I present the first clear evidence that the protein: FAD ratio in human monoamine oxidase A and bovine monoamine oxidase B has an upper limit of 65 kDa and 57 kDa per FAD, respectively. To now it had been assumed that the protein: FAD ratio was 100-120 kDa to 1 FAD and that there was one FAD per two subunits which were assumed to be of the same size. For the present work the purity of monoamine oxidase A and monoamine oxidase B was improved over that previously achieved. Protein was determined by quantitative amino acid analysis and FAD content was measured by spectrophotometric titration of SDS-denatured enzyme with NaS2O4 standardized against riboflavin. The cause of the previous misassignment of the protein: FAD ratio was judged as having been due to the use of impure enzyme preparations. Knowledge of the correct protein: FAD ratio is important in devising cloning strategies for this enzyme, in understanding its structure, function, mechanism, and in the studies of its biosynthesis.
Research Article|June 15 1989
Monoamine oxidase A from human placenta and monoamine oxidase B from bovine liver both have one FAD per subunit
Biochem J (1989) 260 (3): 725-729.
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W Weyler; Monoamine oxidase A from human placenta and monoamine oxidase B from bovine liver both have one FAD per subunit. Biochem J 15 June 1989; 260 (3): 725–729. doi: https://doi.org/10.1042/bj2600725
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