scholarly journals Purification and properties of two lectins from the latex of the euphorbiaceous plants Hura crepitans L. (sand-box tree) and Euphorbia characias L. (Mediterranean spurge)

1983 ◽  
Vol 215 (3) ◽  
pp. 433-439 ◽  
Author(s):  
L Barbieri ◽  
A Falasca ◽  
C Franceschi ◽  
F Licastro ◽  
C A Rossi ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
B Lymphocytes ◽  
Human Blood ◽  
Plant Family ◽  
Sand Box ◽  
Purification And Properties ◽  
Euphorbia Characias ◽  
Hura Crepitans ◽  
Haemagglutinating Activity ◽  
Reticulocyte Lysate

1. From the latex of two members of the plant family Euphorbiaceae, Hura crepitans L. (sand-box tree) and Euphorbia characias L. (Mediterranean spurge), two lectins were purified by affinity chromatography on acid-treated Sepharose 6B followed by elution with D-galactose. 2. The lectin from E. characias is a single molecular species with Mr 80 000, made up of two identical subunits with Mr 40 000, and is a glycoprotein containing 11% carbohydrate. 3. The lectin from H. creptians appears as a mixture of three isolectins with Mr 140 000, consisting of four different subunits with Mr values 37 500, 35 500, 31 000, and 29 000. 4. Both lectins have haemagglutinating activity, with no specificity for human blood groups. The haemagglutinating activity is inhibited by D-galactose and by galactose-containing oligosaccharides. 5. The lectin from H. crepitans is mitogenic to human T-, but not to B-, lymphocytes. The latex of E. characias is mitogenic to T- and, to a lesser extent, to B-, lymphocytes, but the purified E. characias lectin has no mitogenic activity. 6. The lectin from H. crepitans, but not that from E. characias, inhibits protein synthesis by a rabbit reticulocyte lysate.

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 STUDIES ON THE MECHANISM OF ENDOGENOUS PYROGEN PRODUCTION

1974 ◽  
Vol 140 (4) ◽  
pp. 954-964 ◽  
Author(s):  
Phyllis Bodel
Keyword(s):  
Protein Synthesis ◽  
Dose Response ◽  
Human Blood ◽  
Temperature Elevation ◽  
Blood Monocytes ◽  
Endogenous Pyrogen ◽  
Inhibitor Of Protein Synthesis ◽  
Relationship Of ◽  
Pyrogenic Activity

The characteristics of pyrogen production and release by human blood monocytes were investigated. A dose-response assay of monocyte pyrogen in rabbits indicated a linear relationship of temperature elevation to dose of pyrogen at lower doses. Monocytes did not contain pyrogen when first obtained, nor did they release it spontaneously even after 5 days of incubation in vitro. Pyrogen production was apparent 4 h after stimulation by endotoxin or phagocytosis, and continued for 24 h or more. Puromycin, an inhibitor of protein synthesis, prevented both initiation and continuation of pyrogen production and release. Pyrogen-containing supernates retained most pyrogenic activity during overnight incubation even in the presence of activated cells. Lymphocytes appeared to play no role in either initiation or continuation of pyrogen production in these studies.

Biosensing estrogenic endocrine disruptors in human blood and urine: A RAPID cell-free protein synthesis approach

2018 ◽  
Vol 345 ◽  
pp. 19-25 ◽  
Author(s):  
Amin S.M. Salehi ◽  
Seung Ook Yang ◽  
Conner C. Earl ◽  
Miriam J. Shakalli Tang ◽  
J. Porter Hunt ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Endocrine Disruptors ◽  
Human Blood ◽  
Free Protein ◽  
Human Blood And Urine ◽  
Synthesis Approach ◽  
Cell Free Protein Synthesis

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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