National Institutes of Health/National Human Genome Research Institute (NIH/NHGRI)
R01-HL12565
米国
National Institutes of Health/National Human Genome Research Institute (NIH/NHGRI)
R35-GM122510
米国
引用
ジャーナル: Proc Natl Acad Sci U S A / 年: 2020 タイトル: The structure of helical lipoprotein lipase reveals an unexpected twist in lipase storage. 著者: Kathryn H Gunn / Benjamin S Roberts / Fengbin Wang / Joshua D Strauss / Mario J Borgnia / Edward H Egelman / Saskia B Neher / 要旨: Lipases are enzymes necessary for the proper distribution and utilization of lipids in the human body. Lipoprotein lipase (LPL) is active in capillaries, where it plays a crucial role in preventing ...Lipases are enzymes necessary for the proper distribution and utilization of lipids in the human body. Lipoprotein lipase (LPL) is active in capillaries, where it plays a crucial role in preventing dyslipidemia by hydrolyzing triglycerides from packaged lipoproteins. Thirty years ago, the existence of a condensed and inactive LPL oligomer was proposed. Although recent work has shed light on the structure of the LPL monomer, the inactive oligomer remained opaque. Here we present a cryo-EM reconstruction of a helical LPL oligomer at 3.8-Å resolution. Helix formation is concentration-dependent, and helices are composed of inactive dihedral LPL dimers. Heparin binding stabilizes LPL helices, and the presence of substrate triggers helix disassembly. Superresolution fluorescent microscopy of endogenous LPL revealed that LPL adopts a filament-like distribution in vesicles. Mutation of one of the helical LPL interaction interfaces causes loss of the filament-like distribution. Taken together, this suggests that LPL is condensed into its inactive helical form for storage in intracellular vesicles.