Incorporation of Uridine in Cleavage Stage Eggs of the Sea Urchin Paracentrotus Lividus

1971 ◽  
Vol 26 (8) ◽  
pp. 816-821 ◽  
Author(s):  
Larry E. Bockstahler
Keyword(s):  
Ion Exchange ◽  
Sea Urchin ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Paracentrotus Lividus ◽  
Cleavage Stage ◽  
Early Cleavage ◽  
Cell Stage ◽  
Cleavage Stages ◽  
Layer Chromatography

Incorporation of uridine in cleavage stage eggs of the sea urchin Paracentrotus lividus was investigated. It was shown by ion exchange and thin layer chromatography that most of the uridine taken up during the 16-cell stage was converted into UTP with some incorporation into UDP and UMP. Conversion of uridine to these phosphorylated nucleosides occurred throughout early cleavage stages. A very small amount of uridine taken up by cleavage stage eggs is incorporated into RNA heterogeneous in size. This RNA was examined by polyacrylamide gel electrophoresis.

Purification and properties of mercuric reductase from Yersinia enterocolitica 138A14

1993 ◽  
Vol 39 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Mohamed Blaghen ◽  
Dominique J. M. Vidon ◽  
Mohamed Said El Kebbaj
Keyword(s):  
Molecular Weight ◽  
Yersinia Enterocolitica ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Mercury Resistance ◽  
Thiol Compounds ◽  
Mercuric Reductase ◽  
Purification And Properties ◽  
Layer Chromatography

A mercuric ion-reducing flavoprotein was purified from Yersinia enterocolitica 138A14 using dye matrix affinity chromatography. The purified enzyme had a characteristic absorption spectrum similar to those of flavin compounds, and FAD was detected as a part of the purified enzyme by thin-layer chromatography. Freshly purified preparations of the enzyme showed a single band on SDS polyacrylamide gel electrophoresis with a molecular weight of 70 000. The isolated enzyme had a molecular weight of about 200 000 as determined by gel filtration and disc gel electrophoresis. These results suggest an apparently trimeric structure of the enzyme. Dithiothreitol treatment disrupted the trimer into a dimeric structure of 140 000. Along with ageing, as well as limited proteolytic digestion, the enzyme evolved to give a dimeric molecule of 105 000 composed of two identical subunits of 52 000. The combination of the purified enzyme with HgCl2, or unexpectedly with merthiolate, oxidised the NADPH, which was followed spectrophotometrically. The Km for HgCl2 was dependent on the concentration of exogenous thiol compounds. A comparison of physical properties as well as kinetic characteristics indicated that the enzyme from Y. enterocolitica 138A14 is similar to mercuric reductases isolated from other mercury-resistant bacteria.Key words: Yersinia enterocolitica, mercury resistance, mercuric reductase.

Origin and behaviour of pigment cells in sea urchin embryos

Zygote ◽  
1999 ◽  
Vol 8 (S1) ◽  
pp. S42-S43 ◽  
Author(s):  
Tetsuya Kominami
Keyword(s):  
Sea Urchin ◽  
Pigment Cell ◽  
Cell Lineage ◽  
Pigment Cells ◽  
Cleavage Stage ◽  
Fate Map ◽  
Blastula Stage ◽  
Cell Stage ◽  
Stage Embryo ◽  
Founder Cells

Sea urchin pluteus larvae contain dozens of pigment cells in their ectoderm. These pigment cells are the descendants of the veg2 blastomeres of the 60-cell stage embryo. According to the fate map made by Ruffins and Ettensohn, the prospective pigment cells occupy the central region of the vegetal plate. Most of these prospective pigment cells exclusively give rise to pigment cells. Therefore, specification of the pigment cell lineage should occur at some point between the 60-cell and mesenchyme blastula stage. However, the detailed process of the specification of the pigment lineage is unknown.When are pigment cells specified? Are cell interactions necessary for the specification? Do founder cells exist? To answer these questions, I treated embryos with Ca2+-free seawater during the cleavage stage and examined the number of pigment cells observed in pluteus larvae. Treatment at 5.5–8.5 h and especially 7.5–10.5 h postfertilisation markedly reduced the number of pigment cells. The decrease was statistically significant. On the other hand, the treatment at 3.5–6.5 h or 9.5–12.5 h never reduced the number of pigment cells. By examining the frequency of the appearance of embryos whose numbers of pigment cells were less than 20, it was also found that the numbers of pigment cells were frequently in multiples of 4. Embryos having 4, 8, 12, 16 and 20 pigment cells were more frequently observed. Statistics indicated that the frequency of appearance was not random. These results indicated that cell contacts are necessary for the specification of pigment cells and that the specification occurs from 7 to 10 h postfertilisation. The results also suggest that the founder cells, if they exist, divide twice before they differentiate into pigment cells.

Rapid separation of bovine caseins by mass ion exchange chromatography

1989 ◽  
Vol 56 (3) ◽  
pp. 391-397 ◽  
Author(s):  
K. F. Ng-Kwai-Hang ◽  
J. P. Pélissier
Keyword(s):  
Liquid Chromatography ◽  
Ion Exchange ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Polyacrylamide Gel ◽  
Rapid Separation ◽  
Rapid Isolation ◽  
Time Required

SummaryThe rapid isolation of major bovine caseins in gram quantities was investigated. Whole casein was precipitated from individual cow's milk by adjusting the pH to 4·6 and the precipitated casein was suspended in 4·5 M urea (pH 8·0) containing 0·02 M imidazole and 0·03 M β-mercaptoethanol, and bound on a QAE Zeta Prep 250 cartridge. Stepwise elution with the urea/imidazole β-mercaptoethanol buffer and varying amounts of NaCl gave five well resolved peaks, which were identified by polyacrylamide gel electrophoresis and fast protein liquid chromatography to be pure γ-casein, κ-casein. β-casein, β-casein and αs-casein, respectively. The ion exchange cartridge was regenerated by flushing with buffer containing 0·50 Μ-NaCl followed by equilibration with starting buffer before separation of next sample. The time required to run each sample including cartridge regeneration and equilibration was 4 hours.

scholarly journals Isolation of pure anhydrotetracycline oxygenase from Streptomyces aureofaciens

1988 ◽  
Vol 253 (1) ◽  
pp. 263-267 ◽  
Author(s):  
I Vancurová ◽  
J Volc ◽  
M Flieger ◽  
J Neuzil ◽  
J Novotná ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Isoelectric Focusing ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Size Exclusion ◽  
Streptomyces Aureofaciens ◽  
Hydrophobic Chromatography ◽  
Step Procedure

Anhydrotetracycline oxygenase was purified to homogeneity from Streptomyces aureofaciens, a producer of tetracycline. The enzyme was purified 60-fold in a 40% yield by a two-step procedure using a combination of hydrophobic chromatography and ion-exchange h.p.l.c. Purified anhydrotetracycline oxygenase was homogeneous according to SDS/polyacrylamide-gel electrophoresis, isoelectric focusing, ion-exchange h.p.l.c. on a Mono Q HR 5/5 column and size-exclusion h.p.l.c. on a TSK G 3000 SW column. The enzyme consists of two subunits of Mr 57,500, as determined by SDS/polyacrylamide-gel electrophoresis.

scholarly journals The membrane attack mechanism of complement: the three polypeptide chain structure of the eigth component (C8).

1976 ◽  
Vol 143 (5) ◽  
pp. 1131-1139 ◽  
Author(s):  
W P Klob ◽  
H J Müller-Eberhard
Keyword(s):  
Ion Exchange ◽  
Human Serum ◽  
Ammonium Sulfate ◽  
Gel Electrophoresis ◽  
Polypeptide Chain ◽  
Polyacrylamide Gel Electrophoresis ◽  
Chain Structure ◽  
Ammonium Sulfate Precipitation ◽  
Ion Exchange Column ◽  
Polypeptide Chains

The purification of human C8 in milligram quantities from outdated human serum was achieved by ammonium sulfate precipitation (37.5-50% saturation) and ion exchange column chromatography employing CM-32 cellulose and QAE-Sephadex. The yield of C8 activity ranged from 2-9%, and the average purification was 1,700-fold. Fully reduced C8 was shown by SDS polyacrylamide gel electrophoresis to have three polypeptide chains which were present in equimolor ratios: alpha, 77,000 daltons; beta, 63,000 daltons; and gamma, 13,700 daltons. C8 denaturation by SDS and urea in the absence of reducing agents revealed two noncovalently linked subunits: alpha-gamma, 99,000 daltons, and beta, 75,000 daltons.

DNS-Synthese in frühen Furchungsstadien von Seeigelembryonen / DNA-Synthesis in Early Cleavage Stages of Sea Urchin Embryos

1970 ◽  
Vol 25 (9) ◽  
pp. 1047-1052 ◽  
Author(s):  
G. Czihak ◽  
E. Pohl
Keyword(s):  
Dna Synthesis ◽  
Sea Urchin ◽  
Incubation Time ◽  
Transport Mechanism ◽  
Nuclear Dna ◽  
Incorporation Rate ◽  
Thymidine Uptake ◽  
Early Cleavage ◽  
Single Nucleus ◽  
Cleavage Stages

Incorporation rate of thymidine into nuclear DNA of cleaving sea urchin eggs is independent of the incubation time before fertilization. The incorporation rate into the single nucleus was found to be higher in later cleavage stages than immediately after fertilization. A constant value is reached after a certain time. Thymidine uptake is considered to be dependent on a transport mechanism starting with fertilization.

Uptake of valine and alanine by a neutral amino-acid carrier in sea urchin eggs: cyclic variations in the early cleavage stage

1985 ◽  
Vol 87 (3) ◽  
pp. 217-224 ◽  
Author(s):  
Denis Allemand ◽  
Guy De Renzis ◽  
Corrinne Maistre ◽  
Jean-Pierre Girard ◽  
Patrick Payan
Keyword(s):  
Amino Acid ◽  
Sea Urchin ◽  
Neutral Amino Acid ◽  
Cleavage Stage ◽  
Early Cleavage ◽  
Sea Urchin Eggs ◽  
Cyclic Variations ◽  
Amino Acid Carrier

scholarly journals Molecular forms of myeloperoxidase in human plasma

1986 ◽  
Vol 237 (2) ◽  
pp. 559-565 ◽  
Author(s):  
R L Olsen ◽  
T K Steigen ◽  
T Holm ◽  
C Little
Keyword(s):  
Ion Exchange ◽  
Human Plasma ◽  
Gel Electrophoresis ◽  
Large Subunit ◽  
Polyacrylamide Gel Electrophoresis ◽  
Immunoaffinity Chromatography ◽  
Molecular Forms ◽  
Active Components ◽  
Protein Blotting ◽  
Catalytically Active

A radioimmunoassay for myeloperoxidase was established with the use of affinity-purified anti-(human myeloperoxidase) immunoglobulins. By the use of ion-exchange followed by immunoaffinity chromatography a preparation of immunoreactive, catalytically active myeloperoxidase was obtained from fresh human plasma. In non-denaturing gel electrophoresis, the plasma preparation showed about four catalytically active components of mobility very similar to that of the granulocyte enzyme. SDS/polyacrylamide-gel electrophoresis combined with protein blotting showed that the two polypeptides of strongest antigenicity in the plasma preparation corresponded in Mr to the large and the small subunits of the granulocyte enzyme. In addition, the plasma preparation contained a higher-Mr immunoreactive polypeptide, possibly a precursor form of the enzyme, together with another of Mr similar to that of the large subunit of eosinophil peroxidase.

Memoirs: A Quantitative Study of the Changes in the Cytosome of Eggs of the Echinodermata During Early Cleavage

1938 ◽  
Vol s2-80 (318) ◽  
pp. 285-291
Author(s):  
D. PELLUET
Keyword(s):  
Quantitative Study ◽  
Sharp Increase ◽  
Marked Decrease ◽  
Preliminary Investigation ◽  
Gastrula Stage ◽  
Early Cleavage ◽  
Cell Stage ◽  
Asterias Forbesi ◽  
Cleavage Stages ◽  
Significant Change

An estimate of the changes in volume, fat, and mitochondria occurring in the early cleavage stages of Arbacia has been made. The volume fluctuates with each successive cleavage, but it is probable that there is no significant change until after the gastrula stage has been reached. The number of fat-granules decreases steadily from the unfertilized to the four-cell stage, with a slight increase in the blastula. The mitochondria show a slight decrease between the unfertilized and fertilized condition and a marked decrease at the four-cell stage, followed by a sharp increase in the blastula. A preliminary investigation of another Echinoderm, Asterias forbesi, suggests that it differs considerably from that of Arbacia. It is a pleasure to acknowledge the assistance of Dr. F. R. Hayes in several ways, and especially for checking many of the calculations.

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