NADPH ACTIVATES A DECARBOXYLATION REACTION CATALYZED BY LAMB LIVER 6-PHOSPHOGLUCONATE DEHYDROGENASE

NADP-dependent lamb liver 6-phosphogluconate deydrogenase catalyses the oxidative decarboxylation of 2-deoxy-6-phospho-gluconate, an analogue of the natural substrate. The first products of the reaction are NADPH and 3-keto-2-deoxy-6-phospho-gluconate. The NADPH, released from the enzyme, binds to the coenzyme site of the same or the other subunit, activating the decarboxylation reaction in which has not a redox role, since it can be substituted by an analogue devoid of enzymatic redox power. These findings are compared to those obtained with other NADP-dependent decarboxylating dehydrogenases.