Slow migrating proteinase inhibitors in human serum.

Employing a sensitive semi-quantitative electrophoretic-technique on acid-deproteinized serum, we found two previously unrecognized trypsin inhibitors migrating as beta 2- and gamma-globulins, respectively. The two inhibitory bands were also detected in native serum. They were not seen in 3 healthy persons, but were found in patients with uremia, cancer, inflammatory diseases and collagenosis. Immunological investigations showed no cross-reaction with antibodies against seven well-known proteinase inhibitors. The two trypsin inhibitors also inhibited pancreatic elastase.