A Method for the Separation and Detection of Proteases Using Substrate-containing Gel Isoelectric Focusing Electrophoresis

We developed an accurate method to separate and detect proteases using isoelectric focusing electrophoresis. The simultaneous addition of 0.3% octyl-D-glucopylanoside or 8M urea to acrylamide gel containing gelatin and of cytochrome c and pl marker proteins to the sample solution prevented interaction between protease and substrate during electrophoresis. Picogram to nanogram quantities of commercial proteases, papain, chymotrypsin, and proteinase K, were detected at the estimative isoelectric point of these proteases.