Human renin has been expressed in Sf9 and CHO cells using two different gene constructs. The first construct contained a foreign signal peptide fused directly to the sequence encoding mature renin, whereas the second construct harbors the sequence for preprorenin. Prorenin was produced in significantly higher amounts than the mature enzyme expressed without its propeptide in both expression systems. Both directly expressed mature renin and proteolytically derived active renin have been purified and cocrystallized with the renin inhibitor Ro 42-5892. The 3D structure has been solved for both versions and demonstrates identity despite different glycosylation and different N termini.