The present invention provides kPGE and derivative polypeptides which are capable of being produced by genetic recombination and used to produce EMCs. This invention further provides nucleic acid sequences encoding kPGE and derivative polypeptides which can be used to create recombinant host cells that express kPGE and derivative polypeptides. A further subject of the present of invention is a fusion polypeptide called polyHis-enterokinase which increases expression of esterases and lipases when fused to the N-terminal of the esterase or lipase. This invention also provides a method for treating animals with an esterase or lipase deficiency by administering rkPGE to the animal in a therapeutically effective amount.