... site of covalent attachment of FAD and confirmed Trp66 asessential for FAD binding, f or enzyme activity and for thespectral properties o f the wild-type enzyme. A Km of 140 lM and a kcat of ... Biochemistry and Molecular Biology, University of Freiburg, Freiburg, Germany;2Laboratory of Biochemistry, University of Groningen, the Netherlands;3Institute of Organic Chemistry and Biochemistry, ... Identifi-cation by TLC of c-aminobutyrate as the reaction product of MABO.One microlitre of a 10 mMsolution of c-aminobutyrate (lanes 2 and 9);1 lLofa10mMsolution of c-N-m ethylaminobutyrate...