A NON-NUCLEOTIDE POLYMER FOUND IN THE DNA OF THE SAND DOLLAR, ECHINARACHNIUS PARMA: II. PRELIMINARY CHARACTERIZATION

1967 ◽  
Vol 45 (2) ◽  
pp. 281-287 ◽  
Author(s):  
Herbert S. Rosenkranz
Keyword(s):  
Buoyant Density ◽  
Sedimentation Coefficient ◽  
Negative Electrode ◽  
Cesium Chloride ◽  
Amino Sugar ◽  
Electrophoretic Analysis ◽  
Positive Test ◽  
Preliminary Characterization ◽  
Acid Hydrolysate

A preliminary characterization of the non-nucleotidic component present in the DNA of Echinarachnius parma was undertaken. This material has an extremely high sedimentation coefficient (907 S). It contains no deoxyribose and presumably no ribose. After acid hydrolysis it was strongly ninhydrin-positive and also gave positive tests for reducing sugars as well as a slightly positive test for amino sugars. Upon electrophoretic analysis of an acid hydrolysate, three ninhydrinpositive spots were detected. One of these migrated to the negative electrode with a mobility identical with that of galactosamine, the other migrated to the positive electrode, and the third was neutral at pH 6.3. The spot with a mobility identical with that of galactosamine also gave a positive test for amino sugar. The material was not attacked by α-amylase. However, digestion with a crude trypsin preparation resulted in loss of the banding property in gradients of cesium chloride. Exposure to purified trypsin did not completely digest it, but caused an increase in buoyant density.

scholarly journals Preliminary characterization of maturation-promoting factor from yeast Saccharomyces cerevisiae

1987 ◽  
Vol 88 (3) ◽  
pp. 273-281
Author(s):  
K. Tachibana ◽  
N. Yanagishima ◽  
T. Kishimoto
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Small Molecules ◽  
Sedimentation Coefficient ◽  
Restrictive Temperature ◽  
Dependent Manner ◽  
Yeast Saccharomyces Cerevisiae ◽  
Preliminary Characterization ◽  
M Phase ◽  
Maturation Promoting Factor

It has been known for some time that maturation-promoting factor (MPF) appears in a wide variety of eukaryotic cells at M phase and exerts equal M-phase-promoting activity in both meiotic cells and mitotic cells in a non-specific manner. MPF was extracted from cdc20 mutant cells of the yeast Saccharomyces cerevisiae synchronized at M phase by incubation at the restrictive temperature. When injected into immature oocytes of Xenopus laevis, yeast MPF caused meiosis reinitiation in a dose-dependent manner and even in the presence of cycloheximide. Yeast MPF exerted its activity in starfish oocytes as well. MPF activity was obtained only from cells in M phase and not from G1, S or G2 phase cells, indicating cyclical changes during the yeast mitotic cell cycle. Preliminary characterization of yeast MPF revealed that its activity was associated with a heat-labile protein having a sedimentation coefficient value of 6 S. In contrast to the current assumption that MPF is a Ca-sensitive phosphoprotein stabilized by phosphorylated small molecules, such as ATP and Na-beta-glycerophosphate, the present study revealed that yeast MPF was still active even after treatment with either Ca2+ or alkaline phosphatase. Furthermore, it was found that yeast MPF and these phosphorylated small molecules were complementary in inducing reinitiation of meiosis, since the meiosis-reinitiating activity was detected only when both were present simultaneously and almost undetectable when either of them was present alone.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Taxol-induced bundling of brain-derived microtubules.

1984 ◽  
Vol 99 (3) ◽  
pp. 940-946 ◽  
Author(s):  
P F Turner ◽  
R L Margolis
Keyword(s):  
Electron Microscopy ◽  
Rat Brain ◽  
Crude Extract ◽  
Electrophoretic Analysis ◽  
Preliminary Characterization ◽  
Crude Extracts ◽  
Two Samples ◽  
Microtubule Protein

Taxol has two obvious effects in cells. It stabilizes microtubules and it induces microtubule bundling. We have duplicated the microtubule-bundling effect of taxol in vitro and report preliminary characterization of this bundling using electron microscopy, sedimentation, and electrophoretic analyses. Taxol-bundled microtubules from rat brain crude extracts were seen as massive bundles by electron microscopy. Bundled microtubules sedimented through sucrose five times faster than control microtubules. Electrophoretic analysis of control and taxol-bundled microtubules pelleted through sucrose revealed no striking differences between the two samples except for a protein doublet of approximately 100,000 daltons. Taxol-induced microtubule bundling was not produced by using pure tubulin or recycled microtubule protein; this suggested that taxol-induced microtubule bundling was mediated by a factor present in rat brain crude extracts. Taxol cross-linked rat brain crude extract microtubules were entirely labile to ATP in the millimolar range. This ATP-dependent relaxation was also demonstrated in a more purified system, using taxol-bundled microtubules pelleted through sucrose and gently resuspended. Although the bundling factor did not recycle with microtubule protein, it was apparently retained on isolated taxol-stabilized microtubules. The bundling factor was salt extracted from taxol-stabilized microtubules and its retained activity was demonstrated in an add-back experiment with assembled phosphocellulose-purified tubulin.

Isolation and preliminary characterization of herpes Channel Catfish virus DNA

1980 ◽  
Vol 26 (2) ◽  
pp. 130-134 ◽  
Author(s):  
Jean Robin ◽  
Alice Rodrigue
Keyword(s):  
Channel Catfish ◽  
Gradient Centrifugation ◽  
Buoyant Density ◽  
Sedimentation Coefficient ◽  
Sodium Deoxycholate ◽  
Cesium Chloride ◽  
Equilibrium Density ◽  
Channel Catfish Virus ◽  
Phenol Extraction ◽  
Infected Cells

The DNA of Channel Catfish virus (CCV) was selectively extracted from infected cells with a 5% solution of sodium deoxycholate, deproteinized using sodium sarcosinate and pronase, and purified by phenol extraction followed by equilibrium density gradient centrifugation in a cesium chloride solution. CCV DNA displays a buoyant density of 1.715 g/cm3 in such a solution, as would be expected from a duplex DNA containing 56.1% of guanine plus cytosine. As estimated from both its sedimentation coefficient and length in the electron microscope, CCV DNA is a linear duplex molecule of approximately 85 × 106 daltons.

Partial Characterization of a Fibrinolytic Inhibitor Produced by Cultured Endothelial Cells Derived from Human Umbilical Vein

1982 ◽  
Vol 47 (02) ◽  
pp. 128-131 ◽  
Author(s):  
F Esnard ◽  
E Dupuy ◽  
A M Dosne ◽  
E Bodevin
Keyword(s):  
Endothelial Cells ◽  
Primary Culture ◽  
Ammonium Sulphate ◽  
Concanavalin A ◽  
Umbilical Vein ◽  
Human Umbilical Vein ◽  
Preliminary Characterization ◽  
Umbilical Vein Endothelial Cells ◽  
Ammonium Sulphate Saturation

SummaryA preliminary characterization of a fibrinolytic inhibitor released by human umbilical vein endothelial cells in primary culture is reported. This molecule of Mr comprised between 2 × 105 and 106 and of μ2 mobility precipitates at 43% ammonium sulphate saturation and is totally adsorbed on Concanavalin A Sepharose 4 B. A possible relationship with a macroglobulins is discussed.

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