... (SDS)-polyacrylamide gels for electrophoresis: 4–15% Phast gels were purchased from Pharmacia, L.K.B Biotechnology, Uppsala, Sweden Schiffs reagent, commercial solution (Sigma) Sepharose CL-2B ... Pharmacia Phast-gel system (Pharmacia) Contraves low shear 30 viscometer (Contraves A.G Zurich, Switzerland) Proteinase Activity 397 Methods 3.1 Preparation of Substrate, Blocking of N-Terminals ... exhaustively against distilled water at 4°C, freeze-dry and store the protein substrate with blocked N-terminals at –20°C (see Note 3) 3.1.1 N-Terminal Assay Mix proteinase (see Note 4) or extract...