1. PPARα Ligand-Binding Domain Structures with Endogenous Fatty Acids and Fibrates
- Author
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Shotaro Kamata, Takuji Oyama, Kenta Saito, Akihiro Honda, Yume Yamamoto, Keisuke Suda, Ryo Ishikawa, Toshimasa Itoh, Yasuo Watanabe, Takahiro Shibata, Koji Uchida, Makoto Suematsu, and Isao Ishii
- Subjects
Biochemistry ,Molecular Physiology ,Structural Biology ,Protein Structure Aspects ,Science - Abstract
Summary: Most triacylglycerol-lowering fibrates have been developed in the 1960s–1980s before their molecular target, peroxisome proliferator-activated receptor alpha (PPARα), was identified. Twenty-one ligand-bound PPARα structures have been deposited in the Protein Data Bank since 2001; however, binding modes of fibrates and physiological ligands remain unknown. Here we show thirty-four X-ray crystallographic structures of the PPARα ligand-binding domain, which are composed of a “Center” and four “Arm” regions, in complexes with five endogenous fatty acids, six fibrates in clinical use, and six synthetic PPARα agonists. High-resolution structural analyses, in combination with coactivator recruitment and thermostability assays, demonstrate that stearic and palmitic acids are presumably physiological ligands; coordination to Arm III is important for high PPARα potency/selectivity of pemafibrate and GW7647; and agonistic activities of four fibrates are enhanced by the partial agonist GW9662. These results renew our understanding of PPARα ligand recognition and contribute to the molecular design of next-generation PPAR-targeted drugs.
- Published
- 2020
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