scholarly journals Bryodin, a ribosome-inactivating protein from the roots of Bryonia dioica L. (white bryony)

1986 ◽  
Vol 240 (3) ◽  
pp. 659-665 ◽  
Author(s):  
F Stirpe ◽  
L Barbieri ◽  
M G Battelli ◽  
A I Falasca ◽  
A Abbondanza ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Sugar Content ◽  
Neutral Sugar ◽  
Ribosome Inactivating Protein ◽  
Equimolar Ratio ◽  
Nicotiana Glutinosa ◽  
Whole Cells ◽  
Bryonia Dioica ◽  
Local Lesions ◽  
Reticulocyte Lysate

Bryodin is a strongly basic (pI greater than or equal to 9.5) glycoprotein (neutral sugar content 6.3%) with Mr 30,000, purified from the roots of Bryonia dioica (white bryony). This protein inhibits protein synthesis by a rabbit reticulocyte lysate with and ID50 (concentration causing 50% inhibition) of 0.12 nM (3.6 ng/ml) and has much less effect on protein synthesis by whole cells, with ID50 values ranging from 46 nM to 2.27 microM (1.4-67 micrograms/ml). Bryodin acts by inactivating ribosomes, with a less-than-equimolar ratio, which suggests a catalytic action. Bryodin decreases the number of local lesions induced by tobacco mosaic virus in the leaves of Nicotiana glutinosa. From all its properties, bryodin can be considered to be a ribosome-inactivating protein, similar to those already known [reviews: Barbieri & Stirpe (1982) Cancer Surveys 1, 489-520; Stirpe & Barbieri (1986) FEBS Lett. 195, 1-8].

scholarly journals Ribosome-inactivating proteins from the seeds of Saponaria officinalis L. (soapwort), of Agrostemma githago L. (corn cockle) and of Asparagus officinalis L. (asparagus), and from the latex of Hura crepitans L. (sandbox tree)

1983 ◽  
Vol 216 (3) ◽  
pp. 617-625 ◽  
Author(s):  
F Stirpe ◽  
A Gasperi-Campani ◽  
L Barbieri ◽  
A Falasca ◽  
A Abbondanza ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Sugar Content ◽  
Asparagus Officinalis ◽  
Inhibit Protein Synthesis ◽  
Nicotiana Glutinosa ◽  
Ribosome Inactivating Proteins ◽  
Local Lesions ◽  
Hura Crepitans ◽  
Reticulocyte Lysate ◽  
Saponaria Officinalis

Ribosome-inactivating proteins, similar to those already known [Barbieri & Stirpe (1982) Cancer Surveys 1, 489-520] were purified from the seeds of Saponaria officinalis (two proteins), of Agrostemma githago (three proteins), and of Asparagus officinalis (three proteins), and from the latex of Hura crepitans (one protein). The yield ranged from 8 to 400 mg/100 g of starting material. All proteins have an Mr of approx. 30000 and an alkaline isoelectric point. Their sugar content varies from 0 (proteins from S. officinalis) to 40% (protein from H. crepitans). The ribosome-inactivating proteins inhibit protein synthesis by rabbit reticulocyte lysate, the ID50 (concentration giving 50% inhibition) ranging from 1 ng/ml (a protein from S. officinalis) to 18 ng/ml (a protein from A. githago). Those which were tested (the proteins from S. officinalis and from A. githago) also inhibit polymerization of phenylalanine by isolated ribosomes, acting in an apparently catalytic manner. The protein from H. crepitans inhibited protein synthesis by HeLa cells, with an ID50 of 4 micrograms/ml, whereas the proteins from S. officinalis and from A. githago had an ID50 of more than 50-100 micrograms/ml. The ribosome-inactivating proteins from S. officinalis and from A. githago reduced the number of local lesions by tobacco-mosaic virus in the leaves of Nicotiana glutinosa.

scholarly journals Dianthins, ribosome-damaging proteins with anti-viral properties from Dianthus caryophyllus L. (carnation)

1981 ◽  
Vol 195 (2) ◽  
pp. 399-405 ◽  
Author(s):  
F Stirpe ◽  
D G Williams ◽  
L J Onyon ◽  
R F Legg ◽  
W A Stevens
Keyword(s):  
Protein Synthesis ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Dianthus Caryophyllus ◽  
Inhibit Protein Synthesis ◽  
Equimolar Ratio ◽  
Nicotiana Glutinosa ◽  
Intact Cells ◽  
Local Lesions ◽  
Rabbit Reticulocytes

1. Dianthin 30 and dianthin 32, two proteins isolated from the leaves of Diathus caryophyllus (carnation), were purified to homogeneity by chromatography on CM-cellulose. 2. The mol.wt. of dianthin 30 is 29 500 and that of dianthin 32 is 31 700. Both dianthins are glycoproteins containing mannose. 3. Dianthins inhibit protein synthesis in a lysate of rabbit reticulocytes, with an ID50 (concentration giving 50% inhibition) of 9.15 ng/ml (dianthin 30) and 3.6 ng/ml (dianthin 32). They act by damaging ribosomes in a less-than-equimolar ratio. Protein synthesis by intact cells is partially inhibited by dianthins at a concentration of 100 microgram/ml. 4. Dianthins mixed with tobacco-mosaic virus strongly decrease the number of local lesions on leaves of Nicotiana glutinosa.

scholarly journals Ribosome-inactivating proteins from plant cells in culture

1989 ◽  
Vol 257 (3) ◽  
pp. 801-807 ◽  
Author(s):  
L Barbieri ◽  
A Bolognesi ◽  
P Cenini ◽  
A I Falasca ◽  
A Minghetti ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Phytolacca Americana ◽  
Pokeweed Antiviral Protein ◽  
Antiviral Protein ◽  
Ribosome Inactivating Protein ◽  
Intact Cells ◽  
Ribosome Inactivating Proteins ◽  
Reticulocyte Lysate ◽  
Ic50 Concentration

1. Ribosome-inactivating proteins were found in high amounts in one line of cells of Phytolacca americana (pokeweed) cultured in vitro and, in less quantity, in lines of Saponaria officinalis (soapwort) and of Zea mays (corn) cells. 2. The main ribosome-inactivating protein from pokeweed cells was purified to homogeneity. It is a protein with Mr 29,000 and basic pI, similar to the ‘pokeweed antiviral protein’ (PAP), a ribosome-inactivating protein from pokeweed leaves. We propose to call the pokeweed antiviral protein isolated from pokeweed cells PAP-C. 3. PAP-C inactivates ribosomes in a less-than-equimolar ratio, thus inhibiting protein synthesis by a rabbit reticulocyte lysate with an IC50 (concentration causing 50% inhibition) of 0.067 nM (2 ng/ml), and modifies rRNA in a manner apparently identical to that of ricin and other ribosome-inactivating proteins. It inhibits protein synthesis by intact cells with an IC50 of 0.7-3.4 microM, and is toxic to mice with an LD50 of 0.95 mg/kg.

scholarly journals Purification and partial characterization of another form of the antiviral protein from the seeds of Phytolacca americana L. (pokeweed)

1982 ◽  
Vol 203 (1) ◽  
pp. 55-59 ◽  
Author(s):  
L Barbieri ◽  
G M Aron ◽  
J D Irvin ◽  
F Stirpe
Keyword(s):  
Protein Synthesis ◽  
High Yield ◽  
Phytolacca Americana ◽  
Pokeweed Antiviral Protein ◽  
Antiviral Protein ◽  
Whole Cells ◽  
Reticulocyte Lysate ◽  
Simplex Virus

1. The pokeweed antiviral protein, previously identified in two forms (PAP and PAP II) in the leaves of Phytolacca americana (pokeweed) [Obrig. Irvin & Hardesty (1973) Arch. Biochem. Biophys. 155, 278-289; Irvin, Kelly & Robertus (1980) Arch. Biochem. Biophys. 200, 418-425] is a protein that prevents replication of several viruses and inactivates ribosomes, thus inhibiting protein synthesis. 2. PAP is present in several forms in the seeds of pokeweed. One of them, which we propose to call ‘pokeweed antiviral protein from seeds’ (PAP-S) was purified in high yield (180 mg per 100 g of seeds) by chromatography on CM-cellulose, has mol.wt. 30 000, and is similar to, but not identical with. PAP and PAP II. 3. PAP-S inhibits protein synthesis in a rabbit reticulocyte lysate with an ID50 (concentration giving 50% inhibition) of 1.1 ng/ml (3.6 × 10(-11) M), but has much less effect on protein synthesis by whole cells, with an ID50 of 1 mg/ml (3.3 × 10(-5) M), and inhibits replication of herpes simplex virus type 1.

scholarly journals Resolution, purification and some properties of the multiple forms of cellobiose quinone dehydrogenase from the white-rot fungus Sporotrichum pulverulentum

1986 ◽  
Vol 236 (1) ◽  
pp. 221-226 ◽  
Author(s):  
F F Morpeth ◽  
G D Jones
Keyword(s):  
Superoxide Anion ◽  
Sugar Content ◽  
White Rot ◽  
Sedimentation Equilibrium ◽  
White Rot Fungus ◽  
Neutral Sugar ◽  
Apparent Difference ◽  
Multiple Forms ◽  
Sporotrichum Pulverulentum ◽  
Similar Kinetic

Four forms of cellobiose quinone dehydrogenase have been purified from the white-rot fungus Sporotrichum pulverulentum. The Mr of the enzyme has been estimated by sedimentation equilibrium to be 57,800 and by SDS/polyacrylamide-gel to be 60,000. These enzymes are clearly monomers. Cellobiose quinone dehydrogenases contain FAD and variable amounts of a green chromophore which we suggest is 6-hydroxy-FAD. The superoxide anion and H2O2 are the products of its reaction with oxygen. All of the isoenzymes from any one preparation display similar kinetic parameters. However, these vary between preparations. The only apparent difference between the four separable isoenzymes is their neutral-sugar content.

Development of Haemoglobin by De-embryonated Chick Blastoderms Cultured in vitro and the Effect of Abnormal RNA upon its Synthesis

Development ◽  
1961 ◽  
Vol 9 (1) ◽  
pp. 202-221
Author(s):  
B. R. A. O'Brien
Keyword(s):  
Protein Synthesis ◽  
Developmental Stages ◽  
Specific Protein ◽  
Cytoplasmic Protein ◽  
Whole Cells ◽  
Restricted Group ◽  
Dividing Cells ◽  
First Time ◽  
Structural Code

The embryo provides a sequence of developmental stages in which proteins both structural and enzymatic appear or become detectable for the first time in a restricted group of dividing cells. The cells or tissues can be maintained in vitro for a period that may precede and include the synthesis of a specific ‘cytoplasmic’ protein. In this way systems of protein synthesis within the cells of higher organisms can be studied during those stages in which current hypotheses suggest that some structural code is passed on from the DNA of the nucleus to the cytoplasm where the synthesis of the protein becomes maximal. Acellular preparations have contributed much to the elucidation of protein synthesis, but it is doubtful whether actual net synthesis has been obtained in systems less complex than the ‘protoplast’ developed by Spiegelman (1957). In order to study the synthesis of a specific protein it seems necessary at this stage to use whole cells.

Effect of amino acid deprivation on initiation of protein synthesis in rat hepatocytes

1989 ◽  
Vol 256 (1) ◽  
pp. C18-C27 ◽  
Author(s):  
W. V. Everson ◽  
K. E. Flaim ◽  
D. M. Susco ◽  
S. R. Kimball ◽  
L. S. Jefferson
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Rat Hepatocytes ◽  
Initiation Factor ◽  
Synthetic Activity ◽  
Perfused Liver ◽  
Amino Acid Deprivation ◽  
Isolated Rat Hepatocytes ◽  
Reticulocyte Lysate

Conditions were defined for maintaining optimal protein synthetic activity in suspensions of freshly isolated rat hepatocytes. Under these conditions, isolated hepatocytes exhibited rates of protein synthesis and levels of polysomal aggregation equivalent to those observed in vivo and in perfused liver. Deprivation of total amino acids or single, essential amino acids resulted in a rapid decrease in the rate of protein synthesis, which was readily reversed by readdition of the deficient amino acid(s). The decrease was accompanied by a disaggregation of polysomes and an inhibition of 43S initiation complex formation, which was indicative of a limitation in the rate of initiation of protein synthesis. Extracts prepared from perfused liver deprived of amino acids were inhibitory to initiation of protein synthesis in reticulocyte lysate. The inhibition in reticulocyte lysate was accompanied by an increase in phosphorylation of the alpha-subunit of eukaryotic initiation factor 2 (eIF-2), suggesting activation of an eIF-2 alpha kinase or inhibition of a phosphatase in amino acid-deprived hepatocytes. This suggestion was confirmed by prelabeling hepatocytes with 32Pi before amino acid deprivation. Incorporation of 32Pi into eIF-2 alpha was two- to threefold higher in lysine-deprived cells than in hepatocytes incubated in fully supplemented medium. Overall, the results indicated that an increase in eIF-2 alpha phosphorylation was responsible for the defect in initiation of protein synthesis caused by amino acid deprivation.

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