Kunitz-type proteinase inhibitors derived by limited proteolysis of the inter-alpha-trypsin inhibitor. VI. Detection of a complex between immunoglobulin g and the inhibitory active part of the inter-alpha-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.