The bacteriocin release protein (BRP) mediated release of several eukaryotic proteins was studied in Escherichia coil. The genes for the plant proteins a-galactosidase and thaumatin, and for the mammalian proteins prochymosine and prophospholipase A(2), were cloned behind the OmpA signal peptide. The alpha-galactosidase was expressed and secreted into the periplasm. Prochymosine and thaumatin were poorly expressed. Release experiments showed that about 5 mg/l of alpha-galactosidase was excreted into the extracellular medium upon induction of the BRP.