title: Susceptibility of platelet alpha-actinin to a Ca2+-activated neutral protease.
abstract: Purified alpha-actinin from human platelets was digested with Ca2+-activated protease from muscle. The alpha subunit (Mr = 100 kDa) was degraded into a unique polypeptide b of slightly lower molecular mass. In fresh platelets, only the a subunit was detected by immunoblotting techniques, while in out-dated platelets, both a and b polypeptides were present. Since a similar conversion of a to b occurs in vitro as in whole platelets, it can be assumed that, in platelets, alpha-actinin is cleaved by the endogenous Ca2+-activated protease.
mesh_terms: D000185:Actinin / Q000097:blood*; D001792:Blood Platelets / Q000378:metabolism*; D002154:Calpain; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000378:metabolism*; D006801:Humans; D046911:Macromolecular Substances; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology
chemical_list: D046911:Macromolecular Substances; D000185:Actinin; D010450:Endopeptidases; D002154:Calpain