Synthesis and kinetic evaluation of substrates and inhibitors for kynureninase

Abstract

Kynureninase is a pyridoxal-5’-phosphate (PLP) dependent enzyme in the kynurenine metabolic pathway of L-tryptophan in animals and bacteria. In mammals, this pathway provides a de novo synthesis of NAD(P)+ . The mammalian kynureninase catalyses the hydrolytic cleavage of 3-hydroxy-L-kynurenine to 3-hydroxyanthranilic acid and Lalanine. One of the metabolites in this pathway is quinolininc acid. Quinolinic acid is a neurotoxin if produced in excess of its biosynthetic requirement. Potent inhibitors of this enzyme are required as drug targets for several neurological disorders and other diseases including Alzhemier’s, AIDS related dementia and Huntington’s disease. In the current work, potent inhibitors and substrates for both human and bacterial kynureninase have been synthesized and kinetically evaluated for their enzymatic activity.