Biomedical subjects

D D Vandré

Publications and source records attributed to D D Vandré.

23 records · Page 2Linked to original sources

PubMed1986

Distribution of cytoskeletal proteins sharing a conserved phosphorylated epitope.

A group of antigens related by their reactivity with monoclonal antibodies MPM-1 and MPM-2 appear as cells enter mitosis. These antibodies bind to a phosphorylated epitope on certain proteins, and therefore the antigens are presumed to be a group of phosphoproteins. A subset of these proteins has been shown previously to be components of mitotic microtubule organizing centers in PtK1 cells. We present here evidence that the mitosis-specific appearance of these phosphoproteins is a phenomenon common to all eukaryotic cells. The MPM reactive phosphoproteins were localized to mitotic spindle poles regardless of whether the spindle formed in the cytoplasm after nuclear envelope breakdown (open mitosis) or within the nucleus (closed mitosis). This reactivity was not dependent upon the presence of centrioles at the spindle poles. Proteins that contained the phosphorylated epitope were not, however, restricted to mitotic cells. Cells of neuronal derivation and flagellated cells showed specific localization of MPM antibody to the microtubule network and basal bodies respectively. On immunoblots, the MPM antibody reacted with brain MAP-1 among a number of other phosphoproteins. The identification of microtubule-associated protein (MAP)-1 correlates with the localization of the antibody to microtubules of neuroblastoma cells. These results suggest, that different phosphoprotein molecules detected by the MPM antibody may be specific for different mitotic microtubule organizing centers, basal bodies, and other specialized cytoskeletal structures; and the presence of a related phosphorylated domain on these proteins may be important for their proper function and/or interaction with microtubules.

Animals↗

PubMed1982

Largomycin: preparation, properties, and structure.

Largomycin has been purified to homogeneity by chromatography on hydroxylapatite whereby carbohydrate and protease impurities were removed. Largomycin is an acidic protein (pI 4.13, molecular weight 29300) which forms a dimer in phosphate buffer. An N-terminal amino acid sequence analysis from the amino-terminal residue gave, for the first 32 residues, Asp-Ile-Leu-Ile-Ala-Gly-Ala-Thr-Gly-Asn-Val-Gly-Lys-Pro-Leu-Val-Glu-Gly-Leu-Leu - Ala-Ala-Gly-Lys-Pro-Val-Arg-Ala-Leu-Thr-Arg-Asn... The sequence from the carboxyl terminus was -Ala-Ala-Leu-Phe-OH with threonine, valine, and glutamic acid being released upon prolonged digestion. The same amino acid sequences were found for largomycin prepared from either the culture broth or the mycelium of Streptomyces pluricolorescens. The similarities extended to the other physical properties, the antimicrobial activity against Staphylococcus aureus and Sarcina lutea, and the antitumor activity against KB cells. Largomycin inhibits the biosynthesis of DNA and RNA. An iodinated derivative did not bind to KB cells. The antimicrobial activity was lost following ultraviolet irradiation, protection against which was not afforded by p-aminobenzoic acid.

Amino Acid Sequence↗

PubMed1982

Antitumor proteins of Streptomyces macromomyceticus: purification and characterization of auromomycin, macromomycin A, and macromomycin D.

Macromomycin A and the two related proteins auromomycin and macromomycin D were isolated from the culture filtrates of Streptomyces macromomyceticus by chromatography on columns of DEAE-cellulose, Amberlite XAD-7, and decylagarose. Antibodies prepared against macromomycin A showed antigenic identity by Ouchterlony double diffusion between the three purified proteins. This similarity was further demonstrated by their behavior on disc gel electrophoresis, the amino acid compositions, and comparative peptide mapping of the aminoethylated derivatives. They differed, however, in other chemical and biological properties. Auromomycin and macromomycin A, pI 5.4, have antibiotic activity, which is absent in macromomycin D, pI 5.2. This antibiotic activity was associated with chromophore groups that were extractable by methanol. High-pressure liquid chromatography of the methanol extracts gave difference profiles for each of the purified proteins. The differences in the three proteins extended to their ultraviolet-visible spectra, fluorescence and circular dichroism, and the changes of these properties with heating. The heat denaturation, with auromomycin and macromomycin melting at 70.5 degrees C and macromomycin D at 57.0 degrees C, was reversible. Changes were noted in the spectra both during and following heating at 80 degrees C; the antibacterial activity was lost in auromomycin and only partially reduced in macromomycin A. The properties of the three proteins support the general similarities in their polypeptide structures, modifications in the properties of which are endowed by the differences in the associated nonprotein chromophores.

Amino Acids↗

PubMed1980

Effects of cesalin on the ultrastructure and biological properties of cultured mammalian cells.

Cesalin rapidly inhibits the incorporation of uridine and thymidine into KB, MCF-7, HBL-100, and HTC cells but has no measurable effect on AlAb cells. Protein syntheiss is inhibited only after the effect on DNA and RNA is observed. After 12 to 48 hr, the cells in cultures containing cesalin increasingly lose adhesion to the flask surface and float in the medium. Both the inhibition of nucleotide incorporation and the inhibition of the cell growth, used as assays for cytotoxicity, show a varying sensitivity of these cell lines to cesalin, with AlAb cells being the most resistant and KB cells being the most sensitive. The ultrastructural changes induced by cesalin in KB cells demonstrate alteration in the nucleolus, increase in rough endoplasmic reticulum, extensive blebbing of the plasma membrane, and invagination of the nuclear membrane. The blebbing of the plasma membrane decreases after 24 hr with the appearance of a highly disorganized nuclear structure and numerous vacuoles containing insoluble fragments.

Cell Line↗

PubMed1979

Effects of macromomycin on the ultrastructure and biological properties of cultured mammalian cells.

Macromomycin is shown to inhibit the biosynthesis of RNA, DNA, and protein in cultured cells of KB, HBL-100, SW-613, MCF-7, and A1Ab. There was no substantial increase in cell numbers in cultures containing macromomycin (5 microgram/ml), but after 24 to 48 hr the cells were two to three times the diameter of control cells with concomitant increase in cell protein. The ultrastructural changes induced by macromomycin in KB cells demonstrate an increase in nuclear size without similar changes in the size of other cytoplasmic subcellular units. It was of interest to note the general proliferation of cellular organelles and the increased occurrence of annulate lamellae followed, after prolonged treatment, by the appearance of larger numbers of lipid droplets and lysosomes; vacuoles developed to a significant extent after the cells detached from the monolayer. A1Ab cells show ultrastructural changes similar to those of KB cells when treated with macromomycin.

Antibiotics, Antineoplastic↗