Premium
Covalent and non‐covalent interaction of chymotrypsin with α 2 ‐macroglobulin
Author(s) -
Pochon François,
Tourbez Martine,
Favaudon Vincent,
Delain Etienne
Publication year - 1987
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(87)81251-6
Subject(s) - covalent bond , chymotrypsin , chemistry , cleave , hydroxylamine , trypsin , cleavage (geology) , monomer , protein subunit , protease , polyacrylamide gel electrophoresis , gel electrophoresis , stereochemistry , biochemistry , enzyme , organic chemistry , biology , paleontology , fracture (geology) , gene , polymer
The pattern of covalent crosslinking between human α 2 ‐macroglobulin (α 2 M) and chymotrypsin has been investigated by chromatography and polyacrylamide gel electrophoresis in denaturing medium. Reaction with a single mol of chymotrypsin per mol α 2 M results in the formation of a 95% covalent 1:1 chymotrypsin‐α 2 M complex and in the proteolytic cleavage of both 180 kDa monomers in one α 2 M subunit. Proteolytic cleavage in the other α 2 M subunit requires the presence of a second mol of chymotrypsin; part (20%) of the protease in the 2:1 chymotrypsin‐α 2 M complex thus formed appears to be non‐covalently bound to the α 2 M chains. Covalent binding is abolished when the reaction of α 2 M with the protease is carried out in the presence of hydroxylamine. A single mol of the protease is then able to cleave all four 180 kDa monomers in α 2 M.