Pubblicazioni

Reductive activation of ricin and ricin A-chain immunotoxins by protein disulfide isomerase and thioredoxin reductase.  (2004)

Autori:
G. Bellisola; G. Fracasso; R. Ippoliti; G. Menestrina; A. Rosén; S. Soldà; S. Udali; R. Tomazzolli; G. Tridente; M. Colombatti
Titolo:
Reductive activation of ricin and ricin A-chain immunotoxins by protein disulfide isomerase and thioredoxin reductase.
Anno:
2004
Tipologia prodotto:
Articolo in Rivista
Tipologia ANVUR:
Articolo su rivista
Nazioni degli autori:
ITALIA
Lingua:
Inglese
Formato:
A Stampa
Referee:
Nome rivista:
Biochemical Pharmacology
ISSN Rivista:
0006-2952
N° Volume:
67
Intervallo pagine:
1721-1731
Codice PMID:
15081871
Parole chiave:
Ricin, Immunotoxin, Disulfide reduction, Protein disulfide isomerase, Thioredoxin, Thioredoxin reductase
Breve descrizione dei contenuti:
Intracellular activation of ricin and of the ricin A-chain (RTA) immunotoxins requires reduction of their intersubunit disulfide(s). This crucial event is likely to be catalyzed by disulfide oxidoreductases and precedes dislocation of the toxic subunit to the cytosol. We investigated the role of protein disulfide isomerase (EC 5.3.4.1, PDI), thioredoxin (Trx), and thioredoxin reductase (EC 1.8.1.9, TrxR) in the reduction of ricin and of a ricin A-chain immunotoxin by combining enzymatic assays, SDSPAGE separation and immunoblotting. We found that, whereas PDI, Trx, and TrxR used separately were unable to directly reduce ricin and the immunotoxin, PDI and Trx in the presence ofTrxR andNADPHcould reduce both ricin and immunotoxin invitro. PDI functioned only after pre-incubation withTrxR and the reductive activation of ricin was more efficient in the presence of glutathione. Similar results were obtained with microsomal membranes or crude cell extracts. Pre-incubation with the gold(I) compound auranofin, which irreversibly inactivates TrxR, resulted in a dose-dependent inhibition of ricin and immunotoxin reduction. Reductive activation of ricin and immunotoxin decreased or was abolished in microsomes depleted of TrxR and in cell extracts depleted of both PDI and Trx. Pre-incubation of U-937, Molt-3, Jurkat, and DU145 cells with auranofin significantly decreased ricin cytotoxicity with respect to mock-treated controls (P < 0:05). Conversely, auranofin failed to protect cells from the toxicity of pre-reduced ricin which does not require intracellular reduction of disulfide between the two ricin subunits.We conclude that TrxR, by activating disulfide reductase activity of PDI, can ultimately lead to reduction/activation of ricin and immunotoxin in the cell.
 
Reductive activation of ricin [pdf]
Id prodotto:
20209
Handle IRIS:
11562/303413
depositato il:
19 ottobre 2007
ultima modifica:
2 novembre 2016
Citazione bibliografica:
G. Bellisola; G. Fracasso; R. Ippoliti; G. Menestrina; A. Rosén; S. Soldà; S. Udali; R. Tomazzolli; G. Tridente; M. Colombatti, Reductive activation of ricin and ricin A-chain immunotoxins by protein disulfide isomerase and thioredoxin reductase. «Biochemical Pharmacology» , vol. 672004pp. 1721-1731

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