Until recently, no enzymes were known with the sole function of catalyzing redox chemistry on phosphorus. Metcalf and coworkers identified two such proteins promoting the oxidation of hypophosphite to phosphite and phosphite to phosphate. The latter protein uses NAD+ as cofactor, making it essentially a phosphoryl transferase with water as nucleophile and hydride as leaving group (eq.). We are interested how this unusual transformation takes place. Furthermore, we are intrigued by the potential to use this enzyme as a commercial NADH regenerating system. Many enzymes perform very useful reactions for synthetic chemistry. Of these, the so called oxidoreductases are of special interest as they reduce prochiral carbonyl and imine containing compounds to chiral products with very high stereoselectivities. NAD(P)H is nature’s reducing agents in these enzymatic reactions. These compounds are very costly hampering use of the oxidoreductases in synthetic applications unless they can be regenerated in situ in which case catalytic amounts can be used.