Has NAD(+) glycohydrolase activity and extremely low ADP-ribosyltransferase activity. L-arginyl-[protein] + NAD(+) = H(+) + N(omega)-(ADP-D-ribosyl)-L-arginyl-[protein] + nicotinamide H2O + NAD(+) = ADP-D-ribose + H(+) + nicotinamide Postthymic T-cells. Belongs to the Arg-specific ADP-ribosyltransferase family.