A pre-steady state and steady state kinetic analysis of the N-ribosyl hydrolase activity of hCD157.

•Nicotinamide riboside (NR) and nicotinic acid riboside (NAR) are hydrolyzed by hCD157.•The enzyme hydrolyzes NR with a kcat/KM of 17μM−1s−1. NR is the preferred substrate for hCD157.•The long half-life (7s) of the catalytic intermediate suggests that hydrolysis proceeds through a covalent intermediate.