posted on 2021-10-11, 13:34authored byCyril Aselmeyer, Bertrand Légeret, Anaïs Bénarouche, Damien Sorigué, Goetz Parsiegla, Fred Beisson, Frédéric Carrière
Fatty
acid photodecarboxylase (FAP), one of the few natural photoenzymes
characterized so far, is a promising biocatalyst for lipid-to-hydrocarbon
conversion using light. However, the optimum supramolecular organization
under which the fatty acid (FA) substrate should be presented to FAP
has not been addressed. Using palmitic acid embedded in phospholipid
liposomes, phospholipid-stabilized microemulsions, and mixed micelles,
we show that FAP displays a preference for FAs present in liposomes
and at the surface of microemulsions. The kinetics of adsorption onto
phospholipid and galactolipid monomolecular films further suggests
the ability of FAP to bind to and penetrate into membranes, with a
higher affinity in the presence of FAs. The FAP structure reveals
a potential interfacial recognition site with clusters of hydrophobic
and basic residues surrounding the active site entrance. The resulting
dipolar moment suggests the orientation of FAP at negatively charged
interfaces. These findings provide important clues about the mode
of action of FAP and the development of FAP-based bioconversion processes.