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IRIS è il sistema di gestione integrata dei dati della ricerca (persone, progetti, pubblicazioni, attività) adottato dall'Università degli Studi di Milano.

AIR nasce in UNIMI nel 2006 con lo scopo di raccogliere, documentare e conservare le informazioni sulla produzione scientifica dell'Università degli Studi di Milano e costituisce di fatto l'Anagrafe della ricerca dell'Ateneo.

An increasing number of studies correlated the expression of rhodanese-like proteins to the management of cellular redox omeostasis. In Azotobacter vinelandii, the absence of the rhodanese-like protein RhdA results in an impaired redox condition and in the activation of the OxyR-regulon mediated response. Moreover, the finding that in the RhdA-null mutant the glutathione pool was depleted and glutathione precursors were accumulated suggested an impairment in the regeneration pathway of reduced glutathione (GSH). In the presence of hydroxyl radical (OH*), GSH is oxidized to glutathione thiyl radical (GS*) which needs an enzymatic pathway to be recovered as glutathione disulfide (GSSG), a GSH-generable form. Proteins with a low-pKa cysteine residue (like in the case of RhdA) are good candidates to stabilize an adduct with GS* for enzymatic GSSG dependent recovery. In the present study, we found that RhdA was able to specifically bind both GSH and GS* in vitro with high affinity (Kd = μM range) and that RhdA-Cys230 residue was mandatory for the adduct formation. The RhdA/glutathione adduct was stable enough to be used as a substrate to produce GSSG (kcat = 628 s-1), despite MS analyses did not reveal the formation of a covalent bond. The RhdA scavenging activity of GS* was O2-dependent suggesting that O2 might be the final acceptor of the radical. The GS*-scavenging activity of RhdA supports the phenotype observed on the RhdA-null mutant defined in our previous studies, highlighting RhdA’s key role as ROS-level mediator by preserving glutathione from irreversible oxidations induced by OH*.

Involvement of the Azotobacter vinelandii rhodanese-like protein RhdA in the glutathione regeneration pathway / W. Remelli, N. Guerrieri, J. Klodmann, J. Papenbrock, H.P. Braun, S. Pagani, F. Forlani. ((Intervento presentato al 36. convegno FEBS Congress tenutosi a Torino nel 2011.

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