Nature of primary product(s) of D-glucose 6-phosphate dehydrogenase reaction. 13C and 31P NMR study.

Glucose 6-phosphate dehydrogenase catalyzes the oxidation of glucose 6-phosphate, resulting in the formation of 6-phosphogluconolactone. As this compound is unstable, it has not been characterized directly. NMR provides a way to directly monitor all components of a reaction and study their structure. Here we report some results on the glucose 6-phosphate dehydrogenase reaction using 31P and 13C-NMR. Our results indicate that two different lactones, namely gamma (1-4) and delta (1-5) 6-phosphogluconolactones, are formed as products in this reaction. This is in contrast to an earlier suggestion that glucose 6-phosphate dehydrogenase produces only the delta-lactone. On the basis of these results, a new mechanisms for dehydrogenation of the sugar phosphate is proposed.