scholarly journals Studies on the proteins from the seeds of Croton tiglium and of Jatropha curcas. Toxic properties and inhibition of protein synthesis in vitro

1976 ◽  
Vol 156 (1) ◽  
pp. 1-6 ◽  
Author(s):  
F Stirpe ◽  
A Pession-Brizzi ◽  
E Lorenzoni ◽  
P Strocchi ◽  
L Montanaro ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Jatropha Curcas ◽  
Crude Protein ◽  
Croton Tiglium ◽  
Ehrlich Ascites ◽  
Maximum Inhibition ◽  
Ehrlich Ascites Cells ◽  
Inhibition Of Protein Synthesis ◽  
Reticulocyte Lysate

1. Proteins extracted from the seeds of the Euphorbiaceae croton tiglium and Jatropha curcas were separated into three major peaks (I, II, and III) by Sephadex chromatography. 2. The crude protein from both seeds and peaks I and II from Croton and peak I from Jatropha were toxic to mice, to different extents. 3. The crude protein and peak I and peak II from both seeds, inhibited protein synthesis by a reticulocyte lysate; maximum inhibition was exerted by peak II from both seeds. None of these preparations affected protein synthesis in vitro by Ehrlich ascites cells.

scholarly journals Modeccin, the toxin of Adenia digitata. Purification, toxicity and inhibition of protein synthesis in vitro

1978 ◽  
Vol 174 (2) ◽  
pp. 491-496 ◽  
Author(s):  
A Gasperi-Campani ◽  
L Barbieri ◽  
E Lorenzoni ◽  
L Montanaro ◽  
S Sperti ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Affinity Chromatography ◽  
Ehrlich Ascites ◽  
Ehrlich Ascites Cells ◽  
Inhibition Of Protein Synthesis ◽  
Sepharose 4B ◽  
Rabbit Reticulocytes ◽  
In Cells

1. Modeccin, the toxin of Adenia digitata (Modecca digitata), was purified from the roots of this plant by affinity chromatography on Sepharose 4B. 2. This toxin is a protein with mol.wt. 57000, which on treatment with 2-mercaptoethanol can be dissociated into two subunits of mol.wts. 25000 and 32000. 3. Modeccin inhibits protein synthesis in vitro in a lysate of rabbit reticulocytes and in Ehrlich ascites cells; the effect on cells is decreased in the presence of lactose. 4. Dissociation of modeccin into subunits decreases the toxicity to animals and the inhibition of protein synthesis in cells, but enhances the inhibition of protein synthesis in the lysate system.

scholarly journals The Relation between Protein Synthesis and Lipide Accumulation in L Strain Cells and Ehrlich Ascites Cells

1959 ◽  
Vol 5 (3) ◽  
pp. 421-431 ◽  
Author(s):  
Donald W. King ◽  
Edward L. Socolow ◽  
Klaus G. Bensch
Keyword(s):  
Tissue Culture ◽  
Protein Synthesis ◽  
Cell Division ◽  
Growth Period ◽  
Cholesterol Content ◽  
Cell Ratio ◽  
L Cells ◽  
Ehrlich Ascites ◽  
Ehrlich Ascites Cells

It has long been known that fat accumulates in old injured cells both in tissue culture and in many mammalian disease states. The use of L cells grown in suspension tissue culture permitted the opportunity to study conditions in which lipide accumulation could be retarded or accelerated. These cultures exhibit a three-phase growth curve which is similar to that previously found with bacteria and consists of a lag period, logarithmic growth period, and stationary period. Daily aliquots were removed from cultures going through these phases and protein and cholesterol content correlated with cell division. It was found that L cells gradually accumulated lipide in the cell concurrent with retardation of cell division and protein synthesis. Conversely old lipide-laden cells, placed in fresh media and encouraged to active division with net protein synthesis progressed from a high to a low lipide/cell ratio over a period of 2 to 4 days. An amino acid analogue p-fluorophenylalanine and a mitotic inhibitor, colchicine, also markedly increased the lipide/cell ratio. Similar results were found in in vitro experiments with Ehrlich ascites cells.

EFFECT OF X-IRRADIATION ON DNA SYNTHESIS IN EHRLICH ASCITES CARCINOMA CELLS

1965 ◽  
Vol 43 (7) ◽  
pp. 859-864 ◽  
Author(s):  
Shan-Ching Sung
Keyword(s):  
Protein Synthesis ◽  
Dna Synthesis ◽  
Rna Synthesis ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Total Rna ◽  
Ehrlich Ascites ◽  
Ehrlich Ascites Cells ◽  
X Irradiation

The rate of DNA synthesis in Ehrlich ascites cells measured immediately after X-irradiation of 500 r for 6 minutes in vitro showed about 15% reduction. However, if X-irradiation was followed by preincubation of the cells, the subsequent synthesis of DNA in the X-irradiated cells was markedly inhibited. Under the same condition, the uptake of thymidine-2-C14, uridine-2-C14, adenine-8-C14, and glycine-1-C14, and protein synthesis in the X-irradiated cells were found to be almost the same as those in the non-irradiated control. RNA synthesis measured as total RNA was only slightly inhibited.

scholarly journals Generation of a mutant form of protein synthesis initiation factor eIF-2 lacking the site of phosphorylation by eIF-2 kinases.

1988 ◽  
Vol 8 (2) ◽  
pp. 993-995 ◽  
Author(s):  
V K Pathak ◽  
D Schindler ◽  
J W Hershey
Keyword(s):  
Protein Synthesis ◽  
Mammalian Cells ◽  
Covalent Modification ◽  
Site Directed Mutagenesis ◽  
Initiation Factor ◽  
Alpha Subunit ◽  
Mutant Form ◽  
Two Dimensional Gel Electrophoresis ◽  
Reticulocyte Lysate

The phosphorylation of the alpha-subunit of initiation factor eIF-2 leads to an inhibition of protein synthesis in mammalian cells. We have performed site-directed mutagenesis on a cDNA encoding the alpha-subunit of human eIF-2 and have replaced the candidate sites of phosphorylation, Ser-48 and Ser-51, with alanines. The cDNAs were expressed in vitro by SP6 polymerase transcription and rabbit reticulocyte lysate translation, and the radiolabeled protein products were analyzed by high-resolution two-dimensional gel electrophoresis. The wild-type and Ser-48 mutant proteins became extensively phosphorylated by eIF-2 kinases present in the reticulocyte lysate, and when additional heme-controlled repressor or double-stranded RNA-activated kinase was present, phosphorylation of the proteins was enhanced. The Ser-51 mutant showed little covalent modification by the endogenous enzymes and showed no increase in the acidic variant with additional eIF-2 kinases, thereby suggesting that Ser-51 is the site of phosphorylation leading to repression of protein synthesis.

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