Engineering Fatty Acid Photodecarboxylase to Enable Highly Selective Decarboxylation oftransFatty Acids

Due to the high risk of heart disease caused by the intake of trans fatty acids, a method to eliminate trans fatty acids from foods has become a critical issue. Herein, we engineered fatty acid photo-decarboxylase from Chlorella variabilis (CvFAP) to selectively catalyze the decarboxylation of trans fatty acids to yield readily-removed hydrocarbons and carbon dioxide, while cis fatty acids remained unchanged. An efficient protein engineering based on FRISM strategy was implemented to intensify the electronic interaction between the residues and the double bond of the substrate that stabilized the binding of elaidic acid in the channel. For the model compounds, oleic acid and elaidic acid, the best mutant, V453E, showed a one-thousand-fold improvement in the trans-over-cis (ToC) selectivity compared with wild type (WT). As the first report of the direct biocatalytic decarboxylation resolution of trans/cis fatty acids, this work offers a safe, facile, and eco-friendly process to eliminate trans fatty acids from edible oils.