Ensemble cryoEM elucidates the mechanism of insulin capture and degradation by human insulin degrading enzyme

eLife

Hui Wei¹  Wei-Jen Tang²  Sheng Li²  Anthony A Kossiakoff³  Clinton S Potter³  Virgil A Woods⁴  David Lee⁴  Mara Farcasanu⁴  Wenguang G Liang⁴  Rebecca Deprez-Poulain⁵  Lucas J Bailey⁶  Akiko Koide⁷  Weifeng Shang⁸  Lauren A McCord⁸  Andrew Wang⁹  Yong Zi Tan⁹  Zhening Zhang⁹  Shohei Koide^1,10  Bridget Carragher^1,10  Benoit Deprez^1,11  David R Liu^1,11 

[1] Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States;Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, United States;New York University Langone Medical Center, New York University School of Medicine, New York, United States;Ben-May Institute for Cancer Research, The University of Chicago, Chicago, United States;BioCAT, Argonne National Laboratory, Illinois, United States;Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, United States;Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States;Department of Medicine, University of California, San Diego, La Jolla, United States;National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, United States;Perlmutter Cancer Center, New York University School of Medicine, New York, United States;Univ. Lille, INSERM, Institut Pasteur de Lille, Lille, France;

关键词: insulin;    amyloid peptide;    insulin degrading enzyme;    proteostasis;    cryoEM;    integrative structural biology;   

DOI  :  10.7554/eLife.33572

来源: DOAJ

【 摘 要 】

Insulin degrading enzyme (IDE) plays key roles in degrading peptides vital in type two diabetes, Alzheimer's, inflammation, and other human diseases. However, the process through which IDE recognizes peptides that tend to form amyloid fibrils remained unsolved. We used cryoEM to understand both the apo- and insulin-bound dimeric IDE states, revealing that IDE displays a large opening between the homologous ~55 kDa N- and C-terminal halves to allow selective substrate capture based on size and charge complementarity. We also used cryoEM, X-ray crystallography, SAXS, and HDX-MS to elucidate the molecular basis of how amyloidogenic peptides stabilize the disordered IDE catalytic cleft, thereby inducing selective degradation by substrate-assisted catalysis. Furthermore, our insulin-bound IDE structures explain how IDE processively degrades insulin by stochastically cutting either chain without breaking disulfide bonds. Together, our studies provide a mechanism for how IDE selectively degrades amyloidogenic peptides and offers structural insights for developing IDE-based therapies.

【 授权许可】

Unknown