FIG. 3.

Pyruvate- and 2-oxoglutarate-dependent reduction of NADP by H. pylori cell extract. The pyruvate (A)- and 2-oxoglutarate (B)- and CoA-dependent reduction of NADP by H. pylori cell extract, under anaerobic conditions, is shown. The assays were carried out in a 2-ml volume, and the assay mixtures contained 5 mM 2-oxoglutarate or pyruvate, 0.1 mM CoA, 100 μl of H. pylori cell extract, and 1 mM NADP. The point of 2-oxoacid addition is indicated. The effect of pyruvate or 2-oxoglutarate addition on NADP reduction is indicated by the dashed line. The rate of NADP reduction under aerobic conditions is indicated by the solid line, and the rate of NAD reduction, added in place of NADP, is indicated by the dashed and dotted line. Reduction of NADP was observed in the presence of both pyruvate and 2-oxoglutarate and was dependent on anaerobic conditions. Furthermore, NADP could not be replaced by NAD.