There are at least 6 isoenzyme (may be different genes Q9TS80 PLE1 A5A4F5 PLE3). Isoenzymes of pig-liver esterase reveal striking differences in enantioselectivities Hummel et al. 2007. Polyisoprenylated. methylated protein methyl esterase (PMPMEase). Pig liver esterase 5 (PLE5) (pig-a9gyw6) is the isoenzyme crystallized (5FV4)