Modifications of 60 S ribosomal subunits induced by the ricin A chain

Paleologue, Anne; Reboud, Jean‐Paul; Reboud, Anne-Marie

doi:10.1016/0014-5793(86)81052-3

Cited by 14 publications

(5 citation statements)

References 23 publications

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“…Biological activity assessed by the luciferase translation assay resembled IC 50 values (0.5 nM) calculated from detecting poly (U) translation when ricin is incubated with purified ribosomes (Paleologue et al 1986). The IC 50 values calculated from data in this study were also similar to studies by Langer et al (1996) who show that ricin has an IC 50 of 200 pM.…”

Section: Discussionmentioning

confidence: 70%

Microtiter‐Based Assay for Evaluating the Biological Activity of Ribosome‐Inactivating Proteins

Hale¹

2001

Pharmacology & Toxicology

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A microtiter assay was developed to quickly measure the biological activity of ricin or other ribosome‐inactivating proteins. Nuclease‐treated rabbit reticulocyte lysate containing luciferase mRNA was used to measure toxin activity via inhibition of protein synthesis. The relative biological activity was determined by comparing luminescence levels in treated samples versus those of untreated controls. The amount of luciferase translated, as measured by luminescence, was inversely proportional to the toxin concentration. Linear dose response curves were generated for both class I and class II toxins. When compared to normal serum controls, specific antibody against ricin effectively inhibited ricin activity. The assay is suitable for efficient in vitro screening of therapeutics, as well as for identifying samples containing ribosome‐ inactivating proteins.

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Section: Discussionmentioning

confidence: 70%

Microtiter‐Based Assay for Evaluating the Biological Activity of Ribosome‐Inactivating Proteins

Hale¹

2001

Pharmacology & Toxicology

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“…The inactivation of ribosomes by ricin is in fact associated with a destabilization of the 60 S ribosomal subunit demonstrable as an increased thermal release of the L5. 5 S rRNA complex (Paleologue et al, 1986), and the effect of ac-sarcin is associated with a weakening of the interaction between 28 S and 5.8 S rRNA (Walker et al, 1983).…”

Section: Discussionmentioning

confidence: 99%

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

Brigotti

Rambelli

Zamboni

et al. 1989

Biochemical Journal

102

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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.

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“…They are then translocated across the intracellular vesicular membranes [Beaumelle et al, 1993;van Deurs et al, 1987;Wales et al, 19921 and the released A chain acts as an N-glycosidase by hydrolysing a single bond between adenine and ribose at A4324 on 28s rRNA [Gluck et al, 1994;Greenfield, 1992;Endo et al, 1987;Endo and Tsurugi, 19881. This results in loss of protein synthesis activity, probably due to conformational changes in the ribosome [Paleologue et al, 1986;Wool et al, 19921. Several other events that take place during processing having an effect on ricin toxicity have also been studied.…”

Section: Introductionmentioning

confidence: 99%

Drugs that show protective effects from ricin toxicity in in vitro protein synthesis assays

1995

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We used an in-vitro, inhibition of protein synthesis assay (PSI) to test a wide variety of drugs for possible therapeutic use against ricin, a toxic glycoprotein that causes death in animals by inhibiting protein synthesis. Selection of test drugs was based on possible interference with ricin activity at different stages of the toxic process. Most of the drugs tested had no effect on ricin-induced PSI, were toxic when tested alone, or enhanced the toxicity of ricin. The only ones showing protection were galactose, lactose, and several derivatives of these sugars, Brefeldin A (BFA), 3'-azido-3'-deoxythymidine (AZT), and a purine derivative (BM33203). THe sugar derivatives provided 50% protection against a PSI ED99 of ricin (0.1 micrograms/ml). Concentrations of BFA greater than 0.5 micro M caused about 50% PSI by itself, but blocked any further inhibitory effects of ricin. AZT, at optimum concentrations, reached a maximum protection level of about 40% in the presence of an ED99 dose of ricin, while the nucleoside derivative, BM33203 and AZT appeared to have an additive effect, showing up to 80% protection from an ED99 dose of ricin. Drugs showing protection in the PSI cell assay showed no protection from ricin in a cell-free translation assay used to determine if they would block ricin at the protein synthesis site.

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Modifications of 60 S ribosomal subunits induced by the ricin A chain

Cited by 14 publications

References 23 publications

Microtiter‐Based Assay for Evaluating the Biological Activity of Ribosome‐Inactivating Proteins

Microtiter‐Based Assay for Evaluating the Biological Activity of Ribosome‐Inactivating Proteins

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

Drugs that show protective effects from ricin toxicity in in vitro protein synthesis assays

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