Perl, M., Agricultural Research Organization, The Volcani Center, Bet-Dagan, Israel

An enzyme which splits reduced NAD has been partially purified from pea (Pisum sativum, Kelvedon Wonder) seeds. The activity requires orthophosphate and the products are ADP and probably NMN (dihydro NMN?). The enzyme splits the NADH2 at the pyrophosphate bond and incorporates the phosphate into the AMP residue. NAD, NADP or NADPH2 could not replace NADH2. The enzyme is unstable during storage, is activated by Mg2+ and by Mn2+, and inhibited by Ca2+. K+, Li+ and NH4 + have no effect. The possible role of this enzyme in the synthesis of ATP in seeds at the early stage of germination is discussed. © 1981.