Molecular docking simulations The targets for docking simulations were prepared as previously described by Dettori et al. (2018). Briefly, the CALB cristal structure (PDB entry: 1LBS) that contains ethylhexylphosphonate (HEE) inhibitor covalently bound to the catalytic serine was chosen as starting structure. The inhibitor was removed and acyl-enzyme systems were built by binding the different acyl donors to the catalytic serine. The building strategy consists of following the placement of the inhibitor hexyl chain that was assumed to indicate the localisation of the acyl-enzyme acyl moiety. Then, a structure relaxation procedure was performed with constraints and restraints that were progressively removed in order to preserve the organization of protein atoms. Docking simulations were run using the Flexible Docking module of the software Discovery Studio 4.5. the flexible zone was defined by the residues 40, 105, 106, 134, 140, 141, 144, 149, 154, 157, 187, 189, 224, 278, 281, 282, 285 and 286.