Vanillyl alcohol oxidase can make vanillin, the major flavour component of vanilla. We have studied this enzyme in great detail to better understand how it works and how exactly it produces vanillin. We have identified two different paths that guide substrates to where the reaction takes place. Once there, some substrates form an adduct, preventing product formation. Based on our work, we predict that the size of the substrate determines if the adduct is formed, and that one amino acid in the active centre of the enzyme is crucial for this process.
Our work will help other researchers to improve this enzyme so that it can make vanillin more efficiently.