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11.
Dye sensitized photo-oxidation inactivates tyrosinases isolated from Neurospora and Agaricus. The rate of inactivation is enhanced by cyanide and is dependent on pH. 相似文献
12.
G J Howlett P W Dickson H Birch G Schreiber 《Archives of biochemistry and biophysics》1982,215(1):309-318
The molecular weights of a number of 125I-labeled plasma proteins have been determined from an analysis of their sedimentation equilibrium behavior in an air-driven ultracentrifuge. The values obtained agree well with results obtained by other methods. Molecular weights obtained for 125I-labeled bovine serum albumin and the rat serum proteins albumin, α1-acid glycoprotein, and major acute-phase α1-protein were unaffected by the addition of 7% rat plasma. Direct evidence for protein-protein interactions was obtained for mixtures of 125I-labeled rat α1-acid glycoprotein and the plant lectin concanavalin A and for mixtures of 125I-labeled protein A from Staphylococcus aureus and 7% rat plasma. Interactions of a different type were observed when the sedimentation equilibrium profiles of 125I-labeled proteins were determined in concentrated solutions of other proteins. Under these conditions the effects of molecular exclusion or nonideality became significant and low estimates were obtained for the molecular weights of the labeled proteins. Analysis of the data obtained for 125I-labeled bovine serum albumin in concentrated solutions of bovine serum albumin (20–80 mg/ ml) yielded nonideality coefficients in good agreement with literature values. Analysis of the behavior of 125I-labeled rat serum albumin, transferrin, and α1-acid glycoprotein yielded nonideality coefficients and hence activities of these proteins in undiluted rat plasma. 相似文献
13.
Microautoradiography of water-soluble compounds in plant tissue after freeze-drying and pressure infiltration with epoxy resin 下载免费PDF全文
It is difficult to retain and localize radioactive, water-soluble compounds within plant cells. Existing techniques retain water-soluble compounds with varying rates of efficiency and are limited to processing only a few samples at one time. We developed a modified pressure infiltration technique for the preparation of microautoradiographs of 14C-labeled, water-soluble compounds in plant tissue. Samples from cottonwood (Populus deltoides Bartr. ex Marsh.) labeled with 14C were excised, quick frozen in liquid N2, freeze-dried at −50°C, and pressure-infiltrated with epoxy resin without intermediate solvents or prolonged incubation times. The technique facilitates the mass processing of samples for microautoradiography, gives good cellular retention of labeled water-soluble compounds, and is highly reproducible. 相似文献
14.
The effects of Meloidogyne incognita or M. javanica at five initial inoculum levels of 20, 100, 200, 1,000, and 2,000 eggs and infective juveniles per seedling on ''Floradade,'' ''Nemarex,'' ''Patriot,'' and ''PI 129149-2(sib)-5'' tomatoes maintained at 25 or 32.5 C were studied. The number of egg masses on roots of the susceptible cultivar Floradade was similar for both species of root-knot nematodes at either 2.5 or 32.5 C soil temperatures. At 25 C, very low numbers of egg masses were produced by both species of root-knot nematodes on Nematex, Patriot, and Lycopersicon peruvianum PI 129149-2(sib)-5. At 32.5 C, the best inoculum level for assessing resistance in these tomato genotypes was 200 eggs and infective juveniles per seedling. With 28 days of incubation, this temperature and inoculum level produced quantitative differences in resistance for both species of Meloidogyne. 相似文献
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16.
In chick bone collagen the degree of lysine hydroxylation and the magnitude of the crosslink ratio dihydroxylysinonorleucine/hydroxylysinonorleucine were both found to be inversely related to the concentration of plasma calcium. Lysine hydroxylation was also affected by a second factor related to vitamin D status. 相似文献
17.
The mouse int-2 gene exhibits basic fibroblast growth factor activity in a basic fibroblast growth factor-responsive cell line 总被引:2,自引:0,他引:2
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19.
Karmella A Haynes Marian L Broderick Adam D Brown Trevor L Butner James O Dickson W Lance Harden Lane H Heard Eric L Jessen Kelly J Malloy Brad J Ogden Sabriya Rosemond Samantha Simpson Erin Zwack A Malcolm Campbell Todd T Eckdahl Laurie J Heyer Jeffrey L Poet 《Journal of biological engineering》2008,2(1):1-12
20.
Neuronal process outgrowth of human sensory neurons on monolayers of cells transfected with cDNAs for five human N-CAM isoforms 总被引:7,自引:7,他引:7 下载免费PDF全文
P Doherty C H Barton G Dickson P Seaton L H Rowett S E Moore H J Gower F S Walsh 《The Journal of cell biology》1989,109(2):789-798
Full length cDNAs for a variety of human N-CAM isoforms have been transfected into mouse L-cells and/or 3T3 cells. Three independent clones of each cell line that were shown to express human N-CAM were tested for their ability to support the morphological differentiation of sensory neurons. The cell surface expression of N-CAM isoforms, linked to the membrane directly by an integral transmembrane spanning domain or indirectly via covalent attachment to a glycosyl-phosphatidylinositol moiety, were consistently found to be associated with a significant increase in the morphological differentiation of both human and rat dorsal root ganglion neurons. Modification of the extracellular structure of both classes of N-CAM, consequent to the expression of a glycosylated 37-amino acid sequence normally found expressed exclusively in muscle N-CAM isoforms did not obviously affect the ability of transfected cells to support increased neuronal differentiation. 3T3 cells that were transfected with a full length cDNA encoding a secreted N-CAM isoform, and that have previously been shown to secrete N-CAM into the growth media rather than link it to the membrane did not significantly differ from control cells in their ability to support neuronal differentiation. These data provide direct evidence for both transmembrane and lipid-linked N-CAM isoforms being components of the regulatory machinery that determines neuronal morphology and process outgrowth. 相似文献