Human inter-alpha-trypsin inhibitor: localization of the Kunitz-type domains in the N-terminal part of the molecule and their release by a trypsin-like proteinase.
The N-terminal amino-acid sequence of human ITI has been found to be identical with that of the acid-stable human 30-kDa inhibitors (HI-30) from urine, serum, and those released from inter-alpha-trypsin inhibitor by trypsin or chymotrypsin. Serum HI-30 and HI-30 released by trypsin differ from the urinary inhibitor by an additional C-terminal arginine residue. Compared to these two inhibitors the inhibitor released by chymotryptic proteolysis is elongated C-terminally by an additional phenylalanine residue. These results strongly favour HI-30 as the N-terminus of the inter-alpha-trypsin inhibitor and its release from this inhibitor in vivo by cleavage of the Arg123-Phe124 peptide bond by trypsin-like proteinases.
Reisinger
P
P
Hochstrasser
K
K
Albrecht
G J
GJ
Lempart
K
K
Salier
J P
JP
D000510:Alpha-Globulins / Q000097:blood / Q000652:urine; D000595:Amino Acid Sequence; D002918:Chymotrypsin; D006801:Humans; D008970:Molecular Weight; D010446:Peptide Fragments / Q000032:analysis*; D014357:Trypsin; D014360:Trypsin Inhibitor, Kunitz Soybean; D014361:Trypsin Inhibitors
D000510:Alpha-Globulins; D010446:Peptide Fragments; D014361:Trypsin Inhibitors; C011877:inter-alpha-inhibitor; D014360:Trypsin Inhibitor, Kunitz Soybean; D002918:Chymotrypsin; D014357:Trypsin