Activity determination of 3-iodopyridineadenine dinucleotide and its phosphate as hydride acceptors in the presence of dehydrogenases using a coupled redox system.

A new procedure for the activity measurement of NAD(P)+-dependent dehydrogenases has been devised using an electron-transferring agent, phenazine methosulfate, and an electron acceptor, 3-(4,5-dimethylthiazolyl)-2,5-diphenyltetrazolium bromide. The reduction of the latter is determined by an increase in absorbance at 578 nm. 3-Iodopyridineadenine dinucleotide was found to be active as an hydride acceptor with horse liver alcohol dehydrogenase and lactate dehydrogenase but showed no activity with glyceraldehyde-3-phosphate dehydrogenase nor did its phosphate with 3-phosphogluconate dehydrogenase.