LED fluorescence spectroscopy for direct determination of monoamine oxidase B inactivation.
In this work, we report an alternative assay for the determination of the inhibitory effect on monoamine oxidase B (MAO-B) activity of probe compounds. Enzyme MAO-B exhibits fluorescence emissions when it is excited at 412 nm. Using an inexpensive blue LED-like excitation source, we measured the quenching of fluorescence intensity of MAO-B enzyme during the reaction with inhibitors. The applicability of the procedure is demonstrated by assays with l-deprenyl and berberine as inhibitors through the use of fluorescence studies. The IC(50) values of l-deprenyl and berberine were 0.04 and 90 microM, respectively. The K(I) values were 0.020 and 47 microM for l-deprenyl and berberine, respectively. These IC(50) and K(I) values were similar to the values obtained with a standard method. These results demonstrate the feasibility of this method as an alternative to follow the inhibitory effect on MAO-B.
Castillo
J
J
Escuela de Química, Universidad Central de Venezuela, Los Chaguaramos, Caracas 1080A, Venezuela. jimmy@strix.ciens.ucv.ve
Hung
J
J
Rodriguez
M
M
Bastidas
E
E
Laboren
I
I
Jaimes
A
A
D000818:Animals; D001596:Benzylamines / Q000737:chemistry; D001599:Berberine / Q000737:chemistry / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007700:Kinetics; D008027:Light; D051379:Mice; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism; D008995:Monoamine Oxidase / Q000378:metabolism*; D008996:Monoamine Oxidase Inhibitors / Q000378:metabolism; D012642:Selegiline / Q000737:chemistry / Q000494:pharmacology; D013050:Spectrometry, Fluorescence / Q000379:methods*
D001596:Benzylamines; D008996:Monoamine Oxidase Inhibitors; D001599:Berberine; D012642:Selegiline; C030796:benzylamine; D008995:Monoamine Oxidase