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Query: UNIPROT:P06889 (
Mol
)
630,302
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Fe(III), Cu(II), Co(III), and Mn(III) complexes of ovo- and human serum transferrins show resonance enhanced Raman bands near 1600, 1500, 1270, and 1170 cm-1 upon excitation with laser frequencies which fall within the visible absorption bands of those metalloproteins. Comparison of the visible absorption and resonance Raman spectra of the Cu(II)-transferrin complexes with those for the Cu(II) model compound, bis(2,4,6-trichlorophenolato)diimidazolecopper(II) monohydrate, indicates that the resonance Raman bands are due to enhancement of phenolic vibrational modes. For the model (Cu(II) compound, a normal coordinate analysis was used to aid our assignment of the observed resonance bands at 1562, 1463, 1311, and 1122 cm-1 to A1 vibrational modes of the 2,4,6-trichlorophenolato moiety. These assignments are consistent with those made for Cu(II)-transferrins. The latter assignments were based upon calculated A1 frequencies for p-methylphenol (Cummings, D.L., and Wood, J.L. (1974), J.
Mol
. Struct. 20, 1). The wavelength shifts in the resonance bands for the model compound from those for Cu(II)-transferrins are due to the influence of the chloro substituents on the planar vibrations of
phenol
. These results clearly identify tyrosine as a ligand in copper binding to transferrins.
...
PMID:Resonance Raman spectra of iron(III)-, copper(II)-, cobalt(III)-, and manganese(III)-transferrins and of bis(2,4,6-trichlorophenolato)diimidazolecopper(II) monohydrate, a possible model for copper(II) binding to transferrins. 99 Feb 53
The secondary structure of pre-mRNA species from mouse Ehrlich ascites carcinoma cells extracted with
phenol
at the temperatures either 55-65 degrees C or 65-85 degrees C was investigated. A fraction of the double helical regions of pre-mRNA was estimated by two methods: a) by recording of melting curves; b) by measuring fluorescence lifetimes of acridine orange dye adsorbed on the nucleic acid. This fraction was about 64-68%. Further lowering of ionic strength down to 0.024 results in 10-15% decrease in the fraction of double regions. Both lowering of ionic strength and increase of the temperature up to 50-55 degrees C results in despiralisation of pre-mRNA regions which contain more than 70% of AU-nucleotide pairs. Only regions containing mainly GC-nucleotide pairs remain double-stranded under heating to temperatures above 50 degrees C. These facts were established on the basis of studies of acriflavin dye complexes with pre-mRNA.
Mol
Biol (Mosk)
PMID:[Secondary structure of nuclear precursors of the informational RNA (pre-mRNA)]. 105 71
A relatively simple and inexpensive method has been developed for the preparation of highly purified rabbit reticulocyte globin mRNA. After
phenol
extraction, polysomal RNA was chromatographed on Sigmacell type 38 cellulose and Sepharose 4B. The resulting mRNA preparation has a purity in excess of 90%. No selective loss of either alpha or beta globin mRNA is observed.
Mol
Biol Rep 1975 Dec
PMID:A simple method for the purification of reticulocyte globin messenger ribonucleic acid. 121 85
Lipopolysaccharide (LPS) extraction from smooth-type Salmonella enterica sv. Typhimurium was carried out with the modified
phenol
/chloroform/petroleum ether method (volume ratio 5:5:8). In this procedure, LPS was precipitated from 90%
phenol
sequentially with water and acetone to yield LPS-H2O (minute amounts) and LPS-Ac (major amounts), respectively. Chemical analyses of the LPS fractions revealed that in the O antigen of LPS-H2O position C4 of the D-galactose was extensively glucosylated, corresponding corresponding to the O-antigen factor 122. In LPS-Ac, this glucosylation was negligible. Inspection of the LPS fractions by sodium dodecyl sulphate/polyacrylamide gel electrophoresis and silver staining suggested that the glucosylation in LPS-H2O was present only in LPS species with a chain length higher than six repeating units.
Mol
Microbiol 1992 Oct
PMID:Separation of two lipopolysaccharide populations with different contents of O-antigen factor 122 in Salmonella enterica serovar typhimurium. 127 61
Two of the major cell types in bone marrow stroma, macrophages and fibroblasts, have been shown to be important regulators of both myelopoiesis and lymphopoiesis. The enzymology relating to cell-specific metabolism of phenolic metabolites of benzene in isolated mouse bone marrow stromal cells was examined. Fibroblastoid stromal cells had elevated glutathione-S-transferase (4.5-fold) and DT-diaphorase (4-fold) activity relative to macrophages, whereas macrophages demonstrated increased UDP-glucuronosyltransferase (UDP-GT, 7.5-fold) and peroxidase activity relative to stromal fibroblasts. UDP-GT and glutathione-S-transferase activities in macrophages and fibroblasts, respectively, were significantly greater than those in unpurified white marrow. Aryl sulfotransferase activity could not be detected in either bone marrow-derived macrophages or fibroblasts, and there were no significant differences in GSH content between the two cell types. Because UDP-GT activity is high in macrophages, these data suggest that DT-diaphorase levels would be rate limiting in the detoxification of benzene-derived quinones in bone marrow macrophages. The peroxidase responsible for bioactivation of benzene-derived phenolic metabolites in bone marrow macrophages is unknown but has been suggested to be prostaglandin H synthase (PGS). Hydrogen peroxide, but not arachidonic acid, supported metabolism of hydroquinone to reactive species in bone marrow-derived macrophage lysates. These data do not support a major role for PGS in peroxidase-mediated bioactivation of hydroquinone in bone marrow-derived macrophages, although PGS mRNA could be detected in these cells. Similarly, hydrogen peroxide, but not arachidonic acid, supported metabolism of hydroquinone in a human bone marrow homogenate. Peroxidase-mediated interactions between phenolic metabolites of benzene occurred in bone marrow-derived macrophages. Bioactivation of hydroquinone to species that would bind to acid-insoluble cellular macromolecules was increased by
phenol
and was markedly stimulated by catechol. Bioactivation of catechol was also stimulated by
phenol
but was inhibited by hydroquinone. These data define the enzymology and the cell-specific metabolism of benzene metabolites in bone marrow stroma and demonstrate that interactions between phenolic metabolites may contribute to the toxicity of benzene in this critical bone marrow compartment.
Mol
Pharmacol 1992 Dec
PMID:Cell-specific metabolism in mouse bone marrow stroma: studies of activation and detoxification of benzene metabolites. 148 Jan 34
A cDNA encoding minoxidil sulfotransferase (Mx-ST), a rat liver cytosolic sulfotransferase that catalyzes the 3'-phosphoadenosine 5'-phosphosulfate-dependent sulfate conjugation of minoxidil and p-nitrophenol, has been isolated from a lambda gt11 cDNA library constructed from poly(A)+ RNA isolated from female Sprague-Dawley rat liver. The largest cDNA, designated Mx-STb, consists of 1245 base pairs and contains an open reading frame of 291 amino acids. The predicted size of the protein translated by Mx-STb is 33,909 Da; however, the molecular mass of the pure protein [Biochem. J. 270:721-728 (1990)] is estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 35,000 Da. The size of the protein obtained by in vitro translation of Mx-STb is identical to that of the pure protein. Results of initial studies of the expression of Mx-STb in COS-1 cells indicate that the expressed protein displays characteristic Mx-ST and p-nitrophenol sulfotransferase activity, is recognized by rabbit polyclonal antibodies raised against pure rat liver Mx-ST, and migrates at approximately 35,000 Da during sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This paper presents the cloning and expression of a rat phenol sulfotransferase for which the physical, immunological, and kinetic properties are known. Isolation of the cDNA for Mx-ST will aid in the investigation of the heterogeneity, the tissue localization, and the characterization of the kinetic properties of this important drug-metabolizing enzyme, with respect to other similar
phenol
sulfotransferases present in rat liver cytosol.
Mol
Pharmacol 1992 Aug
PMID:Sequence analysis, in vitro translation, and expression of the cDNA for rat liver minoxidil sulfotransferase. 151 23
MCF-7 cells were grown in serum free medium (Dulbecco MEM without
phenol
red, supplemented with Costar SF-1 without insulin). Insulin was added as required and gave dose dependent growth stimulation at concentrations between 5 and 10,000 nM. Identical growth response curves were obtained for thymidine uptake and cell number. Oestradiol and insulin-like growth factor I (IGF-I) added individually both gave a dose dependent stimulation of cell growth in serum free medium containing 50 nM insulin. The growth stimulatory effect of oestradiol was to a large extent inhibited with suramine, a general inhibitor of growth factors, indicating that the effect of oestradiol was mediated through stimulating autocrine secretion of a growth factor. To investigate a possible link between the effects of oestradiol and IGF-I, a specific IGF-I receptor antibody (alpha IR-3), 10 micrograms/ml was used. These experiments were carried out with 2.5 nM insulin in the medium, a concentration at which insulin had no growth stimulatory effect. Stimulation was carried out for 18 h before assay of thymidine uptake. The effect of oestradiol was not significantly reduced by alpha IR-3, indicating that IGF-I was not an autocrine mediator of oestradiol stimulation of cell growth under these conditions, whereas alpha IR-3 extensively reduced growth stimulation by IGF-I. On long term stimulation (5 days) oestradiol had a marked stimulatory effect on cell number and alpha IR-3 almost totally abrogated this effect. When oestradiol (1 nM) and IGF-I (2.5 nM) were added together, the combined effect on thymidine incorporation and cell number was significantly greater than additive. This synergistic effect on the IGF-I growth response was totally abolished by the IGF-I receptor antibody. The results suggest a cooperative interaction of oestradiol and IGF-I. It is concluded that growth stimulation of MCF-7 cells by long term treatment with oestradiol may be mediated through autocrine secretion of IGF-I. the effect of short term stimulation of thymidine incorporation suggest that the growth response of oestradiol is more complex, and indicate that a cooperative interaction with IGF-I is involved, which is unrelated to stimulated autocrine secretion.
J Steroid Biochem
Mol
Biol 1992 Mar
PMID:Oestradiol treatment increases the sensitivity of MCF-7 cells for the growth stimulatory effect of IGF-I. 156 24
We have studied the effects of various steroids on DNA synthesis in MCF-7 human breast carcinoma cells, which have aromatase activity and which exert an oestrogen receptor-mediated growth, to assess the significance of intracellular aromatase on growth stimulation as well as inhibition by aromatase inhibitors. The cells were cultured for 96 h in
phenol
red-free medium containing 10% charcoal-treated fetal bovine serum and test reagents and pulse-labelled with [3H]thymidine. Physiological concentrations of oestradiol, oestrone, testosterone (T) and androstenedione (AD) stimulated thymidine incorporation. However, oestrone-sulphate and dihydrotestosterone (DHT) only stimulated at concentrations greater than the physiological levels. T and DHT stimulation was blocked by tamoxifen, but not by cyproterone acetate, suggesting that the stimulation was mediated via the oestrogen receptor but not by the androgen receptor. Stimulation by T and AD was reduced by aminoglutethimide and 14 alpha-hydroxy-4-androstene-3,6,17-trione, both of which inhibit aromatase activity, however, stimulation by nonaromatizable DHT was not reduced by the inhibitors, suggesting that androgens were converted by the intracellular aromatase to oestrogens which stimulated the thymidine incorporation. It is suggested that intracellular aromatase significantly contributes to the stimulation of DNA synthesis and that aromatase inhibitors suppress the stimulation.
J Steroid Biochem
Mol
Biol 1992 May
PMID:Contribution of aromatase to the deoxyribonucleic acid synthesis of MCF-7 human breast cancer cells and its suppression by aromatase inhibitors. 160 40
Phenol red, commonly used as a pH indicator in tissue culture media, is known to possess estrogenic properties. We investigated the effect of
phenol
red on the process of thyroglobulin iodination which occurs only at the apical surface of porcine thyroid cells when cultured in porous bottom chambers. When
phenol
red was added simultaneously to both compartments (apical and basolateral), separated by the polarized monolayer, thyroglobulin iodination was inhibited by about 86% without any effect on thyroglobulin secretion and apical iodine concentration. When
phenol
red was added separately to either the apical or basal media, inhibition was 68% and 43%, respectively. A large amount of
phenol
red which was introduced into the basal medium crossed through the monolayer. Thus, inhibition was dependent upon the concentration of
phenol
red present in the apical compartment. A maximal inhibition was observed from 30 microM apical concentration. Phenol red acts as a substrate for thyroperoxidase in the iodination reaction.
Mol
Cell Endocrinol 1991 Oct
PMID:Phenol red: an inhibitor of thyroglobulin iodination in cultured porcine thyroid cells. 166 28
Neurodegenerative diseases are characterized by neuronal degeneration of specific neurons, e.g., degeneration of motoneurons in amyotrophic lateral sclerosis. As an approach to understand molecular mechanisms of neuronal degeneration of human spinal cord motoneurons in various motor neuron diseases, we have constructed a human spinal cord cDNA library and developed a strategy for isolating spinal cord-specific genes by subtractive cloning. We constructed human spinal cord and brain cDNA libraries from postmortem human spinal cord and brain. To isolate human spinal cord-specific cDNAs, a spinal cord-enriched [32P]cDNA probe was generated by the
phenol
emulsion reassociation technique. Forty-eight cDNA clones out of 10,000 colonies gave strong signals with the subtracted probe, and individual spinal cord cDNA clones were isolated. Northern blotting analysis confirmed that two spinal cord cDNA clones are, in fact, more abundant in spinal cord compared to brain.
J
Mol
Neurosci 1991
PMID:Construction of spinal cord cDNA library and application for subtractive cloning of spinal cord-specific cDNAs. 168 56
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