Isolation and partial characterization of rat elastolytic enzymes from various cells and tissues

Different elastolytic enzymes were isolated from rat aorta and platelets, as well as from granulocyte and pancreatic extracts. The active fractions were purified to electrophoretic apparent homogeneity by precipitation with ammonium sulfate, sequential batch fractionation on DEAE-Sephadex A-50, and finally by isoelectric focusing (IF) on Sephadex G-75 Superfine. The molecular weight and the isoelectric point of the isolated enzymes were estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and by analytical IF, respectively. All the enzymes have elastolytic activity as well as activity toward Suc-(Ala)3-NA. The inhibition profile of the different isolated enzymes toward various inhibitors indicates that aortic, pancreatic, and granulocyte enzymes all belong to the group of serine proteinases, unlike the platelet elastase which is a metalloproteinase.