Mariangela Del Vecchio
Italy
Research Article
Opposite Regulatory Effects of Iron Ions on the In Vitro Catalytic Activities of
Nare, the Toxin-like ADP-Ribosyltransferase from Neisseria meningitides
Author(s): Mariangela Del Vecchio and Enrico BalducciMariangela Del Vecchio and Enrico Balducci
NarE, the mono ADP-ribosyltransferase identified in Neisseria meningitidis, catalyzes three enzymatic reactions. NarE transfers a single ADP-ribose unit to guanidine compounds, hydrolyses NAD in nicotinamide and free ADP-ribose, and ADP-ribosylates itself. We have previously shown that NarE contains an iron-sulfur cluster by biophysical and biochemical analyses. The presence of a structured and stable iron-sulfur cluster is essential for ADP-ribosyltransferase but not for NAD-glycohydrolase activity. We report here that ferric, but not ferrous, ions stimulated the ADPribosyltransferase activity. On the contrary ferrous, but not ferric, ions activated NAD-glycohydrolase activity. These iron effects were reversed when enzymatic reactions were run in the presence of the iron-chelator O-phenantroline. In the presence of either ferric or ferrous ions there was an increase of the Vmax both .. View More»
DOI:
10.4172/2161-1009.1000214