17 research outputs found
New monoclonal antibodies recognizing phosphorylated proteins in mitotic cells
No full textThree monoclonal antibodies which showed strong staining of mitotic cells by screening on the human cell line MCF-7 were isolated. The antigens detected by the DH7 and BF6 monoclonal antibodies were located predominantly in multiple extranucleolar patches in interphase cell nuclei. In mitotic cells a strong increase in the fluorescence intensity was accompanied by its redistribution into a fine speckled form. Metaphase chromosomes were unstained. Centrosomes, spindle poles or midbodies were not stained either before or after extraction of the cells with Triton X-100 under conditions which preserve microtubular structures. In immunoblots of interphase cell extracts only very few bands reacted with DH7 whereas in mitotic cell extracts approximately 30 bands were stained. BF6 also showed an increase in the intensity and number of bands detected in mitotic compared to interphase cell extracts, and the pattern was clearly different from that obtained with DH7. The BF6 antigen were extracted by 0.5% Triton X-100, whereas the DH7 antigen was not. Dephosphorylation of the antigens strongly reduced the binding of both antibodies as measured by immunoblotting and ELISA assays. The results suggested that BF6 and DH7 detect two different phosphorylated epitopes, each of which is shared by a different subset of proteins from mitotic cells. The third antibody, BD 12, bound to several polypeptides, including one of high molecular weight that appeared to correspond to the NuMA antigen. The epitope recognized by BD 12 was not sensitive to phosphatases
Elektronenmikroskopische Untersuchung der Feinstnikturen des Zytoplasma früher Embryonalstsdien von Ambystoma mexicaum
No full textAberrations in the Regulation of Cell Division and Differentiation as a Cause of Malignant Tumors
No full textIsolation and characterization of Thomsen-Friedenreich-specific antibodies from human serum
No full textThe Thomsen-Friedenreich (TF) disaccharide, galactose (Gal){beta}1- 3GalNAc{alpha}-, is a blood group-related oncofetal antigen with remarkable tumor specificity. Postpartum, carbohydrate structures on the cell walls of the gastrointestinal flora evoke natural antibodies of presumed TF specificity. These antibodies may provide an early barrier against TF-carrying tumor cells. Their possible role, however, has been difficult to assess, since so far only a multivalent immunosorbent, asialoglycophorin (aGP), has been employed for their preparation, and therefore their fine specificities have been only insufficiently defined. We have used a novel immunosorbent consisting of synthetic TF{alpha} disaccharides (Gal{beta}1-3GalNAc{alpha}-) coupled to polyacrylamide (PAA), which itself was covalently bound to cross-linked sepharose. For specificity analyses, aGP and a panel of PAA-conjugated mono- and oligosaccharides were employed. Binding to the PAA moiety was excluded. The affinity-purified anti-TF{alpha} antibodies were of the IgM (≥0.5 mg/100 ml of serum) and IgG (approximately 0.05 mg/100 ml of serum) classes. They did partially cross-react with TF{beta}, although we detected a second group of anti-TF{beta} antibodies (both IgM and IgG) which did not cross-react with TF{alpha}. The affinity-purified TF{alpha} antibodies showed only marginal cross-reactivity with the related antigens lactose, Gal, Tn or the Forssman antigen. Besides TF-specific antibodies, we found antibodies to the carbohydrate antigens Tn, Forssman and {beta}-D-Gal as well as to noncarbohydrate epitopes of glycophorin in human serum
Patterns of cytokeratins and lamins in rat liver and in rat liver cell lines as shown by immunoblotting using the monoclonal antibodies A 45-B/B3 and A 51-B/H4
No full textA novel series of anti-human glycophorin A (CD235a) antibodies defining five extra- and intracellular epitopes
No full textGlycophorin A (GPA, CD235a) is a major membrane glycoprotein and marker of cells of the erythroid lineage. It is also the target of Plasmodium falciparum and of influenza virus. We describe a novel series of 10 antibodies towards GPA, recognizing four extra- and intracellular peptide epitopes of this molecule (defined by epitope mapping) and one mixed peptide/carbohydrate epitope. All antibodies bind better to the desialylated than to the fully sialylated molecule, including those specific for the intracellular epitope. For some of the antibodies (representing all five epitopes) functional binding constants were determined by Surface Plasmon Resonance. The new panel complements the already known anti-glycophorin antibodies and offers several potential applications for, e.g., differential diagnosis of erythroleukemias, lineage analyses of erythroid cells, isolation of senescent erythrocytes, or a highly sensitive neuraminidase assay
Spaltung des α-L-Arabinofuranosids, β-<scp>D</scp> -Glucopyranosids und β-Cellobiosids von 4-Nitrophenol durch Enzyme verschiedener Pilze - ein Beitrag in Verbindung mit Versuchen zur Steigerung der Selektivität der Tumortherapie
No full textMetabolizing Activities of Postmitochondrial Liver Fractions (S-9) on Benzo[a]pyrene and Dimethylnitrosamine
No full textMonoklonale Antikoerper gegen das Thomsen-Friedenreich-Antigen, ihre Herstellung und ihre Verwendung zum Tumornachweis
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