Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A nuclear p53/55 protein kinase has been isolated from nuclear ribonucleoprotein particles from human tumor cells. The enzyme was purified approximately 2200-fold cell nuclei by sequential ribonuclease digestion of the RNP particles, DEAE cellulose and phosphocellulose chromatography. The kinase which was cAMP independent, catalyzed the phosphorylation of rabbit muscle glycogen synthase in the amino terminal domain, and conversion of the I to D form. The D synthase had a phosphorylation stoichiometry of 8 moles 32P per mole of synthase subunit with maximal specificity for ATP as phosphate donor; its Km was 30 microM. An antinucleolar antibody inhibited enzyme activity by 80%. Substrates for most other kinases were inactive. The kinase was essentially unaffected by the Walsh inhibitor, EGTA, regulatory subunits of protein kinase, calmodulin, trifluoperazine or heparin. Its activity was lost at 1 mM polyamine, but was enhanced 3-fold by MnCl2 and 4- to 9-fold by deoxymononucleotides. The nuclei of HeLa cells contained 64% of the total kinase of which 64% of the total kinase of which 11% were in nucleoli; the specific activity of the nucleolar kinase was twice that of the nuclear supernatant and four times that of the cytoplasmic kinase. These results indicate that nucleolar ribonucleoprotein particles of human tumor cells contain a cAMP-independent protein kinase which is similar to glycogen synthase kinase.
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PMID:Purification of p53/55 kinase from nuclear ribonucleoproteins of Namalwa cells. 643 81

In cultured melanotic melanoma, a marked decrease of pigmentation has been found to be induced by the addition of tunicamycin [Y. Mishima and G. Imokawa (1983) J. Invest. Dermatol. 81, 106-114]. Since it appears that this impaired pigmentation arises from the loss of asparagine-linked sugar chains serving as a signal for transport of tyrosinase from GERL (Golgi-associated endoplasmic reticulum of lysosomes) to premelanosomes, tyrosinases from the membrane fraction of Greene's hamster melanoma have been purified, and the structures of their sugar chains have been analyzed. Two kinds of tyrosinases were purified by Triton X-100 solubilization; DEAE-cellulose, Sephadex G-200, and DEAE-Sephadex column chromatography; and preparative polyacrylamide gel electrophoresis. The two tyrosinases were separated by polyacrylamide gel electrophoresis, and both corresponded to Mr 69,000. Their asparagine-linked sugar chains were released by hydrazinolysis and analyzed. The sugar chains of the two tyrosinases were identical except for the sialic acid contents. One mole of each tyrosinase contained 1 mol of high-mannose-type sugar chains and 3 mol of complex-type sugar chains. The former chain has Man3 approximately 5 X GlcNAc2 and the latter has Man3 X GlcNAc beta 1----4(+/- Fuc alpha 1----6)GlcNAc as their core structures. The complex-type sugar chains are composed of mono-, bi-, tri-, and tetraantennary sugar chains, with +/- Sia alpha 2----3Gal beta 1----4GlcNAc beta 1----as their outer chains.
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PMID:Purification of hamster melanoma tyrosinases and structural studies of their asparagine-linked sugar chains. 643 39

Homozygous horse transferrin (Tf O) is highly heterogeneous. In starch gel electrophoresis it gives at least 9 zones. Two main components (2a and 4b) were purified by rivanol and ammonium sulphate precipitation, DEAE-Sephadex chromatography and SP-Sephadex chromatography. Molecular weights of 75 200 and 80 500 for components 2a and 4b, respectively, were determined by sedimentation equilibrium ultracentrifugation. Amino acid compositions of the two components were similar, and there were no differences in the N-terminus (glutamic acid followed by glutamine) and the C-terminus (valine). Differences were found in carbohydrate composition between components 2a and 4b. Component 2a contained 10 moles of sugar components per mole of protein (4 hexoses, 4 hexosamines and 2 sialic acids), while component 4b contained twice the number of both total carbohydrates and individual sugar components. Carbohydrates were identified as mannose and galactose (ratio mannose: galactose approximately equal to 1.5:1), N-acetylglucosamine and N-acetylneuraminic acid. At present it is not clear whether the difference between the two components resides solely in the difference of carbohydrate contents. It is proposed that component 2a has one diantennary glycan, while component 4b has two.
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PMID:Heterogeneity of horse transferrin: the role of carbohydrate moiety. 649 65

Glutamyl-tRNA synthetase has been isolated from an extreme thermophile, Thermus thermophilus HB8. The enzyme has been purified to homogeneity by successive chromatography on columns of DEAE-cellulose, DEAE-Sephacel, phosphocellulose and hydroxyapatite. 11.7 mg of purified enzyme has been obtained from 2 kg of T. thermophilus cells, with a purification factor of 600 with an 11% yield. From gel permeation chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis, the enzyme is found to be a monomer protein with a molecular weight of 50,000. The optimum temperature for the aminoacylation of T. thermophilus tRNAGlu is 65 degrees C, and the optimum pH range is 8.0-9.0, in the presence of 5 mM Mg2+. The Km values for ATP, L-glutamate, and T. thermophilus tRNAGlu are 230 microM, 70 microM, and 0.65 microM, respectively, in the presence of 50 mM KCl and 10 mM MgCl2 at pH 8.0 at 65 degrees C. Escherichia coli tRNA2Glu is also a good substrate with a Km value of 0.60 microM at 65 degrees C. The mole fractions of Arg and Leu residues are higher and that of Asx residues is lower than those of E. coli glutamyl-tRNA synthetase. Glutamyl-tRNA synthetase from T. thermophilus is remarkably thermostable; even after incubation for 9 h at 65 degrees C, 70% of the enzyme activity is retained in the absence of any protecting factors. Such an extremely thermostable enzyme with a low molecular weight will be useful for detailed physiochemical analyses on the molecular mechanism of strict recognition by aminoacyl-tRNA synthetases.
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PMID:Purification and characterization of glutamyl-tRNA synthetase from an extreme thermophile, Thermus thermophilus HB8. 652 23

We have evaluated the effects that methodology (incubation time, concentration of beef brain tubulin) have on the measurement of the interaction of tubulin with colchicine. The results show that, with DEAE filter paper assay, binding is maximal for 3 hr of incubation at 37 degrees C, and for low concentrations of tubulin (0.05 mg/ml). In these conditions binding constants determined with SCATCHARD plot are: constant of dissociation (KD) of complex tubulin-colchicine equal to 9.8 X 10(-7) M and stechiometry equal to 0.57 mole of colchicine bound for 1 mole of tubulin dimer. Competition of drugs with colchicine binding site may be evaluated with this methodology. IC50 and affinity constants (Ki) of podophyllotoxin, a competitive inhibitor of colchicine-binding determined with these experimental conditions were 1.3 X 10(-6) M and 1.1 X 10(-6) M, respectively.
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PMID:Binding of colchicine to beef brain tubulin: influence of methodology on binding constants. 653 Sep 6

The major gamma-carboxyglutamic acid-containing protein of rabbit cortical bone isolated and purified from near-neutral (pH 7.5) EDTA-extracts by DEAE-cellulose and Sephadex G 75 column chromatography had a molecular weight of about 5600 based on integral amino-acid composition; this was confirmed by high-performance liquid chromatography. The purified protein had high glutamic acid and aspartic-acid contents, two to three residues of gamma-carboxyglutamic acid per molecule and zero levels of serine, threonine, methionine, histidine and tryptophan. Equilibrium dialysis indicated that the protein has a weak affinity for calcium ions with a formation constant of 1515 M-1 at I 0.15, pH 7.5, 25 degrees C with a binding capacity of 2 mol calcium per mole protein.
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PMID:The small molecular weight, gamma-carboxyglutamic acid-containing protein of rabbit bone tissue. 659 60

A rapid procedure for the purification of L-methionine gamma-lyase from Pseudomonas putida ICR 3460 by DEAE- TOYOPEARL 650M and DEAE-Sephadex A-50 column chromatography is presented. The enzyme was purified with an average yield of 75% and showed about 10-fold higher specific activity than the enzyme from P. putida (= P. ovalis) IFO 3738 reported previously (H. Tanaka, N. Esaki , and K. Soda (1976) FEBS Lett. 66, 307-311). The present enzyme has a molecular weight of about 172,000 and consists of four subunits with identical molecular weights (43,000). It shows the typical absorption spectrum of pyridoxal enzyme with maxima at 278 and 420 nm, and contains 4 mol of pyridoxal 5'-phosphate per mole of enzyme. The enzyme has a multicatalytic function similar to the enzyme of P. putida IFO 3738 (K. Soda, H. Tanaka, and N. Esaki (1983) Trends Biochem. Sci. 8, 214-217).
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PMID:Purification of bacterial L-methionine gamma-lyase. 674 20

We have purified propionyl-CoA carboxylase from normal, postmortem human liver to homogeneity. The isolation procedure, which provided an approximately 3000-fold purification and an overall yield of 26%, employed initial centrifugation of a cetyltrimethylammonium bromide-treated homogenate, followed by sequential chromatographic separations using DEAE-cellulose, Blue Sepharose, and Bio-Gel A-1.5m. The native enzyme has a molecular weight of approximately 540,000 and is composed of nonidentical subunits (alpha and beta) of Mr = 72,000 and 56,000, respectively. When studied with analytical isoelectrofocusing techniques, it focuses as a single peak at pH 5.5. Each mole of native enzyme contains 4 mol of bound biotin, virtually all of which is found with the larger (alpha) subunit. The apparent Km values for ATP, propionyl-CoA, and bicarbonate are 0.08 mM, 0.29 mM, and 3.0 mM, respectively. The enzyme also catalyzes the carboxylation of acetyl-CoA and butyryl-CoA to a limited degree, but not that of crotonyl-CoA. Propionyl-CoA carboxylase is quite stable over a temperature range from -50--37 degrees C and over a pH range from 6.2 to 8.4. It has a broad pH optimum from pH 7.2 to 8.8. Limited proteolysis with trypsin results in slow, time-dependent deactivation of the enzyme with preferential cleavage of the smaller subunit. Antiserum prepared against the native enzyme is shown to be monospecific by immunodiffusion and immunoelectrophoresis.
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PMID:Isolation and characterization of propionyl-CoA carboxylase from normal human liver. Evidence for a protomeric tetramer of nonidentical subunits. 676 47

Glycolipids were isolated from human gastric cancer tissues and normal mucosae. Sulfogalactosylceramide, ganglioside and neutral glycolipid fractions were separated by DEAE-Sephadex and silica gel column chromatography. Sulfogalactosylceramide contents were higher in the cancer tissues than in the normal mucosae. Ganglioside contents showed considerable variations but in the cancer tissues in mole percentage of ganglioside GM3 was higher than in the normal mucosae. The cancer tissues contained more neutral glycolipids than normal tissues. Glycolipids of lacto-series, including fucolipids, were markedly increased in the cancer tissues. Blood group A-active glycolipids were found in the cancer tissues from two patients with blood group O but not found in the uninvolved tissue associated with the cancer tissue.
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PMID:The presence of blood group A-active glycolipids in cancer tissues from blood group O patients. 679 95

Two cytoplasmic cadmium-binding glycoproteins from the hepatopancreas of a whelk, Buccinum tenuissimum, were purified to homogeneity by Sephadex G-75 gel filtration and two DEAE-Sephadex A-25 chromatographies in the presence of 2-mercaptoethanol. These two cadmium-binding glycoproteins, termed FIIA and FIIB, each showed a single band after electrophoresis on 10% polyacrylamide gel at pH 8.9. The molecular weight of FIIA was estimated as 8000 and that of FIIB as 13000 by SDS-polyacrylamide gel electrophoresis. Based on molecular weights of 6500 and 11900 for the protein moiety of FIIA and FIIB, respectively, the total number of amino acid residues was 52 in the former and 94 in the latter. Three and two cysteine residues in FIIA and FIIB, respectively, were titratable with p-chloromercuribenzoate. FIIB also contained two more half-cystine residues. The sugar contents of FIIA and FIIB were about 20.5% and 8.7% by weight, respectively, consisting of galactose, mannose, fucose and amino sugar. The purified glycoproteins FIIA and FIIB contained about 0.6% and 1.0% cadmium by weight, respectively, and both showed strong metal-binding capacity, especially for cadmium, copper and mercury. The apparent cadmium dissociation constants for FIIA and FIIB after treatment with 2-mercaptoethanol were 7.3 X 10(-6) and 9.1 X 10(-7) M, respectively. Cadmium contents at saturation were nearly 6 and 8 gatom per mole for FIIA and FIIB, respectively.
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PMID:Purification and molecular properties of two cadmium-binding glycoproteins from the hepatopancreas of a whelk, Buccinum tenuissimum. 684 39


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