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81.
Erik Harms Nathan Gochman Jerry A. Schneider 《Biochemical and biophysical research communications》1981,99(3):830-836
Free (non-protein) amino acids were measured in whole rat liver and in unmodified lysosomes which were prepared from rat liver by the technique of free-flow electrophoresis. Significant intralysosomal pools of threonine, serine, valine, cystine, methionine, isoleucine, leucine, tyrosine, phenylalanine, lysine and arginine were found. No efflux occurred from rat liver lysosomes in isotonic buffered sucrose at 0°C, but all amino acids showed various degrees of efflux at 200 and 370. 相似文献
82.
Summary The histochemical characteristics of spontaneous hepatocellular neoplasms in mice of both sexes were examined and compared with those of hepatocellular neoplasms induced in female mice by administration of polycyclic aromatic hydrocarbon carcinogens as initiators with or without subsequent phenobarbitone treatment. Controls treated with phenobarbitone alone were also included. Spontaneous neoplasms in the livers of mice rendered siderotic by subcutaneous iron injection were deficient in cellular accumulation of stainable iron. Glucose-6-phosphatase activity was deficient in the majority of spontaneous and induced neoplasms. ATPase activity was increased in about half of spontaneous and carcinogen-induced neoplasms but all induced neoplasms in mice treated with phenobarbitone showed deficient activity. -Glutamyltransferase activity was present in very few of the spontaneous neoplasms or in the neoplasms induced in the absence of phenobarbitone administration. However, all induced neoplasms in the mice receiving phenobarbitone showed some degree of -glutamyltransferase activity together with deficient glucose-6-phosphatase and ATPase activities. It is concluded that the histochemical characteristics of spontaneous or induced mouse hepatocellular neoplasms are variable and may be influenced by the inducing factors. 相似文献
83.
Rajasekharan P. Pillai Robert E. Lenkinski Ted T. Sakai J.Michael Geckle N.Rama Krishna Jerry D. Glickson 《Biochemical and biophysical research communications》1980,96(1):341-349
The assignment of the paramagnetically shifted resonances of the Fe(II)-bleomycin complex in D2O has been accomplished using the transfer of saturation method. A number of additional resonances arising from labile N protons which are shifted by the metal ion are observed in the 1H spectrum of the complex in H2O. The temperature dependence of the chemical shifts is consistent with the formation of an isolated 1:1 complex, but does not obey either the Curie Law or the Curie-Weiss Law. The magnitude of the shifts suggests that the valeric acid hydroxyl (or carbonyl) group, the α-amino group, the imidazole Nπ, the carbamoyl oxygen, the pyrimidine N1 and/or the secondary amino group may be coordinated to the iron(II). 相似文献
84.
85.
A new method of in situ hybridization 总被引:27,自引:0,他引:27
Jerry E. Manning N. Davis Hershey Thomas R. Broker Maria Pellegrini Herschel K. Mitchell Norman Davidson 《Chromosoma》1975,53(2):107-117
A new method for gene mapping at the chromosome level using in situ hybridization and scanning electron microscopy is described and has been applied to mapping the rRNA genes of Drosophila melanogaster. Biotin is covalently attached to Drosophila rRNA via a cytochrome c bridge at a ratio of one cytochrome-biotin per 130 nucleotides by a chemical procedure. Polymethacrylate spheres with a diameter of ca. 60 nm are prepared by emulsion polymerization and are covalently attached to the protein avidin at a ratio of 5–20 avidins per sphere. The biotin-labeled rRNA is hybridized to denatured DNA in a chromosome squash. Upon incubation with a sphere solution, some of the biotin sites become labeled with spheres because of the strong non-covalent interaction between biotin and avidin. The chromosome squash is examined in the scanning electron microscope (SEM). Polymer spheres, which are visible in the SEM, are observed to label the nucleolus, where the rRNA genes are located.Contribution number 5121 from the Department of Chemistry. 相似文献
86.
The relative rate of turnover of individual membrane proteins and glycoproteins in exponentially growing and contact-inhibited MK2 cells was investigated. Plasma membranes were isolated from cells that had been sequentially labelled with 14C and 3H isotopes of leucine and glucosamine. The membranes were then solubilized in sodium dodecylsulfate and their polypeptides separated by acrylamide gel electrophoresis. The 3H/14C ratios of the individual polypeptides reflected their relative rates of turnover. The proteins and glycoproteins of the exponentially growing cells exhibited markedly heterogeneous rates of turnover. In contrast, polypeptides in membranes of contact-inhibited cells exhibited a lesser degree of heterogeneity of turnover. In both exponential and contacted cell membranes a glycoprotein with a high apparent molecular weight exhibited the fastest rate of turnover. 相似文献
87.
Lack of Genic Similarity between Two Sibling Species of Drosophila as Revealed by Varied Techniques 下载免费PDF全文
Jerry A. Coyne 《Genetics》1976,84(3):593-607
Acrylamide gel electrophoresis was performed on the enzyme xanthine dehydrogenase in sixty isochromosomal lines of Drosophila persimilis from three geographic populations. Sequential electrophoretic analysis using varied gel concentrations and buffers revealed twenty-three alleles in this species where only five had been described previously. These new electrophoretic techniques also detected a profound increase in divergence of gene frequencies at this locus between D. persimilis and its sibling species D. pseudoobscura. The implications of these results for questions of speciation and the maintenance of genetic variability are discussed. 相似文献
88.
Bernard L. Powell Jerry W. Pickering Simon H. Wender Eddie C. Smith 《Phytochemistry》1975,14(8):1715-1717
Two anodic isoperoxidases (A1 and A2) from tobacco tissue culture W-38 and two cathodic isoperoxidases (C3 and C4) from tobacco suspension culture WR-132 have been separated and characterized. Molecular weights for each of the isoperoxidases have been determined by two different methods. Only C4 contained a carbohydrate component. The substrate specificity and the pH optima for the four enzymes with each of five substrates were determined. 相似文献
89.
Rick G. Kelsey Jerry W. Thomas Thomas J. Watson Fred Shafizadeh 《Biochemical Systematics and Ecology》1975,3(4):209-213
The sesquiterpene lactones and chromosome numbers for three chemical races of Artemisia tridentata ssp. vaseyana have been examined from four populations in western Montana. TLC analysis of the sesquiterpene lactones in the seeds and seed producing parents demonstrated that genetic exchange does occur between sympatric sesquiterpene lactone chemical races. However, other evidence suggests that introgression between these races is restricted to zones of sympatry. There appears to be no correlation between chromosome numbers and sesquiterpene lactone races. 相似文献
90.
William T. Evanochko Ted T. Sakai Thian C. Ng N.Rama Krishna Hyun Dju Kim Robert B. Zeidler Vithal K. Ghanta R.Wallace Brockman Lewis M. Schiffer Paul.G. Braunschweiger Jerry D. Glickson 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》1984,805(1):104-116
Perchloric acid extracts of radiation-induced fibrosarcoma (RIF-1) tumors grown in mice have been analyzed by multinuclear NMR spectroscopy and by various chromatographic methods. This analysis has permitted the unambiguous assignment of the 31P resonances observed in vivo to specific phosphorus-containing metabolites. The region of the in vivo spectra generally assigned to sugar phosphates has been found in RIF-1 tumors to contain primarily phosphorylethanolamine and phosphorylcholine rather than glycolytic intermediates. Phosphocreatine was observed in extracts of these tumor cells grown in culture as well as in the in vivo spectra, indicating that at least some of the phosphocreatine observed in vivo arises from the tumor itself and not from normal tissues. In the 31P-NMR spectra of the perchloric acid extract, resonances originating from purine and pyrimidine nucleoside di- and triphosphate were resolved. HPLC analyses of the nucleotide pool indicate that adenine derivatives were the most abundant components, but other nucleotides were present in significant amounts. The 1H and 13C resonance assignments of the majority of metabolites present in RIF-1 extracts have also been made. Of particular importance is the ability to observe lactate, the levels of which may provide a noninvasive measure of glycolysis in these cells in both the in vivo and in vitro states. In addition, the aminosulfonic acid, taurine, was found in high levels in the tumor extracts. 相似文献