Kunitz-type proteinase inhibitors derived by limited proteolysis of the inter-alpha-trypsin inhibitor, I. Determination of the amino acid sequence of the antitryptic domain by solid-phase Edman degradation.
The acid-stable trypsin inhibitor of human serum and urine is released in vivo by limited proteolysis from the high molecular weight, acid-labile inter-alpha-trypsin inhibitor. When complexed with trypsin, both this acid-stable, active derivative and the inter-alpha-trypsin inhibitor can be degraded in vitro by prolonged digestion with trypsin to a low molecular weight "minimal" inhibitor. This minimal trypsin inhibitor was sequenced and found to be homologous to the known Kunitz-type inhibitors (e.g. the basic trypsin-kallikrein inhibitor from bovine organs). This indicates that the antitryptic activity of the big inter-alpha-trypsin inhibitor is due to a Kunitz-type domain.
D000510:Alpha-Globulins; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002918:Chymotrypsin; D006801:Humans; D010446:Peptide Fragments / Q000032:analysis; D011485:Protein Binding; D013045:Species Specificity; D014357:Trypsin / Q000378:metabolism; D014360:Trypsin Inhibitor, Kunitz Soybean; D014361:Trypsin Inhibitors
D000510:Alpha-Globulins; D010446:Peptide Fragments; D014361:Trypsin Inhibitors; D014360:Trypsin Inhibitor, Kunitz Soybean; D002918:Chymotrypsin; D014357:Trypsin