Partial purification and characterization of ADP-ribosyltransferase produced by Legionella pneumophila.

Abstract

A scheme for the partial purification of a Legionella pneumophila product possessing ADP-ribosyl-transferase and NAD-glycohydrolase activities is presented. The purification steps consisted of gel chromatography, ion-exchange, hydrophobic interaction chromatography, and chromatofocusing. The partially purified preparation modified eukaryotic components of molecular mass 20-25 kDa, which it is proposed are GTP-binding proteins. Addition of bivalent cations as well as ATP to the reaction buffer was necessary for ADP-ribosylation. NAD (50 microM) and nicotinamide (16 mM) greatly inhibited incorporation of ADP-ribose into acceptor proteins.