[40] ADP-ribosylarginine

Publisher Summary This chapter illustrates the chemical properties of glycosylguanidines and presents the methodology for their enzymatic synthesis. It describes the acceptor specificity of guanidine-dependent ADP-ribosyltransferases and the chemistry of glycosylguanidines. The chapter also reviews the literature regarding chemical synthesis and discusses procedures used for the enzymatic preparation of ADP-ribosylguanidine derivatives. The arginine-dependent ADP-ribosyltransferases catalyzes two reactions—namely, the slow hydrolysis of NAD + to ADP-ribose and nicotinamide and the ADP-ribosylation of guanidino compounds. The hydrolytic reaction is specific for water. The studies of acceptor specificity for a number of guanidine-dependent ADP-ribosyltransferases demonstrate that the in vitro reactions catalyzed by the transferases are relatively nonselective. The stereochemistry of the reaction has been determined by 1 H NMR for a number of these enzymes. Glycosylguanidines are quite stable to both acid and base and are resistant to attack by nucleophiles. Glycosylguanidines are reportedly prepared by the direct reaction of guanidine with reducing sugars although the microcrystalline products have an empirical formula indicating a 3:2 ratio of sugar to guanidine.