crystal structure of human insulin-degrading enzyme in complex with insulin B chaincrystal structure of human insulin-degrading enzyme in complex with insulin B chain

Structural highlights

2g56 is a 4 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.2Å
Ligands:
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

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.[1] [2] [3]

Evolutionary Conservation

 

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

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[4]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. 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
  2. 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
  3. 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
  4. 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

2g56, resolution 2.20Å

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