In enzymology, a NAD+-protein-arginine ADP-ribosyltransferase is an enzyme that catalyzes the chemical reaction using nicotinamide adenine dinucleotide NAD+ + protein L-arginine ⇌ {\displaystyle \rightleftharpoons } nicotinamide + Nomega--protein-L-arginine NADP+ + protein L-arginine ⇌ {\displaystyle \rightleftharpoons } nicotinamide + Nomega-[-D-ribosyl]-protein-L-arginineas well as the corresponding reaction using nicotinamide adenine dinucleotide phosphate NADP+ + protein L-arginine ⇌ {\displaystyle \rightleftharpoons } nicotinamide + Nomega--protein-L-arginine NADP+ + protein L-arginine ⇌ {\displaystyle \rightleftharpoons } nicotinamide + Nomega-[-D-ribosyl]-protein-L-arginineThus, the two substrates of this enzyme are NAD+ and protein L-arginine, whereas its two products are nicotinamide and Nomega--protein-L-arginine. Wikipedia