Abstract: The glycolytic enzyme, pyruvate kinase, exhibits moderate affinity [3H]isatin binding (KD ~10 µM), which is inhibited by ATP (IC50 25 µM) and deprenyl (IC50 5 µM). Interaction of pyruvate kinase with isatin and its inhibition by ATP and deprenyl has also been confirmed using an independent biosensor technique and immobilized isatin analogue, aminoisatin. This effect has some specificity because the enzyme, creatine phosphokinase, does not exhibit specific isatin-binding. It is suggested that interaction of pyruvate kinase with isatin may reflect some non-glycolytic functions of this enzyme.
Reference: Buneeva O.A., Gnedenko O.V., Medvedeva M.V., Ivanov Yu.D., Glover V., Medvedev A.E., Interaction of pyruvate kinase with isatin and deprenyl, Biomeditsinskaya khimiya, 2006, vol: