Screening of the occurrence of copper amine oxidases in Fabaceae plants

Aim of this work was to find the best source for obtaining high amount of copper amine oxidase (EC 1.4.3.6) that can be further used for analytical or industrial applications. The study focused on plant enzymes, because they occur in much higher content in the starting material than the enzymes from other sources, have higher specific activity and are also more thermostable. Presence of the amine oxidase was tested in extracts from 4 to 7-d-old seedlings of thirty-four various Fabaceae plants. Amine oxidases hom nine selected plants were purified by general method involving ammonium sulfate fractionation, controlled heat denaturation, and three chromatographic steps. Kinetic properties of the amine oxidases purified were tested with a wide range of substrates and inhibitors and were found to be very similar. Best purification yield, and total and specific activities were obtained for the enzyme from grass pea (Lathyrus sativus) throughout all purification steps. Hence, the grass pea extract was chosen as a suitable candidate for massive production of the amine oxidase.