Proteolysis of ankyrin and Na+/K(+)-ATPase in postmortem rat brain: is calpain involved?
Ankyrin links the fodrin-based cytoskeleton to membrane proteins such as Na+/K(+)-ATPase, thereby maintaining cellular integrity. Immunoblotting by antibody raised against erythrocyte ankyrin demonstrated the proteolysis of ankyrin, which was highly correlated with postmortem interval (0-24 h). Proteolysis in the postmortem brain generated the 160-kDa fragment with an identical size as the fragment formed after in vitro proteolysis by calpain. Although microM Ca2+ induced the proteolysis in the homogenate, the presence of mu-calpain was not demonstrated by immunoblotting using the antibody that reacts with large subunits both of mu- and m-calpains. Na+/K(+)-ATPase was also proteolyzed in the postmortem brain.
Harada
K
K
Department of Legal Medicine, Yamaguchi University School of Medicine, Japan.
Sorimachi
Y
Y
Yoshida
K
K
D000818:Animals; D017487:Ankyrins / Q000378:metabolism*; D001921:Brain / Q000201:enzymology / Q000378:metabolism*; D002154:Calpain / Q000032:analysis / Q000502:physiology*; D004591:Electrophoresis, Polyacrylamide Gel; D008297:Male; D011180:Postmortem Changes; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D017487:Ankyrins; D002154:Calpain; D000254:Sodium-Potassium-Exchanging ATPase