight types of monosaccharides, including rhamnose, arabinose, mannose, glucose, glucuronic acid, galactose, galacturonic acid, and xylose. The main linkages of the sugar residues in HC-PS1 include terminal Rhap, terminal and 1,5-linked Araf; 1,3,6-linked and 1,4,6-linked Manp; terminal, 1,4-linked, 1,3-linked, 1,3,6-linked and 1,4,6-linked and 1,3,4,6-linked Glcp; and terminal, 1,4-linked and 1,6-linked Galp. The main monosaccharide linkages in HC-PS3 are similar to that of HC-PS1, except the additional 1,3,4-linked Manp and the absence of 1,3,6-linked Glcp. HC-PS1 and HC-PS3 were found to inhibit complement activation through both the classical and alternative pathways with 50% inhibition concentrations of 0.272 - 0.318 mg/mL without interfering with the coagulation system. Preliminary mechanism studies indicated that both HC-PS1 and HC-PS3 inhibited the activation of the complement system by interacting with C2, C4, and C5. The results suggest that HC-PS1 and HC-PS3 could be valuable for the treatment of diseases associated with the excessive activation of the complement system.


Asunto(s)
Proteínas del Sistema Complemento/efectos de los fármacos , Houttuynia/química , Cromatografía DEAE-Celulosa , Activación de Complemento/efectos de los fármacos , Humanos , Espectroscopía de Resonancia Magnética , Polisacáridos/química , Polisacáridos/farmacología , Espectroscopía Infrarroja por Transformada de Fourier
3.
Molecules ; 23(10)2018 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-30248961

RESUMEN

Modern studies have shown that pollen has a certain role in the treatment of prostate-related diseases. In the present study, pollen polysaccharides from Chinese wolfberry (WPPs) were extracted by hot-water extraction and ethanol precipitation, further purified by chromatography on a DEAE-cellulose column and Sephadex G-100 column. Homogeneous polysaccharide CF1 of WPPS was obtained, the molecular weight of which was estimated to be 1540.10 ± 48.78 kDa by HPGPC-ELSD. HPLC with PMP derivatization analysis indicated that the monosaccharide compositions of CF1 were mannose, glucuronic acid, galacturonic acid, xylose, galactose, arabinose, and trehalose, in a molar ratio of 0.68:0.59:0.27:0.24:0.22:0.67:0.08. The antitumor effects of CF1 upon MTT, Tunel assay and flow cytometry assay were investigated in vitro. The results showed that CF1 exhibited a dose-dependent antiproliferative effect, with an IC50 value of 374.11 µg/mL against DU145 prostate cancer cells. Tunel assay and flow cytometry assay showed that the antitumor activity of CF1 was related to apoptosis in vitro. The present study suggested that the CF1 of WPPs might be a potential source of antitumor functional food or agent.


Asunto(s)
Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Lycium/química , Polisacáridos/química , Polisacáridos/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cromatografía DEAE-Celulosa , Dextranos , Relación Dosis-Respuesta a Droga , Humanos , Masculino , Extractos Vegetales/química , Extractos Vegetales/farmacología , Polen/química , Neoplasias de la Próstata/tratamiento farmacológico
4.
Molecules ; 23(8)2018 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-30065217

RESUMEN

Polysaccharides from Ascophyllum nodosum (AnPS) were extracted and purified via an optimized protocol. The optimal extraction conditions were as follows: extraction time of 4.3 h, extraction temperature of 84 °C and ratio (v/w, mL/g) of extraction solvent (water) to raw material of 27. The resulting yield was 9.15 ± 0.23% of crude AnPS. Two fractions, named AnP1-1 and AnP2-1 with molecular weights of 165.92 KDa and 370.68 KDa, were separated from the crude AnPS by chromatography in DEAE Sepharose Fast Flow and Sephacryl S-300, respectively. AnP1-1 was composed of mannose, ribose, glucuronic acid, glucose and fucose, and AnP2-1 was composed of mannose, glucuronic acid, galactose and fucose. AnPS, AnP1-1 and AnP2-1 exhibited high scavenging activities against ABTS radical and superoxide radical, and showed protective effect on H2O2-induced oxidative injury in RAW264.7 cells. Furthermore, the immunostimulatory activities of AnP1-1 and AnP2-1 were evaluated by Caco-2 cells, the results showed both AnP1-1 and AnP2-1 could significantly promote the production of immune reactive molecules such as interleukin (IL)-8, IL-1ß, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α. Therefore, the results suggest that AnPS and its two fractions may be explored as a potential functional food supplement.


Asunto(s)
Adyuvantes Inmunológicos/aislamiento & purificación , Antioxidantes/aislamiento & purificación , Ascophyllum/química , Extracción Líquido-Líquido/métodos , Polisacáridos/aislamiento & purificación , Adyuvantes Inmunológicos/química , Adyuvantes Inmunológicos/farmacología , Animales , Antioxidantes/química , Antioxidantes/farmacología , Células CACO-2 , Supervivencia Celular/efectos de los fármacos , Cromatografía DEAE-Celulosa , Fucosa/química , Fucosa/aislamiento & purificación , Galactosa/química , Galactosa/aislamiento & purificación , Ácido Glucurónico/química , Ácido Glucurónico/aislamiento & purificación , Humanos , Peróxido de Hidrógeno/antagonistas & inhibidores , Peróxido de Hidrógeno/farmacología , Interferón gamma/biosíntesis , Interferón gamma/inmunología , Interleucina-1beta/biosíntesis , Interleucina-1beta/inmunología , Interleucina-8/biosíntesis , Interleucina-8/inmunología , Manosa/química , Manosa/aislamiento & purificación , Ratones , Polisacáridos/química , Polisacáridos/farmacología , Células RAW 264.7 , Solventes/química , Sulfatos/química , Factor de Necrosis Tumoral alfa/biosíntesis , Factor de Necrosis Tumoral alfa/inmunología , Agua/química
5.
Molecules ; 22(2)2017 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-28216596

RESUMEN

Rhizome of Ligusticum chuanxiong is an effective medical plant, which has been extensively applied for centuries in migraine and cardiovascular diseases treatment in China. Polysaccharides from this plant have been shown to have interesting bioactivities, but previous studies have only been performed on the neutral polysaccharides. In this study, LCP-I-I, a pectic polysaccharide fraction, was obtained from the 100 °C water extracts of L. chuangxiong rhizomes and purified by diethylaminethyl (DEAE) sepharose anion exchange chromatography and gel filtration. Monosaccharide analysis and linkage determination in addition to Fourier transform infrared (FT-IR) spectrometer and Nuclear magnetic resonance (NMR) spectrum, indicated that LCP-I-I is a typical pectic polysaccharide, with homo-galacturonan and rhamnogalacturonan type I regions and arabinogalactan type I and type II (AG-I/AG-II) side chains. LCP-I-I exhibited potent complement fixation activity, ICH50 of 26.3 ± 2.2 µg/mL, and thus has potential as a natural immunomodulator.


Asunto(s)
Activación de Complemento , Medicamentos Herbarios Chinos/química , Ligusticum/química , Pectinas/química , Cromatografía DEAE-Celulosa , Cromatografía de Gases , Pruebas de Fijación del Complemento , Galactanos/química , Cromatografía de Gases y Espectrometría de Masas , Espectroscopía de Resonancia Magnética , Peso Molecular , Monosacáridos/química , Plantas Medicinales/química , Rizoma/química , Espectroscopía Infrarroja por Transformada de Fourier
6.
BMC Biochem ; 15: 15, 2014 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-25065975

RESUMEN

BACKGROUND: Urease, one of the highly efficient known enzymes, catalyzes the hydrolysis of urea into ammonia and carbon dioxide. The present study aimed to extract urease from pea seeds (Pisum Sativum L). The enzyme was then purified in three consequence steps: acetone precipitation, DEAE-cellulose ion-exchange chromatography, and gel filtration chromatography (Sephacryl S-200 column). RESULTS: The purification fold was 12.85 with a yield of 40%. The molecular weight of the isolated urease was estimated by chromatography to be 269,000 Daltons. Maximum urease activity (190 U/g) was achieved at the optimum conditions of 40°C and pH of 7.5 after 5 min of incubation. The kinetic parameters, Km and Vmax, were estimated by Lineweaver-Burk fits and found to be 500 mM and 333.3 U/g, respectively. The thermodynamic constants of activation, ΔH, Ea, and ΔS, were determined using Arrhenius plot and found to be 21.20 kJ/mol, 23.7 kJ/mol, and 1.18 kJ/mol/K, respectively. CONCLUSIONS: Urease was purified from germinating Pisum Sativum L. seeds. The purification fold, yield, and molecular weight were determined. The effects of pH, concentration of enzyme, temperature, concentration of substrate, and storage period on urease activity were examined. This may provide an insight on the various aspects of the property of the enzyme. The significance of extracting urease from different sources could play a good role in understanding the metabolism of urea in plants.


Asunto(s)
Bioquímica/métodos , Pisum sativum/enzimología , Proteínas de Plantas/aislamiento & purificación , Urea/metabolismo , Ureasa/aislamiento & purificación , Resinas Acrílicas , Precipitación Química , Cromatografía DEAE-Celulosa , Cromatografía en Gel , Germinación , Hidrólisis , Peso Molecular , Extractos Vegetales , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Semillas , Termodinámica , Ureasa/química , Ureasa/metabolismo
7.
Carbohydr Polym ; 106: 247-54, 2014 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-24721075

RESUMEN

Dendrobium huoshanense, an important food material, has been used to make teas and soups in the folk of China for centuries. In the present study, an antiglycation polysaccharide DHPD2 with molecular weight of 8.09 × 10(6)Da was extracted from the protocorm-like bodies of D. huoshanense. The backbone of DHPD2 contained (1→5)-linked α-l-Araf, (1→6)-linked α-d-Glcp, (1→6)-linked ß-d-Glcp, (1→4)-linked ß-d-Glcp, (1→3,6)-linked ß-d-Galp and (1→6)-linked ß-d-Galp, with the branches of terminal α-d-Xlyp and ß-d-Manp. DHPD2 was further modified using chlorosulfonic acid-pyridine method, giving two sulfated derivatives with the substitution degree of 0.475 and 0.940. The appearance of two new characteristic absorption bands at near 1250 and 822cm(-1) in FT-IR spectra revealed the success of sulfation occurred to DHPD2. Moreover, the sulfated derivatives exhibited stronger inhibitory abilities on protein glycation than those of DHPD2. NMR analysis disclosed that the sulfation on C2 and C6 of sugar residues was beneficial to enhance this activity.


Asunto(s)
Dendrobium/química , Productos Finales de Glicación Avanzada/antagonistas & inhibidores , Plantas Comestibles/química , Polisacáridos/aislamiento & purificación , Conformación de Carbohidratos , Secuencia de Carbohidratos , Cromatografía DEAE-Celulosa , Carbohidratos de la Dieta/metabolismo , Glicosilación , Espectroscopía de Resonancia Magnética , Datos de Secuencia Molecular , Peso Molecular , Polisacáridos/química , Piridinas/farmacología , Albúmina Sérica Bovina/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Relación Estructura-Actividad , Sulfatos/metabolismo , Ácidos Sulfónicos/farmacología
8.
Protein Pept Lett ; 19(11): 1205-11, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22512653

RESUMEN

Pectin methylesterase (PME) (3.1.1.11) is the pectin degrading enzyme which catalyses the hydrolysis of pectin methylester group, resulting in de-esterification. PME is widely distributed in plants, fungi, yeast and bacteria. In the present study, PME was extracted from tomato by using 8.8% NaCl (4°C). The crude enzyme precipitated with 60% ammonium sulphate resulted in 1.02 fold purification of the enzyme. The purification was done by ion exchange chromatography using DEAE-Cellulose column. This resulted in 1.82 fold purification of the enzyme. The molecular weight of purified enzyme was determined by SDS-PAGE which was found to be 34.0 kDa. During characterization of the purified enzyme, the maximum activity was found at temperature 50°C, pH 6.5, reaction time 45 min. Citrus pectin was the best substrate for maximum enzyme activity. The enzyme did not require any metal ion to express its activity, enzyme was found to be very stable at 4°C and at 50°C the enzyme was stable upto 2 h as it retained 70% of its activity. The K(m) and V(max) values of the enzyme were found to be 0.115 mg/ml and 1.03 µmol/ml/min. PME enhanced the pectin degradation process in apple juice clarification in combination with polygalacturonase and increased %T(650) from 1.7% to 5.6%.


Asunto(s)
Hidrolasas de Éster Carboxílico/aislamiento & purificación , Solanum lycopersicum/enzimología , Amilopectina/metabolismo , Bebidas , Hidrolasas de Éster Carboxílico/química , Hidrolasas de Éster Carboxílico/metabolismo , Precipitación Química , Cromatografía DEAE-Celulosa , Electroforesis en Gel de Poliacrilamida , Estabilidad de Enzimas , Concentración de Iones de Hidrógeno , Modelos Lineales , Solanum lycopersicum/química , Malus , Peso Molecular , Pectinas/metabolismo , Especificidad por Sustrato , Temperatura
9.
Indian J Biochem Biophys ; 49(1): 42-8, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22435143

RESUMEN

Mn-peroxidase (MnP), a biotechnologically important enzyme was purified for the first time from a plant source Musa paradisiaca (banana) stem, which is an agro-waste easily available after harvest of banana fruits. MnP was earlier purified only from the fungal sources. The enzyme was purified from stem juice by ultrafiltration and anion-exchange column chromatography on diethylamino ethylcellulose with 8-fold purification and purification yield of 65%. The enzyme gave a single protein band in SDS-PAGE corresponding to molecular mass 43 kDa. The Native-PAGE of the enzyme also gave a single protein band, confirming the purity of the enzyme. The UV/VIS spectrum of the purified enzyme differed from the other heme peroxidases, as the Soret band was shifted towards lower wavelength and the enzyme had an intense absorption band around 250 nm. The K(m) values using MnSO4 and H2O2 as the substrates of the purified enzyme were 21.0 and 9.5 microM, respectively. The calculated k(cat) value of the purified enzyme using Mn(II) as the substrate in 50 mM lactate buffer (pH 4.5) at 25 degrees C was 6.7s(-1), giving a k(cat)/K(m) value of 0.32 microM(-1)s(-1). The k(cat) value for the MnP-catalyzed reaction was found to be dependent of the Mn(III) chelator molecules malonate, lactate and oxalate, indicating that the enzyme oxidized chelated Mn(II) to Mn(III). The pH and temperature optima of the enzyme were 4.5 and 25 degrees C, respectively. The enzyme in combination with H2O2 liberated bromine and iodine in presence of KBr and KI respectively. All these enzymatic characteristics were similar to those of fungal MnP. The enzyme has the potential as a green brominating and iodinating agent in combination with KBr/KI and H2O2.


Asunto(s)
Halogenación , Musa/enzimología , Peroxidasas/química , Peroxidasas/aislamiento & purificación , Catálisis , Cromatografía DEAE-Celulosa , Estabilidad de Enzimas , Concentración de Iones de Hidrógeno , Cinética , Peso Molecular , Oxidación-Reducción , Peroxidasas/farmacocinética , Extractos Vegetales/aislamiento & purificación , Proteínas de Plantas/química , Proteínas de Plantas/aislamiento & purificación , Proteínas de Plantas/farmacocinética , Tallos de la Planta/enzimología , Espectrofotometría Ultravioleta , Especificidad por Sustrato , Temperatura , Ultrafiltración
10.
Blood Coagul Fibrinolysis ; 22(8): 631-6, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21934490

RESUMEN

Pollen Typhae is the traditional Chinese herbal medicine widely used to treat the hemorrhagic diseases both by external and oral application. The present study examines the hemostatic properties and its components of Pollen Typhae. Pollen extract significantly reduced prothrombin time (PT), activated partial prothrombin time (APTT) and recalcification time. Pollen extract directly activated factor XII in the coagulation cascade. Acidic polysaccharide in the pollen that adsorbed to the diethylaminoethyl (DEAE) column was the causative agent of factor XII activation. These results suggested that an electronegative charge attributed to an acidic polysaccharide in the pollen extract contributed to the hemostatic activity. We then examined the hemostatic activity of administered pollen extract in the mouse tail bleeding model. Tail bleeding was significantly decreased after oral administration of the pollen extract, whereas the acidic polysaccharide fraction did not affect the duration of tail bleeding. These results suggest that the oral anticoagulant effect of Pollen Typhae is attributed to compounds other than acidic polysaccharides. We concluded that the activation of the intrinsic coagulation pathway by the acidic polysaccharide contributes to the external hemostatic property of Pollen Typhae, and the action of components such as flavonoids that possess anticoagulant activity are causative agent when orally administered.


Asunto(s)
Anticoagulantes/farmacología , Coagulación Sanguínea/efectos de los fármacos , Hemorragia/tratamiento farmacológico , Medicina Tradicional China/métodos , Fitoterapia/métodos , Extractos Vegetales/farmacología , Polen/química , Typhaceae/química , Animales , Anticoagulantes/química , Cromatografía DEAE-Celulosa , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/farmacología , Factor XII/agonistas , Factor XII/metabolismo , Flavonoides/química , Flavonoides/farmacología , Hemorragia/sangre , Humanos , Masculino , Ratones , Tiempo de Tromboplastina Parcial , Extractos Vegetales/química , Polisacáridos/química , Polisacáridos/farmacología , Tiempo de Protrombina , Electricidad Estática , Agua
11.
Molecules ; 15(8): 5818-30, 2010 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-20736909

RESUMEN

An alpha-glucan was isolated from the culinary medicinal mushroom A. bisporus by hot water extraction, ethanol precipitation and DEAE-cellulose chromatography. The resulting material showed a single HMW peak excluded from a Sephadex G50 column that could completely be degraded by alpha-amylase treatment. After heating in 1% SDS a small additional peak of low MW eluted from the G50 column. The monosaccharide composition of the main peak was evaluated by HPLC, and was found to consist of a majority of glucose (97.6%), and a minor proportion of galactose (2.4%). Methylation analysis and degradation by alpha-amylase indicated the presence of an alpha-glucan with a main chain consisting of (1(R)4)-linked units, substituted at O-6 by alpha-D-glucopyranose single-units in the relation 1:8. Mono- (13C-, 1H-NMR) and bidimensional [1H (obs.),13C-HSQC] spectroscopy analysis confirmed the alpha-configuration of the Glcp residues by low frequency resonances of C-1 at delta 100.6, 100.2, and 98.8 ppm and H-1 high field ones at delta 5.06, 5.11, and 4.74 ppm. The DEPT-13C-NMR allowed assigning the non-substituted and O-substituted -CH(2) signals at delta 60.3/60.8 and 66.2 ppm, respectively. Other assignments were attributed to C-2, C-3, C-4, C-5 and C-6 of the non-reducing ends at delta 71.8; 72.8; 70.0; 71.3 and 60.3/60.8 ppm, respectively. The minor proportion of galactose that was demonstrated was probably derived from a complex between the alpha-glucan and a low molecular weight galactan.


Asunto(s)
Agaricus/metabolismo , Galactanos/metabolismo , Glucanos/metabolismo , Plantas Medicinales/química , Conformación de Carbohidratos , Cromatografía DEAE-Celulosa , Cromatografía Líquida de Alta Presión , Galactanos/química , Glucanos/química , Glucanos/aislamiento & purificación , Hidrólisis , Espectroscopía de Resonancia Magnética , Metilación , Peso Molecular , alfa-Amilasas/metabolismo
12.
Toxicon ; 55(1): 118-25, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19619571

RESUMEN

Cyanea nozakii Kishinouye, a jellyfish widely distributed in coastal areas of China, has garnered attention because of its stinging capacity and the resulting public health hazard. We used a recently developed technique to extract jellyfish venom from nematocysts; the present study investigates the lethality of C. nozakii venom. The nematocyst contents were extremely toxic to the grass carp, Ctenopharyngodon idellus, producing typical neurotoxin toxicity. The ID(50) was about 0.6microg protein/g fish. Toxin samples were stable when kept at -80( degrees )C, but after 48h, an 80% decline in lethality occurred at -20( degrees )C. Poor stability of the venom was observed within the range of 65-80( degrees )C and at pH 3.5. The venom was hydrolyzed by a proteolytic enzyme, trypsin. Fractionation of the venom yielded two protein bands with molecular weights of 60kDa and 50kDa. Our results provide the first evidence that C. nozakii produces lethal toxins. These characteristics highlight the need for the isolation and molecular characterization of new active toxins in C. nozakii.


Asunto(s)
Venenos de Cnidarios/química , Venenos de Cnidarios/toxicidad , Proteínas/química , Proteínas/toxicidad , Escifozoos/química , Animales , Bioensayo , Carpas , China , Cromatografía DEAE-Celulosa , Cromatografía en Gel , Venenos de Cnidarios/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Electroforesis en Gel de Poliacrilamida , Concentración de Iones de Hidrógeno , Dosificación Letal Mediana , Microscopía Electrónica de Rastreo , Peso Molecular , Océano Pacífico , Proteínas/aislamiento & purificación , Escifozoos/anatomía & histología , Escifozoos/ultraestructura , Temperatura , Factores de Tiempo
13.
Bioresour Technol ; 100(6): 2095-7, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19056259

RESUMEN

The tolerant-selenium exopolysaccharide-producing bacterial strain Enterobacter cloacae Z0206 was batch cultured in PDA medium containing optimal concentration of sodium selenite. Selenium was accumulated efficiently in Enterobacter cloacae Z0206 during cultivation with selenium. Inorganic selenite could be transformed into organic forms. Selenium-enriched exopolysaccharide (Se-ECZ-EPS-1) was purified from the fermentation liquid. Selenium content of Se-ECZ-EPS-1 was 12.962microg/g. Se-ECZ-EPS-1 with Mw of 29,300Ka was composed of Glc, Gal and Mann with molar ratio of 8.530:0.061:0.706. Administration of Se-ECZ-EPS-1 to cyclophosphamide (CP)-exposed animals resulted in improvement of cellular and humoral immune responses. These findings indicated that Se-ECZ-EPS-1 may act as potent immunomodulatory agents.


Asunto(s)
Enterobacter cloacae/metabolismo , Factores Inmunológicos/farmacología , Polisacáridos/farmacología , Selenio/química , Animales , Biotransformación , Cromatografía DEAE-Celulosa , Cromatografía Líquida de Alta Presión , Factores Inmunológicos/química , Factores Inmunológicos/metabolismo , Masculino , Ratones , Ratones Endogámicos ICR , Microscopía de Fuerza Atómica , Tamaño de los Órganos/efectos de los fármacos , Polisacáridos/biosíntesis , Polisacáridos/química , Espectroscopía Infrarroja por Transformada de Fourier , Bazo/efectos de los fármacos , Bazo/inmunología , Timo/efectos de los fármacos , Timo/inmunología
14.
Assay Drug Dev Technol ; 6(6): 803-10, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19090689

RESUMEN

Human peroxisome proliferator-activated receptors (hPPARs) are ligand-activated transcription factors and are the target for the treatment of many diseases. Screening of their ligands is mainly based on assays of ligand binding to the ligand binding domain (LBD) of hPPARs.However, such assays are difficult because of the preparation of hPPARs LBD. In order to yield functional hPPARs LBD for screening ligands, hPPARs LBD was fused with maltose-binding protein(MBP) using the pMAL-p2x expression system through the gene engineering technique. The radioligand binding assay showed that MBP did not affect ligand binding with hPPARs LBD in the fusion proteins, which means that MBP-hPPARs LBD can be used instead of hPPARs LBD in ligand screening work. The results show that the new strategy using MBP as a fusion tag for preparing hPPARs LBD for screening ligands is a convenient and reliable method. It may be used to easily obtain the other nuclear receptors.


Asunto(s)
Proteínas Portadoras/metabolismo , Evaluación Preclínica de Medicamentos/métodos , Proteínas de Escherichia coli/metabolismo , Ligandos , Receptores Activados del Proliferador del Peroxisoma/metabolismo , Amilosa/química , Ácido Araquidónico/farmacología , Sitios de Unión/efectos de los fármacos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Proteínas Portadoras/aislamiento & purificación , Cromatografía de Afinidad , Cromatografía DEAE-Celulosa , ADN Complementario/síntesis química , ADN Complementario/genética , Electroforesis en Gel de Poliacrilamida , Escherichia coli/enzimología , Factor Xa/química , Factor Xa/metabolismo , Humanos , Isopropil Tiogalactósido/farmacología , Masculino , Proteínas de Unión a Maltosa , Receptores Activados del Proliferador del Peroxisoma/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/aislamiento & purificación , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Transcripción
15.
Assay Drug Dev Technol ; 2(6): 621-8, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15674020

RESUMEN

High-throughput screening (HTS) is a powerful approach for the discovery of potential and effective drugs from a number of candidates. The dynamics of tubulin assembly and disassembly in vitro are an important target for the screening of anti-tumor agents. However, previously described methods are not amenable for HTS. In this paper, we compared preparation methods of tubulin and suggest a combination method, i.e., one cycle of assembly and disassembly following ion-exchange chromatography using high concentrations of glutamate to increase the recovery of tubulin with high purity. The resultant highly purified microtubule-associated proteins-free tubulin in high glutamate solution was directly employed in tubulin polymerization assays. Our results indicate that the system is feasible and practicable as a model for HTS for microtubule-stabilizing agents.


Asunto(s)
Ácido Glutámico/química , Microtúbulos/efectos de los fármacos , Tubulina (Proteína)/química , Cromatografía DEAE-Celulosa , Técnicas Químicas Combinatorias , Evaluación Preclínica de Medicamentos , Guanosina Trifosfato/química , Microscopía Electrónica , Polímeros/síntesis química , Tubulina (Proteína)/aislamiento & purificación
16.
Appl Biochem Biotechnol ; 105 -108: 677-87, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12721447

RESUMEN

The objective of this study was to obtain purer acid phosphatases than produced by prior art by operating under conditions that improve the final product. The study features are the use of a mild nonionic detergent, 40-80% saturation with (NH4)2SOm4, maintained at low temperature to remove impurity, and the use of chromatografic columns to concentrate the acid phosphatase and remove non-acid phosphatase proteins with lower or higher molecular weights. Acid phosphatase was isolated and purified from garlic seedlings by a streamline method without the use of proteolytic and lipolytic enzymes, butanol, or other organic solvents. Grown garlic seedlings of 10- 15 cm height were homogenized with 0.1 M acetate buffer containing 0.1 M NaCl and 0.1% Triton X-100. After homogenization, the supernatant was filtered with paper filters. Filtrated supernatant was cooled to 4 degrees C, followed by a threestep fractionation of the proteins with ammonium sulfate. The crude enzyme was isolated as a green precipitate that was dissolved in a small amount of 0.1 M acetate buffer containing 0.1 M NaCl and 0.1% Triton X-100. Garlic seedling acid phosphatase was purified with ion-exchange chromatography (DEAE cellulose). The column was equilibrated with 0.1 M acetate buffer. Acid phosphatase was purified 40-fold from the starting material. The specific activity of the pure enzyme was 168 U/mg. A variety of stability and activity profiles were determined for the purified garlic seedling acid phosphatase: optimum pH, optimum temperature, pH stability, temperature stability, thermal inactivation, substrate specificity, effect of enzyme concentration, effect of substrate concentration, activation energy, and effect of inhibitor and activator. The molecular mass of acid phosphatase was estimated to be 58 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The optimum pH was 5.7 and the optimum temperature was 50 degrees C. The enzyme was stable at pH 4.0-10.0 and 40-60 degrees C. Activation energy was between 10 and 20 kcal, and as Michaelis Menten coefficients, Vm values were 100 and 20 mM/s and Km values were 21.27 and 8.33 mM for paranitrophenylphosphate and paranitrophenyl, respectively. Studies of the effect of metal ions on enzyme activity showed both an activating and a deactivating effect. While Cu, Mo, and Mn showed strong inhibitory effects, Na, Ca, and K were the significant activators of acid phosphatase.


Asunto(s)
Fosfatasa Ácida/metabolismo , Ajo/enzimología , Fosfatasa Ácida/aislamiento & purificación , Cromatografía DEAE-Celulosa/métodos , Estabilidad de Enzimas , Concentración de Iones de Hidrógeno , Cinética , Metales/farmacología , Especificidad por Sustrato , Termodinámica
17.
Biosci Biotechnol Biochem ; 67(1): 68-76, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12619675

RESUMEN

The fruit extracts of ripening cv. Japanese Persimmon, "Saijyo", contained a number of glycosidases and glycanases. Among them, beta-galactosidase appeared to be the most significant, and the activity increased in parallel with tissue ripening. Persimmon beta-galactosidase was presented in at least three isoforms, beta-galactosidase-I (pI = 4.88), beta-galactosidase-II (pI = 6.76), and beta-galactosidase-III (pI = 7.05). beta-Galactosidase-III had exo-type galactanase activity, while the others did not. The activity of endo-type glycanases was a maximum in immature green or yellow fruits. The firmness of the pulp tissue decreased dramatically, and the amount of water-soluble polysaccharide (WSS) increased. The enzyme activities of exo-type glycosidases, especially beta-galactosidase, appeared maximal in mature red fruits. The amount of extractable pectin remained unchanged, although the galactose content of the high-molecular-weight fraction in WSS decreased dramatically. These results suggest that the ripening of persimmon was caused by the solubilization of pectic polysaccharide by endo-type glycanases and digestion by exo-type glycosidases. beta-Galactosidase, in particular, seemed to play a major role in ripening the fruit.


Asunto(s)
Diospyros/enzimología , Diospyros/crecimiento & desarrollo , beta-Galactosidasa/fisiología , Carbohidratos/química , Cromatografía DEAE-Celulosa , Cromatografía en Gel , Cromatografía Líquida de Alta Presión , Electroforesis en Gel de Poliacrilamida , Glicósido Hidrolasas/química , Glicósido Hidrolasas/aislamiento & purificación , Concentración de Iones de Hidrógeno , Indicadores y Reactivos , Peso Molecular , Extractos Vegetales/química , Proteínas de Plantas/química , Polisacáridos/química , Polisacáridos/aislamiento & purificación , beta-Galactosidasa/química , beta-Galactosidasa/aislamiento & purificación
18.
Biosci Biotechnol Biochem ; 66(10): 2068-76, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12450116

RESUMEN

A major species of glutathione S-transferase (GST), Pugf, was highly purified from pumpkin flowers. Two-dimensional electrophoresis of the purified enzyme gave two adjacent protein spots. The specific activity of the purified enzyme was 2.4 micromol min(-1) mg(-1) protein for 1-chloro-2,4-dinitrobenzene. This value is one to two orders of magnitude lower than that of pumpkin tau-type GSTs. The expression pattern of Pugf in healthy pumpkin plants and responses to various stresses were examined by western blotting. Pugf was found in high concentrations in petioles, stems, and roots as well as flowers, and was more abundant in expanding young organs than in fully expanded mature organs. Dehydration caused a slight increase in its concentration, but high and low temperatures, salty stress, and 2,4-dichlorophenoxyacetic acid seemed to have no effects. A cDNA encoding Pugf was cloned and sequenced. Sequence comparison with other plant GSTs suggested that it should be classified as a phi-type GST.


Asunto(s)
Cucurbita/enzimología , ADN Complementario/biosíntesis , Flores/enzimología , Glutatión Transferasa/aislamiento & purificación , Ácido 2,4-Diclorofenoxiacético/toxicidad , Formación de Anticuerpos , Especificidad de Anticuerpos , Western Blotting , Cromatografía DEAE-Celulosa , Clonación Molecular , Reacciones Cruzadas , ADN Complementario/química , ADN Complementario/aislamiento & purificación , Electroforesis en Gel de Poliacrilamida , Glutatión Transferasa/genética , Herbicidas/toxicidad , Proteínas de Plantas/aislamiento & purificación
19.
Carbohydr Res ; 337(18): 1687-96, 2002 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-12423972

RESUMEN

Pectins from sugar beet, lime and apple were degraded by a rhamnogalacturonan hydrolase associated or not with pectin methylesterases and side chain degrading enzymes (galactanase and arabinanase). The composition of the enzymatic mixture was optimised by following the reaction by viscosimetric means. The reaction products were fractionated by ion exchange chromatography. Treatment with all the enzymes released four fractions: (1). 227-247 mg/g of initial pectins and corresponded to neutral sugars from the side chains; (2,3). represented together 184-220 mg/g of pectins and corresponded to rhamnogalacturonan; (4). 533-588 mg/g of pectins and corresponded to homogalacturonan. Lime pectins have the shortest rhamnogalacturonan regions. The molar masses of homogalacturonans were in the range of 16000-43400 g/mol according to the origin of pectins, corresponding to degrees of polymerisation of 85-250. The mode of action of the enzymes used is also discussed.


Asunto(s)
Hidrolasas de Éster Carboxílico/química , Glicósido Hidrolasas/química , Pectinas/química , Beta vulgaris/química , Hidrolasas de Éster Carboxílico/metabolismo , Cromatografía DEAE-Celulosa/métodos , Cromatografía en Gel , Citrus/química , Glicósido Hidrolasas/metabolismo , Malus/química , Peso Molecular , Pectinas/metabolismo , Viscosidad
20.
Nahrung ; 45(5): 324-31, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11715343

RESUMEN

The influence of structural features of the cell wall polysaccharides pectin and cellulose on the enzymatic degradation of red beet was evaluated. Alcohol-insoluble substances and acetone-insoluble residues were prepared from red beets and characterized with respect to the content of dietary fibre, pectin fractions, neutral saccharide composition and water absorption. The high-methylated and high-acetylated pectin component was partly soluble in water and in EDTA. Pectin was hardly extractable from alcohol-insoluble substances as well as from red beets. Isolated pectin could not be completely degraded by pectolytic enzymes. After de-acetylation, the pectic acid from red beets was degradable in a similar rate like citrus pectic acid. From alcohol-insoluble substances, several cellulose and lignin fractions were prepared and analysed. A cellulose preparation from red beets was intensely degraded by cellulases with high activities as shown by the release of reducing end-groups, viscosity and scanning electron microscopy. Cell wall preparations from red beets were able to bind high amounts of water. A decrease in water absorption during enzymatic action or changes in viscosity and flow behaviour are sensitive markers for decomposition or depolymerization processes. Furthermore, an inhibitor of microbial enzymes was isolated from red beets and acetone-insoluble residues. The main reason for the poor enzymatic liquefaction or maceration of red beets by pectolytic and cellulolytic enzymes is the high degree of acetylation of the pectin component.


Asunto(s)
Beta vulgaris/enzimología , Celulasa/metabolismo , Celulosa/metabolismo , Pectinas/metabolismo , Beta vulgaris/química , Beta vulgaris/metabolismo , Pared Celular/ultraestructura , Cromatografía DEAE-Celulosa , Cromatografía por Intercambio Iónico , Microscopía Electrónica de Rastreo , Solubilidad , Viscosidad
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