Several aspects on the amine oxidation by semicarbazide-sensitive amine oxidase (SSAO) from bovine lung

The lung has been shown to be potentially important in the metabolism of amines. Since SSAO has been demonstrated to be active towards some volatile short-chain aliphatic amines in other tissues, the current study determined the specificity and kinetic constants for the metabolism by bovine lung SSAO, of several aliphatic and aromatic amines some of which have been suggested to be physiological substrates (e.g. methylamine, aminoacetone and beta-phenylethylamine), and others (e.g. benzylamine) which are non-physiological. In the case of benzylamine, an inhibition at high substrate concentration was observed. Kinetic assays ruled out the possibility that this inhibition was caused by products of the deamination of benzylamine, and consequently it is suggested that these results may indicate the presence of two binding sites for the interaction of benzylamine with SSAO.