Purification and characterization of alpha 1-antichymotrypsin from human pleural fluid and human serum

Human alpha 1-antichymotrypsin was purified from human pleural fluid and from human serum. Four affinity chromatographic steps were required to obtain pure alpha 1-antichymotrypsin. Pleural and serum alpha 1-antichymotrypsin have the same molecular weight, which was estimated by SDS-polyacrylamide gel electrophoresis to be 58 000. The chemical composition of the two types of alpha 1-antichymotrypsin is the same. Using a technique for visualization of the chymotrypsin inhibitors, we showed that the pure alpha 1-antichymotrypsin obtained from the two physiological fluids had its inhibitory capacity preserved.