Calpain in cultured bovine lens epithelial cells.
Calcium dependent proteolysis was examined in supernatant prepared from cultured bovine lens epithelial (BLE) cells. The presence of the calcium activated protease, calpain, was indicated by immunorecognition of 80 kDa and 30 kDa subunits of calpain in BLE cell supernatant. Degradation of 125I-alpha-crystallin and FITC labeled casein by BLE cell supernatant were shown to be calcium dependent. Inhibition of activity was achieved with EGTA, calpastatin or CbzValPheH. The data presented are the first measurement of calpain activity in cultured lens cells.
Lipman
R D
RD
Laboratory for Nutrition and Vision Research, USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111.
Cyr
D E
DE
David
L L
LL
Taylor
A
A
D000818:Animals; D001345:Autoradiography; D002154:Calpain / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D003459:Crystallins / Q000378:metabolism; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D015151:Immunoblotting; D007908:Lens, Crystalline / Q000166:cytology / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning
D003459:Crystallins; D002154:Calpain