TY - JOUR
T1 - Insulin-Degrading Enzyme in a Human Colon Adenocarcinoma Cell Line (Caco-2)
AU - Bai, Jane P.F.
AU - Hsu, Matt J.P.
AU - Shier, W. Thomas
PY - 1995/4
Y1 - 1995/4
N2 - The activity of insulin-degrading enzyme (IDE), a thiol metalloprotease degrading insulin in many insulin target cells, was determined in human colon adenocarcinoma (Caco-2) cells. Insulin-degrading activity was localized in the cytosol of Caco-2 cells, accounting for 88% of total activity. Western blots and immunoprecipitation showed that IDE was present in the cytosol of Caco-2 cells and contributed to more than 93% cytosolic insulin-degrading activity. Cytosolic insulin degradation was strongly inhibited by IDE inhibitors, including N-ethylmaleimide, 1,10-phenanthroline, p-chloromericuribenzoate, and EDTA, but was not significantly or not as extensively inhibited by strong inhibitors of proteasome, i.e., chymostatin, soybean trypsin inhibitor, leupeptin, and Dip-F. These results suggest that IDE is present in Caco-2 cells, that Caco-2 IDE has properties similar to those of its counterparts in insulin-target tissues, and that it significantly contributes to intracellular insulin degradation.
AB - The activity of insulin-degrading enzyme (IDE), a thiol metalloprotease degrading insulin in many insulin target cells, was determined in human colon adenocarcinoma (Caco-2) cells. Insulin-degrading activity was localized in the cytosol of Caco-2 cells, accounting for 88% of total activity. Western blots and immunoprecipitation showed that IDE was present in the cytosol of Caco-2 cells and contributed to more than 93% cytosolic insulin-degrading activity. Cytosolic insulin degradation was strongly inhibited by IDE inhibitors, including N-ethylmaleimide, 1,10-phenanthroline, p-chloromericuribenzoate, and EDTA, but was not significantly or not as extensively inhibited by strong inhibitors of proteasome, i.e., chymostatin, soybean trypsin inhibitor, leupeptin, and Dip-F. These results suggest that IDE is present in Caco-2 cells, that Caco-2 IDE has properties similar to those of its counterparts in insulin-target tissues, and that it significantly contributes to intracellular insulin degradation.
KW - Caco-2 cells
KW - insulin-degrading enzyme
UR - http://www.scopus.com/inward/record.url?scp=0028948310&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028948310&partnerID=8YFLogxK
U2 - 10.1023/A:1016241610649
DO - 10.1023/A:1016241610649
M3 - Article
C2 - 7596985
AN - SCOPUS:0028948310
SN - 0724-8741
VL - 12
SP - 513
EP - 517
JO - Pharmaceutical Research: An Official Journal of the American Association of Pharmaceutical Scientists
JF - Pharmaceutical Research: An Official Journal of the American Association of Pharmaceutical Scientists
IS - 4
ER -