Insulin Degrading Enzyme (IDE)

Insulin Degrading Enzyme (IDE) is a large zinc-binding protease of the M16A metalloprotease subfamily known to cleave multiple short polypeptides that vary considerably in sequence. IDE was first identified by its ability to degrade the B chain of the hormone insulin. This activity was observed over fifty years ago, though the enzyme specifically responsible for B chain cleavage was identified more recently. This discovery revealed considerable amino acid sequence homology between IDE and the previously characterized bacterial protease pitrilysin, suggesting a common proteolytic mechanism. IDE, which migrates at 110 kDa during gel electrophoresis under denaturing conditions, has since been shown to have additional substrates, including the signaling peptides glucagon, TGF alpha, and beta-endorphin.