*4.2. Purification of Recombinant GOX Proteins, SDS-PAGE and Determination of FMN Content*

GOX proteins were purified as described by Dellero et al. [34]. The purity of each recombinant GOX protein was checked by SDS-PAGE (10% acrylamide) stained with Coomassie Brilliant Blue [41]. Recombinant GOX proteins used to measure FMN content were purified without FMN in buffers and FMN levels were evaluated by spectrophotometry using the A280/A450 nm ratio.
