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91.
Fritz A. Henn Rick Venema David Anderson Ake Sellstrom 《Journal of neurochemistry》1980,34(6):1671-1677
Abstract: An isolated fraction of Purkinje perikarya was prepared. This fraction had [3 H]GABA receptor binding and [3 H]muscimol binding analogous to that reported for heterogeneous cerebellar membranes. The finding of two binding components with each ligand suggests that these components do not represent two binding sites, one presynaptic and the other postsynaptic, since both are clearly seen on purified Purkinje cell bodies. Subcellular fractionation indicates that synaptic endings and plasma membranes are enriched in GABA receptors compared with intracellular organelles. Purkinje cell bodies were also found to possess a high-affinity transport system for GABA, which was sensitive to inhibition by diaminobutyric acid (DABA) but not by β-alanine. They showed no evidence of homoexchange (the movement of label without net transport). This supports our suggestion that homoexchange is an artifact of synaptic particle formation. 相似文献
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Gerhard Toggenburger Max H?sermann Beat Mütsch Giulio Genoni Markus Kessler Fritz Weber Dietrich Hornig Brigitte ONeill Giorgio Semenza 《生物化学与生物物理学报:生物膜》1981,646(3):433-443
l-Ascorbate is taken up into brush border vesicles from kidney cortex of rat, rabbit and guinea pig by an efficient, Na+-dependent and potential-sensitive transport process. This uptake shows saturation () and is strongly stimulated by low concentrations of N3?. Erythorbate (d-isoascorbate) seems to be another, but poorer, substrate of the same transporter. 相似文献
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Summary Summary: Pre-purified preparations of myoinositol-1-phosphate synthase (E.C. 5.5.1.4) from rat testes can be purified to homogeneity by first crystallizing the enzyme according to JAKOBY and then recrystallizing it at a pH value close to the isoelectric point while slowly increasing the temperature from 0 to 15 °C. This method gives a much higher yield of homogeneous enzyme than the previously used purification by affinity chromatography. It was further found that the pure enzyme contains close to 2 mol NAD+ per mol enzyme; it does not contain any metal. At substrate saturation the enzyme binds close to 1 mol substrate per mol enzyme, as determined by using radioactively labelled substrate and binding it to the enzyme by reduction with NaBH4. The reaction catalyzed by the enzyme is irreversible.Dedicated tp PROFESSOR O. E. Polansky on the occasion of his 60th birthday. 相似文献
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Waldemar Lernhardt Jan Andersson Antonio Coutinho Fritz Melchers 《Experimental cell research》1978,111(2):309-316
Addition of 3 × 106 thymus cells from either syngeneic, allogeneic or xenogeneic animals increases the cloning efficiencies of murine thymomas (EL-4, WC-2), B-lymphomas (McPC 1748, 38C-13), Abelson-virus transformed cell lines (F and K), mastocytomas (P815), myelomas (AbPC22, X63-AG8, 5563, MOPC 104 E, RFC 5, W 3469) and hybrids of myelomas and normal B-lymphocytes (Sp-1), all adapted to tissue culture, to near 100%. Thymus cells also increase the efficiencies of growth initiation in primary in vitro cultures of myeloma tumor cells (S117) transplanted in vivo, and of cells fused between the azaguanine-resistant X63-AG8 myeloma cell line and normal, LPS-stimulated B-lymphocyte blasts. 相似文献
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The glandular kininogenase kallikrein is known to occur in many mammalian organs and glands but direct histochemical localization has been achieved in only a few cases. We have now been able to localize porcine kallikrein in the acinar cells of the pancreas and in the striated and collecting duct cells of the submandibular gland. Incubation of frozen and fixed sections with one of the crossreacting antibodies, anti-pancreatic, anti-submandibular or anti-urinary kallikrein IgG resulted in the same immunofluorescence pattern. There was evidence of a specific fluorescence neither in the acinar cells, nor in the interstitial tissue or blood cells of the submandibular gland nor in the islets of Langerhans, the interlobular ducts or blood vessels of the pancreas. From all data now available about glandular kallikreins, it seems that the kallikreins in these organs are very similar. 相似文献
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Lymphocytes from healthy donors and from patients with chronic lymphocytic leukemia (CLL) were stimulated to divide with sodium periodate. The time of maximal response of normal lymphocytes to sodium periodate (NaIO4) was earlier than that observed to phytohemagglutinin (PHA), but the magnitude was lower. In comparison, CLL lymphocytes responded to NaIO4 more extensively and earlier than to PHA. 相似文献