Effects of metalloendoprotease inhibitors on insulin binding, internalization and processing in adipocytes
Jochen, A.; Berhanu, P.
Biochemical and Biophysical Research Communications 142(1): 205-212
1987
ISSN/ISBN: 0006-291X PMID: 3545203 Document Number: 292789
The effects of metalloendoprotease inhibitors on insulin binding, internalization, and processing were studied in isolated rat adipocytes. The metalloendoprotease inhibitor phosphoramidon caused a marked (threefold) increase in intracellular insulin accumulation without affecting surface binding. The dipeptide metalloendoprotease substrate analogues benzyloxycarbonyl-Gly-Phe-NH2 and benzyloxycarbonyl-Gly-Leu-NH2 caused similar large increases in intracellular insulin but also caused a doubling of cell surface bound insulin. The effect on surface binding was due to increased insulin receptor affinity as demonstrated by Scatchard analysis and the benzyloxycarbonyl-Gly-Phe-NH2 induced inhibition of the dissociation of prebound insulin from the cell surface. These results suggest a role for endogenous metalloendoprotease-like enzymes in insulin processing by rat adipocytes.