A direct continuous fluorometric turn-on assay for monoamine oxidase B and its inhibitor-screening based on the abnormal fluorescent behavior of silole

As essential enzymes in the body, monoamine oxidases (MAOs), including MAO-B, help maintain the proper balance of neurotransmitters and other dietary and biogenic amines. Thus, development of convenient and continuous assays for MAO-B and its inhibitor-screening is highly desirable since the inhibitors have implications for therapeutics for many brain diseases. In this paper, we report a direct continuous fluorescence turn-on assay for MAO-B and its inhibitor-screening with the ensemble of silole 1, heptylamine and HSO(3)(-), which are either easily accessible or commercially available. Fluorescent spectral investigations show that this fluorometric assay can be performed continuously in aqueous solution and MAO-B of concentrations as low as 0.25 mu g/mL can be analyzed. Moreover, the ensemble of silole 1, heptylamine, HSO(3)(-) and MAO-B can be employed to screen the inhibitors of MAO-B.