3CWW

Crystal Structure of IDE-bradykinin complex

3CWW の概要

• エントリーDOI: 10.2210/pdb3cww/pdb
• 関連するPDBエントリー: 2G47 2JG4
• 分子名称: Insulin-degrading enzyme, bradykinin N-terminal tetrapeptide analogue, ZINC ION, ... (6 entities in total)
• 機能のキーワード: a-beta degrading enzyme, criptidase, bradykinin, kinins, hydrolase
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Cytoplasm: P14735
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 229304.16

構造登録者

Malito, E.,Tang, W.J. (登録日: 2008-04-23, 公開日: 2008-11-25, 最終更新日: 2023-08-30)

主引用文献

Malito, E.,Ralat, L.A.,Manolopoulou, M.,Tsay, J.L.,Wadlington, N.L.,Tang, W.J.
Molecular Bases for the Recognition of Short Peptide Substrates and Cysteine-Directed Modifications of Human Insulin-Degrading Enzyme
Biochemistry, 47:12822-12834, 2008

PubMed Abstract: Insulin degrading enzyme (IDE) utilizes a large catalytic chamber to selectively bind and degrade peptide substrates such as insulin and amyloid beta (Abeta). Tight interactions with substrates occur at an exosite located approximately 30 A away from the catalytic center that anchors the N-terminus of substrates to facilitate binding and subsequent cleavages at the catalytic site. However, IDE also degrades peptide substrates that are too short to occupy both the catalytic site and the exosite simultaneously. Here, we use kinins as a model system to address the kinetics and regulation of human IDE with short peptides. IDE specifically degrades bradykinin and kallidin at the Pro/Phe site. A 1.9 A crystal structure of bradykinin-bound IDE reveals the binding of bradykinin to the exosite and not to the catalytic site. In agreement with observed high K(m) values, this suggests low affinity of bradykinin for IDE. This structure also provides the molecular basis on how the binding of short peptides at the exosite could regulate substrate recognition. We also found that human IDE is potently inhibited by physiologically relevant concentrations of S-nitrosylation and oxidation agents. Cysteine-directed modifications play a key role, since an IDE mutant devoid of all 13 cysteines is insensitive to the inhibition by S-nitrosoglutathione, hydrogen peroxide, or N-ethylmaleimide. Specifically, cysteine 819 of human IDE is located inside the catalytic chamber pointing toward an extended hydrophobic pocket and is critical for the inactivation. Thiol-directed modification of this residue likely causes local structural perturbation to reduce substrate binding and catalysis.

PubMed: 18986166
DOI: 10.1021/bi801192h

実験手法

X-RAY DIFFRACTION (1.96 Å)