Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

High performance liquid chromatography using PMSS-C18 resin was applied to separate variant-complicated histone H1 from liver of a Baikal lake endemic fish sand sculpin (Cottus Kessleri Dybow). Total H1 was resolved into 3 main fractions. One of them was resolved into two sub-fractions by rechromatography. All the fractions and sub-fractions obtained were studied for their amino acid composition. One of the subfractions (H1(3] contained no tyrosine residues, but very much (20%) proline. Hence, this subfraction may be a new type of lysine-rich histone H1.
Mol Biol (Mosk)
PMID:[Use of high performance liquid chromatography for analysis of subfractions of lysine-rich histone H1 from Baikal fish--the sand sculpin Cottus kessleri Dyb]. 212 47

Platelet-activating factor (PAF) is a potent contractile agonist in guinea pig peripheral lung strips. Whether PAF acts via specific receptor sites in the lung has not been fully established. To determine if specific receptor sites could be demonstrated in guinea pig peripheral lung tissue, we performed direct radioligand binding studies in tissue homogenates with [3H]C16-PAF (1-O-hexadecyl-sn-glyceryl-3-phosphorylcholine) and the PAF antagonists [3H]WEB 2086 and [3H]RP52770. These studies demonstrated binding sites for [3H]C16-PAF of high affinity (Kd of 2.6 nM from saturation isotherms and 0.9 nM from kinetic experiments) and a mean density of 200 fmol/mg protein. Binding was inhibited to the same degree with unlabeled C16-PAF, WEB 2086, and RP52770, all with pseudo-Hill slopes of unity. [3H]WEB 2086 binding demonstrated a receptor density similar to that of [3H]C16-PAF (226 fmol/mg protein) and was inhibited to the same degree by unlabeled C16-PAF, C18-PAF, WEB 2086, and RP52770. Although antagonist inhibition yielded pseudo-Hill slopes near unity, agonist inhibition slopes were shallow, suggesting two types or states for the PAF receptors. Direct binding studies with [3H]RP52770 revealed a much larger density of binding sites (1,200 fmol/mg protein), and this binding was not inhibited with C16-PAF, C18-PAF, WEB 2086, or lyso-PAF. These results indicate that guinea pig lung has specific binding sites for [3H]C16-PAF, that WEB 2086 is an effective antagonist of C16- and C18-PAF binding at these sites, and that RP52770 binds to the PAF site but, in addition, binds to another site with a much greater density.
Am J Respir Cell Mol Biol 1990 Sep
PMID:Characterization of receptors for platelet-activating factor in guinea pig lung membranes. 216

Monohexosylceramides of Echinococcus multilocularis metacestodes have been isolated and analyzed by thin-layer chromatography, gas-liquid chromatography and mass spectrometry. 90.9% of the parasite fraction was galactosylceramide; glucosylceramide was present at only 9.1%. The most important fatty acids were normal C16:0 and C26:0 fatty acids. The hydroxylated fatty acids of the ceramide part constituted 20.1% of the total, their major constituents were C18:0 and C26:0. The sphinganine accounted for 70.4% of long-chain bases, phytosphingosine and sphingosine were also detected. The importance of the long chain fatty acids and the presence of sphinganine in the monohexosylceramide fraction were discussed.
Mol Biochem Parasitol 1990 Jun
PMID:Analysis of the monohexosylceramide fraction of Echinococcus multilocularis metacestodes. 238 63

A clonal cell line (56-42) that was stably and exclusively resistant to the toxic effects of the antileukemic agent 5-aza-2'-deoxycytidine (5-aza-CdR) was derived from C3H 10T1/2 C18 cells after multiple treatments with 5-aza-CdR. The 50% lethal dose of 5-aza-CdR for these cells was 1.3 microM, which was 15-fold greater than that for the parental cells. Cell line 56-42 was slightly cross-resistant to the ribo-analog 5-azacytidine, but was sensitive to the nucleoside analog 1-beta-D-arabinofuranosylcytosine and to colcemid. Both parental and resistant cell lines incorporated equimolar amounts of 5-aza-CdR into DNA. Resistance was therefore not due to decreased activation, increased detoxification, or reduced incorporation of the drug. The overall level of cytosine methylation in the resistant clone was 80% lower than the level in the sensitive cells. Therefore, the potential number of hemimethylated sites created by the incorporation of equivalent amounts of 5-aza-CdR into the DNA of the two cell types was much greater in the sensitive cells. Furthermore, 5-azacytosine-substituted DNA from the sensitive cells bound 100% more nuclear protein in the form of highly stable complexes. The incorporation of 5-aza-CdR opposite methylated cytosine residues in DNA of the sensitive cells thus resulted in increased nuclear protein binding at hemimethylated sites. This relative increase in tight-binding protein complexes was shown to occur in living cells and may well disrupt replication and transcription and instigate cell death. The differential binding of proteins to hypomethylated, azacytosine-containing DNA may thus mediate a novel mechanism of drug resistance.
Mol Cell Biol 1987 Sep
PMID:Differential nuclear protein binding to 5-azacytosine-containing DNA as a potential mechanism for 5-aza-2'-deoxycytidine resistance. 244 74

Three developmentally determined myogenic cell lines derived from C3H 10T1/2 C18 (10T1/2) mouse embryo cells treated with 5-azacytidine were compared with the parental 10T1/2 line for their susceptibility to oncogenic transformation by 3-methylcholanthrene or the activated human c-Ha-ras oncogene. Neither the 10T1/2 cells nor the myogenic derivatives grew in soft agar or formed tumors in nude mice. In contrast to 10T1/2 cells, the three myogenic derivatives were not susceptible to transformation by 3-methylcholanthrene, so that cellular determination altered the response of 10T1/2 cells to chemical carcinogen. On the other hand, all cell types were transformed to a tumorigenic phenotype following transfection with the activated c-Ha-ras gene. The transfected myogenic cells expressed both the c-Ha-ras gene and the muscle determination gene MyoD1. In contrast to other reports, the presence of as many as six copies of the c-Ha-ras gene per genome did not prevent the formation of striated muscle cells which expressed immunologically detectable muscle-specific myosin. The expression of the c-Ha-ras gene does not therefore necessarily preclude the expression of the determination gene for myogenesis or prevent end-stage myogenic differentiation.
Mol Cell Biol 1988 Oct
PMID:Effect of cellular determination on oncogenic transformation by chemicals and oncogenes. 246 Jul 42

In previous work, three clonal cell lines with extremely low DNA methylation levels were derived by multiple consecutive treatments of C3H 10T1/2 C18 (10T1/2) cells with 5-aza-2'-deoxycytidine (5-aza-CdR). In this study we examined the methylation status of genes in these three methyl-deficient clones to assess the specificity of the induced hypomethylation. Complete demethylation of virtually all 5'-CCGG-3' sites was observed in four genes examined, but some sites common to all three clones were persistently methylated even after further exhaustive 5-aza-CdR treatment. Thus, there is a subset of methylation sites within these cells which can never be stably demethylated. The extensive demethylation was not always associated with changes in the level of RNA expression of the genes examined but was strongly correlated with an altered chromatin structure of the unexpressed alpha 1-globin gene and the muscle determination gene MyoD1. These results provide a direct correlation between hypomethylation and the induction of a transcriptionally competent chromatin state.
Mol Cell Biol 1989 Mar
PMID:Gene structure and transcription in mouse cells with extensively demethylated DNA. 247 Oct 61

Prior studies demonstrated far greater amounts of lipid peroxidation (LP) in mitochondria from the zona reticularis (inner zone) of the guinea pig adrenal cortex than in mitochondria from the outer zone (zona fasciculata + zona glomerulosa) of the gland. alpha-Tocopherol concentrations, by contrast, were greater in the outer zone. To determine if the differences in alpha-tocopherol content were responsible for the regional differences in LP, the effects of alpha-tocopherol deficiency on mitochondrial LP were investigated. Tocopherol deficiency had relatively little effect on ferrous ion- or ascorbic acid-induced LP in inner zone mitochondria. However, depletion of adrenal tocopherol substantially increased outer zone LP, eliminating the differences between the two zones. Fatty acid analyses revealed that mitochondria from tocopherol-deficient animals contained significantly less linoleic acid (C18:2) and arachidonic acid (C20:4) than those from controls, suggesting peroxidative losses in vivo. In mitochondria from control animals, subphysiological concentrations of ascorbic acid stimulated LP, but physiological levels did not. However, in tocopherol-depleted mitochondria, even physiological concentrations of ascorbic acid stimulated LP. The results indicate that the intra-adrenal distribution of alpha-tocopherol is responsible for the regional differences in mitochondrial LP and that alpha-tocopherol is a major determinant of ascorbic acid actions on adrenal LP. The data also provide evidence of adrenal LP in vivo in tocopherol-deficient animals.
Mol Cell Endocrinol 1989 Apr
PMID:alpha-Tocopherol depletion eliminates the regional differences in adrenal mitochondrial lipid peroxidation. 274 27

Analysis of bovine follicular fluid (FF) using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) coupled with a sensitive immunoblotting procedure resolved several components that were immunoreactive with an antiserum directed against the n-terminus of the alpha subunit of human inhibin (hI alpha(1-32]. Under non-reducing conditions, three intensely stained bands having apparent Mr values of 116,000, 44,000 and 25,000 were present, whilst under reducing conditions only two intensely stained bands (Mr 43,000 and 21,000) were detected. The Mr 44,000 and 25,000 immunoreactive forms (non-reducing conditions) were also demonstrated in bovine utero-ovarian vein and peripheral venous plasma after subjecting samples (40 ml) to immunoaffinity concentration using Sepharose beads coupled to anti-hI alpha(1-32), SDS-PAGE and immunoblotting. The same approach revealed the presence of the smaller (Mr 25,000) form in bovine granulosa cell-conditioned culture medium (GCCM). Gel-permeation chromatography (Sephacryl S-200), immunoaffinity chromatography (Sepharose-anti-hI alpha(1-32] and reversed-phase high-performance liquid chromatography (RP-HPLC; C18 and C8 columns) were employed to isolate from bFF (30 ml, 19.5 g protein) 750 micrograms protein which appeared essentially homogeneous by RP-HPLC and SDS-PAGE and had an Mr of 25,000 (non-reducing conditions)/21,000 (reducing conditions), identical to that of the immunoreactive component of lowest Mr found in bovine FF, utero-ovarian vein plasma, peripheral plasma and GCCM. The isolated material was highly immunoreactive with antisera against both hI alpha(1-32) and purified Mr 32,000 bovine inhibin but was devoid of biological activity when tested in a rat pituitary cell inhibin bioassay. Amino-terminal analysis revealed an amino acid sequence (residues 1-14) identical to that reported elsewhere for the alpha subunit (Mr 20,000/21,000) of bovine inhibin. In conclusion, the present study has revealed that the bovine ovary secretes considerable quantities of monomeric inhibin alpha subunit. The unexpected presence of this material in peripheral blood is likely to hinder attempts to obtain physiologically relevant data on circulating levels of inhibin in cattle using conventional radioimmunoassays.
J Mol Endocrinol 1989 May
PMID:Evidence that the bovine ovary secretes large amounts of monomeric inhibin alpha subunit and its isolation from bovine follicular fluid. 275 27

Thiastearic acid positional isomers (8, 9, 10, 11) were examined for their ability to inhibit population growth and the biosynthesis of a phosphatidylethanolamine cyclopropane fatty acyl group, cis-9,10-methyleneoctadecanoic acid (dihydrosterculic acid), by promastigotes of Leishmania species. Thiastearic acids are candidate chemotherapeutic agents, since cyclopropane fatty acids are not formed by vertebrate cells. 8- and 10-thiastearic acids strongly inhibited the growth of strains containing the most dihydrosterculic acid (Leishmania tropica and Leishmania donovani; 25-35% phosphatidylethanolamine fatty acyl groups) and less strongly inhibited strains containing no dihydrosterculic acid (Leishmania major). The 11-thiastearic acid was less effective and 9-thiastearic acid ineffective. Strains containing 1-15% dihydrosterculic acid (L. donovani, Leishmania braziliensis, Leishmania aethiopica and Leishmania mexicana mexicana) were with few exceptions not inhibited by any of the isomers. All the thiastearic acid isomers caused a dose-dependent loss of dihydrosterculic acid. This was accompanied by a loss of phosphatidylethanolamine in the case of dihydrosterculic acid-rich leishmanial strains exposed to the 8- and 10-isomers. The 8- and 10-thiastearic acids also caused a loss of C18 unsaturated fatty acyl groups and increases in palmitic and stearic acids in the phosphatidylethanolamine and phosphatidylcholine of the dihydrosterculic acid-rich and dihydrosterculic acid-free leishmanial strains. 11-Thiastearic acid was much less effective and 9-thiastearic acid ineffective. These changes were not evident in those strins which contained 1-15% dihydrosterculic acid and whose growth was not inhibited by the thiastearic acid isomers. It is concluded that thiastearic acid isomers may inhibit both dihydrosterculic acid biosynthesis and fatty acid desaturation, with the 9-isomer having the highest specificity for dihydrosterculic acid biosynthesis. Population growth of promastigotes of Leishmania species in culture is not dependent upon dihydrosterculic acid biosynthesis but is dependent upon fatty acid desaturation.
Mol Biochem Parasitol 1989 Jun 01
PMID:Effects of thiastearic acids on growth and on dihydrosterculic acid and other phospholipid fatty acyl groups of Leishmania promastigotes. 276 73

Rabbit peripheral serum and uterine tissue (embryonic (EZ) and interembryonic (IEZ) zones) were assayed for the main C21, C19 and C18 steroids throughout pregnancy and pseudopregnancy (PSPG). Pregnenolone concentrations in PSPG and IEZ were comparable and remained relatively stable, while its level in EZ increased, reaching a peak value of 18.2 +/- 0.8 ng/g by day 15, and decreasing thereafter to a level comparable to oestrus by day 25. Tissue concentrations of progesterone were comparable in PSPG and IEZ, reached their maximal level on days 6.5 and 9, and decreased significantly (P less than 0.01) on day 15. In EZ, progesterone level was significantly lower than in IEZ and decreased on day 9 compared to day 6.5. A further decrease was observed from days 9 to 15 but no difference between tissues was observed on the latter day. Thus, the blastocyst-foetus exerts a local effect by decreasing progesterone content and increasing pregnenolone level in the uterine tissue adjacent to its implantation (EZ). The conversion of progesterone in uterine tissue to less-active metabolites does not appear to occur towards the C19 and C18 steroids.
Mol Cell Endocrinol 1989 Jul
PMID:Local effect of the rabbit embryo-foetus on uterine progesterone and pregnenolone levels. 279 65


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