The two missing enzymes needed to make morphine in plants are revealed in a paper online this week in, Nature Chemical Biology. This finding will enable increased production of this important painkiller and its chemical relatives.
Morphine is created in opium poppy in a long series of steps, but the enzymes needed to catalyze two 'demethylation' steps ― in which a methyl group (or 'CH3') is removed from a molecule ― are currently unknown. Jillian Hagel and Peter Facchini now use a mutant plant as a starting point for their enzymatic detective work. Unexpectedly, the two enzymes they identify are part of a group of enzymes known as dioxygenases that have important roles in epigenetics.
This finding completes the biosynthetic path to this important medicine and so should allow biotechnological strategies to optimize production of morphine as well as to redirect the path to morphine towards related compounds such as codeine and oxycodone.