Kunitz-Type Proteinase Inhibitors Derived by Limited Proteolysis of the Inter-α-Trypsin Inhibitor, VI. Detection of a Complex Between Immunoglobulin G and the Inhibitory Active Part of the Inter-α-Trypsin Inhibitor

A latent trypsin inhibitor is released from denatured human serum proteins by proteolytic digestion with thermolysin. The latent inhibitor was enriched by chromatography on DEAE-Sephacel, Sephadex G-200, and Protein A-Sepharose, respectively. Immunological cross-section identified the latent inhibitor as a complex between IgG and the inhibitory active part of the inter-alpha-trypsin inhibitor.