Gymnemic acid interacts with mammalian glycerol-3-phosphate dehydrogenase.

In a previous study, we found interaction of gymnemic acid (GA) with glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a key enzyme in glycolysis. We now examined interaction of GA with glycolytic and related enzymes. We found that (1) GA induced a band smearing of glycerol-3-phosphate dehydrogenase (G3PDH) as well as that of GAPDH in SDS-PAGE, (2) GA diminished the G3PDH band detected by an antibody to phosphoserine, and (3) GA inhibited the G3PDH activity.