Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: KEGG:D06522 (Silica)
 2,396 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A sensitive and convenient radioassay for the in vitro determination of ethylmorphine N-demethylase and O-de-ethylase activity has been developed. Ethylmorphine[6-3H] was prepared by reduction of the corresponding morphinone in nearly quantitative yield. After incubation with hepatic microsomes from male rats, the reaction was terminated by the addition of 5 ml of acetone. The sample was saturated with potassium acetate and extracted twice with acetone giving complete extraction of the radiolabeled ethylmorphine and its metabolites. After the combined organic phases were evaporated, the samples were dissolved in methanol and applied to a Silica Gel GF plate with subsequent development in ethyl acetate-methanol-concentrated NH4OH. The amount of radioactivity detected for the morphine and norethylmorphine bands at zero time was approximately 0.05% of the original amount of labeled ethylmorphine added to the incubation media. Similarly, the Km values were 52 and 250 microns for the O- and N-dealkylation respectively, while the Vmax values were 5.0 and 1.8 nmol/mg of protein per min. Finally, with this assay we have observed constant specific activity for both the N- and O-dealkylation of ethylmorphine[6-3H] with as little as 10 micrograms of microsomal protein per ml of incubation media.
 ...
PMID:Studies on the N-demethylation and O-de-ethylation of ethylmorphine[6-3H] by male rat hepatic microsomes. 49 Mar 20

A known analytical procedure was used for increasing the sensitivity threshold of the reaction of the zone opening on chromatogrammes. The procedure was the following: the carboxylic acid admixtures determined chromatographically were previously extracted from dry samples of the test-compounds into an optimal solvent. The expediency of the procedure was shown on examples of phenylacetic, phenoxyacetic and isoxasolcarboxylic acids present as admixtures in semisynthetic penicillins and raw materials used for their preparation. The threshold sensitivity was increased by 6 to 9 times. The chromatographic separation was performed in a fixed layer of Silica Gel KSK treated with a buffer. The mobile phase was used in the form of a solvent system: n-heptan-glacial acetic acid (95:5).
 ...
PMID:[Increasing the threshold sensitivity of the spot detection reaction on a chromatogram]. 81 50

An effective resolution of intact phosphatidylserines on the basis of unsaturation has been achieved by conventional argentation thin layer chromatography (TLC) following trifluoracetylaction. The trifluoroacetamides are prepared by treatment with trifluoroacetic anhydride or N-methyl-bis-trifluoroacetamide. The acetamides are resolved with chloroform-methanol-water (65:25:4, v/v/v) on Silica Gel G containing 20% silver nitrate. Subfractions with 0-6 double bonds per molecule were obtained for the phosphatidylserines of pig and ox brain, pig erythrocytes, rat liver, and rabbit skeletal muscle. The preparation of trifluoroacetamides is also advantageous for the silver ion fractionation of phosphatidylethanolamines. The method is applicable to metabolic studies of molecular species using radioactive precursors of neutral lipids, phosphorus, and nitrogenous bases.
 ...
PMID:Resolution of molecular species of intact serine and ethanolamine phosphatides by argentation chromatography of their trifluoroacetamides. 89

A fucosylceramide was isolated from a ceramide monohexoside fraction of human colon carcinomas by acetylation followed by preparative thin layer chromatography on Silica Gel G developed with butylacetate. It contained only fucose as the carbohydrate component and the ceramide moiety was characterized as N-palmitoyloctadecasphingenine as a predominant component. The structure of the compound was determined as alpha-L-fucopyranosylceramide by methylation analysis, mass spectrometry of permethylated and reduced glycolipid, and by enzymatic hydrolysis with alpha-L-fucosidase. The chemical concentration of this compound in colon tumor tissue depends on degree of malignancy: highly malignant metastatic deposits from colon cancers were 3 to 70 ng/mg of residue protein, whereas that of localized colon tumor was 0 to 2 ng/mg of protein residue. The present observation offers additional support for the occurrence of metabolic abnormality of fucolipids as membrane phenotype of malignancy as was suggested in previous studies (Yang, H-J., and Hakomori, S. (1971) J. Biol. Chem. 246, 1192-1200; Steiner, S., Brennan, P.J., Melnick, J. L. (1973) Nature New Biol. 245, 19-21).
 ...
PMID:alpha-L-Fucopyranosylceramide, a novel glycolipid accumulated in some of the human colon tumors. 126 28

This paper studies the advances that have participated in the development of preservation solutions for the combined kidney-pancreas transplantation. These developments have been associated most importantly with hypothermia, the use of colloid solutions with high oncotic pressure, and the maintenance of near-intracellular ionic concentration. At the present time, the more effective solutions are the plasma-like modified Silica Gel Fraction and the starch and lactobionate based solution such as, the UW. Further advances in this area, would allow for improved results in the combined kidney-pancreas transplant preparation.
 ...
PMID:[Preservation of the pancreas for the simultaneous transplantation of kidney-pancreas]. 130 92

Pannorin, a naphthopyrone that inhibits 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate-limiting enzyme in cholesterol synthesis, was isolated from a culture broth of Chrysosporium pannorum M10539 by solvent extraction, Bio-Gel P-6 column chromatography and reverse phase HPLC (Silica ODS). Spectroscopic analyses of the compound yielded 4,8,10-trihydroxy-5-methyl-2H-naphtho[1,2-b]pyran-2-one as the proposed structure. Pannorin inhibited HMG-CoA reductase and in vitro sterol synthesis 50% at a concentration of 160 microM.
 ...
PMID:Pannorin, a new 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor produced by Chrysosporium pannorum. 188 66

The fprA gene is immediately adjacent to the csgA gene (formerly known as spoC) of Myxococcus xanthus. Whereas the csgA gene has an essential role in cell interactions during the developmental cycle, the function of the fprA gene is unknown. Gene disruption was used to determine what affect a null mutation in this gene has on the phenotype of the cell. A csgA-fprA deletion and an fprA frameshift mutation were constructed in vitro in a cloned copy of this locus and then inserted into the M. xanthus chromosome to create a merodiploid with the wild-type and mutant alleles in tandem. The merodiploid was then allowed to segregate one of the two alleles along with the vector sequences in an effort to replace the wild-type allele with the mutant allele. All of the segregants had the wild-type allele, suggesting that a functional fprA gene is essential for vegetative growth. The fprA gene was placed under control of the lacZ transcriptional and translational signals and overexpressed in Escherichia coli, and the new host was examined for any phenotypic changes. A 27-kilodalton protein was observed in sodium dodecyl sulfate-polyacrylamide gels of total-cell protein as predicted from the DNA sequence of this gene. Overexpression of FprA caused the accumulation of a yellow pigment with spectral and redox properties similar to that of the flavins. The pigment cochromatographed with flavin mononucleotide by Silica Gel G thin-layer chromatography. Approximately two-thirds of the total cellular flavin was associated with soluble protein. The major soluble flavin-associated protein was purified on DEAE-Bio-Gel A and Phenyl-Sepharose CL-4B and by polyacrylamide gel electrophoresis. The amino acid composition of the purified protein was similar to that predicted from the DNA sequence of the FprA fusion protein. Apparently, overproduction of FprA (for flavin-associated protein A) in E. coli resulted in a large increase in flavin biosynthesis. Together, these results suggest that the fprA gene encodes a protein that is associated with flavin mononucleotide and has an essential function in M. xanthus.
 ...
PMID:The Myxococcus xanthus FprA protein causes increased flavin biosynthesis in Escherichia coli. 215 2

1. Subcellular fractions isolated from livers of 19-day-old chicken embryos were analyzed in order to assess whether liver mitochondria contained glycosylated proteins or had mannosyl- or sialyl-transferases that could transfer sugars to mitochondrial macromolecules. 2. Proteins in liver mitochondrial membranes and matrix fractions were screened for their affinities for concanavalin A (Con A). 3. After separation by gel electrophoresis under denaturing conditions, a significant number of the proteins bound [125I]Con A, and the binding of the lectin was substantially inhibited by alpha-methyl-D-mannoside. 4. In addition, radio-iodinated matrix proteins were screened for lectin-binding properties by chromatography on Con A covalently linked to agarose. 5. A number of proteins, representing 14% of those loaded onto the column, became tightly bound to the agarose-linked lectin, and the molecular weights of several of those proteins are reported. 6. Mannosyltransferase activities were measured in fractions highly enriched for mitochondria. 7. In the reactions, mannose was transferred from guanosine diphosphomannose to materials insoluble in 0.3% trichloroacetic acid or in chloroform:methanol (2:1). 8. The fractions also catalyzed the transfer of mannose to materials extractable in chloroform:methanol and which migrated with the Rf of dolichol phosphate on Silica Gel H. 9. Dolichol phosphate stimulated the transfer of mannose to those materials extractable in the organic solvents. 10. Marker enzyme analyses indicated that the mannosyl transferase activity in the mitochondrial fraction could not be accounted for entirely by contaminating microsomal membranes. 11. Although sialyltransferase activity was detected also in the mitochondrial fractions, the levels of the activity and the kinetics of the reactions indicated that Golgi membranes were most likely the sources of the enzyme.
 ...
PMID:Mitochondrial biogenesis: do liver mitochondria contain glycoproteins and glycosyltransferases? 228 16

The tricarboxylate carrier of bovine liver mitochondria has been solubilized by Triton X-114 and purified by chromatography on hydroxylapatite and Silica Gel 60. The purified carrier could be visualized as a single band in polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate with Mr 37,000-38,000. The carrier, after reconstitution in phospholipid vesicles, catalyzed the exchange of [14C]citrate against citrate, malate, and threo-D8-isocitrate and was inhibited by the specific tricarboxylate carrier inhibitor 1,2,3-benzenetricarboxylic acid.
 ...
PMID:Tricarboxylate carrier of bovine liver mitochondria. Purification and reconstitution. 254 27

A rapid spectrodensitometric method for the determination of Piroxicam and its impurities is described. The procedure involves a HPTLC separation on Silica Gel F254 plates. Quantitative determinations are carried out using a spectrodensitometer at 310 nm. The proposed method is sensitive and the minimum amount detectable of Piroxicam impurities is around 10 ng.
 ...
PMID:Quantitative determination of Piroxicam and its impurities by HPTLC spectrodensitometry. 272 89


1 2 3 4 5 6 Next >>