Mechanistic studies on ethanolamine ammonia lyase

Ethanolamine ammonia lyase catalyzes the deamination of ethanolamine to form acetaldehyde and ammonia - a transformation that requires coenzyme 612- The function of coenzyme 612 is to abstract a hydrogen atom from C1 of the substrate, ethanolamine, to generate a free radical intermediate. This intermediate then rearranges to form a product radical which reacquires the hydrogen that had been abstracted from C1. Deamination of the carbinolamine affords acetaldehyde and ammonia. The participation of free radical intermediates in this reaction was shown two decades ago. We have utilized electron paramagnetic resonance and UV/vis spectroscopies to gain insights into the interaction of holoenzyme with substrates and with substrate analogs.