SDS-PAGE analysis of GST-PCT–N complexes purified from E. coli. Samples were denatured in Laemmli buffer, run on 10% polyacrylamide gels and detected with Coomassie brilliant blue staining. The PCT–N complexes bound to glutathione-Sepharose beads were incubated with thrombin overnight at 20 °C. After centrifugation, beads or supernatant were loaded (2 µL per lane). A = beads before cleavage; B = beads after cleavage; C = Supernatant containing soluble PCT + N; protein molecular size standards (kDa) are on the left.