Transamination and Oxidative Deamination Catalyzed by Dihydroxyphenylalanine DOPA Decarboxylase

5-hydroxytryptophan to yield serotonin (5-hydroxytryptamine). Early studies suggested that it wtis especitdly susceptible to self-inactivation as a result of catcdyzing the hcdf-reaction of transamination (Section 9.3.1.5). However, it only catalyzes half-tremstunination under anaerobic conditions (commonly used in vitro because of the ready polymerization of DOPA emd dopamine to yield melanin in the presence of oxygen). Under aerobic conditions, the enzyme does not seem to catalyze half-tremstunination, but it does cattdyze oxidative deeimination of its tuomatic tunine products (Bertoldi and Borri Voltattorni, 2000, 2001). 

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