			Home About us Contact

Insoluble Material (insoluble + material)

Distribution by Scientific Domains

Chemistry	50%
Life Sciences	33%

Selected Abstracts

Nitric oxide-dependent protein synthesis in parotid and submandibular glands of anaesthetized rats upon sympathetic stimulation or isoprenaline administration

EXPERIMENTAL PHYSIOLOGY, Issue 2 2004
Shariel Sayardoust
In anaesthetized female rats, the ,-adrenoceptor agonist isoprenaline was intravenously infused (20 ,g kg,1 min,1) for 30 min or the ascending cervical sympathetic nerve trunk was intermittently stimulated (50 Hz, 1 s every tenth second) on one side for 30 min. The incorporation of [3H]leucine into trichloroacetic acid (TCA)-insoluble material was used as an index of protein synthesis. In response to isoprenaline, the [3H]leucine incorporation increased by 79% in the parotid glands and by 82% in the submandibular glands. The neuronal type NO-synthase inhibitor N-PLA, reduced (P < 0.001) this response to 26% and 20%, respectively. Sympathetic stimulation under ,-adrenoceptor blockade increased the [3H]leucine incorporation by 192% in the parotid glands and by 35% in the submandibular glands. N-PLA reduced the corresponding percentage figures to 86% (P < 0.01) and 8% (P < 0.05). When tested in the parotid glands, the non-selective NO-synthase inhibitor L -NAME reduced (P < 0.01) the nerve-evoked response to 91%. The increase in [3H]leucine incorporation in response to sympathetic stimulation under ,-adrenoceptor blockade was not affected by N-PLA in the parotid (139%versus 144%) and submandibular glands (39%versus 34%). In non-stimulated glands, the [3H]leucine incorporation was not influenced by the NO-synthase inhibitors. In conclusion, ,-adrenoceptor mediated salivary gland protein synthesis is largely dependent on NO generation by neuronal type NO-synthase, most likely of parenchymal origin. [source]

Radiotracer-based method for determining water solubility of highly insoluble compounds

JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 9 2006
Ketai Wang
Abstract Ascertaining the aqueous solubility of compounds is important in the selection of drug candidates. We describe a radiotracer method for estimating water solubility of compounds that are soluble in dimethyl sulfoxide (DMSO). Various volumes of DMSO, saturated with 127I-labeled compound and spiked with the corresponding 125I-labeled derivative, are mixed in de-ionized water and the tubes centrifuged to remove insoluble material. Since (i) the iodine-127 and iodine-125 compounds have the same solubilities and are equally distributed in the DMSO,water solution, and (ii) the nonradioactive compound is accurately weighed, dissolved in a known volume of DMSO, and then further diluted as required, the concentration of compound in solution can be calculated and plotted as a function of the DMSO-to-water ratio. Water solubility of the compound is then determined by extrapolation of the linear fit of data points to zero DMSO. As proof of the methodology, 5-iodo-2,-deoxyuridine (IUdR) and 2-iodo-8-methyl-8H -quino[4,3,2- kl]acridine (IMAc), water-soluble compounds, were assessed using 125IUdR and 125IMAc, respectively. The solubility values obtained by the radiotracer method were similar to those acquired by spectrophotometry. Values calculated for several water-insoluble compounds indicate that the radiotracer method can accurately quantify the solubility of low-molecular-weight compounds (1000,2000 Da) in the pg,ng/ml range. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Identification of Cytokeratins in Bovine Sperm Outer Dense Fibre Fractions

REPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2003
E Hinsch
Contents Outer dense fibres (ODF) are important substructures of mammalian sperm tails that are involved in the regulation of sperm motility. In this study, we investigated the identity of several sodium dodecyl sulphate (SDS)-insoluble ODF proteins. Bovine ODF were purified by separating sperm heads and tails using ultrasound and Percoll® density gradient centrifugation. Sperm flagella were treated with the detergent cetyltrimethylammonium bromide (CTAB). CTAB-insoluble material, which reportedly represents the ODF fraction, was collected, and electron microscopy confirmed a highly purified ODF fraction. We found after solubilization of this fraction with SDS that high amounts of insoluble material were retained after centrifugation. SDS-insoluble material was collected and quantitatively dissolved in 8 M urea. SDS-gel electrophoresis in the presence of urea revealed polypeptides with apparent molecular masses of approximately 25, 43, and 50 kDa. Subsequent immunoblotting with anti-cytokeratin antibodies detected two urea-soluble, SDS-insoluble proteins with apparent molecular masses of 45 and 66 kDa. The 45-kDa protein was identified as cytokeratin 19. An antibody reacting with a palette of cytokeratins (CK 1,18 and CK 20), KL1, was the only antibody that reacted with the 66-kDa polypeptide. We conclude that sperm ODF fractions contain at least one each of type I and type II intermediate filaments. As keratins and intermediate filaments are described as rope-like structures, we suggest that these intermediate filaments play an important structural or tension-bearing role in sperm flagella. [source]

Proteome analysis of human nuclear insoluble fractions

GENES TO CELLS, Issue 8 2009
Hideaki Takata
The interphase nucleus is a highly ordered and compartmentalized organelle. Little is known regarding what elaborate mechanisms might exist to explain these properties of the nucleus. Also unresolved is whether some architectural components might facilitate the formation of functional intranuclear compartments or higher order chromatin structure. As the first step to address these questions, we performed an in-depth proteome analysis of nuclear insoluble fractions of human HeLa-S3 cells prepared by two different approaches: a high-salt/detergent/nuclease-resistant fraction and a lithium 3,5-diiodosalicylate/nuclease-resistant fraction. Proteins of the fractions were analyzed by liquid chromatography electrospray ionization tandem mass spectrometry, identifying 333 and 330 proteins from each fraction respectively. Among the insoluble nuclear proteins, we identified 37 hitherto unknown or functionally uncharacterized proteins. The RNA recognition motif, WD40 repeats, HEAT repeats and the SAP domain were often found in these identified proteins. The subcellular distribution of selected proteins, including DEK protein and SON protein, demonstrated their novel associations with nuclear insoluble materials, corroborating our MS-based analysis. This study establishes a comprehensive catalog of the nuclear insoluble proteins in human cells. Further functional analysis of the proteins identified in our study will significantly improve our understanding of the dynamic organization of the interphase nucleus. [source]

Insoluble Perfluoroalkylated Polymers: New Solid Supports for Supported Fluorous Phase Catalysis

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2010
Nicolas Audic
Abstract New perfluoroalkylated polystyrene resins have been prepared by the suspension polymerisation of 4-(perfluoro- n -octyl)styrene. The evaluation of these highly fluorinated insoluble materials as catalyst supports for rhodium-catalysed hydrogenation of styrene and palladium-mediated Suzuki,Miyaura carbon-carbon bond forming reactions with 4-bromoacetophenone and 4-bromoanisole revealed improvements in the recycling of the perfluoroalkylated catalysts as compared to that achieved using fluorous reverse-phase silica gel. [source]

Dithiolate-Bridged Fe-Ni-Fe Trinuclear Complexes Consisting of Fe(CO)3,n(CN)n (n=0, 1) Components Relevant to the Active Site of [NiFe] Hydrogenase

CHEMISTRY - AN ASIAN JOURNAL, Issue 6 2009
Satyanarayan Pal Dr.
Abstract Step-by-step: A trinuclear Fe-Ni-Fe complex 1 was synthesized from the reaction of [Fe(CO)4I2] with Li2[Ni(norbornane- exo -2,3-dithiolate)2]. The CO ligands in 1 were transformed into CN, upon treatment with ,N(SiMe3)2, and the monocyanide complex 3 and the dicyanide complex 4 were obtained. Complexes 3 and 4 were found to react with protonic acids, whereas 1 is robust. A dithiolate-bridged Fe-Ni-Fe trinuclear carbonyl complex [(CO)3Fe(,-ndt)Ni(,-ndt)Fe(CO)3] (1, ndt=norbornane- exo -2,3-dithiolate) has been synthesized from the reaction of [Fe(CO)4I2] and Li2[Ni(ndt)2]. This reaction was found to occur with concomitant formation of a tetranuclear cluster [Ni3(,-ndt)4FeI] (2). Treatment of 1 with Na[N(SiMe3)2] transforms some of the CO ligands into CN,, and the monocyanide complex (PPh4)[(CO)2(CN)Fe(,-ndt)Ni(,-ndt)Fe(CO)3] (3) and the dicyanide complex (PPh4)2[(CO)2(CN)Fe(,-ndt)Ni(,-ndt)Fe(CO)2(CN)] (4) were isolated. X-ray structural analyses of the trinuclear complexes revealed a Fe-Ni-Fe array in which the metal centers are connected by the ndt sulfur bridges and direct FeNi bonds. Hydrogen bonding between the CN ligand in 3 and cocrystallized ethanol was found in the solid-state structure. The monocyanide complex 3 and dicyanide complex 4 reacted with acids such as HOTf or HCl generating insoluble materials, whereas complex 1 did not react. [source]