Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q86TM3 (cage)
 29,987 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The nuclear magnetic spin-lattice relaxation rates of water protons are reported for solutions of manganese(II), copper(II), and chromium(III) cage complexes of the sarcophagine type. As simple aqueous solutions, the complexes are only modest magnetic relaxation agents, presumably because they lack protons on atoms in the first-coordination-sphere protons that are sufficiently labile to mix the large relaxation rate at the metal complex with that of the bulk solvent. The relaxation is approximately modeled using spectral density functions derived for translational diffusion of the interacting dipole moments with the modification that the electron spin relaxation rate is directly included as a contribution to the correlation time. In all cases studied, the electron spin relaxation rate is sufficiently large that it contributes directly to the water-proton spin relaxation process. The poor relaxation efficiency of the cage compound may, however, be improved dramatically by binding the complex to a protein. The efficiency is improved even further if the rotational motion of the protein is reduced drastically by an intermolecular cross-linking reaction. The relaxation efficiency of the cross-linked protein-cage complexes rivals that of the best first-coordination-sphere relaxation agents like [Gd(DTPA)(H2O)]2- and [Gd(DOTA)(H2O)]-.
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PMID:Nuclear magnetic spin-lattice relaxation of water protons caused by metal cage compounds. 131 46

Capillary endothelial cells have a large population of small (65-80 nm diameter in transmission electron microscopy) vesicles of which a large fraction is associated with the plasmalemma of the luminal and abluminal side. We studied the fine structure and distribution of these plasmalemmal vesicles by high resolution scanning electron microscopy in cultured endothelial cells obtained from bovine adrenal cortical capillaries. Cell monolayers were covered with polylysine-coated silicon chips, split in high potassium buffer, fixed in aldehyde mixtures, and then treated with OsO4 and thiocarbohydrazide. After critical point drying, the specimens were coated with a thin (less than 2 nm) continuous film of chromium. On the cytoplasmic aspect of the dorsal plasmalemmal fragments seen in such specimens, plasmalemmal vesicles appear as uniform vesicular protrusions approximately 70-90 nm in diameter, preferentially concentrated in distinct large fields in which they occur primarily as single units. Individual plasmalemmal vesicles exhibit a striped surface fine structure which consists of ridges approximately 10 nm in diameter, separated by furrows and oriented as meridians, often ending at two poles on opposite sides of the vesicles in a plane parallel to the plasmalemma. This striped surface structure is clearly distinct from the cage structure of coated pits found, at low surface density, on the same specimens. The cytoplasmic aspect of the plasmalemma proper is covered by a fibrillar infrastructure which does not extend over plasmalemmal vesicles but on which the latter appear to be anchored by fine filaments.
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PMID:Endothelial plasmalemmal vesicles have a characteristic striped bipolar surface structure. 406 56

An increased risk of cancer associated with nickel refining and with chromate production has been known for some decades. The occupational exposure pattern of both nickel and chromium is very complex. Even though nickel carbonyl is an experimental carcinogen, there are no data supporting its carcinogenicity in humans. Nickel subsulfide may be the most potent carcinogen among the different nickel compounds. A correlation between lung cancer and exposure to chromates has been shown in several studies. As yet, there are no epidemiologic data indicating carcinogenicity of chromium(III) salts. Hexavalent chromium, however, has been suggested as the causative carcinogen among platers and ferrochromium workers. There is an urgent need for careful dose registration before a quantitative cancer risk analysis can be performed for the nickel and chromium industry.
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PMID:Cancer hazards caused by nickel and chromium exposure. 746 13

The reagent Li[7-NHBu(t)()-nido-7-CB(10)H(12)] reacts with [Mo(CO)(6)] in NCMe at reflux temperatures, followed by addition of [N(PPh(3))(2)]Cl, to give [N(PPh(3))(2)][1,2-mu-NHBu(t)-2,2,2-(CO)(3)-closo-2,1-MoCB(10)H(10)] (1). The tungsten (2) and chromium (3) analogues were similarly obtained, but the latter is unstable and was isolated in low yield. An X-ray diffraction study of 2 confirmed that the exo-polyhedral NHBu(t) group forms a bridge between the cage-carbon atom and the tungsten. For 1, this intramolecular donor bond is lifted on protonation in the presence of donor molecules L (CO, PPh(3), PMe(3), PEt(3), PMe(2)Ph) when zwitterionic complexes [1-NH(2)Bu(t)()-2,2,2-(CO)(3)-2-L-closo-2,1-MoCB(10)H(10)] (4) are formed. In contrast, protonation with HCl gives a salt [N(PPh(3))(2)][1-NH(2)Bu(t)()-2,2,2-(CO)(3)-2-Cl-closo-2,1-MoCB(10)H(10)] (5). Complex 1 in CH(2)Cl(2) with CNBu(t) is oxidized by iodine, affording [1,2-mu-NHBu(t)()-2,2,2-(CNBu(t)())(3)-2-I-closo-2,1-MoCB(10)H(10)] (6a). Treatment of 1 with [CuCl(PPh(3))](4) in the presence of Tl[PF(6)] yields the bimetallic compound [exo-[Cu(PPh(3))]-1,2-mu-NHBu(t)-2,2,2-(CO)(3)-closo-2,1-MoCB(10)H(10)] (8), whereas reaction with [AuCl(PPh(3))] and Tl[PF(6)] affords a mixture of [1,2-mu-NHBu(t)-2-[Au(PPh(3))]-2,2,2-(CO)(3)-closo-2,1-MoCB(10)H(10)] (9) and [Au(PPh(3))(2)][2,2'-mu-Au-[1,2-mu-NHBu(t)-2,2,2-(CO)(3)-closo-2,1-MoCB(1)(0)H(10)](2)] (10a). In solution, 9 disproportionates, giving 10a. The [N(PPh(3))(2)](+) salt (10b) is readily prepared by treating 1 with [AuCl(THT)] (THT = tetrahydrothiophene) and Tl[PF(6)], and its structure was determined by X-ray diffraction.
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PMID:Synthesis and reactivity of the monocarbon molybdenacarborane anion [1,2-mu-NHBu(t)-2,2,2-(CO)(3)-closo-2,1-MoCB(10)H(10)](-). 1173 64

The ionic multicomponent complex complex: ([Cr(I)(PhH)(2)].+))(2)[Co(II)TPP(C(60)(CN)(2))]-[C(60)(CN)(2)](.-).3(o-C(6)H(4)Cl(2)) (Co(II)TPP: cobalt (II) tetraphenylporphyrin; Cr(PhH)(2): bis(benzene)chromium; o-C(6)H(4)Cl(2): o-dichlorobenzene) containing CoTPP(C(60)(CN)(2)- anion and C(60)(CN)(2).- radical anion was obtained. The complex has the cage structure with channels, which accommodate Cr(I)(PhH)(2)(.+) and o-C(6)H(4)Cl(2) molecules. For the first time the sigma-bonding of Co(II)TPP to the fullerene radical anion with the essentially shortened Co.C(C(60)(CN)(2)) contact of 2.282 A is observed. The sigma-bonding results in the diamagnetism of Co(II)TPP(C(60)(CN)(2))(-) anion. The nonbonded C(60)(CN)(2)(.-) radical anion retains both the C(2)(v)symmetry and the shape of the molecule. The length of the C(triple bond)N bonds is 1.141 and 1.152 A.
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PMID:Synthesis and crystal structure of ionic multicomponent complex: ([Cr(I)(PhH)(2)].+))(2)[Co(II)TPP(C(60)(CN)(2))]-[C(60)(CN)(2)](.-).3(o-C(6)H(4)Cl(2)) containing C(60)(CN)(2).- radical anion and sigma-bonded diamagnetic Co(II)TPP(C(60)(CN)(2)) -anion. 1208 5

The photoelectron spectra of chromium-doped silicon cluster anions, CrSi-(n), were measured over the size range, n=8-12. Their vertical detachment energies were measured to be 2.71, 2.88, 2.87, 2.95, and 3.18 eV, respectively. Our results support theoretical calculations by Khanna, Rao, and Jena [Phys. Rev. Lett. 89, 016803 (2002)] which found CrSi12 to be an enhanced stability (magic) cluster with its chromium atom encapsulated inside a silicon cage and with its magnetic moment completely quenched by the effects of the surrounding cage.
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PMID:Photoelectron spectroscopy of chromium-doped silicon cluster anions. 1574 12

This study evaluated regression of total P output against dietary P intake to simultaneously estimate endogenous P loss and true P utilization in broiler chicks. Soybean meal (SBM) served as the model ingredient, and a comparison was made between conventional and low-phytate SBM varieties. These feedstuffs were chosen to minimize nutritive differences to dietary phytate content. Low-phytate SBM contained 57% less phytate than conventional SBM. Four isocaloric diets were formulated to contain graded levels of each soybean meal (8 diets total); therefore, the diets also contained graded levels of dietary P. Chromium sesquioxide was included in diets as an indigestible marker, and free access to experimental diets was provided to 288 male broiler chicks from 15 to 22 d posthatch. The experiment was arranged as a randomized complete block design with 6 blocks of 8 cages (6 birds per cage) and similar initial BW across dietary treatments. As P intake ranged from 0.9 to 3.9 g/ kg of DM, apparent prececal P digestibilities increased (linear and quadratic, P < 0.01) for conventional SBM and low-phytate SBM. Increasing linear relationships (P < 0.01) were observed for total P output (mg/kg of DM intake) with graded P intake, regardless of SBM variety. True P retention was greater (P < 0.01) for low-phytate SBM (76.9%) than for conventional SBM (59.8%). Endogenous P estimates were not different between soybean meals (P > 0.10), and an overall estimate of 235 mg of P/ kg of DM intake was observed. This study concluded 1) the regression approach may be applicable in the estimation of endogenous P loss in broiler chicks and 2) the difference in P utilization between conventional and low-phytate soybean meals is influenced by dietary phytate content when broiler chicks are fed P-deficient diets.
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PMID:Estimation of true phosphorus digestibility and endogenous phosphorus loss in growing chicks fed conventional and low-phytate soybean meals. 1661 50

Recent analyses have revealed that 38% of municipal sources of drinking water in California have detectable levels of hexavalent chromium. This observation provided new impetus to characterize the carcinogenic risk associated with oral exposure to hexavalent chromium in drinking water. Notwithstanding the well-characterized increases in cancer associated with inhalation exposure to this chemical, the marked reduction of hexavalent chromium to trivalent chromium in the stomach suggests that exposure to hexavalent chromium in drinking water may not pose a carcinogenic risk. A reevaluation of studies that investigated the toxicokinetics, the genotoxicity, and the mechanism of carcinogenicity of hexavalent chromium, as well as the available human and animal cancer studies, was undertaken to determine if there is evidence that exposure to this chemical in drinking water may pose a carcinogenic risk. Mechanistic studies suggest the potential for a carcinogenic response if hexavalent chromium enters cells. Both toxicokinetic and genotoxicity studies indicate that a portion of an orally administered dose of hexavalent chromium is absorbed and gets into cells of several tissues, causing DNA damage. The only lifetime oral study of hexavalent chromium in animals conducted thus far yielded a statistically significant increase in stomach tumors compared to controls. Also, in a limited-term cancer study, co-exposure to hexavalent chromium in drinking water and ultraviolet light produced skin tumors in mice. The only available cancer study of humans exposed to hexavalent chromium in drinking water revealed a statistically significant increase in stomach tumors. Moreover, a meta-analysis of occupational studies also revealed a statistically significant increase in stomach cancers. The increases in stomach tumors in both human and animal studies, along with the toxicokinetic, genotoxic, and mechanistic data, suggest that oral exposure to this agent appears to pose a carcinogenic risk.
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PMID:Review of the evidence regarding the carcinogenicity of hexavalent chromium in drinking water. 1669 May 39

The manuscript describes removal of chromium from aqueous solution by biomass of different moulds and yeasts. The biomass of Termitomyces clypeatus (TCB) is found to be the most effective of all the fungal species tested. The sorption of hexavalent chromium by live TCB depends on the pH of the solution, the optimum pH value being 3.0. The process follows Langmuir isotherm (regression coefficient 0.998, chi(2)-square 5.03) model with uniform distribution over the surface which gets strong support from the X-ray elemental mapping of chromium adsorbed biomass. The amino, carboxyl, hydroxyl, and phosphate groups of the biomass are involved in chemical interaction with the chromate ion forming a cage like structure depicted by scanning electron microscopic (SEM) and Fourier transform infrared spectroscopic (FTIR) results. Desorption and FTIR studies also exhibited that Cr(6+) is reduced to trivalent chromium on binding to the cell surface. The level of chromium concentration present in the effluent of tannery industries' is reduced to a permissible limit using TCB as adsorbent.
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PMID:Biosorption of chromium by Termitomyces clypeatus. 1761 91

Recent research has indicated that MUC4 plays an important role in the development of many tumors and may prove useful as a novel cancer immunotherapy target. We aimed to identify HLA-A*0201-restrictive cytotoxic T lymphocyte (CTL) epitopes of the cancer-associated antigen MUC4. The MUC4 sequence was scanned for immunogenic peptides using HLA-binding prediction software. Dendritic cells (DCs) from peripheral blood mononuclear cells (PBMCs) were induced by cytokines. Five possible CTL epitopes were selected by software analysis, synthesized, and used to pulse mature DCs. The CD8(+) T cells from PBMCs from an HLA-A*0201 healthy donor were stimulated with autologous MUC4-peptide-loaded DCs and expanded in vitro. T cell activation was assessed by ELISPOT, and cytotoxicity was determined by (51)chromium ((51)Cr)-release assays. Our results show that CTLs induced by peptide P01204 could lyse T2 cells pulsed with peptide P01204 and HCT-116 cells (MUC4(+), HLA-A2(+)). Compared with a control peptide, P01204 increased the number of IFN-gamma producing T cells. Overall, these results suggest that P01204 is a novel HLA-A*0201-restrictive CTL epitope of the cancer-associated antigen MUC4. This will provide a foundation for the development of tumor-specific peptide vaccines.
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PMID:Identification of an HLA-A*0201-restrictive CTL epitope from MUC4 for applicable vaccine therapy. 2295 48


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