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Autolysis of proproteinase E in bovine procarboxypeptidase A ternary complex gives rise to subunit III
Author(s) -
Pascual Roger,
Vendrell Josep,
Avilés Francesc X.,
Bonicel Jacques,
Wicker Catherine,
Puigserver Antoine
Publication year - 1990
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(90)80804-r
Subject(s) - autolysis (biology) , protein subunit , chemistry , carboxypeptidase , chymotrypsinogen , biochemistry , ternary complex , subtilisin , enzyme , protease , microbiology and biotechnology , biology , trypsin , chymotrypsin , gene
Extracts of bovine pancreatic tissue are shown by HPLC to contain two distinct ternary complexes of procarboxypeptidase A (subunit I), chymotrypsinogen C (subunit II) and either proproteinase E or subunit III. It is shown that proproteinase E in the complex generates subunit III by removal of 13 N‐terminal residues when the former is allowed to autolyze in solution or when catalytic amounts of isolated active proteinase E are added to it. Autolysis of proproteinase E was accompanied by the loss of potential activity towards specific synthetic substrates and occurred at a higher rate in pancreatic juice than in pancreatic tissue extracts, even when both were processed in the presence of serine protease inhibitors. We conclude that subunit III (also called truncated protease E) is an autolytic product of proproteinase E and not an ab initio component of the native ternary complex.