Purification of alpha 2-macroglobulin with trypsin-like activity from pleural fluids.

An alpha 2-macroglobulin with trypsin-like activity has been purified from pleural fluids of patients suffering from chronic pancreatitis. The isolation procedure includes ammonium sulphate precipitation, gel-filtration on Sephadex G-200 and DEAE-cellulose chromatography. It gives 46-fold purification of alpha 2-macroglobulin with a 13% recovery. Based on titration experiments with pancreatic inhibitor, the protein from three different patients contained 0.28, 0.46 and 0.80 mol of trypsin-like protease per mol of alpha 2-macroglobulin.