Screen of monoamine oxidase inhibitors by protein-liposome conjugate capillary electrophoresis

Based on the interaction between enzyme and substrate, a simple and elegant method was developed to screen the inhibitors of monoamine oxidase (MAO). Four kinds of N-propargyl amine compounds with gradient concentrations were added in the CE running buffer solution containing protein-liposome conjugate to inhibit the activity of MAO to some extent. The relative migration time ratio (RMTR) of Kyn was investigated in running buffer solution containing different compounds in gradient concentrations. The results indicate that R-N-(2-heptyl)-N- methylpropargylamine (R-2-HMP) and N-propargyl-R-2-heptylamine (R-2-HPA) could inhibit the activity of MAO obviously, such that the interaction between MAO and Kyn was weakened, RMTR of Kyn increased with the increase of R-2-HMP and R-2-HPA. The inhibition activities of N-dipropargyl-R-2-hexylamine and N, N-dipropargyl-R-2-octylamine were not obvious; RMTR of Kyn changed little with the increase of the two compounds. This result was consistent with that of activity assay of compounds incubation offline. In comparison with the traditional screening method for MAO inhibitors, this method is rapid, low cost, less consumption of enzyme and independent of voltage and other interference factors.