Flammulin: A novel ribosome-inactivating protein from fruiting bodies of the winter mushroom Flammulina velutipes

2000 ◽  
Vol 78 (6) ◽  
pp. 699-702 ◽  
Author(s):  
H X Wang ◽  
T B Ng
Keyword(s):  
Deae Cellulose ◽  
Flammulina Velutipes ◽  
Fruiting Bodies ◽  
Terminal Sequence ◽  
Ribosome Inactivating Protein ◽  
Ribosome Inactivating Proteins ◽  
Rabbit Reticulocyte Lysate System ◽  
Free Translation ◽  
Reticulocyte Lysate ◽  
Low Ionic Strength

A protein with a molecular weight of 40 kDa, capable of inhibiting cell-free translation in a rabbit reticulocyte lysate system with an IC50 of 0.25 nM, was isolated from fruiting bodies of the mushroom Flammulina velutipes. The protein, designated flammulin, was devoid of ribonuclease activity. Flammulin was unadsorbed on DEAE-cellulose at neutral pH and low ionic strength and adsorbed on CM-Sepharose and Affi-gel blue gel under similar conditions. Its N-terminal sequence demonstrates sites of similarity to those of plant ribosome-inactivating proteins (RIPs).Key words: mushroom, ribosome-inactivating protein, fruiting body.

scholarly journals Effect of α-sarcin and ribosome-inactivating proteins on the interaction of elongation factors with ribosomes

1989 ◽  
Vol 257 (3) ◽  
pp. 723-727 ◽  
Author(s):  
M Brigotti ◽  
F Rambelli ◽  
M Zamboni ◽  
L Montanaro ◽  
S Sperti
Keyword(s):  
Higher Plants ◽  
Ricinus Communis ◽  
Ribosomal Subunit ◽  
Elongation Factor ◽  
Artemia Salina ◽  
Elongation Factors ◽  
Ribosome Inactivating Proteins ◽  
Rabbit Reticulocyte Lysate System ◽  
Reticulocyte Lysate ◽  
Comparable Activity

alpha-Sarcin from Aspergillus giganteus and the ribosome-inactivating proteins (RIPs) from higher plants inactivate the 60 S ribosomal subunit. The former is an RNAase, whereas RIPs are N-glycosidases. The site of cleavage of RNA and that of N-glycosidic depurinization are at one nucleotide distance in 28 S rRNA [Endo & Tsurugi (1987) J. Biol. Chem. 262, 8128-8130]. The effect of alpha-sarcin and that of RIPs on the interaction of elongation factors with Artemia salina (brine shrimp) ribosomes have been investigated. alpha-Sarcin inhibits both the EF1 (elongation factor 1)-dependent binding of aminoacyl-tRNA and the GTP-dependent binding of EF2 (elongation factor 2) to ribosomes, whereas two of the RIPs tested, ricin from Ricinus communis (castor bean) and volkensin from Adenia volkensii (kilyambiti), inhibit only the latter reaction. EF2 protects ribosomes from inactivation by both alpha-sarcin and ricin. The EF1-binding site is affected only by alpha-sarcin. The sensitivity of this site to alpha-sarcin is increased by pretreatment of ribosomes with ricin. A. salina ribosomes were highly resistant to the third RIP tested, namely gelonin from Gelonium multiflorum. All four proteins tested have, however, a comparable activity on the rabbit reticulocyte-lysate system.

A novel ribonuclease from the veiled lady mushroom Dictyophora indusiata

2003 ◽  
Vol 81 (6) ◽  
pp. 373-377 ◽  
Author(s):  
Hexing Wang ◽  
Tzi Bun Ng
Keyword(s):  
Molecular Mass ◽  
Deae Cellulose ◽  
Transfer Rna ◽  
Rnase Activity ◽  
Fruiting Bodies ◽  
Terminal Sequence ◽  
Temperature Optimum ◽  
Ph Optimum

A ribonuclease (RNase), exhibiting a molecular mass of 28 kDa and specificity toward polyU and polyA and possessing an N-terminal sequence dissimilar to previously reported mushroom RNases, was isolated from dried fruiting bodies of veiled lady mushroom (Dictyophora indusiata). It demonstrated an RNase activity of 564 U/mg toward yeast transfer RNA. The RNase was adsorbed on DEAE-cellulose, CM-Sepharose, and Q-Sepharose. It demonstrated a pH optimum of 4–4.5 and a temperature optimum of 60 °C. There was a loss of RNase activity at temperatures above 60 °C.Key words: ribonuclease, Dictyophora indusiata, mushroom, purification.

scholarly journals Production of Active Nonglycosylated Recombinant B-Chain of Type-2 Ribosome-Inactivating Protein fromViscum articulatumand Its Biological Effects on Peripheral Blood Mononuclear Cells

2011 ◽  
Vol 2011 ◽  
pp. 1-9
Author(s):  
Tzu-Li Lu ◽  
Jing-Yuan Chuang ◽  
Jai-Sing Yang ◽  
Shau-Ting Chiu ◽  
Nai-Wan Hsiao ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Biological Effects ◽  
Ribosome Inactivating Protein ◽  
Peripheral Blood Mononuclear ◽  
Ribosome Inactivating Proteins ◽  
Preferential Binding ◽  
A Chain ◽  
Low Ionic Strength

Type-2 ribosome-inactivating proteins, composed of a toxic A-chain and lectin-like B-chain, display various biological functions, including cytotoxicity and immunomodulation. We here cloned the lectin-like B-chain encoding fragment of a newly identified type-2 RIP gene,articulatingene, fromViscum articulatum, into a bacterial expression vector to obtain nonglycosylated recombinant protein expressed in inclusion bodies. After purification and protein refolding, soluble refolded recombinant articulatin B-chain (rATB) showed lectin activity specific toward galactoside moiety and was stably maintained while stored in low ionic strength solution. Despite lacking glycosylation, rATB actively bound leukocytes with preferential binding to monocytes andin vitrostimulated PBMCs to release cytokines without obvious cytotoxicity. These results implicated such a B-chain fragment as a potential immunomodulator.

A novel ribonuclease from fresh fruiting bodies of the portabella mushroom Agaricus bisporus

2006 ◽  
Vol 84 (2) ◽  
pp. 178-183 ◽  
Author(s):  
H X Wang ◽  
T B Ng
Keyword(s):  
Carboxymethyl Cellulose ◽  
Agaricus Bisporus ◽  
Deae Cellulose ◽  
Fruiting Bodies ◽  
Terminal Sequence ◽  
Temperature Optimum ◽  
Ph Optimum

A 14 kDa ribonuclease with a novel N-terminal sequence was isolated from fresh fruiting bodies of the portabella mushroom. It was adsorbed on DEAE-cellulose and carboxymethyl-cellulose, and demonstrated the highest ribonucleolytic potency toward poly (A), 60% as much activity toward poly (C), 40% as much activity toward poly (U), and the least activity (7% as much) toward poly (G). It exhibited a pH optimum at pH 4.5 and a temperature optimum at 60 °C. Its activity at 100 °C was higher than that at 20 °C.Key words: ribonuclease, portabella mushroom, isolation.

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 A novel procedure for the rapid purification of plastocyanin from pea (Pisum sativum) leaves

1981 ◽  
Vol 193 (1) ◽  
pp. 375-378 ◽  
Author(s):  
A R Ashton ◽  
L E Anderson
Keyword(s):  
Ionic Strength ◽  
Pisum Sativum ◽  
Deae Cellulose ◽  
High Concentrations ◽  
Rapid Purification ◽  
Low Ionic Strength

Plastocyanin is soluble at high concentrations (greater than 3 M) of (NH4)2SO4 but under these conditions will adsorb tightly to unsubstituted Sepharose beads. This observation was utilized to purify plastocyanin from pea (Pisum sativum) in two chromatographic steps. Sepharose-bound plastocyanin was eluted with low-ionic-strength buffer and subsequently purified to homogeneity by DEAE-cellulose chromatography.

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