|2g47, resolution 2.10Å ()|
|Gene:||IDE (Homo sapiens)|
|Related:||2g48, 2g49, 2g54, 2g56|
Crystal structure of human insulin-degrading enzyme in complex with amyloid-beta (1-40)
Insulin-degrading enzyme (IDE), a Zn2+-metalloprotease, is involved in the clearance of insulin and amyloid-beta (refs 1-3). Loss-of-function mutations of IDE in rodents cause glucose intolerance and cerebral accumulation of amyloid-beta, whereas enhanced IDE activity effectively reduces brain amyloid-beta (refs 4-7). Here we report structures of human IDE in complex with four substrates (insulin B chain, amyloid-beta peptide (1-40), amylin and glucagon). The amino- and carboxy-terminal domains of IDE (IDE-N and IDE-C, respectively) form an enclosed cage just large enough to encapsulate insulin. Extensive contacts between IDE-N and IDE-C keep the degradation chamber of IDE inaccessible to substrates. Repositioning of the IDE domains enables substrate access to the catalytic cavity. IDE uses size and charge distribution of the substrate-binding cavity selectively to entrap structurally diverse polypeptides. The enclosed substrate undergoes conformational changes to form beta-sheets with two discrete regions of IDE for its degradation. Consistent with this model, mutations disrupting the contacts between IDE-N and IDE-C increase IDE catalytic activity 40-fold. The molecular basis for substrate recognition and allosteric regulation of IDE could aid in designing IDE-based therapies to control cerebral amyloid-beta and blood sugar concentrations.
Structures of human insulin-degrading enzyme reveal a new substrate recognition mechanism., Shen Y, Joachimiak A, Rosner MR, Tang WJ, Nature. 2006 Oct 19;443(7113):870-4. Epub 2006 Oct 11. PMID:17051221
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
[IDE_HUMAN] Plays a role in the cellular breakdown of insulin, IAPP, glucagon, bradykinin, kallidin and other peptides, and thereby plays a role in intercellular peptide signaling. Degrades amyloid formed by APP and IAPP. May play a role in the degradation and clearance of naturally secreted amyloid beta-protein by neurons and microglia.
About this Structure
- Shen Y, Joachimiak A, Rosner MR, Tang WJ. Structures of human insulin-degrading enzyme reveal a new substrate recognition mechanism. Nature. 2006 Oct 19;443(7113):870-4. Epub 2006 Oct 11. PMID:17051221 doi:10.1038/nature05143
- ↑ Vekrellis K, Ye Z, Qiu WQ, Walsh D, Hartley D, Chesneau V, Rosner MR, Selkoe DJ. Neurons regulate extracellular levels of amyloid beta-protein via proteolysis by insulin-degrading enzyme. J Neurosci. 2000 Mar 1;20(5):1657-65. PMID:10684867
- ↑ Im H, Manolopoulou M, Malito E, Shen Y, Zhao J, Neant-Fery M, Sun CY, Meredith SC, Sisodia SS, Leissring MA, Tang WJ. Structure of substrate-free human insulin-degrading enzyme (IDE) and biophysical analysis of ATP-induced conformational switch of IDE. J Biol Chem. 2007 Aug 31;282(35):25453-63. Epub 2007 Jul 5. PMID:17613531 doi:10.1074/jbc.M701590200
- ↑ Malito E, Ralat LA, Manolopoulou M, Tsay JL, Wadlington NL, Tang WJ. Molecular Bases for the Recognition of Short Peptide Substrates and Cysteine-Directed Modifications of Human Insulin-Degrading Enzyme. Biochemistry. 2008 Nov 6. PMID:18986166 doi:10.1021/bi801192h