ABSTRACT
This suggests that amine oxidases would exhibit ping-pong steady-state kinetics, which has been confirmed for the CAOs from porcine serum [161] and bovine serum [162]. However, this is probably an oversimplification since the observation of sub strate inhibition at high substrate concentrations [163] cannot be explained by such a mechanism, which raises the possibility that the catalytic activity might be regulated. From the viewpoint of the chemistry occurring at the active site, it is more useful to state that amine oxidases follow an aminotransferase mechanism as summarized by the above equations. Thus NH3 is released in the oxidative half cycle [164,165] and the Ered form of the enzyme has the trihydroxyphenylalanine cofactor in the aminoquinol form TOPANH2 where the nitrogen atom of the aminoquinol is derived from substrate [166].
