Activation of Cytochrome C Peroxidase Function Through Coordinated Foldon Loop Dynamics upon Interaction with Anionic Lipids

JOURNAL OF MOLECULAR BIOLOGY

卷:433

Article

Li, Mingyue^1,8  Sun, Wanyang^2,3  Tyurin, Vladimir A.^2,3  DeLucia, Maria¹  Ahn, Jinwoo¹  Kagan, Valerian E.^2,3,4,5,6  van der Wel, Patrick C. A.^1,7 

[1] Univ Pittsburgh, Dept Struct Biol, Pittsburgh, PA 15213 USA

[2] Univ Pittsburgh, Dept Environm & Occupat Hlth, Pittsburgh, PA 15213 USA

[3] Univ Pittsburgh, Ctr Free Rad & Antioxidant Hlth, Pittsburgh, PA 15213 USA

[4] Univ Pittsburgh, Dept Chem, Pittsburgh, PA 15213 USA

[5] Univ Pittsburgh, Dept Pharmacol & Chem Biol, Pittsburgh, PA 15213 USA

[6] Moscow State Med Univ, Inst Regenerat Med, IM Sechenov, Moscow 119146, Russia

[7] Univ Groningen, Zernike Inst Adv Mat, Nijenborgh 4, NL-9747 AG Groningen, Netherlands

[8] Merck & Co Inc, Pharmaceut Sci, Kenilworth, NJ 07033 USA

关键词: solid-state NMR spectroscopy;    lipid peroxidation;    mitochondrial apoptosis;    lipidomics;    peripheral membrane proteins;   

DOI  :  10.1016/j.jmb.2021.167057

来源: Elsevier

【 摘 要 】

Cardiolipin (CL) is a mitochondrial anionic lipid that plays important roles in the regulation and signaling of mitochondrial apoptosis. CL peroxidation catalyzed by the assembly of CL-cytochrome c (cyt c) complexes at the inner mitochondrial membrane is a critical checkpoint. The structural changes in the protein, associated with peroxidase activation by CL and different anionic lipids, are not known at a molecular level. To better understand these peripheral protein-lipid interactions, we compare how phosphatidylglycerol (PG) and CL lipids trigger cyt c peroxidase activation, and correlate functional differences to structural and motional changes in membrane-associated cyt c. Structural and motional studies of the bound protein are enabled by magic angle spinning solid state NMR spectroscopy, while lipid peroxidase activity is assayed by mass spectrometry. PG binding results in a surface-bound state that preserves a nativelike fold, which nonetheless allows for significant peroxidase activity, though at a lower level than binding its native substrate CL. Lipid-specific differences in peroxidase activation are found to correlate to corresponding differences in lipid-induced protein mobility, affecting specific protein segments. The dynamics of omega loops C and D are upregulated by CL binding, in a way that is remarkably controlled by the protein:lipid stoichiometry. In contrast to complete chemical denaturation, membrane-induced protein destabilization reflects a destabilization of select cyt c foldons, while the energetically most stable helices are preserved. Our studies illuminate the interplay of protein and lipid dynamics in the creation of lipid peroxidase-active proteolipid complexes implicated in early stages of mitochondrial apoptosis. (C) 2021 The Author(s). Published by Elsevier Ltd.

【 授权许可】

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