Rat plasma alpha 1-inhibitor3: a member of the alpha-macroglobulin family.
The overall mechanism of interaction with proteinases of alpha 1-inhibitor3, a plasma proteinase inhibitor so far specific to the rat, has been shown to be closely similar to that described for alpha-macroglobulins. This mechanism includes: (i) the cleavage of at least one susceptible peptidic bond which leads to structural changes in the molecule. (ii) The cleavage of a putative thiol ester bond in another site of the molecule which permits the covalent linkage of the enzyme. Moreover, fragmentation of alpha 1-inhibitor3 upon heating as observed for alpha-macroglobulin quarter subunits has been demonstrated. The question is raised of the presence of such a molecule in rat plasma in addition to two alpha-macroglobulin species, all of these proteinase inhibitors being antigenically unrelated.
Esnard
F
F
Gutman
N
N
el Moujahed
A
A
Gauthier
F
F
D000209:Acute-Phase Proteins; D000818:Animals; D002918:Chymotrypsin / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008433:Mathematics; D008970:Molecular Weight; D011480:Protease Inhibitors / Q000032:analysis*; D051381:Rats; D000511:alpha-Macroglobulins / Q000032:analysis*
D000209:Acute-Phase Proteins; D011480:Protease Inhibitors; C017894:alpha 1-inhibitor 3; D000511:alpha-Macroglobulins; D002918:Chymotrypsin