Fatty acid photodecarboxylase

Fatty acid photodecarboxylase (FAP) is an enzyme that converts exogenous fatty acids to alkanes or alkenes by the separation of carbon dioxide from the carboxylic group. The photoenzyme "Cv"FAP has been found in the chloroplast membrane of microalgae "Chlorella variabilis NC64A" and "Chlamydomonas reinhardtii 137C"; other FAP examples include flavin‐dependent DNA‐repair enzymes and protochlorophyllide oxidoreductases.
Structure.
The crystallized structure of FAP shows a hydrophobic tunnel consisting of three domains. The inner FAP binding site is flanked by the domain loops that protect it from interacting with solvent. The C-terminal regulates interactions with other proteins and the N-terminal residues on the helical end stabilizes the neighboring tricyclic ring FAD cofactor.
Function.
Flavin adenine dinucleotide (FAD) is found to be responsible for capturing light photons that drive the reaction, with the overall FAP efficiency being dependent on both its enzyme concentration and the light intensity. Experimental studies show photon excited FAD react most favorably under continuous blue light (400-520nm) which produce carbon dioxide from the hydrolysis of fatty acid chains.
FAP’s catalytic activity is proportional to the length of the fatty acid chain due to the number of hydrophobic chains present in the hydrophobic tunnel that stabilize substrates. FAP preference to long-chain fatty acid produces higher turnover rate for hydrocarbons, which can then, in principle, be produced as biofuel as a favored alternative.